Browsing by Author "Gamage, CD"

Now showing 1 - 17 of 17

item: Conference-Abstract
Case Study of WSN as a replacement for SCADA
(2009) Amarawardhana, C; Dayananada, KS; Porawagama, H; Gamage, CD
The increasing interconnectivity of SCADA (Supervisory Control and Data Acquisition) networks has exposed them to a wide range of network security problems. Also in that case WSN (Wireless Sensor Networks, which is a new computing paradigm that emerged from the fusion of the SCADA systems and Ad hoc networks technologies, have gained the advantage over SCADA due to its simplicity and the ad-hoc nature of the network. This paper provides an overview of all the issues that are involved in strengthening the interconnectivity of SCADA networks and how the WSN has gained the advantage as a solution for SCADA. The paper describes the general architecture of WSN and SCADA networks and the properties of some of the commonly used SCADA communication protocols. This paper presents an overview of challenges in the design and implementation of WSNs. It summarizes the potential challenges that influence the WSNs design. Also this paper proposes an example solution to interconnect such environments using low cost and customizable sensor nodes which each has the computational power built in.
item: Conference-Abstract
A Cell biology inspired model for managing packet broadcasts in mobile ad-hoc networksc
Sooriyaarachchi, SJ; Gamage, CD
The modern computing paradigm is moving towards personal devices that incorporate wireless networking, mobility, and collaborative applications. The networking paradigm that best matches this scenario is the mobile ad-hoc network (MANET). A common instance of a MANET is the dense MANET that can be expected in any setting where large number of people congregate such as movie theatres, sports stadiums, shopping malls, transportation hubs, lobby of public offices, lecture rooms, etc. The existing packet transmission protocols for MANETs are inefficient for dense MANETs due to packet broadcast storms for stateless protocols and non-availability of anchor nodes for stateful protocols. This paper presents a new packet broadcast model developed based on cell biology and provides simulation results on protocol efficiency. As Smartphone devices and collaborative applications proliferate among users, the proposed dense MANET protocol could provide real benefits to Internet enabled users and devices.
item: Conference-Abstract
Chaos theory based cryptography in digital image distribution : visibility controlled image encryption scheme (ViCIEn)
Ranmuthugala, MHP; Gamage, CD
The amount of visual information available in digital format has grown exponentially in recent years due to the wide availability of digital equipments, changes in the way people socially interact by setting up community web pages, wide spread use of the Internet in all types of personal and business activities, pay-after-trial services of digital multimedia and developments in high speed transmission of digital images with high reliability. However, the wide accessibility of the Internet and its connected hosts and availability of technology to capture network traffic or penetrate hosts have made digital images vulnerable to unauthorized access while in storage and during transmission over a network. Hence users of the Internet and application that use or process digital images need to address security issues to protect commercial value of images and also ensure user privacy and other issues. The objective of the research presented in this paper focused on proposing an image encryption technique which is capable of encrypting an image effectively and securely with a predefined visibility level. The stipulated objective is achieved by employing 2D chaotic map called the Kaplan-Yorke map.
