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Articles 8851 - 8880 of 9399

Full-Text Articles in Physical Sciences and Mathematics

Prediction Of Rna-Binding Proteins From Primary Sequence By A Support Vector Machine Approach., Lian Yi Han, Cong Zhong Cai, Siaw Ling Lo, Maxey Chung, Yu Zong Chen Mar 2004

Prediction Of Rna-Binding Proteins From Primary Sequence By A Support Vector Machine Approach., Lian Yi Han, Cong Zhong Cai, Siaw Ling Lo, Maxey Chung, Yu Zong Chen

Research Collection School Of Computing and Information Systems

Elucidation of the interaction of proteins with different molecules is of significance in the understanding of cellular processes. Computational methods have been developed for the prediction of protein-protein interactions. But insufficient attention has been paid to the prediction of protein-RNA interactions, which play central roles in regulating gene expression and certain RNA-mediated enzymatic processes. This work explored the use of a machine learning method, support vector machines (SVM), for the prediction of RNA-binding proteins directly from their primary sequence. Based on the knowledge of known RNA-binding and non-RNA-binding proteins, an SVM system was trained to recognize RNA-binding proteins. A total …

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Knowledge-Based Support In A Group Decision-Making Context: An Expert-Novice Comparison, Fiona Fui-Hoon Nah, I. Benbasat Mar 2004

Knowledge-Based Support In A Group Decision-Making Context: An Expert-Novice Comparison, Fiona Fui-Hoon Nah, I. Benbasat

Research Collection School Of Computing and Information Systems

This research examines the use of knowledge-based and explanation facilities to support group decision making of experts versus novices. Consistent with predictions from the persuasion literature, our results show that experts exhibit a higher level of criticality and involvement in their area of expertise; this not only decreases their likelihood of being persuaded by a knowledge-based system, but also accounts for a lower group consensus among experts as compared to novices. Novices are more easily persuaded by the system and find the system to be more useful than experts do. This research integrates theories from the persuasion literature to understand …

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A Smart-Card-Enabled Privacy Preserving E-Prescription System, Yanjiang Yang, Xiaoxi Han, Feng Bao, Robert H. Deng Mar 2004

A Smart-Card-Enabled Privacy Preserving E-Prescription System, Yanjiang Yang, Xiaoxi Han, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

Within the overall context of protection of health care information, privacy of prescription data needs special treatment. First, the involvement of diverse parties, especially nonmedical parties in the process of drug prescription complicates the protection of prescription data. Second, both patients and doctors have privacy stakes in prescription, and their privacy should be equally protected. Third, the following facts determine that prescription should not be processed in a truly anonymous manner: certain involved parties conduct useful research on the basis of aggregation of prescription data that are linkable with respect to either the patients or the doctors; prescription data has …

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An Information-Theoretic Framework For Optimal Location Tracking In Multi-System 4g Wireless Networks, Archan Misra, Abhishek Roy, Sajal K. Das Mar 2004

An Information-Theoretic Framework For Optimal Location Tracking In Multi-System 4g Wireless Networks, Archan Misra, Abhishek Roy, Sajal K. Das

Research Collection School Of Computing and Information Systems

An information-theoretic framework is developed for optimal location management in multisystem, fourth generation (4G) wireless networks. The framework envisions that each individual subsystem operates fairly independently, and does not require public knowledge of individual subnetwork topologies. To capture the variation in paging and location update costs in this heterogeneous environment, the location management problem is formulated in terms of a new concept of weighted entropy. The update process is based on the Lempel-Ziv compression algorithms, which are applied to a vector-valued sequence consisting of both the mobile's movement pattern and its session activity state. Three different tracking strategies which differ …

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An Automated Algorithm For Extracting Website Skeleton, Zehua Liu, Wee-Keong Ng, Ee Peng Lim Mar 2004

An Automated Algorithm For Extracting Website Skeleton, Zehua Liu, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

