Thesis & Dissertation

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University of Moratuwa Theses and Dissertations by University of Moratuwa, Sri Lanka is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at www.lib.mrt.ac.lk.

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item: Thesis-Abstract
110V universal battery charging panel using pic microcontroller
Vijithananda, SK; Karunadasa, JP
Conventional power electronics and electronic control circuits have been replacing by the intervention of the microprocessors/microcontrollers in modern industrial applications. This is mainly because with their applications the whole systems becomes more and more compact while enhancing the durability. On the other even with the more robust applications hand more accurate & fine operation could achieve by using such modern programming devices. This project was origin from based on an actual requirement of designing (10v battery charging panel (to energize the batteries in spring charge type breakers)for electrical engineering division of Jaya Container Terminal(J.C.T) of Sri Lanka Ports Authority. But this technique would use to not only to charge batteries of spring charge breakers . but also batteries widely use in YHF communication hand held sets, explosive detectors, emergency lamps, etc.... Rechargeable batteries are vital to portable electronic equipment such as laptop computers and cell phones. Fast charging circuits must be carefully designed and are highly dependent on the particular battery's chemistry. The most popular types of rechargeable batteries in use today are the Sealed-Lead-Acid (SLA), Nickel-Cadmium(NiCd), Nickel-Metal-Hydride (NiMH), and Lithium-Ion (Li-Ion). Li-Ion is fast becoming the chemistry of choice for many portable applications because it offers a high capacity-tosize (weight) ratio and a low self-discharge characteristic .Depending on the battery chemistry the charging characteristics of a battery differs to each other. In this project simply what I have done is allows the particular battery to follow its charging characteristic curve when they where you could not find in conventional charging techniques. The charging process is controlled by the software program microcontroller (PIC16F876).Since the battery chemistries are different for different types of batteries, several sets of programs would have to written to the controller for each battery given by the manufacturer. There are some theoretical design calculations included for designing of power electronics modules. DCDC converter, square pulse generator, single rail power & dual rail power supplies,(etc..) Calculations have been done based on highly theoretical facts. Therefore some practical observations are tends to differ from the theoretical approach. Most of the theories studied in the power electronic lessons of my M.S post graduate were widely used in doing above mentioned designs. At the beginning the actual target was to built a battery charging panel of 110V,tut due to some limitations of purchasing of high capacity transformer which suit to this application ,the project was limited to 40V panel only. But the concept, approach & the guide line would be more or less same for the more advanced systems also.
item: Thesis-Full-text
2D - 3D Hybrid perovskites for perovskite solar cells
(2020) Gunasekara HKYPG; Sewvandi GA
Hybrid Organic-Inorganic Perovskites (HOIP) have been studied extensively and grown popular. Especially in Three-dimensional (3D) Perovskites, achieving power conversion efficiency (PCE) exceeds 23%. Nevertheless, some of the morphological imperfections will limit their structural capabilities. Pinholes in discontinuous perovskite films induces the huge leakage current which can cut down the device efficiency and creates a short circuit. Therefore, it is essential to deposit a compact film with passivated defects. Two-dimensional (2D) halide perovskites, conversely attracted significant attention and become a positive alternative with their uncomplicated synthesis, stability, and excellent photoelectric properties. This study, investigates the formation and properties of 2D Tetrabutylammonium lead halide (TBAPbBrxI3-x) HOIP. Tetrabutylammonium ion is a large cation, and more likely forms a 2D perovskite structure which was confirmed by the XRD spectrum. Substantiate by SEM images, TBAPbBrxI3-x establishing and favors crystals with enhance orientation and few grain boundaries and. However, the absorption spectra of the film shows an excitonic peak at 411 nm and a clear band edge at 450 nm. Resulting in poor absorbance in the visible range, with optical band gap of 2.76 eV, narrowing the ability to use TBAPbBrxI3-x alone in solar cells. Conversely, TBAPbBrxI3-x can use as separate capping layer on the top of 3D perovskite layer, enhancing the properties of the 3D perovskite layer. Incorporating TBAPbBrxI3-x into CH3NH3PbI3 shows a better film formation with few holes. The application of mixed perovskite layers incorporated solar cells will result in better structural and optoelectronic properties.
