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Articles 8641 - 8670 of 9441

Full-Text Articles in Physical Sciences and Mathematics

Transition Rule Elicitation Methods For Urban Cellular Automata Models, Junfeng Jiao, Luc Boerboom Jan 2006

Transition Rule Elicitation Methods For Urban Cellular Automata Models, Junfeng Jiao, Luc Boerboom

Research Collection College of Integrative Studies

In this chapter, transition rules used in urban CA models are reviewed and classified into two categories: transition potential rules and conflict resolution rules. Then, four widely used rule elicitation methods: Regression analysis, Artificial Neural network (ANN), Visual calibration, and Analytical Hierarchy Processing – Multi Criteria Evaluation (AHP-MCE) are discussed. Most of these methods are data driven methods and can be used to elicit the transition potential rules in the urban CA models. In the following, three possible rule elicitation methods: Interview, Document analysis, and Card sorting are explained and demonstrated. These three methods are driven by knowledge and can …

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Visualization For Analyzing Trajectory-Based Metaheuristic Search Algorithms, Steven Halim, Roland H. C. Yap, Hoong Chuin Lau Jan 2006

Visualization For Analyzing Trajectory-Based Metaheuristic Search Algorithms, Steven Halim, Roland H. C. Yap, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

No abstract provided.

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Efficient Mining Of Group Patterns From User Movement Data, Yida Wang, Ee Peng Lim, San-Yih Hwang Jan 2006

Efficient Mining Of Group Patterns From User Movement Data, Yida Wang, Ee Peng Lim, San-Yih Hwang

Research Collection School Of Computing and Information Systems

In this paper, we present a new approach to derive groupings of mobile users based on their movement data. We assume that the user movement data are collected by logging location data emitted from mobile devices tracking users. We formally define group pattern as a group of users that are within a distance threshold from one another for at least a minimum duration. To mine group patterns, we first propose two algorithms, namely AGP and VG-growth. In our first set of experiments, it is shown when both the number of users and logging duration are large, AGP and VG-growth are …

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Using Social Development Lenses To Understand E-Government Development, Keng Siau, Y. Long Jan 2006

Using Social Development Lenses To Understand E-Government Development, Keng Siau, Y. Long

Research Collection School Of Computing and Information Systems

As governments at different levels and all around the world are increasingly using the Web to enhance and improve their services, understanding e-government development and exploring factors that affect e-government development have become important research topics. The purpose of this research is to investigate factors explaining e-government development in terms of social development lenses. Based on growth and regional development theories, the paper hypothesizes that income level, development status, and region are three factors that differentiate e- government development in countries. Group comparison tests are conducted using secondary data from the United Nations and the United Nations Development Programme. The …

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Using Cognitive Mapping Techniques To Supplement Uml And Up In Information Requirements Determination, Keng Siau, Tan Xin Jan 2006

Using Cognitive Mapping Techniques To Supplement Uml And Up In Information Requirements Determination, Keng Siau, Tan Xin

Research Collection School Of Computing and Information Systems

Information requirements determination is a critical task in system development projects. Many human issues may hinder the efforts to accurately capture and clearly understand users' information requirements. In this paper, we review the cognitive underpinnings of some human issues, which are discussed in existing literature and relevant to information requirements determination. We then propose the use of cognitive mapping techniques in the process of information requirements determination. Three widely used cognitive mapping techniques - causal mapping, semantic mapping, and concept mapping – are briefly introduced in this article. A case is used to illustrate how to use these cognitive mapping …

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E-Healthcare In Abc County Health Department (Abcchd): Trade-Offs Analysis And Evaluation, Keng Siau, Hwee-Joo Kam Jan 2006

E-Healthcare In Abc County Health Department (Abcchd): Trade-Offs Analysis And Evaluation, Keng Siau, Hwee-Joo Kam

Research Collection School Of Computing and Information Systems

The issue of privacy stirred a tumultuous uproar when the ABC County Health Department (ABCCHD) was planning for an e-Healthcare system that utilized information technology to streamline the administration process of patients. ABCCHD had hired a software vendor, Info-Health, a company that specialized in information system development for the healthcare industry to help in the project. The privacy of patients with Sexually Transmitted Diseases/Human Immunity System was a thorny issue in the implementation of the e-Healthcare system. A trade-off between privacy and cost was discussed and debated. Three alternatives, with varying degrees of privacy and cost, were considered.