The huge amount of information available on the Web has attracted many research efforts into developing wrappers that extract data from webpages. However, as most of the systems for generating wrappers focus on extracting data at page-level, data extraction at site-level remains a manual or semi-automatic process. In this paper, we study the problem of extracting website skeleton, i.e. extracting the underlying hyperlink structure that is used to organize the content pages in a given website. We propose an automated algorithm, called the Sew algorithm, to discover the skeleton of a website. Given a page, the algorithm examines hyperlinks in …

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Security Analysis Of Some Proxy Signature, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng Mar 2004

Security Analysis Of Some Proxy Signature, Guilin Wang, Feng Bao, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

A proxy signature scheme allows an entity to delegate his/her signing capability to another entity in such a way that the latter can sign messages on behalf of the former. Such schemes have been suggested for use in a number of applications, particularly in distributed computing where delegation of rights is quite common. Followed by the first schemes introduced by Mambo, Usuda and Okamoto in 1996, a number of new schemes and improvements have been proposed. In this paper, we present a security analysis of four such schemes newly proposed. By successfully identifying several interesting forgery attacks, we show that …

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Hiding Data Accesses In Steganographic File System, Xuan Zhou, Hwee Hwa Pang, Kian-Lee Tan Mar 2004

Hiding Data Accesses In Steganographic File System, Xuan Zhou, Hwee Hwa Pang, Kian-Lee Tan

Research Collection School Of Computing and Information Systems

To support ubiquitous computing, the underlying data have to be persistent and available anywhere-anytime. The data thus have to migrate from devices local to individual computers, to shared storage volumes that are accessible over open network. This potentially exposes the data to heightened security risks. We propose two mechanisms, in the context of a steganographic file system, to mitigate the risk of attacks initiated through analyzing data accesses from user applications. The first mechanism is intended to counter attempts to locate data through updates in between snapshots - in short, update analysis. The second mechanism prevents traffic analysis - identifying …

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Effects Of Query Complexity And Learning On Novice User Query Performance With Conceptual And Logical Database Interfaces, Keng Siau, Hock Chuan Chan, Kwok Kee Wei Mar 2004

Effects Of Query Complexity And Learning On Novice User Query Performance With Conceptual And Logical Database Interfaces, Keng Siau, Hock Chuan Chan, Kwok Kee Wei

Research Collection School Of Computing and Information Systems

Users see the database interface as the database system. A good interface enables them to formulate queries better. The semantics communicated through the interface can be classified according to abstraction levels, such as the conceptual and logical levels. With the conceptual interface, interaction is in terms of real-world concepts such as entities, objects and relationships. Current user-database interaction is mainly based on the logical interface, where interaction is in terms of abstract database concepts such as relations and joins. Many researchers argue that end users will perform better with the conceptual interface. This research tested this claim, as well as …

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Spatial Queries In The Presence Of Obstacles, Jun Zhang, Dimitris Papadias, Kyriakos Mouratidis, Manli Zhu Mar 2004

Spatial Queries In The Presence Of 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 utilizes the Euclidean distance metric assuming that points in space are directly reachable. 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 neighbors, e-distance joins and closest pairs, considering that both data objects and obstacles are indexed by R-trees. The effectiveness of the proposed solutions is verified …

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Group Nearest Neighbor Queries, Dimitris Papadias, Qiongmao Shen, Yufei Tao, Kyriakos Mouratidis Mar 2004

Group Nearest Neighbor Queries, Dimitris Papadias, Qiongmao Shen, Yufei Tao, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

Given two sets of points P and Q, a group nearest neighbor (GNN) query retrieves the point(s) of P with the smallest sum of distances to all points in Q. Consider, for instance, three users at locations q1 , q2 and q3 that want to find a meeting point (e.g., a restaurant); the corresponding query returns the data point p that minimizes the sum of Euclidean distances |pqi| for 1 ≤i ≤3. Assuming that Q fits in memory and P is indexed by an R-tree, we propose several algorithms for finding the group nearest neighbors efficiently. As a second step, …