item: Thesis-Abstract
2D Human animation synthesis from videos using generative adversarial neural networks
(2022) Udawatta PN; Fernando S
Synthesizing 2D human animation has many industrial applications yet is currently done manually by animators utilizing time and resources. Therefore, many types of research have been conducted to synthesize human animation using artificial intelligence techniques. However, these approaches lack the quality as well as capability to generalize to various visual styles. Thus, synthesizing high-quality human animations across different visual styles remains a research challenge We hypothesize that given video references for motion and appearance, synthesizing high-quality human animations across a variety of visual styles can be achieved via generative adversarial networks. Here we have come up with the solution known as HumAS-GAN, an acronym for Human Animation Synthesis Generative Adversarial Networks. HumAS-GAN accepts video references for motion and appearance and synthesis 2d Human animations. HumAS-GAN has three main modules, motion extraction, motion synthesis, and appearance synthesis. In motion extraction, the motion information is extracted via pre-trained human pose extraction [21], The motion synthesis module syntheses a motion representation matching the target human’s body structure which is then combined with the human pose coordinates to be used by the appearance synthesis module to generate the Human animation. HumAS-GAN is focused on improving the quality of the animation as well as the ability to use cross-domain/visual-style references to generate animation. This solution will be beneficial for many multimedia-based industries as it is capable of generating high human animations and quickly switching to any visual style they prefer. HumAS-GAN is evaluated against other methods using a custom dataset and a set of 3 experiments designed to evaluate the capability of generating human animations across various visual styles. Evaluations results prove the superiority of HumAS-GAN over other methods in synthesizing high-quality 2d human animations across a variety of visual styles.
item: Thesis-Abstract
3 Dimensional visualization of code smells
(2022) Hasantha PAC; Wijesiriwardana C
Bad code smells are symptoms of design flaws in source code. Several tools and approaches have been proposed for detecting and visualizing code smells. To maintain the software quality, prioritizing the identification and removal of code smells are required. Identifying the code smells using visualization will helpful developers to understand and refactor the code. This study proposes a novel 3D metaphor to detect and visualize code smells by using a combination of the code city and island metaphor visualization techniques. Proposed model identifies and visualizes the code smell at different abstraction levels in a proper understandable aspect. This model evaluates by using several open source software projects and visualizing the detected code smells in abstraction levels such as classes, methods. The proposed model will allow for more research into code smell visualization and it will keep better focus on the needs of developers
item: Thesis-Abstract
3-Dimensional spatial channel model for multi-storeyed indoor environments
(2021) Tennakoon TMP; Wavegedara KCB
A three-dimensional (3-D) geometry-based stochastic model (GBSM) is presented for various types of multi-story indoor environments. The proposed model assumed that the scatterers are distributed within a spheroid, where the transmitter and the receiver are located at the focal points of the spheroid. The proposed model provides the probability density functions (PDFs) of the angle of arrival (AoA), the time of arrival (ToA) and the spatial correlation coe cients correspondence with several channel parameters of the channel. By considering non-uniform scatterer distributions, the spheroid GBSM is extended for multistory indoor environments. Closed-form expressions are derived for the joint and marginal PDFs of the AoA in both the elevation and azimuth planes and the ToA. The analytically-derived PDFs of the AoA and ToA obtained for Gaussian and Rayleigh scatterer distributions are compared against those obtained from the ray-tracing simulation of typical indoor environments. The standard deviation values of Gaussian and Rayleigh scatterer distributions are chosen to provide the best possible approximation to the PDFs of the AoA and the ToA obtained from simulation. Our results clearly indicate that the analyticallyderived PDFs of the AOA and the TOA for Gaussian and Rayleigh scatterer distributions are in much closer agreement with those obtained from ray-tracing simulation than for uniform scatterer distribution. However, analytically-derived PDFs of the AOA and the TOA for Gaussian scatterer distribution show closest agreement with those PDFs obtained from the simulations. A generalized 3D channel model with an arbitrator scatterer distribution point is proposed based on the spheroid GBMS. The proposed channel model is assumed that the scatterers to be distributed according to the Gaussian distribution about an arbitrary point within the spheroid. Closed-form expressions are derived for the joint PDFs of the AoA, marginal PDFs in both the elevation and azimuth planes, as well as for the marginal PDF of the ToA. Numerical results are utilized for the veri cation of the derived-closed form mathematical expressions. More-over, the obtained marginal PDFs of AoA and TOA are compared against PDFs obtained from the simulation of an indoor environment using ray-tracing tool. By choosing a proper scatterer distribution center point based on the actual indoor propagation environment and a suitable value for the standard deviation of the scatterer region, the proposed 3-D model of the channel can be exploit the performance of the wireless communication technologies and systems in indoor environments. The spheroid GBSM is extended to a 3D geometry-based spatial correlation model for multiple-input multiple-output (MIMO) communication environments. Approximated closed-form expressions are obtained for the normalized spatial correlation coe cients of frequency non-selective Rician fading channels. As a special case, the normalized spatial coe cients are derived for Gaussian scatterer distribution. Closed-form expressions developed are veri ed by the simulation results obtained using the WINNER Phase II channel model (WIM2). Furthermore, the capacity performance of MIMO channels is investigated using the proposed geometry-based correlation model. Our results have clearly demonstrated that the proposed 3D spatial correlation model can be used to investigate the performance of the frequency non-selective Rician or Rayleigh fading MIMO channels with di erent antenna con gurations accurately.
