PhD

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Theses and Dissertations of the Sri Lanka Institute of Information Technology (SLIIT) are licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License .

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Open Access
The Role of Social Capital and ICTs in Inter-Organizational Collaboration in a Developing Economy: An Empirical Study of the Finance Industry in Sri Lanka
(Curtin University, 2017-09) Nawinna, Dasuni Priyanwada
In the contemporary world of business, organizations cannot rely solely on their internal strengths to survive. Forming inter-organizational partnerships is becoming one of the most popular strategies available to an organization to share risks, resources and other capabilities with partners. Collaborative business strategies are especially beneficial in the emerging economies where organizations are constrained with lack of resources, technology, skills and infrastructure. Accordingly, explaining why and how some organizations do better in inter-organizational relationships (IORs) than others is a dominant challenge in the study of IORs. Social capital (SC) is an influential concept in understanding why and how some organizations do better in inter-organizational relationships. It is recognized as an important factor in developing relationships of trust, forming the foundation for greater collaboration and successful collective action. Social capital is a multi-dimensional, relational concept that turns into a powerful tool when combined with the network analysis approach and tools to study inter-organizational relationships such as alliances and joint ventures or collaborations of any form. While social capital has been found to support different firm-level value creations, such as creation of intellectual capital, resource exchange, innovation, knowledge sharing and performance, it has significance as the basis for the development of stakeholder relationships, which are essential to Corporate Social Responsibility (CSR). CSR is touted as a key enabler of both organizational performance and of sustainable development, which are also essential for developing economies. Information Systems (IS) researchers have increasingly become interested in exploring social capital in relation to Information and Communications Technologies (ICT). It is evident that social capital and ICT are mutually complementary in the interorganizational-level. While the role of social capital in the development or acceptance of ICTs and the role of ICTs in the formation of Social Capital is widely explored, the combined effect of SC and ICT on the IOR in developing contexts remains unexplored. Very little is known about the effect of ICT enabled Social Capital in the inter-bank context. The aim of this empirical research is to develop a model of how ICT-enabled social capital affects inter-bank strategic collaboration in a developing context, Sri Lanka. The purpose of this study is to investigate how the multiple dimensions of social capital influence the strategic collaboration in the Sri Lankan banking context, and the enabling role of ICTs. In order to accomplish this objective, the researcher uses quantitative techniques, the structural modelling approach combined with network measurements. Data is gathered through a survey of high-level management of banks and from public sources such as annual reports and web sites. The network analysis tools (e.g. ORA) and the statistical analysis methods (PLS-SEM) and tools (e.g. SmartPLS) have been used to derive results. The results of this study suggest that structural, relational dimensions of social capital have a positive influence towards the degree of strategic collaboration of banks. It is also evident that higher ICT capabilities at the firm-level strengthen the effect of cognitive social capital on collaboration. The results of the other moderation tests indicate that firm-size, age, gender-ratio of directors, ownership, geographic spread, culture, organization structure and previous experience strengthen the effect of social capital on strategic collaboration. The results of further analysis indicate that the structural social capital is influential for the corporate social responsibility of banking organizations. Both the inter-organizational collaboration and the corporate social responsibility yield higher financial performance at the firm-level. The study also provides evidence that the use of network measurements as the indicators of social capital provides better predictability in comparison to regular indicators. These findings provide a valuable contribution to the theory of social capital, literature on ICT for development and and network theory, contributing to a more holistic perspective that incorporates social, technical and organizational aspects and provides insights useful for building effective strategies in similar developing contexts.
Open Access
Realtime line parameter estimation using synchrophasor measurements and impact of sampling rates
(Wichita State University, 2016) Hettiarachchige-Don, A. C. S
The installation of synchrophasor measurement units within the electrical grid system have provided utilities with the ability to monitor their transmission system in real time. These real time observations allow for better situational awareness and rapid responses to adverse system conditions. However, the real time impedance of the powerline is not one of the parameters that is transmitted to the control center and therefore, has to be calculated using the data received from multiple devices. This thesis proposes a simplified methodology for this analysis that requires lower computation power in comparison to most other proposed estimation techniques. Hence, this methodology is able to produce accurate results faster and by using a smaller quantity of stored data. Due to these reasons, this methodology can be implemented to provide near real time estimation and reporting of impedance values. For the purposes of this research, only the reactance information will be calculated but a similar approach can be used to obtain resistance information as well. The methodology consists of an algorithm to calculate and estimate the reactance of a line using the reported PMU data. It includes an outlier detection and elimination algorithm as well as a denoising technique that makes use of regularized least square estimation to accurately estimate the reactance over the analysis period. The methodology proposed is tested using real synchrophasor measurement data from a utility provider. The proposed mythology can easily be adapted and applied for the estimation and calculation of other parameters using PMU data.
