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2007

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Articles 361 - 390 of 1355

Full-Text Articles in Computer Sciences

An Integrated Framework For Enhancing User Experience For Different Data Services In Multi-Rate Wireless Systems, Sourav Pal Aug 2007

An Integrated Framework For Enhancing User Experience For Different Data Services In Multi-Rate Wireless Systems, Sourav Pal

Computer Science and Engineering Dissertations - Archive

Technological advances in multi\--rate wireless systems have made wireless data services an intrinsic part of human life. An abundance of wireless devices, both in the wireless enabled home multimedia systems as well as in corporate offices, have trigerred an array of research in enhancing the wireless data services. The success and acceptance of these various rich data services Technological advances in multi\--rate wireless systems have made wireless data services an intrinsic part of human life. An abundance of wireless devices, both in the wireless enabled home multimedia systems as well as in corporate offices, have trigerred an array of research …


Enhanced Targeting In A Haptic User Interface For The Physically Disabled Using A Force Feedback Mouse, Brian Holbert Aug 2007

Enhanced Targeting In A Haptic User Interface For The Physically Disabled Using A Force Feedback Mouse, Brian Holbert

Computer Science and Engineering Dissertations - Archive

Although the human computer interface continues to evolve by engaging sight, voice, sound, and touch to manipulate the environment, the marriage between mouse and graphic based operating systems remains one of the primary relationships through which we interact with the computer. With the advent of haptics it has become possible to enhance the GUI/mouse relationship with the sense of touch using a haptic mouse, opening new avenues of interaction, in particular for those with disabilities. For the majority of users the mouse is an effective and proven device for human computer interaction. However it is not as well suited for …


Building Energy-Efficient Broadcast Trees Using A Genetic Algorithm In Wireless Sensor Networks, Min Kyung An Aug 2007

Building Energy-Efficient Broadcast Trees Using A Genetic Algorithm In Wireless Sensor Networks, Min Kyung An

Computer Science and Engineering Theses - Archive

In wireless broadcast environment, data can be transmitted to several nodes by a single transmission. The nodes in that environment have limited energy resources; therefore we need to reduce the energy consumption when they broadcast data to all nodes to prolong the lifetime of the networks. We call this problem the MPB (minimum power broadcast) problem, and solving the problem has been shown to be an NP-Complete problem [2], [11]. We focus on finding 'near-optimal' solutions for the problem. An algorithm for constructing the minimum power broadcast trees, named BIP (broadcast incremental power) algorithm, was first proposed by Wieselthier et …


M-Infosift : A Graph-Based Approach For Multiclass Document Classification, Aravind Venkatachalam Aug 2007

M-Infosift : A Graph-Based Approach For Multiclass Document Classification, Aravind Venkatachalam

Computer Science and Engineering Theses - Archive

With the increase in the amount of data being introduced into the Internet on a daily basis, the problem of managing large amount of data is an unavoidable problem. The area of document classification has been examined, explored and experimented as a technique for organizing and managing vast repositories of electronic documents such as emails, text and web pages. Over the past decade, several approaches such as machine learning, data mining, information retrieval and others have been proposed for addressing this problem of classifying electronic documents. While a majority of these techniques rely on extracting high-frequency keywords, they ignore the …


Resource Adaptive Agent Based Fault Tolerant Architecture, Shreyas Shetty Aug 2007

Resource Adaptive Agent Based Fault Tolerant Architecture, Shreyas Shetty

Computer Science and Engineering Theses - Archive

Pervasive environment consists of increasing number of mobile, tiny and heterogeneous devices communicating through interconnected network. As ubiquitous computing has seeped into various aspects of everyday life, there has been an increasing demand for dependable systems. However providing reliability demands fault tolerance mechanisms that require substantial time and resources. The dynamic nature and the uncertainty associated with pervasive systems coupled with the energy constraints of the devices involved makes fault tolerance a challenging task. In general, the techniques used to provide fault-tolerance are based on having redundancy and duplication of the user tasks. However the additional cost and the low …


Incremental Retrieval And Ranking Of Complex Patterns From Text Repositiories, Jayakrishna Thathireddy Aug 2007

Incremental Retrieval And Ranking Of Complex Patterns From Text Repositiories, Jayakrishna Thathireddy

Computer Science and Engineering Theses - Archive

As the volume of information accessible via the electronic medium (such as the Internet) is staggeringly large and growing rapidly, users have to sift through vast reservoirs of information to retrieve relevant data of their choice. It has been estimated that, the Internet consists of 2.5 billion unique, publicly accessible web-pages and this figure is growing at an alarming rate of 7.3 million pages per day. Currently, the only way to wade through such colossal information is by using search engines (such as Google, Live, Yahoo, etc.). Although the popularity of search engines has increased manifold due to -- simplicity …


