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Full-Text Articles in Computer Engineering

Ict For Poverty Alleviation In Pacific Island Nations: Study Of Icts4d In Fiji, Deogratias Harorimana, Opeti Rokotuinivono, Emali Sewale, Fane Salaiwai, Marica Naulu, Evangelin Roy Dec 2012

Ict For Poverty Alleviation In Pacific Island Nations: Study Of Icts4d In Fiji, Deogratias Harorimana, Opeti Rokotuinivono, Emali Sewale, Fane Salaiwai, Marica Naulu, Evangelin Roy

Dr Deogratias Harorimana

ICT for Poverty Alleviation in Pacific Island Nations: Study of ICTs4D in Fiji There has been a vague and little knowledge on the role or potential of Information and Communications Technologies (ICTs) in relation to addressing poverty in Fiji. This may be probably due to the newness of the technology in the South Pacific Region as a whole but also probably due to the fact that only 9.7% of the current Fiji 931,000 populations are internet users (ITC Figures 2011). This paper reports on finding how ICTs is contributing towards poverty alleviation in Fiji. On the basis of ...


Comments On "A Practical (T, N) Threshold Proxy Signature Scheme Based On The Rsa Cryptosystem", Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng Dec 2012

Comments On "A Practical (T, N) Threshold Proxy Signature Scheme Based On The Rsa Cryptosystem", Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Dr Guilin Wang

In a (t, n) threshold proxy signature scheme based on RSA, any t or more proxy signers can cooperatively generate a proxy signature while t-1 or fewer of them can't do it. The threshold proxy signature scheme uses the RSA cryptosystem to generate the private and the public key of the signers. In this article, we discuss the implementation and comparison of some threshold proxy signature schemes that are based on the RSA cryptosystem. Comparison is done on the basis of time complexity, space complexity and communication overhead. We compare the performance of four schemes: Hwang et al., Wen ...


Proxy Signature Scheme With Multiple Original Signers For Wireless E-Commerce Applications, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng Dec 2012

Proxy Signature Scheme With Multiple Original Signers For Wireless E-Commerce Applications, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Dr Guilin Wang

In a proxy signature scheme, a user delegates his/her signing capability to another user in such a way that the latter can sign messages on behalf of the former. We propose an efficient and secure proxy signature scheme with multiple original signers. Our scheme is suitable for wireless electronic commerce applications, since the overheads of computation and communication are low. As an example, we present an electronic air ticket booking scheme for wireless customers.


At The Tone, The Time Will Be... Unknown – A Perspective On The Evolution Of Time In Telecommunications, Robert Iannucci Oct 2012

At The Tone, The Time Will Be... Unknown – A Perspective On The Evolution Of Time In Telecommunications, Robert Iannucci

Robert A Iannucci

No abstract provided.


Wispernet: Anti-Jamming For Wireless Sensor Networks, Miroslav Pajic, Rahul Mangharam Oct 2012

Wispernet: Anti-Jamming For Wireless Sensor Networks, Miroslav Pajic, Rahul Mangharam

Rahul Mangharam

Resilience to electromagnetic jamming and its avoidance are difficult problems. It is often both hard to distinguish malicious jamming from congestion in the broadcast regime and a challenge to conceal the activity patterns of the legitimate communication protocol from the jammer. In the context of energy-constrained wireless sensor networks, nodes are scheduled to maximize the common sleep duration and coordinate communication to extend their battery life. This results in well-defined communication patterns with possibly predictable intervals of activity that are easily detected and jammed by a statistical jammer. We present an anti-jamming protocol for sensor networks which eliminates spatio-temporal patterns ...


Anti-Jamming For Embedded Wireless Networks, Miroslav Pajic, Rahul Mangharam Oct 2012

Anti-Jamming For Embedded Wireless Networks, Miroslav Pajic, Rahul Mangharam

Rahul Mangharam

Resilience to electromagnetic jamming and its avoidance are difficult problems. It is often both hard to distinguish malicious jamming from congestion in the broadcast regime and a challenge to conceal the activity patterns of the legitimate communication protocol from the jammer. In the context of energy-constrained wireless sensor networks, nodes are scheduled to maximize the common sleep duration and coordinate communication to extend their battery life. This results in well-defined communication patterns with possibly predictable intervals of activity that are easily detected and jammed by a statistical jammer. We present an anti-jamming protocol for sensor networks which eliminates spatio-temporal patterns ...


