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Articles 7051 - 7080 of 7446

Full-Text Articles in Physical Sciences and Mathematics

Tactics-Based Remote Execution For Mobile Computing, Rajesh Krishna Balan, Mahadev Satayanarayana, Soyoung Park, Tadashi Okoshi May 2003

Tactics-Based Remote Execution For Mobile Computing, Rajesh Krishna Balan, Mahadev Satayanarayana, Soyoung Park, Tadashi Okoshi

Research Collection School Of Computing and Information Systems

Remote execution can transform the puniest mobile device into a computing giant able to run resource-intensive applications such as natural language translation, speech recognition, face recognition, and augmented reality. However, easily partitioning these applications for remote execution while retaining application-specific information has proven to be a difficult challenge. In this paper, we show that automated dynamic repartitioning of mobile applications can be reconciled with the need to exploit application-specific knowledge. We show that the useful knowledge about an application relevant to remote execution can be captured in a compact declarative form calledtactics. Tactics capture the full range of meaningful partitions …

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On Machine Learning Methods For Chinese Document Classification, Ji He, Ah-Hwee Tan, Chew-Lim Tan May 2003

On Machine Learning Methods For Chinese Document Classification, Ji He, Ah-Hwee Tan, Chew-Lim Tan

Research Collection School Of Computing and Information Systems

This paper reports our comparative evaluation of three machine learning methods, namely k Nearest Neighbor (kNN), Support Vector Machines (SVM), and Adaptive Resonance Associative Map (ARAM) for Chinese document categorization. Based on two Chinese corpora, a series of controlled experiments evaluated their learning capabilities and efficiency in mining text classification knowledge. Benchmark experiments showed that their predictive performance were roughly comparable, especially on clean and well organized data sets. While kNN and ARAM yield better performances than SVM on small and clean data sets, SVM and ARAM significantly outperformed kNN on noisy data. Comparing efficiency, kNN was notably more costly …

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On The Strategy Of Supply Hubs For Cost Reduction And Responsiveness, Earl Barnes, Jim Dai, Shijie Deng, Doug Down, Mark Goh, Hoong Chuin Lau, Sharafali Moosa May 2003

On The Strategy Of Supply Hubs For Cost Reduction And Responsiveness, Earl Barnes, Jim Dai, Shijie Deng, Doug Down, Mark Goh, Hoong Chuin Lau, Sharafali Moosa

Research Collection School Of Computing and Information Systems

A supply hub is a location generally close to a manufacturer’s facility where all or some of its supplies are warehoused with the agreement that the materials will be paid for only when consumed. Supply hub is an innovative strategy employed by especially the electronics industry to achieve cost reduction and improved responsiveness. After first tracing the developments leading to the establishment of supply hubs, the paper then describes the dynamics of the operation of supply hubs. Case examples are provided to highlight the current practices. Finally, some research issues are identified.

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Ts-Pwlan: A Value-Add System For Providing Tiered Wireless Services In Public Hot-Spots, Arup Acharya, Chatschik Bisdikian, Archan Misra, Young-Bae Ko May 2003

Ts-Pwlan: A Value-Add System For Providing Tiered Wireless Services In Public Hot-Spots, Arup Acharya, Chatschik Bisdikian, Archan Misra, Young-Bae Ko

Research Collection School Of Computing and Information Systems

Access to data services via wireless LANs at private (e.g., corporations or home) and public "hot-spot" (e.g., hotels and airports) setting is becoming a common place daily. Data access via (for profit) public wireless LAN (PWLAN) installations is typically based on user subscription and preconfigured services profiles pertaining primarily access to the global Internet. The goal of the ts-PWLAN project is to define an architecture and a prototype implementation that enables the provision of premium and non-premium tiers of services to transient and non-transient users. ts-PWLAN provides for dynamic renegotiations of tier of services and enables various billing modes, e.g., …

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Efficient Native Xml Storage System (Enaxs), Khin-Myo Win, Wee-Keong Ng, Ee Peng Lim Apr 2003

