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Articles 6811 - 6840 of 7446

Full-Text Articles in Physical Sciences and Mathematics

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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Nil Is Not Nothing: Recognition Of Chinese Network Informal Language Expressions, Yunqing Xia, Kam-Fai Wong, Wei Gao Oct 2005

Nil Is Not Nothing: Recognition Of Chinese Network Informal Language Expressions, Yunqing Xia, Kam-Fai Wong, Wei Gao

Research Collection School Of Computing and Information Systems

Informal language is actively used in network-mediated communication, e.g. chat room, BBS, email and text message. We refer the anomalous terms used in such context as network informal language (NIL) expressions. For example, “஧(ou3)” is used to replace “ᚒ(wo3)” in Chinese ICQ. Without unconventional resource, knowledge and techniques, the existing natural language processing approaches exhibit less effectiveness in dealing with NIL text. We propose to study NIL expressions with a NIL corpus and investigate techniques in processing NIL expressions. Two methods for Chinese NIL expression recognition are designed in NILER system. The experimental results show that pattern matching method produces …

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Nil Is Not Nothing: Recognition Of Chinese Network Informal Language Expressions, Yunqing Xia, Wong, Wei Gao, Wei Gao Oct 2005

Nil Is Not Nothing: Recognition Of Chinese Network Informal Language Expressions, Yunqing Xia, Wong, Wei Gao, Wei Gao

Research Collection School Of Computing and Information Systems

Informal language is actively used in network-mediated communication, e.g. chat room, BBS, email and text message. We refer the anomalous terms used in such context as network informal language (NIL) expressions. For example, “偶(ou3)” is used to replace “我(wo3)” in Chinese ICQ. Without unconventional resource, knowledge and techniques, the existing natural language processing approaches exhibit less effectiveness in dealing with NIL text. We propose to study NIL expressions with a NIL corpus and investigate techniques in processing NIL expressions. Two methods for Chinese NIL expression recognition are designed in NILER system. The experimental results show that pattern matching method produces …

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

Informal Animation Sketching With K-Sketch, Richard C. 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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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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Forms Of Expression For Designing Visual Languages For Animation, Richard Christopher Davis, James A. Landay Sep 2005

Forms Of Expression For Designing Visual Languages For Animation, Richard Christopher Davis, James A. Landay

Research Collection School of Computing and Information Systems

We present further steps in our research into visual languages for animation. Animation is a rich mode of communication that is currently accessible to few, because animation systems are complex. Some systems try to make animation simple but put severe limits on users’ creative expression. Our field studies are demonstrating that would-be animators need to express animation in a wide variety of ways. We are developing a taxonomy of forms of expression for animation that will help the designers of visual languages for animation to determine which expressive forms to support. Our end goal is to build animation sketching systems …

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New Efficient Mds Array Codes For Raid Part I: Reed-Solomon-Like Codes For Tolerating Three Disk Failures, Gui-Liang Feng, Robert H. Deng, Feng Bao, Jia-Chen Shen Sep 2005

New Efficient Mds Array Codes For Raid Part I: Reed-Solomon-Like Codes For Tolerating Three Disk Failures, Gui-Liang Feng, Robert H. Deng, Feng Bao, Jia-Chen Shen

Research Collection School Of Computing and Information Systems

This paper presents a class of binary maximum distance separable (MDS) array codes for tolerating disk failures in redundant arrays of inexpensive disks (RAID) architecture based on circular permutation matrices. The size of the information part is m×n, the size of the parity-check part is m×3, and the minimum distance is 4, where n is the number of information disks, the number of parity-check disks is 3, and (m+1) is a prime integer. In practical applications, m can be very large and n is from 20 to 50. The code rate is R=n/(n+3). These codes can be used for tolerating …

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Solving Generalized Open Constraint Optimization Problem Using Two-Level Multi-Agent Framework, Hoong Chuin Lau, Lei Zhang, Chang Liu Sep 2005

Solving Generalized Open Constraint Optimization Problem Using Two-Level Multi-Agent Framework, Hoong Chuin Lau, Lei Zhang, Chang Liu