Embedded Virtual Machines For Robust Wireless Control Systems, Rahul Mangharam, Miroslav Pajic Oct 2012

Embedded Virtual Machines For Robust Wireless Control Systems, Rahul Mangharam, Miroslav Pajic

Rahul Mangharam

Embedded wireless networks have largely focused on open loop sensing and monitoring. To address actuation in closed loop wireless control systems there is a strong need to re-think the communication architectures and protocols for reliability, coordination and control. As the links, nodes and topology of wireless systems are inherently unreliable, such time-critical and safety-critical applications require programming abstractions where the tasks are assigned to the sensors, actuators and controllers as a single component rather than statically mapping a set of tasks to a specific physical node at design time. To this end, we introduce the Embedded Virtual Machine (EVM), a ...


Embedded Virtual Machines For Robust Wireless Control And Actuation, Miroslav Pajic, Rahul Mangharam Oct 2012

Embedded Virtual Machines For Robust Wireless Control And Actuation, Miroslav Pajic, Rahul Mangharam

Rahul Mangharam

Embedded wireless networks have largely focused on open-loop sensing and monitoring. To address actuation in closed-loop wireless control systems there is a strong need to re-think the communication architectures and protocols for reliability, coordination and control. As the links, nodes and topology of wireless systems are inherently unreliable, such time-critical and safety-critical applications require programming abstractions and runtime systems where the tasks are assigned to the sensors, actuators and controllers as a single component rather than statically mapping a set of tasks to a specific physical node at design time. To this end, we introduce the Embedded Virtual Machine (EVM ...


International Ict Research Collaboration: Experiences And Recommendations, Erich Prem, Emma Barron, Arcot Desai Narasimhalu, Ian Morgan Jul 2012

International Ict Research Collaboration: Experiences And Recommendations, Erich Prem, Emma Barron, Arcot Desai Narasimhalu, Ian Morgan

Arcot Desai NARASIMHALU

This paper presents results of a study into the collaboration experiences of researchers. The focus is on long-distance collaboration in information and communication technologies (ICT) research and technology development, i.e. between the EU on the one side and Australia, Singapore or New Zealand on the other. The aim of the study was to provide useful recommendations for researchers who engage in international collaboration and to improve the quality of international co-operation projects. The emphasis here is on the views and experiences of Europe"s international partners. The paper analysis collaboration motives, challenges, co-operation types and provides recommendations for project ...


Lachesis: A Job Scheduler For The Cray T3e, Allen B. Downey Jul 2012

Lachesis: A Job Scheduler For The Cray T3e, Allen B. Downey

Allen B. Downey

This paper presents the design and implementation of Lachesis, a job scheduler for the Cray T3E. Lachesis was developed at the San Diego Supercomputer Center (SDSC) in an attempt to correct some problems with the scheduling system Cray provides with the T3E.


A Parameterized Stereo Vision Core For Fpgas, Mark Chang, Stephen Longfield Jul 2012

A Parameterized Stereo Vision Core For Fpgas, Mark Chang, Stephen Longfield

Mark L. Chang

We present a parameterized stereo vision core suitable for a wide range of FPGA targets and stereo vision applications. By enabling easy tuning of algorithm parameters, our system allows for rapid exploration of the design space and simpler implementation of high-performance stereo vision systems. This implementation utilizes the census transform algorithm to calculate depth information from a pair of images delivered from a simulated stereo camera pair. This work advances our previous work through implementation improvements, a stereo camera pair simulation framework, and a scalable stereo vision core.