item: Thesis-Full-text
A 3D models of human ejaclulatory ducts
Gunasekera, CL; Dayananda, N
Benign Prostatic Hyperplasia (BPH) is a common non-malignant ailment effecting in ejaculatory duct of aging men. BPH induces bothersome lower urinary tract symptoms. The standard treatment for BPH is Transurethral Resection of the Prostate (TURP), which mitigate urinary symptoms and enhance urinary flow. Smooth sphincter of the bladder neck accumulates and resides seminal fluid as it reaches the prostatic urethra before it ejects during ejaculation. Retrograde ejaculation occurs due to removal of this smooth sphincter of the bladder neck during TURP. Hence, about 53-77% patients develop retrograde ejaculation after the procedure. The research has shown that preserving the portion of supramontanal prostatic tissue during TURP leads to preserve antegrade ejaculation in about 80% of patients. The accuracy of this surgical procedure could be enhanced by the aid of 3D modelling. A literature survey on the existing procedures for model construction indicated that further improvements could be achieved through reconstructing a 3D model. A 3D model will enhance the understanding of the anatomical relationship of the ejaculatory ducts and prostatic urethra in cross sections of the prostate gland and to determine a safe zone with the prostate to remove without damaging the ejaculatory ducts. We used photographic images of prostates obtained from male cadavers above the age of fifty years. The prostate samples fixed on to a wax block and uniform 2 mm thick slices were removed sequentially while taking photographs with a digital camera. Major steps in constructing a 3D model from the acquired images include: image registration to align series of slices, segmentation of the prostate, urethra and ducts and 3D modelling of the segmented structures. A simple landmark based image registration technique was employed by manually selecting points along the four edges of the wax block and automatically detecting the vertices of the block using intersections. Then rotation, translation and scaling were estimated on individual slices to align all the slices. The prostate was then segmented manually using an existing software tool program. The ejaculatory ducts and the urethra were segmented using a simple active contour based segmentation tool. Finally, a 3D mesh model was developed using boundary points of each of the segmented structure. The following three surgically important measurements calculated using to the model: the angles of the centre of the left duct, to the centre of urethra and to the centre of right duct, perpendicular distance from the centre of urethra to the line joining the two centres of ducts, and width of the prostate. Results showed a large angle both proximally and distally, 3D relationships of ejaculatory ducts and urethra depended on the maximum width of the prostate. During TURP, safe distances to resect the prostate without damaging the ducts are calculated based on the maximum width of the prostate. Depth can be safely resected without damaging the ejaculatory ducts. In the future, it is quite essential to test these results on clinical grounds.
