Browsing by Author "Wijesinghe, TM"

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    item: SRC-Report
    Design and construction of a stirling engine
    Dharmawardane, UP; Sudeera, UPMADA; Wickramaratne, C; Wijesinghe, TM; Tissera, PDM
    Prof. R.A. Attalage and Dr.W.M.S.R.Weerasinghe of University of Moratuwa organized our group under the module ME420, with the goal of designing and modeling a Stirling engine that could be used to generate power for small scale applications. In order to develop a compact and low cost Stirling engine, a gamma type Stirling engine with simple regenerator and a rhombic mechanism was developed. Its target shaft power is 50 W at engine speed of 2000 rpm and mean pressure of 0.8 MPa using air as working gas. This report describes the outline of the engine design and the performance test. The test was done without load, using air in atmospheric condition. The results indicate that a higher performance heat exchanger and decreasing of mechanical loss are needed for the attainment of the target performance
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    item: Thesis-Abstract
    Developing broadband models for communities
    Wijesinghe, TM; Samarasinghe, K
    Today, broadband access is regarded as an essential factor for economic and competitive survival in the 21st century. The development of the importance of broadband technology can be likened to the ever-increasing importance ofroad or rail when they were developed. Most advanced economies went through a transition in the second half ofthe 20th century, of being production-driven to service-driven. Now, in the 21st century, these economies are rapidly transforming into more towards being infonnation oriented and knowledge-driven economies. In such an environment, the skill, speed, and innovation needed to transform raw data into valuable knowledge and in turn, to use that knowledge with a profit motive is pivotal to international competitiveness [1]. By bringing the digital world literally to our doorstep, broadband would offer a tantalizing spectrum of benefits, such as, increased business productivity, improved healthcare, better education, interactive entertainment, and most importantly greater governmental efficiency. It is a known fact that Sri Lanka has the most de-regulated telecom sector in the South Asian region [2]. However, the expected economic growth has not been achieved. Possible reasons for this could be the lack of an adequate backbone infrastructure, lack of willingness to share resources, wire line connectivity to the international Internet has not been de-monopolized and the other incumbent operators do not have sufficient resources to invest in under-served areas. As a result of these problems there exists a high digital divide in various parts ofthe country. Therefore, it was considered worthwhile to investigate the potential causes and the long-term solutions for the above issues. The need of a research study was felt as highly necessary by the researcher. The study identifies the most potential candidates for the adoption of broadband. The provinces are considered as communities when identifying the most potential broadband candidates. The research study finally reveals that the Western Province as the chief broadband candidate. Next in line are the Southern Province and Central Province appearing consecutively. The least potential broadband candidate appears to be the Northern Province. u The researcher identifies some models which have been used in other countries and these models were analyzed in terms of local context to check the applicability of those models to our communities. Conclusively, the study suggests appropriate broadband models that should be adopted by the communities. A new model is introduced by the researcher to the Western Province named "Service Provider Model (SPM)”. For the Southern and Central Provinces, “Passive Infrastructure Model (PIM)” was determined as the best model. For the North Western and Sabaragamuwa Provinces research study suggests implementation of the “Carriers Carrier Model (CCM)”. These models will be useful for the introduction and use of broadband services in the identified communities. The researcher further analyses the implementation of the PIM and suggests fiber as the most suitable backbone technology. The researcher recommends implementing fiber through the Railway line or Power Line. Also, in order to facilitate service providers to distribute broadband services to more under-served parts of the communities, the researcher suggests the usage of state lands through provincial councils. The report concludes by presenting several suggestions for the successful implementation of one ofthe recommended models.
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    item: Article-Abstract
    Environmental performance evaluation in supply chain
    (2015-09-01) Perera, PST; Perera, HSC; Wijesinghe, TM
    Environmental performance evaluation is an area of growing concern among the worldwide community. Consequently, measurements to evaluate environmental performance are of great importance. However, lack of a quantifiable model to study the environmental performance is a problem in this area. This study therefore attempts to quantify the environmental performance of supply chain of a manufacturing company, which requires evaluation of many criteria. Therefore, selection of environmental performance measures leads to a multi-criteria decision making problem. As a result, analytical hierarchy process is selected to develop the model and is solved with Expert Choice software. Finally the proposed model is applied to a case study company to identify the key areas of environmental performance of the company’s supply chain and to assess various product categories manufactured under those key areas.