Program for 2022 Moratuwa Engineering Research Conference (MERCon)
Wednesday, July 27
Wednesday, July 27 8:00 - 8:30
Wednesday, July 27 8:30 - 9:30
The current premise in classical ML is based on a single node in a centralized and remote data center with full access to a global dataset and a massive amount of storage and computing. Nevertheless, the advent of a new breed of intelligent devices ranging from drones to self-driving vehicles, makes cloud-based ML inadequate. This talk will present the vision of distributed edge intelligence for and over wireless networks, featuring key enablers, architectures, algorithms and some recent results in this exciting and rapidly advancing area.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 613 9660 7203 Passcode: Mercon@G1
Wednesday, July 27 9:30 - 10:30
K2: Keynote 2: Future of Urban Mobility and Infrastructures: From Car-Lite to Electrification and towards Connected Autonomy
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 613 9660 7203 Passcode: Mercon@G1
Wednesday, July 27 11:00 - 12:45
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 613 4160 9422 Passcode: Mercon@T1
- T1-1-1.1 11:00 Value Engineering as a Pragmatic Value Enhancing Tool for Public Sector Construction Projects
Value Engineering is a globally accepted methodical approach, applied within the construction arena of many countries to improve the output. Nevertheless, applications of Value Engineering in public sector construction projects of Sri Lanka are rare. Therefore, this study aimed to identify the challenges that affect the implementation of Value Engineering for the public sector construction projects in Sri Lanka. Two objectives were implemented to achieve above aim as (1) identify the significance of Value Engineering and challenges affect the implementation of Value Engineering for the public sector construction projects in Sri Lanka, and (2) to develop a suitable framework to overcome the challenges affecting the implementation of Value Engineering in public sector construction projects. 23 challenges were identified through a comprehensive literature review and a questionnaire survey was conducted to identify the impact of those challenges and to find out suitable strategies to overcome them. The data were collected from 71 construction industry professionals with Value Engineering knowledge. Then, the RII technique was adopted to rank the challenges based on the collected data. Based on the challenges and the proposed strategies a framework was developed for better adaptation of Value Engineering for the public sector construction projects in Sri Lanka.
- T1-1-1.2 11:15 Appraising Vulnerabilities on Elders and Built Environment of Aging-In-Place in Tropics Using Infrared Thermography
Demographic shifts due to the burgeoning ageing population and increasing global temperatures are synchronized societal challenges of the future. People living in low and middle-income countries are ageing much faster than richer countries and over the next three decades, ageing is predominant in Asia. People ageing in low-income communities of the tropics will become more vulnerable to heat with limitations and conditions of the houses they live. Thus, the study appraises the vulnerabilities of elders and the built environment of aging in place in the tropical city of Colombo, Sri Lanka. The selected cohort is permanently residing in a low-income community. Infrared thermal imagery analysis of elders is evident for a mean skin temperature of 34.9 deg. C, which is 1.9 deg. C above a healthy adult. Mean skin temperature further increases in elders living in detached houses. Houses demonstrate poor ventilation, and overheated interiors with less usable floor area and windows. Additionally, the elders are suffering from long-term illnesses and their income restricts treatments. Thus, the study portrays an overarching social injustice status for ageing population in Sri Lanka and highlight the significance of built environment to ensure healthy aging in warming climates.
- T1-1-1.3 11:30 Development of a Cost-Optimized Model for Evacuation Route Planning for Tsunamis
This paper addresses the problem of planning inland evacuation routes along a given coastal stretch. This study presents a methodology to determine the optimum interval for proving inland evacuation routes within a stretch of the vulnerable coastal area. The developing countries may confront budgetary limitations in providing the required infrastructure to reduce fatalities. The establishment of evacuation routes or structures involves expensive capital and maintenance costs. Policymakers require a scientific basis to evaluate infrastructure provisions to develop emergency response tactics. The proposed methodology looks at the trade-off between the cost of providing infrastructure for evacuation and saving the exposure to the hazard by reducing the time to access an inland route. A total cost model is derived by integrating infrastructure cost and monetizing the value of time that people are exposed to the risk as a function of the uniform spacing between inland evacuation routes. Thus, the spacing between evacuation routes is obtained as a function of the value of time saved from exposure, population density, hazard zone depth, walking speed of individuals, and cost of infrastructure. Thus, the derived model is applied to a case study in Thelwaththa Grama Niladhari Division, severely affected by the 2004 tsunami event.
- T1-1-1.4 11:45 A Conceptual Framework to Understand the Multi-Hazard Early Warning Mechanism in Communication Management
A conceptual model development is a primary mechanism for defining dependencies among parameters. Here, the integration of concepts linked with Multi-Hazard Early Warning mechanism is captured. This became more significant when implementing Disaster Risk Reduction strategies emphasized by the Sendai Framework for Disaster Risk Reduction 2015-2030. Such a warning mechanism is required to ensure that the public at risk is timely alerted and adequately informed. In proper understanding of this mechanism, the conceptual model development is a significant approach. Here, the activity level sequencing was determined with the analytical illustration of the activity concentration and stakeholder level. Recent studies were considered in conceptual model development. For further verification, the reviews obtained from the pilot expert survey were considered. The developed model was checked for applicability considering disaster situations such as Indian Ocean Tsunami in 2004, Cyclone Fani in 2019 and Meethotamulla garbage dump failure in 2017. Here, the activity level concentration variation is categorized based on stakeholder levels which define on the international to community level are captured along with time change. Based on the idealized conceptual framework, the policymakers and associated stakeholders can use this in integrating the guidelines and policy framework which are targeted at Disaster Risk Reduction.
- T1-1-1.5 12:00 Understanding the Interdependency of Resilience Indicators in Green Building Assessment Tools in Sri Lanka: An Application of SWARA Method
Sri Lanka is frequently subjected to disasters caused by adverse natural shocks and climatic stresses. Since the involvement in the green building industry in Sri Lanka as well, it has emphasized the importance of incorporating disaster resilience indicators into Green Building Rating Tools (GBRTs) to ensure that green buildings can withstand adverse natural shocks and climatic stresses. There have been various disputes over the concepts "disaster resilience" and "sustainable development," which have impeded implementation. Therefore, the Stepwise Weight Assessment Ratio Analysis (SWARA) method was used to identify the overall impact of the integration of disaster resilience indicators into a green building framework. It was intended to capture different perspectives of decision-makers on each possible disaster resilience aspect that can be integrated into a GBRT related to the Sri Lankan context. Selected resilience indicators were assessed for their significance in enhancing disaster resilience as well as the sustainability of green buildings. The results have shown that risk avoidance related indicators can enhance the disaster resilience of the building while increasing the sustainability. Conversely, disaster resilience indicators like improved structural and architectural aspects, and excessive use of hazard-resilient and more robust materials can reduce the overall sustainability of a green building.
Wednesday, July 27 11:00 - 12:30
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 685 2861 5551 Passcode: Mercon@T2
- 11:00 Utilization of Paddy Husk Carbon Black as an Alternative Filler Material in Rubber Industry
Paddy husk (rice husk) is an abundant agricultural waste product in Sri lanka. The utilization of paddy husk has been drawn widespread attention worldwide. In this study, the main focus is to produce carbon black from the paddy husk waste. The ability to use Paddy Husk Carbon Black (PHCB) as a substitute raw material for conventional carbon black has been investigated during the study by analyzing the physical and mechanical properties of the selected rubber compound. Based on the particle size of the ball milled PHCB powder, tyre inner liner compound was selected, and the compound formula was prepared for seven different ratios of PHCB and existing industrial carbon black type (N330). The rheological properties, tensile properties, tear resistance, bonding strength and age analysis were performed in order to find the best PHCB composition with the best properties. The sample containing 40% of PHCB and 60% N330 carbon black amount showed the optimum properties which satisfied the available industry specification limits and the properties of the reference sample. Hence, this is an effective way to reduce the filler cost of the rubber compound as well as it provides a sustainable solution for paddy husk waste management
- 11:15 A Novel Method on Fitting A Short Prony Series Using Creep or Stress Relaxation Data
The time dependent viscoelastic properties such as creep and stress relaxation are very important properties to be considered when designing with viscoelastic materials working at high temperature or extreme conditions. Mechanical models consisting of springs and dashpots are used to model these time dependent properties. Determining these models is done by fitting a Prony series to experimental creep or stress relaxation data. Most of the Finite Element Analysis software that are capable of viscoelastic modeling also uses Prony series to characterize such a material. Therefore, it is useful to have a fast, simple, and mathematically less cumbersome method to fit such a Prony series. The novel method introduced in this paper can be used to fit a short Prony series and makes the process much simpler and faster.
- 11:30 Evaluating the Thermal Conductivity of Three-Phase Insulation Composite Using Analytical and Numerical Methods
Sustainable insulation materials have been more attractive in the last two decades due to biodegradability, low embodied energy, availability, and non-toxicity. Those materials are primarily fabricated as composite materials using natural plant fibres. Then, the material contains three phases, i.e., fibre, binder, and air void. The volume fraction of each phase will decide the material's insulation properties and can be analysed using experimental, analytical, and numerical methods. Numerical and analytical methods are more attractive compared to experimental methods due to cost-effectiveness and less time consumption. However, only a limited number of studies have attempted to find the effective thermal conductivity (Keff) of a three-phase composite by these methods. In this study, the authors have suggested a plan to find the Keff of this composite using a numerical method and validated through the analytical techniques. This study, coir fibre was used as a fibre material and latex as a binder material. The results show that the numerical model should be changed based on the air void fraction. It was concluded that the close-pores structure model applies to the pore volume fraction of 0.65 and the open-pores structure model for pore fractions above 0.65 for numerical analysis.
- 11:45 Study of Degradation Behavior of ASA Coated PVC Roofing Sheets
PVC based roofing sheets are widely used in industrial and domestic applications today. It is widely recognized that ultraviolet rays (UV) in sunlight (wavelengths between 280 nm and 400 nm) cause photodegradation of some organic materials including polymers. Therefore, studying the change in properties of PVC/ASA roofing sheets due to weathering is essential for their successful application. From this study, it was attempted to study how photodegradation affects some properties like hardness and impact strength of the roofing sheet. It was evident from the UV exposure test data that prolonged exposure to UV radiation deteriorates the hardness and impact strength properties of the sheet. But no change in appearance was observed in both UV exposure test and accelerated weathering test.
- 12:00 The Effect of Surface Topology on the EDL Capacitance: 1_D Case
An electrical capacitor is an energy storage device that generates an electric field between electrodes and produces potential that can be channeled through associated circuits. The Electrical Double Layer (EDL) capacitor is a unique capacitor with a remarkably higher capacity. The energy densities of these capacitors can range between 0.5 and 10 Wh/kg. This study develops a method to predict the dependence of the double-layer capacitance on the roughness profile of the electrode using the linear Poisson-Boltzmann theory, and the Gouy-Chapman theory is discussed for 1-D systems. The roughness dependence of diffuse layer differential capacitance is obtained for a defined roughness profile. The theory developed here helps understand the Debye-length dependent on the roughness factor and profile. The variation of double-layer capacitance with roughness is analyzed based on a numerical solution obtained for the model roughness profile.
- 12:15 Modelling and Simulation of a Vertically Integrated Zinc Oxide Piezoelectric Nanogenerator
Due to recent developments in energy harvesting, there has been a subsequent rise in MEMS (Micro electromechanical systems) powered by low-frequency vibrations in the environment through effective transduction procedures like piezoelectricity. In this paper, a vertically integrated single piezoelectric Zinc Oxide nanowire-based system is modeled for energy harvesting applications. To reinforce this development, different structures of nanogenerators were modeled and simulated using COMSOL Multiphysics 5.3 software for their performance upgrades. It was developed to analyse the compression and bending effects of the nanowire. To compare and validate the induced piezoelectric output, mathematical equations were derived using piezoelectric constitutive equations. Moreover, the voltage output of the nanowire under constant lateral force was analyzed varying with the nanowire dimensions in terms of aspect ratio. The analysis results have shown that the compression of ZnO nanowire gives more output voltage compared to the bending of the nanowire for the same nanogenerator. The theoretical and simulation results also prove that the length of the nanowire does not influence the piezoelectric potential in a lateral bent nanowire.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 650 6157 4206 Passcode: Mercon@T3
- 11:00 A Theoretical Model to Analyze the Draft Force and Power Requirement of a Tillage Implement Consisting of Both a Disc Plough and a Subsoiler
The draft force and power requirements of tillage equipment are important metrics for agricultural equipment designers. Yet, a theoretical model to find these metrics for combined tillage equipment is lacking. To overcome the aforementioned limitation, this article presents a theoretical model to evaluate the draft force resulting from an implement consisting of both a disc plough and a subsoiler, and estimate the power requirement of dragging such an implement using a tractor. Existing models used to predict draft force for separate implements were incorporated herein to formulate the modified model. The model predictions are validated with discrete element method simulations. Additionally, the results show that implementation of a tandem tool configuration helps to reduce the draft force of the tool that follows the preceding tool in the sequence, albeit by a smaller amount (≈ 7-13%). Further modifications to the theoretical model are needed to generate more accurate results.
- 11:15 Development of a Numerical Model for Pollutant Dispersion over 3D Building Array
A CFD solver was developed by using OpenFOAM software to predict the pollutant's dispersion over a 3D building array. A simulation mesh setup was created to replicate an actual urban environment, where the dispersion phenomena at the pedestrian level is studied. Additionally, suitable model parameters were adapted to develop a transient solver to investigate the influence of obstacle array and turbulence over a built environment. The simulation results are then compared with the published experimental data to validate the overall model sensitivity and performance by analyzing the statistical parameters. Our simulation results show good agreement at the pedestrian level of exposure with a fraction of prediction for concentration within a factor of two observation FC2 is 85%. Also, the model results are well agreed when analyzing the statistical parameters such as fractional bias FB, Geometric mean bias MG, normalized mean square error NMSE and Geometric variance VG, which are 0.15, 1.17, 0.02, and 1.01 respectively. Moreover, the correlation coefficients R for horizontal concentration and velocity profiles are 0.83 and 0.91 respectively, which represent a strong model agreement. Therefore, this developed model can be used to predict the air pollution dispersion at the pedestrian level in the built environment
- 11:30 An Analytical Approach for Designing Turbo Expanders for Organic Rankine Cycle
ORCs (Organic Rankine Cycles) are becoming widely attractive for waste heat use since they facilitate power generation from low thermal content supplies. ORC may be optimized in a variety of ways after determining the appropriate operating working fluid and design parameters. This article introduces a new design approach to produce a turbo expander demonstrated for a 1kW ORC utilizing R245fa as the working fluid. The obtained initial dimensions of the rotor were evaluated using performance criteria commonly used in turbo-machinery designing and the best results were selected after conducting several iterations. The inlet tip speed is considered as the primary design variable since it is restricted by mechanical stress considerations. The results obtained from the rotor analytical study are then utilized for stator, volute, and diffuser designs
- 11:45 Heat Transfer Enhancement in Microchannels with Liquid - Liquid Slug Flow Using al2o3 Nanoparticles
Non-mixing two-phase flows in microchannels have become a popular technique for cooling applications due to their thermal performance and flow generation simplicity. Slug-flow is one of the regimes in two-phase flow that has higher rates of heat and mass transfer in microchannels compared to other types because of the internal fluid recirculation within the slugs. The addition of nanoparticles to one of the phases in slug-flow could further increase the heat transfer rates. Therefore, in this research, nanofluid-based liquid-liquid slug-flow was studied. Studies were carried out numerically using ANSYS Fluent®. A series of studies were carried out to investigate the effect of nanoparticles on heat transfer. Aluminium oxide (Al2O3) was selected as nanoparticles due to its physical-chemical stability along with its high thermal conductivity. Numerical results were validated with the experimental data available in the literature. Interface capturing of two-phase flow was done using VOF (Volume-of-Fluid) and Eulerian-Eulerian mixture models. The results showed a significant heat transfer enhancement when using nanoparticles in either phase. Two-phase slug-flow itself has shown up to four-times the increase in heat transfer in terms of Nusselt Number in the literature. This could be increased by more than eightfold by incorporating nanoparticles into the secondary phase.
- 12:00 Energy Efficiency Enhancement of Container Boxes Converted as Living Spaces (Convertainers)
The use of discarded shipping containers as temporary living spaces at construction sites, industrial facilities, and commercial applications, is progressively increasing due to several advantages such as mobility, cost effectiveness, lower construction time and reusability. These containers are called convertainers once they are converted into living spaces. Convertainers should be designed to improve the thermal comfort (to control the temperature and the humidity), indoor air quality and visual comfort (natural/artificial lighting) while minimizing the energy consumption by the facility. Buildings in hot and humid climates spend more than 60% of the total energy cost for Air Conditioning and Mechanical Ventilation to maintain the required thermal comfort of the occupants. Therefore, it is of utmost importance to analyze the heat flow to the convertainers and optimize the layout of the doors and windows to improve the natural lighting while reducing the heat gain to the convertainers. During this study, a mathematical model was developed to estimate the cooling load, to find an optimum insulation method, material, thickness and to optimize the layout to locate the window/s and door/s for a 20 ft convertainer to minimize the heat gain and cooling load.
- 12:15 Reducing the Excess Energy Consumption on Higher Ventilation Flowrates to Control the CO2 Levels of the Central Air Conditioning Systems in Polluted Urban Areas by CO2 Capturing
Controlling the air quality of the indoor environment is extremely important to improve the health and the productivity of the occupants. The air quality is maintained by providing ventilation air following the ASHRAE standards. The ventilation air (outdoor fresh air), usually process in the Air Handling Unit (AHU) of the Central AC system, and then deliver to the occupant zones. However, supplying outdoor air with increased levels of CO2 will adversely affect for the health and the productivity of the occupants. In the study, it was found that the CO2 levels in the indoor environment increase with the increased atmospheric CO2 levels and the recirculation air percentage. When the CO2 level of the outdoor air is higher, IAQ can only be controlled by supplying more fresh air to the indoor environment. However, it increases the load on the Cooling Coil and eventually, electricity consumption of the chiller increases. Moreover, the higher excess air flowrates of the MVAC systems require larger fans and increased equipment costs. Therefore, it has been suggested that a CO2 capturing Device suitable for MVAC systems can handle these extreme scenarios and reduce the operating and maintenance cost of the MVAC systems.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 680 2195 3591 Passcode: Mercon@T4
- 11:00 Enhanced Time Delay Neural Network Architectures for Sinhala Speech Recognition
Automatic Speech Recognition (ASR) has become a fast-growing research domain due to advancements in Machine Learning. In addition to the development of large training corpora, the introduction of novel architectures for ASR models has contributed to defining new boundaries for the performance of speech recognition systems. However, there is a significant difference in speech recognition accuracy between major world languages and low-resourced languages such as Sinhala, due to inadequate research. We have applied enhanced time-delay neural network architectures for acoustic modeling in Sinhala ASR, including the Multistream CNN architecture. Using the Kaldi ASR Toolkit, we have trained ASR models with a publicly available corpus of over 200 hours of speech data. The results show a remarkable improvement in the accuracy of Sinhala speech recognition as demonstrated by a reduction in the Word-Error-Rate (WER) to 25.12%.
