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Research Collection School Of Computing and Information Systems

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Hierarchical Mobility Management For Voip Traffic, Archan Misra, Subir Das, Anthony J. Mcauley Oct 2001

Hierarchical Mobility Management For Voip Traffic, Archan Misra, Subir Das, Anthony J. Mcauley

Research Collection School Of Computing and Information Systems

A hierarchical IP-based mobility management mechanism is proposed for VoIP applications. The suggested mechanism uses the DMA (dynamic mobility agent) architecture, based on IDMP (intra-domain mobility management protocol), for managing intra-domain mobility and the dynamic binding mechanism of SIP (session initiation protocol) for managing global mobility. This combination of network and application layer mobility management reduces the global signaling load, provides fast handoff for ongoing conversations, enables efficient global transport and supports IP-layer paging.

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Mining Multi-Level Rules With Recurrent Items Using Fp'-Tree, Kok-Leong Ong, Wee-Keong Ng, Ee Peng Lim Oct 2001

Mining Multi-Level Rules With Recurrent Items Using Fp'-Tree, Kok-Leong Ong, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Association rule mining has received broad research in the academic and wide application in the real world. As a result, many variations exist and one such variant is the mining of multi-level rules. The mining of multi-level rules has proved to be useful in discovering important knowledge that conventional algorithms such as Apriori, SETM, DIC etc., miss. However, existing techniques for mining multi-level rules have failed to take into account the recurrence relationship that can occur in a transaction during the translation of an atomic item to a higher level representation. As a result, rules containing recurrent items go unnoticed. …

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Exploiting Image Indexing Techniques In Dct Domain, Chong-Wah Ngo, Ting-Chuen Pong, Ronald T. Chin Sep 2001

Exploiting Image Indexing Techniques In Dct Domain, Chong-Wah Ngo, Ting-Chuen Pong, Ronald T. Chin

Research Collection School Of Computing and Information Systems

This paper is concerned with the indexing and retrieval of images based on features extracted directly from the JPEG discrete cosine transform (DCT) domain. We examine possible ways of manipulating DCT coefficients by standard image analysis approaches to describe image shape, texture, and color. Through the Mandala transformation, our approach groups a subset of DCT coefficients to form ten blocks. Each block represents a particular frequency content of the original image. Two blocks are used to model rough object shape; nine blocks to describe subband properties; and one block to compute color distribution. As a result, the amount of data …

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Vide: A Visual Data Extraction Environment For The Web, Yi Li, Wee-Keong Ng, Ee Peng Lim Sep 2001

Vide: A Visual Data Extraction Environment For The Web, Yi Li, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

With the rapid growth of information on the Web, a means to combat information overload is critical. In this paper, we present ViDE (Visual Data Extraction), an interactive web data extraction environment that supports efficient hierarchical data wrapping of multiple web pages. ViDE has two unique features that differentiate it from other extraction mechanisms. First, data extraction rules can be easily specified in a graphical user interface that is seamlessly integrated with a web browser. Second, ViDE introduces the concept of grouping which unites the extraction rules for a set of documents with the navigational patterns that exist among them. …

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Role Of Use Case Diagram In Requirement Analysis, Keng Siau, L. Lee Aug 2001

Role Of Use Case Diagram In Requirement Analysis, Keng Siau, L. Lee

Research Collection School Of Computing and Information Systems

Since its debut and acceptance as a de facto standard of the object-oriented paradigm, UML has receivedcontroversial reviews. The most controversial diagramming technique in UML is undoubtedly the Use Casediagrams. Some claim that Use Case diagrams do not play a valuable role in requirement analysis. Othersargue that Use Case diagrams captured neither the static nor the dynamic aspects of the systems. The objective of this study is to investigate the role and value of Use Case diagrams in requirement analysis. We will investigate the information content of Use Case diagram and its role in requirement analysis.

