Master of Philosophy (M.Phil.)

Permanent URI for this collectionhttp://192.248.9.226/handle/123/18714

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Now showing 1 - 6 of 6

item: Thesis-Full-text
Appraising a relationship between morphology and energy index of office buildings in tropics:
(2020) Jayasinghe WS; Rajapaksha I; Rajapaksha U
In the last few years, together with the surge in new construction, the energy demand from buildings has also been influenced by current practice on energy demanding mechanically controlled buildings with artificially lit interiors. Present urban development strategy of implementing Mega polis development plan for city of Colombo expands its boundaries of the urban building stock. Thus, it’s vital to explore the end use energy demand of national building stock and comprehend a relationship between building morphology and energy consumption. A walkthrough field investigation was performed in 46 Wards in Colombo Municipal Council region. The structure of the survey was organized in relation to geographical information system (GIS) data and land use maps of the CMC region. Data was collated to formulate a comprehensive database on morphology of office building stock comprising major physical parameters and energy indices. Results revealed the office building stock is primarily composed of Air-conditioned office spaces and of which 78% contains naturally ventilated common spaces. In this stock 53% and 13% of the office buildings have an annual average building energy index above 200KWhm¯² and 300KWhm¯² respectively. Linear shape dominates the plan form representing 70.2% of the stock. Other basic shapes such as square, circular and composites corresponds to 19.5%, 2.3% and 8% respectively. . 54.55% of the office buildings have an average BEI of 150-250 kWhm-². Out of which 37.03% of the office buildings are EW oriented. Nexus between building façade configuration and building energy index were further analyzed using multiple and simple linear regression analysis. The analysis was conducted for buildings in the identified energy index categories by considering all four orientations. EW and NS oriented buildings were considered for further investigation to evaluate the effect of aspect ratio on energy index. It is evident that aspect ratio of 0.70 (1:1.43) in 100-150 kWh-² energy index range was within the optimal range. The optimal aspect ratio for buildings along east west axis is within the range of 1.27:1 to 1.5:1. Further increase of aspect ratio beyond this range result in increase of energy consumption in buildings. The average aspect ratio for NS oriented buildings in 100-150 kWh-² energy index range was 1.49 (1.49:1), which was within the optimal range. Nonetheless, the average aspect ratio for NS oriented buildings in Average Range is 3.22 (3.22:1), which is beyond the optimal range. Further onsite thermal investigations in the selected representative buildings with deep and shallow plan forms revealed a clear indoor temperature difference during air conditioned and non-air-conditioned period. It is evident that deep plan form has a greater potential to control external heat gain and reduce end use energy demand. In contrary, shallow plan forms are more susceptible for external heat gain and higher temperature variation is evident periphery and core. Moreover, overheating building periphery in both shallow and deep plan forms are susceptible for overheating condition. Thus the findings of this study represent the criticality of building morphology based on plan shape, orientation and interior planning which demonstrate a significant impact on end use energy demand due to external heat loads.