Research Collection School Of Computing and Information Systems

The Open Constraint Optimization Problem (OCOP) refers to the COP where constraints and variable domains can change over time and agents' opinions have to be sought over a distributed network to form a solution. The openness of the problem has caused conventional approaches to COP such as branch-and-bound to fail to find optimal solutions. OCOP is a new problem and the approach to find an optimal solution (minimum total cost) introduced in [1] is based on an unrealistic assumption that agents are willing to report their options in nondecreasing order of cost. In this paper, we study a generalized OCOP …

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Security Analysis And Improvement Of Return Routability Protocol, Ying Qiu, Jianying Zhou, Robert H. Deng Sep 2005

Security Analysis And Improvement Of Return Routability Protocol, Ying Qiu, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

Mobile communication plays a more and more important role in computer networks. How to authenticate a new connecting address belonging to a said mobile node is one of the key issues in mobile networks. This paper analyzes the Return Routability (RR) protocol and proposes an improved security solution for the RR protocol without changing its architecture. With the improvement, three types of redirect attacks can be prevented.

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Partial Adjustable Autonomy In Multi-Agent Environment And Its Application To Military Logistics, Hoong Chuin Lau, Lucas Agussurja, Ramesh Thangarajoo Sep 2005

Partial Adjustable Autonomy In Multi-Agent Environment And Its Application To Military Logistics, Hoong Chuin Lau, Lucas Agussurja, Ramesh Thangarajoo

Research Collection School Of Computing and Information Systems

In a rapidly changing environment, the behavior and decision-making power of agents may have to be adaptive with respect to a fluctuating autonomy. In this paper, a centralized fuzzy approach is proposed to sense changes in environmental conditions and translate them to changes in agent autonomy. A distributed coalition formation scheme is then applied to allow agents in the new autonomy to renegotiate to establish schedule consistency. The proposed framework is applied to a real-time logistics control of a military hazardous material storage facility under peace-to-war transition.

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Low Latency Multimedia Broadcast In Multi-Rate Wireless Meshes, Chun-Tong Chou, Archan Misra Sep 2005

Low Latency Multimedia Broadcast In Multi-Rate Wireless Meshes, Chun-Tong Chou, Archan Misra

Research Collection School Of Computing and Information Systems

In a multi-rate wireless network, a node can dynamically adjust its link transmission rate by switching between different modulation schemes. For the current IEEE802.11a/b/g standards, this rate adjustment is limited to unicast traffic only while multicast and broadcast traffic is always transmitted at the lowest possible rate. In this paper, we consider a novel type of multi-rate mesh networks where a node can dynamically adjust its link layer multicast rates to its neighbours. In particular, we consider the problem of realising low latency network-wide broadcast in this type of multi-rate wireless meshes. We will first show that the multi-rate broadcast …

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Forms Of Expression For Designing Visual Languages For Animation, Richard C. Davis, James A. Landay Sep 2005

Forms Of Expression For Designing Visual Languages For Animation, Richard C. Davis, James A. Landay

Research Collection School Of Computing and Information Systems

We present further steps in our research into visual languages for animation. Animation is a rich mode of communication that is currently accessible to few, because animation systems are complex. Some systems try to make animation simple but put severe limits on users’ creative expression. Our field studies are demonstrating that would-be animators need to express animation in a wide variety of ways. We are developing a taxonomy of forms of expression for animation that will help the designers of visual languages for animation to determine which expressive forms to support. Our end goal is to build animation sketching systems …

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Cuhk At Imageclef 2005: Cross-Language And Cross-Media Image Retrieval, Steven C. H. Hoi, J. Zhu, M. Lyu Sep 2005

Cuhk At Imageclef 2005: Cross-Language And Cross-Media Image Retrieval, Steven C. H. Hoi, J. Zhu, M. Lyu

Research Collection School Of Computing and Information Systems

In this paper, we describe our studies of cross-language and cross-media image retrieval at the ImageCLEF 2005. This is the first participation of our CUHK (The Chinese University of Hong Kong) group at ImageCLEF. The task in which we participated is the “bilingual ad hoc retrieval” task. There are three major focuses and contributions in our participation. The first is the empirical evaluation of language models and smoothing strategies for cross-language image retrieval. The second is the evaluation of cross-media image retrieval, i.e., combining text and visual contents for image retrieval. The last is the evaluation of bilingual image retrieval …