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Research Issues In Human-Computer Interaction In The Web-Based Environment, Fiona Fui-Hoon Nah, Sid Davis Aug 2001

Research Issues In Human-Computer Interaction In The Web-Based Environment, Fiona Fui-Hoon Nah, Sid Davis

Research Collection School Of Computing and Information Systems

The Internet and WWW are revolutionizing our daily lives and the way business is conducted. Since 1997, the Web has gradually evolved into a true economy and a new frontier for business. In this new Internet age, the design of a quality Web site is critical to the success of businesses. To attract and retain visitors, Web sites need to be human-centered, easy and quick to navigate, and speak the visitor’s language. User experience with the Web site is also important. The experience should be in line with the user’s goal and should feel natural to the user. Unfortunately, principles …

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Video Partitioning By Temporal Slice Coherency, Chong-Wah Ngo, Ting-Chuen Pong, Roland T. Chin Aug 2001

Video Partitioning By Temporal Slice Coherency, Chong-Wah Ngo, Ting-Chuen Pong, Roland T. Chin

Research Collection School Of Computing and Information Systems

We present a novel approach for video partitioning by detecting three essential types of camera breaks, namely cuts, wipes, and dissolves. The approach is based on the analysis of temporal slices which are extracted from the video by slicing through the sequence of video frames and collecting temporal signatures. Each of these slices contains both spatial and temporal information from which coherent regions are indicative of uninterrupted video partitions separated by camera breaks. Properties could further be extracted from the slice for both the detection and classification of camera breaks. For example, cut and wipes are detected by color-texture properties, …

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Critical Factors For Successful Implementation Of Enterprise Systems, Fiona Fui-Hoon Nah, J. Lau, J. Kuang Aug 2001

Critical Factors For Successful Implementation Of Enterprise Systems, Fiona Fui-Hoon Nah, J. Lau, J. Kuang

Research Collection School Of Computing and Information Systems

Enterprise resource planning (ERP) systems have emerged as the core of successful information management and the enterprise backbone of organizations. The difficulties of ERP implementations have been widely cited in the literature but research on the critical factors for initial and ongoing ERP implementation success is rare and fragmented. Through a comprehensive review of the literature, 11 factors were found to be critical to ERP implementation success – ERP teamwork and composition; change management program and culture; top management support; business plan and vision; business process reengineering with minimum customization; project management; monitoring and evaluation of performance; effective communication; software …

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A Multi-Agent Framework For Supporting Intelligent Fourth-Party Logistics, Hoong Chuin Lau, G. Lo Aug 2001

A Multi-Agent Framework For Supporting Intelligent Fourth-Party Logistics, Hoong Chuin Lau, G. Lo

Research Collection School Of Computing and Information Systems

A distributed intelligent agent-based framework that supports fourth-party logistics optimization under a web-based e-Commerce environment has been proposed in this paper. In the framework, customer job requests come through an e-Procurement service. These requests are consolidated and pushed to the e-Market Place service periodically. The e-Market Place then serves as a broker that allows intelligent agents to bid to serve these requests optimally in real-time by solving multiple instances of underlying logistics optimization problem. The resulting system was implemented based on the Java 2 Enterprise Edition (J2EE) platform using distributed system technology for communication between objects.

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Analysis Of A New Vehicle Scheduling And Location Problem, Ebru K. Bish, Thin Yin Leong, Chun-Lun Li, Jonathan W. C. Ng, David Simchi-Levi Aug 2001

Analysis Of A New Vehicle Scheduling And Location Problem, Ebru K. Bish, Thin Yin Leong, Chun-Lun Li, Jonathan W. C. Ng, David Simchi-Levi

Research Collection School Of Computing and Information Systems

We consider a container terminal discharging containers from a ship and locating them in the terminal yard. Each container has a number of potential locations in the yard where it can be stored. Containers are moved from the ship to the yard using a fleet of vehicles, each of which can carry one container at a time. The problem is to assign each container to a yard location and dispatch vehicles to the containers so as to minimize the time it takes to download all the containers from the ship. We show that the problem is NP-hard and develop a …

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Autoconfiguration, Registration And Mobility Management For Pervasive Computing, Archan Misra, Subir Das, Anthony Mcauley, Sajal K. Das Aug 2001

Autoconfiguration, Registration And Mobility Management For Pervasive Computing, Archan Misra, Subir Das, Anthony Mcauley, Sajal K. Das

