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
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 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.
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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
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.
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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.
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Battery-Less Sensor Node Design with Solar Panels and LoRa for Wireless Sensor Networks
(SLIIT, Faculty of Engineering, 2024-10) Premachandra, N.G.P.R; Edirisinghe, S
A wireless sensor network (WSN) is a network of sensors that detect physical changes and convert them into analog or digital signals. These sensors communicate with each other to monitor and collect data from a specific area. Applications of WSNs range from environmental monitoring to agriculture, industrial automation, etc. The current WSN nodes are powered by rechargeable batteries and designed for short distances. The problems faced with current WSNs are short-distance communication, battery replacement in large, deployed networks, and rechargeable batteries that take longer time periods to recharge. The term “battery-less” refers to devices that operate without traditional batteries or external power sources. In this design, solar energy is used as a sustainable energy source, and supercapacitors are used to store the solar energy. Supercapacitors have a greater number of charging-discharging cycles than batteries, which can operate in a wide temperature range. They are also more environmentally friendly than typical batteries. LoRa is the technology used for long-range communication, which operates in Industrial, Scientific, and Medical (ISM) radio bands, which is the most cost-effective technology that provides wide coverage with low power consumption. For power management, lowpower approach and sleep mode are used to make the sensor node work efficiently with the stored power in the supercapacitors. The whole system design was optimized, taking scalability, performance, and cost-effectiveness into account.
Open Access
Causes for Death and Injuries in Construction Industry in Sri Lanka
(SLIIT, 2022-02-11) Wijesekara, M; Fernando, P; Gunarathna, N
The construction industry plays a vital role in the socio-economic development in any country. However, it has been recognized as one of the most hazardous industries in many counties around the world because of the nature of activities and tasks performed at construction sites. Similarly, presentday construction industry of Sri Lanka prioritizes and considers safety as a primary, complex issue due to its high impact on the industry. Accordingly, the aim of this study was to identify the causes for deaths and injuries in construction sites in Sri Lanka and identify actions to mitigate those accidents. The data collection was in the form of documentary review, semi-structured interviews, and questionnaire survey. This study found that the nine (9) most prominent types of accidents that have occurred in Sri Lankan construction sites include falling from heights and scaffoldings, falling debris or objects and machinery accidents. During the last 10-year period 2,135 accidents have been recorded in the construction industry, including both fatal and non-fatal accidents, among which 311 were fatal accidents. As per the study findings, during the period of 2010 – 2020, 14 fatal construction accidents were reported out of every 100 construction accidents. Usually, most of the accidents at construction sites are due to lack of safety at site, working without PPE, inadequate training and lack of supervision. Further, the study also recommends strategies to minimize the identified nine (9) most prominent types of accidents and to improve construction site safety. Findings of this research could help towards reducing the fatal and non-fatal construction accidents in Sri Lanka and to develop safe work environment in the local construction industry.
Open Access
Challenging Arbitral Awards in the Construction Industry
(SLIIT, 2022-02-11) Jayasinghe, R; Dahanayake, R; Edirisinghe, V
One of the most common alternative dispute resolution methods used in the Sri Lankan construction industry is arbitration. However, challenging arbitration awards based on legal grounds at the courts has been a current trend by the disagreeing party. If this situation occurs continuously, the purpose of having arbitration as an alternative dispute resolution method can be abandoned. Therefore, the study aims to identify the causes where arbitration is challenged in multi-story building construction projects in Sri Lanka through a case study. The methodological choice was qualitative and used semistructured interviews from six arbitrators and 2 case studies that referred to courts to challenge arbitration awards as research strategies. The study found the poor attitude of parties, lack of technical knowledge, reliability, and capability of the arbitrator to act according to the arbitrary acts imposed by the government as the main causes. Further. The study recommends arbitrators consider the reasons to act well enough and reject the cases if the arbitration is likely to be challenged in courts, train arbitrators to be reliable and on technical knowledge, and improve parties' attitudes by educating on the arbitration procedure and its benefits.
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ChemicalOxygen Demand Reduction of The Spent Wash Condensate by Applying Sugar Cane Bagasse Ash
(SLIIT, Faculty of Engineering, 2024-10) Lankathilake, L.J.M.U.; Wijesekara, E.R.J.M.D.D.P.; Amarasinghe, A.M.P.
