Volume 04 - 2008
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/13901
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Item Detecting and preventing plagiarism in online assessment(University of Kelaniya, 2008) Wannige, C.T.; Sonnadara, D.U.J.; Usoof, H.A.; Hewagamage, K.P.Assessment is an important area in both teaching and learning. E-assessment is the foremost methodology for assessment in distance learning. This paper presents a method based on client-server architecture that can be used in capturing/preventing plagiarism in online assessments for distance learning centres. Among many possible scenarios of plagiarism, developed system focused on preventing or capturing unauthorised help obtained from online chat forms, websites or other types of communication mediums as well as use of stored text/restricted software. Bench tests show high degree of accuracy in capturing plagiarism scenarios by monitoring the change of grey values observed in edge detected screen shots. During pilot tests, participants attempted activities of plagiarism although the software was designed to prevent the act of plagiarism. The results show 97% accuracy in capturing plagiarism scenarios by the developed software in a restricted Ubuntu Linux environment.Item Mathematical structures in pattern organizations(University of Kelaniya, 2008) Kodituwakku, S.R.Since the introduction of design patterns, a large number of patterns have been identified and documented. As a result, patterns in the literature relate one another in different ways. Unfortunately, most of these patterns are not properly organized. In applying these patterns in to problems at hand novice designers encounter many difficulties such as identification and selection of collectively applicable set of patterns that suits the problem at hand. We investigate mathematical structures in existing pattern organization techniques such as pattern catalogues, pattern systems and pattern languages. Then we attempted to use these mathematical structures in developing a new organization technique. This paper proposes a new organization method and illustrates it with a collection of object oriented patterns drawn from the literature. Our investigation indicated that existing pattern organizations form graph structures and categorical structures. These structures are formed by patterns and relationships among them. The proposed organization method organizes patterns into sequences according to the relationships among patterns. This organization consists of two types of categories: major category and alternative category. The major categories are defined based on the Uses relationship and the alternative categories are defined based on the Variants, Refines and Conflicts relationships. Each major category consists of patterns that have potential to form a pattern system or a pattern language. So they assist practitioners in finding a sequence of related patterns that can be collectively applied to solve complex problems. Each alternative category consists of patterns that provide alternative solutions to the same problem or similar problems. It assists in finding a number of possible solutions (patterns) to a particular problem. The proposed organization combines these two types of categories by structuring them into pattern sequences. A pattern sequence consists of a major category and a collection of related alternative categories. Pattern sequences assist practitioners in finding a collectively applicable patterns and possible alternatives to them. So pattern sequences facilitate the selection of most appropriate sequences of patterns to solve complex problems without searching through the pattern literature.Item Sago as a medium for “in vitro” culture of some common soil bacteria(University of Kelaniya, 2008) Kapilan, R.; Thavaranjit, A.C.Nutrient agar (NA) medium is universally used as a general purpose medium for the culture of a broad range of bacteria and the cost of this commercially available medium is considerably high. Sago (Metraxylon sagu) contains a considerable amount of starch and a small amount of reducing sugars and is not used as a staple food in Sri Lanka. This study was aimed to find out the suitable composition of the sago medium compared with NA and to carry out growth studies of soil bacteria on sago medium. Media were prepared in different compositions by addition of different amount of sago in 100mL volume (25mL of distilled water + 75mL of young king coconut sap) separately. Bacterial suspensions (5.21×106 cfu/ml, SD=1.12) of Bacillus, Pseudomonas, Klebsiella, Enterobacter, Serratia and Staphylococcus were transferred on the selected sago medium separately by using spread plate techniques. There was no significant difference between sago and NA media in number of the colonies (t test; p = 0.05). Colonies appeared earlier in NA media than in sago media. But the colony morphological characters such as shape/form, margin, elevation, colour and size were almost similar to all bacteria selected on both media, except consistency. Thus, instead of NA the low cost and easily available sago medium could be recommended for the cultivation of soil bacteria.Item Applied magnetic field and stress induced anisotropy dependence of energy for oriented ferromagnetic thick films(University of Kelaniya, 2008) Samarasekara, P.The energy of perfectly oriented thick ferromagnetic films at different applied magnetic field and stress was studied using classical model of Heisenberg Hamiltonian. For the values of parameters used in this report, the energy required to orient the film