item: Thesis-Abstract
An E-health records system for indigenous medicine practice in Sri Lanka
Abewardana, SMNR; Gamage, CD
This research study is based on the indigenous medicine practice in Sri Lanka. This system of medicine still uses traditional methods for treatments and has a long historical background with conventional development also taking place. As of late 2011, there are 62 Ayurveda hospitals, 208 Dispensaries, and 231 Free Ayurveda dispensaries for indigenous healthcare delivery. These 501 Ayurveda healthcare delivery centers are functioning under the government sector. With the ongoing recognition of immense benefits in indigenous medicine and treatments, a local as well as a global demand for the indigenous system ofmedicine is increasing rapidly. The current means of indigenous healthcare delivery and management has been unable to meet this growing demand in an effective manner. In addition, there has been no concentrated effort to adopt modem technological practices to cope with that demand for indigenous medicine and treatments. The main objective of the research work presented in this thesis was to explore the approaches and mechanisms required for introducing an e-health records system to the indigenous medical practice and consequent implications to practitioners and the field of indigenous medicine. The generally identified problems hindering the adoption of modem technological capabilities in indigenous medicine practice were the use of informal medical record systems that are paper-based and the nonavailability of standard lists of Classification of Diseases, Medicinal Plants, and Prepared Drugs. This research study focused on the means necessary to overcome these main problems and to identify the perception of Ayurveda medical officers towards the use ofICT and their tendency to adopt modem practices. This thesis also analyzes the experiences ofseveral other countries in the adoption of ICT in healthcare sector thrdugh a detailed literature review. Based on the literature study, a theoretical model to study adoption of ICT technologies and mechanisms was selected and modified according to the local requirements. Using this model, termed the Fit Individual Task and Technology (FITT) model, an empirical research study was conducted through a questionnaire-based data collection. The theoretical vn model allows the study of three variables, Attitudes Towards Use of ICT (ATUI), Perceived Usefulness (PU), and Perceived Ease of Use (PEU) to understand the implications of technology adoption in a hitherto non ICT-oriented sector. In the study, a random sample of 302 was drawn from an approximate population of 1,400 indigenous medicine practitioners and administrators. From this sample. 280 respondents provided empirical data for a statistical analysis and demographic data for a thorough understanding ofthe indigenous healthcare sector. An overwhelming majority of 267 respondents positively identified with initiatives for an e-health system for the indigenous medicine sector. This research study revealed the need for a coding system for all classifications of data sets in the indigenous medicine sector and an outcome ofthe study was such a coding system prepared through the perusal of many Ayurveda textbooks, other publications relevant to coding and classification systems, and interactions with pioneers in the sector of indigenous medicine. It is expected that the availability of a standard coding scheme would spur the introduction and wide adoption of an ehealth Records System to indigenous medicine sector by modifying existing software systems for the western medicine practice.
item: Conference-Abstract
Evaluation of scalability of hybrid wireless mesh protocol in IEEE 802.11
Sooriyaarachchi, SJ; Fernando, WAC; Gamage, CD
Mobile ad-hoc networks (MANETs) enable ubiquitous computing with wide availability of smart mobile devices and applications. However, robust and lightweight protocols are yet to be implemented for multihop communication. The latest IEEE 802.11 standard released in 2012 captures the concept of muItihop MANETs under Wireless Mesh Networks and proposes Hybrid Wireless Mesh Protocol (HWMP) as the default muItihop path selection protocol. Previous studies on the performance of HWMP have not addressed operating scenarios of mass mobility (to model human user mobility), non-availability of root nodes (to model absence of infrastructure support) and a wide span of node densities (to model different application scenarios). This paper analyses the scalability of HWMP in a MANET of IEEE 802.11 standard wireless mesh stations that move at human walking speeds. The end-to-end delay, data packet delivery ratio and path selection control overhead are evaluated in the presence of random waypoint and mass mobility models for increasing node densities. The simulation results show that there are no significant variations in any of the above important performance metrics among static, random waypoint mobility and mass mobility models. Furthermore, HWMP shows almost a linear path selection control overhead profile for increasing node densities while the packet delivery ratio and the end-to-enddelay reaches a steady level as node density increases up to about 250 nodes.
item: Conference-Abstract
Feature point tracking algorithm evaluation for augmented reality in handheld devices
Perera, A; Pemasiri, A; Wijayarathna, S; Wijebandara, C; Gamage, CD
In augmented reality applications for handheld devices, accuracy and speed of the tracking algorithm are two of the most critical parameters to achieve realism. This paper presents a comprehensive framework to evaluate feature tracking algorithms on these two parameters. While there is a substantial body of knowledge on these aspects, a novel feature introduced in this paper is the use of error associated with the estimated directional movement in performance measurements to improve the evaluation framework. The work described in this paper is a comparative evaluation of nine widely used feature point tracking algorithms using the developed measurement framework and the results are interpreted based on the characteristics of the algorithms as well as the characteristics of test image sequences.
