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Sclope: An Algorithm For Clustering Data Streams Of Categorical Attributes, Kok-Leong Ong, Wenyuan Li, Wee-Keong Ng, Ee Peng Lim Sep 2004

Sclope: An Algorithm For Clustering Data Streams Of Categorical Attributes, Kok-Leong Ong, Wenyuan Li, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Clustering is a difficult problem especially when we consider the task in the context of a data stream of categorical attributes. In this paper, we propose SCLOPE, a novel algorithm based on CLOPE's intuitive observation about cluster histograms. Unlike CLOPE however, our algorithm is very fast and operates within the constraints of a data stream environment. In particular, we designed SCLOPE according to the recent CluStream framework. Our evaluation of SCLOPE shows very promising results. It consistently outperforms CLOPE in speed and scalability tests on our data sets while maintaining high cluster purity; it also supports cluster analysis that other …

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A Two-Level Framework For Coalition Formation Via Optimization And Agent Negotiation, Hoong Chuin Lau, Lei Zhang Sep 2004

A Two-Level Framework For Coalition Formation Via Optimization And Agent Negotiation, Hoong Chuin Lau, Lei Zhang

Research Collection School Of Computing and Information Systems

We present a two-level coalition formation approach based on a centralized optimization model on the upper level, and a distributed agent-negotiation model on the lower level. This approach allows us to balance agent self-interests against a high joint utility. Experimental results show that the two-level coalition formation mechanism will increase not only the overall utility of the coalition, but also the individual utility of most participating agents. The results also suggest it is better for the agents to be partially cooperative rather than either fully cooperative or self-interested in our setting.

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Robust Classification Of Event-Related Potential For Brain-Computer Interface, Manoj Thulasidas Sep 2004

Robust Classification Of Event-Related Potential For Brain-Computer Interface, Manoj Thulasidas

Research Collection School Of Computing and Information Systems

We report the implementation of a text input application (speller) based on the P300 event related potential. We obtain high accuracies by using an SVM classifier and a novel feature. These techniques enable us to maintain fast performance without sacrificing the accuracy, thus making the speller usable in an online mode. In order to further improve the usability, we perform various studies on the data with a view to minimizing the training time required. We present data collected from nine healthy subjects, along with the high accuracies (of the order of 95% or more) measured online. We show that the …

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Towards Personalised Web Intelligence, Ah-Hwee Tan, Hwee-Leng Ong, Hong Pan, Jamie Ng, Qiu-Xiang Li Sep 2004

Towards Personalised Web Intelligence, Ah-Hwee Tan, Hwee-Leng Ong, Hong Pan, Jamie Ng, Qiu-Xiang Li

Research Collection School Of Computing and Information Systems

The Flexible Organizer for Competitive Intelligence (FOCI) is a personalised web intelligence system that provides an integrated platform for gathering, organising, tracking, and disseminating competitive information on the web. FOCI builds personalised information portfolios through a novel method called User-Configurable Clustering, which allows a user to personalise his/her portfolios in terms of the content as well as the organisational structure. This paper outlines the key challenges we face in personalised information management and gives a detailed account of FOCI’s underlying personalisation mechanism. For a quantitative evaluation of the system’s performance, we propose a set of performance indices based on information …

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Optimizing Proportionally Fair Prices, Laura Wynter Sep 2004

Optimizing Proportionally Fair Prices, Laura Wynter

Research Collection School Of Computing and Information Systems

We demonstrate the non-uniqueness of proportional fairness prices, and show that the model of Kelly et al. [9] falls into the category of models that can be generalized to allow optimization of the link prices, with a view toward profit maximization. However, through this framework, we also show that the total revenue that can be obtained through proportional fairness pricing on a network is unique.

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Future Fiscal And Budgetary Shocks, Hian Teck Hoon, Edmund S. Phelps Sep 2004

Future Fiscal And Budgetary Shocks, Hian Teck Hoon, Edmund S. Phelps

Research Collection School Of Economics

We study here the effects of future tax and budgetary shocks on present levels of economic activity and real interest rates in a nonmonetary and possibly non-Ricardian economy. The paper first takes up an (unanticipated) temporary tax cut to be effective on a given future date—a delayed debt bomb. The sudden prospect of this future-dated shock causes at once a drop in the (unit) value placed on the firms’ business asset, the customer, and accordingly on the price of shares—with the result that the hourly wage, hours worked and GDP drop in tandem. This paradox of reduced activity through announcement …

