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Articles 8701 - 8730 of 9440

Full-Text Articles in Physical Sciences and Mathematics

Evaluation Criteria For Information Systems Development Methodologies, Keng Siau, Xin Tan Aug 2005

Evaluation Criteria For Information Systems Development Methodologies, Keng Siau, Xin Tan

Research Collection School Of Computing and Information Systems

The evaluation of information systems development methodologies is becoming increasingly important. The lack of a commonly acceptable set of criteria for evaluation, however, hinders aggregating knowledge from field studies. Our study attempts to fill the gap. To reduce the effects of subjectivity, we surveyed the opinions of a group (28) of experienced IS researchers. Fifty-one criteria were generated from the research participants. A systematic content analysis technique will be applied for grouping the unique criteria into general categories. Upon completion, our study can make both academic and practical contributions in evaluating ISD methodologies.

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Medoid Queries In Large Spatial Databases, Kyriakos Mouratidis, Dimitris Papadias, Spiros Papadimitriou Aug 2005

Medoid Queries In Large Spatial Databases, Kyriakos Mouratidis, Dimitris Papadias, Spiros Papadimitriou

Research Collection School Of Computing and Information Systems

Assume that a franchise plans to open k branches in a city, so that the average distance from each residential block to the closest branch is minimized. This is an instance of the k-medoids problem, where residential blocks constitute the input dataset and the k branch locations correspond to the medoids. Since the problem is NP-hard, research has focused on approximate solutions. Despite an avalanche of methods for small and moderate size datasets, currently there exists no technique applicable to very large databases. In this paper, we provide efficient algorithms that utilize an existing data-partition index to achieve low CPU …

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Constrained Shortest Path Computation, Manolis Terrovitis, Spiridon Bakiras, Dimitris Papadias, Kyriakos Mouratidis Aug 2005

Constrained Shortest Path Computation, Manolis Terrovitis, Spiridon Bakiras, Dimitris Papadias, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

This paper proposes and solves a-autonomy and k-stops shortest path problems in large spatial databases. Given a source s and a destination d, an aautonomy query retrieves a sequence of data points connecting s and d, such that the distance between any two consecutive points in the path is not greater than a. A k-stops query retrieves a sequence that contains exactly k intermediate data points. In both cases our aim is to compute the shortest path subject to these constraints. Assuming that the dataset is indexed by a data-partitioning method, the proposed techniques initially compute a sub-optimal path by …

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Wmxml: A System For Watermarking Xml Data, Xuan Zhou, Hwee Hwa Pang, Kian-Lee Tan, Dhruv Mangla Aug 2005

Wmxml: A System For Watermarking Xml Data, Xuan Zhou, Hwee Hwa Pang, Kian-Lee Tan, Dhruv Mangla

Research Collection School Of Computing and Information Systems

As increasing amount of data is published in the form of XML, copyright protection of XML data is becoming an important requirement for many applications. While digital watermarking is a widely used measure to protect digital data from copyright offences, the complex and flexible construction of XML data poses a number of challenges to digital watermarking, such as re-organization and alteration attacks. To overcome these challenges, the watermarking scheme has to be based on the usability of data and the underlying semantics like key attributes and functional dependencies. In this paper, we describe WmXML, a system for watermarking XML documents. …

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Impact On Open Source Software Performance: A View From Social Structure, Y. Long, Keng Siau Aug 2005

Impact On Open Source Software Performance: A View From Social Structure, Y. Long, Keng Siau

Research Collection School Of Computing and Information Systems

Open source software (OSS) has drawn increasing attention from both practitioners and researchers in recent years. However, few empirical studies have investigated the interaction process of OSS teams during OSS development. This research has two primary objectives. The first is to study the social structure of OSS teams. The second is to investigate the factors impacting the social structure of OSS teams as well as the effects of the social structure on OSS performance. Based on the social structure and social network theory, and group-related theories, this paper first presented a general research framework, then discussed research methodology, and finally …