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Efficient Group Pattern Mining Using Data Summarization, Yida Wang, Ee Peng Lim, San-Yih Hwang Mar 2004

Efficient Group Pattern Mining Using Data Summarization, Yida Wang, Ee Peng Lim, San-Yih Hwang

Research Collection School Of Computing and Information Systems

In group pattern mining, we discover group patterns from a given user movement database based on their spatio-temporal distances. When both the number of users and the logging duration are large, group pattern mining algorithms become very inefficient. In this paper, we therefore propose a spherical location summarization method to reduce the overhead of mining valid 2-groups. In our experiments, we show that our group mining algorithm using summarized data may require much less execution time than that using non-summarized data.

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Clash: A Protocol For Internet-Scale Utility-Oriented Distributed Computing, Archan Misra, Paul Castro, Jinwon Lee Mar 2004

Clash: A Protocol For Internet-Scale Utility-Oriented Distributed Computing, Archan Misra, Paul Castro, Jinwon Lee

Research Collection School Of Computing and Information Systems

Distributed hash table (DHT) overlay networks offer an efficient and robust technique for wire-area data storage and queries. Workload from real applications that use DHT networks will likely exhibit significant skews that can result in bottlenecks and failures that limit the overall scalability of the DHT approach. We present the content and load-aware scalable hashing (CLASH) protocol that can enhance the load distribution behavior of a DHT. CLASH relies on a variable-length identifier key scheme, where the length of any individual key is a function of load. CLASH uses variable-length keys to cluster content-related objects on single nodes to achieve …

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Tool Support For Model Based Architectural Design For Automotive Control Systems, Kevin Steppe Mar 2004

Tool Support For Model Based Architectural Design For Automotive Control Systems, Kevin Steppe

Research Collection School Of Computing and Information Systems

In conjunction with Ford Motor Company, we built a tool to support multilevel architectural design. The tool, called Synergy, allows Ford to visually design architectures of vehicle control components. The components are imported from existing Simulink models; then the tool automatically generates a detailed view showing all required connections and ports. The resulting model is exported to Simulink for further analysis. In this paper we describe the conceptual and technical challenges encountered in building Synergy and our design choices for solving them.

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Suppression Of Polarization Switching In Birefringent Antiresonant Reflecting Optical Waveguide Vertical-Cavity Surface-Emitting Lasers, N. S. Chen, S. F. Yu, Chyng Wen Tee Mar 2004

Suppression Of Polarization Switching In Birefringent Antiresonant Reflecting Optical Waveguide Vertical-Cavity Surface-Emitting Lasers, N. S. Chen, S. F. Yu, Chyng Wen Tee

Research Collection Lee Kong Chian School Of Business

Influence of birefringence on the multimode operation of antiresonant reflecting optical waveguide (ARROW) vertical-cavity surface-emitting lasers (VCSELs) is analyzed. It can be shown that polarization switching is mainly due to thermal lensing effects. Hence, a new design rule is proposed to optimize the dimensions of ARROW for the suppression of polarization switching. Using the optimized design, the maximum single-polarization output power of VCSELs can be tripled. In addition, it is shown that the performance of the optimized ARROW VCSELs will not be deteriorated by the uncertainty of birefringence.

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Tool Support For Two-Tiered Architectural Design For Automotive Control Systems, Kevin Steppe, Greg Bylenok, David Garlan, Bradley Schmerl, Kanat Abirov, Nataliya Shevchenko Jan 2004

Tool Support For Two-Tiered Architectural Design For Automotive Control Systems, Kevin Steppe, Greg Bylenok, David Garlan, Bradley Schmerl, Kanat Abirov, Nataliya Shevchenko