Distillery spent wash is a highly acidic waste generated during ethanol production in sugar industries. It makes a challenging industrial wastewater, due to its high organic content and complexity and it needs to treat before being released into the environment. The spent wash can evaporate, creating a thick slurry and vaporized liquid. The slurry can be used for different applications such as a fertilizer production. This vaporized fraction can be condensed, and this research study focuses on applying a sustainable waste management approach to reduce the COD of spent wash condensate by using ash generated from bagasse combustion. Four experiments were included in the study. First, H2O2-treated and untreated fly ash and bottom ash from the bagasse combusted boiler were mixed with the spent wash condensate and filtered out to determine the most suitable ash type for COD reduction. Then, the chosen ash type was used in various ratios and retention times to determine the optimum operation conditions. Finally, the COD reduction capacity of the boiler ash was determined by treating condensate multiple times. The results indicated that the optimum COD reduction spent wash condensate to treated bagasse fly ash ratio is 1: 50 (W/V), and the optimum retention time is 02 hours. Furthermore, the treated bagasse fly ash can be used twice to treat the condensate of distillery spent wash, and if it wants to be reused more, it should retreat with H2O2. The average COD value of raw spent wash was around 130,000 – 160,000 mg/L range, and it has reduced to approximately 70,000 mg/L in the spent wash condensate. After ash treatments the COD of spent wash condensate can be reduced to approximately 30,000 mg/L. This method can reduce the spent wash COD by about 75%; additional treatment is required to reduce it to an environmentally disposable level.
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Comparative Analysis of Characteristics of Dye-Sensitized Solar Cells Utilizing Extracts of Young vs Mature Leaves of Elaeocarpus Serratus as Natural Sensitizers
(SLIIT, Faculty of Engineering, 2024-10) Davisan, S.; Nupearachchi, C.N.; Perera, V. P. S.
This study addresses the pressing global need for sustainable energy sources by exploring dyesensitized solar cells (DSSCs) as a viable alternative. Specifically, the research focuses on extracting natural pigments from Elaeocarpus serratus (Sri Lankan olive) leaves to enhance the efficiency of DSSCs. These leaves undergo color changes as they mature, presenting opportunities to extract different types of pigments at different ages. Extraction involves boiling pieces of leaves in absolute ethanol to obtain the desired pigments. Further characterization via UV-visible spectroscopy revealed the presence of different absorption bands of pigments in the natural dyes’ extracts. The constructed DSSCs employed these natural dyes, coated on TiO2 films deposited on FTO glass plates as the photoanodes. The liquid electrolyte was I2/I3 - and a platinum-sputtered glass plate served as the counter electrode. Photovoltaic characteristics were evaluated using a computerized PK-IV 100 I-V analyzer under 100 W/m2 illumination. Results indicated the superior performance of DSSCs utilizing young leaf extracts, yielding a short circuit current density (JSC) of 3.950 mA/cm2, open circuit voltage (VOC) of 458.8 mV, and a fill factor (ff) of approximately 0.553 with an efficiency (η) of 1.003%. Conversely, DSSCs utilizing. Mature green leaf extracts exhibited lower performance metrics, with JSC of 2.379 mA/cm2, VOC of 477.5 mV, ff around 0.492, and η of 0.559%. Therefore, the efficiency of DSSC fabricated with young leaf is 56% higher than the DSSC made with mature green leaf extract.
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A Comprehensive 5G NR V2X Simulator for Unicast, Multicast, and Broadcast Communication Modes
(SLIIT, Faculty of Engineering, 2024-10) Dissanayaka, D.M.S.D.; Nethmini, K.G.M.; Dharmarathne, R.G.C.D.S.; Priyankara, W.N.B.A.G.
As the field of vehicular communication continues to evolve, the need for reliable and realistic simulation tools becomes increasingly critical. This paper introduces a novel 5G New Radio Vehicle to Everything (NR V2X) simulator, a state-of-the-art tool to emulate unicast, multicast, and broadcast communication modes. The simulator is built upon the well-established ns-3 network simulator and integrates seamlessly with the Simulation of Urban Mobility (SUMO) traffic simulator. This integration allows for the creation and analysis of complex vehicular communication scenarios, enhancing the realism and applicability of the simulations. One of the key features of our simulator is its flexible architecture. This flexibility enables it to accommodate a wide range of scenarios, making it a versatile tool for researchers and practitioners in vehicular communication. In addition to its technical capabilities, the simulator boasts a user-friendly interface. This interface enhances its accessibility, making it an easyto- use tool for researchers of all levels of expertise. We present an in-depth analysis of the performance of different communication modes under various scenarios. Key performance indicators such as average throughput, delay, and packet loss are evaluated, providing valuable insights into the intricacies of nextgeneration vehicular communication systems. Our work contributes significantly to the advancement of 5G NR V2X research. The simulator is a useful resource for exploring and understanding the complexities of vehicular communication systems, paving the way for future advancements in this exciting field. Our work will inspire further research and development in vehicular communication, bringing us one step closer to realizing the full potential of intelligent transportation systems.