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Towards A Theoretical Framework Of Information Systems Development Success, Y. Long, Keng Siau, M. Ling Aug 2005

Towards A Theoretical Framework Of Information Systems Development Success, Y. Long, Keng Siau, M. Ling

Research Collection School Of Computing and Information Systems

Information systems development (ISD) is a complicated process involving interconnected resources, objects, and outcomes. The importance of ISD has attracted long-term interests from both researchers and practitioners. Based on the input-process-output model, this paper developed a conceptual framework of ISD success through a systematic literature review. The paper argues that ISD is a comprehensive and interactive process among individuals, teams, and organization. These factors impact ISD process, and further affect ISD success.

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Personalization Of Web Services: A Study On The Fit Between Web Tasks And Personalization Mechanisms, Fiona Fui-Hoon Nah, Keng Siau, Min Ling Aug 2005

Personalization Of Web Services: A Study On The Fit Between Web Tasks And Personalization Mechanisms, Fiona Fui-Hoon Nah, Keng Siau, Min Ling

Research Collection School Of Computing and Information Systems

Personalization is increasingly being considered an important ingredient of Web applications. In most cases, personalization techniques and mechanisms are used for tailoring information services to user needs. It is motivated by the recognition that a user has needs, and meeting them successfully is likely to lead to a satisfying relationship and re-use of the Web services offered. However, if the personalization mechanisms do not match the needs depicted by the tasks, it will decrease user satisfaction and performance. In this research, we use the cognitive fit theory to examine the fit between personalization mechanisms and Web tasks.

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Privacy Issues In The Era Of Ubiquitous Commerce, Holtjona Galanxhi, Fiona Fui-Hoon Nah Aug 2005

Privacy Issues In The Era Of Ubiquitous Commerce, Holtjona Galanxhi, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

The vision of ubiquitous commerce (u‐commerce) is realized through the convergence of electronic, mobile, television, voice and silent commerce applications. The ubiquity, universality, uniqueness and unison of u‐commerce will provide two principal benefits for individual users and businesses: increased convenience as well as more personalized and customized services. However, u‐commerce will also bring emerging issues such as a greater degree of privacy concerns that will impact individual users, companies and society at large. This paper proposes and elaborates on a conceptual framework for privacy in the u‐commerce era. This framework is developed based on Lessig's macro‐level perspective and Adams' micro‐level …

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Values Of Silent Commerce: A Study Using Value-Focused Thinking Approach, H. Sheng, Fiona Fui-Hoon Nah, Keng Siau Aug 2005

Values Of Silent Commerce: A Study Using Value-Focused Thinking Approach, H. Sheng, Fiona Fui-Hoon Nah, Keng Siau

Research Collection School Of Computing and Information Systems

Silent commerce is a special type of u-commerce that uses RFID and sensor technologies to make objects intelligent and interactive. The unique features available in silent commerce will provide benefits and added values to users. This study aims to uncover the values of silent commerce from the customers’ perspectives and understand what customers desire and expect from silent commerce. The scenario-based method was adopted to provide subjects with the necessary background information and knowledge about the emerging silent commerce phenomenon. The Value-Focused Thinking approach, which provides a systematic way to articulate and organize values, was used to identify the values …

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Toward Practical Measures Of Complexity In Real-Time Modeling Methods, J. Erickson, Keng Siau Aug 2005

Toward Practical Measures Of Complexity In Real-Time Modeling Methods, J. Erickson, Keng Siau

Research Collection School Of Computing and Information Systems

Systems development methods have become more complex, concurrently with many of today’s systems. UML has been criticized for its complexity. Using Rossi and Brinkkemper’s (1996) complexity metrics, Siau and Cao, (2001) completed a complexity analysis of UML and other modeling techniques, finding that UML is more complex than other techniques. Siau, Erickson and Lee (2002) proposed that Rossi and Brinkkemper’s metrics present the theoretical maximum complexity, as opposed to a practitioner-based complexity, that must be less than the theoretical maximum. Erickson and Siau (2004) proposed that a subset of UML (a kernel) composed of the most commonly used constructs, could …

