Browsing by Author "Jayarathna, P"

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item: Conference-Abstract
Adaptation of Kindura mythical creature in traditional arts and crafts of Sri Lanka : an analysis of graphical adaptation and its impact
Bulumulla, V; Jayarathna, P
The word “myth” comes from the Greek “mythos”, meaning a word or a story. Humankind has made myths from the dawn of history. Many common themes run through world of myths and one such theme connects human beings with other animals. Therefore, from the early ages of storytelling, mythical creatures were prominent feature in each human culture. It is noticed that myths of diverse cultures are often linked by similar themes and concepts, but the difference is made with the process of adaptation which were done by each culture according to their own stories, beliefs and ideas. Many researches and studies have been carried to understand the origin and the background stories of these mythical arts, but yet few have been done to understand the graphical adaptations. This study intends to discuss the development of graphical adaptation of the mythical creatures from its original artefacts which is applied in Sri Lankan traditional art and craft. By understanding these graphical and visual adaptation of the local context, this research further places the initial foundation of updating the local mythical legends and creatures in a more effective manner in both art and design aspect, which has not been continued in recent past.
item: Conference-Abstract
Effect of the shape of the solid insulators on creeping discharge propagation under AC voltages
Ediriweera, S; Jayarathna, P; Samarasinghe, R; Lucas, R
This paper studies the use of circular and square shaped solid insulators on creeping discharge propagation over solid/liquid dielectric interfaces under AC voltages. A point-plane electrode arrangement based test apparatus is used to initiate creeping discharges over solid/liquid interfaces and the discharge propagation is captured using a camera. Two shapes of solid material samples are used to analyze the effect of using different shaped dielectric samples for the creeping propagation under AC voltages. Two types of solid materials, glass and acrylic, immersed in copra coconut oil are tested. Discharge length of the discharge patterns and the fractal dimension calculated by box counting method are used to explain the effect of square shaped and circular shaped dielectric samples for the morphology of creeping discharges. Results show that the shape of the solid dielectric material does not have a significant effect on the discharge length, fractal dimension and the shape of the discharge pattern.
item: SRC-Report
A Tool for estimating remaining life of power transformers
(2017) Samarasinghe, R; Lucas, R; Ediriweera, S; Jayarathna, P
Part 1- Modelling the Lumped Parameter Network of a Power Transformer using Sweep Frequency Response Analysis Accurate modeling of power transformers is beneficial for fault diagnosis and the health condition assessment of the power transformers. This project proposed a novel approach of synthesizing the lumped parameter equivalent circuit of a power transformer using its frequency response by utilizing artificial neural networks and the genetic algorithms. A physically realizable transfer function derived using the sweep frequency response data of a power transformer is used to construct its lumped parameter equivalent circuit model. Then, the parameters of the model are estimated using an artificial neural network and the genetic algorithm. All parameters, objectives and constraints of the genetic algorithm and the artificial neural network are set appropriately to ensure accurate results within the shortest time span. The entire approach is validated by means of an error analysis. The proposed method is easy to implement and can be used effectively to improve the reliability of power system though accurate fault identification and health assessment of power transformers. In addition, by replacing general equivalent circuit with the proposed model, the accuracy of transient analysis results can be significantly enhanced as the high frequency behavior is simulated using lumped parameter network. Part 2 - Fractal Characteristics of Creeping Discharges Propagating on Solid/Liquid Dielectric Interfaces A solid/liquid dielectric interface is considered a weak point in a composite insulation system, as it facilitates creeping discharges on the interface. This project proposes the use of nano-dielectrics to minimize the effect of damages which occur due to creeping discharge activity on such interfaces. A point-plane electrode arrangement-based test apparatus, energized by a high voltage supply, is used for analyzing the propagation of creeping discharges over solid/liquid interfaces using visual observation. An algorithm is used to determine the fractal dimension of creeping discharges propagating over various solid/liquid insulating interfaces. The results show that the use of nanofillers can increase the dielectric breakdown strength of epoxy by 7%.