SLIIT International Conference On Engineering and Technology Vol. 01 [SICET] 2022

Permanent URI for this collectionhttps://rda.sliit.lk/handle/123456789/2988

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Open Access
Support Vector Machine Based an Efficient and Accurate Seasonal Weather Forecasting Approach with Minimal Data Quantities
(SLIIT, 2022-02-11) Chandrasekara, S; Tennekoon, S; Abhayasinghe, N; Seneviratne, L
Climate change makes a big impact in our daily activities. Therefore, forecasting climate changes prior to its actual occurrences is important. Even though highly accurate weather prediction systems throughout the world are available, they require mass amounts of data exceeding thousands of data points to obtain a significant accuracy. This study was aimed at proposing a Support Vector Machine based approach to carryout seasonal weather predictions up to thirty-minute intervals, the results of which would be considerably effective with respect to predictions carried out with models trained with annual datasets. The model was trained utilizing a dataset corresponding to the district of Kandy which consisted of 136 samples, 20 features, and 5 labels. By means of carrying out numerous data preprocessing steps, the model was trained, and the relevant hyperparameters were optimized considering the grid search algorithm to yield a maximum accuracy of 86%, once tested via the k-fold cross validation. The performance of the Support Vector Machine was also then compared for the same dataset with that of the K-Nearest Neighbor algorithm which consumed relatively fewer computing resources. An optimal accuracy of 61% was observed for this model for a K-value of 27. This approach supported the concept of a Support Vector Machine’s ability to perceive time series forecasts to a relatively higher degree and its ability to perform effectively in higher dimensional datasets with smaller number of samples. As per the future work, the Receiver Operating Characteristic analysis is proposed to be carried out to evaluate the performance of the model and the dataset size is proposed to be further enhanced to a maximum of a thousand samples to yield the best performance results.
Open Access
Relationship between procurement systems and payment methods in assuring financial safety in Sri Lankan building projects
(SLIIT, 2022-02-11) Niriella, A; Gamage, I
The Construction industry is a place where the parties to a project frequently face various risks throughout the project life cycle. Financial risks are one of the aforementioned risks that have a significant impact on parties, and more studies should be conducted to investigate the possibility of minimizing these financial risks and assuring the financial safety of projects. Thus, this research aims at identifying the relationship between procurement systems and payment methods towards assuring the financial safety of construction projects. Researchers selected government funded building projects to limit the scope because such projects frequently deal with financial risks. Frequent financial risks in a Government Funded Building Projects (GFBP) were identified as material shortages, fluctuation of inflation rate, legislation changes. The study used a mixed method approach, and data was gathered through semi structured interviews and questionnaires. Data was analyzed using manual content analysis and basic statistics. Common procurement systems and payment methods available in a GFBP were identified through interviews. Accordingly traditional, design and build, management oriented and collaborative procurement systems were identified and lumpsum, measure and pay, Guaranteed Maximum Price (GMP) and cost reimbursement were identified as payment methods. Furthermore, findings revealed that there are six common combinations between procurement systems and payment methods in GFBP. The identified combinations were further tested for their ability to minimize financial risks of GFBP and it was revealed that the combination consisting of Lumpsum with Design and Build was the best combination to assure financial safety in GFBP. Other combinations are traditional with measure and pay, design and build with lumpsum, design and build with GMP, management oriented with lumpsum, management oriented with measure and pay. Ultimately, a framework has been developed by harmonizing all the research findings in which parties can select the most viable combination to assure the financial safety of their project.
Open Access
Review on Use of End-Area-Rule for Volume Calculations in Highway Pavements
(SLIIT, 2022-02-11) Wanasinghe, G. I; Thennakoon, P. G; de Silva, N. A; Kalugamuwa, I. M
Volume estimation of highway pavements is very important in planning and design of highways, in order to calculate the amount of materials and hence for cost analysis. It is also used to investigate the workmanship and quality of construction in post analysis. End area rule is the simplest and most widely used technique in volume calculation as it can be used with the cross sections generated at a suitable interval. The theory being used for road segment between two consecutive cross sections assuming there exists a linear variation of cross sectional areas within the interval. Validity of the application of end area rule depends on this assumption and accuracy also varies when the linear variation does not exist. This study was carried out to analyze the validity of the application of end area rule due to the non-linearity of variation of cross sectional areas in highway pavements. The scope of the study was limited to straight segment with rectangular cross section. Road width and height of the cross section were selected as variables and the volumes were compared using different models with coaxial centroids and skew sections. Numerical models with different angles of centroids were used in the study and the results were verified using digital models created with AutoCAD 3D software. The interval between sections was also investigated and it was determined that the perpendicular distance between sections should be used in the end area rule. Finally it was concluded that the area variation is not linear when there are more than one variable affect the cross section. The modification to end area rule was also developed in order to increase the accuracy.
