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Articles 7891 - 7920 of 9003

Full-Text Articles in Computer Sciences

Multi-View Ear Recognition Based On B-Spline Pose Manifold Construction, Zhiyuan Zhang, Heng Liu Jun 2008

Multi-View Ear Recognition Based On B-Spline Pose Manifold Construction, Zhiyuan Zhang, Heng Liu

Research Collection School Of Computing and Information Systems

In this work, multi-view ear recognition problems are examined in detail. A new multi-view ear recognition approach based on B-Spline pose manifold construction in discriminative projection space which is formed by null kernel discriminant analysis (NKDA) feature extraction is presented. Many experiments and comparisons are provided to show the effectiveness of our multi-view ear recognition approach.

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Information-Theory Based Optimal Location Management Schemes For Integrated Multi-System Wireless Networks, Archan Misra, Abhishek Roy, Sajal K. Das Jun 2008

Information-Theory Based Optimal Location Management Schemes For Integrated Multi-System Wireless Networks, Archan Misra, Abhishek Roy, Sajal K. Das

Research Collection School Of Computing and Information Systems

In a multisystem environment where a mobile node can utilize multiple interfaces and simultaneously connect to multiple providers, new opportunities exist for efficient location management strategies spanning heterogeneous cellular wireless networks. In this paper, an integrated framework is developed for location management in such a multi-system, fourth generation (4 G) wireless networks. This information-theoretic framework allows each individual sub-system to operate fairly independently, and does not require the knowledge of individual sub-network topologies. An efficient location management in such a loosely coupled network is designed by having a mobile node view its movement as a vector-valued sequence, and then transmit …

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Probabilistically Reliable On-Demand Multicast In Wireless Mesh Networks, Xin Zhao, Chun Tung Chou, Jun Guo, Sanjay Jha, Archan Misra Jun 2008

Probabilistically Reliable On-Demand Multicast In Wireless Mesh Networks, Xin Zhao, Chun Tung Chou, Jun Guo, Sanjay Jha, Archan Misra

Research Collection School Of Computing and Information Systems

This paper studies probabilistically reliable multicast in wireless mesh networks (WMNs), utilizing MAC layer re-transmission and wireless broadcast advantage to improve both the multicast throughput and the delivery rate. We first present a new multicast routing metric which we call the expected multicast transmissions (EMT). EMT captures the effect of link packet delivery ratio, MAC layer retransmission and wireless broadcast advantage at the same time. The EMT of a MAC layer multicast transmission is the expected number of data transmissions (including retransmissions) required for a packet to reach all the recipients. The EMT of a multicast tree is the sum …

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Work Dispersion, Process-Based Learning And Offshore Software Development Performance, Narayanasamy Ramasubbu, Sunil Mithas, M. S. Krishnan, Chris Kemerer Jun 2008

Work Dispersion, Process-Based Learning And Offshore Software Development Performance, Narayanasamy Ramasubbu, Sunil Mithas, M. S. Krishnan, Chris Kemerer

Research Collection School Of Computing and Information Systems

In this paper we develop a learning-mediated model of offshore software project productivity and quality to examine whether widely adopted structured software processes are effective in mitigating the negative effects of work dispersion in offshore software development. We explicate how the key process areas of the capability maturity model (CMM) can be utilized as a platform to launch learning routines in offshore software development and thereby explain why some offshore software development process improvement initiatives are more effective than others. We validate our learning-mediated model of offshore software project performance by utilizing data collected from 42 offshore software projects of …

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Semi-Supervised Svm Batch Mode Active Learning For Image Retrieval, Steven Hoi, Rong Jin, Jianke Zhu, Michael R. Lyu Jun 2008

Semi-Supervised Svm Batch Mode Active Learning For Image Retrieval, Steven Hoi, Rong Jin, Jianke Zhu, Michael R. Lyu