item: Thesis-Full-text
Impacts of restoration of ulpotha micro-cascade in Galkiriyakanda cascade on environment and rural livelihood
Fernando, DJ; Manawadu, S; Gamage, D; Cooray, S
This dissertation identifies and analyses the restoration efforts of Ulpotha micro-cascade located in the Galkiriyakanda cascade. The ‘Case Study’ methodology was used for the research. A Conceptual Framework has been established (with five independent variables and one dependent variable) based on five hypothesis developed. The research question mainly focused on ‘positive changes and possible gaps in the Ulpotha restoration efforts’. Analyses in the dissertation include changes in forest, environment, hydrology and other socio-economic impacts on Walathwewa and Ihala Thimbiriyawa village communities who are dependent on it for living and livelihoods. The Galkiriyakanda cascade is located in the northern part of Kurunegala district. Galkiriyakanda stretches about 10 km and covers area of 1,106 hectares. There are about 1,500 households living around this cascade. Galkiriyakanda has many micro-cascades and Ulpotha is the major micro-cascade which is the main focus of this study. All most all communities live on agriculture and irrigated paddy is the main crop cultivate in the area. The cascade and communities faced many challenges during the recent past and degradation of cascade was the main threat to environment and rural livelihood. Research discusses in detail the impacts made by the rehabilitation efforts done in Ulpotha micro-cascade during 2004 – 2011 through Sri Lanka Australia Natural Resource Management Program (SLANRMP). Required information and data were collected through a Likert scale questionnaire and SPSS system has been used to analyse the data collected. Relationships between independent variables and the dependent variable have been analysed under five main hypotheses. The results of this study indicate positive impacts of the Ulpothe micro-cascade rehabilitation towards physical environment, livelihood and rural economic development. Findings of this study will help administrators, policy makers and rural development planners to expand and replicate this development model to other dry zone cascades as well. In addition, another important area of hydrology and indigenous irrigation in cascade was also identified as potential research areas for PhD studies.
item: Thesis-Full-text
Development of a theoretical framework to facilitate creative process in architectural design education
Gunarathne, ANCKW; Wijesundara, J
Creativity is the key for a progressive human evolution. Our creative ability places us as the superior species on earth. The need to be creative is felt within every industry and construction industry being engaged with original products finds it more challenging. Architecture is an art. It is not mere art it is an art of science, art of technology, predominantly an art of social existence. Architectural residuals possess the ability to recite the legends of vibrant societies that prevailed, the economic conditions, aesthetic sense and the technological advancements of a particular era. As with many other professions within contemporary competitive consumer society finding creative solutions is vital for its survival. Education is the key to foster creativity and developing strategies are based on theoretical understanding. However creativity being studied by different disciplines the research literature on theory is rich in both depth and breadth. Looking into creativity theories it reveals that fostering creativity in education posits its roots on considering the socio-cultural, cognitive-psychological, neuropsychological, neurobiological understanding as well as developing person-oriented, process-oriented and product-oriented approaches. Being placed at the highest level in each education domains creative interventions are essential in education programs to achieve creative outcomes. In developing creative interventions one needs to develop a theoretical framework to base its model. This requires understanding the domain specific influencing factors and the demanding orientation. Within architectural education design studio i? a key in nurturing creativity and it is organised into a process. Therefore the study explores the impact of strengthening of the creative process as a strategy to develop an intervention where the pertaining theories are assembled into an integrated theoretical framework termed "theoretical model of creative design process". The student performance in an interior architecture module was carefully investigated. Research design is an action research method where data is generated through a series of task performance. It was revealed that there is a significant relationship between the performance in creative process phases and design performance while the design mark after the intervention shows a significant improvement. Creativity is the key for a progressive human evolution. Our creative ability places us as the superior species on earth. The need to be creative is felt within every industry and construction industry being engaged with original products finds it more challenging. Architecture is an art. It is not mere art it is an art of science, art of technology, predominantly an art of social existence. Architectural residuals possess the ability to recite the legends of vibrant societies that prevailed, the economic conditions, aesthetic sense and the technological advancements of a particular era. As with many other professions within contemporary competitive consumer society finding creative solutions is vital for its survival. Education is the key to foster creativity and developing strategies are based on theoretical understanding. However creativity being studied by different disciplines the research literature on theory is rich in both depth and breadth. Looking into creativity theories it reveals that fostering creativity in education posits its roots on considering the socio-cultural, cognitive-psychological, neuropsychological, neurobiological understanding as well as developing person-oriented, process-oriented and product-oriented approaches. Being placed at the highest level in each education domains creative interventions are essential in education programs to achieve creative outcomes. In developing creative interventions one needs to develop a theoretical framework to base its model. This requires understanding the domain specific influencing factors and the demanding orientation. Within architectural education design studio i? a key in nurturing creativity and it is organised into a process. Therefore the study explores the impact of strengthening of the creative process as a strategy to develop an intervention where the pertaining theories are assembled into an integrated theoretical framework termed "theoretical model of creative design process". The student performance in an interior architecture module was carefully investigated. Research design is an action research method where data is generated through a series of task performance. It was revealed that there is a significant relationship between the performance in creative process phases and design performance while the design mark after the intervention shows a significant improvement.
