Journal of Advances in Engineering and Technology [JAET] Volume 01 Issue i

Permanent URI for this collectionhttps://rda.sliit.lk/handle/123456789/3042

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Open Access
Application of Sentinel-2 Satellite Data to Map Forest Cover in Southeast Sri Lanka through the Random Forest Classifier
(SLIIT, Faculty of Engineering, 2022-09) Gunawansa, T; Perera, K; Apan, A; Hettiarachchi, N
Sentinel-2 satellite data has been used for forest cover monitoring for almost five years. Mapping with Sentinel data will be a cost-effective solution for Sri Lanka, where the lack of updated land cover maps with high spatial resolution is a significant challenge in the land resource management of the country. A study area of about 5,000 km2 located in southeast Sri Lanka was selected for this study. Agricultural lands, forests including Yala national park, and villages with perennial crops make up the region. A Level-2A Sentinel-2 image with less than 10 percent cloud cover was used in the European Space Agency's (ESA) SNAP software version 8.0.0 for image processing and the forest cover of the study area was mapped through the Random Forest classifier (RFC). Normalized Difference Vegetation Index (NDVI) is also calculated as a Sentinel product to support RFC output. For RFC, ground truth data were collected through the reference of Google Earth high-resolution data. The classification accuracy was assessed using the Google Earth image as the reference dataset. Furthermore, RFC results were compared with NVDI greenness values. The classification accuracy was calculated using a confusion matrix (error matrix) through randomly selected 100 sample points. The overall accuracy of the land cover map was 85 percent, with a 96 percent accuracy for forest cover identification. The study found RFC as an effective method to isolate forest cover in Sri Lanka.
Open Access
Vertical Axis Wind Turbine for Sri Lankan Southern Highway
(SLIIT, Faculty of Engineering, 2022-09-22) Perera, S; Nandasena, D; Wijayakumara, D; Guruvita, K
Based on studies, most of the areas in Sri Lanka have an average amount of wind that could be resourceful in generating wind power. The area from Colombo along the coastal line to Matara is considered to have less wind potential. It’s a major disadvantage to the country’s energy generation plan as wind is one of the best renewable energy sources available in Sri Lanka. Concerning the energy crisis in the country, the necessity for a renewable energy source has arisen. Since renewable resources are used as standalone systems, the level of advancement increases while reducing the amount of stress on the main electrical grid when balancing the frequency. Highways can be followed as one of the country’s leading divisions that could be used for the use of renewable energy. The southern expressway in Sri Lanka requires an average of 375 kW of electricity only for lighting purposes. If the lights are turned on for 12 hours, then the amount of energy requirement is 4,500 KWh. It would save a considerable amount of energy from the national grid if that energy could be provided using renewable sources. This reduction of energy consumption from the main grid would benefit both the authorities of the Sri Lankan power system and the public. To address the aforementioned issue, a vertical axis wind turbine is proposed in this project to be installed on highways. The main requirements of the project are highlighted in the introduction and problem statement. All the details of the outcomes such as optimized rotor, gear system, generator and the PIC-based power management system are explained in detail with the steps taken to optimize the system at every possible step. There are plans which may facilitate the future development of the product included in the latter part of the document.
Open Access
Factors Affecting Red-Light Running of Pedestrians at Signalized Intersections
(SLIIT, Faculty of Engineering, 2022-09-22) Herath, C; Amarasingha, N
Hundreds of pedestrians have died and many have been injured in the past decades as a result of Red Light Running (RLR) infractions. According to the United States Department of Transportation, 846 pedestrians have died and 143,000 have been injured in 2019 due to RLR violations. The majority of previous studies have focused on pedestrian behavior at an intersection, whereas only a few have looked into pedestrian RLR violations. The main objectives of this research are to find the pedestrians’ RLR rate in Sri Lanka and to find ways to reduce the RLR rate of pedestrians at the signalized crossing. Video observation surveys were conducted to collect data at three signalized intersections within Kandy city limits during weekdays for two hours per site. Pedestrian demographic variables such as gender and age; crossing characteristics such as crossing type, direction, crossing speed etc; and site characteristics such as crossing length, pedestrian green time, etc. were recorded. Chi-square and binary logistic regression tests were done. Results showed that out of 178 females, 130 had compliance with signal phases and out of 386 males, only 215 had compliance with RLR of a pedestrian. Furthermore, other independent variables such as age, crossing type, direction etc. were also associated with compliance RLR of pedestrians under Chi-square results. Based on the results of binary logistic regression, the variables such as gender, crossing type, number of traffic lanes, and pedestrian speed are significant when decreasing the log of probability -0.658, -3.040, -1.022 and -2.556 of compliance for RLR respectively. Variables that crosswalk utilization are also significant when increasing the log of probability of RLR 1.406 of compliance for RLR. The results would help develop safer pedestrian infrastructures and engineering countermeasures as well as assist the researchers and practitioners in better understanding pedestrian crossing behavior at signalized intersections.