Research Collection School Of Computing and Information Systems

Active learning has been shown as a key technique for improving content-based image retrieval (CBIR) performance. Among various methods, support vector machine (SVM) active learning is popular for its application to relevance feedback in CBIR. However, the regular SVM active learning has two main drawbacks when used for relevance feedback. First, SVM often suffers from learning with a small number of labeled examples, which is the case in relevance feedback. Second, SVM active learning usually does not take into account the redundancy among examples, and therefore could select multiple examples in relevance feedback that are similar (or even identical) to …

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Seemon: Scalable And Energy-Efficient Context Monitoring Framework For Sensor-Rich Mobile Environments, Seungwoo Kang, Jinwon Lee, Hyukjae Jang, Hyonik Lee, Youngki Lee, Souneil Park, Taiwoo Park, Junehwa Song Jun 2008

Seemon: Scalable And Energy-Efficient Context Monitoring Framework For Sensor-Rich Mobile Environments, Seungwoo Kang, Jinwon Lee, Hyukjae Jang, Hyonik Lee, Youngki Lee, Souneil Park, Taiwoo Park, Junehwa Song

Research Collection School Of Computing and Information Systems

Proactively providing services to mobile individuals is essential for emerging ubiquitous applications. The major challenge in providing users with proactive services lies in continuously monitoring their contexts based on numerous sensors. The context monitoring with rich sensors imposes heavy workloads on mobile devices with limited computing and battery power. We present SeeMon, a scalable and energy-efficient context monitoring framework for sensor-rich, resource-limited mobile environments. Running on a personal mobile device, SeeMon effectively performs context monitoring involving numerous sensors and applications. On top of SeeMon, multiple applications on the device can proactively understand users' contexts and react appropriately. This paper proposes …

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Visual Analytics For Supporting Entity Relationship Discovery On Text Data, Hanbo Dai, Ee Peng Lim, Hady W. Lauw, Hwee Hwa Pang Jun 2008

Visual Analytics For Supporting Entity Relationship Discovery On Text Data, Hanbo Dai, Ee Peng Lim, Hady W. Lauw, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

To conduct content analysis over text data, one may look out for important named objects and entities that refer to real world instances, synthesizing them into knowledge relevant to a given information seeking task. In this paper, we introduce a visual analytics tool called ER-Explorer to support such an analysis task. ER-Explorer consists of a data model known as TUBE and a set of data manipulation operations specially designed for examining entities and relationships in text. As part of TUBE, a set of interestingness measures is defined to help exploring entities and their relationships. We illustrate the use of ER-Explorer …

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Capacity Constrained Assignment In Spatial Databases, Hou U Leong, Man Lung Yiu, Kyriakos Mouratidis, Nikos Mamoulis Jun 2008

Capacity Constrained Assignment In Spatial Databases, Hou U Leong, Man Lung Yiu, Kyriakos Mouratidis, Nikos Mamoulis

Research Collection School Of Computing and Information Systems

Given a point set P of customers (e.g., WiFi receivers) and a point set Q of service providers (e.g., wireless access points), where each q 2 Q has a capacity q.k, the capacity constrained assignment (CCA) is a matching M Q × P such that (i) each point q 2 Q (p 2 P) appears at most k times (at most nce) in M, (ii) the size of M is maximized (i.e., it comprises min{|P|,P q2Q q.k} pairs), and (iii) the total assignment cost (i.e., the sum of Euclidean distances within all pairs) is minimized. Thus, the CCA problem is …

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An Office Survival Guide, M. Thulasidas Jun 2008

An Office Survival Guide, M. Thulasidas

Research Collection School Of Computing and Information Systems

In the unforgiving, dog-eat-dog corporate jungle, when you find yourself in a new corporate setting, you need to be sure of the welcome. More importantly, you need to prove yourself worthy of it.