item: Thesis-Abstract
Human exposure to street level air pollutants in Colombo and exploration of mitigation options using CFD modeling
Perera, GBS; Emmanuel, MPR
Human exposure to street level air pollutants in Colombo and exploration of mitigation potions using CFD modeling was studied. To fulfill the requirement, present study was designed to gather baseline air pollution data, health risk assessment data and computer modeling was subsequently applied to a selected urban area and urban school to minimize the air pollution. For the purpose of estimating the air quality effects of land use and planning variables, a free-ware model named ENVI-met was used. ENVI-met is a numerical, 4 dimensional (three spatial plus the time dimension) microclimate free ware model which can simulate the microclimate within street canyons through the solution of the physical basic equations for the wind current, the thermodynamics and the radiation balance of surfaces. In order to estimate the effect of land use and urban planning variables, several ENVI-met simulations were run: change of street vegetation, change of soil conditions and building geometry. Measured Respirable Particulate Matter (RPM) values were used to calibrate the simulation cases. It was found that the high risk urban location had RPM of 437~glm3 whereas low risk village had 212~glm3. Total Suspended particulate mater (TSP) levels during peak hours (7.30am-8.30am and 2.00pm- 3.00pm) exceeded the Sri Lankan standard (>538 ug/m ' against 500 ug/nr') ..The data also revealed that apart from the number of vehicles, meteorological factors such as high temperature and low relative humidity increased the Respirable Particulate. Matter. A significant different in aerosol exposure levels was resulted in urban and rural dwellers for S02 and N02. Similarly exposure levels of urban & rural school children were resulted for S02 and N02. Simulations carried out at the urban area and school area clearly showed that the increasing greenery and banning of vehicles from busy sub roads with paving resulted the decreasing of particulate matter concentration. On the other hand, high rising buildings resulted the increase of particulate matter concentration heavily in the urban area and urban school respectively. Compared to the Base Case, results have shown that marked decrease of PM concentration has occurred by the suggested Best Case and for the Worst Case considerable increase of PMIO concentration in the urban area and urban school respectively. Best city design with minimum air pollution can be modeled using the ENVI-met computer modeling software with minimum cost. Therefore possibility of using this model in planning stage of new cities as well as redesigning of cities is highlighted.
item: Thesis-Abstract
Value management based IT procurement model for construction organisations
Karunasena, GI; Perera, S
Lack of effective IT exploitation in construction organisations often create difficulty in justifying future expansion and use of benefits of IT innovations. The problem of identifying best IT products, procurement approaches, costs and benefits is one reason behind that. It is a global problem experienced at all types of business sectors and organisations. However, it is more acute in the construction industry as a result of its structure, fragmentation and under capitalization. A recent article by Central Unit of Procurement, UK states, everybody benefits from fast, effective and transparent procurement. It reduces supplier cost, enables the organization to fulfill commitments faster and more effectively and gives better value for the client's money. This necessitates existence of a tool to identify best-valued procurement options and provide feedback on their probable successes or failures. Therefore, the primary aim of this study is development of Decision Support System for construction organisations to assist in IT procurement capable of increasing customer satisfaction while eliminating unnecessary expenditure with value management principles. Value management is an organized approach providing necessary functions at the lowest cost. For development of the model, theoretical considerations and current industry practices were reviewed to synthesize a new approach drawing from the best practices of procurement in construction industry. This new approach also incorporates principles of value management in selecting the best procurement route. The selection was then modeled into an Object Oriented information model allowing users to make intelligent and informed decisions on procurement routes. It was then tested with real life IT procurement scenarios and refined accordingly. The evaluated model was enhanced as a Computer Aided Decision Support tool providing a user-friendly guide for IT procurement in construction organisations. The research samples comprised of experienced academics and industry representatives, all with direct experience in IT