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Systems Analysis & Design: An Essential Part Of Is Education, Albert L. Harris, Michael Lang, Briony J. Oates, Keng Siau Jan 2006

Systems Analysis & Design: An Essential Part Of Is Education, Albert L. Harris, Michael Lang, Briony J. Oates, Keng Siau

Research Collection School Of Computing and Information Systems

Systems analysis and design has been as critical building block in Information Systems (IS) education since the inception of the IS major. Whether it is taught using the traditional or "structured approach or the object-oriented approach, it exposes students to the different methods, tools, and techniques used in developing new systems, develops students analytical and problem-solving skills, teaches fact-finding and data gathering techniques, and provides teamwork skills. All of these are valuable skills for systems analysts. This paper introduces the reader of this special issue on systems analysis and design education to the issue, discusses the two approaches to teaching …

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The Roles Of Digital Libraries In Teaching And Learning Geography, Chew-Hung Chang, John Hedberg, Tiong-Sa Teh, Ee Peng Lim Jan 2006

The Roles Of Digital Libraries In Teaching And Learning Geography, Chew-Hung Chang, John Hedberg, Tiong-Sa Teh, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Adopting a problem-centred approach helps students to learn Geography more effectively as they are able to identify and generalize about where different resources or activities are spatially located and they learn to associate certain patterns and processes with geographical changes. In an era where web-based student-centred inquiry is gaining popularity as a mode of learning Geography, the role of digital libraries as delivery trucks (in Clark’s terminology, 1983) needs to be better understood. An obvious affordance of the digital library is that it organizes information around themes for problems to be solved. This paper describes a developmental project to build …

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Multiagent Teamwork: Hybrid Approaches, Praveen Paruchuri, Emma Bowring, Ranjit Nair, Jonathan Pearce, Nathan Schurr, Milind Tambe, Pradeep Varakantham Jan 2006

Multiagent Teamwork: Hybrid Approaches, Praveen Paruchuri, Emma Bowring, Ranjit Nair, Jonathan Pearce, Nathan Schurr, Milind Tambe, Pradeep Varakantham

Research Collection School Of Computing and Information Systems

Today within the multiagent community, we see at least four competing methods to building multiagent systems: beliefdesireintention (BDI), distributed constraint optimization (DCOP), distributed POMDPs, and auctions or game-theoretic methods. While there is exciting progress within each approach, there is a lack of cross-cutting research. This article highlights the various hybrid techniques for multiagent teamwork developed by the teamcore group. In particular, for the past decade, the TEAMCORE research group has focused on building agent teams in complex, dynamic domains. While our early work was inspired by BDI, we will present an overview of recent research that uses DCOPs and distributed …

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Grid-Partition Index: A Hybrid Approach To Nearest-Neighbor Queries In Wireless Location-Based Services, Baihua Zheng, Jianliang Xu, Wang-Chien Lee, Dik Lun Lee Jan 2006

Grid-Partition Index: A Hybrid Approach To Nearest-Neighbor Queries In Wireless Location-Based Services, Baihua Zheng, Jianliang Xu, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Traditional nearest-neighbor (NN) search is based on two basic indexing approaches: object-based indexing and solution-based indexing. The former is constructed based on the locations of data objects: using some distance heuristics on object locations. The latter is built on a precomputed solution space. Thus, NN queries can be reduced to and processed as simple point queries in this solution space. Both approaches exhibit some disadvantages, especially when employed for wireless data broadcast in mobile computing environments. In this paper, we introduce a new index method, called the grid-partition index, to support NN search in both ondemand access and periodic broadcast …