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Traceable And Retrievable Identity-Based Encryption, Man Ho Au, Qiong Huang, Joseph K. Liu, Willy Susilo, Duncan S. Wong, Guomin Yang Jun 2008

Traceable And Retrievable Identity-Based Encryption, Man Ho Au, Qiong Huang, Joseph K. Liu, Willy Susilo, Duncan S. Wong, Guomin Yang

Research Collection School Of Computing and Information Systems

Very recently, the concept of Traceable Identity-based Encryption (IBE) scheme (or Accountable Authority Identity based Encryption scheme) was introduced in Crypto 2007. This concept enables some mechanisms to reduce the trust of a private key generator (PKG) in an IBE system. The aim of this paper is threefold. First, we discuss some subtleties in the first traceable IBE scheme in the Crypto 2007 paper. Second, we present an extension to this work by having the PKG’s master secret key retrieved automatically if more than one user secret key are released. This way, the user can produce a concrete proof of …

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Measuring Novelty And Redundancy With Multiple Modalities In Cross-Lingual Broadcast News, Xiao Wu, Alexander G. Hauptmann, Chong-Wah Ngo Jun 2008

Measuring Novelty And Redundancy With Multiple Modalities In Cross-Lingual Broadcast News, Xiao Wu, Alexander G. Hauptmann, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

News videos from different channels, languages are broadcast everyday, which provide abundant information for users. To effectively search, retrieve, browse and track news stories, news story similarity plays a critical role in assessing the novelty and redundancy among news stories. In this paper, we explore different measures of novelty and redundancy detection for cross-lingual news stories. A news story is represented by multimodal features which include a sequence of keyframes in the visual track, and a set of words and named entities extracted from speech transcript in the audio track. Vector space models and language models on individual features (text, …

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An Experimental Study On U-Commerce Adoption: Impact Of Personalization And Privacy Concerns, H. Sheng, Fiona Fui-Hoon Nah, Keng Siau Jun 2008

An Experimental Study On U-Commerce Adoption: Impact Of Personalization And Privacy Concerns, H. Sheng, Fiona Fui-Hoon Nah, Keng Siau

Research Collection School Of Computing and Information Systems

Ubiquitous commerce (u-commerce) represents “anytime, anywhere” commerce. U-commerce can provide a high level of personalization, which can bring significant benefits to customers. However, privacy is a major concern to customers and an obstacle to the adoption of u-commerce. This research examines how personalization and context can impact customers’ privacy concerns as well as intention to adopt u-commerce applications. As u-commerce is new and emerging, we used the scenario-based approach to operationalize personalization and context in an experimental study. The experimental results show that the effects of personalization on customers’ privacy concerns and adoption intention are situation dependent.

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Utility-Based Adaptation In Mission-Oriented Wireless Sensor Networks, Sharanya Eswaran, Archan Misra, Thomas La Porta Jun 2008

Utility-Based Adaptation In Mission-Oriented Wireless Sensor Networks, Sharanya Eswaran, Archan Misra, Thomas La Porta

Research Collection School Of Computing and Information Systems

This paper extends the distributed network utility maximization (NUM) framework to consider the case of resource sharing by multiple competing missions in a military-centric wireless sensor network (WSN) environment. Prior work on NUM-based optimization has considered unicast flows with sender-based utilities in either wireline or wireless networks. We extend the NUM framework to consider three key new features observed in mission-centric WSN environments: i) the definition of an individual mission's utility as a joint function of data from multiple sensor sources ii) the consumption of each senders (sensor) data by multiple receivers (missions) and iii) the multicast-tree based dissemination of …

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Localized Minimum-Latency Broadcasting In Multi-Radio Multi-Rate Wireless Mesh Networks, Junaid Qadir, Chun Tung Chou, Archan Misra, Joo Ghee Lim Jun 2008

Localized Minimum-Latency Broadcasting In Multi-Radio Multi-Rate Wireless Mesh Networks, Junaid Qadir, Chun Tung Chou, Archan Misra, Joo Ghee Lim

Research Collection School Of Computing and Information Systems

We address the problem of minimizing the worst-case broadcast delay in ldquomulti-radio multi-channel multi-rate wireless mesh networksrdquo (MR2-MC WMN) in a distributed and localized fashion. Efficient broadcasting in such networks is especially challenging due to the desirability of exploiting the ldquowireless broadcast advantagerdquo (WBA), the interface-diversity, the channel-diversity and the rate-diversity offered by these networks. We propose a framework that calculates a set of forwarding nodes and transmission rate at these forwarding nodes irrespective of the broadcast source. Thereafter, a forwarding tree is constructed taking into consideration the source of broadcast. Our broadcasting algorithms are distributed and utilize locally available …