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Treaties, Time Limits And Treasure Trove: The Legal Protection Of Cultural Objects In Singapore, Jack Tsen-Ta Lee Sep 2004

Treaties, Time Limits And Treasure Trove: The Legal Protection Of Cultural Objects In Singapore, Jack Tsen-Ta Lee

Research Collection Yong Pung How School Of Law

This article considers the extent to which civil and criminal law in Singapore deters the unlawful removal of cultural objects from the possession of private owners, art galleries and museums, or from archaeological sites, and provides redress to victims. Given Singapore's position as the crossroads of Asia, the law must be able to cope with the flow of objects in and out of the country. The law is currently deficient as it is not tailored to deal with issues concerning cultural heritage, and needs to be reformed in several respects. There are sound reasons for a modern State like Singapore …

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A Spectroscopy Of Texts For Effective Clustering, Wenyuan Li, Wee-Keong Ng, Kok-Leong Ong, Ee Peng Lim Sep 2004

A Spectroscopy Of Texts For Effective Clustering, Wenyuan Li, Wee-Keong Ng, Kok-Leong Ong, Ee Peng Lim

Research Collection School Of Computing and Information Systems

For many clustering algorithms, such as k-means, EM, and CLOPE, there is usually a requirement to set some parameters. Often, these parameters directly or indirectly control the number of clusters to return. In the presence of different data characteristics and analysis contexts, it is often difficult for the user to estimate the number of clusters in the data set. This is especially true in text collections such as Web documents, images or biological data. The fundamental question this paper addresses is: ldquoHow can we effectively estimate the natural number of clusters in a given text collection?rdquo. We propose to use …

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A Development Framework For Rapid Metaheuristics Hybridization, Hoong Chuin Lau, M. K. Lim, W. C. Wan, S. Halim Sep 2004

A Development Framework For Rapid Metaheuristics Hybridization, Hoong Chuin Lau, M. K. Lim, W. C. Wan, S. Halim

Research Collection School Of Computing and Information Systems

While meta-heuristics are effective for solving large-scale combinatorial optimization problems, they result from time-consuming trial-and-error algorithm design tailored to specific problems. For this reason, a software tool for rapid prototyping of algorithms would save considerable resources. This work presents a generic software framework that reduces development time through abstract classes and software reuse, and more importantly, aids design with support of user-defined strategies and hybridization of meta-heuristics. Most interestingly, we propose a novel way of redefining hybridization with the use of the "request and response" metaphor, which form an abstract concept for hybridization. Different hybridization schemes can now be formed …

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Shared-Storage Auction Ensures Data Availability, Hady W. Lauw, Siu-Cheung Hui, Edmund M. K. Lai Sep 2004

Shared-Storage Auction Ensures Data Availability, Hady W. Lauw, Siu-Cheung Hui, Edmund M. K. Lai

Research Collection School Of Computing and Information Systems

Most current e-auction systems are based on the client-server architecture. Such centralized systems provide a single point of failure and control. In contrast, peer-to-peer systems permit distributed control and minimize individual node and link failures' impact on the system. The shared-storage-based auction model described decentralizes services among peers to share the required processing load and aggregates peers' resources for common use. The model is based on the principles of local computation at each peer, direct inter-peer communication, and a shared storage space.

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A Qualitative Investigation On Consumer Trust In Mobile Commerce, Keng Siau, Hong Sheng, Fiona Fui-Hoon Nah, Sidney A. Davis Sep 2004

A Qualitative Investigation On Consumer Trust In Mobile Commerce, Keng Siau, Hong Sheng, Fiona Fui-Hoon Nah, Sidney A. Davis

Research Collection School Of Computing and Information Systems

Mobile commerce represents a significant development in e-commerce, offering accessibility, ubiquity, mobility, and localisation to users. Despite the potential of mobile commerce, trust is a major obstacle in its adoption and development. Many consumers feel uncomfortable with the idea of conducting commerce over wireless, hand-held devices. The focus of this research is to understand trust in mobile commerce and to identify factors that are important for trust development. The research builds on Siau and Shen's framework which depicts two key factors influencing trust in mobile commerce. This research not only validates and expands on the existing framework, but also provides …

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Proxy Signature Scheme With Multiple Original Signers For Wireless E-Commerce Applications, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng Sep 2004

Proxy Signature Scheme With Multiple Original Signers For Wireless E-Commerce Applications, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

In a proxy signature scheme, a user delegates his/her signing capability to another user in such a way that the latter can sign messages on behalf of the former. We propose an efficient and secure proxy signature scheme with multiple original signers. Our scheme is suitable for wireless electronic commerce applications, since the overheads of computation and communication are low. As an example, we present an electronic air ticket booking scheme for wireless customers.