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An Investigation Into The Continued Use Of Unified Modeling Language (Uml) In Information Systems Development, Keng Siau, X. Tan Aug 2005

An Investigation Into The Continued Use Of Unified Modeling Language (Uml) In Information Systems Development, Keng Siau, X. Tan

Research Collection School Of Computing and Information Systems

As the de facto standard for object-oriented modeling language, UML is expected to play an increasingly important role in information systems development. The long-term viability and eventual success of UML depend, to a great extent, on the continued use by UML users such as developers and analysts. Systematic investigations on UML’s continued use have been missing from contemporary discussions. Our study attempts to fill this gap in the literature. We developed a research model, which is primarily based on the Expectation Disconfirmation Theory (EDT). According to this model, UML users’ perceived discrepancy between pre-adoption expectation and post-adoption perceived performance, which …

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A Semiotics View Of Modeling Method Complexity – The Case Of Uml, Keng Siau, Y. Tian Aug 2005

A Semiotics View Of Modeling Method Complexity – The Case Of Uml, Keng Siau, Y. Tian

Research Collection School Of Computing and Information Systems

Unified Modeling Language (UML) is the standard modeling language for object oriented system development. Despite its status as a standard, UML’s formal specification is fuzzy and its theoretical foundation is weak. Semiotics, the study of signs, provides us good theoretical foundation for UML research as UML graphical notations are some kinds of signs. In this research, we use semiotics to study the graphical notations in UML. We hypothesized that using iconic signs as UML graphical notations leads to more accurate representation and arouses fewer connotations than using symbolic signs. Since symbolic signs involve more learning efforts, we assume that expert …

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Introduction: Human-Computer Interaction Studies In Management Information Systems, Fiona Fui-Hoon Nah, P. Zhang, S. Mccoy Aug 2005

Introduction: Human-Computer Interaction Studies In Management Information Systems, Fiona Fui-Hoon Nah, P. Zhang, S. Mccoy

Research Collection School Of Computing and Information Systems

Human-computer interaction (HCI) is a critical area of research and practice that spans several disciplines, including industrial engineering, management information systems (MIS), computer science, information science, psychology, sociology, and anthropology. HCI research within the MIS discipline has distinct features shaped by the evolution and current state of MIS. Originating as applied computer science in the 1970s, MIS gradually transformed into a more social science–oriented discipline (Baskerville & Myers, 2002). MIS is broadly defined as “the effective design, delivery, and use of information systems in organizations” (Keen, 1980, p. 14). The two distinguishing features of MIS compared to other "homes" of …

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Web Browsing And Spyware Intrusion, S. Shukla, Fiona Fui-Hoon Nah Aug 2005

Web Browsing And Spyware Intrusion, S. Shukla, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

Spyware poses serious privacy and security issues to users of e-commerce and m-commerce [3, 5, 8]. Microsoft claims that half of all computer crashes reported by its customers were caused by spyware and its equivalents. Spyware is also responsible for about 12% of all technical support calls and accounts for the biggest category of customer complaints, according to Dell

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Privacy Issues In The Era Of Ubiquitous Commerce, Holtjona Galanxhi, Fiona Fui-Hoon Nah Aug 2005

Privacy Issues In The Era Of Ubiquitous Commerce, Holtjona Galanxhi, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

The vision of ubiquitous commerce (u-commerce) is realized through the convergence of electronic, mobile, television, voice and silent commerce applications. The ubiquity, universality, uniqueness, and unison of u-commerce will provide two principal benefits for individual users and companies: increased convenience as well as more personalized and customized services. However, u-commerce will also bring new issues such as a greater degree of privacy concerns that will impact individual users, companies, and the society at large. This paper proposes and elaborates on a conceptual framework for privacy in the u-commerce era. It combines Lessig’s macro-level perspective – the four-factor model of privacy …

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Web Mining - The Ontology Approach, Ee Peng Lim, Aixin Sun Aug 2005