Efficient Native Xml Storage System (Enaxs), Khin-Myo Win, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

XML is a self-describing meta-language and fast emerging as a dominant standard for Web data exchange among various applications. With the tremendous growth of XML documents, an efficient storage system is required to manage them. The conventional databases, which require all data to adhere to an explicitly specified rigid schema, are unable to provide an efficient storage for tree-structured XML documents. A new data model that is specifically designed for XML documents is required. In this paper, we propose a new storage system, named Efficient Native XML Storage System (ENAXS), for large and complex XML documents. ENAXS stores all XML …

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Stegfs: A Steganographic File System, Hwee Hwa Pang, Kian-Lee Tan, Xuan Zhou Mar 2003

Stegfs: A Steganographic File System, Hwee Hwa Pang, Kian-Lee Tan, Xuan Zhou

Research Collection School Of Computing and Information Systems

While user access control and encryption can protect valuable data from passive observers, those techniques leave visible ciphertexts that are likely to alert an active adversary to the existence of the data, who can then compel an authorized user to disclose it. This paper introduces StegFS, a steganographic file system that aims to overcome that weakness by offering plausible deniability to owners of protected files. StegFS securely hides user-selected files in a file system so that, without the corresponding access keys, an attacker would not be able to deduce their existence, even if the attacker is thoroughly familiar with the …

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Energy-Efficient Broadcast And Multicast Trees For Reliable Wireless Communication, Suman Banerjee, Archan Misra, Jihwang Yeo, Ashok Agrawala Mar 2003

Energy-Efficient Broadcast And Multicast Trees For Reliable Wireless Communication, Suman Banerjee, Archan Misra, Jihwang Yeo, Ashok Agrawala

Research Collection School Of Computing and Information Systems

We define energy-efficient broadband and multicast schemes for reliable communication in multi-hop wireless networks. Unlike previous techniques, the choice of neighbors in the broadband and multicast trees in these schemes, are based not only on the link distance, but also on the error rates associated with the link. Our schemes can be implemented using both positive and negative acknowledgement based reliable broadcast techniques in the link layer. Through simulations, we show that our scheme achieves up to 45% improvement over previous schemes on realistic 100-node network topologies. A positive acknowledgment based implementation is preferred. Our simulations show that the additional …

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Maca-P: A Mac For Concurrent Transmissions In Multi-Hop Wireless Networks, Arup Acharya, Archan Misra, Sorav Bansal Mar 2003

Maca-P: A Mac For Concurrent Transmissions In Multi-Hop Wireless Networks, Arup Acharya, Archan Misra, Sorav Bansal

Research Collection School Of Computing and Information Systems

This paper presents the initial design and performance study of MACA-P, a RTS/CTS based MAC protocol that enables simultaneous transmissions in multihop ad-hoc wireless networks. Providing such low-cost multihop and high performance wireless access networks is an important enabler of pervasive computing. MACA-P is a set of enhancements to the 802.11 DCF that allows parallel transmissions in many situations when two neighboring nodes are either both receivers or both transmitters, but a receiver and a transmitter are not neighbors. Like 802.11, MACA-P contains a contention-based reservation phase prior to data transmission. However, the data transmission is delayed by a control …

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Adaptive Transmission Power For Optimal Energy Reliable Multi-Hop Wireless Communication, Suman Banerjee, Archan Misra Mar 2003

Adaptive Transmission Power For Optimal Energy Reliable Multi-Hop Wireless Communication, Suman Banerjee, Archan Misra

Research Collection School Of Computing and Information Systems

We define a transmission power adaptation-based routing technique that finds optimal paths for minimum energy reliable data transfer in multi-hop wireless networks. This optimal choice of the transmission power depends on the link distance between the two nodes and the channel characteristics. Typical energy efficient routing techniques use a transmission power such that the received signal power at the destination minimally exceeds a desired threshold signal strength level. In this paper we argue that such a choice of the transmission power does not always lead to optimal energy routes, since it does not consider differences in the receiver noise levels. …

