https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/1649 2026-04-28T07:25:42Z https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/1689 Title: Geo-Ontology Based Personalized Information Retrieval Authors: Dilrukshi, I.K.D. Abstract: The information era created new opportunities as well as challenges for information retrieval. The vast information ocean is growing exponentially and geographical infor- mation holds big portion of it. Thus the geographical reference terms appear in many user queries. The geographical information is highly ambiguous. However the con- ventional search engines don0t bother about the ambiguities and the semantic nature of those geographical reference terms. This causes low precision in search results in geographical information retrieval. Semantic web services and geo-ontology provides a new method and technology for sharing and resolving the ambiguities in geographical information. Through Geo- ontology Based Personalized Information Retrieval I have investigated on the geo- ontology concept for resolving the ambiguities in geographical information and the query expansion mechanism for e cient geographical information retrieval. The experimental results shows that the ability of removing the ambiguities in user queries and the automatic query expansion in geo-ontology based information retrieval causes to higher precision of searching results against the keyword based searching algorithm. 2013-12-18T00:00:00Z https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/1687 Title: Telepresence Over Mobile Phones Authors: Deshan, S.B.M.C. Abstract: Telepresence is a use of virtual reality technology, especially for remote control of machinery or for apparent participation in distant events. And telepresence systems are used to establish a sense of presence or shared space among geographically separated members of a group. Due to the popularity of telepresence, a huge amount of research has been devoted towards the development of novel telepresence frameworks. Most of these systems are standalone non portable systems where supports only for communications and do not consider on supporting multiuser collaborative works with telepresence. We present a telepresence framework for mobile phones with multiuser participation of collaborative work and we have implemented robots based structure to represent the distant event which all the participants work together to accomplish a single goal. Before the wider acceptance of telepresence the famous technique for participate with distant operation was teleoperation. The teleoperation is the process of human operator controls a robot from a distance. The connotation of teleoperation is that the distance is too greater for the operator to see what the robot is doing. In most cases, the human operator sits at a workstation and directs a robot through some sort of interface. After introducing of virtual reality technologies the teleoperation was drastically changed to telepresence which is a greater approach for projection of the human sensory apparatus into a remote location. Later developments of telepresence frameworks much focused on reducing cognitive fatigues exist with most of the virtual reality approaches and making the interface more natural. Some of the identi ed cognitive fatigues are attention wanders, experience headache and other physical symptoms of stress due to limited eld of view and jerky images. The simulator sickness is also an important factor to consider which cause due to discordance between the visual system saying operator is moving and inner sensors saying the operator is stationary. We came up with a mobile telepresence framework which improves ordinary telepresence frameworks to use in mobile phones and facilitates participants to collaborate in a distant operation. The factors what we have focused on for improving with our framework are portability of telepresence, enhancing the accuracy of users decision making with multidirectional vision and using of multi-modal interfaces available on mobile phones to update the user with di erent sensory feedback information. The implementation of the framework was distributed into three di erent platforms as Mobile platform, Desktop and Robot hardware/embedded platform. 2013-12-18T00:00:00Z https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/1688 Title: Passive Tracking for Mobile Augmented Reality Using Landmark Identification Authors: Dharmawardhana, S.R. Abstract: Augmented Reality is to integrate artificial elements such as sound, graphics, images, video and tactile feedback into a user s real world environment in order to improve the user s perception of the reality. Nowadays sophisticated mobile devices that consist of 3D rendering capabilities and various kinds of sensors built into them have become part of our lives. With this growing complexity and performance of mobile devices and their wide usage and popularity, the augmented reality has shifted towards mobile computing. When considering tracking and registration in a mobile augmented reality system, as virtual objects are placed in the field of view of the user; the tracking should be done in real time with low latency. The jitter should also be low enough so that user may not see augmented objects changing their position with user s movements. Most vital is the techniques used need to be computationally less complex to process in mobile platforms. In order to augment computer generated graphics objects seamlessly into the real world images, an accurate computation of the user s pose with respect to the virtual world is required. The existing tracking methods such as GPS, small sensor based methods, and image based and vision based methods currently in existence has some limitations. High cost of sensor based methods, requirement of artificial feducials in image based methods are some of these limitations. In order to counter some of these limitations, we propose a landmark based tracking technique. The proposed method does not use any artificial markers. It uses set of images of the planer surfaces in the environment to determine the pose. Experimental results show that this tracking method is accurate, has low jitter and can perform at 10 Hz speed. 2013-12-18T00:00:00Z https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/1679 Title: Dynamically Discovering Mathematical Web Services Authors: Suriyaarachchi, H.T. Abstract: Dynamic Discovery of Web service based on existing service descriptions is the main problem of the Web service discovery. Selecting Web services with respect to user preferences is another problem. This thesis addresses the problem of selecting user-preferred service for dynamic discovery of mathematical Web services. i.e. Web services that describe mathematics-related operations. The solution is based on semantic web technologies. We have proposed an algorithm which is optimized to select Web services based on user preferences. 2013-12-18T00:00:00Z