Open Access
Investigating the enabling role of web 2.0 technology for interactive e-learning in australian and sri lankan higher education
(RMIT University, 2015) Karunasena, A
Interactions are at the heart of e-learning as they enable learners to actively develop knowledge, acquire skills and develop the sense of belonging and satisfaction. Much attention is paid on developing interactive e-learning systems for facilitating active interactions between learners and learning resources, instructors and peer learners. Numerous technologies such as simulation technology and Web 2.0 technology are used to facilitate interactive e-learning to date. Those technologies support learners to interact with learning resources, instructors and peer learners to different extents. To facilitate interactive e-learning, it is important for educators and e-learning developers to understand how well technologies as above support interactions in e-learning. Web 2.0 technology has become popular around the world recently due to their ease of use, portability and high availability. Much research has been done on how Web 2.0 technology could be used for interactive e-learning. Existing research, however, has several limitations. For example, a majority of research has investigated how a specific Web 2.0 tool supports a specific kind of interactions in e-learning such as learner-learner interaction. Furthermore, much of existing research on Web 2.0 based interactive e-learning is conducted in developed countries. Whether Web 2.0 technology supports interactive e-learning in developing countries in a similar manner to developed countries, or whether developing countries could learn lessons from developed countries on using Web 2.0 technology for interactive e-learning are, therefore, not clear. This research aims to investigate the enabling role of Web 2.0 technology for interactive e-learning in higher education in Australia, a developed country and Sri Lanka, a developing country. To meet this aim, a quantitative research approach is adopted. Following this research approach, a conceptual framework on Web 2.0 based interactive e-learning developed based on a comprehensive review of the relevant literature, is validated using the survey data collected from learners in universities in Australia and Sri Lanka. The validation of the conceptual framework reveals that Web 2.0 technology supports the three major types of interactions in learning, namely, learner-learning resources, learner-instructor and learner-learner interactions in both Australia and Sri Lanka to a great extent. Furthermore, no significant differences are found on how Web 2.0 technology supports interactive e-learning in the above countries. The implication of these findings is that Web 2.0 tools could be used to improve the interactivity of e-learning. Another implication of this research is that new and more interactive e-learning systems can be developed by using Web 2.0 technology, in particular, for the purposes of managing learning resources, managing personal knowledge, delivering instructional support and collaborating in order to improve the effectiveness of e-learning. From a practical perspective, this study presents an in-depth investigation of how Web 2.0 technology can be used for improving the interactivity of e-learning in Australia and Sri Lanka. It also provides specific guidelines for developing interactive e-learning environments using Web 2.0 technology. From a theoretical perspective, this research finds that Web 2.0 technology could be used in developing countries and developed countries to improve the three major interactions in e-learning.
Open Access
Synthesis, characterization and applications of metal nanoparticles supported on porous carbon
(ProQuest LLC, 2017) Thambiliyagodage, C. J
Porous carbon incorporating metal nanoparticles has been synthesized by nanocasting. The main two methods of synthesis were used: the formation of nanoparticles during the carbonization of carbon, and the formation of nanoparticles by metal precursor infiltration and reduction on porous carbon. The catalytic activity of nickel nanoparticles incorporated onto hierarchically porous carbon monoliths for the reduction of p-nitrophenol was studied. p-Quinoimine was identified as the stable intermediate. Catalytic graphitization of monolithic hierarchically porous carbon by iron, cobalt and nickel nanoparticles was investigated. The catalytic graphitization of amorphous carbon increased with increasing pyrolysis temperature. Iron was capable of graphitizing carbon more effectively than cobalt and nickel, with cobalt being higher in activity than nickel. Oxygen and nitrogen rich mesoporous carbon were used to support gold nanoparticles and their catalytic activity was investigated for oxidation of benzyl alcohol in water. The catalysts showed significant catalytic activity, but loss of activity were found, resulting in decreasing conversion of benzyl alcohol on subsequent cycles.