Open Access
Computational Approach for Determining the Variation of Coefficient of Secondary Compression in Secondary Settlement Prediction of Soft Soils
(Sri Lanka Institute of Information Technology, 2023-03-25) Thilakarathne, T.M.D.; Vidurapriya, K.V.D.; Thilakasiri, H.S.
Secondary consolidation settlement takes place in soils after the completion of primary consolidation settlement, which is due to the dissipation of pore water pressure under the applied loads. The secondary settlement usually occurs due to the plastic adjustment of the soil particles and most commonly takes place in organic fine grained soils or soft soils. Hence, it is important to accurately estimate the secondary settlement in soft soils as the final stability of infrastructures built on soft soil grounds mainly depends on the amount of secondary settlement that takes place after the end of primary consolidation settlement. The coefficient of secondary compression (C) is a governing parameter in predicting the secondary settlement which is the slope of the consolidation curve for void ratio versus time. Also, various empirical correlations have been found by the past researches to find the value of the coefficient of secondary compression. In most of the instances, the secondary settlement is estimated by considering the coefficient of secondary compression as a constant value. However, the C value shows a variation with time and this could affect the secondary settlement estimation. Hence, it is necessary to investigate how the variation of coefficient of secondary compression affects the estimation of the secondary settlement in soft soils. In this study, the settlement data obtained from the Weligama Bay Marriot Resort and Spa project, Sri Lanka, is compared with the settlement values obtained from a computer generated programme. The progarmme simulates the settlement by considering the variation of the coefficient of secondary compression and by considering a constant coefficient of secondary compression value. The results show that the consideration of varying coefficient of secondary compression (with time) gives more accurate results than considering a constant coefficient of secondary compression in settlement prediction in soft soils.
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Computational Modelling of Drying Process in a Novel Solar Dryer Design with Experimental Validation
(SLIIT, Faculty of Engineering, 2024-10) Gunathilaka, R.A.C.K.; Kumar, R; Chatterjee, S; Bandara, R.M.P.S.
Crops and food products are dried by a variety of conventional methods, including open-air drying, smoking, and oven-drying for preservation purposes. Due to inherent drawbacks in the conventional drying methods, such as higher energy consumption, possible contamination and uncontrollable drying conditions, solar drying is preferred over the said drying methods. A solar dryer utilizes solar energy to dry crops, food products etc. by harnessing the heat energy from the sun to reduce the moisture content of the substances. The study focuses on modelling the drying process in an indirect type novel solar dryer through computational modelling with subsequent experimental validation of the temperature and air velocity profiles. The solar dryer is comprised of a divergent section, a convergent section, an absorber plate, a drying chamber, an outlet and trays. The Computational Fluid Dynamics (CFD) approach has been adopted in modelling the drying process and ANSYS Fluent has been used as the CFD tool. The computational mesh is comprised of 621,106 tetrahedral mesh elements. Pressurevelocity- coupling numerical scheme was used for discretizing the Navier-Stokes and other transport equations. A realizable k-ε model was applied in modelling turbulence. CFD simulations were conducted for three different mass flow rates of air: 0.0872 kg/s, 0.0636 kg/s, and 0.0447 kg/s at a solar insolation of 996 W/m². CFD simulations provided a comprehensive insight into the temperature and velocity profiles within the solar dryer. Furthermore, modelling results are well aligned with the experimental measurements taken on the solar dryer, confirming the reliability and accuracy of the computational model. The findings of this study will contribute as a platform for optimizing the performance of solar dryer designs.
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Computing Awareness and Computational Thinking in Sri Lankan Street Vendor Communities: A Pilot Study
(SLIIT, Faculty of Engineering, 2024-10) Perera, S.A.K.M; Munasinghe, B.
Although street market is a common and diverse form of informal economy in a country, the computing awareness and computational capacity of its contributing communities are largely understudied. This case study attempts to investigate the Computing awareness and Computational Thinking (CT) skills among street vendors in a Sri Lankan urban commercial area, using a mixed methods approach. It summarizes interviews, survey and observational findings about their digital literacy, digital awareness, problem solving skills and algorithmic thinking ability and the results are interpreted to understand their Computing awareness and CT skills. The findings reveal that Sri Lankan urban street vendors use digital devices, especially smartphones, for various purposes related to their vending activities, yet face concerns and challenges in accessing, affording, and trusting digital technologies. They seem to apply algorithmic thinking in planning, organizing, and optimizing their vending operations, and display problem-solving skills in coping with uncertainties, risks, and conflicts in their work environment, reflecting their resilience and adaptability. The study confirms that CT could be a valuable and relevant skill for street vendors and recognizing and nurturing these skills can enhance their socio-economic inclusion and resilience. The study also provides indicators for future research, such as exploring the gender and generational differences in both Computer awareness and Computational Thinking skills and evaluating the impact of educational interventions in those areas.