item: Conference-Abstract
A framework for whole-body gesture recognition from video feeds
(Computer Science & Engineering Society c/o Department of Computer Science and Engineering, University of Moratuwa., 2010-09) Thusyanthan, A; Srijeyanthan, K; Kokulakumaran, S; Joseph, CN; Gunasekara, C; Gamage, CD; Gunasekara, C; Wijegunawardana, P; Pavalanathan, U
The growth of technology continues to make both hardware and software affordable and accessible creating space for the emergence of new applications. Rapid growth in computer vision and image processing applications have been evident in recent years. One area of interest in vision and image processing is automated identification of objects in real-time or recorded video streams and analysis of these identified objects. An important topic of research in this context is identification of humans and interpreting their actions. Human motion identification and video processing have been used in critical crime investigations and highly technical applications usually involving skilled human experts. Although the technology has many uses that can be applied in every day activities, it has not been put into such use due to requirements in sophisticated technology, human skill and high implementation costs. This paper presents a system, which is a major part of a project called movelt (movements interpreted), that receives video as input to process and recognize gestures of the objects of interest (the human whole body). Basic functionality of this system is to receive video stream as input and produce outputs gesture analysis of each object through a staged process of object detection, tracking, modelling and recognition of gestures as intermediate steps.
item: Conference-Abstract
A Framework for whole-body gesture recognition from video feeds
(2010) Joseph, CN; Kokulakumaran, S; Srijeyanthan, K; Thusyanthan, A; Gunasekara, C; Gamage, CD
The growth of technology continues to make both hardware and software affordable and accessible creating space for the emergence of new applications. Rapid growth in computer vision and image processing applications have been evident in recent years. One area of interest in vision and image processing is automated identification of objects in real-time or recorded video streams and analysis of these identified objects. An important topic of research in this context is identification of humans and interpreting their actions. Human motion identification and video processing have been used in critical crime investigations and highly technical applications usually involving skilled human experts. Although the technology has many uses that can be applied in every day activities, it has not been put into such use due to requirements in sophisticated technology, human skill and high implementation costs. This paper presents a system, which is a major part of a project called movelt (movements interpreted), that receives video as input to process and recognize gestures of the objects of interest (the human whole body). Basic functionality of this system is to receive video stream as input and produce outputs gesture analysis of each object through a staged process of object detection, classification, modeling, encoding and recognition of gestures as intermediate steps.
item: Article-Abstract
A multi-tenancy aware architectural framework for SaaS application development
(2013) Alwis, WNT; Gamage, CD
In the era of cloud computing, multi-tenant based Software as a Service (SaaS) applications have been widely identified as the next generation of cloud applications. SaaS allows multiple user organizations to customize an application in a reliable and secure manner. However, this customization is a complex and error prone exercise. In response, researchers and practitioners have come up with SaaS architectures based on frameworks, platforms and modelling approaches to ease the complexity of SaaS application development. However, these methods and tools have not focused on aspect of development methodology being tuned to support long-term maintenance of the SaaS application. This paper presents an architectural framework for SaaS application development that incorporates long-term maintenance requirements arising from multi-tenancy of the application. It consists of a methodology coupled with a tool chain, which brings multi-tenancy aware features to develop SaaS solutions that meet critical architectural requirements. It also includes a UML 2.0 based Profile named SaaSML for designing of main components, a skeletal framework to position these components and a methodology for benchmark evaluation of key design criteria.