Research Collection School Of Computing and Information Systems

In the vision of pervasive computing, users will exchange information and control their environments from anywhere using various wireline/wireless networks and computing devices. We believe that current protocols, such as DHCP, PPP, and Mobile IP, must be enhanced to support pervasive network access. In particular, this article identifies three fundamental functions: autoconfiguration, registration, and mobility management, that need such enhancements. Realizing that the IP autoconfiguration capabilities must be extended to configure routers and large dynamic networks, we first describe our autoconfiguration solution based on the dynamic configuration and distribution protocol (DCDP). Second, we discuss why providing user-specific services over a …

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Mobile Commerce: Promises, Challenges And Research Agenda, Keng Siau, Ee Peng Lim Jul 2001

Mobile Commerce: Promises, Challenges And Research Agenda, Keng Siau, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Advances in wireless technology increase the number of mobile device users and give pace to the rapid development of e-commerce using these devices. The new type of e-commerce, conducting transactions via mobile terminals, is called mobile commerce. Due to its inherent characteristics such as ubiquity, personalization, flexibility, and dissemination, mobile commerce promises businesses unprecedented market potential, great productivity, and high profitability. This paper presents an overview of mobile commerce development by examining the enabling technologies, the impact of mobile commerce on the business world, and the implications to mobile commerce providers. The paper also provides an agenda for future research …

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Application-Centric Analysis Of Ip-Based Mobility Management Techniques, Archan Misra, Subir Das, Prathima Agrawal Jul 2001

Application-Centric Analysis Of Ip-Based Mobility Management Techniques, Archan Misra, Subir Das, Prathima Agrawal

Research Collection School Of Computing and Information Systems

This paper considers three applications—VoIP, mobile Web access and mobile server-based data transfers—and evaluates the applicability of various IP-based mobility management mechanisms. We first survey the features and characteristics of various IP mobility protocols, such as MIPv4, MIPv6, MIP-RO, SIP, CIP, HAWAII, MIP-RR and IDMP, and then evaluate their utility on an application-specific basis. The diversity in the mobility-related requirements ensures that no single mobility solution is universally applicable. We recommend a hierarchical mobility architecture. The framework uses our Dynamic Mobility Agent (DMA) architecture for managing intra-domain mobility and multiple application-based binding protocols for supporting inter-domain mobility. Thus, we recommend …

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Secure And Private Distribution Of Online Video And Some Related Cryptographic Issues, Feng Bao, Robert H. Deng, Peirong Bao, Yan Guo, Hongjun Wu Jul 2001

Secure And Private Distribution Of Online Video And Some Related Cryptographic Issues, Feng Bao, Robert H. Deng, Peirong Bao, Yan Guo, Hongjun Wu

Research Collection School Of Computing and Information Systems

With the rapid growth of broadband infrastructure, it is thought that the bottleneck for video-on-demand service through Internet is being cleared. However, digital video content protection and consumers privacy protection emerge as new major obstacles. In this paper we propose an online video distribution system with strong content security and privacy protection. We mainly focus on the study of security and privacy problems related to the system. Besides presenting the new system, we intensively discuss some relevant cryptographic issues, such as content protection, private information retrieval, super-speed encryption/decryption for video, and PKC with fast decryption etc. The paper can be …

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Genetic Algorithms For Communications Network Design - An Empirical Study Of The Factors That Influence Performance, Hsinghua Chou, G. Premkumar, Chao-Hsien Chu Jun 2001

Genetic Algorithms For Communications Network Design - An Empirical Study Of The Factors That Influence Performance, Hsinghua Chou, G. Premkumar, Chao-Hsien Chu

Research Collection School Of Computing and Information Systems

We explore the use of GAs for solving a network optimization problem, the degree-constrained minimum spanning tree problem. We also examine the impact of encoding, crossover, and mutation on the performance of the GA. A specialized repair heuristic is used to improve performance. An experimental design with 48 cells and ten data points in each cell is used to examine the impact of two encoding methods, three crossover methods, two mutation methods, and four networks of varying node sizes. Two performance measures, solution quality and computation time, are used to evaluate the performance. The results obtained indicate that encoding has …

