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2009

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Articles 1201 - 1230 of 1345

Full-Text Articles in Computer Sciences

Computer-Aided Reasoning About Knowledge And Justifications, Natalia Novak Jan 2009

Computer-Aided Reasoning About Knowledge And Justifications, Natalia Novak

Dissertations, Theses, and Capstone Projects

In the first Chapter we compare two well-known type-based computer frameworks for computer aided logical reasoning and verification: MetaPRL and Coq. In particular, we implement in MetaPRL the Calculus of Inductive Constructions which is the theoretical base for Coq. This work has shown the common points of MetaPRL and Coq, and revealed their principal methodological differences. A possible application of this work is a possibility to perform re-validation in MetaPRL of the existing library of Coq proofs which could help to build more trust in the latter.

Chapter 2 is the main contribution of the dissertation. It contains the description …


Ontology-Based Business Process Customization For Composite Web Services, Qianhui (Althea) Liang, Xindong Wu, E. K. Park, T. Khoshgoftaar, C. Chi Jan 2009

Ontology-Based Business Process Customization For Composite Web Services, Qianhui (Althea) Liang, Xindong Wu, E. K. Park, T. Khoshgoftaar, C. Chi

Research Collection School Of Computing and Information Systems

A key goal of the Semantic Web is to shift social interaction patterns from a producer-centric paradigm to a consumer-centric one. Treating customers as the most valuable assets and making the business models work better for them are at the core of building successful consumer-centric business models. It follows that customizing business processes constitutes a major concern in the realm of a knowledge-pull-based human semantic Web. This paper conceptualizes the customization of service-based business processes leveraging the existing knowledge of Web services and business processes. We represent this conceptualization as a new Extensible Markup Language (XML) markup language Web Ontology …


Web Social Mining, Hady W. Lauw, Ee Peng Lim Jan 2009

Web Social Mining, Hady W. Lauw, Ee Peng Lim

Research Collection School Of Computing and Information Systems

No abstract provided.


Continuous Monitoring Of Spatial Queries, Kyriakos Mouratidis Jan 2009

Continuous Monitoring Of Spatial Queries, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

No abstract provided.


Efficient Valid Scope Computation For Location-Dependent Spatial Queries In Mobile And Wireless Environments, Ken C. K. Lee, Wang-Chien Lee, Hong Va Leong, Brandon Unger, Baihua Zheng Jan 2009

Efficient Valid Scope Computation For Location-Dependent Spatial Queries In Mobile And Wireless Environments, Ken C. K. Lee, Wang-Chien Lee, Hong Va Leong, Brandon Unger, Baihua Zheng

Research Collection School Of Computing and Information Systems

In mobile and wireless environments, mobile clients can access information with respect to their locations by submitting Location-Dependent Spatial Queries (LDSQs) to Location-Based Service (LBS) servers. Owing to scarce wireless channel bandwidth and limited client battery life, frequent LDSQ submission from clients must be avoided. Observing that LDSQs issued from similar client positions would normally return the same results, we explore the idea of valid scope, that represents a spatial area in which a set of LDSQs will retrieve exactly the same query results. With a valid scope derived and an LDSQ result cached at the client side, a client …


Offering Rss Feeds: Does It Help To Gain Competitive Advantage?, Dan Ma Jan 2009

Offering Rss Feeds: Does It Help To Gain Competitive Advantage?, Dan Ma

Research Collection School Of Computing and Information Systems

Nowadays, many Websites have adopted the really simple syndication (RSS) technology to deliver online content to visitors. In this paper, I build an analytical model to examine how the offering of RSS feeds impact the number of visitors, total traffic load, and profit of Websites in a competitive setting. I show that although RSS can always attract more visitors, it may reduce the Website's profit. Interestingly, in a competitive market there are cases that the RSS feeds hurt the offering Website but benefit the competing Website instead. The conditions under which these will happen are derived. I also study the …


Integrated Resource Allocation And Scheduling In Bidirectional Flow Shop With Multi-Machine And Cos Constraints, Hoong Chuin Lau, Zhengyi Zhao, Shuzhi Sam Ge Jan 2009

Integrated Resource Allocation And Scheduling In Bidirectional Flow Shop With Multi-Machine And Cos Constraints, Hoong Chuin Lau, Zhengyi Zhao, Shuzhi Sam Ge