based systems within construction organisations. The research established need for a new approach to assist IT procurement in construction organisations. Moreover, no satisfactory IT procurement method for individual construction organisations was discovered. The developed Decision Support Model provides an interactive and automated system for procuring IT in timely manner with the best value. The model has been designed to help users to understand procedures, merits and demerits associated with ranked list of best valued procurement methods that can be used to procure IT for identified IT solutions and IT procurement requirements. The model is targeted at the senior management level, particularly those without much knowledge in IT procurement, but responsible for such. The model is effective in satisfying established objectives and requirements of construction organisations, eliminating deficiencies in IT procurement. The main benefit expected from IT procurement model is assurance of best value, cost savings and better performance in procurement process encouraging enhanced investments in IT. KEYWORDS: Information Technology Procurement, Value Management, Construction Industry, Procurement Model, IT Solutions, Decision Support System
item: Thesis-Abstract
Study of the relationship between construction sector and economic growth in Sri Lanka
Ramachandra, T; Rameezdeen, R
Many researchers have found that the construction industry is always been closely related to the national economy. This study investigates the relationship between construction sector and the economy of Sri Lanka in three different ways as follows; the causal relationship, change of economic policies, and linkages using data from Sri Lanka over the period of 1950-2004. The relationships were primarily found through secondary data analysis using Granger causality, Policy archetypes, and Input-output analysis. The results of the Granger causality test shows that the construction In capital formation causes GDP and not vice versa. This could be justified for a developing country like Sri Lanka as it is essential to have high rate of investment for rapid economic growth, and as construction constitutes around 50% of this investment, it is expected that if there is a growth it must be accompanied by a rapid expansion of activity in the construction sector. Further, the results show that construction leads GDP by one year as in general construction product takes one to two years to procure. Further, the study proves that the relationship between the policy regimes and the economic growth and construction growth is significant. When policies are "interventionist cluster" type it showed less economic growth and construction growth. That is when the government involvement is high in economic activities, they neither supported construction sector nor the overall economy. On the other hand, Non-interventionist general type could be attributed to high performance in both construction sector and economy. This is true because when government influence on taxes, regulatory measures are loses, it attracts private sector investors and thereby it favoured construction sector and the overall economy. In Sri Lankan economy the period of 1956-1965, and 1970-1977 characterized as interventionist cluster type caused very low growth in construction. The period of 1965-1970 showed highest growth in both construction and economy due to implementation of major developments. In addition, increase loan limit, number of land acquisitions also caused increased growth. The period of 1948-1956 agriculture based economy with less government involvement (non-interventionist sector) recorded high growth in construction due to the significant amount of public investment in irrigation, colonization schemes, government buildings such as schools, hospitals and other projects related to development of economic and social infrastructure. The research reveals that the construction sector indicates an above average, significant backward and forward linkage in the forty-eight sector economy of year 2000. In Sri Lanka, the backward linkage indicator ranges between 0.364-0.457 during the period of 1970-2000 while output multiplier ranges between 1.496-1.641indicating that the "pull effect" of the Sri Lankan construction sector. The "push effect" has been very insignificant until 1995. However, in year 2000, it significantly increased indicating the development of repair and maintenance sub sector. An aggregated sectoral analysis reveals high dependence of construction on manufacturing followed by services. The trend analysis shows an increasing dependence of construction on the services sector. The direct and total inputs from manufacturing and services have increased over time. Keywords: National Economy, Granger causality, Tnput-output Analysis, Construction Sector, Backward and Forward Linkages, Linkages, Sri Lanka

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