Web Mining - The Ontology Approach, Ee Peng Lim, Aixin Sun

Research Collection School Of Computing and Information Systems

The World Wide Web today provides users access to extremely large number of Web sites many of which contain information of education and commercial values. Due to the unstructured and semi-structured nature of Web pages and the design idiosyncrasy of Web sites, it is a challenging task to develop digital libraries for organizing and managing digital content from the Web. Web mining research, in its last 10 years, has on the other hand made significant progress in categorizing and extracting content from the Web. In this paper, we represent ontology as a set of concepts and their inter-relationships relevant to …

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Dispatching Vehicles In A Mega Container Terminal, Ebru K. Bish, Frank Y. Chen, Thin Yin Leong, Barry L. Nelson, Jonathan W. C. Ng, David Simchi-Levi Aug 2005

Dispatching Vehicles In A Mega Container Terminal, Ebru K. Bish, Frank Y. Chen, Thin Yin Leong, Barry L. Nelson, Jonathan W. C. Ng, David Simchi-Levi

Research Collection School Of Computing and Information Systems

We consider a container terminal discharging and uploading containers to and from ships. The discharged containers are stored at prespecified storage locations in the terminal yard. Containers are moved between the ship area and the yard using a fleet of vehicles, each of which can carry one container at a time. The problem is to dispatch vehicles to the containers so as to minimize the total time it takes to serve a ship, which is the total time it takes to discharge all containers from the ship and upload new containers onto the ship. We develop easily implementable heuristic algorithms …

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Geogdl: A Web-Based Approach To Geography Examination, Ee Peng Lim, Dion Hoe-Lian Goh, Yin-Leng Theng Aug 2005

Geogdl: A Web-Based Approach To Geography Examination, Ee Peng Lim, Dion Hoe-Lian Goh, Yin-Leng Theng

Research Collection School Of Computing and Information Systems

The traditional educational approach with students as passive recipients has been the subject of criticism. A constructivist learner-centered approach towards education has been argued to produce greater internalization and application of knowledge compared to the traditional teacher-centered, transmission-oriented approach. Nevertheless, contemporary instructional design models argue for the use and integration of both approaches especially in complex learning tasks. This paper describes GeogDL, a Web-based application developed above a digital library of geographical resources for Singapore students preparing to take a national examination in geography. GeogDL is unique in that it not only provides an environment for active learning, it also …

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Tuning Tabu Search Strategies Via Visual Diagnosis, Steven Halim, Wee Chong Wan, Hoong Chuin Lau Aug 2005

Tuning Tabu Search Strategies Via Visual Diagnosis, Steven Halim, Wee Chong Wan, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

While designing working metaheuristics can be straightforward, tuning them to solve the underlying combinatorial optimization problem well can be tricky. Several tuning methods have been proposed but they do not address the new aspect of our proposed classification of the metaheuristic tuning problem: tuning search strategies. We propose a tuning methodology based on Visual Diagnosis and a generic tool called Visualizer for Metaheuristics Development Framework(V-MDF) to address specifically the problem of tuning search (particularly Tabu Search) strategies. Under V-MDF, we propose the use of a Distance Radar visualizer where the human and computer can collaborate to diagnose the occurrence of …

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Translation Initiation Sites Prediction With Mixture Gaussian Models In Human Cdna Sequences, G. Li, Tze-Yun Leong, Louxin Zhang Aug 2005

Translation Initiation Sites Prediction With Mixture Gaussian Models In Human Cdna Sequences, G. Li, Tze-Yun Leong, Louxin Zhang

Research Collection School Of Computing and Information Systems

Translation initiation sites (TISs) are important signals in cDNA sequences. Many research efforts have tried to predict TISs in cDNA sequences. In this paper, we propose to use mixture Gaussian models for TIS prediction. Using both local features and some features generated from global measures, the proposed method predicts TISs with a sensitivity of 98 percent and a specificity of 93.6 percent. Our method outperforms many other existing methods in sensitivity while keeping specificity high. We attribute the improvement in sensitivity to the nature of the global features and the mixture Gaussian models. © 2005 IEEE.