Research Collection School Of Computing and Information Systems

An integer programming (IP) model is proposed for integrated resource allocation and operation scheduling for a multiple job-agents system. Each agent handles a specific job-list in a bidirectional flowshop. For the individual agent scheduling problem, a formulation is proposed in continuous time domain and compared with an IP formulation in discrete time domain. Of particular interest is the formulation of the machine utilization function-- both in continuous time and discrete time. Fast heuristic methods are proposed with the relaxation of the machine capacity. For the integrated resource allocation and scheduling problem, a linear programming relaxation approach is applied to solve …


Multiuser Private Queries Over Encrypted Databases, Yanjiang Yang, Feng Bao, Xuhua Ding, Robert H. Deng Jan 2009

Multiuser Private Queries Over Encrypted Databases, Yanjiang Yang, Feng Bao, Xuhua Ding, Robert H. Deng

Research Collection School Of Computing and Information Systems

Searchable encryption schemes allow users to perform keyword-based searches on an encrypted database. Almost all existing such schemes only consider the scenario where a single user acts as both the data owner and the querier. However, most databases in practice do not just serve one user; instead, they support search and write operations by multiple users. In this paper, we systematically study searchable encryption in a practical multiuser setting. Our results include a set of security notions for multiuser searchable encryption as well as a construction which is provably secure under the newly introduced security notions. We also discuss how …


Automatic Video Classification, Don Jayakody Jan 2009

Automatic Video Classification, Don Jayakody

Master's Projects

Within the past few years video usage has grown in a multi-fold fashion. One of the major reasons for this explosive video growth is the rising Internet bandwidth speeds. As of today, a significant human effort is needed to categorize these video data files. A successful automatic video classification method can substantially help to reduce the growing amount of cluttered video data on the Internet. This research project is based on finding a successful model for video classification. We have utilized various schemes of visual and audio data analysis methods to build a successful classification model. As far as the …


Evaluations And Enhancements In 802.11n Wlans – Error-Sensitive Adaptive Frame Aggregation, Ken Chan Jan 2009

Evaluations And Enhancements In 802.11n Wlans – Error-Sensitive Adaptive Frame Aggregation, Ken Chan

Master's Projects

IEEE 802.11n is a developing next-generation standard for wireless local area network (LAN). Seamless multimedia traffic connection will become possible with the 802.11n improvement in the Physical and MAC layer. The new 802.11n frame aggregation technique is particularly important for enhancing MAC layer efficiency under high speed wireless LAN. Although the frame aggregation can increase the efficiency in the MAC layer, it does not provide good performance in high BER channels when using large frame aggregation size. An Optimal Frame Aggregation (OFA) technique for AMSDU frame under different BERs in 802.11n WLANs was proposed. However, the suggested algorithm does not …


Versatile Extensible Security System For Mobile Ad Hoc Networks, Jung Chang Jan 2009

Versatile Extensible Security System For Mobile Ad Hoc Networks, Jung Chang

Master's Projects

Mobile Ad hoc Network (MANET) is becoming more and more popular in scientific, government, and general applications, but security system for MANET is still at infant stage. Currently, there are not many security systems that provide extensive security coverage for MANET. Moreover, most of these security systems assume nodes have infinite computation power and energy; an assumption that is not true for many mobiles. Versatile and Extensible System (VESS) is a powerful and versatile general-purpose security suite that comprises of modified versions of existing encryption and authentication schemes. VESS uses a simple and network-efficient but still reliable authentication scheme. The …


Is Four File Chess A Draw?, Michael Karbushev Jan 2009

Is Four File Chess A Draw?, Michael Karbushev

Master's Projects

In this work, we prove that in the game of FOUR FILE Chess, White has at least a Draw. FOUR FILE is a chess variant proposed by John Selfridge, in which only the `a', `c', `e', and `g' les are used. All chess rules are as usual, except that all moves must end on one of these les, and the game starts with the other four les vacant. Here, we prove that the White has at least a draw, by showing that White has a strategy to avoid a loss. We also show that Black can avoid a loss for …


Knowledge Engineering From Data Perspective: Granular Computing Approach, Rushin Barot Jan 2009

Knowledge Engineering From Data Perspective: Granular Computing Approach, Rushin Barot

Master's Projects

The concept of rough set theory is a mathematical approach to uncertainly and vagueness in data analysis, introduced by Zdzislaw Pawlak in 1980s. Rough set theory assumes the underlying structure of knowledge is a partition. We have extended Pawlak’s concept of knowledge to coverings. We have taken a soft approach regarding any generalized subset as a basic knowledge. We regard a covering as basic knowledge from which the theory of knowledge approximations and learning, knowledge dependency and reduct are developed.