Open Access
Developing a Rubber based Nanocomposite
(SLIIT, Faculty of Engineering, 2022-09-22) Sadique, M. I. F
Polymer compounds such as Natural Rubber (NR), which consists of compounds such as isoprene, are capable of being processed for the manufacture of a range of rubber based products for a large variety of applications. The properties of a natural rubber compound are susceptible to enhancements in their properties through the incorporation of nanofillers into its matrix. This study addresses the preparation of a natural rubber based nanocomposite that utilizes graphene as a nanofiller for the facilitation of the required enhancement in the rubber compounds properties. The nanocomposite specimens used in the study were prepared by means of acid-coagulation. The acid-coagulation formulation utilized was adapted from methodologies employed in commercial applications. The enhancement in the rubber properties due to the incorporation of the nanofiller was validated by means of mechanical testing. Prior to the testing, the applicable standard for tensile property testing was identified to be ASTM D412. Through the acclaimed standard, a mould to facilitate the preparation of the required specimens was 3D printed from PETG. The primary aim of the study was to determine the effect of large concentrations of graphene (beyond 2.5wt %).The results from the mechanical testing of the acidcoagulated samples exhibited enhancements in the elongation at break and tensile strength between unfilled NR and the graphene filled NR nanocomposite. With the incorporation of 5wt% of graphene, the elongation at break of the rubber increased to 687%, showing a 25% increase. The tensile strength of the rubber increased to 4.07 MPa, showing an enhancement of 102% in comparison to the pristine rubber compound.
Open Access
Attributes of ADR in the Sri Lankan Construction Industry
(SLIIT, Faculty of Engineering, 2022-09-22) Edirisinghe, V; Marsh, D; Borthwick, F; Siriwardena, M; Cotgrave, A
Alternative dispute resolution (ADR) methods were introduced to the construction industry to avoid the negative effects of litigation in relation to the cost, time, and business relationships of a construction project. This study focused on identifying the current ADR practices in the Sri Lankan construction industry and examined the specific attributes of each method to create a more effective process. A qualitative research strategy was carried out with interviews with industry professionals working in the Sri Lankan Construction Industry. Content analysis using NVivo software was used to analyse the data. The key findings revealed that the neutral third party has good knowledge of construction. Despite the differences in each ADR method, disputing parties do not have the confidence in the neutral third party or trust in the process. This study also revealed that the unavailability of these key attributes will finally affect the cost and reputation of the ADR methods. Therefore, the research suggests that to improve the ADR process and its success there should be awareness studies on ADR methods and training for ADR practitioners within the Sri Lankan Construction Industry.
Open Access
Understanding the Characteristics of the Heatwaves using Temperature as the Only Variable – A Case Study on the Heatwaves in 1994 in South Korea
(SLIIT, Faculty of Engineering, 2022-09-22) Chandrasekara, S. S. K; Kwon, H. H
Acutely warm weather coupled with extreme weather variables or latent cooling due to a deficit of soil moisture could generate heatwaves. South Korea is highly susceptible to heatwaves that occur annually in different intensities and cause devastating impacts. This study aimed to identify the characteristics of the heatwaves, especially focusing on one of the most severe heatwaves observed in 1994 in South Korea using only temperature as a variable. The summer season, June to September (JJAS), was selected for the study because heatwaves were prominent during the summer in South Korea. The maximum and minimum daily temperatures were collected from the 67 meteorological stations located in South Korea. The mean daily 95th percentiles of the temperatures were assessed to identify the heatwave durations and the intensities. In 1994, the 15 stations recorded their highest heatwave durations, and durations varied between 48 to 66 days in the JJAS season. Busan station recorded the highest heatwave duration in 1994, which persisted for 66 days or throughout half of the season. Further, it was interesting to identify that coastal meteorological stations were most vulnerable to heatwaves in South Korea. However, the relationship between temperature intensities and heatwave duration for coastal cities showed statistically low significance. Furthermore, it is identified that the daily maximum temperature was most influential in the occurrence of heatwaves in both the coastal and mainland meteorological stations, except for Pohang and Ulleungdo. Therefore, the characteristics of heatwaves observed in 1994 in South Korea were identified using temperature as the only variable. Furthermore, a study on the dynamic atmospheric oscillations due to heated waves in coastal regions of South Korea over characteristics of heatwaves observed in South Korea is suggested
Open Access
Design and Dynamic Modelling of Knee Exoskeleton for Disabled People through ADAMS-Simulink Co-simulation
(SLIIT, Faculty of Engineering, 2022-09-22) Ranaweera, J. P; Perera, M
This paper is written to outline the progress and findings of an undergraduate research project aimed at the designing and modelling of an exoskeleton design of the knee joint for rehabilitation and gait support. It focuses on the rehabilitation potential of the proposed exoskeleton design on patients with Hemiplegia and Monoplegia conditions with the objective of seeking a feasible, simple means of joint actuation to reduce the complexity of the design. Exoskeleton designs are able to provide rehabilitation and improve the overall quality of life of disabled people globally. However, a common issue found almost everywhere is the costly nature of the exoskeletons that are available in the market now as they are exclusive devices, which makes them inaccessible and impractical to the general public, especially in developing countries. Initially, the paper focuses on the review of relevant literature and previous research and evaluating the designs that have been developed as of now. A thorough analysis of the work done by previous researchers and companies was conducted to gather data on the underlying engineering principles and techniques used for the exoskeleton development as well as any limitations or restrictions to the process. Conceptual designing of the possible solutions was developed using the understanding and knowledge gathered during the literature review. The selection of the best solution was based on the analysis of the pros and cons of all the solutions. The chosen design, utilising a 4-bar mechanism, was then modelled using SolidWorks software to provide a clear visualisation of the system. The kinematic and dynamic analysis of the mechanism was evaluated to analyse the possibility of using the proposed exoskeleton design by replicating the model in ADAMS multibody software. The dynamic analysis was conducted by using the co-simulation platform between ADAMS and Simulink to enable the addition and control of feedback loops within the system. The results of the analysis show that the design can achieve the required motions of the human gait cycle, especially during the swing phase of the gait cycle. The analysis of the actuation torques and reaction forces on the human body showed that an acceptable torque range was possible during the swing phase of the gait cycle.