SLIIT International Conference on Engineering and Technology [SICET]

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SLIIT International Conference on Engineering and Technology is organized by the Faculty of Engineering. SICET welcomes submissions from various disciplines, focusing on emerging trends in Engineering, Technology, and Applied and Natural Sciences. The conference will encompass research in theory, practical applications, and education. This event offers a unique platform for academics, student researchers, and industry practitioners to present innovative ideas and engage with professionals from diverse engineering fields

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Open Access
A Comparative Study on TiO₂/Graphite–PEG and Graphite/Carbon Fibre- Paraffin Shape Stabilized Phase Change Materials for Thermal Energy Storage Applications
(Faculty of Engineering, 2025-09-09) Dananjaya, V; Wen,Q; Abeykoon, C
Shape-stabilized phase change materials (SSPCMs) are promising candidates for latent heat thermal energy storage systems due to their high energy density and ability to prevent leakage during phase transitions. This study presents a comparative analysis of two SSPCM systems: TiO₂/graphite–polyethylene glycol (PEG) and graphite/carbon fibre/graphene–paraffin composites. Both composites were prepared by vacuum-assisted infiltration of molten PCMs into porous expanded graphite networks, with the addition of functional fillers to enhance structural integrity and thermal stability. Scanning electron microscopy (SEM) revealed distinct microstructural features for each system; TiO₂ nanoparticles were uniformly dispersed within the PEG matrix and anchored onto graphite surfaces, while carbon fibres and graphene nanoplatelets formed a hierarchical interconnected network within the paraffin-based composites. Differential scanning calorimetry (DSC) demonstrated that both systems preserved high latent heat storage capacities with slight shifts in phase transition temperatures compared to pure PCMs. Thermogravimetric analysis (TGA) showed improved thermal stability of the SSPCMs relative to neat PCMs, with filler composition significantly affecting degradation onset temperatures. In TiO₂/graphite–PEG composites, DSC analysis showed melting temperatures of 61.4-62.7 °C and solidification temperatures of 53.1-54.0 °C, with latent heats of 185-210 J g⁻¹ depending on TiO₂ content. Graphite/carbon fibre/graphene–paraffin composites exhibited melting temperatures of 54.8-55.6 °C and solidification temperatures of 48.9-49.7 °C, with latent heats of 140-160 J g⁻¹. Thermogravimetric analysis revealed improved degradation onset temperatures: TiO₂/graphite-PEG composites showed higher thermal stability compared to pure PEG, while carbon fibre/graphene–paraffin composites exhibited enhanced thermal resistance relative to pure paraffin. The TiO₂/graphite-PEG composites exhibited higher latent heat capacities and enhanced thermal resistance, whereas the graphite/carbon fibre/graphene–paraffin composites provided superior mechanical reinforcement and phase change reliability. These findings offer insight into the design optimization of SSPCMs tailored for specific thermal management applications.
Open Access
A Cost-Effective Battery Retrofit for Non-Hybrid Grid-Tied PV Systems to Reduce Solar Energy Loss During Grid Outages
(Faculty of Engineering, 2025-09-09) Jayamanne, N
Conventional grid-tied, non-hybrid photovoltaic systems disconnect from the utility grid during outages, resulting in complete solar energy loss despite continued solar generation. This paper proposes a cost-effective retrofit solution that enables energy harvesting and storage during such outages without requiring inverter replacement or voiding manufacturer warranties. The proposed retrofit integrates three blocking diodes, a two-pole DC magnetic contactor, a DC relay, a bidirectional maximum power point tracking (MPPT) DC–DC battery charger, and a microcontroller-based supervisory controller. Under normal grid-connected conditions, the retrofit remains electrically isolated to preserve the inverter’s original operation. During grid outages, available solar energy is redirected to charge a battery through the bidirectional charger. At night, the stored energy is discharged via controlled current injection into one of the inverter’s MPPT inputs through the diode-protected pathway, enabling up to 12 hours of energy utilization depending on local night duration. This approach mitigates solar energy loss during grid failures, eliminates the need for costly hybrid inverter upgrades, and offers a scalable retrofit pathway for residential and small-commercial PV systems.