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Descriptive Naming Of Context Data Providers, Norman H. Cohen, Paul Castro, Archan Misra Jul 2005

Descriptive Naming Of Context Data Providers, Norman H. Cohen, Paul Castro, Archan Misra

Research Collection School Of Computing and Information Systems

Much context data comes from mobile, transient, and unreliable sources. Such resources are best specified by descriptive names identifying what data is needed rather than which source is to provide it. The design of descriptive names has important consequences, but until now little attention has been focused on this problem. We propose a descriptive naming system for providers of context data that provides more flexibility and power than previous naming systems by classifying data providers into “provider kinds” that are organized in an evolving hierarchy of subkinds and superkinds. New provider kinds can be inserted in the hierarchy not only …

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Valuations Of Possible States (Vps): A Unifying Quantitative Framework For Evaluating Privacy In Collaboration, Rajiv T. Maheswaran, Jonathan Pearce, Pradeep Varakantham, Emma Bowring, Milind Tambe Jul 2005

Valuations Of Possible States (Vps): A Unifying Quantitative Framework For Evaluating Privacy In Collaboration, Rajiv T. Maheswaran, Jonathan Pearce, Pradeep Varakantham, Emma Bowring, Milind Tambe

Research Collection School Of Computing and Information Systems

For agents deployed in real-world settings, such as businesses, universities and research laboratories, it is critical that agents protect their individual users’ privacy when interacting with others entities. Indeed, privacy is recognized as a key motivating factor in design of several multiagent algorithms, such as distributed constraint optimization (DCOP) algorithms. Unfortunately, rigorous and general quantitative metrics for analysis and comparison of such multiagent algorithms with respect to privacy loss are lacking. This paper takes a key step towards developing a general quantitative model from which one can analyze and generate metrics of privacy loss by introducing the VPS (Valuations of …

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Strategic Assessment Of Information Security Maturity, Arcot Desai Narasimhalu, Dayasindhu Nagarajan, Raghavan Subramanian Jul 2005

Strategic Assessment Of Information Security Maturity, Arcot Desai Narasimhalu, Dayasindhu Nagarajan, Raghavan Subramanian

Research Collection School Of Computing and Information Systems

CXOs are becoming increasingly interested in the information security maturity of their enterprises. This paper presents a CXO dashboard that will allow better management of the information security resources in an enterprise.

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Exploiting Belief Bounds: Practical Pomdps For Personal Assistant Agents, Pradeep Varakantham, Rajiv Maheswaran, Milind Tambe Jul 2005

Exploiting Belief Bounds: Practical Pomdps For Personal Assistant Agents, Pradeep Varakantham, Rajiv Maheswaran, Milind Tambe

Research Collection School Of Computing and Information Systems

Agents or agent teams deployed to assist humans often face the challenges of monitoring the state of key processes in their environment (including the state of their human users themselves) and making periodic decisions based on such monitoring. POMDPs appear well suited to enable agents to address these challenges, given the uncertain environment and cost of actions, but optimal policy generation for POMDPs is computationally expensive. This paper introduces three key techniques to speedup POMDP policy generation that exploit the notion of progress or dynamics in personal assistant domains. Policy computation is restricted to the belief space polytope that remains …

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Middleware Architecture For Evaluation And Selection Of 3rd Party Web Services For Service Providers, Dipanjan Chakraborty, Suraj K. Jaiswal, Archan Misra, Amit A. Nanavati Jul 2005

Middleware Architecture For Evaluation And Selection Of 3rd Party Web Services For Service Providers, Dipanjan Chakraborty, Suraj K. Jaiswal, Archan Misra, Amit A. Nanavati

Research Collection School Of Computing and Information Systems

This paper presents an architecture to facilitate efficient evaluation and selection of 3rd party Web services for service providers. Most service provider architectures have primarily focused on providing Web service front ends to legacy systems, aggregating and delivering services via workflows. These architectures primarily considered static business contracts between the service provider and its (Web-service enabled) business partners. This approach makes these architectures inflexible to variations in business requirement, partners' performance and customer requirements. Our architecture provides a flexible means for service providers to optimize business performance. Based on the historical performance, extant context, and optimising business rules, the appropriate …

