Research Papers - Department of Electrical and Electronic Engineering

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Author: search.filters.author.Kulasekere, E. C

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Now showing 1 - 10 of 24
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    PublicationOpen Access
    Dempster–Shafer information filtering framework: Temporal and spatio-temporal evidence filtering
    (IEEE, 2015-06-04) Weeraddana, D. M; Kulasekere, E. C; Walgama, K. S
    This paper presents an information processing framework for distributed sensor networks. The framework is capable of directly processing temporally and spatially distributed multimodality sensor data to extract information buried in the noise clutter. Moreover, we introduce distributed algorithms to implement spatio-temporal filtering applications in grid sensor networks within the context of the framework. The proposed framework is based on the belief notions in Dempster-Shafer (DS) evidence theory and evidence filtering method. Further analysis is done by exploiting a fire propagation scenario when high noise is present in the sensed data. We compare intuitively appealing results against DS fusion method to grant further credence to the proposed framework.
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    PublicationEmbargo
    Free route air traffic flow manager
    (IEEE, 2005-12-11) Abeysooriya, M; Kulasekere, E. C
    As the world moves towards the era of globalization and as the business world continues to revolutionize, meeting the expectations of a timely and safe air transportation system has become major challenge to the field of aviation. Most of the existing air traffic control systems primarily focus on generating pre-defined routes for aircrafts based on the 'fixed route model'. But with the advancement of technologies in the field of aviation an effective and practical mechanism called 'free route modeling' has been introduced. The few test beds that exist worldwide based on this concept, have been implemented for certain specific airspaces eliminating the possibility of using this strategy at any location worldwide. This paper presents the design and implementation of the 'free route air traffic flow manager' project which proposes a framework which can be used as a generic tool to over come this limitation. This tool will allow the user to dynamically create a free route modeling system for a certain airspace by configuring a 3D airspace according to the given requirements for that airspace. The dynamically developed free route modeling system will facilitate the functionalities of generating the initial free route for an aircraft & provide dynamic re- planning for the configured air space when a conflicting scenario is reported.
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    Distributed Wireless CSMA/CA based Unified Navigation Solution
    (IEEE, 2006-12-15) Samarakoon, S. M. D. D; Silva, A. P. M; Samaraweera, S. M. D. W; Fernando, T. G. A; Kulasekere, E. C
    This research proposes a multiple access protocol known as the Distributed Wireless CSMA/CA (DWCC). This protocol is optimized for a distributed wireless communication network where the node availability and behavior are both uncertain and unpredictable. An application based on a distributed communication network formed using inter vessels communication at deep sea is used to illustrate the salient features of the proposed protocol. A method is outlined on how the proposed new protocol can be applied to extend radar vision at each vessel in the presence of radar jamming and/or communication node failure at mid sea. That is, the DWCC protocol is used to gather information from all vessels to construct a cumulative radar map at any node and thus extending the radar vision beyond the display capability of a single node.
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    PublicationEmbargo
    Role of the Context in Intuitive Combination of Evidence
    (IEEE, 2008-12-12) Senaratne, D; Kulasekere, E. C
    Combination' in `Theory of Evidence' is merging evidence received from different sources to reduce the uncertainty one entertains regarding the problem in concern. Rules having different semantics and producing conflicting outputs are found in literature. Unfortunately proper guidelines are not available to select the combination rules suitable for a given problem. It has resulted in counter-intuitive use of the rules. Contextual information governs how the frames against which the evidence is expressed are related. It is however not embedded in the evidence and therefore not available to the agent applying the combination rule. This paper explores how contextual information can be extracted to be used for improving the intuitiveness of combination. It establishes a systematic way to extract contextual information, based on what the authors denote as hypothesis-level and frame-level inter-frame relationships.