Open Access
A Data-Driven Approach to Predicting Ischemic Heart Disease Risk in Monaragala: Integrating Lifestyle and Symptom Factors with Machine Learning
(Faculty of Engineering, 2025-09-09) Meddepola, M.A.R.L.; Wickramasinghe, B.M.G.S.T.S.K.
Ischemic Heart Disease (IHD) remains a leading cause of mortality worldwide and presents a critical challenge in underserved rural areas such as Monaragala, Sri Lanka. Traditional IHD prediction methods predominantly depend on clinical diagnostics like ECGs and blood tests, which are often unavailable or inaccessible in such regions. This study aims to bridge this gap by developing a machine learning-based prediction model that utilizes only lifestyle and symptom-related data, eliminating the need for invasive clinical procedures. A dataset comprising lifestyle habits (e.g., diet, smoking, alcohol use, exercise) and symptom indicators (e.g., chest pain, fatigue, dizziness) was collected via surveys. Feature selection using Logistic Regression identified the top eight most relevant predictors. Five machine learning algorithms, Logistic Regression, K-Nearest Neighbors, Support Vector Machine, Decision Tree, and Random Forest, were trained and evaluated. Among them, the Random Forest model achieved the highest performance with an accuracy of 83.5%, precision of 0.86, recall of 0.78, and F1- score of 0.81, demonstrating strong predictive capability based solely on non-clinical features. In addition, a web-based self-assessment tool was developed to make the model accessible to the public, particularly targeting individuals in rural areas with limited healthcare access. The tool enables users to input basic lifestyle and symptom information and receive a real-time risk assessment. The findings confirm that the model leveraging lifestyle and symptom data can effectively identify individuals at risk of IHD. This approach supports the development of scalable, low-cost, and user-friendly screening tools that can enhance early detection and preventive care, especially in rural and resource-constrained settings.
Open Access
A Numerical Investigation of the Potential of Dimpled Surface Configurations to Improve Aerodynamic and Aeroacoustic Performance of Airfoils
(Faculty of Engineering, 2025-09-09) Fernando, N. N; Nissanka, I; Samaraweera, N
This study investigated the potential of dimpled surface configurations to enhance the aerodynamic and aeroacoustic performance of airfoils. Computational Fluid Dynamics (CFD) simulations were carried out on a NACA 0012 airfoil featuring surface dimples, under flow conditions relevant to low-speed aerodynamic applications such as unmanned aerial vehicles (UAVs), light aircraft, and small-scale wind turbines. The simulations were conducted at a Reynolds number of 700,000 and a Mach number of 0.21, representing typical subsonic operating conditions. Two angle of attack, 5° and 10°, were examined to represent attached flow and near-stall behavior, respectively. Aerodynamic performance was evaluated through lift and drag coefficients, while aeroacoustic characteristics were analyzed using Overall Sound Pressure Level (OASPL) with directivity plots and frequency spectrum analysis based on the Ffowcs Williams–Hawkings (FW-H) acoustic analogy. Key findings indicate that the dimpled configuration enhances flow behavior by increasing lift and reducing drag at a 10° Angle of Attack (AoA), primarily through delayed separation and modified stall onset characteristics. Aeroacoustic analysis showed a noise reduction of 2–7 dB at various receiver positions at a 10° AoA, with reductions varying by observer angle and frequency, confirming the directional sensitivity of noise emissions. These insights contribute to the understanding of passive flow control mechanisms and their dual impact on aerodynamic performance and noise reduction in airfoil design
Open Access
A Numerical Investigation of Valve Timing and Intake Pressure Effects on Performance and Emissions in a Hydrogen Port Fuel Injection Engine
(Faculty of Engineering, 2025-09-09) Wickramaarachchi, I; Nissanka, I. D; Wijeyakulasuriya, S