- 11:15 MetaPCbin: Plasmid/Chromosome Classification for Metagenomic Contigs Using Machine Learning Techniques
Chromosomes and plasmids are the major carriers of genetic material in microorganisms such as bacteria. Separating chromosomal and plasmid DNA from large datasets is important as plasmids and chromosomes affect functions and other environmental adaptations. Bioinformatics methodologies have been developed for plasmid classification with the advancements in sequencing technologies. The usage of normalized short k-mer counts with machine learning models has been popular in the characterization of plasmids and chromosomes. Furthermore, bio-markers from DNA sequences as features have also been studied in plasmid classification. However, both approaches suffer from the trade-off between precision and recall. MetaPCbin is a plasmid detection tool that combines computational and genetic approaches into a hybrid method of plasmid prediction. MetaPCbin uses an artificial neural network that uses k-mer counts as features and a random forest model that uses bio-markers. MetaPCbin evaluates the precision and the recall of the classification of real-world DNA sequences from the RefSeq database and simulated sequences. The results show that it is capable of performing plasmid classification while maintaining high precision and recall compared to the state of the art. MetaPCbin is freely available at: https://github.com/MetaGSC/MetaPCbin
- 11:30 Segmentation and Significance of Herniation Measurement Using Lumbar Inter-Vertebral Discs from the Axial View
According to statistics, more than 60% of people suffer lower back pain at a certain time in their lives. Disc hernias are the most common cause of lower back pain, and the lumbar spine is responsible for more than 95% of all herniated discs. Generally, radiologists study the MRI during the clinical phase to detect a disc hernia. There could be several cases to evaluate, leaving the doctors to cogitate and envisage. Medical image segmentation aids in the diagnosis of spinal pathology, studying the anatomical structures, surgical procedures, and the evaluation of various treatments. However, manual segmentation of medical images necessitates a significant amount of time, effort, and discipline on the part of domain experts. This research study describes a framework that automates the segmentation of lumbar intervertebral discs using MRI images. Through this system, we can detect minor changes at the pixel level that are impossible to identify with the naked eye. We used convolutional neural networks with the UNet architecture to achieve the semantic segmentation process. The segmentations were evaluated using the Jacquard index and the dice coefficient.
- 11:45 Aspect Detection in Sportswear Apparel Reviews for Opinion Mining
Manufacturers and brand owners apply sentiment analysis techniques on customer reviews to identify customer opinions on their products and services. Sentiment analysis at the document level or sentence level does not provide a complete view of the customer opinion because customers may express their opinion on different aspects of the product or service within a single review. This issue has inspired aspect-level opinion mining. Two core tasks are involved with aspect-level opinion mining: aspect detection and aspect-based sentiment analysis. This research is aimed at the first task - aspect detection. The focused domain is sportswear apparel, which has been largely overlooked in the field of opinion mining. Accordingly, this paper presents a new dataset produced with manual annotations by domain experts, according to a newly defined aspect taxonomy. This research compares the performance of a set of pre-trained language models for the considered task, and achieves state-of-the-art performance for sportswear apparel reviews using a novel ensemble method.
- 12:00 Erroff: A Tool to Identify and Correct Real-Word Errors in Sinhala Documents
Sinhala is a low-resource Indo-Aryan language used by approximately 16 million people, mainly in Sri Lanka. Because of the complexity of the Sinhala language, detection of spelling errors is not so easy. A real-word error happens when a word is in the vocabulary but is not valid in the context in which it appears. Checking for real-word errors in a sentence is more difficult than checking for non-word errors, which are not in the vocabulary. We present the implementation of a neural-network based system for identifying real-word errors and non-word errors in Sinhala. We prepared a candidate list of real-word errors. Further, we have selected a suitable model and trained it using several different datasets. Thus, this paper sets a new baseline for the detection and correction of real-word errors in Sinhala documents. Our product, source code, candidate error list, training datasets, and evaluation dataset are publicly released.
- 12:15 Language Model-Based Spell-Checker for Sri Lankan Names and Addresses
Names are used abundantly in various applications, but traditional spell-checkers are not adapted to correcting errors in named entities. In this research, we suggest a spell-checker for Sri Lankan names and addresses. The main challenge in building a spell checker for named entities is the inability to create a comprehensive dictionary. Our spell-checker overcomes this challenge by utilizing a language model for evaluating the validity of named entities and a non-Dictionary suggestion generator. The resulting spell-checker boasts performance of up to 96% suggestion adequacy. This spell-checker can be used in applications directly, and the components built can be repurposed for other named entity-related research.
Wednesday, July 27 13:30 - 15:00
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 613 4160 9422 Passcode: Mercon@T1
- 13:30 3D Full-Field Deformation Measurement Using Stereo Vision
Measuring 3D deformation and strain are crucial parameters in structural engineering applications both at the construction and operational stages. Precise 3D full-field measurements are useful in structural optimization, damage detection and retrofitting. Digital Image Correlation is a non-contact optic-based measurement technique that is proven to be an ideal candidate in this regard. It has the potential to become a cheap, simple, and precise solution for deformation measurement. However, the currently available Digital Image Correlation measuring systems require expensive dedicated software packages and physical resources which are difficult to access. Therefore, there is a need to develop a cost-effective measuring technique to effectively use it in the local context. This research focuses on the development and validation of a precise non-contact-based deformation measurement technique. In the proposed method, 3D full-field deformation of the deforming object is measured by processing stereo photographs taken with commonly available digital cameras using the image processing toolbox available in the MATLAB commercial package. Further, the proposed method is enhanced by developing it as a standalone application, which can be installed and conveniently used by any technician. Capability of using the developed application in common civil engineering laboratory experiments has been demonstrated.
- 13:45 Case Studies on Blast Behaviour of Glass Façades: Sri Lanka Easter Bombings
Sri Lanka Easter attacks were done by coordinated suicide bombers on 21st of April, 2019. This paper investigates the damages to the glass façades due to the explosions that occurred inside the five-star hotels, Shangri-La, and Kingsbury in central Colombo. It is evident from previous explosions that the blast-related injuries are mainly caused by the free-flying glass fragments. Laminated Glass (LG) will provide better resistance to explosions that occur outside the building if they are properly designed to be held on the supporting structure. Because, if the blast pressure enters the building, it will cause severe damage to the building elements while creating injuries to the occupants. However, when an explosion occurs inside the building, damage to the building elements and occupants will be severe if the blast pressure cannot escape from the confined building premises easily. Therefore, both of these aspects should be considered when designing glass façades for a credible blast load. LG has better blast resistance than monolithic glass. This paper presents a comprehensive review on the effect of the Easter bombings on glass façades and some design strategies which can be recommended for blast-resistant glazing with the evidence from available literature and design standards.
- 14:00 Design Optimization of a Steel Bridge Bracket
Steel brackets have a renowned potential of being used in bridge constructions as a load-bearing element. However, the excessive material usage in bracket manufacturing will lead to expensive constructions, increased energy consumption and a rise in carbon footprint. To circumvent these challenges, this paper demonstrates a novel approach for producing an optimum and sustainable steel bracket for pedestrian bridge construction. Topology optimization is used as the tool of choice in this work, which has a proven record of arriving at the highest stiffness to weight ratio. This study uses an existing steel bridge bracket in Castleford Foot Bridge, England as a study case. The bracket is optimized under several volume fractions and ultimately, the optimum design is selected based on both simulation results and practical considerations. It is shown that a considerable amount of material could be saved without sacrificing the strength and stiffness requirement of the bridge bracket. Without a loss of generality, the selected optimal design is manually extracted to a Computer-Aided Design (CAD) software for further post-processing and analysis.
- 14:15 Study on Honeycombs in Structural Concrete Elements
Concrete structures are subjected to various types of surface defects such as honeycombs, surface voids, form streaking, etc. Proper understanding of the root causes of each type of defect is significant in preventing recurrence as well as applying remedies. An extensive field survey was conducted in connection with the construction sector of Sri Lanka to gather information on the current practices. It was found that the construction industry needs more awareness on correct practices. This study attempts to fill the gap between current field practices and standard practices. Poor workmanship in consolidation of fresh concrete leads to most of the defects, but this study shows how the understanding of technical background of each activity and the proper planning at initial stages contribute to effortless improvements in workmanship. Contradictions between codes of practices for design of reinforced concrete and codes of practices for consolidation of concrete were taken into consideration under this study. In order to identify the locations of hidden honeycombs, a series of UPV tests (conventional approach) were performed, quantitative and qualitative analysis of them has been provided under this study. It has shown the importance of moving to modern non-destructive evaluation approaches for such scenarios.
- 14:30 Investigation of the Feasibility of Pre-Stressed Concrete (PC) over Conventional Reinforced Concrete (RC) in Water Retaining Structures
Concrete water tanks are used to store and supply safe drinking water and are designed as crack-free structures. The demand for water tanks will continue to increase in the coming years; quick construction methods and economical design approaches will be helpful in the selection of water tanks for relevant applications. Pre-stressed Concrete (PC) will be a better alternative for Reinforced Concrete (RC) water tanks which are commonly used in Sri Lanka. This paper presents design guidance for PC circular water tanks resting on the ground. The design and construction approaches for PC circular water tanks were identified following EN 1992-1-1:2004 and EN 1992-3:2006 standards. The Midas FEA Finite Element (FE) software was used to analyse the tanks. The economic feasibility of both PC and RC tanks is compared for different tank capacities. The design outputs were converted into structural drawings and bills of quantities. Results of the material take-offs showed that RC is economical only for 4500m3 or less capacity. For higher capacities (above 4500 m3), PC tanks become cheaper by around 12-14%. The information presented in this paper will be helpful to understand the design philosophy for the safe and economical design of water tanks with better crack control.
- 14:45 Homogenization of Ultra Thin Woven Composite Structures at High Curvatures
Growing demand for ultra-thin woven composites has been identified in weight-sensitive applications, especially in space engineering applications such as self-deployable structures. They undergo extreme curvatures during folding and deployment process and hence understanding their mechanical behaviour is important for optimization of future structures. Literature on experimental studies unfolds that there is a considerable reduction in bending stiffness of these ultra-thin woven composites when subjected to curvatures. This paper presents a numerical investigation that incorporates inter-tow and inter-lamina interaction behaviour on the homogenized response of a two-ply plain woven carbon fibre composite. Two distinct models were used in the analysis with dry fibre approach and resin embedded geometry. The analysis is advanced further towards the non-linear regime to predict the response under higher curvatures. It is shown that the developed models are capable of capturing the reduction in flexural stiffness.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 685 2861 5551 Passcode: Mercon@T2
- 13:30 Mie-Theory-Based Investigation of the Effect of Size Distribution on the Surface Plasmon Absorption of Silver Nanoparticles
The surface plasmon absorption of metallic nanoparticles is of great interest due to their wide range of applications, predominantly with optical technology. A reliable plasmon spectrum analysis tool would be of great value to the researchers working in this area. Mie theory-based theoretically computed spectrum generating tools are used in the literature to analyze the surface plasmon absorption of monodisperse particles. However, none of them can accommodate size distribution contributions. As monodisperse nanoparticle dispersions are practically impossible to synthesize, incorporating the particle size distribution effect into the surface plasmon absorption spectrum analysis tools makes them more reliable. In this study, we investigated the effect of particle size distribution on the surface plasmon absorption bands of silver nanoparticles suspended in water. Mie theory-based simulations were performed for various particle sizes ranging from 1 to 40 nm and for different size distributions. The maximum absorbance, peak position, and full width at half maximum (FWHM) variations with respect to particle radius were analyzed.
- 13:45 Effect of Nano-Silver Ions Pumps on Antimicrobial Activity of AgNps Incorporated Polymer-Based Food Packings
Use of AgNp (silver nanoparticle) incorporated polymer films for industrial applications requires an essential understanding of the variations of antimicrobial strength according to the dispersion parameters. This study was carried out to investigate the particle size effect on the antimicrobial potency of AgNp incorporated polymer films and to observe the antimicrobial activity of silver nanoparticle impregnated polymers due to the ion pumping ability of nanoparticles in to the medium. Experimental observations were analyzed based on the theoretical frameworks developed in the literature. The paper also provides the fundamental theoretical framework for practicing engineers to design products based on these materials. This enables the industrial applications of these types of materials.
- 14:00 Direct Current Resistivity Based In-Situ Cure Monitoring Technique for Amine Cured Epoxy Resins
The Epoxy resins and epoxy resins-based system usage in industrial applications such as composites and electronic materials keep growing. Thus, research focused on enhancing the properties of these resin-based systems is of importance for manufacturing quality controls. Especially monitoring of cure progression and chemo-rheological behavior of epoxy resins are essential for many industries. Commonly practiced cure monitoring methods such as DSC and DMA for the purpose are conducted in laboratories under specified conditions and are not practiced for real-time cure monitoring. However, in-situ cure monitoring techniques are essential for many industries as they provide more insight and thus more control over processing parameters. This study introduces a direct current resistivity-based cure monitoring method as it is simple, cost-effective, reliable, and more importantly, industry-friendly. The fast response of direct current measurements combined with the simplicity of the analysis makes this method suitable for real-time sensing applications. The strong correlation between the degree of cure and the viscosity allows us to take simultaneous measurements of both. The method's feasibility was analyzed using two amine cured epoxy resin systems.
- 14:15 Modeling and Validation of Nanoparticle Formation in Wet Chemical Synthesis of Nanohydroxyapatite
The wet chemical synthesis of Nano-Hydroxyapatite HAP [Ca10(PO4)6(OH)2] derived from precursors Ca(OH)2 and H3PO4 was experimented using a kinetic model derived based on the classical nucleation theory. The model gives a mathematical formulation for the nucleation rate in terms of the process variables of the wet chemical synthesis namely supersaturation, temperature, and interfacial tension. Only the effect of supersaturation for nano formation was studied in the experimental work of this study. The different supersaturations for five different samples were initiated by changing the precursor concentrations keeping the Ca/P molar ratio at 1.6 to 1.7 in the solution being mixed. Finally, the model was statistically and experimentally validated using Fourier Transform Infrared Spectroscopy (FTIR) analysis, and data obtained by laser particle analyzer. This model can be potentially used to synthesize Nano-Hydroxyapatite particles in a quantitative manner changing the supersaturation of the wet medium by precursor concentrations.
- 14:30 Effects of Kaolin with High Silica Content on Properties of Ceramic Tiles
In general, Quartz, Feldspar, Ball Clay, and Dolomite are the main raw materials used in the tile industry. The availability of quality Ball Clay for the tile manufacturing industry has decreased over the years in Sri Lanka and the tile industry intends to substitute ball clay with another suitable clay. In this study, the New Kaolin source was investigated for the tile industry as the main clay mineral with Feldspar, Dolomite, and Bentonite Clay. Initially, new Kaolin clay was characterized using X-ray diffraction, wet chemical analysis, and differential thermal analysis. It consists of 56.78% of Silica. The body mix of the tiles was prepared and the Particle size distribution of the body mix was determined. The shape of the tiles was obtained using a powder pressing method. Samples were dried in an oven and fired in a muffle furnace at 1100oC, 1150oC, 1180oC, and 1200oC. Relationships between the physical properties of the fired tiles have been established. The improved physical properties of tiles at the firing temperature of 1200 0C complied with ISO 13006 standard. Based on this study, M2 Kaolin can be strongly recommended as a highly appropriate clay material for the ceramic tiles manufacturing industry in Sri Lanka.
- 14:45 Potential of Chalcogenide Halide Bismuth CH3NH3BiChI2 (Ch = S, Se,) as Solar Absorbers Based on Theoretical Study
Organo lead halide perovskite has received a great deal of attention in the past couple of years due to its excellent optoelectronic properties. However, the presence of toxic lead in these materials is a significant concern for human health. Therefore, it is essential to select the elements for solar cell design that are environmentally friendly and conducive to human health. Bismuth-based perovskite has become a promising alternative due to similar photovoltaic properties and enhanced environmental stability. Bismuth ternary based halide has interected due to their superior stability, but the main disadvantage is their wide band gap for single junction solar cells. The incorporation of the chalcogenide anions into bismuth chalcogenides was reported to have smaller bandgaps than that of the halide bismuth perovskites, which could reduce their bandgaps without affecting their photovoltaic properties. As a result, for photovoltaic applications, the structural and band gap properties of mixed chalcogen and halogen anions, CH3NH3Bi(Ch, X)3 (Ch = chalcogen; X = halogen), were calculated using a combination of density-functional theory calculations. Results reveal that the band gaps of CH3NH3BiI2S and CH3NH3BiI2Se are 1.39 eV and 1.34 eV, which are in the range of band gaps required for photovoltaics.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 650 6157 4206 Passcode: Mercon@T3
- 13:30 Design and Development of an Automated Paddy Transplanting Machine with a Novel Planting Mechanism
Paddy planting in Sri Lanka has a deficit in mechanization. The commercially available transplanters are mainly for the rice mat method and are less suited for the short-term rice varieties planted in Sri Lanka due to the high transplanting shock. The study aims to introduce an automated paddy transplanting machine that eliminates transplanting shock. The study focuses on the rice pot seedling planting method, and a novel venturi-based vacuum ejection mechanism for the planting was developed. The planting mechanism was optimized through CFD to improve the ejection pressure. A nursery tray conveying mechanism was developed to feed the seedlings to the planting mechanism, along with a modified nursery tray design. A PLC-based control system was developed to control the planting and nursery tray conveying mechanisms. The final system was field-tested with paddy seedlings ejection with a success rate of 92.8%.
