https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3418 Tue, 21 Apr 2026 13:00:31 GMT 2026-04-21T13:00:31Z https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3707 Title: Opportunistic Persistent Data Storage Authors: Weerasooriya, W.A.A.C.P. Abstract: Opportunisticnetworksaretypeofmobilead-hocnetwork.Buttheyaredi erent from atypicalmobilead-hocnetwork.Becausethenodesintheopportunistic networksaremostlycomposedofhand-heldcommunicationdevicesandthosede- vices arecarriedbyhumans.Sincethenodebehaviorisdi erentfromtraditional mobile ad-hocnetworks,traditionalroutingmechanismsthatareusedinmobile ad-hocnetworkshavepoorperformancesinopportunisticnetworksandtheyarere- quired touseopportunisticpropertiesofthenetworktohavebetterperformances. Although therearelargenumberofliteraturewhichdiscussroutingstrategiesin opportunisticnetworks,itisverydi cultto ndatleastasingleworkwhichfo- cuses onpersistentsharedstoragemechanisminopportunisticnetworks.Inthis workwefocustoestablishsuchopportunisticpersistentdatastorage.Traditional distributed sharedmemoryabstractionslikeregisterscanbeusedasasolutionfor this withmodi cations.Inoursolutionwehaveusedregisterimplementationswith the quorumsystem.Duetothenatureofthenodes'mobility,traditionalquorum system introduceslongdelaysforread-writeregisteroperations.Thenecessityfor the consistencyinthequorumsystemisnotthemajorityofthenodes.Ifwecan maintainanintersectionbetweeneachread-writequorumwecaneasilyhavethe consistency inthequorumsystem.Weintroduceanovelmechanismtomaintain the intersectionbetweeneachread-writequorumwithoutperformingoperationsto the majority.Whensendingread/writemessagestheyaresenttothenodeswhich havethehigherdegreecentralityvalues.Theneventhoughwehavewrittenonly to fewernodes,thesubsequentoperationwill ndenoughintersectionswiththe currentoperation.Wehaveshowntheperformanceofournovelsolutionandit reduces thetimetakentooperationswhilemaintainingtheconsistency. Tue, 13 Sep 2016 00:00:00 GMT https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3707 2016-09-13T00:00:00Z https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3706 Title: Experience-based Personalized Diversification of Recommendations Authors: Vihanga, W.G.Dulakshi Abstract: Recommender Systems are fundamentally directed towards offering a worthwhile assistance to users, to choose something useful from an overwhelming set of options. Although accuracy of the recommendations has been regarded as the primary quality aspect of recommender systems, there’s an increasing cognizance that there are other factors such as diversity that users also value. Despite the increased interest of researchers to improve diversification of recommendations, we find that personalization of diversification has been overlooked. This work offers two main contributions. PersonalizedDiv technique which diversifies recommendation lists based on the user’s past behavior. Personalization is achieved by diversifying the recommendation list with more novel items if the user has shown diverse preferences in the past, and diversifying the recommendation list with more relevant items if the user has shown homogeneous preferences in the past. The proposed technique is capable of controlling the tradeoff between accuracy and diversity while consolidating personalization. Moreover, as obtaining a diversified recommendation list by conventional recommender systems is unlikely, current approaches generally obtain diverse results by selecting items from a larger recommendation list generated by some recommender system given a diversification technique. Thus, we find that the recommender technique used to generate the initial recommendation list is also important to the diversification procedure. Consequently, we propose ExpertRec technique which uses the ratings of users and also the ratings of experienced item category experts in recommendation generation process in order to generate a better initial recommendation list with novel and relevant items to improve the diversification process. Our experiments and evaluation provides evidence to illustrate the properties of proposed techniques and indicate the proposed approach has comparable results to state-of-art techniques. Moreover, unlike other techniques, our approach can promote both novel and relevant items and also make the diversification process personalized. Tue, 13 Sep 2016 00:00:00 GMT https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3706 2016-09-13T00:00:00Z https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3705 Title: Bimanual UI Metaphor: Towards Rehabilitation of Limited Fine Motor Skills of Di erently Abled Children N Authors: Abeywickrama, N.D. Abstract: The virtual hand metaphor is widely used in virtual reality (VR) applications for various domains. Using the latest technology, the human hand can be tracked in a free-hand, mid-air environment with a considerable accuracy. Many children has limited ne motor skills due to various causes like cerebral palsy, pediatric stroke syndromes, etc. These children have limited ability to control their ngers, which limit their interaction with the world. Virtual reality based therapeutic exercises are being used for these types of children to improve their ne motor skills. Here, the virtual hand metaphor has been used as a user interaction metaphor inside rehabilitation methods with both uni-manual and bi-manual interactions, which would help to improve ne motor skills of children. This study suggests a low-cost, free-hand VR rehabilitation environment with selected uni-manual and bi-manual interactions. This rehabilitation system is designed for general purpose desktop computers and notebook computers focusing a low-cost setup. Two proof of concepts imple- mented including bi-manual transfer and screw-nut manipulation, which are fre- quently used bi-manual interactions in rehabilitation exercises. Using a user study and a heuristic evaluation, the virtual hand metaphor and the implemented proof of concepts are being evaluated in both medical and computer science aspects. The results shows that it is