item: Conference-Abstract
An Online lighting model estimation using neural networl(s for augmented reality in handheld devices
(2015) Pemasiri, A; Wijebandara, C; Wijayarathna, S; Perera, A; Gamage, CD
The level of realism in augmented reality applications is heavily dependent on the consistency of illumination between real objects and virtual objects. This paper presents a comprehensive methodology to model the real world lighting and synthesize it with virtual objects which are rendered. While there is a substantial body of knowledge on this aspect, the novel methodology suggested in this paper has its own advantages of not having to have any prior knowledge on the environment or any special hardware, which increases the usability of the system while making it possible to be utilized in online systems.
item: Conference-Abstract
Privacy enhanced data management for an electronic identity system
(2009) Nimalaprakasan, S; Ramanan, S; Malalasena, BA; Shayanthan, K; Gamage, CD; Fernando, MSD
The electronic identity (eID) is being positioned to be a basic tool for identification, authentication and authorization in application domains ranging from eCommerce in private sector to eGovernance in public sector. A practical and flexible eID should be usable in both a network-connected online setting as well as in conventional offline situations. While improving security of communication and enhancing access control to resources, eID schemes also have the potential to become a serious negative factor on user privacy rights. This paper discusses the specific issue of privacy protection in eID systems and considers a range of solutions that could be implemented in a privacy-enhanced eID system featuring both data access and data management.
item: Conference-Abstract
Quantitative and qualitative evaluation of performance and robustness of image stitching algorithms
Dissanayake, V; Herath, S; Rasnayaka, S; Seneviratne, S; Vidanaarachchi, R; Gamage, CD
Many different image stitching algorithms, and mechanisms to assess their quality have been proposed by different research groups in the past decade. However, a comparison across different stitching algorithms and evaluation mechanisms has not been performed before. Our objective is to recognize the best algorithm for panoramic image stitching. We measure the robustness of different algorithms by means of assessing image quality of a set of panoramas. For the evaluation itself, a varied set of assessment criteria are used, and the evaluation is performed over a large range of images captured using differing cameras. In an ideal stitching algorithm, the resulting stitched image should be without visible seams and other noticeable anomalies. An objective evaluation for image quality should give results corresponding to a similar evaluation by the Human Visual System. Our conclusion is that the choice of stitching algorithm is scenario dependent, with run-time and accuracy being the primary considerations.
item: Thesis-Full-text
Routing and control mechanisms for dense mobile adhoc networks
(2016-09) Sooriyaarachchi, SJ; Gamage, CD
It is not an exaggeration to mention that mobile devices have become ubiquitous and they are used for variety of purposes ranging from personal communication to disaster management and more. These devices are capable of establishing mobile ad hoc networks (MANETs) for multihop communication without the support of infrastructure. This enables more interesting and useful applications of mobile devices, for example for collaborative leaners in large classrooms, shoppers in crowded shopping malls, spectators in sports stadiums, online gamers and more. MANETs have not sufficiently developed to a deployable level yet. Routing in MANETs is a major problem. It is challenging to devise routing protocols for MANETs due to dynamic topology resulting from mobility, limited battery life and impairments inherent in wireless links. Traditional routing approach is to tweak the existing routing protocols that are designed for wired networks. Therefore, it is common to appoint special nodes to perform routing controls and gather global state information such as routing tables. We identify this approach as the fixed-stateful routing paradigm. Fixed stateful routing does not scale with the density of MANETs because the routes will get obsolete quickly due to the dynamic topology causing frequent routing updates. The overhead for these frequent updates will be unacceptable when the MANETs become dense. For example, the control overhead of routing updates in most of the traditional routing protocols are of magnitude O(N) or O(N2), where N is the number of nodes in the network. We name the routing approach that does not require to maintain global network states and does not appoint key nodes for routing and control as mobile-stateless routing paradigm. We propose a novel concept called endcast that leverages message flooding for end to end communication in MANETs in mobile-stateless manner. However, flooding causes heavy amounts of redundant messages, contention and collisions resulting in a situation known as broadcast storm problem. When flooding