Research Collection School Of Computing and Information Systems

An attractive approach to architecture-based design is to structure the development process into two tiers. The top tier represents the abstract design (or architecture) of a system in terms of abstract components. The bottom tier refines that design by making specific implementation decisions, such as platform, middleware, and component implementations. While attractive in principle, there has been relatively little industrial-based experience to shed light on problems and solutions involved in such an approach. In this paper we describe our experience in developing tools to introduce a two-tiered model-based approach to the design of Ford Motor Company’s automotive control systems, highlighting …

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Parameter Selection In Genetic Algorithms, Onur Boyabatli, Ihsan Sabuncuoglu Jan 2004

Parameter Selection In Genetic Algorithms, Onur Boyabatli, Ihsan Sabuncuoglu

Research Collection Lee Kong Chian School Of Business

In this study, we provide a new taxonomy of parameters of genetic algorithms (GA), structural and numerical parameters, and analyze the effect of numerical parameters on the performance of GA based simulation optimization applications with experimental design techniques. Appropriate levels of each parameter are proposed for a particular problem domain. Controversial to existing literature on GA, our computational results reveal that in the case of a dominant set of decision variable the crossover operator does not have a significant impact on the performance measures, whereas high mutation rates are more suitable for GA applications.

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Java-Based Digital Library Portal For Geography Education, Zehua Liu, Hai Yuan, Ee Peng Lim, Ming Yin, Dion Hoe-Lian Goh, Yin-Leng Theng, Wee-Keong Ng Jan 2004

Java-Based Digital Library Portal For Geography Education, Zehua Liu, Hai Yuan, Ee Peng Lim, Ming Yin, Dion Hoe-Lian Goh, Yin-Leng Theng, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

G-Portal is a Java-based digital library system for managing the metadata of geography related resources on the Web. In addition to providing a flexible repository subsystem to accommodate metadata of different formats using XML and XML Schemas, G-Portal organizes metadata into projects and layers, and supports an integrated and synchronized classification and map-based interfaces over the stored metadata. G-Portal also includes a classification subsystem that creates category structures and classifies metadata resources into categories based on user-specified classification schemas. Furthermore, G-Portal users can annotate resources and make their annotations available to others. In this paper, we describe the design and …

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Supply Chains Integration: Architecture And Enabling Technologies, Keng Siau, Yuhong Tian Jan 2004

Supply Chains Integration: Architecture And Enabling Technologies, Keng Siau, Yuhong Tian

Research Collection School Of Computing and Information Systems

An effective and efficient supply chain is vital to the competitiveness and the survival of an organization. With the emergence of the e-business era, supply chain systems need to be able to extend beyond the traditional boundaries. This paper proposes integrated supply chain architecture (SCA) that combines the benefits of Enterprise Resource Planning (ERP) and the various supply chain applications. Some necessary criteria for an integrated supply chain include completeness, security, flexibility, scalability, and interoperability. The enabling technologies for such a supply chain system include XML, DCOM, CORBA, SOAP, Net, and Semantic Web. Wireless and mobile technologies could further extend …

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Qos Routing Optimization Strategy Using Genetic Algorithm In Optical Fiber Communication Networks, Zhaoxia Wang, Zengqiang Chen, Zhuzhi Yuan Jan 2004

Qos Routing Optimization Strategy Using Genetic Algorithm In Optical Fiber Communication Networks, Zhaoxia Wang, Zengqiang Chen, Zhuzhi Yuan

Research Collection School Of Computing and Information Systems

This paper describes the routing problems in optical fiber networks, defines five constraints, induces and simplifies the evaluation function and fitness function, and proposes a routing approach based on the genetic algorithm, which includes an operator [OMO] to solve the QoS routing problem in optical fiber communication networks. The simulation results show that the proposed routing method by using this optimal maintain operator genetic algorithm (OMOGA) is superior to the common genetic algorithms (CGA). It not only is robust and efficient but also converges quickly and can be carried out simply, that makes it better than other complicated GA.