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Advances And Challenges For Scalable Provenance In Stream Processing Systems, Archan Misra, Marion Blount, Anastasios Kementsietsidis, Daby Sow, Min Wang Jun 2008

Advances And Challenges For Scalable Provenance In Stream Processing Systems, Archan Misra, Marion Blount, Anastasios Kementsietsidis, Daby Sow, Min Wang

Research Collection School Of Computing and Information Systems

While data provenance is a well-studied topic in both database and workflow systems, its support within stream processing systems presents a new set of challenges. Part of the challenge is the high stream event rate and the low processing latency requirements imposed by many streaming applications. For example, emerging streaming applications in healthcare or finance call for data provenance, as illustrated in the Century stream processing infrastructure that we are building for supporting online healthcare analytics. At anytime, given an output data element (e.g., a medical alert) generated by Century, the system must be able to retrieve the input and …

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Electric Elves: What Went Wrong And Why, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Reddy Varakantham, Paul Scerri, David V. Pynadath Jun 2008

Electric Elves: What Went Wrong And Why, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Reddy Varakantham, Paul Scerri, David V. Pynadath

Research Collection School Of Computing and Information Systems

Software personal assistants continue to be a topic of significant research interest. This article outlines some of the important lessons learned from a successfully-deployed team of personal assistant agents (Electric Elves) in an office environment. In the Electric Elves project, a team of almost a dozen personal assistant agents were continually active for seven months. Each elf (agent) represented one person and assisted in daily activities in an actual office environment. This project led to several important observations about privacy, adjustable autonomy, and social norms in office environments. In addition to outlining some of the key lessons learned we outline …

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Platform Competition In Digital Systems: Architectural Control And Value Migration, C. Jason Woodard May 2008

Platform Competition In Digital Systems: Architectural Control And Value Migration, C. Jason Woodard

Research Collection School Of Computing and Information Systems

Digital systems give rise to complex layered architectures in which products at one layer serve as platforms for applications and services in adjacent layers. Platform owners face a difficult balancing act. On one hand, they need to make their platforms attractive to potential complementors by mitigating the threat of architectural lock-in. On the other hand, platform owners must be careful not to give away too much too soon, or risk being unable to recoup their own investments. This paper presents an agent-based model that explores this tension at both the firm and industry levels. Computational experiments show that boundedly rational …

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Measuring Soa Success, J. Erickson, Keng Siau May 2008

Measuring Soa Success, J. Erickson, Keng Siau

Research Collection School Of Computing and Information Systems

Service-oriented architecture (SOA), web services, and service-oriented computing (SOC) have become prominent topics in the business world. Many companies are either implementing, considering, or have already implemented SOA projects, web services initiatives, or SOC adoption. A critical question for organizations is how to measure SOA success. Is return on investment (ROI) a suitable metric for evaluating SOA projects? What about intangible factors such as comparative advantage or competitive necessity? Additionally, considerations like agility, nimbleness, and responsiveness play a significant role. This research investigates various factors for measuring project success and employs a Delphi study to gather insights from a panel …

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Architectural Control Points, C. Jason Woodard May 2008

Architectural Control Points, C. Jason Woodard

Research Collection School Of Computing and Information Systems

System designers and technology strategists have long recognized the concept of an architectural control point as a way to identify parts of a system that have particular strategic importance. Despite the vast body of work on system architecture in the engineering design literature, however, few authors have attempted to define architectural control points or study them systematically. Moreover, some industry participants have questioned whether architectural control is still a valuable or achievable goal in an era of increasingly open standards. This paper offers tentative definitions of architectural control, architectural control points, and architectural strategy. In a longer version of the …

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A Verification System For Timed Interval Calculus, Chunqing Chen, Jin Song Dong, Jun Sun May 2008

A Verification System For Timed Interval Calculus, Chunqing Chen, Jin Song Dong, Jun Sun