- 13:45 A Computational Study of the Aerodynamics of Plunging and Pitching Motions of Airfoils
Investigation of flow characteristics and force generation of flapping wings have received significant attention in modern fluid dynamics due to emerging applications like bio-inspired Micro Air Vehicles (MAVs) and energy harvesters. In this study, aerodynamic characteristics of NACA 2412 airfoil in plunging and pitching motion are simulated using an incompressible Navier Stokes solver in varying Reynolds and Strouhal numbers. The wake of the airfoil which is visualized using velocity and pressure contour plots and aerodynamic force generation are analyzed. A close agreement is obtained between numerically simulated aerodynamic characteristics including wake structure and forces in this study and experimental results in the literature. The analysis discloses that wing-wake interaction enables a dramatic increment in trust and lift forces up to 300%. Moreover, aerodynamic forces generated in combined pitching and plunging motion show a maximum of 225% increment from the numerical sum of forces in the two sub-motion in some combinations of Reynolds and Strouhal numbers, demonstrating the coupled behaviour of plunging and pitching motions.
- 14:00 Numerical Investigation to Improve the Performance of Induction Heating Oven for Tyre Mould Preheating
This paper presents a numerical analysis of an industrial-scale induction heating oven to improve heat transfer performance for applications in the tyre manufacturing industry. Tyre mould preheating is a vital step in the tyre manufacturing process, for which the local industry is currently using conventional heating techniques. Research has shown that induction heating has the potential to significantly reduce the heating time and the energy use of the tyre mould preheating. However, some limitations in obtaining the required temperature profiles have prevented the local industry in moving toward induction heating. Hence, this research focused on using finite element analysis to study the induction heating process to propose an improved oven unit for tyre mould preheating. The simulation was conducted on a simplified and scaled-down model of a tyre mould to study the effects of key parameters. The simulation results showed that. The pancake type coils are recommended for the application and the maximum Ohmic losses could be obtained when the coil air gap is 7-8 mm.
- 14:15 Diagnosing Localized and Distributed Faults of Rolling Bearing Using Kurstogram and Machine Learning Algorithms Using Bearings Audio Signal in Comparison with Vibration Signal
Condition monitoring of rolling bearing using bearing's audio signal and vibration signal via cost-effective accelerometer is experimented with and analyzed for both localized faults and distributed/ generalized roughness faults. Even though the Fast Fourier Transform (FFT) of the bearing's audio signal is not appropriate to diagnose bearing faults under varying background noises it was possible to observe characteristic frequency hikes related to misalignment from the FFT of the vibration signal. Localized faults are processed using Kurstogram, and Hilbert transform. Misalignment experiments for different types of bearings at different speeds and related fault frequencies are identified through both bearing audio signal and vibration signal. Artificial Neural Network (ANN) and Convolutional Neural Network (CNN) are trained using the Mel Frequency Cepstral Coefficient (MFCC) feature of bearing audio signals with various background noises and/or the FFT of the vibration signal to distinguish between healthy bearing and bearing having distributed /generalized roughness faults. The ANN and CNN models trained using fused MFCC of bearing audio signal and FFT of the vibration signal yield greater accuracy than that of models trained using MFCC of the audio signal or trained using FFT of the vibration signal
- 14:30 Effects of Restricting Ankle Joint Motions on Muscle Activity: Preliminary Investigation with an Unpowered Exoskeleton
The human ankle comprises multiple joints and supports triplanar motions to allow the foot to pronate or supinate during walking. However, ankle exoskeletons are mainly designed to assist propulsion whilst inhibiting other degrees of freedom. The kinematic constraints posed by the simplified joint mechanisms may negatively affect the wearer's performance. In that context, this paper presents a preliminary investigation on the effects of restraining ankle motions during level walking with an unpowered ankle exoskeleton having compatible joint axes. The work investigated the changes in muscle activity in the lower limbs under various constraining conditions. A healthy male subject took part in five tests involving different combinations of kinematic restrictions of the ankle. The electrical activities of key muscles were recorded using a surface electromyography measurement system. The root-mean-square feature of signals was used for comparing results. The analysis confirms that constraining non-sagittal plane motions has caused significant changes to the activities of muscles. The investigation reveals the relative importance of developing ankle mechanisms that promote higher kinematic compliance. In the future, further studies should be conducted to reaffirm the statistical significance of muscle activity across multiple test subjects and assess human comfort to derive specific design guidelines for ankle devices.
- 14:45 Design and Analysis of an Aerodynamic Structure for a Ground and Aerial Vehicle
This paper proposes a novel hybrid approach for ground and aerial locomotion. Conceptual designs have been created for ground and aerial platforms and analyzed them separately. 3D models are optimized considering the practicality and ease of manufacturing. Mecanum wheels have been integrated with the ground platform to enable multidirectional locomotion. Thrust vector system has been added to quad rotor aerial platform to increase the forward propulsion. Mathematical models are generated and simulated to visualize the motion virtually and to derive torque requirement to select suitable actuator components. FEA (Finite Element Analysis) analysis proved the proposed platform can withstand the predefined load conditions (10kg) with a good safety factor of 5.9. Combined platforms have been subjected to CFD (Computational Fluid Dynamics) analysis and it has been proved that platform lift force is significantly increased (by 3.5N) compared to traditional quad rotor configuration due to the aerodynamic body.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 680 2195 3591 Passcode: Mercon@T4
- 13:30 Low Resource Multi-ASR Speech Command Recognition
There are several applications when comes to spoken language understanding (SLU) such as topic identification and intent detection. One of the primary underlying components used in SLU studies are ASR (Automatic Speech Recognition). In recent years we have seen a major improvement in the ASR system to recognize spoken utterances. But it is still a challenging task for low resource languages as it requires 100's hours of audio input to train an ASR model. To overcome this issue recent studies have used transfer learning techniques. However, the errors produced by the ASR models significantly affect the downstream natural language understanding (NLU) models used for intent or topic identification. In this work, we have proposed a multi-ASR setup to overcome this issue. We have shown that combining outputs from multiple ASR models can significantly increase the accuracy of low-resource speech-command transfer-learning tasks than using the output from a single ASR model. We have come up with CNN based setups that can utilize outputs from pre-trained ASR models such as DeepSpeech2 and Wav2Vec 2.0. The experiment result shows an 8\% increase in accuracy over the current state-of-the-art low resource speech-command phoneme-based speech intent classification methodology.
- 13:45 Adversarial Learning to Improve Question Image Embedding in Medical Visual Question Answering
Visual Question Answering (VQA) is a computer vision task in which a system produces an accurate answer to a given image and a question that is relevant to the image. Medical VQA can be considered as a sub field of general VQA, which focuses on images and questions in the medical domain. The VQA model's most crucial task is to learn the question-image joint representation to reflect the information related to the correct answer. Medical VQA remains a difficult task due to the ineffectiveness of question-image embeddings, despite recent research on general VQA models finding significant progress. To address this problem, we propose a new method for training VQA models that utilize adversarial learning to improve the question-image embedding and illustrate how those embedding can be used as the ideal embedding for answer inference. For adversarial learning, we use two embedding generators (question-image embedding and a question-answer embedding generator) and a discriminator to differentiate the two embeddings. The question-answer embedding is used as the ideal embedding and the question-image embedding is improved in reference to that. The experiment results indicate that pre-training the question-image embedding generation module using adversarial learning improves overall performance, implying the effectiveness of the proposed method.
- 14:00 Enhanced Feature Aggregation for Deep Neural Network Based Speaker Embedding
This paper proposes a new feature aggregation mechanism for deep neural network based speaker embedding for text-independent speaker verification. In speaker verification models, frame-level features are fed into the pooling layer or the feature aggregation component to obtain fixed-length utterance-level features. Our method utilizes the correlation between frame-level features such that dependencies between speaker discriminative information are represented with weights and produces weighted mean features with fixed-length as output. Our pooling mechanism is applied to the ECAPA-TDNN baseline architecture. In comparison to the Attentive Statistics Pooling applied to the same baseline, training on VoxCeleb1-dev dataset and an evaluation on the VoxCeleb1-test dataset shows that it reduces equal error rate (EER) by 7.32% and minimum normalized detection cost function (MinDCF) by 7.34%.
- 14:15 MetaGraph: Plasmid/Chromosome Classification Enhancement Using Graph Neural Networks
Chromosomes and plasmids are the main sites of genetic information in microorganisms. Separately identifying plasmids and chromosomes is essential for further metagenomic analysis. Computational tools have achieved significant results in classifying DNA into plasmids and chromosomes. However, there is often a trade-off between recall and precision in the currently available tools. Several graph-based tools have been proposed to improve the prediction precision and recall simultaneously by improving upon the results produced by existing tools. We propose MetaGraph, a Graph Neural Network (GNN) based tool for plasmid/chromosome classification enhancement. It uses the high confidence predictions of existing plasmid/chromosome prediction tools and improves the prediction accuracy of low confidence predictions using plasmid probabilities as features for the GNN. We evaluated MetaGraph for a set of simulated DNA sequences. The results significantly improved over state-of-the-art tools like PlasFlow and PlasClass. The results were increased up to 20\% from the initial PlasClass predictions. The source code for MetaGraph is freely available at: https://github.com/MetaGSC/MetaGraph
- 14:30 Domain Specific Named Entity Recognition in Tamil
This paper presents a Tamil Named Entity Recognizer for history domain. The system uses a manually annotated corpus of 23k tokens and the dataset is tagged with 36 tags related to history domain. The Named Entity Recognition (NER) model is trained for Tamil using Conditional Random Fields (CRF) classifier with the use of features extracted based on the domain of interest and language. Hyper parameter tuning is applied with random search algorithm to find the best hyper parameters for the model. Tamil is a low resourced and morphologically rich language which makes the task challenging. Despite that, the system achieved a fair results with a micro-averaged Precision, Recall and F1-score of 87.9%, 67.1% and 76.1% respectively.
Wednesday, July 27 15:30 - 17:00
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 613 4160 9422 Passcode: Mercon@T1
- T1-1-3.1 15:30 A Comparative Study to Evaluate the Effectiveness of Different Structural Forms for Medium-Rise Apartment Buildings
The rapid urban migration and the infrequency of spaces in mega cities have become a challenge for all most all countries. To fulfill the housing requirements of the ever-growing population with the scarcity of valuable lands, the best solution is to come up with high-rise or medium-rise apartment buildings. Even though there are different structural forms that can be incorporated into high-rise apartment structures, most of the time structural designers select based on their experience and approach which are not effective all the time. The structural design for a given structure should be optimum in terms of structural performance and associated costs. Since wind and seismic forces govern the design of high-rise structures, those lateral forces are significant to be studied. So, this analytical study was carried out to evaluate the effectiveness of six different structural systems of 20-story RC (Reinforced Concrete) structures under the effect of wind and seismic loading including a moment-resisting frame as the base model, four wall frame structures and a frame-tube structure. Models are compared based on the parameters such as maximum top storey displacement, inter-storey drift ratios, member forces and moments utilization, seismic induced base shear and human perception levels of lateral acceleration.
- T1-1-3.2 15:48 Study on Concrete-Filled Double-Skin Circular Steel Tubes Under Axial Compression
In this research, an attempt has been made to evaluate the performance of concrete-filled double-skin circular steel tubes (CFDSCT) under axial compression and their application in buildings in terms of performance. Concrete-filled double-skin steel tube (CFDST) is a composite construction component. It consists of two steel layers with concrete sandwiched in between the tubes. The inner hollow steel section acts as formwork and reinforcement for the concrete. CFDST has numerous advantages, which include high strength, high bending stiffness, and good seismic and fire performance. Moreover, this type of structural member is not being used largely in construction, hence it's vital to investigate and obtain a clear analysis of the implementations. This study presents a detailed investigation of how CFDSCT columns behave under axial compression, by experimenting and further verifying it through analysis of the structural component by developing a numerical model using "ABAQUS '' finite element software. The experimental results were further compared to theoretical calculations performed using the "Eurocode 4" design standard. The simulation and the theoretical data are in good compliance with the test results. Ultimately, using a numerical model developed with SAP2000 software, this study discusses the feasibility of using CFDST columns in buildings in seismic performance.
- T1-1-3.3 16:06 Rapid Risk Assessment of Sri Lankan School Buildings Against Tsunamis
Rapid assessment of building vulnerability and risk is very useful, especially if based on sound engineering principles as opposed to expert opinion alone. A tsunami relative risk index (TRRI) has recently been proposed for hospital buildings based on such an approach. This study extends the concept to reinforced concrete school buildings. Two typical type plans of school buildings were explored, each of two and three storey height. The criterion for overall structural failure was the shear capacity of columns; for scour, the number of footings undermined; and for debris impact, the shear capacity of corner columns. Of the parameters explored, the inundation depth and flow velocity were found to have the greatest influence on TRRI, while building type, building height and flow direction had much smaller influence. Debris impact was the governing risk at low inundation depths (around 1m), with scour at medium depths (around 3m) and overall structural shear failure at higher depths (around 5m).
- T1-1-3.4 16:24 Investigation of Using Non-Homogeneous Rubber Aggregate in Modified Concrete Mix Design
This article investigates the impact of using non-homogenous rubber aggregate on a developed concrete mix design. Identifying the dominant reasons and modifications to be made to improve the properties of rubberized concrete are discussed with respect to the diverse number of literatures. The recycled waste tire rubber particles were tested to identify the physical properties of rubber aggregate and twelve rubberized concrete cubes were tested in axial compression. The cubes were produced by replacing waste tire rubber with 1) 0% aggregate volume (Series 1) 2) 20% fine aggregate volume (Series 2) and 3) 10% coarse and 10% fine aggregates of the total aggregate volume (Series 3). The results show a high-water absorption rate of 6-7% in rubber aggregate. The compressive strength of cubes reached up to 48.6 MPa, 32.4 MPa, and 37.5 MPa in Series 1, 2, and 3, respectively. Implementing 10% coarse and 10% fine rubber aggregate enhanced the compressive strength by 10.5%. There is clear evidence on improved mechanical properties of rubberized concrete with the addition of non-homogenous rubber aggregates.
- T1-1-3.5 16:42 The Use of Plastic Aggregate in Concrete
Plastic waste management is a growing concern worldwide since permanent solutions are costly for third-world countries. This study explores storing plastic waste in concrete as a partial replacement of the fine aggregate to produce a useful building material. To resolve the material's lack of compressive strength, this study used HDPE chemically treated with Sodium Hypochlorite (NaOCl) and partially replaced the cement with silica fume at 7.5%, and 10% to improve the concretes Interfacial Transition Zones (ITZ). This research tests the workability, density, compressive strength, and completes a microstructure analysis of this material to determine if structural lightweight concrete (SLWC) can be produced. The results obtained indicate that adding silica fume with chemically treated aggregate increased the compressive strength by 1.9% and 7.4% respectively in comparison to the control. Through the statistical analysis, these additions were then shown to make a significant difference in the concrete's strength. The microstructure analysis too confirmed that the quality of the ITZs had improved in these mixtures. However, the workability of these 2 mixtures was reduced by 77.4%. The study concludes that although the concrete isn't lightweight, its compressive strength can be improved to match that of conventional structural concrete.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 685 2861 5551 Passcode: Mercon@T2
- 15:30 Synthesis of Calcium Oxide Nanoparticles from Waste Eggshells
Calcium oxide nanoparticles were synthesized from waste eggshells through a process of combination of ball milling and calcination. Utilizing waste eggshells as the precursor and using ball milling a sustainable, cheap and convenient process makes this experiment sustainable. The eggshells are characterized by SEM, TGA, FTIR and XRD and the calcined eggshell powder is characterized by SEM and FTIR. From this study, the synthesis of CaO nanoparticles, observing the temperature effect on calcined eggshell powder are observed and applying CaO nanoparticles in seed priming are expected.
- 15:45 Modeling the Mechanical Behavior of Microcrystalline Cellulose-Based Polymer Composite Materials
Polymer-based composite materials are used in many engineering applications. There is an increasing demand for environment-friendly reinforcing materials in the industry. Previous studies done in this laboratory suggested that microcrystalline cellulose-based composite has better properties such as tensile strength, elastic modulus, stiffness, water absorption, and thermal stability. The property optimization solely through an experimental approach costs a lot of time and resources. However, if a reliable model can be developed to explain the composition property relationship, the cost can be significantly reduced. A simple rule of mixture-based models does not adequately explain the variation of mechanical properties with the composition. This paper discusses a modified form of a mathematical model based on a rule of mixture principles to predict the mechanical behavior of microcrystalline cellulose-based polymer composites. The model aims to predict the mechanical property variation of Microcrystalline cellulose (MCC) reinforced composites. Theoretical values obtained from the developed model were compared with the experimental values obtained from the fabricated composites. The results show good agreements, confirming the potential of the mathematical model.
- 16:00 Study on Thermal Endurance of Plasticizer in Locally Manufactured Electrical Cable Insulation
Electrical cables are collections of one or more electrical conductors which are separately insulated and covered together using a sheathing material. Since air does not perform well as a good insulation material, an insulation material is also introduced to resist the passing of electrical current in the radial direction. This will prevent electrical leakage and protect the stability of wire material by concealing it from environmental attacks such as heat and humidity. This paper analyzes the kinetics of the thermal endurance of plasticizers present in locally available electrical cable insulations. For this purpose, a model was developed to map higher temperature accelerated plasticizer evaporation kinetics to lower temperature practically experiencing values. Plasticizer evaporation data were collected in the range of 80 - 160 ˚C. Since the plasticizer evaporation reaction occurs over the considered temperature range, notable physical transitions (e.g., crystallization or glass transition) were not observed within the mentioned temperature range. Therefore, The Arrhenius-principle-based approach was employed to map accelerated condition measurements to ambient condition evaporation. An Experimentally determined evaporation behavior was used to define the evaporation kinetics of plasticizers. It was observed that the rate constant of plasticizer evaporation increases with the increasing temperature.
- 16:15 Synthesis & Utilization of Rice Husk Carbon Black (RHCB) for Rubber Compounding
This study describes a procedure in which a compound has been formed by pyrolysing rice husk at high temperature and subsequent grinding, which is intended to be used as a substitutional filler for carbon black in natural rubber compounds. This process has been investigated in order to develop a better value addition for rice husk which is a material source that is abundantly available in rice cultivating countries including Sri Lanka. The study has investigated effects on rheological and curing behavior, strength and elongation, hardness and resilience when using rice husk carbon black (RHCB) compared to regular N330 carbon black. The results indicated that non-modified RHCB does not contribute to strength improvement but it is non-detrimental on elasticity and resilience of the compound.