is utilized for end to end communication, the messages will flood beyond the destination. We call this situation broadcast flood problem. Repetitive rebroadcasting in simple flooding is analogous to biological cell division in the growth of human organs. Chalone mechanism is a regulatory system to control the growth of the organs. In this mechanism, each biological cell secretes a molecule called chalone and the concentration of chalones in the environment increases when the number of cells increases. When the chalone concentration exceeds a threshold the cells stop dividing themselves. Counter based flooding is one of the efficient flooding schemes, in which a node decides not to rebroadcast a received message if the message is subsequently heard multiple times exceeding a predefined threshold during a iv v random wait period. Inspired by the chalone mechanism in the growth of the organs we selected counter based flooding to unicast messages in a MANET. We proposed an inhibition scheme to stop the propagation of message beyond the destination to mitigate the broadcast flood problem. In this scheme, the destination transmits a smaller size control message that we call inhibitor that also propagates using counter based flooding but with a smaller random wait period than in the case of data message. Furthermore, inhibitors are limited to the region of the MANET covered by data flooding. The proposed endcast scheme outperforms simple flooding in such a way that over 45% of redundant messages are saved in all the network configurations starting from 100-node network in ideal wireless conditions when the nodes were placed on a playground of 600m 400m and each node was configured to have 200m of transmission radius. Similarly, the protocol manages to save over 45% of redundant messages for all node densities ranging from 10 to 300 in realistic wireless conditions simulated by IEEE 802.11g standard wireless MAC implementation with power saving transmission radius of 40m. This saving increases rapidly as networks grow by size in both the ideal and realistic wireless network conditions. The inhibition scheme of the protocol was also found to be effective, for example, redundant messages grow in number at a rate about 8 frames per every 25 nodes added to the network when there is inhibition in operation whereas the growth rate is about 170 frames per every 25 nodes when the protocol operates without inhibition in the simulated network scenario. The major contribution of this research is the analytical model that we developed to design and evaluate endcast schemes. We developed a graph theoretic model to evaluate the propagation of messages in endcast, based on a preliminary model developed by Viswanath and Obraczka [2]. We modified the model by (i) improving its method of estimating the number of new nodes reached by each level of rebroadcast (ii) modeling the impact of node mobility and (iii) incorporating time domain representation to model the flooding schemes that involve random assessment delays (iii) enabling it to represent efficient flooding schemes such as counter based flooding. We present the process of estimating the area covered by the propagation of flooding messages using a geometric method. Time domain is represented by indesing the edges of the flooding graph by time. The counter value and the threshold in counter based flooding are converted into a rebroadcasting probability and estimated using a probability mass function that we constructed by considering the overlapping of radio range circles of the nodes.
item: Thesis-Abstract
Security threats and attacks on virtualization for cloud computing
(2012) Dayananda, KS; Gamage, CD
Enterprises continuously seek innovative approaches to reduce operational computing costs while getting the most from their resources. Cloud Comput- ing infrastructures are the latest technological advancement with the potential to maximize resource utilization while reducing costs. The new paradigm of Cloud Computing possesses severe security risks to its adopters due to the distributed nature of Cloud Computing environments which make them a rich target for malicious individuals. Cloud infrastructure commonly relies on virtualization. The virtualization techniques used in Cloud possess numerous security threats and attacks. In order to cope with these risks, appropriate taxonomies and classi cation criteria for attacks on Cloud Computing are required. On the other hand Cloud Consumers runs numerous applications/scripts in order to complete their computing tasks. Most of them are too complex and complicated to trust. Even with access to the source code, it is di cult to reason about the security of these applications. They might harbor malicious code such as computer viruses, worms, bots, Trojan horses and spyware or contain bugs that are exploitable by carefully crafted input. It is essential that instead of just relying on conventional defense techniques, the next generation of system software must be designed from the ground-up to provide stronger isolation of services running on computer systems. To address the above described security threats