Open Access
Spatial Patterns and Temporal Trends of Rainfall Seasonality in Sri Lanka
(SLIIT, 2022-02-11) Amarasinghe, H.G.K.H.; Basnayake, B.M.L.A.
Understanding and knowledge of rainfall variability is necessitated for agricultural planning, flood mitigation activities, and water resources planning and management. Like other rainfall characteristics seasonality of rainfall is also spatio-temporally specific which has not been evaluated to Sri Lanka. In this study, seasonality in rainfall over Sri Lanka was analyzed using the seasonality index (SI) proposed by Walsh and Lawler. Rainfall data at 39 raingauge stations for the period 1988-2017 were collected to obtain the annual monthly rainfall cycles. The SI, a measure of annual rainfall distribution, was used to identify different rainfall regimes. Southwest and central highlands covering the stations Baddegama, Pelawatte, Kudawa, Deniyaya, Mawarella, Mapalana and Beausejour (lower) were identified as “equable with a definite wetter season”. Skirting to the definite wetter season was the “rather seasonal with a short drier season” regime surrounding the Colombo, Ratmalana, Nuwara Eliya, and Bandarawela. The region centered on Mannar received the most rain in three months or less. Markedly seasonal with a long drier season is in the eastern extending from Pottuvil to Trincomalee and in the northern part of the country above Puttalam and Maha Illuppallama except the surrounding of Mannar. Intermediate region to SI classes “rather seasonal with a short drier season” and “markedly seasonal with a long drier season” was designated as “seasonal”. However, the seasonal rainfall contribution, i.e., in NEM (Dec.-Feb.), IM1 (March-April), SWM (May-Sep.), and IM2 (Oct.-Nov.), and the annual monthly rainfall profiles confirmed the presence of sub-regimes within the identified rainfall regimes. Non-parametric Mann-Kendall test and Sen’s slope were applied to identify the temporal changes in SI. Approximately, half of the country showed strong trends in the SI. Sixty one percent of the area including the northern part of the country surrounding Jaffna and the definite wetter region in the southern corresponds to the decreasing trend in seasonality.
Open Access
INVESTIGATION MECHANICAL & DURABILITY PROPERTIES OF CRUMBED RUBBER CONCRETE CONTAINING RECYCLED CONCRETE AGGREGATE
(SLIIT, 2022-02-11) Herath, H.M.V.K; Mendis, A. S. M
The concrete construction industry requires huge amount of natural resources. Currently natural resources are depleting while demand for concrete is increasing. Several studies are focused to solve this issue. The waste rubber has become a huge environmental issue worldwide. Researchers identified a sustainable way of reusing waste rubber by recycling it to Crumbed Rubber and partially replacing that for fine aggregate in concrete. However, with introduction of this crumbed rubber to concrete, the compressive strength of developed concrete was decreased. Therefore, the main aim of this research is to improve compressive strength in Crumbed Rubber Concrete using recycle concrete aggregate. Other than that, some fresh properties, mechanical & durability properties were investigated. 15 percent of replacement of fine aggregate by rubber has been identified as an optimum replacement level by other studies. Therefore, this study was conducted for 15% volume based fine aggregate replacement. As recycle aggregate act as a cementitious binder, it was added in 10,15,20,30 percent of weight basis for cement. The w/c ratio was kept constant at 0.57. Maximum 10 mm aggregate was used in the study. The crumbed rubber replacement resulted in 60 percent decrement in compressive strength and recycled aggregate in all levels resulted in a higher compressive strength than rubber-only concrete but got optimum increment in 20 percent and starts to decrease. Same as compressive strength, splitting tensile, flexural strength increased to optimum values with 20 percent of recycled aggregate. The available design codes were used to calculate theoretical values using experimental values to investigate adequacy of these mixes. The investigate revealed that available standard guidelines cannot be used to predict the behavior of crumbed rubber concrete containing recycled concrete aggregate. This study proves that addition of recycle aggregate to crumbed rubber concrete improves its strength. However, the durability and dynamic properties of this developed concrete needs to be investigated.