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Towards Better Quality Specification Miners, David Lo, Siau-Cheng Khoo Jan 2006

Towards Better Quality Specification Miners, David Lo, Siau-Cheng Khoo

Research Collection School Of Computing and Information Systems

Softwares are often built without specification. Tools to automatically extract specification from software are needed and many techniques have been proposed. One type of these specifications – temporal API specification – is often specified in the form of automaton (i.e., FSA/PFSA). There have been many work on mining software temporal specification using dynamic analysis techniques; i.e., analysis of software program traces. Unfortunately, the issues of scalability, robustness and accuracy of these techniques have not been comprehensively addressed. In this paper, we describe a framework that enables assessments of the performance of a specification miner in generating temporal specification of software …

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In-Network Join Processing For Sensor Networks, Hai Yu, Ee Peng Lim, Jun Zhang Jan 2006

In-Network Join Processing For Sensor Networks, Hai Yu, Ee Peng Lim, Jun Zhang

Research Collection School Of Computing and Information Systems

Recent advances in hardware and wireless technologies have led to sensor networks consisting of large number of sensors capable of gathering and processing data collectively. Query processing on these sensor networks has to consider various inherent constraints. While simple queries such as select and aggregate queries in wireless sensor networks have been addressed in the literature, the processing of join queries in sensor networks remains to be investigated. In this paper, we present a synopsis join strategy for evaluating join queries in sensor networks with communication efficiency. In this strategy, instead of directly joining two relations distributed in a sensor …

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A Grapheme To Phoneme Converter For Standard Malay, Haizhou Li, Mahani Aljunied, Boon Seong Teoh Dec 2005

A Grapheme To Phoneme Converter For Standard Malay, Haizhou Li, Mahani Aljunied, Boon Seong Teoh

Research Collection Lee Kong Chian School Of Business

This paper describes the process of creating a grapheme-to-phoneme (G2P) converter for Standard Malay (SM). A fundamental step to building TTS and ASR engines, is to build a good G2P system that can automatically generate accurate phonemic representations for words. Our goal is to generate phonemes that reflect real speech, thereby facilitating more accurate phoneme alignment with actual waveforms (obtained from voice-data collection), keeping human intervention to the minimum. Here we discuss the key areas in SM that require considerable phonemic alterations including letter elisions, consonant insertions, multiple ways of uttering a letter/diagraph – areas that any good G2P system …

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Sequential Aggregate Signatures Working Over Independent Homomorphic Trapdoor One-Way Permutation Domains, Huafei Zhu, Feng Bao, Robert H. Deng Dec 2005

Sequential Aggregate Signatures Working Over Independent Homomorphic Trapdoor One-Way Permutation Domains, Huafei Zhu, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

The contribution of this paper has two folds. In the first fold, we propose a generic construction of sequential aggregate signatures from families of certificated trapdoor one-way permutations. We show that our construction is provably secure in the random oracle model assuming that the underlying homomorphic permutations are trapdoor one-way. Compared to Lysyanskaya et al’s generic construction that is constructed from a trapdoor one-way permutation family working over the same domain [16], our scheme works over independent trapdoor one-way permutation domains. The flexible choice of the underlying permutation domains benefits our scheme to its applications in the real world where …

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Improving The Quality Of Conceptual Modeling Using Cognitive Mapping Techniques, Keng Siau, X. Tan Dec 2005

Improving The Quality Of Conceptual Modeling Using Cognitive Mapping Techniques, Keng Siau, X. Tan

Research Collection School Of Computing and Information Systems

Conceptual modeling involves the understanding and communication between system analysts and end-users. Many factors may affect the quality of conceptual modeling processes as well as the models per se. Human cognition plays a pivotal role in understanding these factors and cognitive mapping techniques are effective tools to elicit and represent human cognition. In this paper, we look at the use of cognitive mapping techniques to improve the quality of conceptual modeling. We review frameworks on quality in conceptual modeling and examine the role of human cognition in conceptual modeling. The paper also discusses how human cognition is related to quality …