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On The Security Of The Lee-Hwang Group-Oriented Undeniable Signature Schemes, Guilin Wang, Jianying Zhou, Robert H. Deng Sep 2004

On The Security Of The Lee-Hwang Group-Oriented Undeniable Signature Schemes, Guilin Wang, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

Undeniable signature is an intriguing concept introduced by Chaum and van Antwerpen at Crypto89. In 1999, Lee and Hwang presented two group-oriented undeniable signature schemes with a trusted center. Their schemes are natural generalizations of Chaums zero knowledge undeniable signature scheme proposed in 1990. However, we find that the Lee-Hwang schemes are insecure. In this paper, we demonstrate five effective attacks on their schemes: four of them are insider universal forgeries, in which one dishonest member (maybe colluding with a verifier) can get a valid signature on any chosen massage, and another attack allows a dishonest member to prevent honest …

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Security Analysis Of Two Signcryption Schemes, Guilin Wang, Robert H. Deng, Dongjin Kwak, Sangjae Moon Sep 2004

Security Analysis Of Two Signcryption Schemes, Guilin Wang, Robert H. Deng, Dongjin Kwak, Sangjae Moon

Research Collection School Of Computing and Information Systems

Signcryption is a new cryptographic primitive that performs signing and encryption simultaneously, at a cost significantly lower than that required by the traditional signature-then-encryption approach. In this paper, we present a security analysis of two such schemes: the Huang-Chang convertible signcryption scheme, and the Kwak-Moon group signcryption scheme. Our results show that both schemes are insecure. Specifically, the Huang-Chang scheme fails to provide confidentiality, while the Kwak-Moon scheme does not satisfy the properties of unforgeability, coalition-resistance, and traceability.

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Deformable Geometry Model Matching By Topological And Geometric Signatures, Kwok-Leung Tam, Rynson W.H. Law, Chong-Wah Ngo Aug 2004

Deformable Geometry Model Matching By Topological And Geometric Signatures, Kwok-Leung Tam, Rynson W.H. Law, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

In this paper, we present a novel method for efficient 3D model comparison. The method matches highly deformed models by comparing topological and geometric features. First, we propose “Bi-directional LSD analysis” to locate reliable topological points and rings. Second, based on these points and rings, a set of bounded regions are extracted as topological features. Third, for each bounded region, we capture additional spatial location, curvature and area distribution as geometric data. Fourth, to model the topological importance of each bounded region, we capture its effective area as weight. By using “Earth Mover Distance” as a distance measure between two …

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Group-Based Relevance Feedback With Support Vector Machine Ensembles, Steven C. H. Hoi, Michael R. Lyu Aug 2004

Group-Based Relevance Feedback With Support Vector Machine Ensembles, Steven C. H. Hoi, Michael R. Lyu

Research Collection School Of Computing and Information Systems

Support vector machines (SVMs) have become one of the most promising techniques for relevance feedback in content-based image retrieval (CBIR). Typical SVM-based relevance feedback techniquessimply apply the strict binary classifications: positive (relevant) class and negative (irrelevant) class. However, in a real-world relevance feedback task, it is more reasonable and practical to assume the data come from multiple positive classes and one negative class. In order to formulate an effective relevance feedback algorithm, we propose a novel group-based relevance feedback scheme constructed with the SVM ensembles technique. Experiments are conducted to evaluate the performance of our proposed scheme and the traditional …

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High Accuracy Classification Of Eeg Signal, Wenjie Xu, Cuitai Guan, Chng Eng Siong, S. Ranganatha, Manoj Thulasidas, Jiankang Wu Aug 2004

High Accuracy Classification Of Eeg Signal, Wenjie Xu, Cuitai Guan, Chng Eng Siong, S. Ranganatha, Manoj Thulasidas, Jiankang Wu

Research Collection School Of Computing and Information Systems

Improving classification accuracy is a key issue to advancing brain computer interface (BCI) research from laboratory to real world applications. This article presents a high accuracy EEC signal classification method using single trial EEC signal to detect left and right finger movement. We apply an optimal temporal filter to remove irrelevant signal and subsequently extract key features from spatial patterns of EEG signal to perform classification. Specifically, the proposed method transforms the original EEG signal into a spatial pattern and applies the RBF feature selection method to generate robust feature. Classification is performed by the SVM and our experimental result …