Hydrogen internal combustion engines (H2ICEs) offer a viable low-emission alternative for decarbonizing transport, especially where full electrification is not practical. Among fueling strategies, port fuel injection (PFI) is particularly attractive due to its compatibility with existing engine platforms and simplicity compared to direct injection (DI). Performance and emissions in hydrogen PFI engines are strongly influenced by valve timing and intake boosting strategies. This study presents a computational framework to investigate the coupled effects of valve timing and intake pressure on the performance, thermal efficiency, and NOx emissions of a hydrogen PFI engine under fuel-lean conditions (ϕ = 0.59). A modified Sandia optical engine geometry was simulated using CONVERGE CFD v4.1, employing detailed chemistry and adaptive mesh refinement. Latin Hypercube Sampling (LHS) was employed to generate 373 design cases that span a wide parametric space. Results show that intake boosting significantly improves performance, achieving a 220% increase in indicated power (up to 43.55 kW) and an 11% improvement in thermal efficiency (up to 48.7%) over the baseline configuration. However, these gains are accompanied by elevated NOx emissions, particularly at higher valve overlaps. Conversely, the configuration that achieved the lowest NOx emissions reduced them by 76% compared to the baseline, albeit at the expense of lower power and efficiency. The three configurations representing the most favorable outcomes for power, efficiency, and emissions within the studied parameter space highlight the inherent trade-offs among these objectives. These results provide practical guidance for calibrating hydrogen PFI engines and establish a solid foundation for future studies incorporating formal optimization methods.
Open Access
A Numerical Investigation of Valve Timing and Intake Pressure Effects on Performance and Emissions in a Hydrogen Port Fuel Injection Engine
(Faculty of Engineering, 2025-09-09) Wickramaarachchi, I; Nissanka, I.D; Wijeyakulasuriya, S
Hydrogen internal combustion engines (H2ICEs) offer a viable low-emission alternative for decarbonizing transport, especially where full electrification is not practical. Among fueling strategies, port fuel injection (PFI) is particularly attractive due to its compatibility with existing engine platforms and simplicity compared to direct injection (DI). Performance and emissions in hydrogen PFI engines are strongly influenced by valve timing and intake boosting strategies. This study presents a computational framework to investigate the coupled effects of valve timing and intake pressure on the performance, thermal efficiency, and NOx emissions of a hydrogen PFI engine under fuel-lean conditions (ϕ = 0.59). A modified Sandia optical engine geometry was simulated using CONVERGE CFD v4.1, employing detailed chemistry and adaptive mesh refinement. Latin Hypercube Sampling (LHS) was employed to generate 373 design cases that span a wide parametric space. Results show that intake boosting significantly improves performance, achieving a 220% increase in indicated power (up to 43.55 kW) and an 11% improvement in thermal efficiency (up to 48.7%) over the baseline configuration. However, these gains are accompanied by elevated NOx emissions, particularly at higher valve overlaps. Conversely, the configuration that achieved the lowest NOx emissions reduced them by 76% compared to the baseline, albeit at the expense of lower power and efficiency. The three configurations representing the most favorable outcomes for power, efficiency, and emissions within the studied parameter space highlight the inherent trade-offs among these objectives. These results provide practical guidance for calibrating hydrogen PFI engines and establish a solid foundation for future studies incorporating formal optimization methods.
Open Access
Adoption Of A Circular Economy Framework In The Design Phase Of The Refurbishment Project
(Faculty of Engineering, 2025-09-09) Abilash, S; Gunarathna, K A N; Kalugala, C.
Sustainable development in the built environment depends on minimizing environmental impact and conserving resources. In refurbishment projects, integrating circular economy (CE) principles during the design stage can significantly reduce waste and enhance resource efficiency. This study presents a tailored CE framework based on the 2D3R model, which emphasizes Design for Disassembly, Design for Adaptability, and the strategies of Reduce, Reuse, and Recycle. The framework was developed through a combination of literature review, expert interviews, and survey analysis to identify drivers and barriers to CE adoption in refurbishment. Key findings highlight the role of digital technologies particularly Building Information Modeling (BIM) in improving material traceability and facilitating lifecycle assessments. These tools support the implementation of circular strategies by enabling better planning and design decisions early in the project. The study concludes that applying the 2D3R approach in initial design phases enhances sustainability, reduces costs, and improves the adaptability and longevity of refurbished buildings.
