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Physical Sciences and Mathematics Commons™

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2005

Singapore Management University

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Full-Text Articles in Physical Sciences and Mathematics

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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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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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 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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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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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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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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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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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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A Threshold-Based Algorithm For Continuous Monitoring Of K Nearest Neighbors, Kyriakos Mouratidis, Dimitris Papadias, Spiridon Bakiras, Yufei Tao Nov 2005

A Threshold-Based Algorithm For Continuous Monitoring Of K Nearest Neighbors, Kyriakos Mouratidis, Dimitris Papadias, Spiridon Bakiras, Yufei Tao

Research Collection School Of Computing and Information Systems

Assume a set of moving objects and a central server that monitors their positions over time, while processing continuous nearest neighbor queries from geographically distributed clients. In order to always report up-to-date results, the server could constantly obtain the most recent position of all objects. However, this naïve solution requires the transmission of a large number of rapid data streams corresponding to location updates. Intuitively, current information is necessary only for objects that may influence some query result (i.e., they may be included in the nearest neighbor set of some client). Motivated by this observation, we present a threshold-based algorithm …

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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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Mining Ontological Knowledge From Domain-Specific Text Documents, Xing Jiang, Ah-Hwee Tan Nov 2005

Mining Ontological Knowledge From Domain-Specific Text Documents, Xing Jiang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Traditional text mining systems employ shallow parsing techniques and focus on concept extraction and taxonomic relation extraction. This paper presents a novel system called CRCTOL for mining rich semantic knowledge in the form of ontology from domain-specific text documents. By using a full text parsing technique and incorporating both statistical and lexico-syntactic methods, the knowledge extracted by our system is more concise and contains a richer semantics compared with alternative systems. We conduct a case study wherein CRCTOL extracts ontological knowledge, specifically key concepts and semantic relations, from a terrorism domain text collection. Quantitative evaluation, by comparing with a state-of-the-art …

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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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Query Processing In Spatial Databases Containing Obstacles, Jun Zhang, Dimitris Papadias, Kyriakos Mouratidis, Manli Zhu Nov 2005

Query Processing In Spatial Databases Containing Obstacles, Jun Zhang, Dimitris Papadias, Kyriakos Mouratidis, Manli Zhu

Research Collection School Of Computing and Information Systems

Despite the existence of obstacles in many database applications, traditional spatial query processing assumes that points in space are directly reachable and utilizes the Euclidean distance metric. In this paper, we study spatial queries in the presence of obstacles, where the obstructed distance between two points is defined as the length of the shortest path that connects them without crossing any obstacles. We propose efficient algorithms for the most important query types, namely, range search, nearest neighbours, e-distance joins, closest pairs and distance semi-joins, assuming that both data objects and obstacles are indexed by R-trees. The effectiveness of the proposed …

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On Security Notions Of Steganographic Systems, Kisik Chang, Robert H. Deng, Feng Bao, Sangjin Lee, Hyungjun Kim Nov 2005

On Security Notions Of Steganographic Systems, Kisik Chang, Robert H. Deng, Feng Bao, Sangjin Lee, Hyungjun Kim

Research Collection School Of Computing and Information Systems

We define the notion of pseudoprocessingness to formulate chosen-input-attack, chosen-stego-attack, and key-recovery. We then construct a efficient, provable secure steganographic algorithm against chosen-input-attack and key-recovery. So far as we know, this is the first paper dealing with those security notions.

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Anonymous Dos-Resistant Access Control Protocol Using Passwords For Wireless Networks, Zhiguo Wan, Robert H. Deng, Feng Bao, Akkihebbal L. Ananda Nov 2005

Anonymous Dos-Resistant Access Control Protocol Using Passwords For Wireless Networks, Zhiguo Wan, Robert H. Deng, Feng Bao, Akkihebbal L. Ananda

Research Collection School Of Computing and Information Systems

Wireless networks have gained overwhelming popularity over their wired counterpart due to their great flexibility and convenience, but access control of wireless networks has been a serious problem because of the open medium. Passwords remain the most popular way for access control as well as authentication and key exchange. But existing password-based access control protocols are not satisfactory in that they do not provide DoS-resistance or anonymity. In this paper we analyze the weaknesses of an access control protocol using passwords for wireless networks in IEEE LCN 2001, and propose a different access control protocol using passwords for wireless networks. …

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Accurately Extracting Coherent Relevant Passages Using Hidden Markov Models, Jing Jiang, Chengxiang Zhai Nov 2005

Accurately Extracting Coherent Relevant Passages Using Hidden Markov Models, Jing Jiang, Chengxiang Zhai

Research Collection School Of Computing and Information Systems

In this paper, we present a principled method for accurately extracting coherent relevant passages of variable lengths using HMMs. We show that with appropriate parameter estimation, the HMM method outperforms a number of strong baseline methods on two data sets.