- 16:30 Bottom-Up Cost Modeling of Lithium-Ion Battery Cells for Electric Vehicle Applications
Lithium-ion Batteries (LIBs) have come a long way with various improvements to make them more efficient, compact, and safe while simultaneously enhancing the energy density and cycle life. If it is possible to improve the technicalities to lower the cell cost by indicating some potential solutions, the economic issues in LIBs automotive applications can be addressed. This study intends to approach a bottleneck solution for pure Electric vehicle (EV) cost reduction. The BatPaC 5.0 modeling tool is used to examine different cell chemistries (NMC811-Graphite(Gr), NCA-Gr, LFP-Gr, LMO-Gr, and 50%/50%NMC532/LMO-Gr) and determine the accuracy of the hypothesis made on the effect of positive electrode coating thickness of LIBs, on the cell cost, gravimetric energy density and volumetric energy density in high volume production. Using the above assumption, it is obtained that doubling the coating thickness of the positive electrode from 60 to 120 μm, reduces the cost in all cell types. But the highest by ~20% in LFP-Gr. And it emerges that increasing the positive electrode coating thickness of LIBs, lowers the cell cost whilst improving the gravimetric energy density and volumetric energy density. Therefore, the positive electrode coating thickness can be considered a crucial parameter in cell cost reduction.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 650 6157 4206 Passcode: Mercon@T3
- 15:30 System Performance of Split Type A/C Units in High-Rise Residential Buildings with Different Condenser Arrangements
The split-type air conditioning (A/C) systems are widespread due to their high flexibility compared to the centralized A/C system in high-rise residential buildings, specially in the tropical region. As the condensers are placed in the restricted space in building re-entrants, poor cooling, malfunction, and energy wastage are common issues faced in these high-risers due to the heat column formation. The induced hot-air plume creates elevated temperatures in higher floors adversely impacting the energy efficiency of condensing units. The strength of the heat plume and the temperature rise depend on several factors including condenser arrangement, shape and size of the re-entrants, and air-conditioner loading conditions. Hence, the present study focused on analysing the heat column generation using CFD and evaluating group performance of the condensers with the different condenser arrangements using the performance indices such as GCPR, GCCR, and GCER. The results revealed that the group power performance of the split A/C units could be increased by 105% compared to the existing condition if the condensers are located within 1.5m from the exterior wall. Further, the indices provided direction to set a design guild-line to develop an energy evaluation procedure for the different types of arrangement of condensers.
- 15:45 Soft Pneumatic Grippers for Reducing Fruit Damage During Strawberry Harvesting
Strawberry is a delicate fruit that has substantial economic value. Strawberries can be easily damaged during harvesting due to their soft nature. Therefore, strawberry harvesting requires skilled labourers who can gently yet effectively handle this soft fruit. There is a skilled labour shortage for strawberry harvesting, so automating this process would benefit strawberry farmers. Here we present a novel soft gripper design to minimize strawberry damage during harvesting. The proposed gripper comprises two doughnut-shaped single chamber pneumatic actuators inspired by biological Sphincters. The proposed balloon-type actuator is fabricated from thermoplastic polyurethane (TPU) coated fabric by thermal sealing. The blocked force performance of this balloon-type actuator and the holding force of the doughnut-shaped gripper is experimentally evaluated. The balloon-type actuator can apply 19.3 N at 40 kPa when displaced by 20 mm. The developed soft gripper can apply a holding force of 14.8 N at 40 kPa. Preliminary field testing was conducted to validate the applicability of the proposed soft gripper for strawberry harvesting. The field test showed 100 % success in harvesting with 85 % success without any damage (n = 7). This shows the potential of the proposed soft gripper in reducing fruit damage during strawberry harvesting.
- 16:00 Variable Stiffness Soft Actuator Using Layer Jamming for Food Handling
This study proposes a novel hybrid actuator combining PneuNet with layer jamming actuation to address the problems with conventional soft pneumatic actuators such as stability and lack of integrated locking mechanisms. The introduction of sandpaper-based layer jamming element is made as a solution. A set of experiments were conducted to identify suitable sandpaper grit-level and possible layering arrangement for the jamming section. P220 grit sandpaper showed the best flexural strength change which was suitable for the jamming element. The hybrid actuator was tested to identify the deviation from the typical PneuNet actuator in the performance of bending angle and generated tip force. The novel actuator showed a 25% reduction in bending angle while producing a 300 maximum bending angle at 160kPa pressure. Tip force of the novel actuator didn't show a significant difference and it produced 2.3N force at 160kPa. The integrated jamming element can act as a locking mechanism for the novel actuator. Due to the relaxation of the PneuNet, actuating locking mechanism shows an average 30% bending angle reduction compared to the initial bending angle. A two-finger gripper was produced using the hybrid actuator and it was successfully tested on soft food handling with the integrated locking feature.
- 16:15 Design and Characterization of a 3D Printed Wave Spring for Use in a Flexible Robotic Arm
This paper proposes the use of wave springs as structural segments for soft, flexible robotic arms. Conventional robotic arms are limited in their use within confined spaces due to the lack of maneuverability and safety. Soft robotic flexible arms, inspired by biological counterparts such as octopus arms, snakes, and elephant trunks, are a solution for this limitation. They provide flexible limbs with redundant degrees of freedom that allow for bio-inspired extension, retraction, and bending motions. In this paper, we propose the use of a 3D-printed, soft wave spring as the skeletal structure for a flexible robotic arm. The design and fabrication of the wave spring are presented. The wave spring is characterized in terms of bending and blocked force performance. The wave spring is proposed to be actuated via tendons, and a kinematic model is developed to describe its motion. The motion of a wave spring segment was evaluated using a prototype setup. The results validate the applicability of a novel tendon-actuated wave spring actuator for use in flexible robotic arm applications. Experimental results show that a single wave spring actuator achieves a maximum compression ratio of 43% at 199.8 N, and a maximum bending angle of 29.3°at 17.25 N.
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 680 2195 3591 Passcode: Mercon@T4
- 15:30 Forecasting Model of Combining Mini Batch K Means and Kohonen Maps to Cluster and Evaluate Gait Kinematics Data
When people are getting old, some gait abnormalities may have happened in their walking patterns. It means, there may be slight differences in their physical performance. Due to the complexity of that evaluation, a machine learning algorithm can be used to cluster the gait patterns. Kohonen Maps (KM) and mini-batch k-means (MBKM) have been combined to cluster the gait parameters according to the age groups to identify the principal gait characteristics which are affected to the walking pattern. Dataset is consisting of 180 gait data based on the data which have been gained through the inertial measurement unit (IMU). When analyzing the results, the proposed algorithm is showing low computational cost and time which is more efficient. As well the results have been proved that the cadence is the most important and affected gait parameter when caused to a walking pattern of a person when he or she is getting older. These results provide clues for the health professionals to identify and evaluate the difficulties of walking patterns of patients according to age.
- 15:48 Chest X-Ray Caption Generation with CheXNet
Chest X-rays are provided with descriptive captions that summarize the crucial radiology findings in them in natural language. Although chest X-Ray image captioning is currently done manually by radiologists, automating it has received growing research interest in the medical domain because it is a tedious task and the high number of medical reports that are to be generated daily. In this paper, we propose an automatic chest X-ray captioning system consisting of two main components: an image feature extractor and a sentence generator. We did our experiment in two approaches. First, we tried using LXMERT, which is originally designed for question answering, as the sentence generator in our model combined with the Faster RCNN model. Second, we used CheXNet and a memory-driven transformer as the feature extractor and the sentence generator respectively. We trained and tested our model using the IU chest X-ray dataset. We evaluated the model using the BLUE, ROUGE-L and METEOR metrics which shows the CheXNet based approach outperforms the latter models.
- 16:06 A Deep Learning Ensemble Hate Speech Detection Approach for Sinhala Tweets
We live in an era where social media platforms play a key role in society. These platforms support most of the native languages and this has enabled people to express their opinions conveniently. Also, it is very common to observe that people express very hateful opinions on social media platforms as well. Several studies have been carried out in this area for the Sinhala language with traditional machine learning models and none of them have shown promising results. Further, current approaches are far behind the latest techniques carried out in high-resource languages. Hence this study presents a deep learning-based approach for hate speech detection which has shown outstanding results for other languages. Moreover, a deep learning ensemble was constructed from these models to evaluate performance improvements. These models were trained and tested on a newly created dataset using the Twitter API. Moreover, the model generalizability was further tested by applying it to a completely new dataset. As per the results, it can be observed that the proposing approach has outperformed the traditional machine learning models and is well generalized. Finally, the experimentation with extra features also reveals that there is a positive impact on the performance using extra features.
- 16:24 Performance Comparison of Sea Fish Species Classification Using Hybrid and Supervised Machine Learning Algorithms
In the domain of autonomous underwater vehicles, the classification of objects underwater is critical. The hazy effect of the medium causes this obstacle, and these effects are directed by the dissolved particles that lead to the reflecting and scattering of light during the formation process of the image. This paper mainly focuses on exploring the best possible image classifier for the underwater images of the different fish species. The classifications were carried out by different hybrid and supervised machine learning algorithms such as Support Vector Machine (SVM), Random Forest (RF), Neural Networks (NN), Logistic Regression (LR), Decision Tree (DT), and Naive Bayes (NB). This study compares the algorithms' accuracy and time and analyzes crucial features to decide the most optimal algorithm. Furthermore, the results of this paper depict that using dimension reduction methods such as PCA and LDA increases the accuracy of some algorithms. Random Forest was able to outperforms with a higher accuracy of 99.89% with the proposed feature extraction methods.
- 16:42 Kansei Color Concepts for E-Commerce Website Design - A Case Study Using Designerwear Websites
Kansei Engineering (KE) is an effective-engineering methodology that focuses on consumer emotions in conjunction with product features where they are translated into design elements. KE can be used to improve the user's emotions and feelings towards products. This concept can be applied any product including web-based products. Taken together, the study focused on how to use the color concept to improve user perception of web interfaces using KE in the context of e-commerce designerwear websites. Designerwear websites were selected as the product property space of the case study. Then the design elements that can be identified in the website UIs were identified which include colors, layout, typography, etc. Based on a thorough review of literature, the Importance of color concepts as a design element was identified among others and selected for further analysis. A questionnaire survey was conducted to collect the psychological measurements of the Kansei Factors. The measurements were collected using a semantic differential scale. To identify the factors and the prominent Kansei words, data analyses were done employing Principal Component Analysis. Based on the results of the PCA, the main results of the study exhibit a data set of color concepts related to the final selected Kansei Words.
Thursday, July 28
Thursday, July 28 8:00 - 8:30
Thursday, July 28 8:30 - 9:30
Access to Zoom Session: 1). Click on zoom icon above for link, OR 2). Use meeting ID and password below with App, Meeting ID: 613 9660 7203 Passcode: Mercon@G1
Thursday, July 28 10:00 - 11:30
- T1-2-1.1 10:00 Framework for Sustainable Management and Utilisation of Wetland Resources: A Case Study of the Madinnagoda Marsh
Wetlands, the lands of areas saturated with water throughout the year or seasonally, are the vital ecosystems of the earth. Madinnagoda marsh (wetland), in the suburbs of Colombo, is one such valued ecosystem embracing the sad truth of wetland degradation that has occurred persistently during the past few decades. Therefore, this study was carried out to develop a framework focusing on the sustainable management and utilisation of wetland resources at Madinnagoda marsh. The DPSIR (Drivers-Pressures-State changes-Impacts-Responses) framework was used for the study, an excellent tool for analysing environmental issues and devising sustainable solutions. This study attempts to further develop this Framework and then test it by applying it to Madinnagoda marsh as a case study. The usefulness of the Framework in appraising strategies to sustainably manage and utilise the wetland resources was measured as per the level to which its strategies fulfil the 17 Sustainable Development Goals (SDGs). Since there is no ongoing development plan for Madinnagoda marsh targeting its sustainable development, this research study leaves the validation phase as a future work - though a hypothetical situation is proposed to ensure that the validity of the Framework that has been proposed is well demonstrated.
- T1-2-1.2 10:15 Study on Adequacy of Traditional Water Yield Forecasting Methods Focusing on Two Dry Zone Basins in Sri Lanka
The majority of dry zone basins are still ungauged in Sri Lanka, and this has led to uncertainties in the planning and development of water management infrastructure. The Irrigation Guideline of Sri Lanka (IGM) has been recommended to estimate the basin yield, but there's no appropriate evidence to evaluate the accuracy of the estimation. To fulfil this gap and for reliable yield estimation, a proper comparison should be undertaken incorporating the available water yield models. The IGM and HEC-HMS models were selected and compared by using the observed streamflow data of Kirindi Oya and Maduru Oya in the present study. Model parameters were identified by an extensive literature survey. Daily and 75% probable rainfall data were considered as the input data for the models and the model results were compared with the observed streamflow data. Basically the evaluation has been carried out by using the flow hydrograph, annual water balance, flow duration curves, runoff coefficients and the MRAE value as an indicator. Here, it can be concluded that the IGM is still the best model for yield estimations in the dry zone watersheds and it was identified that rainfall act as the key factor for the variation of the yield.
- T1-2-1.3 10:30 Investigations on Wave Energy Characteristics in South-Western Coastline of Sri Lanka
The aim of the study is to investigate the wave power potential around the south-western coast of Sri Lanka and its spatio-temporal and directional distributions based on 5 years (1999 to 2003) of simulated wave data. The analysis results show that the annual mean wave power in the region is exceeding 10 kW/m while the available monthly mean wave power values are higher than 5 kW/m throughout the year. Eight study points were selected along the nearshore coastline for a detailed assessment. The calculated annual and monthly mean wave power values at the selected points showed that the south-west coast has a higher potential than the west coast except near Matara. The temporal and directional variations were also assessed in selected points using statistical indices and wave power roses, and those revealed that the region has moderately stable wave power with narrow directionality. Moreover, the possible annual electric power outputs from three wave energy converter devices (WECs) were estimated at all the study points using wave scatter diagrams and publicly available power matrices, and the results reveal that the nearshore area from Galle to Weligama is most suitable for wave energy harvesting.
- T1-2-1.4 10:45 Climate Elasticity of Runoff in Kalu and Kelani River Basins in the Wet Zone of Sri Lanka
This study estimates the climate elasticity of runoff concerning precipitation and evaporation, in the Kalu river basin and Kelani river basin in the wet zone of Sri Lanka. The Ellagawa subbasin of Kalu river and Hanwella subbasin of Kelani river were selected for the assessment. The non-parametric estimator was selected based on the simplicity to assess the climate elasticity of runoff in the selected wet zone basins under current climate scenarios. At the same time, the climate elasticity under synthetic climate change scenarios was assessed using a hydrological model. HEC-HMS rainfall-runoff model was selected based on the accessibility, flexibility, reliability, and data requirement to simulate streamflow. The rainfall elasticity and evaporation elasticity were estimated for prevailing climate conditions. According to the model results, climate change results in causing -41% to 31% change in runoff in the Kalu river basin and -49% to 23% change in runoff in the Kelani river basin under synthetic climate change scenarios that were developed for the period of 2016-2035 considering the predicted precipitation and evaporation changes comparative to the baseline period of 1986-2005.
- T1-2-1.5 11:00 Study on Climate Elasticity of Runoff in Kirindi Oya and Maduru Oya Basins in Sri Lanka
Water management decisions commonly depend on monthly to seasonal runoff forecasts due to climate change. A review summarizing the findings related to climate change impacts on runoff in the dry zone is carried out in this article. This study is based on the climate elasticity of runoff in Kirindi oya and Maduru oya basins. Water scarcity and unpredictable high amount rainfall events affect the runoff prediction. This paper used the HEC-HMS model to analyze the data and non-parameter estimation to find the elasticity of climate parameters to runoff for making a future prediction using available limited data resources. The hypothetical climatic changing scenario has given the relationship between runoff and climatic parameters by comparing each parameter. The resulting analysis will provide sights on the relative benefits of investments toward improving runoff monitoring versus improved climate forecasting.
- 10:00 Multicomponent Heavy Metals Adsorption by Raw Coir Dust and Processed Coir Pith: Experimental Investigation and Life Cycle Analysis
Coir is an abundant bio-resource coming out as coconut industry residues. With the high fiber content and porous surface area, coir can be utilized as an adsorbent for heavy metal removal from water. This study investigates the capability of multi-component heavy metal removal using raw coir dust and processed coir pith. The capabilities of raw coir dust and processed coir pith samples to remove the major heavy metals are measured by the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) method. Raw coir dust indicates higher capabilities of heavy metal removal, compared with processed coir pith, recording the highest efficiencies of 17.66%, 21.27%, 18.90%, 6.66%, 12.87%, 21.63%, and 24.29%, for As, Cd, Cr, Cu, Mn, Ni, and Pb, respectively. The study also evaluates life cycle energy consumption and global warming potential of the two adsorbents. Production of one tonne of processed coir pith accounts for a life cycle energy consumption of 705.53 MJ and global warming impact of 248.15 kg CO2eq while raw coir dust shows insignificant life cycle energy consumption and global warming potential. The effect of adsorption conditions on heavy metal removal efficiencies, stage-wise life cycle analysis, and the appropriateness of coir as environmentally-benign heavy metal adsorbents are discussed.
- 10:15 Multi-Objective Optimization Methodology for Cryogenic Air Separation
Cryogenic air separation processes are used to produce gases with different quantities and qualities and the process has a tight integration of heat and mass. Like in many other chemical processes, various conflicting objectives must be achieved in this process. Cryogenic air separation process can be used to maximize the oxygen purity and nitrogen purity, each separately or in combination. In this study cryogenic air separation process was simulated using Aspen Plus and the data generated from the simulation were analyzed for multi-objective optimization in MATLAB using genetic algorithm. Three scenarios based on uncertain product demand were examined: maximize O2 purity, maximize N2 purity and maximize both O2 and N2 purity together. The reflux ratio of high-pressure column (RR) was found to significantly alter the purity of final products. The effect of waste flow rate on purity of products was found to be significant depending on the selection of the position of waste stream stage. The position of waste stream was only found to be significant below the main feed stream of the low-pressure column. Multi-Objective Optimization is useful in identifying the optimum conditions of the process variables for product requirements with conflicting objectives.