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Implementation And Performance Evaluation Of Telemip, Kaushik Chakraborty, Archan Misra, Subir Das, Anthony J. Mcauley, Ashutosh Dutta, Sajal K. Das Jun 2001

Implementation And Performance Evaluation Of Telemip, Kaushik Chakraborty, Archan Misra, Subir Das, Anthony J. Mcauley, Ashutosh Dutta, Sajal K. Das

Research Collection School Of Computing and Information Systems

In this paper, we present our implementation of TeleMIP a two-level architecture for IP based mobility management TeleMIP essentially uses an Intra-Domain Mobility Management Protocol IDMP for managing mobility within a domain and Mobile IP for supporting inter-domain global mobility. Unlike other proposed schemes for intra-domain mobility management IDMP uses two care of addresses for mobility management The global care of address is relatively stable and identifies the mobile nodes current domain[1] while the local care of address changes every time the mobile changes subnets and identifies the mobiles current point of attachment. The paper describes our TeleMIP implementation based …

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Effect Of Exponential Averaging On The Variability Of A Red Queue, Archan Misra, Teunis Ott, John Baras Jun 2001

Effect Of Exponential Averaging On The Variability Of A Red Queue, Archan Misra, Teunis Ott, John Baras

Research Collection School Of Computing and Information Systems

The paper analyzes how using a longer memory of the past queue occupancy in computing the average queue occupancy affects the stability and variability of a RED queue. Extensive simulation studies with both persistent and Web TCP sources are used to study the variance of the RED queue as a function of the memory of the averaging process. Our results show that there is very little performance improvement (and in fact, possibly significant performance degradation) if the length of memory is increased beyond a very small value. Contrary to current practice, our results show that a longer memory reduces the …

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The Next Wave In Erp Implementation, Keng Siau, Y. Tian May 2001

The Next Wave In Erp Implementation, Keng Siau, Y. Tian

Research Collection School Of Computing and Information Systems

Although the benefits of ERP are obvious, the risks and costs associated with it are very high. Some problems in implementing ERP system are documented, but the real challenge comes from the Internet and E-business. ERP is an enterprise wide system whose purpose is to achieve internal efficiency, while E-business cuts across different enterprises and extends the individual value chain into an Internet based, dynamic process aimed at maximizing external efficiency. To survive the E-business challenge, the arguably single, and also the best, solution for ERP systems is to integrate with E-business applications, which we call ERP II. By properly …

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Idmp-Based Fast Handoffs And Paging In Ip-Based Cellular Networks, Archan Misra, Subir Das, Ashutosh Dutta, Sajal K. Das May 2001

Idmp-Based Fast Handoffs And Paging In Ip-Based Cellular Networks, Archan Misra, Subir Das, Ashutosh Dutta, Sajal K. Das

Research Collection School Of Computing and Information Systems

We consider the use of our previously proposed Intra-Domain Mobility Management Protocol (IDMP) in fourth-generation mobile networks. On evaluating the heterogeneous access technologies, cellular layouts, and application characteristics of 4G environments, we realize a need to reduce both handoff latency and the frequency of mobility-related signaling. We first present IDMP's fast intradomain handoff mechanism that uses a duration-limited proactive packet multicasting solution. We quantify the expected buffering requirements of our proposed multicasting scheme for typical 4G network characteristics and compare it with alternative IP-based fast handoff solutions. We also present a paging scheme under IDMP that replicates the current cellular …

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Topic Detection, Tracking, And Trend Analysis Using Self-Organizing Neural Networks, Kanagasabai Rajaraman, Ah-Hwee Tan Apr 2001

Topic Detection, Tracking, And Trend Analysis Using Self-Organizing Neural Networks, Kanagasabai Rajaraman, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

We address the problem of Topic Detection and Tracking (TDT) and subsequently detecting trends from a stream of text documents. Formulating TDT as a clustering problem in a class of self-organizing neural networks, we propose an incremental clustering algorithm. On this setup we show how trends can be identified. Through experimental studies, we observe that our method enables discovering interesting trends that are deducible only from reading all relevant documents.