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Hierarchical Text Classification Methods And Their Specification, Ee Peng Lim, Aixin Sun, Wee-Keong Ng Mar 2003

Hierarchical Text Classification Methods And Their Specification, Ee Peng Lim, Aixin Sun, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

Hierarchical text classification refers to assigning text documents to the categories in a given category tree based on their content. With large number of categories organized as a tree, hierarchical text classification helps users to find information more quickly and accurately. Nevertheless, hierarchical text classification methods in the past have often been constructed in a proprietary manner. The construction steps often involve human efforts and are not completely automated. In this chapter, we therefore propose a specification language known as HCL (Hierarchical Classification Language). HCL is designed to describe a hierarchical classification method including the definition of a category tree …

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Motion Analysis And Segmentation Through Spatio-Temporal Slices Processing, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang Mar 2003

Motion Analysis And Segmentation Through Spatio-Temporal Slices Processing, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

This paper presents new approaches in characterizing and segmenting the content of video. These approaches are developed based upon the pattern analysis of spatio-temporal slices. While traditional approaches to motion sequence analysis tend to formulate computational methodologies on two or three adjacent frames, spatio-temporal slices provide rich visual patterns along a larger temporal scale. In this paper, we first describe a motion computation method based on a structure tensor formulation. This method encodes visual patterns of spatio-temporal slices in a tensor histogram, on one hand, characterizing the temporal changes of motion over time, on the other hand, describing the motion …

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Comparing The Routing Energy Overheads Of Ad-Hoc Routing Protocols, Sorav Bansal, Rajeev Shorey, Archan Misra Mar 2003

Comparing The Routing Energy Overheads Of Ad-Hoc Routing Protocols, Sorav Bansal, Rajeev Shorey, Archan Misra

Research Collection School Of Computing and Information Systems

We use simulations to study the comparative routing overheads of three ad-hoc routing protocols, namely AODV, DSDV and DSR. In contrast to earlier studies, we focus exclusively on the energy consumption and not on other metrics such as the number of routing packets. In particular, we study the `range effects' of the three protocols, i.e., how changes to the transmission power and transmission radius affect the overall energy consumed by routing-related packets. Due to the broadcast nature of the wireless medium, the energy spent in packet receptions is almost as important as the transmission power; using the number of transmissions …

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Meeting The Software Engineering Challenges Of Adaptive Mobile Applications, Rajesh Krishna Balan, Joao Pedro Sousa, Mahadev Satyanarayanan Feb 2003

Meeting The Software Engineering Challenges Of Adaptive Mobile Applications, Rajesh Krishna Balan, Joao Pedro Sousa, Mahadev Satyanarayanan

Research Collection School Of Computing and Information Systems

A critical factor for the commercial success of mobile and task-specific devices is the fast turnaround time of software development. However, developing software for mobile devices is especially hard since applications need to be aware of and adapt to changing resources such as bandwidth and battery.

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On Quantitative Evaluation Of Clustering Systems, Ji He, Ah-Hwee Tan, Chew-Lim Tan, Sam-Yuan Sung Jan 2003

On Quantitative Evaluation Of Clustering Systems, Ji He, Ah-Hwee Tan, Chew-Lim Tan, Sam-Yuan Sung

Research Collection School Of Computing and Information Systems

Clustering refers to the task of partitioning unlabelled data into meaningful groups (clusters). It is a useful approach in data mining processes for identifying hidden patterns and revealing underlying knowledge from large data collections. The application areas of clustering, to name a few, include image segmentation, information retrieval, document classification, associate rule mining, web usage tracking, and transaction analysis.