- 10:30 Path to Predict the Vapor Pressure and Enthalpy of Vaporization of the Components in Essential Oils
Essential oils contain terpenes and volatile compounds which are widely used in flavor and fragrance, cosmetic, and medicine industries. Fractionation of essential oils separate these compounds and modelling, and simulation plays a key role in optimizing the fractionation processes. The success of modelling and simulation of fractionating the essential oils heavily depends on the accurate prediction of vapor pressure and enthalpy of vaporization. This study examined the applicability and reliability of predictive methods for estimating the vapor pressure and enthalpy of vaporization of essential oils. Ten compounds were selected as case study, based on the export market for essential oils in Sri Lanka. Antoine method was found to give accurate and reliable data for all the ten compounds. But the use of Antoine method is limited due to unavailability of Antoine coefficients for most of the essential oil compounds over a wider range of temperatures. The selection of the suitable corresponding states group contribution method was found to depend on the type of compound and the range of operating temperatures. Based on the results of this study, the path to select the most suitable predictive method for a given essential oil compound with the applicable range of temperatures is recommended.
- 10:45 A Novel Brick Made from Clay Brick Waste/Rice Husk Ash/Cement to Adsorb Heavy Metals and Organic Dyes in Wastewater
We propose a composite brick made of rice husk ash, brick waste and cement for convenient application of the adsorbent and removal (after the adsorption is completed). Four commonly found adsorbates in industrial wastewater effluents (i.e. Pb(II), As(V), Hg(II) and Malachite green dye (MG)) were selected and the adsorption studies were conducted at 25°C. Results indicate that the brick is capable of removing 98.86%, 78.63%, 22.22% and 99.97% of Pb(II), As(V), Hg(II) and MG, respectively. These values are close to individual removal percentages by rice husk ash and clay brick and clay brick waste. The equilibrium loading (q_e) follows the order Pb(II) > As(V) > MG ≈ Hg(II). Further, Pb(II), As(V) and MG follow the pseudo second order kinetics and the film diffusion becomes the rate-limiting step. The strength of the adsorption bond follows the order Pb(II) > As(V) > MG and the adsorption rate decreases according to MG > As(V) > Pb(II) order. Considering its adsorption efficiency and effectiveness, the proposed brick can be identified as an efficient, effective and convenient solution to treat industrial wastewater streams.
- 10:00 Development of a Steady State Voltage Regulation Method for Power Distribution Networks
Distributed generation (DG) can be known as the power generating technologies that are installed at or close to the power consumption locations and it consists of a significant number of advantages for the power system in which it would reduce the transmission loss to a greater extent. On the contrary, it will be the cause of fluctuating the voltage on the distribution line. Many countries are inclined to observe the over voltage and under voltage fluctuations due to the high integration of inductive loads and distributed generation such as solar and wind power systems. Consequently, the active distribution system is supposed to be properly managed and coordinated. This study is mainly focusing on minimizing the voltage variation of a standard IEEE 33 bus bar system with the efficient placing of custom power devices on it. Moreover, voltage variation when distribution generations and inductive loads are presented on the bus bar system is studied. According to the results, it has been seen that the voltage variation in the existing distribution network can be minimized by placing a static var compensator at optimal locations.
- 10:15 Application of Novel Evolutionary Algorithms for Analyzing the Impact of Integrating Renewables on the Adequacy of Composite Power Systems
The adequacy evaluation of modern renewable-rich power systems tends to be a computationally challenging task due to variations of renewable power generation. Recently, more computationally efficient evolutionary algorithms and swarm intelligence-based methods are utilized for evaluating the adequacy of power systems. In this paper, the authors have proposed a wind and solar integrated composite system adequacy evaluation framework using an Evolutionary Swarm Algorithm (ESA). The system failure states which have a higher probability of occurrence are explored using the ESA to estimate the adequacy indices of the system. The wind and solar power generation are modeled using a clustering-based method considering their annual effective power output. Moreover, the correlation between the system load and renewable power generation is modeled in the adequacy evaluation framework. Using the proposed framework, several case studies are conducted on the IEEE Reliability Test System to analyze the impact of integrating renewables on the adequacy of composite systems. The results show that wind generation tends to improve system reliability than solar due to its higher availability. In addition, the equivalent capacities of wind and solar generators are found to be 125MW and 215MW against a 50MW hydro generator.
- 10:30 Converting a Commercial-Consumer-Fed, Ring Distribution System into a Diesel-Solar Hybrid Microgrid: Technical Feasibility
Complex distribution networks like ring or meshed networks are applied for commercial and industrial cities demanding reliable power supply. Diesel generators are connected to the network to maintain system reliability under emergency states. With increasing penetration of non-dispatchable, rooftop solar-PV, proper planning is required to maintain system stability and reliability, under aforesaid complex network arrangements. Commercial and industrial cities don't follow the conventional diurnal load patterns, but presents load patterns similar to the diurnal generation curve of solar-PV. Thus, by introducing solar-PV, required diesel generation capacity can be reduced. Also, the system reliability and stability can be improved if the system is operated as a microgrid. This paper evaluates the ability of forming ring-radial connected hybrid-microgrid based on an existing network for a commercial city with peak day-time loading. The aim is to increase the penetration of solar-PV and system stability and reliability. Small-signal stability analysis reveals that, even with 100% solar-PV, the islanded microgrid in normal state is stable under different diesel generation integration topologies tested. The system becomes unstable due to small perturbations under the N-1 emergency operation in some topologies, this study allowed identification of the proper diesel generation integration topology for the proposed microgrid.
- 10:45 Analyzing the Optimum Contact Angles of Water Droplets to Mitigate the e-Field Stress on Polymer Insulators
The water droplets present in the insulator surfaces cause variation in the e-field along the insulator surface. Variation in the e-field can lead to flashover and accelerate the aging of the insulator and ultimately will end up in the breakdown of the insulator. The contact angle of water droplets is also a factor that determines the e-field variation. In this study, the effect of the contact angle of water droplets is analyzed using a simulation approach for different cases considering both pure and contaminated outdoor polymer insulators. The results show that the optimum range of contact angles of water droplets can be concluded as 70 to 120 degrees for a pure insulator while the optimum range for a polluted insulator can be given as 70 to 100 degrees
- 11:00 Development of Multi-Winding-Transformer Assisted Diode Converters for Improved Utility Interface
This paper presents a development of multi-winding-transformer assisted converters for improved utility interface. The proposed system is 96 pulse AC-DC converter which consists of two parallel connected 24-pulse AC-DC converters together with eight phase shifted diode bridges. Other than that, an Interphase transformer and a Zero sequence blocking transformer arrangements are used. The proposed converter is simulated, and results are presented and analyzed in this paper. It has improved power quality aspects. Furthermore, from acquired results, viability of the proposed system is ensured for its applications.
- 11:15 Supervised Non-Intrusive Load Monitoring Algorithm for Identifying Different Operating States of Type-II Residential Appliances
Due to the increase in electricity demand and the rapid depletion of fossil fuels, energy management has become a critical issue over the last two decades. Thus, researchers, utility suppliers, governments, and policymakers are working in tandem to develop novel solutions. In recent years, solutions based on Intrusive Load Monitoring (ILM) and Non-intrusive Load Monitoring (NILM) have garnered the interest of many researchers. However, NILM systems are less difficult to implement and more cost-effective than ILM systems. Even though available NILM- based solutions can identify single-state devices with acceptable accuracy, identifying the various operating states of multi-state devices remains a problem. This research work proposes a novel supervised learning algorithm to correctly identify the operating states of multi-state residential devices. Results obtained through extensive simulations indicate that the proposed algorithm can achieve device and state identification accuracy of 93 percent and 91 percent, respectively.
Thursday, July 28 10:00 - 12:00
- 10:00 Factors Influencing Online Fast-Food Ordering Intension Among Millennials and Generation Z - Evidence from Sri Lanka
The advancement of information and communication technology, and increased Internet penetration, have altered the nature of consumers' everyday activities with a majority of offline activities switching to online activities. This is a common occurrence in the online fast-food ordering domain too. Although online fast-food ordering has been researched by many academics, fewer studies have been conducted in the Sri Lankan context. Thus, this study aims to bridge this knowledge gap and make recommendations for increasing the quality of online fast-food ordering. In this study convenience, website quality, quality of food, and social influence have all been identified as factors that impact online fast-food ordering, whilst consumer satisfaction serves as a mediating variable. Findings from 384 respondents aged 20 to 40 years old residing in the western province, Sri Lanka revealed that website quality is the most influential element while convenience has no influence on online fast-food ordering intentions. Customer satisfaction was also discovered to moderate the relationship between website quality, quality of food, and online fast-food ordering intention, as well as social influence and online fast-food ordering intention. Finally, premised on the discussions, recommendations have been made in the areas of promotion, food delivery, food quality, website design, and advertising.
- 10:15 A Profit Maximization Approach for Organic Short Food Supply Chains
Demand for organic food is rapidly increasing. This is despite several constraints in the process of producing organic foods. Producers should aim to maximize their profit by catering to the rising demand of this niche market. Manufacturing cost per unit is comparatively higher in the organic chain compared to the conventional chain. Hence, producers must make critical decisions when supplying their products to different markets. A Python-based Linear Programming Optimization model tested using Google Optimization Tools has been developed to identify the optimum delivery volume that should be supplied to each market which has been identified in this empirical study. The designed model aims to maximize profits by minimizing unsold products and postharvest waste. The developed model can guide producers who operate in the organic perishable supply chain to gain market benefits in short food supply chains. There is a lack of research on sustainability aspects in agricultural coordination and applications in supply network performance. Therefore, this study fills this gap by addressing the issue of postharvest waste in the distribution process of organic vegetables and fruits. The model can be extended into other product variants to validate the model's applicability under different market scenarios.
- 10:30 Smart Traffic Light Control System Based on Traffic Density and Emergency Vehicle Detection
Transportation is one of the main aspects of a country's economy. Most economic sectors are laid upon detrimental results due to an unorganized transportation network. This is a crucial issue faced by developing countries. There is no doubt that highways should be built in order to maximize the throughput of the transportation network; nevertheless, expansion of existing roads is also not applicable in countries like Sri Lanka due to its ceasing land area with increasing population. Thus it is essential to switch to a more efficient, technologically advanced approach to solve this issue. In addition to the typical congestion scenarios, the prevailing pandemic situation has realized the importance of prioritizing ambulances when it is caught amidst a traffic jam. Pedestrians are another vital part of the road network. Effective and safe pedestrian crossing will ensure the reduction of road accidents while improving the existing heavy traffic. A smart traffic monitoring system integrated to control the traffic signals is the ideal solution in this context. This paper proposes a smart adaptive traffic monitoring and control system to detect vehicles and pedestrians and prioritize emergency vehicles. A new Convolutional Neural Network is trained with YOLOV3 architecture to achieve 91.3% detection precision.
- 10:45 Challenging Factors to Adopt Circular Economy in Sustainable Food Supply Chain
Even though circular economy has captured global attention recently with its sustainable implications, the adoption takes a much slower approach, particularly in the food supply chain. This study attempts to identify challenging factors that hinder the adoption of circular economy in the food supply chain. A total of 17 challenging factors are identified via a systematic literature review. The challenging factors were grouped into 6 categories: economic, social, institutional, technological and informational, supply chain, and organizational. Literature frequency analysis method combined with an article-level research citation metric of field-weighted citation impact was employed to prioritize the challenging factors based on the literature importance. Thus, the findings reveal that cost efficiency considerations, less enforcement of legislation and regulations, and no long-term shared vision among stakeholders are the three most critical challenging factors to adopt circular economy in the food supply chain. The findings will help managers, decision-makers, practitioners, and governments to formulate policies and strategies to implement circular practices in the food supply chain effectively.
- 11:00 Leadership in Change Management Decisions for Successful ERP Implementation - A System Dynamics Perspective
Nowadays, more and more organizations are moving towards Enterprise Resource Planning (ERP) system solutions from their old legacy system solution. ERP is a project that requires a significant amount of change management to ensure a successful implementation. It involves not only large-scale technology changes, but also major shifts in process and organizational behavior. Despite this, literature haven't extensively explored the interrelation between the challenge in change management and ERP implementation. This study intends to discuss and evaluate how the leadership will assist to the development of change management decisions in ERP implementation. Empirical evidence suggests that leadership responsibilities such as effective communication between management and employees, building core team productivity, increasing the quality of reengineering process and top management commitment will drive the implementation to the success. Relative Importance Index (RII) used to define the research problem. Then system dynamics methodology was used to analyse and validate the dynamic behaviour of ERP implementation. Findings of the research paper emphasis the importance of various leadership factors in change management decisions how those will influence the success of ERP implementation in the long run.
- 11:15 Identifying Quality Related Risk Factors in Spices and Allied Products for Export Market
Sri Lankan spices sector is one of the leading export sectors among the export products and a significant part of the country's economy. But Sri Lankan spices exporters face issues with quality, packaging, standard certifications, and value addition. The study focuses on trade competitiveness and trade barriers of regional trade agreements, in the export trade of spices. The purpose of this study is to identify the quality related risk factors for the exporters in spices industry and suggest the risk mitigation strategies. Potential issues were identified by conducting a background study and obtaining industry experts' opinions. Thereafter, selected factors were analyzed through Interpretive Structural Modeling (ISM) technique that presented the relationships between ten quality standard related risk factors. The study was able to identify Inadequate laboratory services (R2), Sudden changes in quality parameters (R5), and Lack of awareness of value chain partners (R4) as the top three risk factors among the identified risks. The MICMAC analysis shows that are highly independent risk factors in the system. Also, they are the risk generators in the system according to the hierarchy. The key areas of the risk mitigation strategies are technological enhancements, research and development, and initiatives to make awareness on industry.
- 11:30 Impact of Lean Manufacturing on Inventory Turnover Performances: Evidence from the Sri Lankan Apparel Industry
Evaluating and systematically identifying the impact of lean manufacturing has become crucial to organizations, especially for the apparel industry, where lean navigation can be seen primarily. This study aims to critically evaluate the impact of lean manufacturing practices on inventory turnover performance. This research analyzes inter-related lean practices using an addictive index model that shows the multi-dimensional face of lean manufacturing. This research is based on just-in-time lean bundle, total quality management lean bundle, and total productive maintenance lean bundle. Further, relationships between these bundles and inventory turnover performance have been critically evaluated through a cross-sectional design where data was collected from 72 respondents by distributing an online questionnaire to the selected sample using a judgmental sampling method. The collected data was analyzed by using the Statistical Package for Social Science software. The results indicate that all three lean practice bundles have a strong and significant relationship with inventory turnover performances. The conceptual model developed to study this research was identified with a high model fitness. This research recommends implementing all lean manufacturing practices together to improve the inventory turnover performance because the total model regression was higher than the values of the independent correlations between independent and dependent variables.
- 11:45 A Capacitated Vehicle Routing Problem Model for Stationery Industry
This paper aims to present an optimization solution for the distribution of stationery products with a seasonal demand pattern. The problem structure is that the capacitated vehicle routing problem is one-to-many with multiple products, where each customer has a variety of product types and demands. It is observed that distance has varied by 56% between the season and off-season periods. A mixed-integer linear programming model was used to give an optimal solution and the Gurobi optimiser was used to arrive at the solution. The objective of the research is to determine the appropriate number of vehicles used to complete the delivery process in both seasonal and off seasonal periods, together with the route sequence of every vehicle, such that the distance-related costs are minimized with effective vehicle capacity utilization.
Thursday, July 28 11:45 - 13:15
- 11:45 Perceived Walkability Evaluation in Rail Transit Station Catchment Areas in Bangkok
Urban rail transit is being developed in the developing countries to alleviate traffic congestion. However, station access was generally not good, especially in the area within a walking distance around the station. This study considered the walkability both objectively and subjectively. 25 rail transit stations in Bangkok were taken as a case study. The objective evaluation revealed that the station catchment areas were not pedestrian-friendly. This study proposes a concept of perceived walkability. Based on the structural equation modeling, the perceived walkability index was evaluated. The results revealed that the pedestrian perceived not only the objective or physical conditions, such as width and tree, but also the subjective attributes, such as safety and convenience. The findings shed light of improving the station area to enhance the transit-oriented development policies.
- 12:00 Crash Analysis on the Outer Circular Expressway
The road crash analysis helps to identify blackspots in the roadways specially in expressways where the vehicle speed is considerable higher. The crashes in expressways occur due to various reasons. However, it is imperative to identify such crash causes which leads up to accident blackspots. Therefore, this study was conducted with the aim of identifying the blackspots of the road section of the Outer Circular Highway of Sri Lanka where the study area spanned for a length of 19 km. The research study analyzed the governing traffic and the road geometrical parameters which have a potential influence towards the crashes in the blackspots. The study considered road related parameters such as the lane of crash occurred, presence of horizontal curve, vertical slope, K value, crossfall, presence of horizontal and vertical curve, outer safety fence type and inner safety fence type. therefore, in the research study, the most governing sub parameters in the blackspots were identified. The analysis was conducted to identify the most influential factors of each parameter with considering separately for the Left- Hand Side (L.H.S.) and the Right-Hand Side (R.H.S.) of the expressway.
- 12:15 Effectiveness of Manual Control of Traffic Signals During Peak Hours
One of the major reasons for congestion is ineffective control at intersections. During the peak hours there has been observed that many signalized intersections in city centers are controlled manually by police officers either by switching off the signal lights or by flashing amber. The objective of the study is to find the effectiveness of manual control compared to traffic signals. Four Junctions which are controlled manually during the peak hours were selected and modelled for three cases, existing posted signal time, updated traffic signal time, and traffic police phase arrangement and cycle time in VISSIM. Webster & Cobbe (1966) model used to design signals and modified to achieve optimum delay. Manual control results lesser delays than the existing signal time case. But updated signal times result even lesser delay than the manual control. When the junction is over-saturated, delays for manual control by traffic police result lesser delay than the existing signal times. Delays for minor road movement delays for signal control have significant reduction of delay than manual control. Daily variation of traffic also affects the junction delays significantly as the fixed cycle time signals are used. Introducing vehicle actuated signals will be an effective solution
- 12:30 Using AHP to Develop Sustainable Walking Environment: Case in Hochiminh City, Vietnam
Hochiminh City is developing a metro system, but the walking system around the stations has not been studied enough. Walking activity is still quite strange to most citizens due to the unfavorable walking environment despite its incredible benefits on people's health. In this study, we apply the Analytic Hierarchy Process (AHP) method to sort those elements in priority order. The experts in urban planning were divided into three groups with different job characteristics to provide a complete and factual standpoint. ANOVA and T-Test tested the results and showed that most experts have a relatively unifying opinion in the groups. There is only one element that lacks consensus among the groups of experts. From this study, twenty physical elements were selected and divided into five groups before being reduced to twelve applicable criteria for the limited budget of a developing country. Based on that, we can understand more about the views of each group of experts. These elements will help create a comfortable, safe, and convenient walking environment that encourages people to walk more for better health and purer city air quality.