Research Collection School Of Computing and Information Systems

Timed Interval Calculus (TIC) is a highly expressive set-based notation for specifying and reasoning about embedded real-time systems. However, it lacks mechanical proving support, as its verification usually involves infinite time intervals and continuous dynamics. In this paper, we develop a system based on a generic theorem prover, Prototype Verification System (PVS), to assist formal verification of TIC at a high grade of automation. TIC semantics has been constructed by the PVS typed higher-order logic. Based on the encoding, we have checked all TIC reasoning rules and discovered subtle flaws. A translator has been implemented in Java to automatically transform …

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Verifying Completeness Of Relational Query Answers From Online Servers, Hwee Hwa Pang, Kian-Lee Tan May 2008

Verifying Completeness Of Relational Query Answers From Online Servers, Hwee Hwa Pang, Kian-Lee Tan

Research Collection School Of Computing and Information Systems

The number of successful attacks on the Internet shows that it is very difficult to guarantee the security of online servers over extended periods of time. A breached server that is not detected in time may return incorrect query answers to users. In this article, we introduce authentication schemes for users to verify that their query answers from an online server are complete (i.e., no qualifying tuples are omitted) and authentic (i.e., all the result values are legitimate). We introduce a scheme that supports range selection, projection as well as primary key-foreign key join queries on relational databases. We also …

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A Dynamic Trust Management Scheme To Mitigate Malware Proliferation In P2p Networks, Xuhua Ding, Wei Yu, Ying Pan May 2008

A Dynamic Trust Management Scheme To Mitigate Malware Proliferation In P2p Networks, Xuhua Ding, Wei Yu, Ying Pan

Research Collection School Of Computing and Information Systems

The surge of peer-to-peer (P2P) networks consisting of thousands of of hosts makes them a breeding ground for malware proliferation. Although some existing studies have shown that malware proliferation can pose significant threats to P2P networks, defending against such an attack is largely an open problem. This paper aims to develop the countermeasure that can effectively mitigate the malware proliferation while preserving P2P networks' performance. To this end, we propose a dynamic trust management scheme based upon localized trust evaluation and alert propagation which prevents innocent peers from downloading files from infected peers. Our analysis and experimental results show that …

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Stress Test, M. Thulasidas May 2008

Stress Test, M. Thulasidas

Research Collection School Of Computing and Information Systems

Ultimately, the risk factors that create stress in professional life do not generate any reward

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Scalable Detection Of Semantic Clones, Mark Gabel, Lingxiao Jiang, Zhendong Su May 2008

Scalable Detection Of Semantic Clones, Mark Gabel, Lingxiao Jiang, Zhendong Su

Research Collection School Of Computing and Information Systems

Several techniques have been developed for identifying similar code fragments in programs. These similar fragments, referred to as code clones, can be used to identify redundant code, locate bugs, or gain insight into program design. Existing scalable approaches to clone detection are limited to finding program fragments that are similar only in their contiguous syntax. Other, semantics-based approaches are more resilient to differences in syntax, such as reordered statements, related statements interleaved with other unrelated statements, or the use of semantically equivalent control structures. However, none of these techniques have scaled to real world code bases. These approaches capture semantic …

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A Scalable Approach To Multi-Style Architectural Modeling And Verification, Stephen Wong, Jing Sun, Ian Warren, Jun Sun Apr 2008

A Scalable Approach To Multi-Style Architectural Modeling And Verification, Stephen Wong, Jing Sun, Ian Warren, Jun Sun

Research Collection School Of Computing and Information Systems

Software Architecture represents the high level description of a system in terms of components, external properties and communication. Despite its importance in the software engineering process, the lack of formal description and verification support limits the value of developing architectural models. Automated formal engineering methods can provide an effective means to precisely describe and rigorously verify intended structures and behaviors of software systems. In this paper, we present an approach to support the design and verification of software architectural models using the Alloy analyzer. Based on our earlier work, we propose a fundamental library for specifying system structures in terms …

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A Formal Model Of Semantic Web Service Ontology (Wsmo) Execution, Hai H. Wang, Nick Gibbins, Terry R. Payne, Ahmed Saleh, Jun Sun Apr 2008