item: Thesis-Abstract
3D Reconstruction of objects from RGB images and depth information using deep learning
(2022) Karunanayaka TD; Chithraranjan C
Object reconstruction is the manner of producing a computer model of the 3D appearance of an object from two-dimensional photos. It's the opposite procedure of obtaining 2D photos from 3D scenes. 3D reconstruction of objects from their digital pictures is a time-efficient and convenient manner of analysing the structural features of the item being modelled. Currently there may be an essential need for 3D content for computer graphics, virtual reality and communication, triggering an alternate emphasis for the requirements. Many present methods for constructing 3D objects are built round specialized hardware resulting in a high fee, information scanning barriers due to environment conditions which can't satisfy the requirement of its new programs. The art of three-dimensional reconstruction of objects and scenes has been a broadly researched topic. In this Master’s thesis, I proposed to address the above problems by developing a Deep Learning approach to reconstruct the object. This type of approach does not depend too much on the environment condition and the cost is low. However, the proposed method mostly targets the reconstruction of objects other than reconstruction of scenes. This research attempts to develop a Deep Learning based 3D reconstruction method for objects to avoid the limitations of the current 3D reconstruction approaches.
item: Thesis-Abstract
A Benchmark for web services
Wickramage, N; Weerawarana, S; Dias, G
Even though there are several benchmarks developed to measure the performance of Web service frameworks, the general tendency of them is to simulate only theoretical scenarios such as streaming homogeneous data structures like arrays. On the other hand, the computer industry has an established culture of developing performance benchmarks imitating not only imaginary situations but also real world scenarios. This dissertation discusses whether it is quite necessary to test the performance of web service frameworks against such benchmarks that closely reproduce real world situations. This discussion is based on results obtained by running two benchmarks (namely one replicating 12 different real world scenarios that are optimum candidates for web service applications and another only simulating a theoretical situation) and concludes that the real world type Benchmark represents a reasonable subset of actual scenarios because the ranking of the leading Web services frameworks is consistent with Industry wide opinions [22] while statistically reaffirming the significance of using real world type benchmarks. Additionally, this dissertation identifies complexity of the SOAP messages involved in Web service transactions and size of the payloads those messages are carrying as two major factors that affect the round trip time of the SOAP messages and reveals that a framework that is good at handling complex SOAP messages may not deal with the messages that are carrying larger payloads equally well and provides statistical proof for that.
item: Thesis-Abstract
A Changing profession : the role and function of the master builder in the practice of contemporary architecture
Kumarage, AI
What will the role of the architect be in the twenty-first century, as there are greater and greater challenges in the present building industry. The architect, in the late twentieth century has developed skills to handle these complex problems of the future, becoming an administrator and, in the change from a production to an information society, an information administrator. The architect has lost the hand- on skills of the craftsman, but is skillful in delegating tasks to a multi headed team to bring information from hundreds of components. The architect is as adept as an assembler of manufactured parts. As the twenty first century approaches ,it is important that the architect, who become an administrator, delegator, and assembler of parts, recognize with trepidation the erosion of the profession's essential being, that of the designer. The architect is the one professional component who can act the part of humanist with regard to density of site and scale for the pedestrian, who can envision great site composition, who knows what ceiling, floor, and mechanical system can yield real integrated quality, and who chooses the color of the motar of the brick joints, the joints of the precast, the shape of the hand rail, and the proportion of tread to riser. The architect, who walks in to the twenty first century, or the twenty-second century for that matter, should give up these choices with great reluctance. It is imperative that architecture retains its important heritage and ascendancy with pride and conviction as the profession uniquely qualified to build the peaceful civilization of the future.
item: Thesis-Abstract
A Comparative study of traditional and contemporary settlement patterns in Sri Lanka with special reference to Kurunegala District
Jinadasa, KN
The concept of a settlement is the place for living together as a group. Therefore the arrangement of the, settlement can be identified as the altered environment to ensure the spread of development efforts and the quality of life in a more. complex manner for a large group of people. In Sri Lanka, traditional settlements were able to fulfilled these objectives as a community. They built their house on a trial and error basis to satisfy their requirements noted on their own imagination and their own calculations. Traditional house is an architectural solution without professional architects. Traditional house was an answer to the multi faceted social , environmental and technological forces of their own societies. Continuity of the form also have made a reasonable contribution evolving repetitions. Thus the whole settlement has a certain character according to their living pattern since , social ,technological and environmental factors are localized. The house type varies from society to society, bringing in regional variations. The need for housing existed for ages but became a problem when it was unable to fulfill user needs and desires satisfactorily for the solution to the issue of housing in the resent past. As a result new form of housing have been forced into rural setting disregarding the continuity of tradition. Because of the magnitude of the problem and its sympathetic nature , eventually forced housing projects introduced to solve that problem. In this case the government becomes the paying client to the architect and the actual user becomes the voiceless user group. They have no chance to sound their actual needs . Therefore forced house does not fulfill the social environmental and technological needs of the rural society. Therefore it is important to understand problems arisen in forced settlements specially in comparison with traditional settlements which was extremely compatible.