- 12:45 Methodology of Developing a Tour Mode Choice Model of Workers in Western Province, Sri Lanka
This study is based on work tours which can identify by considering all the trips as a chain starting and ending at home. Tour mode estimation is one step in the Activity-Based Model needed to be followed once tour patterns are identified. The socio-economics/demographic characteristics of individuals and households, level of service attributes, tour/trip details, and land-use attributes influence tour mode. A choice model needs to estimate the tour mode using these influential factors. Assigning a tour mode for each tour is required before model formulation. The main objective of this paper is to propose a method to estimate tour modes for individuals in Western Province, Sri Lanka. The required travel details were collected from the CoMTrans 2013/14 Household Visit Survey data. This paper includes only the work tours and describes the methodology to estimate the tour mode choice model. The authors introduce a process to identify the tour modes out of trip modes. The descriptive analysis of tour mode with the tour pattern details is included. The estimated results in tour mode for Colombo district were presented. The mathematical techniques, details of data needed, and required software for estimating the tour mode choice model are mentioned in this paper.
- 11:45 Remote Sensing and GIS Approach to Monitor the Land-Use and Land-Cover Change in Kaduwela Metropolitan Area
This article depicts the impact of Land Use and Land Cover (LULC) change using multi-temporal remotely sensed data in the Kaduwela metropolitan area located in Colombo District for the period between 1997 and 2019. To obtain information from the satellite data, the Maximum likelihood supervised classification technique and post-classification change detection strategy were applied. Besides, Spectral indices were utilized to define the ground truth. Thus, the study area was divided into four main land use/cover classes, and hence five satellite images for the years; 1997, 2007, 2014, 2017, and 2019 with low cloud cover were identified. According to the study, urban development resulted in a significant conversion of vegetation cover to the urban development of around 36 km2 during the past 22 years. The generated map showed that between 1997 and 2019, the built-up area increased by 43.62 percent whereas vegetation cover decreased by 41.72 percent. The overall precision of the data produced ranged from 72 to 81 percent. The dramatic growth of the urban population will boost the risk of natural environmental diminishing. This study assesses the change in the LULC pattern for the previous 22 years, providing useful information for the urban planners to make sustainable environmental decisions.
- 12:00 Rare Earth Element Enrichment in Intrusive Rocks of Sri Lanka as a Potential Low-Grade Source
Owing to the crucial role-playing in the decarbonization of the global economy, the demand for rare earth elements (REEs) is burgeoning while the supply is highly uncertain. This lack of secure supply coupled with high-grade resource depletion has led to increased explorations on potential low-grade resources of REEs. Thus, the present study focuses on the enrichment of REEs in intrusive rocks in Sri Lanka - a prospective low-grade REE resource. We analyzed fifty-five rock samples from a few granitic bodies (Massenna, Thonigala, Arangala), Eppawala Phosphate Deposit (EPD), and Ratthota pegmatite for their REE concentrations. Amongst the studied prospects, EPD (4185 mg/kg), Arangala granite (2183 mg/kg), and Massenna granite (937 mg/kg) had high REE concentrations with increased LREE enrichments over HREEs. However, EPD contains processable REE minerals (apatite and monazite), and REEs can be extracted as a by-product after developing the phosphate fertilizer production flow. Thus, EPD is the highest prospective of all the studied intrusive rocks of Sri Lanka. Compared to global occurrences, although it is low-grade (0.48 wt% REO, 0.29 million tons REE reserve), such low-grade REE resources could become viable in the future due to the ever-increasing demand and the expected resource depletion of REEs.
- 12:15 Smartphone vs. Consumer-Grade GNSS for Field Studies: A Statistical Comparison
Smartphones have replaced not only the telephone but also most other devices such as camera, computer, torch, Global Navigation Satellite System (GNSS) devices etc. used in our day-to-day activities due to their multifunctionality. However, the accuracy of the inbuilt GNSS receivers on smartphones can be ambiguous and has concerns when used in field investigations due to internal and external factors. Despite the fact that these factors are well known, the degree of influence of these factors in the accuracy of components of location data provided by smartphones is unexplored. This study aims to statistically assess the influence of three factors (time of the day, landscape characteristics, and ability to track signals of multiple GNSS constellations) on the accuracy of spatial data provided by smartphone GNSS. The horizontal and vertical accuracy of smartphones are within 40m and 15m, respectively. The results reveal that the ability to track multi-constellation and landscape properties, respectively, has a significant influence on the horizontal and vertical accuracy of smartphone location information. Further, this study also provides insights to improve the reliability of spatial data collection using smartphones in outdoor environments.
- 12:30 Spatiotemporal Growth Dynamics of Invasive Plant Distribution in Bolgoda Lake, Sri Lanka: A GIS Based Approach
Inland water bodies in urban areas, such as Bolgoda lake, host vegetation covers that exhibit significant spatio-temporal variations throughout the year. Seasonal weather patterns, anthropogenic activities, such as surface mining, wastewater discharge and invasive plant growth typically govern these dynamics. Measuring, and monitoring, these factors over the spatial extent of these waterbodies require significant efforts. Yet, remote sensing and earth observation data can effectively minimize these efforts. This study employs both Landsat and Sentinel satellite data to estimate the normalized difference vegetation index (NDVI) and the normalized difference water index (NDWI) to develop a relatively accurate classification of the water-vegetation dynamics over the time of interest. The Google Earth Engine and ArcGIS software were used to download and generate the classifications over six years (2016-2021) for four different seasons (i.e., 24 processed images). The classified time series data show that the vegetation cover varies at two temporal frequencies. The annual variation of the water, vegetation, and non-vegetation (other) classes is consistent and cyclic. However, at a finer temporal resolution (i.e., on seasonal cycles), vegetation dynamics fluctuate rapidly. The study offers a scope for using the results to support policymakers in optimizing environmental resource management strategies for urban surface water bodies.
- 11:45 Active and Passive Based Hybrid Cell Balancing Approach to Series Connected Lithium-Ion Battery Pack
Lithium-ion battery (LiB) technology is extensively used in energy storage systems (ESS), electric vehicles, and portable devices. Optimal cell balancing techniques for a battery management system are essential for the operation of the Li Battery. This paper proposes a new passive and active-based hybrid cell balancing technique integrating switched resistor balancing technique and switched capacitor balancing technique to achieve less balancing time and less power dissipation with simple control and hardware. The proposed system has been mathematically modeled and simulated, and the results show a 30 % increase in the balancing time compared to the conventional capacitive balancing technique. Also, the control algorithm can adaptively operate to achieve better performance of the circuit. The simulation is done in the MATLAB Simulink environment.
- 12:00 Design of Complex Grounding System in Non-Uniform Soil Structure: Development of Grounding Design Software
Current practice for grounding system design is mainly guided by IEEE 80-2000 standard. This practice is an iterative process of changing design variables until safety requirements for step and touch voltages and maximum ground grid resistance are met. It uses rectangular or square shape mesh arrangements. However, most of earthing systems in buildings, telecom towers are very complicated and not pure square or rectangular. Furthermore, IEEE process only allows to design grounding systems under uniform soil approximations. Since there are significant variations in the soil resistivity present at actual sites, multilayer soil model approach has been found to be much more accurate than the uniform soil model. This paper presents a mathematical model to analyze both simple and complicated grounding systems under uniform or non-uniform (multi-layered) soil structures. A grounding design software package was developed using MATLAB App Designer, and its core algorithm and the key features are introduced. In order to check the validity of the results, they have been compared with the results taken from ETAP - Power system analysis software.
- 12:15 Low Voltage Cable Path Optimization Using Hightower's Algorithm and Simulated Annealing Algorithm
Improvement of energy efficiency has become a major aspect in many industrial and commercial sectors to gain a competitive advantage by reducing the operational cost of the installation. But the current mandatory requirements only consider the aspects of safety, initial investment cost and other physical constraints which results in lack of encouragement in concentrating on the lifetime energy loss happening due to the heat generated in minimum cable sizes selected and the additional cost incurred due to the suboptimal placement of the distribution switchgears. This paper proposes an overall cost reduction method in both the initial capital cost and the operational cost by using a process built with the help of the Hightower's algorithm and the simulated annealing algorithm. Here the cost reduction aspects in cable layout, cable size and distribution switchgear are considered, and a software tool based on the Python programming platform is introduced to increase the energy efficiency of the overall electrical installation. The results of the study show the positive outcomes in overall cost reduction when compared to the conventional approach used for the designing of low voltage installation distribution systems.
Thursday, July 28 12:15 - 13:00
- T4-2-2A.1 12:15 Selecting Optimum Seed Words for Wordle Using Character Statistics
Wordle, a word guessing game rose to global popularity in the January of 2022. The goal of the game is to guess a five-letter English word within six tries. Each try provides the player with hints by means of colour changing tiles which inform whether or not a given character is part of the solution as well as, in cases where it is part of the solution, whether or not it is in the correct placement. Numerous attempts have been made to find the best starting word and best strategy to solve the daily Wordle. This study uses character statistics of five-letter words to determine the best three starting words. We show that our proposed starting words perform better than the currently available suggested word configurations across three distinct data sets: of which, two are drawn from the official Wordle word database.
- T4-2-2A.2 12:30 Towards an Adaptive Communication Framework for Smart Devices
With the technological advancements we experience now-a-days, people have become more concerned about their social connections even when communication infrastructure such as cellular and Wi-Fi networks are not available. Previous attempts towards solving this issue have focused on specific use-cases such as disaster recovery applications or chat applications. We have identified the need for a framework which enables infrastructure-less communication and which can be reused in different use-cases. Therefore, we have designed and implemented the Meshify framework which enables smooth interaction among devices when there is no communication infrastructure available. Meshify takes into consideration efficient neighbor discovery as well as multi-hop routing and provides features such as private messages and broadcast messages. Finally, a prototype application MeshifyChat is developed based on Meshify framework, which enables real-time chats among people in proximity to support their social interactions independent of the existing communication infrastructure.
- T4-2-2A.3 12:45 Ontology Based Question Answering System for Sri Lankan Online School Education
Today, distance education is one of the world's most popular forms of education, and there are several opportunities for students to receive education online. Here, ontology can be considered one of the leading knowledge representation ways in e-learning systems. This research addressed students' learning difficulties in Sri Lankan online education during the past two years. Students had to learn from home via online video conferences or audio series taught by teachers. However, students could not learn by asking questions or referring to the library materials to improve their self-studying knowledge. To overcome this issue, this research developed an ontology for school children in Sri Lanka, focusing on their IT syllabus and improving their self-education knowledge. This aims to provide personalized content while improving information searching. Students can ask questions from UI, and questions are taken as an input parameter and generate a query while cleansing for matching processes. Answers are generated by connecting to the index database and ontology repository, and the end output is displayed in the user interface. In the evaluation, it was targeted to categorize the questions according to relevant components, and the research shows the questions that are categorized into relevant categories while enhancing the performance.
Thursday, July 28 13:30 - 15:15
- T3-2-3.1 13:30 Benchmarking Energy and Water Consumption of Supermarkets in Sri Lanka
Buildings are responsible for about 40% of global energy consumption, 42% of global CO2 emissions and about 30% of global fresh water consumption. Therefore, the importance of energy and water consumption benchmarking in buildings has become a major objective for governments and relevant authorities to reduce the energy and water consumption by the buildings. Energy consumption benchmarks for Commercial Sector, Hospitality Industry, Apparel Industry and Tea Processing Industry have been already developed and are available for Sri Lanka. However, Electricity and Water consumption benchmarking for Retail Supermarkets have not been established yet. Therefore, during this study, Electricity and Water consumption benchmarking for Sri Lankan Retail Supermarkets were estimated and proposed. According to the analysis, electricity consumption benchmarks were obtained as 780.0 kWh/year/m2 per sales floor area and 465.4 kWh/year/m2 per total floor area. Moreover, mean specific electricity costs were obtained as 19,465.90 Rs/year/m2 per sales floor area and 11,621.20 Rs/year/m2 per total floor area, provided that electricity cost is calculated per GP 2 tariff structure of Ceylon Electricity Board. In addition, Water consumption benchmarks were obtained as 246.5 L/year/m2 per sales floor area and 137.2 L/year/m2 per total floor area.
- T3-2-3.2 13:45 Estimation of Embedded Energy of Some Selected Vegetables in the Vegetable Value Chain, Sri Lanka
Vegetable value chain is an energy intensive process. Embedded energy of the vegetables from farm to the retailer market has a significant impact on the market prices of the vegetables. However, the market price of the vegetable does not directly depend on the embedded energy cost of a particular vegetable as the availability of vegetables in the market varies depending on the different harvesting seasons in the calendar year. Sri Lanka is an agricultural country which is self-sustain for its total vegetable requirement. This study explains the estimation of embedded energy of some selected vegetables in the vegetable value chain of Sri Lanka.
- T3-2-3.3 14:00 Sick Building Syndrome in Residential Apartments
Sick Building Syndrome (SBS) is currently a widely discussed topic all around the world since most of the population spends a majority of their time indoors. However, in Sri Lanka, there is less discussion on SBS. Among the contributory factors for SBS, polluted air plays a leading role while aggravating the situation with poor ventilation. To assess the magnitude of SBS prevail in Apartment buildings in Sri Lanka, a field study was carried out placing the focus on Total Volatile Organic Compounds (TVOC) and Carbon Dioxide (CO2) concentrations. A series of measurements were taken on selected Indoor Air Quality (IAQ) parameters in a sample of apartment buildings located close to the main highway. The IAQ monitoring was coupled with a questionnaire survey on SBS symptoms, building operational practices, and other related parameters. The results of the study revealed that IAQ parameters could correlate with SBS symptoms at different significant levels. Moreover, poor ventilation had been identified as a prominent contributory factor to substandard air quality which in turn would result in several SBS symptoms. The results of this research will be benefited Engineers, Architects, Developers, and the general public.
- T3-2-3.4 14:15 Numerical Analysis and Performance Optimization of a Flap-Type Oscillating Wave Surge Converter in Irregular Waves
Renewable energy plays a vital role in ensuring the sustainability of the world. Among different renewable energy sources, wave energy is one of the least-developed technologies. Out of the available Wave Energy Convertors (WEC) the Oscillating Wave Surge Converter (OWSC) is one of the most researched types of WECs due to its higher performance characteristics compared to many other WECs. In this background, this research focused on DualSPHysics-based numerical prediction of the energy conversion efficiency (ECE) and survivability of an OWSC in irregular waves observed in a selected coastal location of Sri Lanka. It was found that the Power take-off (PTO) damping coefficient, the density of the oscillating flap and the shape of the flap highly influence the ECE and the hydrodynamic forces on the WEC deciding its survivability. If the density of the flap is in the range of 400 - 600 kg/m3 and its shape is more concave, the ECE increases significantly (about 25%) while improving its survivability. On the other hand, a significant reduction (25 to 47 %) in hydrodynamic forces could be achieved using cone or semi-cone-shaped flaps at the expense of ECE which would be a good alternative for high energetic seas.
- T3-2-3.5 14:30 Effect of Envelope Energy Performance Enhancement Strategies on Building Energy Loads: Case Study for a Tropical Institutional Building
Building energy simulation tools are used during the design process of a building to improve its energy performance. In this study, envelope thermal performance enhancement strategies were evaluated using eQUEST building energy simulation software considering the energy saving achieved related to cooling and ventilation energy consumption, for a tropical institutional building, in order to compare their performance. Fixed and building shading strategies have resulted for about 3.9% energy saving and other envelope thermal performance enhancement strategies have resulted up to 4.7% energy saving. Further energy consumption variation with envelope and roof thermal transfer values (ETTV, RTTV) were also evaluated. The results have shown that ETTV has statistically significant correlation with averaged building cooling and ventilation energy consumption. The findings allow building designers to identify the best upgrade options for achieving code compliance in Sri Lankan institutional buildings.
Thursday, July 28 13:30 - 14:15
- 13:30 Elastic ORB: Non-Rigid Transformation Based SLAM
We present Elastic ORB, an improved implementation of a novel visual SLAM approach. Our system uses point cloud data to build the map of the environment and for the localization of the robot, odometry data is used. A frame-to-frame loop closure method is used at the back of the SLAM system using the concept of Deformation Theory. When building the reduced model of the map, the ORB keypoint extraction algorithm and the FPFH feature descriptor are used. Our system is capable of mapping a larger environment overcoming the limitations of existing SLAM systems which use the deformation theory at the backend.
- 13:45 Enhancing Human Robot Communication by Generating Spatial Information Using Uncertain Terms
Human interactions are not always specific and literal. In day-to-day scenarios, humans interact with each other in the manner that a lot of those involve uncertainties. When the robot has to interact with the user regarding an instance in a navigation scenario, the human user would effectively understand and react quickly if the robot interacts using the same uncertain concepts. However, the interactions, perception of situations, awareness of environmental parameters, and interpretations of those parameters should be accurate and human-like at the same time. Therefore, this paper proposes an intelligent system that has the capability to interpret spatial parameters and navigation parameters associated with navigation in a dynamic environment in a human-like manner. The proposed system considers the navigation of an intelligent wheelchair in a domestic environment. Parameters such as the velocity of the obstacles, distances to particular obstacles, and the size of the obstacles are perceived and interpreted according to the uncertainties attached to them. Understanding of the situation is enhanced by considering the fuzzy interpretations of numerical values of each parameter and the mutual effect of other parameters on these fuzzy interpretations of a particular parameter.
- 14:00 Experimental Evaluation of Steering Actuator Configuration on the Behaviour of a Soft Growing Robot
Soft growing robots are a novel concept that uses fluid flow to increase in length at the tip. Using effective steering mechanisms, soft-growing robots can grow along the desired path. Series pneumatic artificial muscles (sPAMs) are used as steering actuators in contemporary soft-growing robots. This paper presents the experimental evaluation of the effect of the sPAM configuration on the bending of a soft-growing robot. The paper also includes the design and fabrication of the robot body and the sPAMs, the experimental setup, and the analysis of the observed results. The soft-growing robot body and sPAMs are made of low-density polyethylene (LDPE). The effect of four sPAM configurations (n sPAMs in m groups) on the bending angle and the blocked force is experimentally evaluated. Experimental results show that the bending angle is proportional to the number of sPAMs in a group (Bending angle reduces from 33° to 12° as the number of sPAMs in the group is reduced from 6 to 2). The blocked force applied by the robot tip remains constant over all the tested sPAM configurations. Hence, by varying sPAM configurations, a designer will be able to change the bending angle of a soft-growing robot without affecting tip forces.