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    PublicationOpen Access
    IMAGE PROCESSING BASED GIRTH MONITORING AND RECORDING SYSTEM FOR RUBBER PLANTATIONS
    (Academy & Industry Research Collaboration Center (AIRCC), 2015-02-01) Thilakarathne, C; Bhanusri, P; Randeny, T; Rupasinghe, H; Kulasekere, E. C
    Measuring the girth and continuous monitoring of the increase in girth is one of the most important processes in rubber plantations since identification of girth deficiencies would enable planters to take corrective actions to ensure a good yield from the plantation. This research paper presents an image processing based girth measurement & recording system that can replace existing manual process in an efficient and economical manner. The system uses a digital image of the tree which uses the current number drawn on the tree to identify the tree number & its width. The image is threshold first & then filtered out using several filtering criterion to identify possible candidates for numbers. Identified blobs are then fed to the Tesseract OCR for number recognition. Threshold image is then filtered again with different criterion to segment out the black strip drawn on the tree which is then used to calculate the width of the tree using calibration parameters. Once the tree number is identified & width is calculated the girth the measured girth of the tree is stored in the data base under the identified tree number. The results obtained from the system indicated significant improvement in efficiency & economy for main plantations. As future developments we are proposing a standard commercial system for girth measurement using standardized 2D Bar Codes as tree identifiers
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    PublicationOpen Access
    Robustness of digital filters with respect to limit-cycle behavior under coefficient perturbations
    (International Society for Optics and Photonics, 1996-06-07) Kulasekere, E. C; Premaratne, K; Bauer, P. H
    A digital filter which has been designed to be limit cycle free may exhibit limit cycles at the implementation stage. This is due to the inability to implement filter coefficients exactly in hardware when they are quantized to satisfy available wordlength requirements. Given a digital filter which is limit cycle free under zero input conditions, the work below presents an algorithm which finds a region in the coefficient space, about the nominal filter coefficient values, where in the filter remains limit cycle free. Furthermore the results of the algorithm will also indicate the availability of other machine representable numbers for the coefficients that fall within this robustness region. Hence one may even choose shorter wordlength registers for coefficient storage if the corresponding grid falls within the constructed robustness region.
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    PublicationEmbargo
    Enhancing flexibility of belief representations
    (IEEE, 2008-04-06) Senaratne, D; Kulasekere, E. C
    Several attempts have been made to enhance the flexibility of belief representation in the Shafer model. This paper questions their ability to retain the intuitiveness. A method of enhancing the flexibility of belief representations, without compromising the intuitiveness is proposed. In it we relax the Shafer's exclusivity constraint by disregarding the formalism: 'subsets as propositions' and expressing support as functions of propositions. A compact and intuitive notation for propositions, termed N-of, is introduced. This notation simplifies the formulation of propositions from the statements humans make.
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    An analytical framework for cluster distribution of EDCR class of algorithms in Wireless Sensor Networks
    (IEEE, 2009-12-28) Gamwarige, S; Kulasekere, E. C
    Energy Driven Cluster-Head Rotation (EDCR) class of algorithms are energy aware distributed clustering techniques for effective ad hoc deployed Wireless Sensor Network (WSN) organization. The application of this class of algorithms requires the setting of salient parameters at the design stage of the WSN to achieve desired results. Two such parameters which should be known in advance are the cluster density and the distance between neighbouring cluster heads (CHs). In this research we analyze the effect of algorithm design based on these two parameters. Simulation techniques are given to support and verify the analytical results.
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    Blended induction program for electronic engineering freshmen
    (Sage Publications, 2018-10) Dayawansa, I; Wijenayake, C; Edussooriya, C; Samarasekara, T; Karunasekara, C; Dias, D; Samarasinghe, K; Kulasekere, E. C; Rodrigo, R; Dayananda, N
    This paper presents learning and teaching experiences gathered from an induction program conducted at the Department of Electronic and Telecommunication Engineering, University of Moratuwa, Sri Lanka for newly enrolled undergraduate students. The induction program, named as the pre-academic term, was an experimental effort to explore the applicability of blended leaning concepts to enhance the learning experience of Engineering freshmen, while enabling smooth transition from high school to university education. In addition to standard lectures, an integral part of the program was in-class demonstrations, where electronic circuits were assembled from scratch on a printed circuit board and demonstrated using a projected camera during the lectures. Organization, learning objectives, brief description of the example projects are presented along with a summary of formal student feedback. More than 85% of the freshmen indicated that the induction program helped them to smoothly begin the university education. A qualitative assessment in the laboratory work indicated that about 98% of the students successfully completed the assigned hands-on activities.
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    PublicationOpen Access
    Cluster density of dependent thinning distributed clustering class of algorithms in ad hoc deployed wireless networks
    (Hindawi, 2012-01-01) Gamwarige, S; Kulasekere, E. C
    Distributed clustering is widely used in ad hoc deployed wireless networks. Distributed clustering algorithms like DMAC, HEED, MEDIC, ANTCLUST-based, and EDCR produce well-distributed Cluster Heads (CHs) using dependent thinning techniques where a node’s decision to be a CH depends on the decision of its neighbors. An analytical technique to determine the cluster density of this class of algorithms is proposed. This information is required to set the algorithm parameters before a wireless network is deployed. Simulation results are presented in order to verify the analytical findings.