Open Access
Aeroacoustic Noise Produced from Novel Wind Turbine Rotor Design for Small-scale Applications in Sri Lanka
(SLIIT, 2022-02-11) Perera, M; Bandara, U. H
Growing concerns regarding non-renewable energy sources have driven academic and industrial scholars as well as global superpowers to seek sustainable, greener power generation alternatives. One such prominent renewable substitute is wind power which was initially utilized in harnessing electricity towards the late nineteenth century though archaeological evidence has proved that wind power had been employed for various purposes since predynastic Egypt. Extensive research and development has enabled the efficient operation of multi megawatt wind farms at present though inherent drawbacks still persist, of which aerodynamic noise, also referred to as aeroacoustic noise, is of major concern. This paper details the simulative investigation of the aeroacoustic sound levels produced by an optimized novel wind turbine design intended for the use in small scale applications with medium wind speed conditions in Sri Lanka, using ANSYS Fluent. A transient analysis using the Shear Stress Transport turbulence model was used to obtain the converged pressure fluctuations which subsequently revealed the sound pressure levels via Fast Fourier Transforms at six predetermined locations of interest. The results revealed the presence of acoustic vibrations within the Infrasonic and Low Frequency Noise range with sound pressure levels exceeding one hundred decibels, particularly up to a frequency of twenty five Hertz. Prolonged exposure to elevated levels of low frequency noise has been identified to cause severe discomfort to humans though further conclusive research is required. Finer mesh controls which incorporate minute boundary layer variations during motion and precisely encapsulate the turbine geometry could further improve the accuracy of the results, however this would require adequate computational capacity. The results of this research primarily serve as a basis for identifying possible improvements for the novel rotor design in addition to providing a comparative study for future research, both simulative and empirical, on the aerodynamic noise emissions associated with wind turbines.
Open Access
Affordable and Reliable Video Laryngoscope with Wireless Connectivity
(SLIIT, 2022-02-11) Dassanayake, I; Senanayake, K; Katakumbura, I; Senaviratne, L
Along with the pandemic situation across the world, the resilience of using ordinary medical devices is limited. Also the demand for medical devices which are used to diagnose COVID-related diseases rapidly increased. Taking all these facts into consideration, a new laryngoscope device was developed with exciting functionalities. The proposed device is affordable and comes with remote monitoring capabilities. An ordinary video laryngoscope uses an expensive camera module to capture video streams, and the proposed device uses ordinary USB camera modules which are cheap and affordable. Therefore, it is even possible to replace/discard camera modules each time after investigating COVID-related patients. The proposed USB camera and Laryngoscopic blades can be easily replaced for a very affordable cost. In the proposed system, a real-time video stream can be remotely monitored in multiple displays, including personal mobile devices. Since the live video footage can be streamed across the world, expertise in the field can monitor and consult promptly. This device broadcasts video wirelessly through LAN (local area) and WAN (wide area) networks in real-time. So far, the device transmits live video streams wirelessly with less than 250ms latency on LAN networks, and 500ms to 1000ms latency in WAN networks. An inbuilt rechargeable power supply will power up the device for ~ 45min in continuous use.