Open Access
Conflicts Handling Styles Used by Professionals at Pre-Contract Stage of Building Construction Projects in Sri Lanka
(SLIIT, 2022-02-11) De Silva, p; Sandanayake, Y. G
Conflicts between design team professionals is a common experience in building construction projects in Sri Lanka. Depending on the way they are been handled, these conflicts bring either positive or negative impacts to the project. Thus, this paper investigates the conflict-handling styles that the professionals use to handle different types of conflicts among themselves at pre-contract stage of construction projects in Sri Lanka. The study on different types of conflicts and handling styles were derived through quantitative approach by a questionnaire survey designed incorporating Rahim’s Organisational Conflict InventoryII (ROCI-II) with the participation of 42 number of professionals engaged during the pre-contract stage of building construction projects in Sri Lanka. The scope of the study was limited to the building construction projects and only to the conflicts among professionals at the same level. The collected data were analysed using descriptive statistics. The research findings revealed that there are four types of conflicts: task, relationship, process and status conflicts, occur in different frequencies among the professionals. The task conflicts occur very often, and process conflicts occur often whilst relationship and status conflicts occur rarely among professionals during the pre-contract stage. This study revealed that professionals use different conflict handling styles to handle these four types of conflicts among themselves during the pre-contract stage of building construction projects in Sri Lanka. Further, majority of professionals use integrating style often to handle conflicts among themselves, and they use avoiding style very rarely to handle the conflicts among themselves except for relationship conflicts. However, to handle relationship conflicts, professionals use dominating style as the last option. The study would assist the industry practitioners to identify their personnel conflict handling style and the outcome of using each style with their supervisors when handling conflicts during the precontract stage.
Open Access
Performance Prediction Models for Flexible Pavements in Sri Lanka
(SLIIT, 2022-02-11) Amarasingha, N; Opanayake, P
The pavement prediction model forecasts the future PCI ratings based on pavement category, thickness, traffic, pavement life period and existing PCI rating. Nevertheless, with time and inclusion of newer pavement types, there was a need to adjust the prevailing pavement performance models. In addition to, pavements management systems need to develop new models for newer pavement types as well. Some developed pavement performance models in the earlier for the Road Development Authority (RDA) Sri Lanka is used by the roadway segments to predict the future condition and rehabilitations of its network. The available data collections in the roadway agencies in Sri Lanka was used for the research study and the methodology and the analysis section depended on that data collection. Probably we were given the IRI data collections which were done in southern expressway section in Sri Lanka. Based on that data, the analysis part was done for determine the pavement roughness deterioration curves. With a comparison of the developed models, the most suitable model was taken at 95% confidence level with 0.8009 R2 value. This study displays outcomes about of standardizing the present performance models, and creating unused models for the different asphalt forms within the roadway network in Sri Lanka. A comparison of IRI progression with pavement age and traffic volume is also conducted to see if there are major differences between such models developed in other countries. The anticipated expectations condition of the asphalts is utilized in assessing its outstanding benefit life to disappointment, which is of prompt utilize in prescribing future upkeep and recovery necessities for the arrange.