item: Thesis-Full-text
A Conceptual design for a tower type concentrating solar power plant near Hambantota
Wijayawardhana, NABR; Wijayapala, WDAS; Fernando, DGR
In this study the basics of a central receiver type solar thermal power plant including a thermal storage are studied. Further, the technical feasibility of a central receiver type solar thermal power plant near Hambantota is investigated. The requirement of a power plant and the size of the plant are determined. The availability of solar resources in the area and the best area to locate a solar thermal power plant is also studied. The other required resources such as water, lands, proximity to transmission lines are taken into consideration. Further the impact on the environment and the possible measures to mitigate such impacts are examined. In addition, the technical features of a central receiver type power plant are studied and a conceptual design for such a power plant has been developed. In the conceptual design, the total required number of heliostats or reflectors, the heliostat field layout, the receiver size, the thermal storage size and the tower height have been determined. Finally, the economic feasibility of the plant is checked considering the available soft loan facilities which can be obtained from international development banks such as Global Environmental Facility (GEF), World Bank and Japan International Cooperation Agency (JICA). The economic benefits from the Carbon credit program have also been taken into account. Finally, it is concluded that certain cost reductions and economic conditions are required for the project to be viable
item: Thesis-Abstract
A Critical analysis of selected regulatory provisions for persons with disabilities in the built environment with special reference to Sri Lankan situation
Jayasinghe, JAAM
Architecture is the thoughtful structuring of places to inhabit. It is to create an environment that will generate a particular activity pattern required by a set of users to achieve their goals. Any conscious change in the environment with or without a built structure, which leads to man's physical and psychological well being may termed as "Architecture". "Architecture is the process and the product of human habitation. It is the only art that caters to physical needs- shelter and bodily comfort. It is the only art that encompasses all his psychological needs, privacy, security, identity, aspirations, self expression".(Habraken, 1985)Architecture is primarily a spatial experience. It incorporates all other arts in presenting this experience: the rhythm of music, the movement of drama. It differs from all other arts in the way it presents its experience. As Meiss (1990) points out music, drama, painting, sculpture also have their spatiality, but it is defined from exterior, offering only the possibility of mental presentation. Architecture is the art of hollows; it is defined both from the interior and from the exterior; walls have two sides. One penetrates it with one's mind as well as body. Every person is sensitive (in varying degrees) to the built environment he lives in. He creates it, modifies it and changes it constantly. The built setting, too, modifies him, changes him, their behavior. It can be life suppressing or even crushing. It can be life enhancing and mind purifying too. This is a reciprocal process, the end result being essentially a change in man. But what kind of changes does it makes in him? As Christoper Day (1990) points out, built environment is potentially a dangerous tool. It can be used to manipulate people. It can make people feel ill. Therefore the purpose of Architecture is to create a space, psychologically and functionally conductive. Development of whole person physically, mentally, emotionally is the areas that an architect fulfills his user. Architecture brings out the vital relationship between man and the built environment. If the relationship is ill matched, it could have ill effects on the user. It could nnoy and irritate the user all the time. Nature has been created impartially to every body, but man has created partially among himself by constructing buildings, roads, houses without considering the disability, that may occur to any body at any time, Disability is a subject, we are slowly beginning to face. No population is exempt from disablement. Every one is at risk, all the time. Any person can become disable during his or life time. With the development of modern technology, it was anticipated that the number of disabled persons would decrease, but unfortunately it is on the verge of increasing. For example war, drug and chemical fire arms, industrial hazards can be considered. A study done recently estimate that some 8.5 million disabled persons are added annually to the global figure or 23200 a day. Unfortunately this population is so helpless. They need opportunities to participate in the busy life of the world, to be involved to do the same sort of things that other people do.