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Tcp Hack: Tcp Header Checksum Option To Improve Performance Over Lossy Links, Rajesh Krishna Balan, Boon Peng Lee, Renjish Kumar, Jacob Lillykutty, Winston Seah, A. L. Ananda Apr 2001

Tcp Hack: Tcp Header Checksum Option To Improve Performance Over Lossy Links, Rajesh Krishna Balan, Boon Peng Lee, Renjish Kumar, Jacob Lillykutty, Winston Seah, A. L. Ananda

Research Collection School Of Computing and Information Systems

Wireless networks have become increasingly common and an increasing number of devices are communicating with each other over lossy links. Unfortunately, TCP performs poorly over lossy links as it is unable to differentiate the loss due to packet corruption from that due to congestion. We present an extension to TCP which enables TCP to distinguish packet corruption from congestion in lossy environments resulting in improved performance. We refer to this extension as the HeAder ChecKsum option (HACK). We implemented our algorithm in the Linux kernel and performed various tests to determine its effectiveness. Our results have shown that HACK performs …

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Predictive Self-Organizing Networks For Text Categorization, Ah-Hwee Tan Apr 2001

Predictive Self-Organizing Networks For Text Categorization, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

This paper introduces a class of predictive self-organizing neural networks known as Adaptive Resonance Associative Map (ARAM) for classification of free-text documents. Whereas most sta- tistical approaches to text categorization derive classification knowledge based on training examples alone, ARAM performs supervised learn- ing and integrates user-defined classification knowledge in the form of IF-THEN rules. Through our experiments on the Reuters-21578 news database, we showed that ARAM performed reasonably well in mining categorization knowledge from sparse and high dimensional document feature space. In addition, ARAM predictive accuracy and learning efficiency can be improved by incorporating a set of rules derived from …

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A Framework For Performance And Value Assessment Of E-Business Systems In Corporate Travel Distribution, A.M. Chircu, Robert J. Kauffman Jan 2001

A Framework For Performance And Value Assessment Of E-Business Systems In Corporate Travel Distribution, A.M. Chircu, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

This chapter proposes and illustrates a framework that the authors call the value life cycle for e-commerce systems. Based on recent research results that relate to technology investments in the corporate travel industry and related theoretical and empirical perspectives, the authors lay out the corporate travel e-commerce system solutions value life cycle. The perspective involves estimating the maximum value that that an organization can obtain by implementing an e-commerce system in a specific industry and competitive environment. It also considers multiple factors that act as value contingencies for the implementation process. These create barriers to value accrual and to …

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Unified Modeling Language: A Complexity Analysis, Keng Siau, Q. Cao Jan 2001

Unified Modeling Language: A Complexity Analysis, Keng Siau, Q. Cao

Research Collection School Of Computing and Information Systems

Unified Modeling Language (UML) is the standard visual modeling language for Object Oriented (OO) systems development, but it has been criticized for its complexity, inconsistent semantics, and ambiguous constructs. A set of complexity indices for UML and the nine diagramming techniques in UML was compiled recently. The complexity analysis is formulated based on the number of constructs, associations, roles, and so forth, in a modeling method. We argue that this set of metrics provides an indication of the theoretical complexity of the modeling methods. On the other hand, the theoretical complexity of the modeling methods does not necessarily relate to …

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Ontologies And Electronic Commerce, Dieter Fensel, Deborah L. Mcguinness, Ellen Schulten, Wee-Keong Ng, Ee Peng Lim, Guanghao Yan Jan 2001

Ontologies And Electronic Commerce, Dieter Fensel, Deborah L. Mcguinness, Ellen Schulten, Wee-Keong Ng, Ee Peng Lim, Guanghao Yan

Research Collection School Of Computing and Information Systems

Ontologies are the first step toward realizing the full power of online e-commerce. Ontologies enable machine-understandable semantics of data, and building this data infrastructure will enable completely new kinds of automated services. Software agents can search for products, form buyer and seller coalitions, negotiate about products, or help automatically configure products and services according to specified user requirements. The combination of machine-processable semantics of data based on ontologies and the development of many specialized reasoning services will bring the Web to its full power. The authors discuss: taxonomies; information sources; future issues; business viewpoints; the e-marketplace; and B2B e-commerce standardisation …

