Browsing by Author "Liyanage, M"

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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
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
Embargo
Development of an Eccentric Legged Quadruped Robot for a Predefined Uneven Terrain
(IEEE, 2022-06-01) Dayawansa, B; Vasudevan, P; Irfan, I; Liyanage, M
Bio-inspired robotics is a relatively new branch in the field of robotics. It involves the study of the anatomical, morphological and physical behavior of natural living animals and implementing such morphologies and mechanisms in an electro-mechanical system. The field of bio-inspired robotics has given birth to many complex mobile robot topologies which also include legged locomotion. Legged robots help the designers gain an insight into how the biomechanics of animals operate which also can help inspire new technologies in the field of prosthetics and artificial limbs. Legged robots have a higher terrain adaptability and mobility compared to wheeled robots which makes them a good choice for uneven terrain navigation. Legged locomotion itself has a wide scope with various topologies and morphologies involved. In this paper we have evaluated all existing quadruped robot models currently, and have proposed a distinctive quadruped model structure and morphology for uneven terrain locomotion. The robot model has been analyzed through computational modelling and simulation techniques for optimum leg morphologies and gait patterns. The results demonstrated that certain leg morphologies were more efficient compared to other considered leg morphologies. The robot was fabricated physically and tested for the same morphologies in an uneven terrain as well.
Open Access
Enhancement of Images Under Low Light Conditions Using Artificial Intelligence
(Sri Lanka Institute of Information Technology, 2023-03-25) Marzook, M; Herath, M; Liyanage, M; Thilakanayake, T
Images taken in low light conditions do not contain all the information well-lit images contain. Various features including the colours of objects, details and the quality are lost. Extracting these features from images is very important for any kind of application of it. This study proposes a model to enhance the features of the image taken under low light conditions, by delivering a solution which improves the quality of the image through Artificial Intelligence. Through the proposed method, the clarity of the image is improved, making it closer to a well-lit image equivalent. Both Image Processing and Deep Learning based techniques are explored, including Convolutional Neural Network (CNN) based generative models. The Generative models considered are Autoencoders (AE) and Generative Adversarial Networks (GANs). The study has been carried out by using several datasets combined together, which include image pairs of well-lit and low light images. A comparison between the two CNN-based generative models is carried out. Through the study, it is quantitatively found, by the Structural Similarity Index and supported by the Peak Signal to Noise Ratio, that the proposed CNNbased Autoencoder model overrides the proposed CNN-based GAN model. This is further supported by qualitative observations of the image results. Both models, however, greatly enhance the low light images, bringing to light features that were not visible beforehand, and also provide results with good colour accuracy. Through this research study, the methods and solutions to enhance low light images have been addressed, as well as providing a comparison between two suitable models, Autoencoders and GANs. The proposed solution is able to address many of the limitations existing in the extent literature.
Open Access
Simulating the Effects of Active Aerodynamics on the Suspension System of a Formula Student Race Car
(Sri Lanka Institute of Information Technology, 2023-03-25) Epakande, C; Dayawansa, B; Liyanage, M
Active aerodynamics is a growing topic in the automotive industry. With technological advancements at play, it has begun to spread across multiple avenues such as road vehicle ride comfort and the development of active suspension systems. However, the application of active aerodynamics in Formula cars has not been a commonly discussed topic. Furthermore, the effects of active aerodynamics on the suspension system have not been assessed for Formula Student race cars. Therefore, this study looks to obtain an understanding about how actively changing the Angles of Attack of an aerodynamic front wing and a rear wing would affect the suspension system of a Formula Student race car. The study was done by first choosing a wing profile using the XFLR5 software, modelling the front and rear wings using SolidWorks, according to the parametric guidelines of the Formula Student Competition for different angles of attack, analysing coefficients of lift and drag of the wings for each angle of attack using Ansys Workbench, and by performing full-vehicle acceleration and cornering analyses on MSC Adams Car to find how changing these coefficients affects the suspension dampers along the direction normal to the ground the vehicle travels on. This research would help understand the many forces acting on the suspension and to explore further developments in this area such as active aerodynamics in Formula Student race cars in the future.
Open Access
A Study on Local Air Pollution Due to Transport Emissions in Kandy City
(SLIIT, 2022-02-11) Yatigammana, S; Fernando, G; Liyanage, M
Air pollution has become one of the greatest challenges that the world is facing today. According to World Health Organization (WHO)there are 4.2 million annual deaths due to outdoor air pollution. Furthermore, about 90% of global population breathe polluted air. The most harmful cause of outdoor air pollution is recognized to be unorganized traffic management. In the instance of Sri Lanka, Kandy city has been recognized as crucial where necessary actions are required to be taken. This study presents harmful emission values produced by a daily count of vehicles entering the city alongside respiratory diseases and illnesses recorded. Detailed analysis provides pollutant emissions due to unorganized traffic management within Kandy city concentrating over locations from Getambe Junction to Kandy Clock tower and from the city centre towards Mahaiyawa Tunnel and Ampitiya Junction (locations are pinned on figure 1). Calculation of pollutant factors are intended to be done using three main methods namely, Tier 1, Tier 2 and V/C ratio method aided by vehicle fuel type, fuel efficiency, travelled distance and carriageway congestion values. Emission values for pollutants Carbon monoxide (CO), Nitrogen oxides (N2O, NOX) and Sulphur dioxide (SO2) were identified in this study along with PM2.5 and PM10 values. It was to be seen that, over 100,000 vehicle cross Kandy city limits on both weekdays and surprisingly higher values in weekend with each carriageway within the city resulting over a 65% of congestion value. With 31% of daily trips being travel to work, the public transport system fails to deliver its purpose efficiently and effectively. With unorganized traffic management, stagnant and slowmoving vehicles tend to pollute 41% more SO2 and 14% more NOX gasses above global standards affecting the first five kilometers from the city center, which claimed to facilitate the zone of highest quality of life. Current records show PM2.5 values in Kandy to read above 50μg/m3 and PM10 values to be as high as 100μg/m3.