item: Thesis-Abstract
A Critical evaluation of the e-government model implementation in Sri Lanka
Wackwella, GCDN; Weerawarana, S
For a successful e-government implementation, having a well-organized e- government model is a must for any country. It cannot be a model, which can be copied straight from a different country. It should significantly impact all sectors of the country's economy and its society and should be molded according to the unique characteristics of the country./ This research will critically evaluate the e-government model, adopted by the ICT Agency of Sri Lanka with its e-Sri Lanka Re-Engineering Government programmed. It will evaluate its strengths and weaknesses by analyzing factors that influence e- government projects currently being implemented. Based on this factor analysis, appropriate recommendations will be proposed to enhance and strengthen the Sri Lankan e-government model by considering all social/cultural/economical/technical aspects pertaining to Sri Lanka.
item: Thesis-Abstract
A Critical examination of new materials and technology on architectural expression
Disenka, SPC
"To believe that one can attain beauty by untruth is heresy in the practice of art ..... "(1) "In architecture, the question of truth and untruth refers to the relationships between form and construction or between form and content" (2)"The fusion of these two elements is the absolute aim of all great art . The simplest example is offered by poetry which cannot exist without the close association or the magic symbiosis of sound and meaning". (3) The above statements strengthened the fact that a built form and a choice of materials& construction systems should have a close relationship ,as such an arrangement will facilitate full realization of the meaning of such a built form . This meaning attribute has to be regarded as the dominant element of the built form and one that breathes vigor and vitality into it and helps to ensure its survival. The role of materials and technology is to provides the physical entity for this meaning .Since the expression is visible aspect of this meaning, materials & technology act as a media of architectural expression .Therefore in the creation process of architecture there are two distinct ends come in to play harmonizing with each other. Materials and technology: Architectural Expression An important point to note is that Industrial Revolution in Europe in the 15th century ,has actually served as a strong stimulus to the growth and expansion of building industry. This situation has in a sense created a great change in this relationship, and therefore it impacts on architectural expression. New technical innovations gave designers a new opportunity of designing buildings ,using new materials which in turn generated better conditions , for ensuring that the built form carried the appropriate meaning and expression .Not with standing the above, the principle point to note is that this situation has also created new trends on the score of as to whether those new technical innovations would really meet a successful architectural entities. "The sources of the visual vocabulary of structural technology which is used in high tech architecture are various and for the most part. not architectural . They occur in the world of 'pure' structural engineering -principally in long -span bridge building -and also in the vehicle technology and aeronautical engineering fields" (4) "The dual investigation has brought me to the conclusion that a technically perfect work can be aesthetically inexpressive. Good technology seems to be a necessary though not sufficient condition for good architecture". (5) Therefore in this situation it can be said that new materials and technology has created a dual impact on architectural expression. The following study is a detail examination of this impact .In this situation I regard this subject I have under taken as an exciting challenge to probe into a field that is both complex and rich and from which certain valuable impressions and conclusions, could be drawn. It is important to note that If I had more time I could have gone into more detail in this examination.
item: Thesis-Abstract
A Critical examination of traditional spaces in high desity housing and neighbourhoods
Athuraliya, P; Nammuni, VS
Man is a conscious animal, who tends to respond directly to his surrounding environment. He eventually converses with his surroundings. He features and event respond to and reacts against them, thus making him self of that environment. In other wards he always tries to adjust him self for new experiences of different places. It is believe that the transitional spaces is the environment help him in this adjustment.According to the Oxford dictionary transition is "passage or change from one place or state or act or set of circumstances to another" spaces which allow such changes to take place could thus termed as "Transitional spaces". They denote a "change of condition" from one situation to another imposing an important psychological effect on people existence of a "Transitional space" has been considered as are of the essential features, where two different qualities in environment are happened to marry. In place where such transitional spaces are lacking or poorly designed, enormous pressures are found to be brought on the user and on this activity pattern as well. Urban high density housing and neighborhoods is one such examples in which this phenomenon is apparted. Growing urban population and increasing land value has become the major contributing factors in this deprivation of transitional spaces. Every square inch of land is found to be valued in terms of rupees and cents leaving the quality of the place and comfort of the user totally ignored. This study thus aims at examining the value of transitional spaces as a mean of creating a "successful" neighborhood. Further in attempts to point out ill effects of deprivation of such spaces for the mere purpose of achieving benefit in monotony other quantitative terms
