Research Publications Authored by SLIIT Staff

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This collection includes all SLIIT staff publications presented at external conferences and published in external journals. The materials are organized by faculty to facilitate easy retrieval.

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Author: search.filters.author.Murray, I

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Now showing 1 - 10 of 26
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    PublicationOpen Access
    A Context-Aware Doorway Alignment and Depth Estimation Algorithm for Assistive Wheelchairs
    (Multidisciplinary Digital Publishing Institute (MDPI), 2025-07-17) Tennekoon, S; Wedasingha, N; Welhenge, A; Abhayasinghe, N; Murray, I
    Navigating through doorways remains a daily challenge for wheelchair users, often leading to frustration, collisions, or dependence on assistance. These challenges highlight a pressing need for intelligent doorway detection algorithm for assistive wheelchairs that go beyond traditional object detection. This study presents the algorithmic development of a lightweight, vision-based doorway detection and alignment module with contextual awareness. It integrates channel and spatial attention, semantic feature fusion, unsupervised depth estimation, and doorway alignment that offers real-time navigational guidance to the wheelchairs control system. The model achieved a mean average precision of 95.8% and a F1 score of 93%, while maintaining low computational demands suitable for future deployment on embedded systems. By eliminating the need for depth sensors and enabling contextual awareness, this study offers a robust solution to improve indoor mobility and deliver actionable feedback to support safe and independent doorway traversal for wheelchair users.
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    PublicationEmbargo
    Human Gait Modeling, Prediction and Classification for Level Walking Using Harmonic Models Derived from a Single Thigh-Mounted IMU
    (MDPI, 2022-03) Abhayasinghe, N; Murray, I
    The majority of human gait modeling is based on hip, foot or thigh acceleration. The regeneration accuracy of these modeling approaches is not very high. This paper presents a harmonic approach to modeling human gait during level walking based on gyroscopic signals for a single thighmounted Inertial Measurement Unit (IMU) and the flexion–extension derived from a single thighmounted IMU. The thigh angle can be modeled with five significant harmonics, with a regeneration accuracy of over 0.999 correlation and less than 0.5◦ RMSE per stride cycle. Comparable regeneration accuracies can be achieved with nine significant harmonics for the gyro signal. The fundamental frequency of the harmonic model can be estimated using the stride time, with an error level of 0.0479% (±0.0029%). Six commonly observed stride patterns, and harmonic models of thigh angle and gyro signal for those stride patterns, are presented in this paper. These harmonic models can be used to predict or classify the strides of walking trials, and the results are presented herein. Harmonic models may also be used for activity recognition. It has shown that human gait in level walking can be modeled with a harmonic model of thigh angle or gyro signal, using a single thigh-mounted IMU, to higher accuracies than existing techniques.
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    PublicationEmbargo
    An investigation into dynamic TLPs for smartphone communication: To facilitate timed response in way finding for vision impaired people
    (IEEE, 2013-12-11) De Silva, D. H; Murray, I
    A reliable, high speed and efficient data transfer method is a very important factor in real time Way-finding systems since it requires information with very low latency to discover paths, avoid dangerous situations, identified changes in existing maps and alternative routes. This research will develop models and methods to facilitate bounded timing with minimal latency for way-finding application for vision impaired people. As a result of analyzing the requirements for Way-finding applications, it was noted that some typical behaviours involve relatively small amount of data transfer through networks. Existing Transport Layer Protocols (TLP) are not ideal for providing such requirements. This research investigates existing TLPs and proposes modifications / extensions to facilitate demands in Way-finding applications and will implement the Dynamic TLP to incorporate both reliable data transfers with high efficiency as well as frequent data transfers which do not require reliability.
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    PublicationEmbargo
    Tempcache: A Database Optimization Algorithm for Real-Time Data Handling in Indoor Spatial Environments
    (IEEE, 2018-08-08) Jayakody, A; Murray, I; Hermann, J; Lokuliyana, S; Dunuwila, V. R
    The unstable arrangement of modern indoor environments has made navigation within buildings a difficult task. Hence, this paper introduces the AccessBIM framework, which is an efficient real-time indoor navigation system that facilitates in generating a real-time indoor map by crowdsourcing spatial data through the sensors available in mobile devices of navigators. The framework is equipped with a database optimization algorithm known as “Tempcache” which reduces the time and cost of searching data by examining the AccessBIM database for previously navigated paths, thus enabling faster data retrieval through efficient query processing. A simulation of a virtual environment similar to an actual indoor environment was used to test the algorithm. The significance of the algorithm was validated by comparing the total map generation time before and after the algorithm was applied for which the results demonstrated a reduction in map generation time with the use of the algorithm. The framework is also capable of capturing localization information with the support of i-Beacons which is then stored in a cloud server.
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    Database modelling for vision impaired indoor navigation systems
    (IEEE, 2015-08-24) Jayakody, A; Murray, I; Herrmann, J
