Senate Research Committee – Reports
http://dl.lib.uom.lk/handle/123/8849
2024-03-28T10:12:57ZAn Examination of alternative revenue sources in urban local governments, Sri Lanka
http://dl.lib.uom.lk/handle/123/22202
An Examination of alternative revenue sources in urban local governments, Sri Lanka
Susantha, AL; Bandusena, P
Local governments are the main grassroots unit close to the local community as it provide comfort, convenience, democratic values and accelerate economic development. Though it has the power to maintain its budget by creating new sources to perform as an independent body under the decentralized power vested by the central government, in Sri Lanka, most Local Authorities (LAs) are running on a deficit budget. Therefore, local governments are in a dilemma to provide essential services to the local community which leads to community dissatisfaction and ultimately there is a discourse of returning the power to the central government. However, due to rapid urbanization and wicked urban problems top-down governance is complex and revisiting the local opportunities and challenges have for local governance is timely. In this context, this research attempts to introduce new revenue sources for enhancing local authority revenue while examining the opportunities and challenges. A comprehensive literature review was done to identify alternative revenue sources practiced in other countries. Interviews is the main method administered in selected urban local authorities (ULA) in the Western Province. Key participants are officers of the local authorities and professionals who are working in the local governance system. The collected materials were transcribed and analyzed using a content analysis inspired by grounded theory. According to the findings, development levies, betterment fees, profit-oriented events, and income-generating projects/businesses are the potential alternative sources of revenue that can be considered in the Sri Lankan context. Further, procedural changes and capacity building enhancement for (Internal) Urban Local Authorities are essential to identify potential stakeholders and standardize the services provided.
2015-01-01T00:00:00ZEnergy efficiency improvement in cloud radio access networks (CRANs) using device centric caching policies
http://dl.lib.uom.lk/handle/123/22190
Energy efficiency improvement in cloud radio access networks (CRANs) using device centric caching policies
Samarasinghe, T; Hemachandra, K; Atapattu, S; Nuradha, T; Ranawaka, I
As the demand for wireless services is projected to double every year, wireless system designers are facing a major crisis to cater to this demand with the conventional cellular network architecture due to the scarcity of spectrum resources and high cost of energy consumption. Therefore, major architectural changes such as cloud radio access networks (CRANs) and device-to-device (D2D) communications have been proposed as potential solutions. The proposed research project is mainly focuses on improving the performance of the CRAN architecture. Firstly, we propose a spectrum selection scheme and a transmit power minimization scheme for a D2D network cross-laid with a CRAN. The D2D communications are allowed as an overlay to the CRAN as well as in the unlicensed industrial, scientific and medical radio (ISM) band. A link distance-based scheme is proposed and closed-form approximations are derived for the link distance thresholds to select the operating band of the D2D users. Furthermore, analytical expressions are derived to calculate the minimum required transmit power to achieve a guaranteed level of quality of service in each operating band. Secondly, a novel content caching strategy is proposed for a cache enabled D2D network where the user devices are allowed to communicate using millimeter wave (mmWave) D2D links (> 6 GHz) as well as conventional sub 6 GHz cellular links. The proposed content placement strategy maximizes the successful content delivery probability of a line-of-sight D2D link. Furthermore, a heuristic algorithm is proposed for efficient content delivery. The overall scheme improves the successful traffic offloading gain of the network compared to conventional cache-hit maximizing content placement and delivery strategies. Significant energy efficiency improvements can also be achieved in ultra-dense networks. Finally, we consider the physical layer security of an untrusted unmanned aerial vehicle (UAV) based D2D network, operating in full-duplex mode. A source-based jamming scheme is exploited for secure communication without utilizing any external jammers. Firstly, the optimal power allocation between the confidential signal and the jamming signal is derived to maximize the secrecy rate of each link between the source and the destination. Then, the best UAV selection scheme is proposed to maximize the overall secrecy rate of the network. The corresponding secrecy outage probability and the average secrecy rate of the network are analyzed based on the proposed UAV selection and the optimal power allocation schemes. Asymptotic results are also obtained to derive the achievable diversity order.
Following papers were published based on the results of this research project.
1. I.J. Ranawaka, K.T. Hemachandra, T. Samarasinghe, T. Nuradha, "An Energy Efficient D2D Model with Guaranteed Quality of Service for Cloud Radio Access Networks ," in Proc. International Symposium on Wireless Personal Multimedia Communications, Lisbon, Portugal, Nov., 2019. https://ieeexplore.ieee.org/document/9096086
2. T. Nuradha, T. Samarasinghe, K.T. Hemachandra, "A Novel Content Caching and Delivery Scheme for Millimeter Wave Device-to-Device Communications ," in Proc. International Symposium on Wireless Personal Multimedia Communications, Lisbon, Portugal, Nov., 2019.
https:/ /ieeexplore.ieee.org/document/9096087
2. T. Nuradha, K.T. Hemachandra, T. Samarasinghe, S. Atapattu, "Physical-Layer Security for Untrusted UAV-Assisted Full-Duplex Wireless Networks," in Proc. IEEE Global Communications Conference Workshops, Waikoloa, USA, Dec. 2019.