Precis: A Usercentric Word-Length Optimization Tool, Mark Chang, Scott Hauck Jul 2012

Precis: A Usercentric Word-Length Optimization Tool, Mark Chang, Scott Hauck

Mark L. Chang

Translating an algorithm designed for a general-purpose processor into an algorithm optimized for custom logic requires extensive knowledge of the algorithm and the target hardware. Precis lets designers analyze the precision requirements of algorithms specified in Matlab. The design time tool combines simulation, user input, and program analysis to help designers focus their manual precision optimization efforts.


Low-Cost Stereo Vision On An Fpga, Chris A. Murphy, Daniel Lindquist, Ann Marie Rynning, Thomas Cecil, Sarah Leavitt, Mark L. Chang Jul 2012

Low-Cost Stereo Vision On An Fpga, Chris A. Murphy, Daniel Lindquist, Ann Marie Rynning, Thomas Cecil, Sarah Leavitt, Mark L. Chang

Mark L. Chang

We present a low-cost stereo vision implementation suitable for use in autonomous vehicle applications and designed with agricultural applications in mind. This implementation utilizes the Census transform algorithm to calculate depth maps from a stereo pair of automotive-grade CMOS cameras. The final prototype utilizes commodity hardware, including a Xilinx Spartan-3 FPGA, to process 320times240 pixel images at greater than 150 frames per second and deliver them via a USB 2.0 interface.


Automated Least-Significant Bit Datapath Optimization For Fpgas, Mark L. Chang, Scott Hauck Jul 2012

Automated Least-Significant Bit Datapath Optimization For Fpgas, Mark L. Chang, Scott Hauck

Mark L. Chang

In this paper, we present a method for FPGA datapath precision optimization subject to user-defined area and error constraints. This work builds upon our previous research which presented a methodology for optimizing the dynamic range- the most significant bit position. In this work, we present an automated optimization technique for the least-significant bit position of circuit datapaths. We present results describing the effectiveness of our methods on typical signal and image processing kernels.


Strategyproof Mechanisms For Ad Hoc Network Formation, C. Jason Woodard, David C. Parkes Apr 2012

Strategyproof Mechanisms For Ad Hoc Network Formation, C. Jason Woodard, David C. Parkes

C. Jason Woodard

Agents in a peer-to-peer system typically have incentives to influence its network structure, either to reduce their costs or increase their ability to capture value. The problem is compounded when agents can join and leave the system dynamically. This paper proposes three economic mechanisms that offset the incentives for strategic behavior and facilitate the formation of networks with desirable global properties.


Modeling Product Development As A System Design Game, C. Jason Woodard Apr 2012

Modeling Product Development As A System Design Game, C. Jason Woodard

C. Jason Woodard

A system design game is a model of a situation in which agents’ actions determine the structure of a system, which in turn affects the system’s value and the share of value that each agent may capture through bargaining or market competition. This paper describes a class of games in which agents design interdependent products, for example software programs, which may be complements or substitutes for each other. These relationships are epresented by an object called a design structure network (DSN). Depending on the modeler’s choice of allocation rules, agents may benefit from owning critical nodes in the ...


Modeling Architectural Strategy Using Design Structure Networks, C. Jason Woodard Apr 2012

Modeling Architectural Strategy Using Design Structure Networks, C. Jason Woodard

C. Jason Woodard

System architects face the formidable task of purposefully shaping an evolving space of complex designs. Their task s further complicated when they lack full control of the design process, and therefore must anticipate the behavior of other stakeholders, including the designers of component products and competing systems. This paper presents a conceptual tool called a design structure network (DSN) to help architects and design scientists reason effectively about these situations. A DSN is a graphical representation of a system’s design space. DSNs improve on existing representation schemes by providing a compact and intuitive way to express design options—the ...


On The Coordinated Navigation Of Multiple Independent Disk-Shaped Robots, Cem Serkan Karagöz, H. Isil Bozma, Daniel Koditschek Mar 2012

On The Coordinated Navigation Of Multiple Independent Disk-Shaped Robots, Cem Serkan Karagöz, H. Isil Bozma, Daniel Koditschek

Daniel E Koditschek

This paper addresses the coordinated navigation of multiple independently actuated disk-shaped robots - all placed within the same disk-shaped workspace. Assuming perfect sensing, shared centralized communications and computation, as well as perfect actuation, we encode complete information about the goal, obstacles and workspace boundary using an artificial potential function over the cross product space of the robots’ simultaneous configurations. The closed-loop dynamics governing the motion of each robot take the form of the appropriate projection of the gradient of this function. We show, with some reasonable restrictions on the allowable goal positions, that this function is an essential navigation function - a ...


Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas Mar 2012

Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas

George J. Pappas

We consider deployment problems where a mobile robotic network must optimize its configuration in a distributed way in order to minimize a steady-state cost function that depends on the spatial distribution of certain probabilistic events of interest. Three classes of problems are discussed in detail: coverage control problems, spatial partitioning problems, and dynamic vehicle routing problems. Moreover, we assume that the event distribution is a priori unknown, and can only be progressively inferred from the observation of the location of the actual event occurrences. For each problem we present distributed stochastic gradient algorithms that optimize the performance objective. The stochastic ...


Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas Mar 2012

Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas

George J. Pappas

We consider deployment problems where a mobile robotic network must optimize its configuration in a distributed way in order to minimize a steady-state cost function that depends on the spatial distribution of certain probabilistic events of interest. Three classes of problems are discussed in detail: coverage control problems, spatial partitioning problems, and dynamic vehicle routing problems. Moreover, we assume that the event distribution is a priori unknown, and can only be progressively inferred from the observation of the location of the actual event occurrences. For each problem we present distributed stochastic gradient algorithms that optimize the performance objective. The stochastic ...


Modeling And Analysis Of Multi-Hop Control Networks, Alur Rajeev, Alessandro D'Innocenzo, Karl H. Johansson, George James Pappas, Gera Weiss Mar 2012

Modeling And Analysis Of Multi-Hop Control Networks, Alur Rajeev, Alessandro D'Innocenzo, Karl H. Johansson, George James Pappas, Gera Weiss

George J. Pappas

We propose a mathematical framework, inspired by the Wireless HART specification, for modeling and analyzing multi-hop communication networks. The framework is designed for systems consisting of multiple control loops closed over a multi-hop communication network. We separate control, topology, routing, and scheduling and propose formal syntax and semantics for the dynamics of the composed system. The main technical contribution of the paper is an explicit translation of multi-hop control networks to switched systems. We describe a Mathematica notebook that automates the translation of multihop control networks to switched systems, and use this tool to show how techniques for analysis of ...


Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas Mar 2012

Adaptive Algorithms For Coverage Control And Space Partitioning In Mobile Robotic Networks, Jerome Le Ny, George J. Pappas

George J. Pappas

We consider deployment problems where a mobile robotic network must optimize its configuration in a distributed way in order to minimize a steady-state cost function that depends on the spatial distribution of certain probabilistic events of interest. Three classes of problems are discussed in detail: coverage control problems, spatial partitioning problems, and dynamic vehicle routing problems. Moreover, we assume that the event distribution is a priori unknown, and can only be progressively inferred from the observation of the location of the actual event occurrences. For each problem we present distributed stochastic gradient algorithms that optimize the performance objective. The stochastic ...


Modeling And Analysis Of Multi-Hop Control Networks, Alur Rajeev, Alessandro D'Innocenzo, Karl H. Johansson, George James Pappas, Gera Weiss Mar 2012

Modeling And Analysis Of Multi-Hop Control Networks, Alur Rajeev, Alessandro D'Innocenzo, Karl H. Johansson, George James Pappas, Gera Weiss

George J. Pappas

We propose a mathematical framework, inspired by the Wireless HART specification, for modeling and analyzing multi-hop communication networks. The framework is designed for systems consisting of multiple control loops closed over a multi-hop communication network. We separate control, topology, routing, and scheduling and propose formal syntax and semantics for the dynamics of the composed system. The main technical contribution of the paper is an explicit translation of multi-hop control networks to switched systems. We describe a Mathematica notebook that automates the translation of multihop control networks to switched systems, and use this tool to show how techniques for analysis of ...