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Evaluating The Usability Of A Group Support System Using Co-Discovery, Keng Siau Jan 2004

Evaluating The Usability Of A Group Support System Using Co-Discovery, Keng Siau

Research Collection School Of Computing and Information Systems

Group Support Systems (GSSs) have emerged as a new type of information system to aid group decision-making. With the proliferation of such systems in organizations, evaluation of GSSs is becoming increasingly important. This paper reports the evaluation of an existing GSS. Our usability framework consists of nine dimensions: visual clarity, consistency, compatibility, informative feedback, explicitness, flexibility and control, error prevention and correction, ease of learning, and ease of use. We make use of the co-discovery method where teams of two participants perform tasks together while being observed. The study involves questionnaires and interview sessions. The strengths and weaknesses of the …

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Deviance Information Criterion For Comparing Stochastic Volatility Models, Andreas Berg, Renate Meyer, Jun Yu Jan 2004

Deviance Information Criterion For Comparing Stochastic Volatility Models, Andreas Berg, Renate Meyer, Jun Yu

Research Collection School Of Economics

Bayesian methods have been efficient in estimating parameters of stochastic volatility models for analyzing financial time series. Recent advances made it possible to fit stochastic volatility models of increasing complexity, including covariates, leverage effects, jump components, and heavy-tailed distributions. However, a formal model comparison via Bayes factors remains difficult. The main objective of this article is to demonstrate that model selection is more easily performed using the deviance information criterion (DIC). It combines a Bayesian measure of fit with a measure of model complexity. We illustrate the performance of DIC in discriminating between various different stochastic volatility models using simulated …

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Analysis Of A Yield Management Model For On Demand Computing Centers, Yezekael Hayel, Laura Wynter, Parijat Dube Jan 2004

Analysis Of A Yield Management Model For On Demand Computing Centers, Yezekael Hayel, Laura Wynter, Parijat Dube

Research Collection School Of Computing and Information Systems

The concept of yield management for IT infrastructures, and in particular for on demand IT utilities was recently introduced in [17]. The present paper provides a detailed analysis of that model, both in simplified cases where an analytical analysis is possible, and numerically on larger problem instances, and confirms the significant revenue benefit that can accrue through use of yield management in an IT on demand operating environment.

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Powerful Change Part 2: Reducing The Power Demands Of Mobile Devices, Rajesh Krishna Balan Jan 2004

Powerful Change Part 2: Reducing The Power Demands Of Mobile Devices, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

Consumers expect their mobile devices to be small and light, have a decent battery lifetime, and still be powerful enough to run all their desired applications. The need to satisfy such consumer demands has driven mobile-device manufacturers to make products (such as PDAs and cell phones) that match these needs. However, this inevitably requires tradeoffs. Building smaller, lighter devices requires sacrificing the device's battery capacity because battery technology is still fairly dense and heavy, and contributes most of a mobile device's size and weight. But, mobile devices with the required resources to run useful desktop applications need additional battery power …

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A Secure And Privacy Enhanced Location-Based Service Transaction Protocol In Ubiquitous Computing Environment, Konidala Divyan, Robert H. Deng, Jianying Zhou, Kwanjo Kim Jan 2004

A Secure And Privacy Enhanced Location-Based Service Transaction Protocol In Ubiquitous Computing Environment, Konidala Divyan, Robert H. Deng, Jianying Zhou, Kwanjo Kim

Research Collection School Of Computing and Information Systems

Nowadays mobile phones and PDAs are part and parcel of our lives. By carrying a portable mobile device with us all the time we are already living in partial Pervasive Computing Environment (PCE) that is waiting to be exploited very soon. One of the advantages of pervasive computing is that it strongly supports the deployment of Location-Based Service(s) (LBSs). In PCE, there would be many competitive service providers (SPs) trying to sell different or similar LBSs to users. In order to avail a particular service, it becomes very di#cult for a low-computing and resourcepoor mobile device to handle many such …

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Web Usage Mining: Algorithms And Results, Ee Peng Lim, Yew-Kwong Woon, Wee-Keong Ng Jan 2004

Web Usage Mining: Algorithms And Results, Ee Peng Lim, Yew-Kwong Woon, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

No abstract provided.