Open Access
Analysis And Optimization Of OLSR And AODV Routing Protocols For Highly Mobile Autonomous Aerial Vehicle Networks: Experimental Performance Evaluation In Various Application Scenarios
(Faculty of Engineering, 2025-09-09) Duc Tu, N; Gorbacheva, L; Muthanna, A
Driven by the rapid evolution of Autonomous Aerial Vehicle (AAV) technology, ad-hoc AAV networks are becoming increasingly significant in diverse domains such as telecommunications, security surveillance, search-and-rescue operations, emergency management, precision agriculture, and cargo transportation. Owing to their flexible deployment and tight coordination capabilities, AAVs enable realtime data exchange, unlocking considerable potential for tasks that demand high accuracy and swift response. Nevertheless, their three-dimensional mobility and continuously changing topology impose substantial challenges on the design of suitable routing solutions, because conventional protocols originally developed for Mobile Ad-hoc Networks (MANETs) are seldom optimized for aerial characteristics. This discrepancy underscores the necessity for a comprehensive analysis and optimal configuration that satisfy the stringent requirements of low latency, high throughput, and reliability in mission-critical AAV applications. Against this backdrop, the present study focuses on the analysis and modelling of two widely adopted routing protocols—Optimized Link State Routing (OLSR) and Ad hoc On-Demand Distance Vector (AODV)—in various deployment contexts of ad-hoc AAV networks. By evaluating the performance of these protocols, we identify their advantages, limitations, and possible enhancement directions, and subsequently propose configuration guidelines that deliver improved link quality.
Open Access
Analysis of a Solar Thermal Based Hot Water System for a Non- Residential Application
(Sri Lanka Institute of Information Technology, 2023-03-25) Aslam, M.A.
Industries in Sri Lanka rely heavily on the use of hot water for their day-to-day applications. Industries such as hotels and hospitals utilise electrically powered geysers, while industries such as wood treating factories, garment industries, and paper manufacturing industries rely on boilers to obtain heated water. The rising cost of electricity production and the pollution associated with current power generation technologies in Sri Lanka have led to a need for a water heating framework which focuses on harnessing renewable energy. Since Sri Lanka is located in close proximity to the equatorial belt, solar thermal water heaters were selected as one of the most viable options. In this study, a hospital was selected as the base scenario onto which a solar water heating framework was to be designed for. The framework focused on the feasibility of three collector types, i.e., Flat Plate Collector, Evacuated Tube Collector and Parabolic Trough Collector. Initially theoretical efficiencies of each collector type were determined for the average annual solar radiation in Sri Lanka. Finally, RETScreen simulation software was used to perform sizing analysis of each water heating system, analyse each systems financial viability and analyse the reduction in annual Greenhouse Gas (GHG) emissions.
Embargo
Analysis of Efficiency and TheAdsorptionNature ofMalachiteGreenDye fromanAqueous Solution on activatedCarbonGenerated fromStrychnos potatorum(Ingini) seeds
(SLIIT, Faculty of Engineering, 2024-10) Buthpitiya, B.L.S.K.; Yohan, L. N.; Arachchige, M
Malachite green (MG) is a basic dye with an amino group which is water soluble. This is a higher brilliance dye even in low concentrations. Therefore, MG is used mainly in dyeing for wool, leather, cotton, paper, wood, jute and as an anti-bacterial, anti-fungal, and anti-parasitical agent in aquaculture. The releasing of wastewater with MG from various industries is a huge problem because of the existence of MG in the wastewater causes toxicity for aquatic lives and it enters into the trophic levels of the food chains and causes teratogenic, mutagenic, carcinogenic and tumor-enhancing effects on human beings. Therefore, the major concern of this study is the removal of MG dye from an aqueous solution on activated carbon generated from Strychnos potatorum (Ingini) seeds (ACSP). The ACSP was characterized by Scanning electron microscope (SEM). The batch adsorption studies were conducted to determine the effect of adsorbent dosage, initial MG concentration, contact time and temperature on the removal of MG. The efficiency of the dye adsorption was determined by Pseudo-first order and Pseudo-second order kinetic models. The adsorption nature was determined by the thermodynamic study. According to the results of this study, the maximum removal percentage of MG dye (99.67%) was obtained for 0.20 g of adsorbent per 25.00 mL of MG volume, pH 4, 30 0C, 60 mg L-1 of initial MG concentration and 2 h contact time and Pseudo-second order kinetic model was well fitted to the data. The negative value for the Gibbs free energy change showed the spontaneity and feasibility of this adsorption process.