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Managing Geography Learning Objects Using Personalized Project Spaces In G-Portal, Dion Hoe-Lian Goh, Aixin Sun, Wenbo Zong, Dan Wu, Ee Peng Lim, Yin-Leng Theng, John Hedberg, Chew-Hung Chang Sep 2005

Managing Geography Learning Objects Using Personalized Project Spaces In G-Portal, Dion Hoe-Lian Goh, Aixin Sun, Wenbo Zong, Dan Wu, Ee Peng Lim, Yin-Leng Theng, John Hedberg, Chew-Hung Chang

Research Collection School Of Computing and Information Systems

The personalized project space is an important feature in G-Portal that supports individual and group learning activities. Within such a space, its owner can create, delete, and organize metadata referencing learning objects on the Web. Browsing and querying are among the functions provided to access the metadata. In addition, new schemas can be added to accommodate metadata of diverse attribute sets. Users can also easily share metadata across different projects using a “copy-and-paste” approach. Finally, a viewer to support offline viewing of personalized project content is also provided.

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On Organizing And Accessing Geospatial And Georeferenced Web Resources Using The G-Portal System, Zehua Liu, Ee Peng Lim, Yin-Leng Theng, Dion Hoe-Lian Goh, Wee-Keong Ng Sep 2005

On Organizing And Accessing Geospatial And Georeferenced Web Resources Using The G-Portal System, Zehua Liu, Ee Peng Lim, Yin-Leng Theng, Dion Hoe-Lian Goh, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

In order to organise and manage geospatial and georeferenced information on the Web making them convenient for searching and browsing, a digital portal known as G-Portal has been designed and implemented. Compared to other digital libraries, G-Portal is unique for several of its features. It maintains metadata resources in XML with flexible resource schemas. Logical groupings of metadata resources as projects and layers are possible to allow the entire metadata collection to be partitioned differently for users with different information needs. These metadata resources can be displayed in both the classification-based and map-based interfaces provided by G-Portal. G-Portal further incorporates …

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

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

Research Collection School Of Computing and Information Systems

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

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

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

Research Collection School Of Computing and Information Systems

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

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

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

Research Collection School Of Computing and Information Systems

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

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

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

Research Collection School Of Computing and Information Systems

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

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

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

Research Collection School Of Computing and Information Systems

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

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

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

Research Collection School Of Computing and Information Systems

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

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

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

Research Collection School Of Computing and Information Systems

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

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

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

Research Collection School Of Computing and Information Systems

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

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Evaluation Of Time-Varying Availability In Multi-Echelon Inventory System With Combat Damage, Hoong Chuin Lau, Huawei Song Aug 2005

Evaluation Of Time-Varying Availability In Multi-Echelon Inventory System With Combat Damage, Hoong Chuin Lau, Huawei Song

Research Collection School Of Computing and Information Systems

The models for multi-echelon inventory systems in existing literatures predominantly address failures due to reliability in peacetime. In wartime or even peacetime operational scenarios, unexpected combat damage can cause a large number of systems to be heavily damaged, to the extent that they become irreparable. In this paper, we study a multi-echelon spare parts support system under combat damage, discuss the replenishment policy and propose an approximate method to evaluate the time-varying system performance operational availability considering the effect of passivation. Experiments show our model works well and efficiently against simulation.

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Deposit-Case Attack Against Secure Roaming, Guomin Yang, Duncan S. Wong, Xiaotie Deng Jul 2005

Deposit-Case Attack Against Secure Roaming, Guomin Yang, Duncan S. Wong, Xiaotie Deng

Research Collection School Of Computing and Information Systems

A secure roaming protocol involves three parties: a roaming user, a visiting foreign server and the user’s home server. The protocol allows the user and the foreign server to establish a session key and carry out mutual authentication with the help of the home server. In the mutual authentication, user authentication is generally done in two steps. First, the user claims that a particular server is his home server. Second, that particular server is called in by the foreign server for providing a ‘credential’ which testifies the user’s claim. We present a new attacking technique which allows a malicious server …

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