item: Thesis-Abstract
A Critical review of mobilization advance payment and contractors' cash flows
Wijekoon, WMCLK; Perera, A
This research addresses the determination as to whether the Mobilization Advance Payment is actually necessary in the Sri Lankan construction industry, its effect on contractors' cash flow and whether it is a motivation for the contractors. Accurate cash flow forecasting is essential to all contractors in the construction Industry for successful operation and existence in the long run. At initial stages of a project the cash flow aspect of the contractor is negative. The main role of project financing is to cover up this negative flow in a beneficial, cost effective manner. Mobilization Advance Payment enhances the quality and productivity in the construction industry. It improves the performance and cost efficiency of the contractors as well as the clients. Cash data in relation to thirty projects were collected. Three criteria, no Mobilization Advance, 20% of the initial contract sum as the Mobilization Advance paid at the inception of the project and 20% of the initial contract sum as Mobilization Advance given in stages, were identified to determine the differences in the effects of cash flow. The effect of these different criteria on the cumulative cash flow was examined. Further Scheduled Performance Index was calculated for further analysis. Results show and confirm that Mobilization Advance Payment has a big bearing on the contractors' existence and their motivation towards attaining objectives of the project. Research confirms that Mobilization Advance Payment is a necessity in the Sri Lankan construction industry. Further it can be confirmed that the provision of Mobilization Advance Payment is very essential for the Sri Lankan contractors. Key Words: Mobilization Advance Payment, Cash Flow, Stage Payments, Scheduled Performance Index
item: Thesis-Abstract
A Critical study of role of colours in generating architectural space
Piyasena, NMN; Dayarathna, R; Perera, LSR
The primary purpose of art is convey an appropriate message to the preceiver through the expression of feelings. Therefore architecture which is its sublime from fulfilling there requirements becomes an art. As an art, architecture provides the back-drop to convey the appropriate message to create meaningful spaces which are identified as architectural spaces.Every living organism requires space for its existence. Therefore the framework provided for their existence is considered as the dimensions of living things. Space can be limited or unlimited. Limitless space around us is considered as infant space. When the space is bounded by natural or man made limitations it becomes realistic. Space could be considered as the major force, evoking or conditioning the human mind. It provides not only the participant or the user with adequate physical movement but also create emotional satisfaction. The emotional satisfaction of the percevior could be achieved through the meaningful articulate inside the space. It helps the observer in preconceiving spaces in their true perspective. That means it communicate the appropriate message to the participant thus creating the derived environmental quality within the particular space.Therefore architecture mainly consider with qualitative needs while filling the quantitative needs. The environmental quality in architectural space is determined by several factors. That is form, scale, proportion, interrelation of spaces, objects inside, and the way how these factors blend with each other. Quality of an architectural space is also affected due to expression of visual surfaces of enclosure planes and objects and their interrelationship to each other. Most effective visual property of the surface is its color, its light and its texture. However the way people perceive or respond to the environment emotionally or spatially depend on their physiological nature, personalities, their cultural and social backgrounds and the environment itself. Color can be regarded as one of the visual properties of surfaces and also can be experienced through the sense of vision. It is also known as the character of the surface or enclosure planes within a space character of form. Various colors can be achieved in different ways such as the way that materials are manipulated using color pigments on a surface. Color can be identified both in nature as well as in man made environment.Color in nature play a dominant role in creating well balanced, non disturbing and effective environment. Flowers, plants, fruits, plumage of birds, the gaudy fish, sunset, blue sky are the most striking colors of nature. Color also indicate time as much as it changes with time. Altering the day cycle and from one season to the other. Physiology shows that color has an enormous effect on the human emotional responses. Therefore color perception not only does lead to give visual striking but is also deeply involved in evoking variety of human emotions and thereby affecting human behavior. Color as a basic and vital force is lacking in architectural spaces. Now we are speaking about color balance, color harmony, color contract etc. All depend on color value, tone and brightness of the color. Most of us are not making use of its power enough. In order to strengthen the study an analysis is done on selected examples by describing reasons for the use of a particular color schemes. Examples are selected on the basis of appropriateness and the clarity and they are analyzed on the following framework. 1. Activity pattern of the space 2. User of the space 3. Mood intended to create 4. Any other higher purpose the building seeks to serve.