to Cloud Instances, we propose an architecture for con ned execution environment to test untrusted applications/scripts inside Cloud Instances. Modern day security researchers consider malware sandbox analysis is as one of the promising approaches for exploring malware. But most of the previous proposed solutions have various security vulnerabilities due to the way of they have been implemented and the technologies that have been used in the implementation. The proposed architecture and proof-of-concept implementation address all the discovered drawbacks of previously presented sandbox solutions. We monitor all the sys- tem calls that are executed by the adversary to con ne the adversary and limit the damage an attacker can cause to the Cloud Instance. The research work related to the proposed sandbox architecture has been tested through LangshaJail, which is the proof-of-concept, built for the Cloud vii Instances, using latest open source technologies that includes Linux as the Operating System Environment, Linux Resource Containers (LXC) as the vir- tualization environment and Seccomp as the system call ltering technology. The LangshaJail system was tested for compliance to Cloud Computing secu- rity objectives and adherence to performance criteria in order to validate the design approaches and implementation mechanisms used in the research. Further as a part of the this thesis we present a taxonomy based on the notion of attack surfaces of virtualization for Infrastructure-as-a-Service-based Cloud o erings, thus making them more concrete and improving their analysis. The presented taxonomy specially addresses attacks based on residues of Cloud Instances. These residue based attacks are new venues for attackers that have previously not been addressed.
item: Thesis-Abstract
Software industry developmental trends in Sri Lanka
(2016-07-09) Gunasingha, WART; Gamage, CD
Software industry is a growing industry in Sri Lanka in the recent decades. It brings more foreign currency to Sri Lanka and provides more employment opportunities to the graduates who pass out from universities. As Sri Lanka has a highly skilled and talented workforce, Sri Lankan software companies would be able to compete with the global software companies to provide sophisticated software products necessary for the global market. That is, the development of the software industry would be able to bring more benefits to the Sri Lankan economy. This research investigates the software industry developmental trends in Sri Lanka. There are five independent variables, three intervening variables and one dependent variable identified in the context. They are namely: software industry related investments, software industry related recruitments, the number of students passed out from universities, software policy, domestic software industry development, revenue earned from software exports, economic conditions of the country, global software industry constraints and software industry development. Considering some of the relationships between these variables three hypothesis were developed to predict the future of the software industry in Sri Lanka. Also, statistical data analysis using SPSS and Minitab software packages was used to forecast the development of software industry related investments, software industry related recruitments and the number of ICT graduates passed out from universities. This was useful in determining the development of the factors that affected in developing the software industry in Sri Lanka. According to the research, there would be a higher development in software industry in Sri Lanka in the future. Therefore, the government of Sri Lanka should plan for the future of the software industry focusing the factors that have mainly affected in developing the software industry.
item: Conference-Abstract
Speeding up data access in SOA
Lokumarambage, M; Gamage, CD
Service Oriented Architecture (SOA) is a paradigm that can be used to build complex enterprise architectures enabling clients with needs and servers with capabilities to interact via services across disparate platforms, technologies, and ownership domains. An Enterprise Service Bus (ESB), which is the most common realization of a SOA, enables smooth operation among diverse Enterprise Applications. However, this agility and scalability of SOA comes at a price on performance. The objective of the research presented in this paper is to characterize the performance of SOA in the presence of an ESB and provide a framework for performance tuning.
item: Conference-Abstract
Versatile privacy preserving electronic identity framework
(2009) Malalasena, BA; Nimalaprakasan, S; Ramanan, S; Shayanthan, S; Gamage, CD; Fernando, MSD
For eGovernment and eBusiness to function to their full potential, people need a secure, convenient and effective way of identifying themselves. Electronic Identity systems draw the fundamental basics for the Implementation of full range of eGovernment services, for both citizens and businesses. Privacy and security issues play a vital role in user acceptance of any electronic identity system, which decides the success of the system.