Top K Query Processing In Distributed Database, Amrita Tamrakar Aug 2007

Top K Query Processing In Distributed Database, Amrita Tamrakar

Computer Science and Engineering Theses - Archive

Today's data is rarely stored in centralized location due to the enormous amount of information that needs to be stored and also to increase reliability, availability and performance of the system. Same data is stored in different format into different company's database as well as they may be partitioned or replicated. We consider various scenarios of distributed database such as horizontal, vertical fragmentation and attribute overlapping. Allowing access to integrated information from these multiple datasets can provide accurate and wholesome information to the end-user. We research on efficient querying to these distributed databases to get top k elements matching the …


Sequence Alignment Editor - A New Tool To Assist With Inferring Phylogenetic And Functional Relationships In Biological Data, Ramya Raghukumar Aug 2007

Sequence Alignment Editor - A New Tool To Assist With Inferring Phylogenetic And Functional Relationships In Biological Data, Ramya Raghukumar

Computer Science and Engineering Theses - Archive

Biologists study evolution, discover functional and structural information in genomic or protein data through the extensive use of sequence alignments. It is very difficult to manually align long regions, so development of methods for this task continues to be an active area of research. Alignment construction algorithms, based on dynamic programming, approach the problem from a mathematical perspective. The optimal alignment is computed relative to a scoring scheme. The resulting layout is guaranteed to be mathematically optimal, though not necessarily biologically meaningful. Sequence alignments usually account only for single letter substitutions and relatively short indels, representing the latter as gaps. …


Performance Analysis Of Caching Effect On Real Time Packet Processing In A Multi-Threaded Processor, Miao Ju Aug 2007

Performance Analysis Of Caching Effect On Real Time Packet Processing In A Multi-Threaded Processor, Miao Ju

Computer Science and Engineering Theses - Archive

Caching has been time proven to be a very effective technique to improve memory access speed and average performance for general processors. Based on the real-world trace simulation, earlier research showed that cache can help improve the route lookup and packet classification performance in a Network Processor (NP). However, the existing studies did not take the packet delay/loss constraints into account. As a result, how effective the caching technique is, in dealing with traffic under stringent delay/loss constraints (as is the case for router interface using an NP for packet processing), is still an open issue. In this thesis, we …


Rate Control Algorithms For Ieee 802.11 Wireless Networks, Bodhisatwa Chakravarty Aug 2007

Rate Control Algorithms For Ieee 802.11 Wireless Networks, Bodhisatwa Chakravarty

Computer Science and Engineering Theses - Archive

This thesis evaluates software driven rate selection algorithms used in IEEE 802.11 wireless network interface cards. The motive of the bit-rate selection techniques is to optimize the throughput over the wireless network out of the many rates that are supported by the IEEE 802.11 link. The decision to switch from one rate to another with the changing link conditions to optimize the throughput is the primary focus of the bit-rate selection algorithms. Due to the uncertainty in the channel quality, it is a challenge to make the correct decision so as to minimize the wastage of network resources and achieve …


Dynamic Push And Pull Strategy Based On Data Interpolation For Web Sensor Networks, Rohita Mohan Aug 2007

Dynamic Push And Pull Strategy Based On Data Interpolation For Web Sensor Networks, Rohita Mohan

Computer Science and Engineering Theses - Archive

Sensor Web, a new trend has been developed recently to effectively network large scale deployed heterogeneous sensors with Internet to make sensor data discoverable, accessible and controllable via World Wide Web. Since sensor nodes are highly resource constrained, continuous back hauling of a large amount of data is not feasible. In this paper, we propose a dynamic push/pull service architecture where sensory quality is dynamically monitored and controlled. The architecture is implemented in a web proxy residing at the gateway of the network. As data is being pushed continuously from the network for effective sketching of the sensing field, interpolation …


A Framework For Improving The Performance Of Application Servers In Next Generation Networks (Ngns), Sumantra R. Kundu Aug 2007

A Framework For Improving The Performance Of Application Servers In Next Generation Networks (Ngns), Sumantra R. Kundu

Computer Science and Engineering Dissertations - Archive

Next generation networks (NGNs) such as IP Multimedia Subsystem (IMS) are completely built on the Internet Protocol (IP) suite. This has made IP the de facto standard for data networking, voice over IP (VoIP), and media rich applications such as streaming multimedia, ringtones, multi-player gaming, and high-definition video conferencing for remote interaction. A primary feature of such converged networks is that they use the same IP-based network for simultaneously delivering voice, video, and data. Such services are provided on application servers built using industry standard Advanced Telecom Computing Architecture (ATCA) based blade computing units with various flavors of commodity open …