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Tailored Watermarking Schemes For Authentication Of Electronic Clinical Atlases, Feng Bao, Robert H. Deng, Beng-Chin Ooi, Yanjiang Yang Dec 2005

Tailored Watermarking Schemes For Authentication Of Electronic Clinical Atlases, Feng Bao, Robert H. Deng, Beng-Chin Ooi, Yanjiang Yang

Research Collection School Of Computing and Information Systems

It is accepted that digital watermarking is quite relevant in medical imaging. However, due to the special nature of clinical practice, it is often required that watermarking not introduce irreversible distortions to medical images. The electronic clinical atlas has such a need of "lossless" watermarking. We present two tailored reversible watermarking schemes for the clinical atlas by exploiting its inherent characteristics. We have implemented the schemes and our experimental results look very promising.

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Integration Of Probabilistic Graphic Models For Decision Support, Jiang C., Poh K., Tze-Yun Leong Dec 2005

Integration Of Probabilistic Graphic Models For Decision Support, Jiang C., Poh K., Tze-Yun Leong

Research Collection School Of Computing and Information Systems

It is a frequently encountered problem that new knowledge arrived when making decisions in a dynamic world. Usually, domain experts cannot afford enough time and knowledge to effectively assess and combine both qualitative and quantitative information in these models. Existing approaches can solve only one of two tasks instead of both. We propose a four-step algorithm to integrate multiple probabilistic graphic models, which can effectively update existing models with newly acquired models. In this algorithm, the qualitative part of model integration is performed first, followed by the quantitative combination. We illustrate our method with an example of combining three models. …

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A Generic Object-Oriented Tabu Search Framework, Hoong Chuin Lau, Xiaomin Jia, Wee Chong Wan Dec 2005

A Generic Object-Oriented Tabu Search Framework, Hoong Chuin Lau, Xiaomin Jia, Wee Chong Wan

Research Collection School Of Computing and Information Systems

Presently, most tabu search designers devise their applications without considering the potential of design and code reuse, which consequently prolong the development of subsequent applications. In this paper, we propose a software solution known as Tabu Search Framework (TSF), which is a generic C++ software framework for tabu search implementation. The framework excels in code recycling through the use of a well- designed set of generic abstract classes that clearly define their collaborative roles in the algorithm. Additionally, the framework incorporates a centralized process and control mechanism that enhances the search with intelligence. This results in a generic framework that …

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Webarc: Website Archival Using A Structured Approach, Ee Peng Lim, Maria Marissa Dec 2005

Webarc: Website Archival Using A Structured Approach, Ee Peng Lim, Maria Marissa

Research Collection School Of Computing and Information Systems

Website archival refers to the task of monitoring and storing snapshots of website(s) for future retrieval and analysis. This task is particularly important for websites that have content changing over time with older information constantly overwritten by newer one. In this paper, we propose WEBARC as a set of software tools to allow users to construct a logical structure for a website to be archived. Classifiers are trained to. determine relevant web pages and their categories, and subsequently used in website downloading. The archival schedule can be specified and executed by a scheduler. A website viewer is also developed to …

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New Efficient Mds Array Codes For Raid Part Ii: Rabin-Like Codes For Tolerating Multiple (>=4) Disk Failures, Gui-Liang Feng, Robert H. Deng, Feng Bao Dec 2005

New Efficient Mds Array Codes For Raid Part Ii: Rabin-Like Codes For Tolerating Multiple (>=4) Disk Failures, Gui-Liang Feng, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