Embargo
Analysis of Service Quality Expectation of Passengers: Case Study of Colombo Fort Railway Station
(SLIIT, Faculty of Engineering, 2024-10) Jayathilake, M.N; Fernando, S.S.S.; Madushanka, P.G.D.; Sharic, A.H.S
This study investigates passenger perceptions of service quality at Colombo Fort Railway Station using the SERVQUAL model, focusing on five key dimensions: tangibility, reliability, responsiveness, assurance, and empathy. By examining demographic characteristics such as gender, age, income, frequency of use, trip purpose, and time of travel, this research aims to identify significant differences in service quality expectations among diverse passenger groups. Data were collected from 300 passengers through a structured survey and analyzed using t-tests and ANOVA. The findings highlight critical areas for improvement, including enhanced schedule adherence, improved communication, and better maintenance of station facilities. Notably, the study reveals that daily and weekly commuters report lower satisfaction levels with train punctuality compared to occasional users, while older passengers express higher satisfaction with emergency response and lost item retrieval services. These insights provide valuable recommendations for Sri Lanka Railways to enhance service quality, thereby increasing passenger satisfaction and loyalty. The study underscores the importance of tailored service improvements to meet the specific needs of different passenger demographics, contributing to a more efficient and reliable railway system in Sri Lanka.
Open Access
Analysis of Thermal Performance of Shell and Tube Heat Exchangers: A Correlation and CFD Based Approach
(Faculty of Engineering, 2025-09-09) Ushettige,S.A.P; Wimalsiri, W.K.; Hikkaduwa, H.G.S.
Shell and tube heat exchangers are devices which are widely adopted in thermal systems for the transfer of thermal energy due to both performance and reliability factors. Given their application in systems that are energy intensive, the design and sizing of these devices have become a widely growing field. Traditionally, empirical correlations which were based on experimental results were used for thermal sizing and design. This was replaced by computational fluid dynamics (CFD) modelling given its ability to model and visualize flow, expanding the horizon of possibilities for design and performance optimization. As of recent, CFD has been combined with numerical methods such as non-linear least squares regression to develop correlations which can predict the thermal performance based on the input design parameters. However, the application of this integrated method for shell and tube heat exchangers is limited. This study will model a single pass TEMA E-type shell and tube heat exchanger using ANSYS Fluent ®. CFD simulations are used to explore the effect of turbulence on thermal performance by varying both the inlet mass flow rate and the central baffle spacing. As steady state simulations are conducted for four models of six, eight, ten and twelve baffles. The results of CFD modelling are then combined with non-linear least squares regression in the MATLAB Curve Fitter Toolbox ® to develop four sets of correlation in the form of 𝑁𝑢 = 𝐶. 𝑅𝑒𝑎. 𝑃𝑟𝑏. Reasonably confident results were obtained in the final fitted data, however, relatively high 95% confidence interval widths were evident for certain fitted coefficients leaving space for improvement in the model. The study highlights that combining CFD with tools such as nonlinear least squares regression aids both engineers and designers in the thermal design process of shell and tube heat exchangers eliminating the need to limit design based on empirical correlations.
Open Access
Application of Peak Over Threshold Approach to Model Extreme Motor Insurance Claims: A Case Study
(Sri Lanka Institute of Information Technology, 2023-03-25) Appuhamy, P.A.D.A.N.; Borelessa, N.K.; Ekanayake, E.M.P.
Prior to the economic recession in Sri Lanka, the motor insurance business grew significantly due to the excessive importation of vehicles. More vehicles on the road and reckless driving increase the risk of extreme claims, which creates a negative impact on the industry. In order to mitigate this issue, researchers attempted to model extreme claims and thereby to provide information for better management of business. The objective of this study is to identify the best fit model for tail of the claim distribution based on data obtained from a pioneer insurer in Sri Lanka from July to December of 2021. The Peak Over Threshold approach of the Extreme Value Theory was applied to model the extreme claims. The claims at 20 percentiles between 79% and 98% were considered as tentative thresholds and the excessive amounts over each of these thresholds were modeled separately as Generalized Pareto Distributions (GPDs) using four different parameter estimation methods. Then the Mean Squared Error (MSE) at each threshold for each parameter estimation method was examined to compare their performances. The threshold and the parameter estimation method with the minimum MSE were selected as their optimum values while identifying the GPD fitted as the best model. The Bootstrap goodness of fit measured the validity of modelling. The extent of claims varied from Rs. 2167.00 to 193,065.00 during the study period with a positive skewness of 2.45 and leptokurtic, which confirmed the existence of a heavy tailed distribution for claims. The best fitted model was the GPD with the shape and scale of 1.02 and 92.09 respectively, which was attained at the optimal threshold of 91st percentile using the Biased Probability Weighted Moment method. The information on the tail helps review existing strategies for the better management of risk due to such extreme claims in future.