Near-Duplicate Keyframe Identification With Interest Point Matching And Pattern Learning, Wan-Lei Zhao, Chong-Wah Ngo, Hung-Khoon Tan, Xiao Wu Aug 2007

Near-Duplicate Keyframe Identification With Interest Point Matching And Pattern Learning, Wan-Lei Zhao, Chong-Wah Ngo, Hung-Khoon Tan, Xiao Wu

Research Collection School Of Computing and Information Systems

This paper proposes a new approach for near-duplicate keyframe (NDK) identification by matching, filtering and learning of local interest points (LIPs) with PCA-SIFT descriptors. The issues in matching reliability, filtering efficiency and learning flexibility are novelly exploited to delve into the potential of LIP-based retrieval and detection. In matching, we propose a one-to-one symmetric matching (OOS) algorithm which is found to be highly reliable for NDK identification, due to its capability in excluding false LIP matches compared with other matching strategies. For rapid filtering, we address two issues: speed efficiency and search effectiveness, to support OOS with a new index …


Channel Management In Heterogeneous Cellular Networks, Mohammad Hadi Arbabi Aug 2007

Channel Management In Heterogeneous Cellular Networks, Mohammad Hadi Arbabi

Computer Science Theses & Dissertations

Motivated by the need to increase system capacity in the face of tight FCC regulations, modem cellular systems are under constant pressure to increase the sharing of the frequency spectrum among the users of the network.

Key to increasing system capacity is an efficient channel management strategy that provides higher capacity for the system while, at the same time, providing the users with Quality of Service guarantees. Not surprisingly, dynamic channel management has become a high profile topic in wireless communications. Consider a highly populated urban area, where mobile traffic loads are increased due to highway backups or sporting events. …


Periodic Properties Of User Mobility And Access-Point Popularity, Minkyong Kim, David Kotz Aug 2007

Periodic Properties Of User Mobility And Access-Point Popularity, Minkyong Kim, David Kotz

Dartmouth Scholarship

Understanding user mobility and its effect on access points (APs) is important in designing location-aware systems and wireless networks. Although various studies of wireless networks have provided useful insights, it is hard to apply them to other situations. Here we present a general methodology for extracting mobility information from wireless network traces, and for classifying mobile users and APs. We used the Fourier transform to reveal important periods and chose the two strongest periods to serve as parameters to a classification system based on Bayes' theory. Analysis of 1-month traces shows that while a daily pattern is common among both …


Exploration Of Dynamic Memory, Delvin Curvin Defoe Aug 2007

Exploration Of Dynamic Memory, Delvin Curvin Defoe

All Computer Science and Engineering Research

Since the advent of the Java programming language and the development of real-time garbage collection, Java has become an option for implementing real-time applications. The memory management choices provided by real-time garbage collection allow for real-time eJava developers to spend more of their time implementing real-time solutions. Unfortunately, the real-time community is not convinced that real-time garbage collection works in managing memory for Java applications deployed in a real-time context. Consequently, the Real-Time for Java Expert Group formulated the Real-Time Specification for Java (RTSJ) standards to make Java a real-time programming language. In lieu of garbage collection, the RTSJ proposed …


The Influence Of Online Word Of Mouth On Product Sales In Retail E-Commerce: An Empirical Investigation, Alanah Davis, Deepak Khazanchi Aug 2007

The Influence Of Online Word Of Mouth On Product Sales In Retail E-Commerce: An Empirical Investigation, Alanah Davis, Deepak Khazanchi

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

The ability to exchange opinions and experiences online is known as online word of mouth (WOM). Due to the high acceptance of consumers and their apparent reliance on online WOM it is important for organizations to understand how it works and what kind of impact it has on product sales. Using the well-established notions of volume and valence to describe online WOM, we empirically evaluate the hypothesized relationship between online WOM in a retail e-commerce site and actual product sales. Our analysis of the data shows that there is a significant change in the number of products sold following the …


An Information Technology Therapy Approach To Micro-Enterprise Adoption Of Icts, Peter Wolcott, Sajda Qureshi, Mehruz Kamal Aug 2007

An Information Technology Therapy Approach To Micro-Enterprise Adoption Of Icts, Peter Wolcott, Sajda Qureshi, Mehruz Kamal

Information Systems and Quantitative Analysis Faculty Proceedings & Presentations