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Instance Based Attribute Identification In Database Integration, Ee Peng Lim, Cecil Chua, Roger Hsiang-Li Chiang Jan 2003

Instance Based Attribute Identification In Database Integration, Ee Peng Lim, Cecil Chua, Roger Hsiang-Li Chiang

Research Collection School Of Computing and Information Systems

Most research on attribute identification in database integration has focused on integrating attributes using schema and summary information derived from the attribute values. No research has attempted to fully explore the use of attribute values to perform attribute identification. We propose an attribute identification method that employs schema and summary instance information as well as properties of attributes derived from their instances. Unlike other attribute identification methods that match only single attributes, our method matches attribute groups for integration. Because our attribute identification method fully explores data instances, it can identify corresponding attributes to be integrated even when schema information …

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Performance Measurement Framework For Hierarchical Text Classification, Ee Peng Lim, Aixin Sun, Wee-Keong Ng Jan 2003

Performance Measurement Framework For Hierarchical Text Classification, Ee Peng Lim, Aixin Sun, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

Hierarchical text classification or simply hierarchical classification refers to assigning a document to one or more suitable categories from a hierarchical category space. In our literature survey, we have found that the existing hierarchical classification experiments used a variety of measures to evaluate performance. These performance measures often assume independence between categories and do not consider documents misclassified into categories that are similar or not far from the correct categories in the category tree. In this paper, we therefore propose new performance measures for hierarchical classification. The proposed performance measures consist of category similarity measures and distance-based measures that consider …

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Advances In Mobile Commerce Technologies, Ee Peng Lim, Keng Siau Jan 2003

Advances In Mobile Commerce Technologies, Ee Peng Lim, Keng Siau

Research Collection School Of Computing and Information Systems

No abstract provided.

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Trading Agents Competing: Performance, Progress And Market Effectiveness, Michael P. Wellman, Shih-Fen Cheng, Daniel M. Reeves, Kevin M. Lochner Jan 2003

Trading Agents Competing: Performance, Progress And Market Effectiveness, Michael P. Wellman, Shih-Fen Cheng, Daniel M. Reeves, Kevin M. Lochner

Research Collection School Of Computing and Information Systems

The annual trading agent competition offers agent designers a forum for evaluating programmed trading techniques in a challenging market scenario. TAC aims to spur research by enabling researchers to compare techniques on a common problem and build on each other's ideas. A fixed set of assumptions and environment settings facilitates communication of methods and results. As a multiyear event, TAC lets researchers observe trading agents' progress over time, in effect accelerating the evolution of an adapted population of traders. Given all the participant effort invested, it is incumbent on us to learn as much from the experience as possible. After …

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Semantic Exploration Of Lecture Videos, Edward Altman, Yu Chen, Wai Chong Low Dec 2002

Semantic Exploration Of Lecture Videos, Edward Altman, Yu Chen, Wai Chong Low

Research Collection School Of Computing and Information Systems

E-Learning is rapidly changing the way that universities and corporations offer education and training. In recent years, the acquisition and distribution of rich media content has been largely automated, However, existing applications are functionally and visually static and remain organized around the delivery media, rather than the knowledge representation and learning tasks of the student. The innovative approach of this system is the extraction of semantically meaningful structures in the lecture combined with text analysis to support task based queries. In this demonstration we will show this combination of pedagogical and content descriptions leads to novel forms of visualization and …

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Resource Annotation Framework In A Georeferenced And Geospatial Digital Library, Zehua Liu, Ee Peng Lim, Dion Hoe-Lian Goh Dec 2002

Resource Annotation Framework In A Georeferenced And Geospatial Digital Library, Zehua Liu, Ee Peng Lim, Dion Hoe-Lian Goh

Research Collection School Of Computing and Information Systems

G-Portal is a georeferenced and geospatial digital library that aims to identify, classify and organize geospatial and georeferenced resources on the web and to provide digital library services for these resources. Annotation service is supported in G-Portal to enable users to contribute content to the digital library. In this paper, we present a resource annotation framework for georeferenced and geospatial digital libraries and discuss its application in G-Portal. The framework is fiexible for managing annotations of heterogeneous web resources. It allows users to contribute not only the annotation content but also the schema of the annotations. Meanwhile, other digital library …