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Viscors: A Visual-Content Recommender For The Mobile Web, Chan Young Kim, Jae Kyu Lee, Yoon Ho Cho, Deok Hwan Kim Jan 2004

Viscors: A Visual-Content Recommender For The Mobile Web, Chan Young Kim, Jae Kyu Lee, Yoon Ho Cho, Deok Hwan Kim

Research Collection School Of Computing and Information Systems

Current search methods for mobile-Web content can be frustrating to use. To shorten searches for cell phone wallpaper images, VISCORS combines collaborative filtering with content-based image retrieval. An increasing selection of content is becoming available in the mobile-Web environment, where users navigate the Web using wireless devices such as cell phones and PDAs. The fast growth and excellent prospects of the mobile-Web content market have attracted many content providers.

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Logistics Outsourcing And 3pl Challenges, Michelle L. F. Cheong Jan 2004

Logistics Outsourcing And 3pl Challenges, Michelle L. F. Cheong

Research Collection School Of Computing and Information Systems

Logistics has been an important part of every economy and every business entity. The worldwide trend in globalization has led to many companies outsourcing their logistics function to Third-Party Logistics (3PL) companies, so as to focus on their core competencies. This paper attempts to broadly identify and categorize the challenges faced by 3PL companies and discover potential gaps for future research. Some of the challenges will be related with the experience and information collected from interviews with two 3PL companies.

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Design And Analysis Of Cylindrical Antiresonant Reflecting Optical Waveguide, Chyng Wen Tee, S. F. Yu Dec 2003

Design And Analysis Of Cylindrical Antiresonant Reflecting Optical Waveguide, Chyng Wen Tee, S. F. Yu

Research Collection Lee Kong Chian School Of Business

A field-transfer matrix method is developed to analyze the modal characteristics of cylindrical multilayered waveguides with axis-symmetric geometry. A new design rule for cylindrical antiresonant reflecting optical waveguides (ARROWs), based on a three-step design process, is also proposed to minimize the radiation loss of the fundamental leaky mode. In addition, a simple approach is suggested to estimate the optimum core diameter of the cylindrical ARROWs for optimum radiation loss and radiation loss margin. Hence, it can be shown that an extra high index cladding layer is good enough to reduce the radiation loss as well as to maintain a reasonably …

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Paper For An Educational Digital Library, Dion Hoe-Lian Goh, Yin-Leng Theng, Ming Yin, Ee Peng Lim Dec 2003

Paper For An Educational Digital Library, Dion Hoe-Lian Goh, Yin-Leng Theng, Ming Yin, Ee Peng Lim

Research Collection School Of Computing and Information Systems

GeogDL is a digital library of geography examination resources designed to assist students in revising for a national geography examination in Singapore. As part of an iterative design process, we carried out participatory design and brainstorming with student and teacher design partners. The first study involved prospective student design partners. In response to the first study, we describe in this paper an implementation of PAPER – Personalised Adaptive Pathways for Exam Resources – a new bundle of personalized, interactive services containing a mock exam and a personal coach. The mock exam provides a simulation of the actual geography examination while …

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A Fit-Gap Analysis Of E-Business Curricula Vs. Industry Need, S. Davis, Keng Siau, K. Dhenuvakonda Dec 2003

A Fit-Gap Analysis Of E-Business Curricula Vs. Industry Need, S. Davis, Keng Siau, K. Dhenuvakonda

Research Collection School Of Computing and Information Systems

The alignment of e-business academic programs with the e-business market is examined using a fit-gap analysis. Two high-end business schools, ranked independently by US News and Business Week, were chosen as sample. A total of 391 different e-commerce courses were identified, which were classified into 24 categories. Out of these, there are two broad and distinct tracks in e-business curricula, with one track paving the way for an e-business career with a prevailing focus on the business aspect and the other track leading to a career focusing on technology and Web-based systems development. Industry demand for e-business professionals and the …

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