Open Access
“AccessBIM” - A Model of Environmental Characteristics for Vision Impaired Indoor Navigation and Way Finding
(Curtin University, 2018-06) Jayakody, A
The navigation of indoor and outdoor environments play a pivotal role in the daily routine of humans. Navigation systems that provide path planning and exploration services for outdoor environments are readily available while navigation within a building is still a challenge due to limited information availability and the poor quality of GPS signals, which makes it difficult to capture characteristics within the indoor environment. Consequently, the use of GPS tracking devices for real-time map generation is not feasible. Indoor navigation is particularly difficult for people with vision impairment. According to the factsheet of the World Health Organization (WHO) as of October 2017, over 253 million people are estimated to be vision impaired: 36 million to be blind, and 217 to have poor vision. Currently, most blind and vision-impaired individuals use the white cane as an assistive tool and are often accompanied by care takers or voluntary helpers. Most modern indoor environments consist of complex architectural structures with varying arrangement of physical objects. Since retrieving indoor location information has been challenging for the vision impaired, it would be helpful if spatial information of doors, walls and staircases were made available. To address the above-mentioned problem, this thesis presents an improved schema design, an Accessible Building Information Model (AccessBIM) which could be used for generating an indoor map that could instruct vision impaired individuals in navigation, by the classification of real world objects and their locations. AccessBIM is a real-time relational database, which acts as the main component of the central system implemented to manipulate crowdsourced data such as the floor plan and architectural data along with semantic information within the built environment. The AccessBIM database stores information on the indoor arrangement of objects within buildings to facilitate the exchange and interoperability of real-time information. The database is equipped with an optimization algorithm that reduces the query execution time with the support of indexing, query re-writing, schema redesigning and a memory optimization technique introduced as “BIMcache”. vi In order to create a real-time map, the AccessBIM manipulates crowdsourced data from “smart devices” or AccessBIM users. The collection and storage of crowdsourced data, database optimization, API functions and the map construction algorithms were tested using a simulated test engine. The AccessBIM framework has the potential to play an integral role in assistive technologies related to localization and mapping, thus significantly improving the independence and quality of life for people with vision impairment whilst also decreasing the cost to the community related to support workers
Open Access
Reinforcement learning based trust framework for MANET environment
(Curtin University, 2018) Rupasinghe, L
Mobile Ad-hoc Networks (MANET) are design and implemented without the need for any infrastructure support. The properties of MANET inherently provide greater challenges in areas like security and reliability. This thesis presents three security protocols which were developed for addressing the MANET security needs. A novel trust calculation methodology and intelligent secure route prediction was designed to an existing MANET routing protocol. These protocols will help to implement a trustworthy MANET, providing a dynamic and secure environment.
Open Access
Shear capacity of composite deck slabs with concrete filled steel tubes
(University of Moratuwa, 2008) Perera, S. V. T
Steel and concrete composite systems are generally used as major structural components in multi-storey buildings. Composite construction in buildings is more popular with profiled steel sheeting (steel decking) since it serves as a working platform to support the construction loads and also as permanent formwork for concrete. To achieve large column free spans (in the range of 8m-12m), as often demanded for multi-storey office buildings, "steel and concrete composite floor trusses" may form economical solutions since they provide the facility to accommodate various service ducts within the structural zone. The concept of introducing a concrete filled steel tube (CFST), instead of the conventional open flanged steel section, as the top chord of these floor trusses has been discussed. However, the viability of this new concept should be ensured by experimental evidence on the longitudinal shear transfer capacity at the composite stage. This study discusses the experimental results of a series of push-off tests conducted on CFST embedded composite slab panels. The effect of providing different concrete top covers and effect of different concrete strengths have been investigated. With headed shear studs (two studs per sample, Configuration 3) 23%- 29% and 20%- 53% of increase in shear carrying capacity were achieved by increasing the concrete top cover from 20mm to 30mm and the concrete cube strength from grade 20 to grade 45 respectively. Composite slabs with CFSTs were 131% (only steel tube, Configuration 1) - 385% (steel tube with welded two steel strips, Configuration 2) higher than composite slabs with headed shear studs (two studs per sample). Then results of composite slabs with headed shear studs were compared with Eurocode-4 and it was at least 22% conservative. Keywords: composite slab, steel, concrete, concrete filled steel tubes, steel decking
Open Access
Trajectory Planners for Cooperative Control of Two Industrial Robots and Belt Drives
(School of Science and Engineering, Saga University, 2005-03) Jayawardena, T. S. S