A Formal Model Of Semantic Web Service Ontology (Wsmo) Execution, Hai H. Wang, Nick Gibbins, Terry R. Payne, Ahmed Saleh, Jun Sun

Research Collection School Of Computing and Information Systems

Semantic Web services have been one of the most significant research areas within the semantic Web vision, and have been recognized as a promising technology that exhibits huge commercial potential. Current semantic Web service research focuses on defining models and languages for the semantic markup of all relevant aspects of services, which are accessible through a Web service interface. The Web service modelling ontology (WSMO) is one of the most significant semantic Web service framework proposed to date. To support the standardization and tool support of WSMO, a formal semantics of the language is highly desirable. As there are a …

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Comp-Ref: A Technique To Guide The Delegation Of Responsibilities To Components In Software Systems, Subhajit Datta, Robert Van Engelen Apr 2008

Comp-Ref: A Technique To Guide The Delegation Of Responsibilities To Components In Software Systems, Subhajit Datta, Robert Van Engelen

Research Collection School Of Computing and Information Systems

In software systems, components collaborate to collectively fulfill requirements. A key concern of software design is the delegation of responsibilities to components such that user needs are most expediently met. This paper presents the COMP-REF technique based on a set of metrics and Linear Programming (LP) to guide the allocation of responsibilities of a system’s components. We define the metrics Aptitude Index, Requirement Set, and Concordance Index to extract some design characteristics and use these metrics in an optimization algorithm. Results from experimental validation of the COMP-REF technique across a range of software systems are reported. We also …

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Building A Web Of Trust Without Explicit Trust Ratings, Young Ae Kim, Minh-Tam Le, Hady W. Lauw, Ee Peng Lim, Haifeng Liu, Jaideep Srivastava Apr 2008

Building A Web Of Trust Without Explicit Trust Ratings, Young Ae Kim, Minh-Tam Le, Hady W. Lauw, Ee Peng Lim, Haifeng Liu, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

A satisfactory and robust trust model is gaining importance in addressing information overload, and helping users collect reliable information in online communities. Current research on trust prediction strongly relies on a web of trust, which is directly collected from users based on previous experience. However, the web of trust is not always available in online communities and even though it is available, it is often too sparse to predict the trust value between two unacquainted people with high accuracy. In this paper, we propose a framework to derive degree of trust based on users' expertise and users' affinity for certain …

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Measurement And Estimation Of Network Qos Among Peer Xbox 360 Game Players, Youngki Lee, Sharad Agarwal, Chris Butcher, Jitu Padhye Apr 2008

Measurement And Estimation Of Network Qos Among Peer Xbox 360 Game Players, Youngki Lee, Sharad Agarwal, Chris Butcher, Jitu Padhye

Research Collection School Of Computing and Information Systems

The research community has proposed several techniques for estimating the quality of network paths in terms of delay and capacity. However, few techniques have been studied in the context of large deployed applications. Network gaming is an application that is extremely sensitive to network path quality [1,2,3]. Yet, the quality of network paths among players of large, wide-area games and techniques for estimating it have not received much attention from the research community.

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Rate-Diversity And Resource-Aware Broadcast And Multicast In Multi-Rate Wireless Mesh Networks, Bao Hua Liu, Chun Tung Chou, Archan Misra, Sanjay Jha Apr 2008

Rate-Diversity And Resource-Aware Broadcast And Multicast In Multi-Rate Wireless Mesh Networks, Bao Hua Liu, Chun Tung Chou, Archan Misra, Sanjay Jha

Research Collection School Of Computing and Information Systems

This paper focuses on the problem of increasing the traffic capacity (volume of admissible traffic) of broadcast and multicast flows in a wireless mesh network (WMN). We study and suggest routing strategies where the process of constructing the forwarding tree considers three distinct features: (a) the ability of individual mesh nodes to perform link-layer broadcasts at multiple rates, (b) the wireless broadcast advantage, whereby a single broadcast transmission covers multiple neighboring receivers and (c) the residual transmission capacity at a WMN node, subject to intereference-based constraints from existing traffic flows in its neighborhood. Our metric of interest is the total …

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