e ective than regular exercise methods, but need improvements in nger-speci c interactions and eye-hand co-ordination in order to achieve considerable improvement of ne motor skills. The evaluator's ques- tionnaire show that it is usable for only cognitive child patients who are able to understand and use a computer environment. In theoretical aspect, the virtual hand metaphor has achieved signi cant usability aspects as a UI metaphor. Inability to give sensory feedback is one of the main limitation of this study which is one of the focusing aspects in ne motor rehabilitation. Tue, 13 Sep 2016 00:00:00 GMT https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3705 2016-09-13T00:00:00Z https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3704 Title: With the widespread adoption of Internet of Things (IoT), it is estimated to become the largest device market in the world more than double the size of smart phones, PC, tablet markets combined. More and more organizations, consumers, businesses and governments are recognizing the bene ts of a connected environment of devices. This also introduce a fundamental dilemma. The data amassed from these devices will equate to an unprecedented volume. This problem propagates when data intelligence is needed, that require the collected data to be transported to a computation source, usually through a network connected to the internet. As current and forthcoming network infrastructure falls short handling this high velocity of data, the need for a robust computation model that processes data at the generated source becomes apparent. We aim to ful ll this void by proposing a novel architecture that is designed based on the Fog computation model. By leveraging the capabilities like reduced latency and data tra c inherent to the Fog computing platform, our architecture thrive to provide enhanced performance to applications that have demanding real time computation needs. Complex event processing is at the core of our computation model, simulating the environment changes captured through sensors in the form of events. Uniqueness of our architecture lies in its Fog to Cloud gateway design, which enable the computation model to take advantage of Cloud computing's resource pools. To resolve the scheduling of events to the Cloud or to the Fog node, we used a novel approach where a rule engine determines the computation source according to the resources of Fog node. To aid the rule engine, we formulated an event dependency resolving mechanism based on event trees. Also an extension of our rule engine concept is presented that predicts the resource values of the Fog node, which can be used schedule events anticipating a future system state. We explore a thorough evaluation and validation process that gauge the e ectiveness, performance and the accuracy of our novel architecture's implementation and its components. System comparison was done with a traditional complex event processing engine that has Cloud as the computation source. In our comprehensive evaluation process, results obtained con rm the implemented systems superior e ectiveness and performance in real time applications. Our study validates the need of the proposed hybrid computation model that makes use of both Fog computing and Cloud computing platforms in cases of applications with real time reaction needs. Authors: Madumal, M.B.A. Prashan Abstract: With the widespread adoption of Internet of Things (IoT), it is estimated to become the largest device market in the world more than double the size of smart phones, PC, tablet markets combined. More and more organizations, consumers, businesses and governments are recognizing the bene ts of a connected environment of devices. This also introduce a fundamental dilemma. The data amassed from these devices will equate to an unprecedented volume. This problem propagates when data intelligence is needed, that require the collected data to be transported to a computation source, usually through a network connected to the internet. As current and forthcoming network infrastructure falls short handling this high velocity of data, the need for a robust computation model that processes data at the generated source becomes apparent. We aim to ful ll this void by proposing a novel architecture that is designed based on the Fog computation model. By leveraging the capabilities like reduced latency and data tra c inherent to the Fog computing platform, our architecture thrive to provide enhanced performance to applications that have demanding real time computation needs. Complex event processing is at the core of our computation model, simulating the environment changes captured through sensors in the form of events. Uniqueness of our architecture lies in its Fog to Cloud gateway design, which enable the computation model to take advantage of Cloud computing's resource pools. To resolve the scheduling of events to the Cloud or to the Fog node, we used a novel approach where a rule engine determines the computation source according to the resources of Fog node. To aid the rule engine, we formulated an event dependency resolving mechanism based on event trees. Also an extension of our rule engine concept is presented that predicts the resource values of the Fog node, which can be used schedule events anticipating a future system state. We explore a thorough evaluation and validation process that gauge the e ectiveness, performance and the accuracy of our novel architecture's implementation and its components. System comparison was done with a traditional complex event processing engine that has Cloud as the computation source. In our comprehensive evaluation process, results obtained con rm the implemented systems superior e ectiveness and performance in real time applications. Our study validates the need of the proposed hybrid computation model that makes use of both Fog computing and Cloud computing platforms in cases of applications with real time reaction needs. Tue, 13 Sep 2016 00:00:00 GMT https://dl.ucsc.cmb.ac.lk/jspui/handle/123456789/3704 2016-09-13T00:00:00Z