The advent of Information and Communication Technologies (ICTs) has opened up new opportunities for micro-enterprises to improve their businesses. However the challenges to using ICTs are impeding these businesses from growing into the drivers for development that they can be. This suggests that a potentially important driver of development needs to be supported. This paper investigates the adoption of ICTs in eight micro-enterprises in an underserved community of Omaha, Nebraska. Following an action research study, this research provides insight into the key challenges and opportunities facing micro-enterprises in their use of ICTs to create value for their businesses. Its contribution …


Enhanced Security By Os-Oriented Encapsulation In Tpm-Enabled Drm, Yongdong Wu, Feng Bao, Robert H. Deng, Marc Mouffron, Frederic Rousseau Aug 2007

Enhanced Security By Os-Oriented Encapsulation In Tpm-Enabled Drm, Yongdong Wu, Feng Bao, Robert H. Deng, Marc Mouffron, Frederic Rousseau

Research Collection School Of Computing and Information Systems

The Trusted Computing Group (TCG) defines the specifications for the Trusted Platform Module (TPM) and corresponding trust mechanisms that allow a TPM-enabled platform to run only authenticated software. For example, the operating system (OS) can use the facilities provided by the TPM to authenticate a Digital Rights Management (DRM) application before allowing it to run. However TCG does not provide any clear specification on what kind of software can be regarded as trusted and hence be authenticated. In fact it is unlikely that there will be a clear line between the software that should be authenticated and those should not, …


Innovation Stack - Choosing Innovations For Commercialization, Arcot Desai Narasimhalu Aug 2007

Innovation Stack - Choosing Innovations For Commercialization, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

This paper describes a method for enterprises to order the innovations of interest according to a number of parameters including their own business strategy and core competencies. The method takes into account aspects such as ability to create entry barriers and complementary assets. Enterprises can now use this method to both filter out innovations that may not be of interest to them and then order the short listed or selected innovations according to their attractiveness.


Design Science Research On Systems Analysis And Design: The Case Of Uml, X. Tan, Keng Siau, J. Erickson Aug 2007

Design Science Research On Systems Analysis And Design: The Case Of Uml, X. Tan, Keng Siau, J. Erickson

Research Collection School Of Computing and Information Systems

Design science in the IS discipline seeks to create artifacts that embody the ideas, practices, technical capabilities, and products required to efficiently accomplish the analysis, design, implementation, and use of information systems (Hevner et al 2006). SA&D research, being close to the design science paradigm, has suffered from a lack of appreciation from the behavioral science paradigm. To provide a paradigmatic foundation, we propose a conceptual framework for SA&D research. The framewor was developed based on several essays that systematically articulate the design science paradigm in the IS field. Using this framework, we reviewed some UML papers that appeared in …


Fault Tolerant Firewall Sandwiches, Stephen M. Goddard Aug 2007

Fault Tolerant Firewall Sandwiches, Stephen M. Goddard

School of Computing: Faculty Publications

Firewall sandwich configurations having improved levels of system availability as well as an application-space implementation of a firewall load balancer (FLB) which provides greater operational flexibility while reducing the need for custom hardware and/or operating system software. Also disclosed is a firewall capable of functionally replacing an FLB upon detecting a failure therein.


A Scalable Approach For Survivable Virtual Topology Routing In Optical Wdm Networks, Ajay Todimala, Byrav Ramamurthy Aug 2007

A Scalable Approach For Survivable Virtual Topology Routing In Optical Wdm Networks, Ajay Todimala, Byrav Ramamurthy

School of Computing: Faculty Publications

The survivable virtual topology routing problem is to route a virtual topology graph on a optical fiber physical topology such that the virtual topology remains connected when failures occur in the physical topology. In this work we study the problem of survivable virtual topology routing under single node/SRLG (Shared Risk Link Group) failure model. We prove that the survivable virtual topology routing problem under node/SRLG failures is NP-complete. We present an improved integer linear programming (ILP) formulation for computing the survivable routing of a virtual topology graph. However, ILP is not scalable when the network size scales more than a …


Interface Design For Handheld Mobile Devices, Peter Tarasewich, Jun Gong, Fiona Fui-Hoon Nah Aug 2007

Interface Design For Handheld Mobile Devices, Peter Tarasewich, Jun Gong, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

Mobile computing has attracted a lot of attention from both the industry and academia in recent years. While a number of mobile applications have been developed, there are no established guidelines on the design of mobile device interfaces. This paper presents our initial efforts to provide a set of practical design guidelines for mobile device interfaces.