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A Data Mining Approach To Library New Book Recommendations, San-Yih Hwang, Ee Peng Lim Dec 2002

A Data Mining Approach To Library New Book Recommendations, San-Yih Hwang, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In this paper, we propose a data mining approach to recommending new library books that have never been rated or borrowed by users. In our problem context, users are characterized by their demographic attributes, and concept hierarchies can be defined for some of these demographic attributes. Books are assigned to the base categories of a taxonomy. Our goal is therefore to identify the type of users interested in some specific type of books. We call such knowledge generalized profile association rules. In this paper, we propose a new definition of rule interestingness to prune away rules that are redundant and …

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On Clustering And Retrieval Of Video Shots Through Temporal Slices Analysis, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang Dec 2002

On Clustering And Retrieval Of Video Shots Through Temporal Slices Analysis, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

Based on the analysis of temporal slices, we propose novel approaches for clustering and retrieval of video shots. Temporal slices are a set of two-dimensional (2-D) images extracted along the time dimension of an image volume. They encode rich set of visual patterns for similarity measure. In this paper, we first demonstrate that tensor histogram features extracted from temporal slices are suitable for motion retrieval. Subsequently, we integrate both tensor and color histograms for constructing a two-level hierarchical clustering structure. Each cluster in the top level contains shots with similar color while each cluster in bottom level consists of shots …

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Crystalclear: Active Visualization Of Association Rules, Hian-Huat Ong, Kok-Leong Ong, Wee-Keong Ng, Ee Peng Lim Dec 2002

Crystalclear: Active Visualization Of Association Rules, Hian-Huat Ong, Kok-Leong Ong, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Effective visualization is an important aspect of active data mining. In the context of association rules, this need has been driven by the large amount of rules produced from a run of the algorithm. To be able to address real user needs, the rules need to be summarized and organized so that it can be interpreted and applied in a timely manner. In this paper, we propose two visualization techniques that is an improvement over those used by existing data mining packages. In particular, we address the visualization of "differences" in the set of rules due to incremental changes in …

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Intergenerational Partnerships In The Design Of A Digital Library Of Geography Examination Resources, Yin-Leng Theng, Dion Hoe-Lian Goh, Ee Peng Lim, Zehua Liu, Natalie Lee-San Pang, Patricia Bao-Bao Wong, Lian-Heong Chua Dec 2002

Intergenerational Partnerships In The Design Of A Digital Library Of Geography Examination Resources, Yin-Leng Theng, Dion Hoe-Lian Goh, Ee Peng Lim, Zehua Liu, Natalie Lee-San Pang, Patricia Bao-Bao Wong, Lian-Heong Chua

Research Collection School Of Computing and Information Systems

This paper describes the engagement of intergenerational partners in the design of a digital library of geographical resources (GeogDL) to help prepare Singapore students for a national examination in geography. GeogDL is built on top of G-Portal, a digital library providing services over geospatial and georeferenced Web content. Scenario-based design and claims analysis were employed as a means of refinement to the initial design of the GeogDL prototype.

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Vdl: A Language For Active Mining Variants Of Association Rules, Kok-Leong Ong, Wee-Keong Ng, Ee Peng Lim Dec 2002

Vdl: A Language For Active Mining Variants Of Association Rules, Kok-Leong Ong, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

The popularity of association rules has resulted in several variations being proposed. In each case, additional attributes in the data are considered so as to produce more informative rules. In the context of active mining, different types of rules may be required over a period of time due to knowledge needs or the availability of new attributes. The present approach is the ad-hoc development of algorithms for each variant of rules. This is time consuming and costly, and is a stumping block to the vision of active mining. We argue that knowledge needs and the changing characteristics of the data …

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Motion Retrieval By Temporal Slices Analysis, Chong-Wah Ngo, Chong-Wah Ngo, Hong-Jiang Zhang Dec 2002