Open Access
Appropriateness of Commercial Mediation as an Alternative Dispute Resolution Method for Subcontractor Disputes in Sri Lanka
(Sri Lanka Institute of Information Technology, 2023-03-25) Hettiarachchi, D.D; Wijesinghe, T; Perera, B.K.C
Disputes in relation to construction sub-contractors are undeniable and quite diversified in common dispute arena with the legal concerns arising out of Doctrine of Privity of Contracts. Continuation of these disputes can adversely affect the cost, quality, and time metrics in a construction project. The merits of commercial mediation as an alternative dispute resolution method, in this regards Sri Lankan construction industry were less explored. Thus, the aim of this research is to determine the appropriateness of commercial mediation as an alternative dispute resolution method for subcontractor disputes. To achieve this aim, a mixed research approach was adopted. Qualitative data was collected through semi structured expert interviews. Then through a questionnaire survey, quantitative data has been gathered. While qualitative data were analyzed through content analysis, quantitative data were analyzed through relative importance index and descriptive analysis based on central tendency dispersion. Initially, both common attributes of commercial mediation and subcontractor disputes in construction industry were listed out. Then, the inter-relationship between two factors were observed. According to the findings, bespoke and incomplete contracts, subcontractor unawareness and lack of knowledge about contract details, liability and responsibility issues, failure to respond in time, interface issues and lack of coordination were identified as the most significant attributes of subcontractor disputes. Further, it was proven that except the attribute ‘having freedom to accept or reject the solution’, all the other attributes of commercial mediation were applicable in resolving subcontractor disputes. Hence, the commercial mediation was determined as an appropriate alternative dispute resolution method in resolving subcontractor disputes in construction projects. All the limitations and necessary recommendations for further studies are presented at the end of the study.
Open Access
Aspects of Structural Vulnerability against Tsunamis
(SLIIT, Faculty of Engineering, 2022-02-11) Dias, P
Using historical data, it is shown that tsunamis may not occur for earthquake magnitudes even up to Mw = 8. Field data can be used to arrive at generalized fragility curves for different materials of construction as functions of inundation depth. Such curves can also be integrated into vulnerability curves that can be characterized by simple negative exponential equations. It is also possible to create synthetic fragility curves generated by Monte Carlo simulation, which were found to have a reasonable fit with the empirical ones. While most simulations focus only on the structural frames in buildings, partitions can also play a significant role in damage mechanisms. There is also a role for simplified indices of either risk or robustness, based ideally on physics rather than expert opinion. Such indices can also be used to consider risk to an entire system, for example buildings, functions and backup services that are spread across adjacent coastline hospitals.