Thursday, July 28 14:00 - 14:30
- T1-2-3A.1 14:00 Application of LSTM and ANN Model for Traffic Time Headway Prediction in Expressway Tollgates
Traffic time headway is essential to support decision-making in safety management, capacity analysis, and service provision. Many studies on the time headway distribution on highways and urban roads serve two primary purposes. The studies that serve the latter purpose, service level, have not been given adequate attention. In fact, at manual toll stations, traffic congestion is still a severe problem. Predicting the time headway at toll stations becomes extremely meaningful when the service providers can allocate resources reasonably, minimizing waiting time in off-peak periods and utilizing resources during high-demand periods. This study applies two modern machine learning methods to predict the time headway at Niigata toll stations, Japan, namely Long Short-term Memory (LSTM), which only requires simple input of time series, and Artificial Neural Network (ANN), which requires some additional external features. The data set is the time headway of vehicles on expressways, along with the weather information and the vehicle's average speed for five working days. There needs to be a trade-off between computation time, input data complexity, and model accuracy. Thus, tollgate operators could choose a suitable model based on their actual situation.
- T1-2-3A.2 14:15 Cyclists and Motorcyclists Detection in Traffic Video Footage
The Cyclists and Motorcyclists detection in streaming traffic video has been a challenging task due to irregular movement within the road and smaller image size within the frame. This paper is proposed a novel method of image segmentation of cyclists and motor cyclists and subsequent detection with image moments in traffic video footage. However, isolation of pedal cycles and motorcycles with perfect object boundaries has been a challenging problem with respect to other vehicle categories in the context of image segmentation. Irregular shape image segmentation for pedal cyclists and motor cyclists using a novel recursive image segmentation algorithm is proposed in this work. The recursive image segmentation algorithm is applied to extract image pixels of a moving object in the binary image. The extraction of all the pixels of a bicycle could be accomplished successfully using the proposed algorithm. Subsequently, pixel count, height, width and the image Hu moments are recorded and used to identify the motorcycle category. An accuracy of 91.2% was obtained for video footage duration of 6 minutes video sequence for the detection of cyclists and motor cyclists. This recursive image segmentation method has successfully been applied in identification of motorcycles in traffic video sequences.
Thursday, July 28 14:00 - 15:30
- 14:00 Determinants of Integrated Citizen-Centric E-Services in the Public Sector of Sri Lanka
This study aims to develop a conceptual model that could be adopted for the development of the existing e-government framework in Sri Lanka with the use of a more citizen-centred approach. Policy and Governance, E-government Service Quality, Information Technology Infrastructure and Organizational Commitment were identified as the most influential factors to implement a successful citizen-centred e-government framework. The study was carried out considering both users and nonusers of existing e-government services. As the findings unveiled, the most influential factor for existing users is the e-government service quality, whereas that of nonusers is the organizational commitment to the adoption of citizen-centred e-government services in Sri Lanka.
- 14:15 A Study on How Organizations Perceive Synergy Between Lean and Industry 4.0
Over the last few decades, the advent of lean spread over most manufacturing industries as a best practice for minimizing waste, increasing efficiency, and maximizing resource usage. However, in the recent past, Industry 4.0 is under debate to be taking over the existing best practices of the manufacturing industry as digitalized production systems. This has sparked concern as to how these changes would affect the well-established lean systems. Hence, through this research, we explore how lean would transition into the digital era in the apparel industry. The information and insights generated were used to map relationships between Lean and Industry 4.0 as well as to understand the strength of the given relationships using non-parametric statistical methods. The paper discusses key elements of compatibility as well as incompatibilities under different segments of both Industry 4.0 and Lean in the form of a comprehensive matrix. It also reflects the nature of synergy relationships compared against different levels of Industry 4.0 maturity.
- 14:30 Framework to Promote Automotive Remanufacturing: Case Study of Automotive Repairing, Rebuilding, and Remanufacturing Industry in Sri Lanka
The growth of remanufacturing has seen its application in automotive, electronic equipment, furniture, and medical devices in the global product portfolio. Remanufacturing is identified as a promising end-of-life/use product recovery strategy that has been used in the world for decades as a solitary value-adding process that upgrades a product from used condition to the like-new Original Equipment Manufacturer (OEM) condition. Remanufacturing could be an attractive option with the growing vehicle fleet in Sri Lanka. However, most of the existing recovery practices do not fall under the remanufacturing definition. The purpose of this study is to develop a framework to promote automotive remanufacturing among the repairers, re-builders, and other stakeholders. A case study-based approach was used with semi-structured interviews that were conducted physically and remotely. The study derives and presents a remanufacturing closeness factor for each case company by considering product type, process steps, degree of salvage, and performance testing were considered as key elements. Prioritized Internal and external factors were used as construct variables in the framework. Key constructors were core acquisition, skill labour availability, remanufacturing process steps, technology, market knowledge, and policy requirements. The developed framework can be used as a guide to promote the efficient adaptation of remanufacturing.
- 14:45 A Framework to Promote Mould Remanufacturing in Sri Lankan SME
The global mould manufacturing market amounts to USD 26.21 billion in 2020 and is expected to increase to USD 38.62 billion in 2025 at a Compound Annual Growth Rate (CAGR) of 8%. This growing demand for moulds urges to develop sustainable methods to recover used moulds. Remanufacturing of moulds offers a promising solution in the industry which extends the useful life of end-of-use moulds. However, there is a lack of evidence that mould remanufacturing is used to reap its potential benefits in Sri Lankan Small and Medium-sized Enterprises (SME). Literature review and semi-structured interviews were used to establish the current knowledge, identify barriers, and to identify key elements in developing the framework. The paper presents a conceptual framework developed for promoting mould remanufacturing in Sri Lankan SME.
Thursday, July 28 14:30 - 15:30
- 14:30 A Study on Axial Performance of Helical Piles in Residual Soils
Helical piles offer an economical alternative to traditional foundation types such as pad footings, rafts or piles while providing required support to the structure. This paper presents an analysis on the axial performance of helical piles through in-situ static load tests, theoretical studies, numerical modelling, and empirical relationships. Based on results, suitability of using empirical factors given in literature to determine axial pile capacities or to find installation torque needed in achieving design loads is checked. In this study, 19 static load test results were compared against results from other capacity evaluation methods and suitable values were suggested for empirical factors under different subsoil conditions if values given in literature does not provide accurate estimations for axial pile capacities.
- 14:45 Effect of a Shear Key on the Behaviour and Stability of Cantilever Type Retaining Walls
Cantilever retaining walls are the commonly used retaining wall type. Shear keys are the structures incorporated in the cantilever retaining walls to increase their resistance to sliding. In the current study, the optimal location and depth of the shear key are investigated. A theoretical approach based on limit equilibrium and numerical modeling have been adopted in the analysis. Limit equilibrium analysis was carried out using the Excel spreadsheet application. The values of Factor of Safety against sliding and overturning, varying with the shear key's depth and location, were presented as graphical representations. Finite Element Analysis was carried out using PLAXIS 2D software to analyze the variation of the overall stability with the increasing depth of the shear key. The limit equilibrium analysis observed that utilizing a shear key enhances the stability of the retaining wall against sliding. It was also found that the increased depth of the shear key reduces the stability of the retaining wall against overturning, and the optimum location of the shear key is at the heel of the wall base. Results from the Finite Element Analysis show that the retaining wall's overall stability increases with the increase in the depth of the shear key.
- 15:00 Effect of Dynamic Compaction on the Compressibility Characteristics of Municipal Solid Waste, Under the Saturated and Unsaturated Conditions
The scarcity of land suitable for new developments in urban areas is a growing problem in many countries. In Sri Lanka, open dumping has caused unsanitary landfills within major cities, and it is economically, socially, and environmentally desirable to rehabilitate them. Ground improvement is a significant step in the rehabilitation of landfills, and dynamic compaction (DC) is a commonly used method in treating heterogeneous fill materials such as municipal solid waste (MSW). In this study, MSW samples obtained from the Meethotamulla landfill site, Sri Lanka, subjected to DC under both saturated and unsaturated conditions, were tested using the Rowe cell apparatus. Their compressibility characteristics were established under four conditions: saturated-compacted, saturated-noncompacted, unsaturated-compacted, and unsaturated-noncompacted. The results of the analysis indicated that the improvement of density and compressibility characteristics of MSW due to DC is greater under the unsaturated condition. In addition, the results were compared with that of preloading. It was found that preloading is more effective in improving the compressibility of MSW under both saturated and unsaturated conditions.
- 15:15 Use of the Concept of Capillary Barriers to Optimize the Support Systems of Deep Vertical Excavations in Unsaturated Soils
In deep excavations, it is necessary to guarantee stability against catastrophic failure and to ensure that the deformations in the surrounding are within acceptable limits. Excavations done above the groundwater table can be supported with simple structures such as soldier pile walls. But the stability of the structure is affected by the infiltration of rainwater. If the infiltration of rainwater can be reduced the construction of deep vertical excavation support system can be optimized. A Capillary Barrier (CB) which consists of a fine layer lying on top of a coarse layer at the ground level can cut off the infiltration into the lower layers. In this research study, initially attempts were made to establish the critical parameters through parametric studies. A laboratory model of a Capillary Barrier was constructed with instrumentation and a rainfall pattern was applied. Experimental results were verified with GeoStudio, 2012 SEEP/W software and there was a very good agreement. A deep excavation supported by a soldier pile wall in an unsaturated soil was modelled thereafter with Midas GTS-NX 3D software and the effectiveness of the capillary barrier in optimizing the design of the support system during a prolonged rainfall was illustrated.
Thursday, July 28 14:30 - 16:15
T4-2-3: Communication and Signal Processing, Image Processing and Computer Vision, Electronics, Biomedical Engineering & Instrumentation
- 14:30 Shadow Removal for Documents with Reflective Textured Surface
An increasing number of institutions are converting from traditional verification to online digital verification of user documents. In Sri Lanka, this requires clean digital images of documents such as the NIC, driver's license etc. which often have background textures and reflective surfaces. Due to human error, uneven natural light and reflectance properties, such document images contain cast shadows which pose a difficulty to further processing. The NIC dataset itself has some properties unique to a document image, i.e., dark letters on a light background, and some properties unique to a natural image, i.e., background object textures. Therefore, the target domain or nature of dataset itself is a novelty. Because previous open-source research for our use case is not already available, we have experimented our dataset with already existing state of the art models in both shadow removal for document images and shadow removal for natural images. Our proposed model reflects the typical backbone architecture for ‘shadow removal models for natural images' when removing shadows while preserving background textures. Our architecture results in an overall quality improvement of 12% and 63% improvement in output resolution when compared with the state-of-the-art architecture in shadow removal for natural images.
- 14:45 Segmentation Based Approach for Off-Line Handwritten Sinhala Word Recognition from Touch Screen Gestures
The traditional way of using pen and paper to take notes is getting over by the touch screen devices. These devices provide more options to the users to enhance their productivity while taking notes. The ability to recognize and validate the words written on the touch screens facilitates further capabilities to the users. Hence, in this paper, we describe a segmentation-based approach combined with an n-gram model for touch gesture written Sinhala word recognition and validation. We compare the results of 6 commonly used machine learning models to find the finest classifier for recognizing individual characters of words. The classifiers are trained to identify 19 different Sinhala characters. Based on the results, Convolution Neural Network (CNN) based word classifier stands ahead of other classifiers.
- 15:00 Study of Stability Variations in Reaction Torque Observer Based Force Controllers
An effective method for determining the environmental impedance is to use a reaction torque observer (RTOB), which is a variant of the disturbance observer (DOB) concept. A robust yet accurate force controller can be developed by implementing both RTOB and DOB. This study examines the potential instability of force controllers based on RTOB. Traditionally, a RTOB-based force controller is examined under the presumption that the two cut-off frequencies for DOB and RTOB should always be equal to one another. But in some circumstances, it fails to maintain stability. The stability of the system is determined by the interactions between the mechanical, environmental, and controller dynamics, which also add to design constraints. There has not been any analysis of unstable scenarios in terms of system dynamics. In this paper, a novel stability constraint is derived as a result of the new stability assessment approach that is proposed. A new stability guideline is also suggested. The simulation results are used to confirm the validity of the proposals.
- 15:15 Deep Learning for Arbitrary-Shaped Water Pooling Region Detection on Aerial Images
Recent rapid development in Unmanned Aerial Vehicles (UAVs) have extensively promoted several types of civilian tasks. In this paper, we propose and compare two different deep learning and convolutional neural network methods to detect and extract the region of water pooling areas, such as gutters, abandoned ponds, tires, and other water retaining areas on rooftops, using UAVs based aerial images. The performance comparison between the YOLOv4 algorithm and the Mask-RCNN algorithm was explored in the case study to identify the best deep learning method for detecting these uneven regions of water pooling. Experimental results show that the Mask-RCNN approach efficiently detects these uneven areas in an aerial image while simultaneously generating a high-quality segmentation mask for each instance. On the other hand, YOLOv4 detects the best bounding box for the area of interest. The mean average precision (mAP) scores for Mask-RCNN and YOLOv4 are 71.67% and 57.9% respectively. The Mask-RCNN system has shown promising results on test images and video clips. Such real-time detection systems would eventually help to identify mosquito breeding sites to assist the dengue eradication as well as to identify suitable water resources for daily uses, thereby facilitating a better community health system.
- 15:30 Sinhala Fingerspelling Sign Language Recognition with Computer Vision
Computer vision based sign language translation is usually based on using thousands of images or video sequences for model training. This is not an issue in case of widely used languages such as American Sign Language. However in case of languages with low resources such as Sinhala Sign Language, it's challenging to use similar methods for developing translators since there are no known data sets available for such studies. In this study we have contributed a new dataset and developed a sign language translation method for the Sinhala Fingerspelling Alphabet. Our approach for recognizing fingerspelling signs involve decoupling pose classification from pose estimation and using postural synergies to reduce the dimensionality of features. As shown by our experiments, our method can achieve an average accuracy of over 87%. The size of the data set used is less than 12% of the size of data sets used in methods which have comparable accuracy.
- 15:45 Performance Evaluation of UAV-Assisted Millimeter Wave NOMA Networks
Mobile users may experience frequent service outages or poor quality of service in rural areas due to the scarcity of base stations in the proximity. Therefore, a cost effective and flexible solution is introduced in this paper with unmanned aerial vehicles (UAVs) and terrestrial base stations (TBSs) coexisting under a stochastic network with the combination of millimeter waves and non-orthogonal access (NOMA) methods. This is achieved by deploying both the UAVs (millimeter wave frequencies) and TBSs (sub-6 GHz frequencies) in the same system, and selecting the transmitter based on a user association scheme. The maximum SINR and the closest transmitter user association schemes are compared using extensive simulations to find out the best performing scheme in terms of the outage probability and the achievable downlink rate. The results show that the closest transmitter user association policy results in lower outage and higher downlink rates for UAV-assisted millimeter wave NOMA Networks.
- 16:00 Development of a Bicondylar Surface for a Biomimetic Knee Joint Capable of 3D Motion
The knee is a major joint that is capable of 6 degrees of freedom (DoF) motion. In this paper, we present a biomimetic design of a bicondylar knee joint capable of 3D motion. The development of bicondylar surfaces is limited by the absence of accurate condylar surface development methodologies. Hence, this paper proposes a novel methodology, to obtain accurate bicondylar surfaces. The proposed method is used to develop a physical knee joint model. This knee joint model is experimentally evaluated using a model lower limb test setup (replicating the ankle, knee, and hip). The squatting motion of a human is replicated using this test setup. The hip motion of a healthy male test subject is recorded via image capture, and the hip joint of the test setup is actuated to follow this path. The computational model of the knee joint is used to predict the expected motion path during squatting, and the experimental result is compared against it. The results show RMSEs of less than 2.4 mm and 5.78 mm for anterior-posterior and inferior-superior displacements, respectively. Hence, it shows that the proposed bicondylar surface development methodology can be used to develop a biomimetic knee joint capable of 3D motion.
Thursday, July 28 15:30 - 17:15
- 15:30 Establishing Initial Hypothetical PLS-SEM for the Challenges of Converting Existing Office Buildings to Green Buildings in Sri Lanka
Sri Lanka is progressively moving towards sustainability concepts to achieve a circular economy and sustainable development goals. The challenges to converting existing offices to green buildings in Sri Lanka assed in 50 low-rise office buildings in Colombo through 150 decision-makers. There were 25 challenges identified initially from a systematic literature review, and the challenges were further reduced to four main components in the PCA to reduce complexity. The initial hypothetical PLS-SEM model was established to identify the main challenges and the others that fall under it. The four main challenges can be categorised into; Industry and Technology Environment (ITE), Corporate issues (CI), Government Interventions (GI), and Stakeholder Awareness (SA).
- 15:45 A Simulation Study on Novel Clay Secondary Walling System for Indoor Cooling: A Performance Assessment
Climate change is a defining issue of our times. It has an influence on humans and the ecosystem because of variations in the earth's temperature and rainfall patterns. As people spend the majority of their time indoors, changes in the climate can affect the quality of the outdoor air that seeps into their surroundings and raises the temperature of the air. Even though passive cooling options are available to mitigate this issue, they have been shown to be insufficient to meet the anticipated need. To achieve the desired level of comfort, residents of the building must use active cooling systems. The widely available active cooling systems are vividly demonstrated to be unsustainable and energy-intensive. Thus, this study aims to evaluate the use of energy-efficient and cost-effective techniques in a building by encouraging the use of natural materials, such as clay panels, to increase thermal mass and use hybrid ventilation techniques to reduce energy consumption. The results show the system's effective and efficient configuration of 36 panels and 3 fans to create a comfortable indoor living environment.
- 16:00 Establishing the Relationship Between Indoor and Outdoor Temperature of an Existing Office Building Using Hybrid Physics Based and Data Driven Models
Building cooling energy demand accounts for a significant fraction of the global energy demand. This is significant in hot and humid countries especially in the South Asian region where the electricity infrastructures are at risk due to increasing demand for building cooling due to various factors such as global warming and growth of population. Although this risk has been identified, limited research has been conducted in energy demand predictions in these climatic zones. Nevertheless, the use of data driven modelling for demand predictions of buildings is becoming popular around the world. Hence, this paper focuses on developing a model to predict indoor temperature from outdoor conditions to estimate the cooling energy demand. The model presented is a hybrid model which is a combination of physics based and data driven models. The model was trained and validated for an existing office building in a tropical climate zone. Model parameters were calculated using different surveys. The developed model has been used to calculate the cooling energy demand of the selected zones. It was observed that the demand increase is dependent on various zone envelope properties (window area, floor area etc.) and these zones show a significant correlation between indoor and outdoor conditions.