Autoreducibility, Mitoticity, And Immunity, Christian Glaßer, Mitsunori Ogihara, A. Pavan, Alan L. Selman, Liyu Zhang Aug 2007

Autoreducibility, Mitoticity, And Immunity, Christian Glaßer, Mitsunori Ogihara, A. Pavan, Alan L. Selman, Liyu Zhang

Computer Science Faculty Publications

We show the following results regarding complete sets. • NP-complete sets and PSPACE-complete sets are polynomial-time many–one autoreducible.

• Complete sets of any level of PH, MODPH, or the Boolean hierarchy over NP are polynomial-time many–one autoreducible.

• EXP-complete sets are polynomial-time many–one mitotic.

• If there is a tally language in NP ∩ coNP − P , then, for every ϵ > 0 , NP-complete sets are not 2 n ( 1 + ϵ ) -immune.

These results solve several of the open questions raised by Buhrman and Torenvliet in their 1994 survey paper on the structure of complete sets.


A Lateral Symmetry Approach To Percentage-Based Hybrid Pattern (Php) Training, Sheng-Uei Guan, Kiruthika Ramanathan Aug 2007

A Lateral Symmetry Approach To Percentage-Based Hybrid Pattern (Php) Training, Sheng-Uei Guan, Kiruthika Ramanathan

Research Collection School Of Computing and Information Systems

In this paper, we investigate the application of lateral symmetry to supervised learning using genetic algorithms. The hypothesis is motivated by the presence of symmetry in the animal brain and by research results showing approximately equal task division between the two hemispheres of the brain. In this paper, each training pattern is considered a task. By applying the concept of lateral symmetry, we use global training (a typically right brained activity) to learn half the tasks and local training (a left brained activity) to learn the rest of the tasks. We verified the use of this Percentage-based Pattern (PHP) training …


Measuring Knowledge Sharing In Open Source Software Development Teams, Y. Long, Keng Siau, K. Howell Aug 2007

Measuring Knowledge Sharing In Open Source Software Development Teams, Y. Long, Keng Siau, K. Howell

Research Collection School Of Computing and Information Systems

The study provides an approach to measure the extent of knowledge sharing in Open Source Software (OSS) development in terms of two aspects: the quality of knowledge sharing which is indicated by the helpfulness of the messages, and the quantity of knowledge sharing which is indicated by the volume of the messages. The study developed a computer-aided content analysis program to assess the helpfulness of the messages based on a set of keywords and the length of the messages. The approach was applied to measure the extent of knowledge sharing of 150 OSS projects. The results further confirmed that the …


Theoretical And Practical Complexity Of Modeling Methods, John Erickson, Keng Siau Aug 2007

Theoretical And Practical Complexity Of Modeling Methods, John Erickson, Keng Siau

Research Collection School Of Computing and Information Systems

The estimation of theoretical and practical complexity of a system development method is discussed. Executable model capability allow developers to transform models developed during the Systems Analysis and Design portion of the systems development process into working applications. Systems are becoming more complex mostly because of influencing factors such as required and enhanced functionality, interoperability, and security. Other trends that impact the complexity of applications include systems such as enterprise resource planning, supply chain management, and customer relationship management. These types of systems are very large and complex and require close internal cooperation for the implementing organizations individually and also …


Mapping Better Business Strategies With Gis, Tin Seong Kam Aug 2007

Mapping Better Business Strategies With Gis, Tin Seong Kam

Research Collection School Of Computing and Information Systems

The value of location as a business measure is fast becoming an important consideration for organisations. GIS (Geographical Information Systems), with its capability to manage, display, analyse business information spatially, is emerging as a powerful location intelligence tool. In the US, Starbucks, Blockbuster, Hyundai, and thousands of other businesses use census data and GIS software to help them understand what types of people buy their products and services, and how to better market to these consumers. For example, McDonald’s in Japan uses a GIS system to overlay demographic information on maps to help identify promising new store sites. Singapore Management …


A Genetic Algorithm For Cellular Manufacturing Design And Layout, Xiaodan Wu, Chao-Hsien Chu, Yunfeng Wang, Weili Yan Aug 2007

A Genetic Algorithm For Cellular Manufacturing Design And Layout, Xiaodan Wu, Chao-Hsien Chu, Yunfeng Wang, Weili Yan

Research Collection School Of Computing and Information Systems

Cellular manufacturing (CM) is an approach that can be used to enhance both flexibility and efficiency in today’s small-to-medium lot production environment. The design of a CM system (CMS) often involves three major decisions: cell formation, group layout, and group schedule. Ideally, these decisions should be addressed simultaneously in order to obtain the best results. However, due to the complexity and NP-complete nature of each decision and the limitations of traditional approaches, most researchers have only addressed these decisions sequentially or independently. In this study, a hierarchical genetic algorithm is developed to simultaneously form manufacturing cells and determine the group …