A new class of Binary Maximum Distance Separable (MDS) array codes which are based on circular permutation matrices are introduced in this paper. These array codes are used for tolerating multiple (greater than or equal to 4) disk failures in Redundant Arrays of Inexpensive Disks (RAID) architecture. The size of the information part is m \times n, where n is the number of information disks and (m+1) is a prime integer; the size of the parity-check part is m \times r, the minimum distance is r+1, and the number of parity-check disks is r. In practical applications, m can be …

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Matrix: Adaptive Middleware For Distributed Multiplayer Games, Rajesh Krishna Balan, Maria Ebling, Paul Castro, Archan Misra Dec 2005

Matrix: Adaptive Middleware For Distributed Multiplayer Games, Rajesh Krishna Balan, Maria Ebling, Paul Castro, Archan Misra

Research Collection School Of Computing and Information Systems

Building a distributed middleware infrastructure that provides the low latency required for massively multiplayer games while still maintaining consistency is non-trivial. Previous attempts have used static partitioning or client-based peer-to-peer techniques that do not scale well to a large number of players, perform poorly under dynamic workloads or hotspots, and impose significant programming burdens on game developers. We show that it is possible to build a scalable distributed system, called Matrix, that is easily usable by game developers. We show experimentally that Matrix provides good performance, especially when hotspots occur.

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Giving Users The Steering Wheel For Guiding Resource-Adaptive Systems, Joao Sousa, Rajesh Krishna Balan, Vahe Poladian, David Garlan, Mahadev Satyanarayanan Dec 2005

Giving Users The Steering Wheel For Guiding Resource-Adaptive Systems, Joao Sousa, Rajesh Krishna Balan, Vahe Poladian, David Garlan, Mahadev Satyanarayanan

Research Collection School Of Computing and Information Systems

Addressing resource variation plays an increasingly important role in engineering today's software systems. Research in resource-adaptive applications takes an important step towards addressing this problem. However, existing solutions stop short of addressing the fact that different user tasks often have specific goals of quality of service, and that such goals often entail multiple aspects of quality of service. This paper presents a framework for engineering software systems capable of adapting to resource variations in ways that are specific to the quality goals of each user task. For that, users are empowered to specify their task-specific preferences with respect to multiple …

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A Block Oriented Fingerprinting Scheme In Relational Database, Siyuan Liu, Shuhong Wang, Robert H. Deng, Weizhong Shao Dec 2005

A Block Oriented Fingerprinting Scheme In Relational Database, Siyuan Liu, Shuhong Wang, Robert H. Deng, Weizhong Shao

Research Collection School Of Computing and Information Systems

The need for protecting rights over relational data is of ever increasing concern. There have recently been some pioneering works in this area. In this paper, we propose an effective fingerprinting scheme based on the idea of block method in the area of multimedia fingerprinting. The scheme ensures that certain bit positions of the data contain specific values. The bit positions are determined by the keys known only to the owner of the data and different buyers of the database have different bit positions and different specific values for those bit positions. The detection of the fingerprint can be completed …

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Cryptanalysis Of A Forward Secure Blind Signature Scheme With Provable Security, Shuhong Wang, Feng Bao, Robert H. Deng Dec 2005

Cryptanalysis Of A Forward Secure Blind Signature Scheme With Provable Security, Shuhong Wang, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

A forward secure blind signature scheme was proposed by Duc, Cheon and Kim, in ICICS 2003. The security of the scheme was proved to be equivalent to the strong RSA assumption in the random oracle model. In this paper we present an attack to the scheme by forging valid signatures with public keys only. The attack is so efficient that forging a valid signature needs less computation than legally generating a signature, even considering only the user side. Our result implies that the security proof of the scheme must be invalid. Furthermore we point out the fault of the proof …

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Authenticating Query Results In Data Publishing, Di Ma, Robert H. Deng, Hwee Hwa Pang, Jianying Zhou Dec 2005

Authenticating Query Results In Data Publishing, Di Ma, Robert H. Deng, Hwee Hwa Pang, Jianying Zhou

Research Collection School Of Computing and Information Systems

We propose a communication-efficient authentication scheme to authenticate query results disseminated by untrusted data publishing servers. In our scheme, signatures of multiple tuples in the result set are aggregated into one and thus the communication overhead incurred by the signature keeps constant. Next attr-MHTs (tuple based Merkle Hash Tree) are built to further reduce the communication overhead incurred by auxiliary authentication information (AAI). Besides the property of communication-efficiency, our scheme also supports dynamic SET operations (UNION, INTERSECTION) and dynamic JOIN with immunity to reordering attack.