- 16:15 Role of Green Manufacturing Practices on Green Knowledge and Employee Green Behaviour in the Manufacturing Sector in Sri Lanka
The entire world faces severe environmental problems that represent a threat to the planet's existence. Thus, protecting the environment, minimising environmental degradation, and safeguarding the earth's natural resources are crucial. Hence, Companies in the manufacturing industry need to implement green initiatives to adhere to the initiatives of global environmental standards. The success of these companies' efforts is mainly determined by how employees participate in the implementation process. Moreover, manufacturers worldwide are being pushed to embrace green manufacturing practices by raising the environmental knowledge of employees. Thus, this study investigated the direct and indirect impact of green manufacturing practices (GMP) on employee green behaviour (EGB) along with employee green knowledge (EGK) as the mediator of this study. Four hypotheses were formed to support the arguments based on an exhaustive literature review. The sample size was 350 employees working in the furniture, paper and paper products in Sri Lanka. Structural equation modelling (SEM) is used to test the hypotheses. The results revealed a positive impact of GMP on EGB and EGK. Further, EGK influenced EGB as well. Though EGK acts as a mediator between GMP and EGB, it is not particularly powerful.
- 16:30 Selection of Phase Change Materials for High Temperature Latent Heat Thermal Energy Storage for Concentrated Solar Power Plants
Concentrated Solar Power (CSP) is one of the most promising options among emerging renewable energy technologies. Thermal energy storage can be incorporated into CSP plants to improve dispatchability. Thus, the development of high-temperature Thermal Energy Storage (TES) materials is essential to enhance the performance of CSP plants. Phase Change Materials (PCM) show favourable characteristics to be used as the working material in this application. This paper addresses the selection of appropriate storage materials that have desirable properties for thermal energy storage in CSP applications, considering the cost and volume per unit of thermal energy storage. A three-stage screening process based on melting temperature, latent heat of fusion, cost, thermal conductivity and storage volume criteria was used to select the most economical and thermo-physically feasible materials from a list of 25 materials. Accordingly, Na2CO3 + Li2CO3 (56:44), Li2CO3 + K2CO3 (28:72), Li2CO3 + K2CO3 (35:65), NaF + KF + K2CO3 (17:21:62), LiCO3 + Na2CO3 + K2CO3 (20:60:20), Li2CO3 + Na2CO3 + K2CO3 (22:16:62), K2CO3 + Na2CO3 (51:49) 8 PCMs were selected as the best materials to develop high temperature TES for CSP plants. Using these PCMs as storage materials, cost-effective TES can be developed to deliver technical and economic benefits.
- 16:45 Fuel Stacking and Stove Choice Decisions: A Discrete Choice Model of Sri Lankan Household Preferences for Clean Cooking Solution
Transition from non-clean cooking fuels to clean cooking fuels is a sustainable development requirement which needs to be addressed at a household level. Household decisions play a crucial role in terms of cooking transition and preference towards product specific factors. Developing countries need to address this problem immediately as it faces socioeconomic challenges which are complex. The presence of improved consumer products according to consumer's preference for cooking fuels in these regions acts as a major motivator for cookstove adoption. Hence, understanding household preference for clean cooking solutions is useful for policy makers and organisations involved with the cooking fuel supply chain and product development. In order to better understand household decision-making in Sri Lanka, a stated preference survey and discrete choice model were constructed. With the exception of price and usage cost factors for the dirty stacking households, the study indicated that the product-specific factors explored have a significant impact on stove and fuel choices. Instead, energy switching, in which LPG and electricity supplement and increase a household's energy portfolio, is more likely.
- 17:00 Fuel Efficiency and E-Mobility Policy Development in Sri Lanka
Transport is one of the sectors targeted to reduce CO2 emissions and where adaptation measures are needed to reduce the global vulnerability to climatic changes. This research was designed to understand the limitations of conducting an impact analysis of policy options for vehicles' fuel economy and discuss opportunities for fuel economy baseline and policy development including government foresight and global commitments. This paper proposes a two-stage methodology namely fuel economy baseline and System Dynamics (SD). This amalgamated framework allows policymakers to review and analyse the impacts and relationships of past and current fiscal policies on energy-efficient vehicles. Empirical evidence suggests that government intervention and leadership will be a major requirement for developing a baseline for fuel economy. Public awareness and decision making should be considered in policy and planning because people do not easily link policies with fuel economy. These results would be useful in understanding consumer behaviour and market responses to fiscal policies that will impact the vehicle fuel economy and emissions in Sri Lanka.
Thursday, July 28 15:45 - 17:15
- T1-2-4.1 15:45 Quasi-Static Deployment Simulation of a Kapton Polyimide Creased Unit
When thin-film membranes are folded, the resulting creases alter the physical state and material properties of the overall membrane structure. Characterising the mechanics of these creased membranes plays a significant role in predicting their deployment force and deployed configuration. According to previous studies, the hinge response at a crease during the deployment could be best characterised by a rotational spring, whose nature of stiffness should be determined via physical experiments. In this study, a quasi-static deployment simulation for a Kapton polyimide creased unit was carried out using Abaqus/Explicit package to study the applicability of crease idealisation in the presence of an intersection of creases. Crease stiffness obtained for a single creased specimen from a displacement controlled experimental study developed by previous researchers was implemented as the rotational spring stiffness in the numerical model. The accuracy of the numerical study was verified by conducting the same experimental study for the creased unit. The simulation developed in Abaqus/Explicit environment was able to capture the deployment response observed in the physical experiments, in terms of maximum deployment ratio and shape on incorporating the effect of gravity to the simulation.
- T1-2-4.2 16:00 Assessment of the Optimum Dimensions for Cobble-Type Paving Blocks Using Finite Element Modeling
A numerical model was developed to investigate the deflection of permeable interlocking concrete blocks. In this study, the acceptance of paving blocks with extensive plan areas was tested. ABAQUS finite element modelling software which is commercially available was used and a static, linear perturbation analysis was carried out. Three alternative block dimensions were determined according to the guidelines provided in ASTM C936 and were modelled. Mesh sensitivity analysis was carried out on each alternative to identify the optimum global element size for each model. Although all three tested models resulted in vertical deformations less than the threshold, the results indicated a positive association between the exposed plan area and the vertical deformation. Finally, it can be concluded as the SLS 1425 recommended paving block dimensions resulted in the most favorable results.
- T1-2-4.3 16:15 Experimental Study on Tensile Strength Degradation of Carbon Fiber Reinforced Polymer (CFRP) Composite in Alkaline Environment
Carbon fiber reinforced polymers (CFRP) composites are being extensively used in the civil engineering industry in recent years because of their superior characteristics. CFRP composites comprise carbon fibers that are resistive to corrosion and epoxy resin matrix which is highly vulnerable to moisture and corrosive ions. Therefore, the durability of these composites in harsh environment conditions especially in the alkaline environment still needs to be studied. Wastewater treatment plant tanks, sewage networks and marine structures using this technology to strengthen structures is a great challenge as alkaline ions present in these environments possess a serious threat to the CFRP system. In this study, a comprehensive accelerated program was conducted to assess the tensile capacity deterioration of CFRP composite subjected to an alkaline solution with a pH value of 12.6. Microstructure analysis was carried out using Scanning Electron Microscope (SEM) to identify in-depth material disintegration. A maximum tensile capacity reduction of 11.5% was identified and SEM images revealed damage in the resin matrix because of moisture and alkaline ion intrusion.
- T1-2-4.4 16:30 An Alternative Method to Reduce the Construction Cost and the Reinforcement Usage of the Rigid Pavement near the Toll Plaza in Expressways
In expressways, toll plaza structure is a conspicuous structure, where vehicles frequently brake and accelerate within a small distance. As a result, the pavement deteriorates at a higher rate compared to normal bituminous pavement. Hence, toll lanes near toll plazas are constructed as heavy reinforced concrete rigid pavements. In Sri Lanka, the same technique is used for rigid pavements near expressway toll plaza structures. Due to the high cost of this method, the objective of this research is to present a cost-effective way with acceptable efficiency by comparing methods and technologies that other countries use to construct rigid pavement in toll lanes. To achieve this objective, the used design methods and the material cost of the Colombo-Katunayake expressway at Peliyagoda and Seeduwa toll entrances, Dambokka and Kurunegala toll entrances in the Northern expressway are discussed in this study. The study revealed that the replacement of reinforced concrete pavements in the above toll gates with Ultra-thin continuously reinforced concrete pavement can decrease the material cost by 7.97% at Peliyagoda, 36.08% at Seeduwa, 5.66% at Dambokka, and 5.48% at Kurunegala. Used pavement design and the proposed ultra-thin continuously reinforced concrete pavement are analyzed using the Finite Element Analysis through ABAQUS 2020 software.
- 15:45 Chitosan-Graphene Oxide Composite Membrane for Methylene Blue Removal
Textile wastewater accommodates many toxic organic contaminants which could potentially threaten the ecosystem if left untreated. Methylene blue is a toxic, non-degradable, cationic dye which is reportedly found in significant amounts in the textile effluent stream as it is widely used to dye silk and cotton fabrics. This study reports an investigation of methylene blue removal using a composite membrane fabricated using chitosan- graphene oxide. The fabricated composite membrane was characterized using Scanning Electron Microscopy, FT-IR Spectroscopy, Raman Spectroscopy, UV-vis spectroscopy, and X-ray Diffraction. The isotherm modelling conducted confirmed a maximum adsorptive capacity of 179 mg/g which was well fitted with the Langmuir isotherm model indicating a homogenous monolayer adsorption.
- 16:00 Influence of Repeat Unit Size on the Auxetic Effect of Foldable Weft Knitted Fabrics
General phenomenon of engineering materials is to reduce the width when stretched. The auxetic materials expand in the lateral direction when stretched and contract when compressed, giving a negative Poisson's ratio. This exceptional behaviour of auxetic materials offers great benefits such as enhanced fracture toughness, superior indentation resistance, and better energy and sound absorption. Auxetic knitted fabrics have a high potential to be employed in areas of tissue engineering, adaptive clothing, and various fashion applications. The inherent curly configuration of single jersey weft knitted fabrics makes it an ideal candidate for creating foldable auxetic fabric structures. Therefore, a foldable weft knitted structure is selected for further investigation. Various foldable knitted structures were developed by changing the repeat unit size and evaluated for the folding properties. The highest negative Poisson's ratio reported was - 0.73 from the 24x24 (courses x wales) repeat unit.
- 16:15 Copper Nanoparticle Synthesis on Plasma Treated Poly(lactic) Acid Nonwoven Fabrics
day by day. With the covid-19 pandemic situation there is an attention for antibacterial and antiviral nonwoven fabrics which can be used towards development of personal protective wear. To reduce the environmental pollution cased by disposable, and non-biodegradable polymer made personal protective wears can be replaced by biodegradable polymers like poly(lactic) acid (PLA), which is quite similar to polypropylene, but biodegradable. In this study non-thermal plasma treatment method is used to increase the surface reactivity of PLA nonwoven polymer surface. On the activated nonwoven surface copper nanoparticles are in-situ synthesized by chemical treatments. After 30 minutes of plasma treatment better copper nanoparticle distribution and higher yield was achieved. Fourier transformed infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used to characterize the treated PLA nonwoven fabric surfaces.
- 16:30 Numerical Study to Investigate the Pressure Propagation Patterns by a Compression Sleeve with Miniaturised Air-Bladders
Chronic venous disease (CVD), the most prevalent vascular disease affecting to the lower extremities, is regarded as any functional or morphological abnormalities of the venous system. Compression therapy, either active or passive is currently regarded as the cornerstone of treatment for all CVD related complications. However, most of the existing textile solutions have major limitations of applying uniform pressure around the lower limb circumference which was overcome by applying a radial force in response to the pressure exerted by an air volume trapped inside a miniature bladder. Hence, this article used numerical simulations to investigate the propagation of pressure on the skin, fat, and muscle layers applied by hexagonal shaped mini-bladders. The results of this study revealed that 40% of the internal pressure of the bladders successfully transmitted through the skin layer, and a slight increase of pressure was recorded along the thickness of the skin layer while it was decreased in fat and muscle layers. Moreover, the highest percentage of pressure drop was recorded along the muscle layer.
Thursday, July 28 17:30 - 18:00
Friday, July 29
Friday, July 29 8:00 - 19:00
Zoom links to workshop participants have been emailed to the registered email address.
Friday, July 29 8:30 - 13:00
Global and Local supply chains were clearly impacted as a result of COVID-19 and the ensuing consequences of the pandemic in markers around the world with a special emphasis on production. Collectively, these events served as a true litmus test for supply chain resilience. Organizations in Sri Lanka found themselves quickly needing to address critical dependencies in their supply chains. The pandemic has forced organizations to prioritize supply chain resilience. In addition to close supplier relationships, increased digitalization, advanced technologies, machine learning and artificial intelligence will play an increasingly important role in building supply chain resilience in the post-pandemic world. To support the organizations in mapping their supply chains, identifying risks, reviewing their network and innovating via technologies, a solid understanding of modelling and simulation using programming languages/software such as Python, Cytoscape, etc. are required. This workshop is an initial step towards fulfilling that need. The delivery will be highly interactive, and it will provide the participants with the necessary hands-on skills.
Friday, July 29 8:30 - 16:30
The Centre for Intelligent Transport System (CITS) of the University of Moratuwa caters to the academic and industry gaps in transportation due to the absence of a platform for individual sector experts to work together for the betterment of transportation. The Centre has been successful in bringing together different academic disciplines of the university for collaborative research developments and industrial projects both with national and international partners addressing different aspects of transportation engineering. Two major projects that have been successfully carried out by CITS are the "Multidisciplinary Transport Development Project" and "Sustainable & Efficient Electric Mobility System in Sri Lanka". Under these projects many inventions and outcomes have been achieved and sharing these findings with the relevant stakeholders is important for successful implementations
Friday, July 29 8:30 - 11:30
Data engineering has contributed immensely to the advancement of biology and medicine. Various AI-based solutions are proposed and implemented for decision-making. However, widespread adoption of AI as a frequent resort in decision-making that has tangible impacts on patient well-being is still far from achieving its potential due to the controversy of outsourcing the health and medical decision-making processes to black-box AI methods. Therefore, fairness and explainability are two factors that are desirable by biologists and medical practitioners. Recent research has focused on producing AI methods that are both transparent and can cater to improving societal equity in their respective domains. With this in mind, we consider the advances made in fairness and explainability of AI in medical and biological applications. We conceive it vital that they are considered in generalisable engineering solutions. Accordingly, this workshop focuses on methods suitable for developing fair and explainable AI-based solutions for biology and medicine.
Friday, July 29 13:00 - 17:30
Climate change and rapid urbanization with growing population have prompted an emerging interest on construction industries to include more sustainable practices. To accomplish a net-zero carbon building stock in 2050, direct and indirect building CO2 release needs to be assessed and quantified. Thus, the assessment of global warming potential of buildings, through life cycle assessment, taking into account both the processes and materials, to promote the use of more sustainable construction materials and processes is timely. Different techniques associated with sustainability assessment of built environments will be discussed through lectures and interactive activities. An introduction to the life cycle assessment of built environment will be given. Different life cycle assessment tools available to calculate the global warming potential of built environment will be shown with examples. The main challenges associated with the use of tools developed in other countries for such assessment will be highlighted. Finally, there will be a hands-on session to demonstrate the use of a locally developed tool to assess the Global Warming Potential of built environment.
Friday, July 29 13:30 - 17:30
Computational Fluid Dynamics (CFD) has now become a common tool for modelling heat and fluid flow applications in many engineering disciplines. Obtaining accurate results through proper use of CFD requires a solid understanding of underling modelling principles with technical know-how gained through experience. The proposed workshop aims to disseminate the required basic theoretical understanding and technical know-how among researchers of various disciplines. The workshop is designed to be largely with hands on sessions running through a full day to solve several real-life engineering problems. As the main outcome of the workshop, it is expected to promote the interdisciplinary collaborations through research on multidisciplinary, multi-physics CFD modelling exercises.
Friday, July 29 13:30 - 16:30
W2: Workshop2: Workshop on Applying ‘Time-of-day' Concept in Transport Demand Modelling Using Cube Voyager Software
Modeling and simulation is the key for transport planning and transport engineering. With the ever growing motorization, moving goods and people efficiently becomes more challenging for every city. Wrong policy decisions made to face those challenges create huge unnecessary costs to society, while most of them are irreversible. Therefore, such decisions must be made carefully with a scientific approach to make sure the solutions are sustainable. In order to make accurate decisions faster with no human error, the use of computer aided modelling and simulations are being heavily used around the world. One such world popular computer application is CUBE Voyager by Bentley that will be used in this workshop. The capabilities of CUBE Voyager help participants to make better and accurate models enabling better decision making.
W8: Workshop8: ‘Lifting the Lid': Developing Academic Literacy as a Means of Supporting English Medium Degree Programmes
This workshop focuses on the development of the Academic Literacy (AL) of undergraduates as a means of ensuring academic success in English Medium Degree Programmes (EMDPs) in the state universities of Sri Lanka. The number of EMDPs is steadily increasing in Sri Lankan Higher Education (SLHE), but there is a lack of awareness and/or lack of attention to the concept of AL, which has the potential to minimise the struggle faced by undergraduates as they transition from school to university education. The scope of this workshop is firstly to help the participants identify what academic literacy is, its positioning in English Medium Instruction (EMI) settings, and its importance in EMDPs; secondly, to discuss and share practical examples of successful implementation of AL; and finally, to discuss challenges and solutions to successful AL development. This workshop will provide the participants with a hands-on experience of discovering the concepts and practices of AL to be applied in their respective disciplinary contexts for successful facilitation of undergraduate education
Friday, July 29 16:15 - 21:30
This workshop aims to raise awareness of possible pitfalls of existing Machine Learning (ML) algorithms among practitioners and users and emphasize the importance of developing trustworthy ML algorithms. To achieve this objective, the workshop will bring together international experts from ML interpretability, fairness, robustness, and verifiability to discuss the progress so far, issues, challenges, and the path forward
Program last updated on Aug 9, 2022 09:42 UTC