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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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Informal Animation Sketching With K-Sketch, Richard Christopher Davis Oct 2005

Informal Animation Sketching With K-Sketch, Richard Christopher Davis

Research Collection School of Computing and Information Systems

Animation is a powerful medium that is accessible to few, because current animation tools are extremely complex. This complexity arises partially from current tools’ focus on precise, often unnecessary details and partially from the difficulty of finding a small but sufficiently powerful set of tool features. We are designing K-Sketch, an informal 2D animation tool that uses sketching and demonstration to radically reduce the time needed to create an animation. Our field studies investigating the needs of current anima-tion tool users and would-be users are helping us to mini-mize complexity by showing us how to prioritize the many possible tool …

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Managerial Assessments Of E-Business Investment Opportunities: A Field Study, Anandhi S. Bharadwaj, Amrit Tiwana Oct 2005

Managerial Assessments Of E-Business Investment Opportunities: A Field Study, Anandhi S. Bharadwaj, Amrit Tiwana

Research Collection School Of Computing and Information Systems

Managers charged with assessing investment opportunities for information technologies such as e-business projects face considerable uncertainty in their decision-making processes. Contemporary theories of the firm and the normative prescriptions thereof emphasize the potential for such investments to augment firm-level knowledge and relational capabilities. However, prior research has not examined the relative emphases that managers place on the knowledge and relational capability-augmenting characteristics of the e-business investments. In this paper, we develop a model to assess whether managerial evaluations of e-business investment opportunities are consistent with these normative and theoretical prescriptions. A test of the model using survey data on 485 …

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And/Or Graph And Search Algorithm For Discovering Composite Web Services, Qianhui (Althea) Liang, Stanley Y. W. Su Oct 2005

And/Or Graph And Search Algorithm For Discovering Composite Web Services, Qianhui (Althea) Liang, Stanley Y. W. Su

Research Collection School Of Computing and Information Systems

This paper presents a formalization of the Web Service composition problem as a search problem in an AND/OR graph, and a search algorithm for searching the graph to identify composite service(s) that satisfies a Web Service request. Given a service request that can only be satisfied by a composition of Web Services, we identify the service categories that are relevant to the request and dynamically construct an AND/OR graph to capture the input/output dependencies among the Web Services of these service categories. The graph is modified, based on the information provided in the service request. The search algorithm is then …

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Common Pattern Discovery Using Earth Mover's Distance And Local Flow Maximization, Hung-Khoon Tan, Chong-Wah Ngo Oct 2005

Common Pattern Discovery Using Earth Mover's Distance And Local Flow Maximization, Hung-Khoon Tan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

In this paper, we present a novel segmentation-insensitive approach for mining common patterns from 2 images. We develop an algorithm using the earth movers distance (EMD) framework, unary and adaptive neighborhood color similarity. We then propose a novel local flow maximization approach to provide the best estimation of location and scale of the common pattern. This is achieved by performing an iterative optimization in search of the most stable flows' centroid. Common pattern discovery is difficult owing to the huge search space and problem domain. We intend to solve this problem by reducing the search space through identifying the location …

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Towards Semantic Service Request Of Web Service Composition, Qianhui Althea Liang, Jen-Yao Chung, Steven M. Miller Oct 2005

Towards Semantic Service Request Of Web Service Composition, Qianhui Althea Liang, Jen-Yao Chung, Steven M. Miller

Research Collection School Of Computing and Information Systems

When meeting the challenges in automatic and semi-automatic Web service composition, capturing the user's service demand and preferences is as important as knowing what the services can do. This paper discusses the idea of semantic service requests for composite services, and presents a way to model the elements of a composite service request as user preferences and constraints. The model is based on an interactive and iterative strategy meant to obtain the exact requirements from potential service consumers. The markup vocabularies and associated inference mechanism of OWL-S are used as a means to bring semantics to service requests. Language constructs …

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Dsim: A Distance-Based Indexing Method For Genomic Sequences, Xia Cao, Beng-Chin Ooi, Hwee Hwa Pang, Kian-Lee Tan, Anthony K. H. Tung Oct 2005

Dsim: A Distance-Based Indexing Method For Genomic Sequences, Xia Cao, Beng-Chin Ooi, Hwee Hwa Pang, Kian-Lee Tan, Anthony K. H. Tung

Research Collection School Of Computing and Information Systems

In this paper, we propose a Distance-based Sequence Indexing Method (DSIM) for indexing and searching genome databases. Borrowing the idea of video compression, we compress the genomic sequence database around a set of automatically selected reference words, formed from high-frequency data substrings and substrings in past queries. The compression captures the distance of each non-reference word in the database to some reference word. At runtime, a query is processed by comparing its substrings with the compressed data strings, through their distances to the reference words. We also propose an efficient scheme to incrementally update the reference words and the compressed …

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Automatic 3d Face Modeling Using 2d Active Appearance Models, Jianke Zhu, Steven Hoi, Michael R. Lyu Oct 2005

Automatic 3d Face Modeling Using 2d Active Appearance Models, Jianke Zhu, Steven Hoi, Michael R. Lyu

Research Collection School Of Computing and Information Systems

Although a lot of promising research findings have been studied on 3D face modeling in the past years, it is still a challenge to generate realistic 3D human face models and facial animations. This paper presents a novel approach to model 3D faces automatically from still images or video sequences without manual interactions. Our proposed scheme comprises three steps. First, we offline construct 3D shape models using Active Appearance Models (AAMs), which saves large computation costs for online modeling. Second, based on the computed 3D shape models, we propose an efficient algorithm to estimate the parameters of 3D pose and …

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