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An Efficient And Robust Computational Framework For Studying Lifetime And Information Capacity In Sensor Networks, Enrique J. Duarte-Melo, Mingyan Liu, Archan Misra Dec 2005

An Efficient And Robust Computational Framework For Studying Lifetime And Information Capacity In Sensor Networks, Enrique J. Duarte-Melo, Mingyan Liu, Archan Misra

Research Collection School Of Computing and Information Systems

In this paper we investigate the expected lifetime and information capacity, defined as the maximum amount of data (bits) transferred before the first sensor node death due to energy depletion, of a data-gathering wireless sensor network. We develop a fluid-flow based computational framework that extends the existing approach, which requires precise knowledge of the layout/deployment of the network, i.e., exact sensor positions. Our method, on the other hand, views a specific network deployment as a particular instance (sample path) from an underlying distribution of sensor node layouts and sensor data rates. To compute the expected information capacity under this distribution-based …

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A Framework To Learn Bayesian Network From Changing, Multiple-Source Biomedical Data, Li G., Tze-Yun Leong Dec 2005

A Framework To Learn Bayesian Network From Changing, Multiple-Source Biomedical Data, Li G., Tze-Yun Leong

Research Collection School Of Computing and Information Systems

Structure learning in Bayesian network is a big issue. Many efforts have tried to solve this problem and quite a few algorithms have been proposed. However, when we attempt to apply the existing methods to microarray data, there are three main challenges: 1) there are many variables in the data set, 2) the sample size is small, and 3) microarray data are changing from experiment to experiment and new data are available quickly. To address these three problems, we assume that the major functions of a kind of cells do not change too much in different experiments, and propose a …

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Exploiting Self-Adaptive Posture-Based Focus Estimation For Lecture Video Editing, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong Nov 2005

Exploiting Self-Adaptive Posture-Based Focus Estimation For Lecture Video Editing, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

Head pose plays a special role in estimating a presenter’s focuses and actions for lecture video editing. This paper presents an efficient and robust head pose estimation algorithm to cope with the new challenges arising in the content management of lecture videos. These challenges include speed requirement, low video quality, variant presenting styles and complex settings in modern classrooms. Our algorithm is based on a robust hierarchical representation of skin color clustering and a set of pose templates that are automatically trained. Contextual information is also considered to refine pose estimation. Most importantly, we propose an online learning approach to …

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Motion-Based Approach For Bbc Rushes Structuring And Characterization, Chong-Wah Ngo, Zailiang Pan Nov 2005

Motion-Based Approach For Bbc Rushes Structuring And Characterization, Chong-Wah Ngo, Zailiang Pan

Research Collection School Of Computing and Information Systems

No abstract provided.

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Selective Object Stabilization For Home Video Consumers, Zailiang Pan, Chong-Wah Ngo Nov 2005

Selective Object Stabilization For Home Video Consumers, Zailiang Pan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper describes a unified approach for video stabilization. The essential goal is to stabilize image sequences that consist of moving foreground objects, which appear frequently in today's home videos captured by hand-held consumer cameras. Our proposed techniques mainly, rely on the analysis of;motion content. Three major components area initialization, segmentation and stabilization. In motion initialization, we propose a novel algorithm to efficiently search for the best possible frame in a sequence to start segmentation. Our segmentation algorithm is based on Expectation-Maximization (EM) framework which provides the mechanism for simultaneous estimation of motion models and their layers of support. Based …

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