    Cooperative research has been conducted to improve navigation services for vision impaired when they are moving through an indoor environment. Hence, to facilitate vision impaired individual in indoor environment requires a formal modelling approach for map generation and decision making about navigation pathways avoiding obstacles. The proposed data model consists "AccessBIM" database (DB) and API functions. The "AccessBIM" features such as, database connection initiation, function call, function return and database connection termination are organized as a series of function objects that meet the various needs of the database to maintain the relational schema. The proposed API primarily consists of two components, namely; DB connector and the API functions. Proposed "AccessBIM" DB will be implemented using real-time database such as "PostgreSQL". The weighted focus will be given to the areas such as Queries, Indexes and Transactions in relation to tuning the DB and the queries. The performance of the proposed API will be evaluated based on the time required to parse and Data insert rate and retrieval rates.
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    An algorithm for labeling topological maps to represent point of interest for vision impaired navigation
    (IEEE, 2015-10-13) Jayakody, A; Murray, I; Herrmann, J
    Navigation in indoor environments is highly challenging for both vision impaired and sighted people, particularly in unknown environments visited for the first time. Several solutions have been implemented and proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, each solution involves a significant deployment effort or describes objects in a manner that is unfamiliar or incomprehensible to an individual with severe blindness. This paper presents a model of adding informational point of interest to the typical indoor topological map; with particular attention to the semantic labels of the different type of indoor places and proposes a simple way to include the tags to build the topological map. Using this POI and the semantic information, the system determines the user's path, locates possible obstacles on that route, and offers navigation information to assist vision impaired navigation.
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    A database optimization model with quantitative benchmark
    (IEEE, 2016-03-11) Murray, I; Jayakody, A; Herrmann, J; Lokuliyana, S; Kandawala, D. S. A; Nanayakkara, S. E. C
    Query optimization and indexing have an immense impact on database optimization. This has been considered in many different perspectives which provide several different solutions in each case. The purpose of this paper is to primarily provide a comprehensive review and discussion of the core problems through the research on query optimization technology and indexing, based on a number of optimization techniques commonly used in the general approach of a query. A new database optimization model is designed and experiments show that this model can significantly reduce the amount of query execution time to improve the optimization efficiency. Regardless of research on the database optimization model, significant work has been done to comparatively evaluate three scenarios; non-optimized query, optimized query without following any optimization standard, and optimized query via proposed optimization model using the same experimental methodology. Further, this paper describes a benchmark that was developed specifically for the purpose of measuring the quantitative evaluations of the proposed database optimization model.
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    Enhanced algorithmic implementation to assist real-time indoor map generation for vision impaired individuals
    (IEEE, 2018-08-08) Jayakody, A; Murray, I; Hermann, J; Lokuliyana, S; Dunuwila, V. R
    The complexity of indoor environments has made navigation difficult for vision impaired individuals as well as individuals with clear vision. Although handheld mobility devices have been developed to assist the vision impaired in navigation, they are incapable of capturing parameters such as distance, angle and direction. This paper presents an appraised framework; the Accessible Building Information Model (AccessBIM), which could be used for generating an indoor map in real-time with the classification of real world objects and their locations. The AccessBIM database is equipped with two optimization algorithms; a database optimization algorithm that reduces the time of query execution through indexing, query re-writing, schema redesigning and a memory optimization algorithm known as “Memcache”. Five scenarios were tested using a simulator to determine the accuracy of the map that is generated. The use of the two algorithms ensured that the real-time map generated through the data collected from the simulation environment was similar to the actual floor plan. Hence, it can be concluded that the AccessBIM framework has the potential to play an integral role in assistive technologies related to localization and mapping, thus significantly improving the quality of life for individuals with vision impairment.
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    The construction of an indoor floor plan using a smartphone for future usage of blind indoor navigation
    (IEEE, 2014-11-27) Jayakody, A; Murray, I
    Most blind people require assistance to navigate within unfamiliar environments as there is often insufficient information about the buildings available to them. To address aspects of this problem, this paper describes the “AccessBIM” model as an approach to facility management in which a digital representation of the indoor building features is used to facilitate the exchange and interoperability of real-time information in digital format which can assist blind people to independently access unfamiliar building indoor environments. The model driven architecture that can be implemented for way finding and data synchronization, generating, in real-time topological map, to assist vision impaired individuals to navigate known and unknown indoor environment.
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    SDN based security solution for legislative email communications: Safe guarding communication
    (IEEE, 2016-04-29) Rupasinghe, L; Kulatunga, K. M. D.S. B; Murray, I; Keseva, K
    Communication plays a major role in the day to day activities of the world. Communication can be a gesture, phone call or by e-mail. This why most of the governments pay more attention to communication patterns and what people communicate with each other. In modern day information technology plays a major role in private and public sector events. It's better to be having implement security in to the major aspects of these events, like encrypted commendation channels. Software Defined Network (SDN) based encryption solution will be a advantage to the organizations so that they do not need to invest more on deploying new physical servers and implement high end encryption techniques.