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
Preparation of a Low Cost Nutrient Bar Incorporated with Underutilized Seeds as a Convenient and Functional Meal Replacement Alternative D
(SLIIT, 2022-02-11) Bandigamapalage, W; Chandrasiri, T; Wijesekara, K
People with busy lifestyles routinely consume fast food as an easy alternative for main meal. Consequently, they prone to suffer from non-communicable diseases such as diabetics. The purpose of this research was to develop a nutritious bar as a meal replacement under the Recommended Dietary Allowances (RDA) using underutilized seeds such as pumpkin, winged beans, watermelon, corn, mung beans, and rice flakes. The proximate analysis, physicochemical properties, sensory attributes and microbiological parameters were evaluated using the Association of Official Agricultural Chemist standards (AOAC), Human Research Ethics Committee standards (Brazil), and Sri Lanka Standards Institution (SLS 516: 1991) respectively. Developed mung based (321), rice flake based (123) and commercial nutrient bar (801) revealed a significant difference (p ≤ 0.05) in attributes except mouthfeel in the sensory evaluation. A mold and a package was designed with an effective packaging material. The shelf-life was evaluated after adding the permitted preservative (E211-Sodium benzoate) to developed mung based (321), rice flake based (123) bars which had a self-life of one-month. The mung based nutrient bar revealed an average of 1.7±0.1 % moisture, 0.9±0.7% fat, 9.7±0.1% ash, 21.8±2.5% crude fibre, 36.6±0.0 % protein, 29.2±8.3% carbohydrates, and the rice flake bar contained an average of 2.2±0.3% moisture, 2.7±0.2% fat, 7.9±0.2 % ash, 11.4±1.4 % crude fibre, 31.9±0.0 % protein, 43.8±0.0 carbohydrates. The commercial nutrient bar had 1.5±0.1% moisture, 1.5±0.0% fat, 7.8±0.0% ash, 0.5±0.5% crude fibre, 32.5±0.0 % protein, and 56.3±3.9% carbohydrates on average. The energy content (kcal) in rice flakes based, mung based and commercial bars were 327.1, 271.3, and 360 respectively. The finding ascertained that the developed nutrient bars (123, 321) directly fulfill the recommended dietary allowance as a meal replacement concerning European Union Commission Regulations and substantiate that the same nutrient profiles in the commercial nutrition bars could be obtained from the developed samples with a lesser processing cost.
Open Access
Critical Supply Chain Problems In Contractor - Subcontractor Interface Of Sri Lankan Building Construction Projects
(SLIIT, 2022-02-11) De Silva, P; Panagodage, T. L
As a developing country, construction industry provides considerable contribution to the Socioeconomic growth of Sri Lanka. However, successful completion of a construction project is yet a challenging task. It requires coordination, collaboration and management of different stakeholders with different objectives. While achieving the objectives of a construction project, a proper management of supply chain is vital as improper management of the supply chain impacts negatively on the construction project delivery process. Prior studies have identified several interfaces which impact on the successful project delivery. The mechanism related to contractor-subcontractor interface highly impacts the ultimate project outcome as it is directly linked with the delivery of the project. This study set out to identify the critical supply chain problems in contractor-subcontractor interface in Sri Lankan building construction projects. The study was derived through a mix method approach. Semi structured interviews were carried out among the industry expertise to identify the supply chain related problems. Thereafter, to identify the critical problems of supply chain, a questionnaire survey was carried out among the industry practitioners in the building construction projects. The data was analyzed using Relative Important Index in order to rank and identify the severity of each identified problem in the contractor – subcontractor interface. The study indicates that, using verbal information, lack of reference to the main contract and nonresponsible responses as the critical problems in the Information flow. In terms of the Material flow: deliveries are not according to the plan, poor labour management and noncompliance with material and components are ranked as the critical problems. Delay in payments, back-to-back payments and payment interest charging as the critical problems under the Capital flow. These findings may assist the industry practitioners to identify the criticality and monitor supply chain problems in contractor- subcontractor interface and to minimize them in building construction projects.
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
REGIONAL RELEVANCY OF THE CIDA PRICE INDICES UNDER THE RESTRICTIONS URGED BY THE COVID-19 PANDEMIC
(SLIIT, 2022-02-11) Nissanka, H. D. N. M; Wijesinghe, T
CIDA price fluctuation formula and price indices provide considerable relief to the estimators in mitigating the risk due to the fluctuation of the price of construction inputs during project execution. But there is a huge outcry that the CIDA indices does not appropriately reflect the actual fluctuation of market prices especially during the period of pandemic. The aim of this research was to identify the appropriateness of CIDA indices in ascertaining the price fluctuation of construction material prices across the regions especially under the restrictions imposed by the Covid-19 pandemic. The study was limited to analysis the regional behavior of material prices based on the significant materials. Market price of construction materials was collected from suppliers, constructors, and construction professionals who are currently involved in construction projects. The market prices were collected from nine provinces of the country for eight different types of significant materials during the period of pandemic. Collected data were first observed for its behavior within and across the provinces to check the appropriateness to be represented by country wide common indices. This was done through the analysis of variance and through the checking of null hypothesis i.e., “always there is no difference in means between the provincial prices of a given material”. Thereafter the fluctuation of provincial prices of given inputs were compared to the variation of respective CIDA indices with the corresponding time to check the parallelism and correlation. In this research, it has been concluded that, there is a requirement for establishing regional monthly indices for construction inputs.