with 1000 layers in 41.4° or 57.6° directions becomes minimum at applied magnetic fields of ω Hout = 4.8 or ω Hin = 4.8, respectively. The film can be easily oriented in 172° direction by applying the external stress ω Ks = 3.6 perpendicular to the film plane, for the values of parameters used in this report. These final results mainly depend on the values of other parameters used for calculations. The energy becomes minimum and maximum at almost the same values of oriented angle (θ), in plane magnetic field, out of plane magnetic field and stress for both sc(001) and bcc(001 lattice types. But the values of energies corresponding to maxima and minima are slightly different for the sc(001) and bcc(001) lattices.Item Service Technologies Creates a Tangible Link for Value Generation: Service Economy in Sri Lanka(University of Kelaniya, 2008) Ekanayake, S.; Abeysinghe, D.A country’s ability to develop a competitive service economy depends on its production sector, as they demand use of services. Continuous improvement or innovation in technologies in both manufacturing and services will simultaneously increase smooth flow of operations for competitiveness by lowering cost of production to enhance customer satisfaction, to attain value. The success of different industries depends on how well the service sector is geared to support them. To carry out better management strategies for value gain, it is necessary to provide a tangible link to integrate the production and distribution channels for efficiency and effectiveness of the organizational and technological dimensions. Technology transfer and continuous innovation of systems enhances productivity growth for cost competitiveness leading to better prices, responsiveness and flexibility of the processes to deliver a quality product to changing markets. The research purpose is therefore to identify management strategies and service technologies to analyze the characteristics of research variables in relation to GDP value generating sectors and focus on issues relating to value.Item Physical Interpretation of Anomalous Absorption of Partial Waves by Nuclear Optical Potential,(University of Kelaniya, 2008) Piyadasa, R.A.D.; Munasinghe, J.; Karunatileke, N.G.J.Anomalous absorption of light ion partial waves by the nuclear optical potential is an interesting phenomenon showing striking systematic in various parameter planes. However, the theoretical description of this phenomenon is extremely difficult. In this contribution, we address the problem of its physical interpretation. It is shown that the zero of the S-matrix element associated with the anomalous absorption of a partial wave is due to the destructive interference of the reflected waves, from the innermost turning point and the outermost turning point, in the asymptotic region when WKB approximation is feasible.Item Determination of Phase Transitions in Y-Shaped, Branched Alkane, C120H241CH(C195H391)C119H23 Using Raman Spectroscopy(University of Kelaniya, 2008) Suranga, P.A.; Wickramarachchi, R.; Spells, S.J.Raman spectroscopy has been used to identify solid – solid phase transitions in the symmetrically branched alkane, C120H241CH(C195H391)C119H239 during real-time heating. The vibrational modes in the region from 1700 to 200 cm-1 were studied. A single phase transition was identified at 87°C ± 5°C in this alkane based on the changes in the band intensities. It was revealed that the crystalline bands show subtle changes whereas the disorder bands show the most significant changes at this transition.Item Exact Formula for the Sum of the Squares of the Bessel Function and the Neumann Function of the Same Order of Half-Odd Integer(University of Kelaniya, 2008) Piyadasa, R.A.D.; Mallawa Arachchi, D.K.Sum of the squares of the Bessel function and the Neumann function of the same order of half-odd integer has been found to be very useful in addressing a puzzle in nuclear physics. One approximate formula available in the literature is valid for the complex argument whose real part is greater than zero, and the absolute value of error term is undefined for half-odd integers. Another approximate formula which is valid for all complex arguments has been obtained using sophisticated mathematical method called Barnes' method. However, the error in the formula is very difficult to calculate. We have obtained exact formula for the sum of the squares of Bessel and Neumann functions of the same order of half-odd integers which is valid for all complex arguments, and its proof is also given.Item Should shrimp culture be blamed? The interactions of diverse natural resources utilization in shrimp culture(University of Kelaniya, Sri Lanka, 2008) Wijeyaratne, M.J.S.; Epa, U.P.K.Due to high demand and high price received for the produce and also due to capture fishery can no longer meet the demand, the shrimp culture industry is rapidly growing, especially in coastal belt of Asia where most of the environmental factors are conducive. In recent years, number of problems associated with the expansion of the industry has been identified. Therefore, the shrimp culture is considered to be environmentally damaging and unfriendly and as such it has been the target of criticism by environmental conservation lobby groups. As a result of such criticism the general public is of the impression that the shrimp farming is dangerous to the environment and to the economic development of a country. This paper explores the popular negative image of shrimp pond culture, focusing on the diverse natural resources utilization by the industry in tropical coastal areas.