Priority Based Power Management And Reduced Downtime In Data Centers, Barath Kuppuswamy Jan 2009

Priority Based Power Management And Reduced Downtime In Data Centers, Barath Kuppuswamy

Master's Projects

The project deals successfully with software that performs priority based power management and reduced downtime for virtual machines running in data centers. The software deals with power management only at the processor level. The software automatically performs load distribution among servers in data centers to save power. In addition, the software also lets administrator of data centers to mark certain virtual machines, which run user applications, as critical to minimize downtimes for these virtual machines. The software reveals that energy consumption can be minimized while maintaining high runtime availability for the mission critical applications. The software operates in Green mode …


Removing The Digital Divide For Senior Web Users, Chiu Luk Jan 2009

Removing The Digital Divide For Senior Web Users, Chiu Luk

Master's Projects

It is hard for the elderly to use the internet to find the resource they want. Usually help is needed for them to complete the task on the technology things. The main reason for this project is to research ideas on encourage senior people to make use of the web to locate helps they want, such as finding volunteers and professional helps. The scope of this project is to develop a new way of web access and content presentation methodologies that let senior people getting help from volunteers and various service providers more easily that incorporates social networking technology e.g. …


Jor: A Journal-Guided Reconstruction Optimization For Raid-Structured Storage Systems, Suzhen Wu, Dan Feng, Hong Jiang, Bo Mao, Lingfang Zeng, Jianxi Chen Jan 2009

Jor: A Journal-Guided Reconstruction Optimization For Raid-Structured Storage Systems, Suzhen Wu, Dan Feng, Hong Jiang, Bo Mao, Lingfang Zeng, Jianxi Chen

School of Computing: Conference and Workshop Papers

This paper proposes a simple and practical RAID reconstruction optimization scheme, called JOurnal-guided Reconstruction (JOR). JOR exploits the fact that significant portions of data blocks in typical disk arrays are unused. JOR monitors the storage space utilization status at the block level to guide the reconstruction process so that only failed data on the used stripes is recovered to the spare disk. In JOR, data consistency is ensured by the requirement that all blocks in a disk array be initialized to zero (written with value zero) during synchronization while all blocks in the spare disk also be initialized to zero …


An Adaptive Steganography Scheme For Voice Over Ip, Hui Tian, Ke Zhou, Hong Jiang, Yongfeng Huang, Jin Liu, Dan Feng Jan 2009

An Adaptive Steganography Scheme For Voice Over Ip, Hui Tian, Ke Zhou, Hong Jiang, Yongfeng Huang, Jin Liu, Dan Feng

School of Computing: Conference and Workshop Papers

This paper presents an adaptive steganography scheme for Voice over IP (VoIP). Differing from existing steganography techniques for VoIP, this scheme enhances the embedding transparency by taking into account the similarity between Least Significant Bits (LSBs) and embedded messages. Moreover, we introduce the notion of Partial Similarity Value (PSV). By properly setting the threshold PSV, we can adaptively balance the embedding transparency and capacity. We evaluate the effectiveness of this scheme with G.729a as the codec of the cover speech in StegTalk, a covert communication system based on VoIP. The experimental results demonstrate that our technique provides better performance than …


An Adaptive Steganography Scheme For Voice Over Ip, Hui Tian, Ke Zhou, Hong Jiang, Yongfeng Huang, Jin Liu, Dan Feng Jan 2009

An Adaptive Steganography Scheme For Voice Over Ip, Hui Tian, Ke Zhou, Hong Jiang, Yongfeng Huang, Jin Liu, Dan Feng

School of Computing: Conference and Workshop Papers

This paper presents an adaptive steganography scheme for Voice over IP (VoIP). Differing from existing steganography techniques for VoIP, this scheme enhances the embedding transparency by taking into account the similarity between Least Significant Bits (LSBs) and embedded messages. Moreover, we introduce the notion of Partial Similarity Value (PSV). By properly setting the threshold PSV, we can adaptively balance the embedding transparency and capacity. We evaluate the effectiveness of this scheme with G.729a as the codec of the cover speech in StegTalk, a covert communication system based on VoIP. The experimental results demonstrate that our technique provides better performance than …


Joint Computing And Network Resource Scheduling In A Lambda Grid Network, Vaidhehi Lakshmiraman, Byrav Ramamurthy Jan 2009

Joint Computing And Network Resource Scheduling In A Lambda Grid Network, Vaidhehi Lakshmiraman, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Data-intensive Grid applications require huge data transfers between grid computing nodes. These computing nodes, where computing jobs are executed, are usually geographically separated. A grid network that employs optical wavelength division multiplexing (WDM) technology and optical switches to interconnect computing resources with dynamically provisioned multi-gigabit rate bandwidth lightpath is called a Lambda Grid network. A computing task may be executed on any one of several computing nodes which possesses the necessary resources. In order to reflect the reality in job scheduling, allocation of network resources for data transfer should be taken into consideration. However, few scheduling methods consider the communication …