Open Access
Satellite Rainfall Products for analysis of Rainfall trends for Mahaweli River Basin
(SLIIT, 2022-02-11) Perera, H; Gunathilake, M. B; Rathnayakea, U
The presence of accurate and spatiotemporal data is of utmost importance in hydrological studies for river basins. However, limited ground-measured rainfall data restrict the accuracy of these analyses. Data scarcities can often be seen not only in many developing countries but also in the developed world. Therefore, much attention is given to alternative techniques to accomplish the data requirement. Precipitation data extraction from satellite precipitation products is one of the frequently used techniques in the absence of ground-measured rainfall data. The Mahaweli River Basin (MRB) is the largest river basin in Sri Lanka and it covers 1/6th of the total land area of the country. Mahaweli River is the heart of the country and the water of it is being used for many activities, including hydropower development, water supply, irrigation, etc. Therefore, analyzing rainfall trends of MRB is interesting and worthwhile for many stakeholders of the river basin. Therefore, this research investigates the suitability of Satellite Rainfall Products (SRP’s) as an alternative for Rain Gauge measured data in the MRB by performing trend analysis between the two datasets. Six precipitation products, namely PERSIANN, PERSIANNCCS, PERSIANN-CDR, GPM IMERG V06, TRMM-3B42 V7, TRMM-3B42RT V7 were extracted for 10-35 years for 14 locations of the MRB spatially distributed in the three climatic zones of the catchment. Non-parametric tests, including the Mann-Kendall test and Sen’s slope estimator tests, were used to detect the possible rainfall trends in precipitation products. Significant increasing trends were observed for both ground-measured and SRP’s in the annual scale while mixed results were observed in monthly and seasonal scales. The trends from ground-measured rainfall and SRP’s were compared and the suitability of SRP’s as an alternative technique was stated.
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.
Open Access
A Study on Curbside Overtaking in Sri Lankan Streets
(SLIIT, 2022-02-11) Amarasingha, N; Eranga, A. L. C
Overtaking slower moving vehicles on the curbside under mix traffic condition is very common in Sri Lanka. The overtaking should never be done from the curbside as a rule of thumb, also rules and regulations regarding the overtaking should be never broken by drivers. Traffic accidents statistics reveal that main cause for serious accidents in Sri Lanka are excessive speed and incorrect overtaking. However, to the best of authors’ knowledge any research about curbside overtaking behavior has not been done so far. Objectives of this study are to investigate self-reported drivers’ overtaking behavior, and to find out drivers’ perspective about current rules and regulations on overtaking. A questionnaire form was developed, and a survey was conducted to collect data among 430 people in Colombo district. Chi–square tests and multinomial logistic regression analysis were done. Chi – square test results showed that among the selected variables, gender, age, occupation, driving license availability, charged a fine or accident due to curbside overtaking are the main factors that affect the curbside overtaking. The results of this study are facilitative to understand characteristics and some reasons behind curbside overtaking. Some methods such as educate public about dangerous overtaking and rules by organizing awareness programs, increasing fine for curbside overtaking, and imposing new laws are suggested to minimize the number of road accidents caused by overtaking slow moving vehicles on the curbside of the road.