Motion Retrieval By Temporal Slices Analysis, Chong-Wah Ngo, Chong-Wah Ngo, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

In this papel; we investigate video shots retrieval based on the analysis of temporal slice images. Temporal slices are a set of2D images extracted along the time dimension of image sequences. They encode rich set of motion clues for shot similarity measure. Because motion is depicted as texture orientation in temporal slices, we utilize various texture features such as tensor histogram, Gabor feature, and the statistical feature of co-occurrence matrix extracted directly from slices for motion description and retrieval. In this way, motion retrieval can be treated in a similar way as texture retrieval problem. Experimental results indicate that the …

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The Capacity Of Multi-Hop Wireless Networks With Tcp Regulated Traffic, Sorav Bansal, Rajeev Shorey, Shobhit Chugh, Anurag Goel, Kapil Kumar, Archan Misra Nov 2002

The Capacity Of Multi-Hop Wireless Networks With Tcp Regulated Traffic, Sorav Bansal, Rajeev Shorey, Shobhit Chugh, Anurag Goel, Kapil Kumar, Archan Misra

Research Collection School Of Computing and Information Systems

We study the dependence of the capacity of multi-hop wireless networks on the transmission range of nodes in the network with TCP regulated traffic. Specifically, we examine the sensitivity of the capacity to the speed of the nodes and the number of TCP connections in an ad hoc network. By incorporating the notion of a minimal acceptable QoS metric (loss) for an individual session, we argue that the QoS-aware capacity is a more accurate model of the TCP-centric capacity of an ad-hoc network. We study the dependence of capacity on the source application (Telnet or FTP) and on the choice …

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Discrete Singular Convolution And Its Application To The Analysis Of Plates With Internal Supports. Part 1: Theory And Algorithm, G. W. Wei, Yibao Zhao, Y. Xiang Nov 2002

Discrete Singular Convolution And Its Application To The Analysis Of Plates With Internal Supports. Part 1: Theory And Algorithm, G. W. Wei, Yibao Zhao, Y. Xiang

Research Collection Lee Kong Chian School Of Business

This paper presents a novel computational approach, the discrete singular convolution (DSC) algorithm, for analysing plate structures. The basic philosophy behind the DSC algorithm for the approximation of functions and their derivatives is studied. Approximations to the delta distribution are constructed as either bandlimited reproducing kernels or approximate reproducing kernels. Unified features of the DSC algorithm for solving differential equations are explored. It is demonstrated that different methods of implementation for the present algorithm, such as global, local, Galerkin, collocation, and finite difference, can be deduced from a single starting point. The use of the algorithm for the vibration analysis …

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Mining Of Correlated Rules In Genome Sequences, L. Lin, L. Wong, Tze-Yun Leong, P. S. Lai Nov 2002

Mining Of Correlated Rules In Genome Sequences, L. Lin, L. Wong, Tze-Yun Leong, P. S. Lai

Research Collection School Of Computing and Information Systems

With the huge amount of data collected by scientists in the molecular genetics community in recent years, there exists a need to develop some novel algorithms based on existing data mining techniques to discover useful information from genome databases. We propose an algorithm that integrates the statistical method, association rule mining, and classification rule mining in the discovery of allelic combinations of genes that are peculiar to certain phenotypes of diseased patients.

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Motion-Based Video Representation For Scene Change Detection, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang Nov 2002

Motion-Based Video Representation For Scene Change Detection, Chong-Wah Ngo, Ting-Chuen Pong, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

In this paper, we present a new framework to automatically group similar shots into one scene, where a scene is generally referred to as a group of shots taken place in the same site. Two major components in this framework are based on the motion characterization and background segmentation. The former component leads to an effective video representation scheme by adaptively selecting and forming keyframes. The later is considered novel in that background reconstruction is incorporated into the detection of scene change. These two components, combined with the color histogram intersection, establish our basic concept on assessing the similarity of …

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