A Cooperative Scheme For Dynamic Window Resizing In P2p Live Streaming, Zhipeng Ouyang, Lisong Xu, Byrav Ramamurthy Jan 2009

A Cooperative Scheme For Dynamic Window Resizing In P2p Live Streaming, Zhipeng Ouyang, Lisong Xu, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Due to their widespread popularity, Peer-to-Peer (P2P) live streaming systems have become a great challenge for Internet Service Providers (ISPs) as they consume huge amount of Internet bandwidth. By observing that different users may watch a channel with different window sizes, we propose a cooperative scheme called Partial Participation Scheme (PPS) in which different peers request a video stream at different rates based on their window sizes, and a subset of peers viewing the video stream using a small window work as helpers to forward extra data to help other peers using a large window. By reducing streaming rate received …


Optimal Segment Size For Fixed-Sized Segment Protection In Wavelength-Routed Optical Networks, Raghunath Tewari, Byrav Ramamurthy Jan 2009

Optimal Segment Size For Fixed-Sized Segment Protection In Wavelength-Routed Optical Networks, Raghunath Tewari, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Protecting a network against link failures is a major challenge faced by network operators. The protection scheme has to address two important objectives - fast recovery and minimizing the amount of backup resources needed. Every protection algorithm is a tradeoff between these two objectives.

In this paper, we study the problem of segment protection. In particular, we investigate what is the optimal segment size that obtains the best tradeoff between the time taken for recovery and minimizing the bandwidth used by the backup segments. We focus on the uniform fixed-length segment protection method, where each primary path is divided into …


A Flexible Divide-And-Conquer Protocol For Multi-View Peer-To-Peer Live Streaming, Miao Wang, Lisong Xu, Byrav Ramamurthy Jan 2009

A Flexible Divide-And-Conquer Protocol For Multi-View Peer-To-Peer Live Streaming, Miao Wang, Lisong Xu, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Multi-view peer-to-peer (P2P) live streaming systems have recently emerged, where a user can simultaneously watch multiple channels. Previous work on multi-view P2P streaming solves the fundamental inter-channel bandwidth competition problem at the individual peer level, and thus can be used with very limited types of streaming protocols. In this paper, we propose a new protocol for multi-view P2P streaming, called Divide-and-Conquer (DAC), which efficiently solves the inter-channel bandwidth competition problem using a divide-and-conquer strategy at the channel level, and thus is flexible to work with various streaming protocols. This makes DAC more suitable for upgrading current single-view P2P live streaming …


Error Control In Wireless Sensor Networks: A Cross Layer Analysis, Mehmet C. Vuran, Ian F. Akyildiz Jan 2009

Error Control In Wireless Sensor Networks: A Cross Layer Analysis, Mehmet C. Vuran, Ian F. Akyildiz

School of Computing: Faculty Publications

Error control is of significant importance for Wireless Sensor Networks (WSNs) because of their severe energy constraints and the low power communication requirements. In this paper, a cross-layer methodology for the analysis of error control schemes in WSNs is presented such that the effects of multi-hop routing and the broadcast nature of the wireless channel are investigated. More specifically, the cross-layer effects of routing, medium access, and physical layers are considered. This analysis enables a comprehensive comparison of forward error correction (FEC) codes, automatic repeat request (ARQ), and hybrid ARQ schemes in WSNs. The validation results show that the developed …


Smart Templates For Peak Pattern Matching With Comprehensive Two-Dimensional Liquid Chromatography, Stephen E. Reichenbach, Peter W. Carr, Dwight R. Stoll, Qingping Tao Jan 2009

Smart Templates For Peak Pattern Matching With Comprehensive Two-Dimensional Liquid Chromatography, Stephen E. Reichenbach, Peter W. Carr, Dwight R. Stoll, Qingping Tao

School of Computing: Faculty Publications

Comprehensive two-dimensional liquid chromatography (LC × LC) generates information-rich but complex peak patterns that require automated processing for rapid chemical identification and classification. This paper describes a powerful approach and specific methods for peak pattern matching to identify and classify constituent peaks in data from LC × LC and other multidimensional chemical separations. The approach records a prototypical pattern of peaks with retention times and associated metadata, such as chemical identities and classes, in a template. Then, the template pattern is matched to the detected peaks in subsequent data and the metadata are copied from the template to identify and …