Open Access
REGULARITIES AND PATTERNS OF CONSTRUCTION COSTS UPON POLITICAL EVENTS
(SLIIT, 2022-02-11) Perera, B. K. C; Jayasena, H. S
Though the market prices change before and after political events were often speculated, if such changes could be systematically accounted for in construction cost forecasting was unknown. This study aimed to bridge this knowledge gap by identifying the regularities and patterns of the construction costs upon political events. A decade of period was selected in which the scope of the study started in 2010. Time series analysis was used along with regression analysis, assuming a linear relationship between construction costs and time. After a comprehensive literature review, CIDA construction cost indices were chosen as the most appropriate cost representation for the local context, and these were taken as the dependent variables. All indices were plotted in diagrams and long-term trends were observed, then indices were carried for further analysis of cycles. Major political events were collected through a document survey and the findings were plotted on the time series analysis output. It was noticed that in 2013 indices were changed mostly, where three provincial elections were held, and some more pattern changes had occurred close to the local government elections which took place in 2011 and 2018. The study concluded that there is neither pattern nor regularity in construction costs upon political events where it cannot be systematically incorporated into construction cost forecasting. However, the findings did not deny the impact of political events on construction costs, and novel areas were found where further explorations are required.
Open Access
Estimation of Person-Kilometers of Travel in Sri Lanka
(SLIIT, 2022-02-11) Gunathilaka, S; Amarasingha, N; Lakmali, M; Perera, C
Person Kilometers of Travel (PKT) provides all trip information of an individual including trips by motorized, non-motorized, public or informal public transport modes. Estimating PKT in developing countries seems much important as PKT is one of key parameters in transport planning and policy making. Since PKT focuses on an individual, it is influenced by socio demography of the person. However, timely PKT is not estimated by relevant agencies of Sri Lanka. The study focused on estimating PKT in Sri Lanka with travel mode distributions. A paper-based travel survey was conducted over all administrative districts in Sri Lanka for collecting trip information and socio demographic factors of people. 9,012 people participated in surveys resulting a 77.62% response rate. Respondents were asked to provide information of their trips in a typical week, in special holidays and seasons, information on travel modes and their socio demographic information. Data obtained from surveys were aggregated to annual level and weighted in order to obtain PKT/person/year under each socio demographic category. Weightages were estimated using census data in each administrative district. The study came up with important findings; weighted PKT estimations and travel mode distributions in each administrative district. Further, statistical comparisons of PKT estimates among different socio demographic groups and districts were conducted using One-Way Analysis of Variance (ANOVA) test. These findings were key contributions to the existing literature in the country.
Open Access
Cryptocurrency Price Prediction: A Comparative Study using LSTM, GRU and Stacking Ensemble Algorithm for Time Series Forecasting
(SLIIT, 2022-02-11) Ashikul Islam, M. D
Technology has significantly reshaped how humans interact with their tangible and intangible surroundings. Cryptocurrency is considered to be one of the most recent technological inventions which revolutionized how we perceive currencies and their functionality. It has become popular because of its safety, security and anonymity. However, volatility remains one of the major issues with cryptocurrencies to this day. Therefore, the primary aim of this paper is to develop LSTM (Long ShortTerm Memory), GRU (Gated Recurrent Units) and a Stacking Ensemble Learning algorithm that efficiently predicts the price of a cryptocurrency for a given period of time. The predictions are then observed and analysed to determine the comparative performance of the said algorithms.
Open Access
Design and Fabrication of a Novel Hybrid Solar Dryer
(SLIIT, 2022-02-11) Perera, C; Fernando, G; Liyanage, M
A hybrid solar dryer was designed and tested for commercial dissemination of active and passive drying methods over traditional sun drying methods. The proposed dryer employs novel features such as user controllability of the drying parameters and includes sensors and controllers for active monitoring of drying parameters. The functionality of the dryer is broadened by using logic control whereby intermittent drying patterns are introduced to the system for more efficient operation. This paper documents the design calculations and fabrication process of the dryer as well as the results of drying obtained under a controlled environment. 10 experiments have been carried out to assess the limits and potential improvements to the system which yielded satisfactory conditions with a temperature fluctuation of ±1℃ and change in %RH of ±2% at any given temperature within the specified limits. The developed system has been used for drying apples which yielded dried products from an initial weight of 346 grams to a final weight of 55 grams in 5 hours in pure convection and the same initial weight was reduced to 52 grams in 3 hours when operating in solar hybrid mode. The average energy consumption of the dryer was obtained at 300 Watts at uninterrupted solar insolation operation and 224 Watts during pure convective operation, portraying the efficient operation of the system to be eligible to be powered by a solar-powered energy storage
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