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Synthesis Of Distributed Processes From Scenario-Based Specifications, Jun Sun, Jin Song Dong Jul 2005

Synthesis Of Distributed Processes From Scenario-Based Specifications, Jun Sun, Jin Song Dong

Research Collection School Of Computing and Information Systems

Given a set of sequence diagrams, the problem of synthesis is of deciding whether there exists a satisfying object system and if so, synthesize one automatically. It is crucial in the development of complex systems, since sequence diagrams serve as the manifestation of use cases and if synthesizable they could lead directly to implementation. It is even more interesting (and harder) if the synthesized object system is distributed. In this paper, we propose a systematic way of synthesizing distributed processes from Live Sequence Charts. The basic idea is to first construct a CSP specification from the LSC specification, and then …

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Emd-Based Video Clip Retrieval By Many-To-Many Matching, Yuxin Peng, Chong-Wah Ngo Jul 2005

Emd-Based Video Clip Retrieval By Many-To-Many Matching, Yuxin Peng, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper presents a new approach for video clip retrieval based on Earth Mover's Distance (EMD). Instead of imposing one-to-one matching constraint as in [11, 14], our approach allows many-to-many matching methodology and is capable of tolerating errors due to video partitioning and various video editing effects. We formulate clip-based retrieval as a graph matching problem in two stages. In the first stage, to allow the matching between a query and a long video, an online clip segmentation algorithm is employed to rapidly locate candidate clips for similarity measure. In the second stage, a weighted graph is constructed to model …

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Multibiometrics Based On Palmprint And Handgeometry, Xiao-Yong Wei, Dan Xu, Chong-Wah Ngo Jul 2005

Multibiometrics Based On Palmprint And Handgeometry, Xiao-Yong Wei, Dan Xu, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper described our approach of multibiometrics in a single image. Firstly, a new method for capturing the key points of hand geometry is proposed. Then, we described our new method of palmprint feature extracting. By using projection transform and wavelet transform, this method considered both the global feature and local detail of a palmprint texture and proposed a new kind of palmprint feature. We also proposed a twice segmentation method for handgeometry feature extraction. In the processing of feature matching, we analyzed the weakness of the traditional Euclidian Square Norm method, and introduced an improved method. The experimental results …

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Co-Clustering Of Time-Evolving News Story With Transcript And Keyframe, Xiao Wu, Chong-Wah Ngo, Qing Li Jul 2005

Co-Clustering Of Time-Evolving News Story With Transcript And Keyframe, Xiao Wu, Chong-Wah Ngo, Qing Li

Research Collection School Of Computing and Information Systems

This paper presents techniques in clustering the same-topic news stories according to event themes. We model the relationship of stories with textual and visual concepts under the representation of bipartite graph. The textual and visual concepts are extracted respectively from speech transcripts and keyframes. Co-clustering algorithm is employed to exploit the duality of stories and textual-visual concepts based on spectral graph partitioning. Experimental results on TRECVID-2004 corpus show that the co-clustering of news stories with textual-visual concepts is significantly better than the co-clustering with either textual or visual concept alone.

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Hot Event Detection And Summarization By Graph Modeling And Matching, Yuxin Peng, Chong-Wah Ngo Jul 2005

Hot Event Detection And Summarization By Graph Modeling And Matching, Yuxin Peng, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper proposes a new approach for hot event detection and summarization of news videos. The approach is mainly based on two graph algorithms: optimal matching (OM) and normalized cut (NC). Initially, OM is employed to measure the visual similarity between all pairs of events under the one-to-one mapping constraint among video shots. Then, news events are represented as a complete weighted graph and NC is carried out to globally and optimally partition the graph into event clusters. Finally, based on the cluster size and globality of events, hot events can be automatically detected and selected as the summaries of …

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