Directed Test Suite Augmentation, Zhihong Xu, Gregg Rothermel Jan 2009

Directed Test Suite Augmentation, Zhihong Xu, Gregg Rothermel

School of Computing: Conference and Workshop Papers

As software evolves, engineers use regression testing to evaluate its fitness for release. Such testing typically begins with existing test cases, and many techniques have been proposed for reusing these cost-effectively. After reusing test cases, however, it is also important to consider code or behavior that has not been exercised by existing test cases and generate new test cases to validate these. This process is known as test suite augmentation. In this paper we present a directed test suite augmentation technique, that utilizes results from reuse of existing test cases together with an incremental concolic testing algorithm to augment …


Technical Reports (2004 - 2009) Jan 2009

Technical Reports (2004 - 2009)

School of Computing: Technical Reports

Authors of Technical Reports (2005-2009):
Choueiry, Berthe
Cohen, Myra
Deogun, Jitender
Dwyer, Matthew
Elbaum, Sebastian
Goddard, Steve
Henninger, Scott
Jiang, Hong
Lu, Ying
Ramamurthy, Byrav
Rothermel, Gregg
Scott, Stephen
Seth, Sharad
Soh, Leen-Kiat
Srisa-an, Witty
Swanson, David
Variyam, Vinodchandran
Wang, Jun
Xu, Lisong


Cross-Layer Analysis Of The End-To-End Delay Distribution In Wireless Sensor Networks, Yunbo Wang, Mehmet C. Vuran, Steve Goddard Jan 2009

Cross-Layer Analysis Of The End-To-End Delay Distribution In Wireless Sensor Networks, Yunbo Wang, Mehmet C. Vuran, Steve Goddard

School of Computing: Conference and Workshop Papers

Emerging applications of wireless sensor networks (WSNs) require real-time quality of service (QoS) guarantees to be provided by the network. However, designing real-time scheduling and communication solutions for these networks is challenging since the characteristics of QoS metrics in WSNs are not well known yet. Due to the nature of wireless connectivity, it is infeasible to satisfy worst-case QoS requirements in WSNs. Instead, probabilistic QoS guarantees should be provided, which requires the definition of probabilistic QoS metrics. To provide an analytical tool for the development of real-time solutions, in this paper, the distribution of end-to-end delay in multi-hop WSNs is …


Using Hadoop As A Grid Storage Element, Brian Bockelman Jan 2009

Using Hadoop As A Grid Storage Element, Brian Bockelman

School of Computing: Conference and Workshop Papers

Hadoop is an open-source data processing framework that includes a scalable, fault- tolerant distributed file system, HDFS. Although HDFS was designed to work in conjunction with Hadoop's job scheduler, we have re-purposed it to serve as a grid storage element by adding GridFTP and SRM servers. We have tested the system thoroughly in order to understand its scalability and fault tolerance. The turn-on of the Large Hadron Collider (LHC) in 2009 poses a significant data management and storage challenge; we have been working to introduce HDFS as a solution for data storage for one LHC experiment, the Compact Muon Solenoid …


A Hybrid Test Architecture To Reduce Test Application Time In Full Scan Sequential Circuits, Priyankar Ghosh, Srobona Mitra, Indranil Sengupta, Bhargab B. Bhattacharya, Sharad C. Seth Jan 2009

A Hybrid Test Architecture To Reduce Test Application Time In Full Scan Sequential Circuits, Priyankar Ghosh, Srobona Mitra, Indranil Sengupta, Bhargab B. Bhattacharya, Sharad C. Seth

School of Computing: Conference and Workshop Papers

Abstract—Full scan based design technique is widely used to alleviate the complexity of test generation for sequential circuits. However, this approach leads to substantial increase in test application time, because of serial loading of vectors. Although BIST based approaches offer faster testing, they usually suffer from low fault coverage. In this paper, we propose a hybrid test architecture, which achieves significant reduction in test application time. The test suite consists of: (i) some external deterministic test vectors to be scanned in, and (ii) internally generated responses of the CUT to be re-applied as tests iteratively, in functional (non-scan) mode. The …


Chaos And Uncertainty, M. Thulasidas Jan 2009

Chaos And Uncertainty, M. Thulasidas

Research Collection School Of Computing and Information Systems

The end of 2008 in the finance industry can be summarized in two words – chaos and uncertainty. The subprime crisis, where everybody lost; the dizzying commodity price movements; the pink slip syndrome; the spectacular bank busts; and the gargantuan bail-outs all vouch for it.