Volume 04 - 2008
http://repository.kln.ac.lk/handle/123456789/13901
2024-03-28T10:48:16ZDetecting and preventing plagiarism in online assessment
http://repository.kln.ac.lk/handle/123456789/9957
Detecting and preventing plagiarism in online assessment
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.
2008-01-01T00:00:00ZMathematical structures in pattern organizations
http://repository.kln.ac.lk/handle/123456789/9956
Mathematical structures in pattern organizations
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.
2008-01-01T00:00:00ZSago as a medium for “in vitro” culture of some common soil bacteria
http://repository.kln.ac.lk/handle/123456789/9955
Sago as a medium for “in vitro” culture of some common soil bacteria
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.
2008-01-01T00:00:00ZApplied magnetic field and stress induced anisotropy dependence of energy for oriented ferromagnetic thick films
http://repository.kln.ac.lk/handle/123456789/9954
Applied magnetic field and stress induced anisotropy dependence of energy for oriented ferromagnetic thick films
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.
2008-01-01T00:00:00Z