item: Thesis-Abstract
A Dilemma in conservation and reuse of monuments and settings: an observation of the issue with special reference to the heritage city of Galle Fort
Walgampola, L
Conservation of a monument can be carried out either as a dead or a living monument. Dead monuments are preserved and kept in a totally artificial way. Living monuments on the other hand permits its citizens to live a contemporary life style while conserving and maintaining the physical fabric of the city and environment. To minimize the extra burden of maintenance and not to create dead spaces in a city the conservationists have identified the reuse of conserved spaces and monuments. The prime aim of this is to keep the monuments in use while proclaiming its significance to society. Yet the human mutilation and the enforcement of conservation policies, regulations have failed to proclaim the heritage cities of its "living" significance and is a recurring *dilemma in conservation and reuse of monuments. It is the human participation which makes the physical context alive. For to keep a city as a living monument this dilemmatic situation has to be resolved. It is needed to facilitate the citizens to fulfill their spatial needs out of their environment. Negligence of this has caused degradation of city life in conserved cities. The study notes, the need to develop an approach that is more responsive to the living patterns. The capacity of Urban space to support dwelling that is reflected in place making is to be reinforced. Having faced this current problem of degradation of city life the heritage city of Galle -Fort is to be protected in order to facilitate it as a living monument
item: Thesis-Abstract
A dynamic load shedding scheme for maintaining system frequency stability with the increasing renewable energy penetration
(20) Herath BHMST; Widanagama Arachchige LN
Renewable energy power plants, especially grid connected solar and wind generation units are displacing the conventional generator stations with rotating machines with inertia. In Sri Lanka, renewable energy generation has begun to increase significantly. The total solar and wind energy penetration is 13% for 2020 and according to the least cost long term generation expansion plan 2018 – 2037 of Ceylon Electricity Board, this amount will be 47% by 2030. With the increased penetration of wind and solar energy generations units having no rotational inertia, there would be a variation in operational and dynamic characteristics in the power system. The power generation of solar power plants varies drastically with the cloud cover. The power output of solar and wind energy varies with their intermittent nature and as a result of it, the system frequency deviations become faster and risking the stability of power system as well. This study is focused on evaluating the frequency stability of Sri Lankan power system at major contingencies during the day-peak periods having maximum wind and solar generation. In Sri Lanka, static under frequency load shedding scheme is used to restore the stability of power system after major disturbances. This load shedding scheme is initiated based on the rate of change of frequency and under frequency settings, which shed pre-determined load amounts at frequency set points in six stages. This thesis analyzes the frequency response of Sri Lankan power system with the maximum wind and solar generation for year 2030 to evaluate the performance of the present load shedding scheme in maintaining system stability. A dynamic load shedding scheme can provide quick and optimal solution by using real-time data of operating conditions. Therefore, this research is proposing a new load shedding scheme based on dynamic load shedding method to improve the frequency stability of Sri Lankan power system while absorbing maximum solar and wind power into the system.
item: Thesis-Abstract
A Focus group study on local language computing in SMES'
Perera, MWL; Dias, G
Information and Communication Technologies (ICTs) are regarded as a powerful tool for gaining competitive advantage in any industry. Even though our population has high literacy level, many Sri Lankans are not fully-fledged computer users. Therefore the advantages of using these technologies are limited to a privileged few. Although most ICT related products and services are based on English language, the majority of the society who would benefit from these technologies is not English conversant./ This is a principal reason behind the digital divide in society where some social groups lack access to ICT. One social group that does not use computers and internet are individuals and organizations that can afford them but lack English language knowledge and also lack awareness of available local language ICTs./ The objective of this research is to find out whether the ICT penetration level in the country may be increased using local language ICT./ As the first part of the research we conducted a survey of the current state of Sinhala language computer applications in Sri Lanka. We have identified the major local language application vendors, and their products. We also obtained the views of the vendors on the issues facing the industry. In the second part of the research, we surveyed the use of local language computing by a number of small and medium-scale industries (SMEs) outside Colombo in several sectors. We also obtained their views on the obstacles to the greater use of LLC./ We then analyzed whether the lack of local language computing products is an obstacle to the greater use of ICTs in this country. Based on these surveys, we conducted a SWOT analysis and derived recommendations for strategies to be taken to improve local language computing in the country.