Faculty of Computing
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Publication Embargo Integrating industrial technologies, tools and practices to the IT curriculum: an innovative course with .NET and java platforms(acm.org, 2005-10-20) Athauda, R; Kodagoda, N; Wickramaratne, J; Sumathipala, P; Rupasinghe, L; Edirisighe, A; Gamage, A; De Silva, DExposure to state-of-art industry technologies, tools and practices by students provide CS/IT graduates highly desirable skills and marketability. A key expectation of the industry from their new cadre is a speedy integration into the business environment resulting in productive work. This usually requires having a sound technological background, a maturity to assess the environment and adapt quickly, and highly-developed soft skills to be productive in a team environment. Incorporating such experience and skills into a CS/IT curriculum is challenging and is still in its infancy stages. We undertook such as an endeavor in integrating .NET into the IT curriculum. Microsoft's .NET platform is becoming increasingly popular in the industry. Incorporating .NET into the undergraduate IT curriculum provides a plethora of skills and increases the employability of our graduates. We integrated .NET without a major revision to the existing curriculum by introducing an optional course in the final year (senior-level) of the IT undergraduate program. In addition to the .NET platform, the course covered the Java platform, which is similar in architecture to .NET. The course emulated an industry-based environment with real-world based assignments, focused on deliverables, used state-of-art IDEs and documentation, and pair programming to create a highly productive environment. The “soft skills” were integrated into the course with a project that implemented a virtual marketplace. Students in groups played different entities in the virtual marketplace and communicated with each other via Web Services. The project provided a virtual business environment and exposure to teamwork, collaboration, competition, negotiating, and creativity skills. Our first offering of the course in semester 1, 2005, attracted 128 students. The course created a highly productive environment throughout the semester. Students completed 7 assignments and the project within the 14-week semester. The initial results are encouraging and provide many insights to CS/IT departments planning to incorporate such courses.Publication Embargo Eigenface based automatic facial feature tagging(IEEE, 2008-12-12) Wijeratne, S; Jayawardena, S; Jayasooriya, S; Lokupathirage, D; Patternot, M; Kodagoda, NThere are several approaches to search databases of faces. However such methods still require a significant use of humans to interpret an eyewitness account and so forth. In many cases these searches are done using visual building tools as creating a graphical face model. A system that can easily interface with general users should directly search a person by description given verbally or textually. This would reduce costs in the search process. Facial feature characteristics identification would act as a stepping stone in cataloguing large face databases automatically thus providing the possibility of a description based face search by text. This paper presents the possibility of utilizing eigenface approach to recognize different characteristics of a facial feature and assigning descriptive words such as "Large", "Small" to each feature. After training the system, it would automatically attempt to match a pattern in the training set that best describes the input image and output a tag associated with it. This effectively allows an image of a person's face to be tagged by his or her feature characteristics. While utilizing the standard set steps as defined in the eigenface algorithm, slight modifications are done in the algorithm that matches input images with ones in the training set. The training set defined has a very huge impact for the final outcome, and due to the subjective nature of the training, future research would be done on this regard. The investigation showed that the method works fine with well defined features such as eyes but fails for features such as foreheads due to the lack of significant differences or characteristics between such features. Hence it is seen that while eigenface can be used for the categorization of well defined features, it is unable by itself to create a system that can cover all features of a face.Publication Embargo Voizlock-human voice authentication system using hidden markov model(IEEE, 2008-12-12) Maduranga, R. G; Jayamaha, M; Senadheera, M. R. R; Gamage, T. N. C; Weerasekara, K. D. P. B; Dissanayaka, G. A; Kodagoda, NSpeaker authentication is the process of automatically recognizing who is speaking on the basis of individual information included in speech waves. Many principles are used in the area of voice recognition. This paper provides a method of storing the voiceprints of individuals uniquely, based on the Hidden Markov Model. HMM has been used in the speech recognition area for a long period of time, but VoizLock project explores a way of using HMM for voice authentication which is different from speech recognition. This voiceprint will then be used for voice authentication, using text-independent speaker recognition methods in which the system does not rely on a specific text being spoken, but solely on the voice of the speaker. This paper also provides details about certain misconceptions with regard to voice authentication that exist in the society. This paper explains more about the user training phase detailing how the voice print of an individual is stored in the system by extracting certain values of the waveform using HMM. Apart from the training phase this analyses the results obtained from the testing done covering different scenarios pertaining to voice authentication.Publication Embargo Internal structure and semantic web link structure based ontology ranking(IEEE, 2008-12-12) Rajapaksha, S. K; Kodagoda, NThe semantic Web is an extension of the World Wide Web with new technologies and standards that enable interpretation and processing of data and useful information for extraction by a computer. The World Wide Web Consortium (W3C) recommends XML, XML schema, RDF, RDF schema and Web Ontology Language (OWL) as standards and tools for the implementation of the semantic Web. Ontologies work as the main component in knowledge representation for the semantic Web. It is a data model that represents a set of concepts and the relationships between those concepts within a domain. Building an ontology starting from scratch is not an easy task since it makes heavy demands on time in addition to expert knowledge related to the domain. However, we can use the existing ontologies to develop semantic Web applications. But, there are a large number of ontologies available and the ontology search engine will generate a bulk of results with different ontologies for search queries. Therefore, ranking of ontologies is needed to find the most appropriate and relevant ontologies. We consider the ranking techniques and algorithms attached to the semantic Web: (i) Swoogle Ranking (ii) Ontokhoj Ranking (iii) OntoQA Ranking (iv) AKTiveRank (v) OntoSearch Ranking (vi) content-based ontology ranking (vii) SemSearch Ranking (viii) ReConRank. Our effort considers most popularly used ranking techniques and algorithms attached to the semantic Web. We analyze the above ontology ranking techniques with algorithms and then mainly categorize into two groups. One group is based on the semantic Web link structure and the other one is based on internal structure of the ontology. We identify that some features are not addressed in ranking of ontologies selected by the above ranking techniques and algorithms. Therefore, we propose a ranking method that considers both internal structure and semantic Web link structure of ontologies to improve the ranking of ontologies. We finally evaluate the proposed ranking method. According to the results with evaluation, we allocate more weighting for internal structure and low weighting for semantic Web link structure to get the best ranking results.Publication Open Access Analysis of Risks and Bottlenecks of a Poly Bag Manufacturing Factory -A Case Study(UNIVERSITY OF MORATUWA, 2008) Gopura, R. A. R. C; Jayawardene, T. S. SThe material prices of poly bags skyrocket to new heights and forecasters see no end to this trend. Also legal restrictions are imposed on some types of polythene products. In this situation, any entrepreneur engaging in the poly bag manufacturing process faces significant challenges. Therefore, a case study of an analysis of risks and bottlenecks of a poly bag manufacturing factory was carried out for the purpose of modeling and simulation of a poly bag manufacturing factory to improve the productivity to face the underlying challenges. This paper presents the analysis methods, and the results of the analysis are also discussed.Publication Embargo A study on a poly-bag manufacturing system preliminary analysis and simulation(IEEE, 2009-12-28) Gopura, R. A. R. C; Jayawardena, T. S. SThe material prices of poly bags increase with high degree of fluctuation and forecasters see no end to this trend. Further, legal restrictions imposed on certain types of polythene products adversely affect the demand. In the light of the above, entrepreneurs of the poly bag manufacturing face many challenges. In this study, an analysis and a simulation of a poly bag manufacturing system were carried out to improve the productivity to face the underlying challenges. This paper presents analysis, modeling and simulation methods of the system. In addition, a risk prioritization method was proposed at the preliminary analysis and also a simulation tool was developed.Publication Open Access Accurate control position of belt drives under acceleration and velocity constraints(Institute of Control, Robotics and Systems, 2003) Jayawardena, T. S. S; Nakamura, M; Goto, SBelt drives provide freedom to position the motor relative to the load and this phenomenon enables reduction of the robot arm inertia. It also facilitates quick response when employed in robotics. Unfortunately, the flexible dynamics deteriorates the positioning accuracy. Therefore, there exists a trade-off between the simplicity of the control strategy to reject time varying disturbance caused by flexibility of the belt and precision in performance. Resonance of the system further leads to vibrations and poor accuracy in positioning. In this paper, accurate positioning of a belt driven mechanism using a feed-forward compensator under maximum acceleration and velocity constraints is proposed. The proposed method plans the desired trajectory and modifies it to compensate delay dynamics and vibration. Being an offline method, the proposed method could be easily and effectively adopted to the existing systems without any modification of the hardware setup. The effectiveness of the proposed method was proven by experiments carried out with an actual belt driven system. The accuracy of the simulation study based on numerical methods was also verified with the analytical solutions derived.Publication Embargo Casterless Wheelchair Robot Using Inverted Pendulum Control(IEEE, 2006-08-08) Abeygunawardhana, P. K. W; Toshiyuki, MPower assist wheelchair robot is playing a key role in the field of medical welfare robotics. But, to a certain extend, there is a setback in development due to presence of caster wheels. Hence, this paper proposes a casterless wheelchair and its control on a straight line path. That is, straight line driving of two wheel power assist wheelchair robot was proposed in this paper while keeping stability of wheelchair body itself. Balancing of wheelchair body is proposed to achieve by controlling the inverted pendulum mounted on the wheelchair. Control equations of the system are derived using Lagrange equation of motion. Two separate controllers are designed for two wheels. In addition to these two controllers, there is another controller for pendulum. Body controller is designed combining pendulum controller and wheel controller. Disturbance observer is used to cancel disturbance effects. Simulation was carried out to prove the applicability of the proposed systemPublication Embargo Vibration Suppression of Two Wheel Mobile Manipulator using Resonance Ratio Control(IEEE, 2008-12-02) Abeygunawardhana, P. K. W; Murakami, TTwo wheel mobile manipulator has the potential of becoming a multi-skilled robot in the field of robotics and it is already implemented by using inverted pendulum control. Centre of gravity position (COG) is controlled to achieve the balancing of robot. Since vibration of manipulator arms affect to the COG positions of the inverted pendulum, balancing of the robot deteriorates. Therefore, vibration control of manipulator arms of the mobile manipulator is proposed in this paper. Feedback signal for vibration suppression is introduced to null space of manipulator. Simulation and experiment was carried out to check the validity of the proposed method and the results prove the effectiveness of the proposed method.Publication Embargo Self sustaining wheelchair robot on a curved trajectory(IEEE, 2006-12-15) Abeygunawardhana, P. K. W; Toshiyuki, MToday, aged population is increasing in the world, especially in developed countries. Handicapped people could not fulfill their own task without difficulties. Therefore, medical and welfare robotics has become important. Power assist wheelchair robot has been effective in this field for many years. But, to a certain extend, there is a setback in development due to presence of caster wheels. Turning, overcoming obstacles and reversing will be easy without casters. Casterless "wheelchair and its control on a straight line was presented in author's previous paper. Two wheel wheelchair robot on curved trajectory is proposed in this paper. Balancing of "wheelchair body is proposed to achieve by controlling the inverted pendulum mounted on the wheelchair. Control equations of the system are derived using Lagrange equation of motion. Body controller is designed combining pendulum controller and wheel controller. Disturbance observer is used to cancel disturbance effects. Simulation was carried out to prove the applicability of the proposed system.