This thesis focuses on trajectory planning strategies for high-speed, vibration restrained position control of belt drives and cooperative contour control of two robots in view of increasing the speed of cooperative task. The proposed solutions have been devised, implemented and verified for effective functionality. The trajectory planning in this context is carried out considering the relevant kinematic constraints met in actual practice; the maximum joint velocity constraints and the maximum joint acceleration constraints. The proposed planners are based on the principles of kinematics and the trajectory planning scenarios and, the issues are critically reviewed. For belt driven machine, a fourth order kinematic model integrating belt reaction torque is systematically derived, and thereby explained the spiky phenomenon in velocity profile of motor position, when an acceleration change is experienced. Further, a feed forward dynamic compensator is proposed to restraint vibration and to improve dynamic characteristics of the belt drives. The proposed feed forward compensator is a combination of inverse dynamics of the system and a desirable dynamic filter, which reforms the dynamic characteristics of the existing system. The planned trajectories at low speeds and high speeds are extensively tested for accurate performance with an actual belt driven machine and the results are illustrated. The proposed trajectory planners for two-robot cooperation are basically of two types. 1) Given objective cooperative trajectory exceeding the dynamic bounds of a single robot is decomposed into two concurrent complementary trajectories of two robots maneuvered simultaneously 2) For a specified objective locus, the minimum time complementary trajectories for cooperation are planned. The objective locus used to exemplify the concept of trajectory planners in both cases is an Sshaped locus and realization of the trajectories are carried out under maximum joint acceleration constraints. In the former cooperative trajectory planner, a fair task distribution is accomplished by minimizing the difference in maximum joint velocities of two robots. The complexities in planning trajectories are coped with a two-stage trajectory-planning paradigm backed with a short-listing criterion. A fourth order spline technique for position, minimizing the joint acceleration is also derived theoretically. The latter, minimum time cooperative trajectory planner, is of bang-bang type in acceleration profile and the fairness of each robot contribution is achieved through an additional contribution constraint for each robot to the cooperative task. The applicability of the trajectory-planning concept has been verified with cooperative trajectories having sharp corners. Since the proposed trajectory planners concerned under the thesis work are off-line and therefore they can be conveniently applied to existing servo systems irrespective of the computational power of in-use controller. Neither, a dramatic change in the existing hardware setup nor a considerable reconfiguration of the system is demanded in instrumentation point of view. This requirement of minimal changes in adaptation enhances the pragmatic significance of the proposed schemes.
Open Access
Lightning warning system based on slow fields and fast transient variations, suitable for oceanic tropics
(http://dl.lib.mrt.ac.lk/handle/123/1958, 2007) Abhayasinghe, N
Lightning causes a lot of property and human damage all over Sri Lanka. It has been a major requirement to develop a low cost lightning warning system. The environmental vertical static electric field changes from 0.1 kVm-1 under fair weather conditions to extreme values like 10 kVm-1 under thunderstorm conditions. Also, lightning discharges generate electromagnetic radiation from ultra low frequency (ULF) through ultra high frequency (UHF) with peak energy emission at 10 kHz. The work discussed in this thesis uses both the static field variation and the electromagnetic radiation emitted by lightning discharges to predict a thunderstorm. A portable transient detector using an envelope detector tuned to 1600 kHz is used to detect electromagnetic radiation emitted by lightning discharges. An operational amplifier circuit having a slow response with a horizontal plate antenna is used to detect the static field variation. Final decision is made by a third circuit and three levels of alarms are released accordingly. Using the transient detector only, a warning can be released 25 minutes before the close by thunderstorm with 95% level of confidence. With the entire system, the confidence of the warning further increases. The cost of the transient detector is about 2500 Sri Lankan rupees with a rechargeable battery bank. The entire system with a battery backup costs about 5000 Sri Lankan rupees. According to the observations made by the transient detector the delay between cloud flashes and ground flashes shows a distribution of the form of a fractional function with a maximm at 27.52 minutes. The newly designed lightning warning system shows an acceptable grade of performance with its low cost.
Open Access
Human gait modelling with step estimation and phase classification utilising a single thigh mounted IMU for vision impaired indoor navigation
(Curtin University, 2016) Abhayasinghe, N
This research is focused on human gait modelling for infrastructure free inertial navigation for vision impaired. A pedometer based on a single thigh mounted gyroscope, an efficient algorithm to estimate thigh flexion and extension, gait models for level walking, a model to estimate step length and a technique to detect gait phases based on a single thigh mounted Inertial Measurement Unit (IMU) were developed and confirmed higher accuracies.

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