https:/ /ieeexplore.ieee.org/document/9024575
2018-01-01T00:00:00ZA Tool for estimating remaining life of power transformers
http://dl.lib.uom.lk/handle/123/22189
A Tool for estimating remaining life of power transformers
Samarasinghe, R; Lucas, R; Ediriweera, S; Jayarathna, P
Part 1- Modelling the Lumped Parameter Network of a Power Transformer using Sweep
Frequency Response Analysis Accurate modeling of power transformers is beneficial for fault diagnosis and the health condition assessment of the power transformers. This project proposed a novel approach of synthesizing the lumped parameter equivalent circuit of a power transformer using its frequency response by utilizing artificial neural networks and the genetic algorithms. A physically realizable transfer function derived using the sweep frequency response data of a power transformer is used to construct its lumped parameter equivalent circuit model. Then, the parameters of the model are estimated using an artificial neural network and the genetic algorithm. All parameters, objectives and constraints of the genetic algorithm and the artificial neural network are set appropriately to ensure accurate results within the shortest time span. The entire approach is validated by means of an error analysis. The proposed method is easy to implement and can be used effectively to improve the reliability of power system though accurate fault identification and health assessment of power transformers. In addition, by replacing general equivalent circuit with the proposed model, the accuracy of transient analysis results can be significantly enhanced as the high frequency behavior is simulated using lumped parameter network.
Part 2 - Fractal Characteristics of Creeping Discharges Propagating on Solid/Liquid Dielectric Interfaces A solid/liquid dielectric interface is considered a weak point in a composite insulation system, as it facilitates creeping discharges on the interface. This project proposes the use of nano-dielectrics to minimize the effect of damages which occur due to creeping discharge activity on such interfaces. A point-plane electrode arrangement-based test apparatus, energized by a high voltage supply, is used for analyzing the propagation of creeping discharges over solid/liquid interfaces using visual observation. An algorithm is used to determine the fractal dimension of creeping discharges propagating over various solid/liquid insulating interfaces. The results show that the use of nanofillers can increase the dielectric breakdown strength of epoxy by 7%.
2017-01-01T00:00:00ZDesign and development of a tactile feedback system, and its application to prosthetics and tele-operated robots
http://dl.lib.uom.lk/handle/123/22173
Design and development of a tactile feedback system, and its application to prosthetics and tele-operated robots
Chathuranga, KVDS; Lalitharatne, SWHMTD
After seeing and hearing (vision and audition), tactile sensing (feeling of touch) is the third most utilized sensation. We use our fingertips to examine properties of objects such as weight (heavy or light), shape (spherical/round or shapes with edges and corners etc.), and texture (smooth or rough). In many situations we can identify and discriminate objects by touch only. Furthermore, tactile sensing is needed for controlling the gripping force of objects and object manipulation tasks. An example would be holding an egg without dropping. We apply just enough grip force to hold the egg and careful not to crush the shell. This is possible due to the ability of the tactile sensors in the fingertips to detect micro slips occurring at the common surface of the object and the fingertips. The adjustment of its grip force is controlled by the detection of insipient slip. This tactile sensing capability is required for both tele-operated robot systems and artificial prosthetic hands that has actuated fingers for grasping and manipulation. However, limited
research has been conducted to address these issues. Researchers have tried to copy the abilities of human fingertips to robots. However, only few research has emerged with usable technologies due to the complexity of the tactile system and its information processing. Therefore, this project is conducted mainly to develop a biomimetic tactile sensing system and its control strategy for the use in prosthetic hands and a tele operated robot systems. The project proposed a tactile
sensing system and an accompanying haptic feedback systems developed using soft materials. The tactile sensors were made using magnets, hall sensors and soft overlays. The tactile arrays were used to measure tactile data while haptic feedback system made from magnets, voice coils and soft material overlays transmitted the tactile information back to the skin. The grant was successful to develop soft tactile sensor array and a soft haptic device. These devices were
utilized in a prosthetic arm to transmit tactile data to the wearer of the prosthetic arm. This tactile data was used to manipulate an object from the prosthetic hand..
Following papers were published based on the results of this research project.
I . C. Premarathna, A. Kulasekera, D. Chathuranga and T. Lalitharatne, "Development of Wearable Fingertip Tactile Display Driven by Bowden Cables," 2019 Moratuwa Engineering Research Conference (MERCon), 2019, pp. 621-626, doi: 10.1109/MERCon.2019.8818899. Link: https://ieeexplore.iece.org/abstract/document/8818899
2. C. Premarathna, A. Kulasekera, D. Chathuranga and T. Lalitharatne, "A Novel Fabrication Method for Rapid Prototyping of Soft Structures with Embedded Pneumatic Channels," 2019 Moratuwa Engineering Research Conference (MERCon), 2019, pp. 430-435, doi: 10.1109/MERCon.2019.8818891. Link: https://ieeexplore.iece.org/abstract/document/8818891
3. C. P. Premarathna, I. Ruhunage, D. S. Chathuranga and T. D. Lalitharatne, "Haptic Feedback System for an Artificial Prosthetic Hand for Object Grasping and Slip Detection: A Preliminary Study," 2018 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2018, pp. 2304-2309, doi: 10.1109/ROBI0.2018.8665044. Link:
https://ieeexplore.iece.org/abstract/document/8665044
4. C. P. Premarathna, D. S. Chathuranga and T. D. Lalitharatne, "Fabrication of a soft tactile display based on pneumatic balloon actuators and voice coils: Evaluation of force and vibration sensations," 2017 IEEE/SICE International Symposium on System Integration (SII), 2017, pp. 763-768, doi: 10.1109/SII.2017.8279314. Link:https://ieeexplore.iece.org/abstract/document/8279314
2017-01-01T00:00:00Z