Open Access
Assessment of Nationally Determined Contributions of Sri Lankan Power Sector
(SLIIT, 2022-02-11) Dahanayake, A; Fernando, G; Liyanage, M
The nationally determined contributions (NDCs) aim to attend long-term temperature goals, which have been imposed by the Paris agreement to strengthen climate change efforts. Fossil fuel is the major energy source in power generation in Sri Lanka, contributing 67% of total input energies. Sri Lanka is intended to achieve 70% renewable energy in the power sector by 2030 and achieve carbon neutrality in the power sector by 2050 through its NDCs. This study analysed the NDCs in the Sri Lankan power sector. The study was carried out through Asia-Pacific Integrated Assessment Model (AIM/End-use), a recursive dynamic least-cost optimisation framework based on bottom-up modelling principles. The Sri Lankan Power sector has been categorised into a few sectors based on the fuels used in power generation. It mainly considers thermal coal, thermal oil, and hydro. It will also consider all the existing power generation technologies, committed technologies and technologies identified as candidates. A business-as-usual scenario (BAU) and three alternatives NDC were considered in this study. These NDCs include enhancing renewable energy by adding 3867 MW, converting existing fuel oil-based combined cycle power plants to natural gas and establishing new natural gas plants, and improving the efficiency of transmission and distribution network (lost reduction 0.5% compared with BAU by 2030). The study analysed the output data and confirmed the feasibility of meeting GHG emission reduction targets through consideration of selected NDCs in the time span of 2020-2030. The GHG emissions from the BAU scenario and three countermeasure scenarios were analysed in 2015-2050. The input primary energy supply was determined to compare the variation in energy with the effect of NDCs
Embargo
Associations Between Socioeconomic and Trip Characteristics of Bus Passengers to Plan for Transfer-Based Bus Transport Operations (TBBTN)
(SLIIT, Faculty of Engineering, 2024-10) Silva, K.N.R.; Sharic, A.H.S.; Bandara, J.M.S.J.
Sri Lanka's bus transportation system relies heavily on direct routes connecting main town or city centers, leading to operational challenges such as route overlap, increased fleet requirements, and financial losses. To address these issues, this study advocates for a transfer-based bus transportation (TBBTN) approach. The proposed strategy involves shortening route lengths, boosting service frequency, and minimizing overlap to potentially enhance revenue per kilometer for operators. However, this approach introduces passenger inconvenience as travelers are required to switch buses. Analyzing the associations between passenger socioeconomic characteristics and trip characteristics is crucial for effective TBBTN planning. Data was collected through interviews with randomly selected passengers, and the study revealed that as passengers' ages increased, their service expectations rose, with younger passengers expressing concerns about trip costs. The TBBTN aims to streamline transfers and reduce travel expenses, catering to diverse income groups. The positive correlation between income levels and service expectations supports the potential for TBBTN to offer improved amenities. With buses being widely used for work and educational trips and considering reduced car ownership among young and middle-aged passengers, TBBTN emerges as an affordable alternative. The study also emphasizes the importance of addressing gender-specific service expectations, particularly safety concerns among females, by establishing well-lit and secure transfer points. Ultimately, the proposal recommends prioritizing passenger expectations, affordability, and addressing diverse demographic needs to enhance the overall transportation experience for all.
Embargo
Auto-encoder Based Data Clustering for Typical and Atypical Repetitive Child Hand Movement Pattern Identification
(SLIIT, Faculty of Engineering, 2024-10) Wedasingha, N; Samarasinhe, P; Seneviratne, L; Papandrea, M; Puiatti, A
This study is dedicated to the important task of identifying unique repetitive hand movement patterns in children, with the aim of facilitating early anomaly detection. The current body of literature lacks a comprehensive model capable of effectively discerning distinctive patterns in child repetitive hand movements. To address this gap, our innovative approach employs autoencoders to efficiently compress intricate data and extract latent features from a dataset with inherent limitations. By utilizing clustering techniques, we analyze these features to reveal distinct behaviors associated with child hand movements. Despite the challenges posed by binary annotated datasets, our model demonstrates outstanding performance in categorizing movements into four distinct types, thereby providing valuable insights into the intricate landscape of child hand movement patterns. Statistical assessments further underscore the superiority of our autoencoder, achieving a mean Bayesian value of 0.112, outperforming state-of-the-art algorithms in this domain. Subsequent in-depth analysis exposes notable inter-cluster patterns, elucidating transitions from typical to atypical behavior in child hand movements. This research constitutes a significant advancement in the field of child hand movement pattern analysis, offering a powerful and sophisticated tool for healthcare professionals and researchers alike. The automation capabilities embedded in our model empower these professionals to address childhood behavioral disorders more effectively and efficiently. In essence, our research not only contributes to the enhancement of early anomaly detection systems but also serves as a valuable resource for professionals engaged in child healthcare and behavioral research, facilitating a deeper understanding of these nuanced patterns.