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Investigating Deception In Cyberspace, Holtjona Galanxhi, Fiona Fui-Hoon Nah Aug 2004

Investigating Deception In Cyberspace, Holtjona Galanxhi, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

The use of anthropomorphic avatars provides Internet users the opportunity and freedom to present their desired identity. As cyberspace becomes a heaven for deceptive behavior, human-computer interaction research will need to be carried out to study and understand these deceptive behaviors. The objective of this research is to investigate the behavior of deceivers and truthtellers in the cyberspace environment and to examine how their intention to deceive may influence the choice of their avatars. The effect of using avatars to support communication will also be studied. This research provides insights on communication and trust issues in avatar environments.

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Values Of Mobile Technology In Education, Fiona Fui-Hoon Nah, Keng Siau, H. Sheng Aug 2004

Values Of Mobile Technology In Education, Fiona Fui-Hoon Nah, Keng Siau, H. Sheng

Research Collection School Of Computing and Information Systems

Mobile technology shows promise in supporting and improving education and its delivery. Coupled with the use of mobile devices and software/hardware solutions that make it possible to access educational content, students can be exposed to new educational experience. Applications of mobile technology in education can provide many benefits including greater flexibility, more available education resources, as well as greater convenience, accessibility and responsiveness. As a new phenomenon that will be widely used and adopted in the years to come, the values of mobile technology in education should be better understood and researched. This research outlines our empirical study to examine …

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Rating Information Security Maturity, Arcot Desai Narasimhalu, Nagarajan Dayasindhu Aug 2004

Rating Information Security Maturity, Arcot Desai Narasimhalu, Nagarajan Dayasindhu

Research Collection School Of Computing and Information Systems

Most CEOs have difficulty relating to the information security investments in their companies. This article presents a summary of a the information security maturity model that the CEOs could use to determine the desired level of investments into information security infrastructure, tools and applications.

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Exploiting Information Theory For Adaptive Mobility And Resource Management In Future Cellular Networks, Abhishek Roy, Sajal K. Das, Archan Misra Aug 2004

Exploiting Information Theory For Adaptive Mobility And Resource Management In Future Cellular Networks, Abhishek Roy, Sajal K. Das, Archan Misra

Research Collection School Of Computing and Information Systems

We utilize tools from information theory to develop adaptive algorithms for two key problems in cellular networks: location tracking and resource management. The use of information theory is motivated by the fundamental observation that overheads in many aspects of mobile computing can be traced to the randomness or uncertainty in an individual user's movement behavior. We present a model-independent information-theoretic approach for estimating and managing this uncertainty, and relate it to the entropy or information content of the user's movement process. Information-theoretic mobility management algorithms are very simple, yet reduce overhead by ∼80 percent in simulated scenarios by optimally adapting …

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Ltam: A Location-Temporal Authorization Model, Hai Yu, Ee Peng Lim Aug 2004

Ltam: A Location-Temporal Authorization Model, Hai Yu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

This paper describes an authorization model for specifying access privileges of users who make requests to access a set of locations in a building or more generally a physical or virtual infrastructure. In the model, primitive locations can be grouped into composite locations and the connectivities among locations are represented in a multilevel location graph. Authorizations are defined with temporal constraints on the time to enter and leave a location and constraints on the number of times users can access a location. Access control enforcement is conducted by monitoring user movement and checking access requests against an authorization database. The …

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Theoretical And Practical Complexity Of Uml, J. Erickson, Keng Siau Aug 2004

Theoretical And Practical Complexity Of Uml, J. Erickson, Keng Siau

Research Collection School Of Computing and Information Systems

Systems have become increasingly complex, and as a result development methods have become more complex as well. The unified modeling language (UML) has been criticized for the often cited and sometimes over-whelming complexity it presents to its users, and those seeking to learn to use it. Using Rossi and Brinkkemper’s (1996) complexity metrics, Siau and Cao (2001) completed a complexity analysis of UML and 36 other modeling techniques, finding that UML is indeed more complex than other techniques. Siau, Erickson and Lee (2002) proposed that Rossi and Brinkkemper’s metrics present the theoretical maximum complexity, known as theoretical complexity. This is …

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Sa&D And Database: Should We Be Researching What We Are Teaching?, Jeffrey B. Parson, Akhilesh. Bajaj, Dinesh Batra, Alan Hevner, Keng Siau Aug 2004

Sa&D And Database: Should We Be Researching What We Are Teaching?, Jeffrey B. Parson, Akhilesh. Bajaj, Dinesh Batra, Alan Hevner, Keng Siau

Research Collection School Of Computing and Information Systems

The panel will examine the reasons for the mismatch between SA&D and database teaching and research. The implication of this mismatch on the MIS academic and practitioner communities will also be discussed and debated.