Polaris: Getting Accurate Indoor Orientations For Mobile Devices Using Ubiquitous Visual Patterns On Ceilings, Zheng Sun Feb 2012

Polaris: Getting Accurate Indoor Orientations For Mobile Devices Using Ubiquitous Visual Patterns On Ceilings, Zheng Sun

Zheng Sun

Ubiquitous computing applications commonly use digital compass sensors to obtain orientation of a device relative to the magnetic north of the earth. However, these compass readings are always prone to significant errors in indoor environments due to presence of metallic objects in close proximity. Such errors can adversely affect the performance and quality of user experience of the applications utilizing digital compass sensors.

In this paper, we propose Polaris, a novel approach to provide reliable orientation information for mobile devices in indoor environments. Polaris achieves this by aggregating pictures of the ceiling of an indoor environment and applies computer vision ...


Understanding User Generated Content Characteristics : A Hot-Event Perspective, Miao Wang, Guodong Li, Jie Feng, Lisong Xu, Byrav Ramamurthy, Wei Li, Xiaohong Guan Feb 2012

Understanding User Generated Content Characteristics : A Hot-Event Perspective, Miao Wang, Guodong Li, Jie Feng, Lisong Xu, Byrav Ramamurthy, Wei Li, Xiaohong Guan

Miao Wang

Nowadays, millions of Internet users watch and upload a large number of videos on User Generated Content (UGC) sites (e.g., Youtube) everyday. Moreover, online videos about hot events, such as breaking news and Olympic games, attract lots of users. In this paper, we study the characteristics of hot-event videos by collecting video traces of the largest UGC site in China for 28 days. We first empirically study statistical properties of such videos and find that hot-event videos contribute a large number of views, even though the total number of hotevent videos is relatively small. In addition, there exist extremely ...


Multi-Channel Peer-To-Peer Streaming Systems As Resource Allocation Problems, Miao Wang Feb 2012

Multi-Channel Peer-To-Peer Streaming Systems As Resource Allocation Problems, Miao Wang

Miao Wang

In the past few years, the Internet has witnessed the success of Peer-to-Peer (P2P) streaming technology, which has attracted millions of users. More recently, commercial P2P streaming systems have begun to support multiple channels and a user in such systems is allowed to watch more than one channel at a time. We refer to such systems as multi-channel P2P streaming systems. In this dissertation, we focus on designing multi-channel P2P streaming systems with the goal of providing optimal streaming quality for all channels, termed as system-wide optimal streaming quality. Specifically, we design the systems from the perspective of how to ...


Social Networks And Web2.0 Among Youth: Lessons For Pacific Island Nations, Deogratias Harorimana Sr Feb 2012

Social Networks And Web2.0 Among Youth: Lessons For Pacific Island Nations, Deogratias Harorimana Sr

Dr Deogratias Harorimana

This study is on social networks and web2 among youths and the lessons for Pacific Island nation. This study defines commonly used social networking sites used by the Pacific youths, average time spent, reasons behind the use of social networking sites and how social networking sites can be used as a development tool for Pacific Island nation. It was found that the popularity of social networking amongst youths in Pacific Island Countries is fast growing, increasing more than three folds year on year in the last 3years. Social Networks are a vital part of life for PIC youths, where, now ...


Naked Object File System (Nofs): A Framework To Expose An Object-Oriented Domain Model As A File System, Joseph P. Kaylor, Konstantin Läufer, George K. Thiruvathukal Jan 2012

Naked Object File System (Nofs): A Framework To Expose An Object-Oriented Domain Model As A File System, Joseph P. Kaylor, Konstantin Läufer, George K. Thiruvathukal

Konstantin Läufer

We present Naked Objects File System (NOFS), a novel framework that allows a developer to expose a domain model as a file system by leveraging the Naked Objects design principle. NOFS allows a developer to construct a file system without having to understand or implement all details related to normal file systems development. In this paper we explore file systems frameworks and object-oriented frameworks in a historical context and present an example domain model using the framework. This paper is based on a fully-functional implementation that is distributed as free/open source software, including virtual machine images to demonstrate and ...