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Collaborative Model And Algorithms For Supporting Real-Time Distribution Logistics Systems, Hoong Chuin Lau, Qi Zhang Liu Dec 2000

Collaborative Model And Algorithms For Supporting Real-Time Distribution Logistics Systems, Hoong Chuin Lau, Qi Zhang Liu

Research Collection School Of Computing and Information Systems

We study a complex optimization problem that arises due to an emerging trend in distribution logistics. The problem involves the integration of an inventory management problem and the vehicle routing problem with time windows, both of which are known to be NP-hard. We describe a collaborative approach to solve this problem in real-time. The novelty of our approach lies in the tight algorithmic integration between two sub-problems, and suggests an elegant scheme to deal with other integrated optimization problems of the same nature. For first sub-problem, we will present two algorithms: a complete mathematical model integrating integer programming with constraint …

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Knowledge Discovery As An Aid To Organizational Creativity, Keng Siau Dec 2000

Knowledge Discovery As An Aid To Organizational Creativity, Keng Siau

Research Collection School Of Computing and Information Systems

Computers can play an important role in the creative process. With the abundance of data and increasing speed of computers, creativity can now be stimulated and enhanced with knowledge mined from available data. The process is known as knowledge discovery or data mining. Knowledge discovery is the process of discovering interesting associations among data in the database. Users in the creativity process can feed on the discovered associations to generate creative solutions. The objective of this paper is to present knowledge discovery as an aid to creativity. The paper first presents the concept of knowledge discovery and then discusses the …

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Generalized Tcp Congestion Avoidance And Its Effect On Bandwidth Sharing And Variability, Archan Misra, John Baras, Teunis Ott Dec 2000

Generalized Tcp Congestion Avoidance And Its Effect On Bandwidth Sharing And Variability, Archan Misra, John Baras, Teunis Ott

Research Collection School Of Computing and Information Systems

To model possible suggested changes in TCP window adaptation in response to randomized feedback, such as ECN (explicit congestion notification), we formulate a generalized version of the TCP congestion avoidance algorithm. We first consider multiple such generalized TCP flows sharing a bottleneck buffer under the assured service model and use a fixed point technique to obtain the mean window sizes and throughputs for the TCP flows, To further study how changes in the adaptation algorithm affect the variability in the throughput, we use an analytical-cum-numerical technique to derive the window distribution (and related statistics) of a single generalized flow under …

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Extensible Mpeg-4 Textual Format (Xmt), Michelle Kim, Steve Wood, Lai-Tee Cheok Nov 2000

Extensible Mpeg-4 Textual Format (Xmt), Michelle Kim, Steve Wood, Lai-Tee Cheok

Research Collection School Of Computing and Information Systems

This paper describes the Extensible MPEG-4 Textual format (XMT), a framework for representing MPEG-4 scene description using a textual syntax. The XMT allows the content authors to exchange their content with other authors, tools or service providers, and facilitates interoperability with both the X3D, developed by the Web3D consortium, and the Synchronized Multimedia Integration Language (SM1L) from the W3C consortium.

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Using 'Drop-Biasing' To Stabilize The Occupancy Of Random-Drop Queues With Tcp Traffic, Archan Misra, Teunis Ott, John Baras Nov 2000

Using 'Drop-Biasing' To Stabilize The Occupancy Of Random-Drop Queues With Tcp Traffic, Archan Misra, Teunis Ott, John Baras

Research Collection School Of Computing and Information Systems

The paper describes how the use of ‘drop-biasing’, a technique to control the distribution of the gap between consecutive packet losses in random drop queues (such as RED) can be used to reduce the variability of the queue occupancy with TCP traffic. Reducing the variance of the queue occupancy reduces delay jitter for buffered packets, as well as decreases the likelihood of buffer underflow. We find that modifying the packet drop probabilities to ensure a minimum separation between consecutive packet drops serves to decrease the variability in the queue occupancy. This is really achieved as a result of the increased …

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