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Ica-Fx Features For Classification Of Singing Voice And Instrumental Sound, Tat-Wan Leung, Chong-Wah Ngo, Rynson W. H Lau Aug 2004

Ica-Fx Features For Classification Of Singing Voice And Instrumental Sound, Tat-Wan Leung, Chong-Wah Ngo, Rynson W. H Lau

Research Collection School Of Computing and Information Systems

This paper describes a new approach in locating the segments of singing voice in pop musical songs. Initially, GLR distance measure is employed to temporally detect the boundaries of singing voices and instrumental sounds. ICAFX is then adopted to extract the independent components of acoustic features for SVM classification. Experimental results indicate that ICA-FX can improve the classification performance by significantly reducing the independent components that are not related to class label information.

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Graph Based Image Matching, Hui Jiang, Chong-Wah Ngo Aug 2004

Graph Based Image Matching, Hui Jiang, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Given two or more images, we can define different but related problems on pattern matching such as image registration, pattern detection and localization, and common pattern discovery. These problems have different levels of purpose and difficulties, as a result, often associate with different solutions. In this paper, we propose a novel approach to solve these problems under a unified framework based on graph matching. We first split the images into small blocks and represent each block as a node in a bipartite graph. A maximum weighted bipartite graph matching algorithm is then employed in an iterative way to find the …

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Novel Seed Selection For Multiple Objects Detection And Tracking, Zailiang Pan, Chong-Wah Ngo Aug 2004

Novel Seed Selection For Multiple Objects Detection And Tracking, Zailiang Pan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper proposes a unified approach for initializing, detecting and tracking of multiple moving objects. Object initialization is achieved through novel seed selection which is adaptively activated, depending on the quality of tracking, to select the best possible frames along the temporal direction for object detection. EM algorithm is then employed to robustly segment and detect multiple objects in a selected frame. Each detected object is represented by an appearance-based model and mean shift tracking procedure is adopted to rapidly and effectively track the target objects.

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Gesture Tracking And Recognition For Lecture Video Editing, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong Aug 2004

Gesture Tracking And Recognition For Lecture Video Editing, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

This paper presents a gesture based driven approach for video editing. Given a lecture video, we adopt novel approaches to automatically detect and synchronize its content with electronic slides. The gestures in each synchronized topic (or shot) are then tracked and recognized continuously. By registering shots and slides and recovering their transformation, the regions where the gestures take place can be known. Based on the recognized gestures and their registered positions, the information in slides can be seamlessly extracted, not only to assist video editing, but also to enhance the quality of original lecture video.

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Packet-Loss Resilient Coding Scheme With Only Xor Operations, Gui Liang Feng, Robert H. Deng, Feng Bao Aug 2004

Packet-Loss Resilient Coding Scheme With Only Xor Operations, Gui Liang Feng, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

Application of forward error correction to recover lost packets in higher layers of communication networks is receiving increasing attention. Most of the previous proposals for packet loss recovery use symbol-oriented Reed-Solomon codes operating in symbol erasure-correction mode. A Reed-Solomon code is optimal in the sense that it is maximal distance separable; however, the decoding speed of a Reed-Solomon code is slow since it involves operations over GF(2m) using lookup tables. A packet-oriented (n, k)/(m, l) packet-loss resilient code based on an (n, k) Reed-Solomon code over GF(2m) is given. The code accepts k-packet information sequences and encodes them into n-packet …

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Transport Logistics Planning With Service-Level Constraints, Hoong Chuin Lau, K. M. Ng, Xintao Wu Jul 2004

Transport Logistics Planning With Service-Level Constraints, Hoong Chuin Lau, K. M. Ng, Xintao Wu

Research Collection School Of Computing and Information Systems

In this paper, we study a logistics problem arising in military transport planning. A military organization operates a large fleet of vehicles in a depot to serve the requests of various operational units. Each request has a fixed start and end time, and is served by a prescribed number of vehicles. We address the following two problems: (1) how many vehicles are at least needed to meet a given service level of requests; and (2) suppose we allow each request to shift its start time by a constant duration, call all the requests be met? A Niche genetic algorithm, together …

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