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Learning Causal Models For Noisy Biological Data Mining: An Application To Ovarian Cancer Detection, Ghim-Eng Yap, Ah-Hwee Tan, Hwee Hwa Pang Jul 2007

Learning Causal Models For Noisy Biological Data Mining: An Application To Ovarian Cancer Detection, Ghim-Eng Yap, Ah-Hwee Tan, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

Undetected errors in the expression measurements from highthroughput DNA microarrays and protein spectroscopy could seriously affect the diagnostic reliability in disease detection. In addition to a high resilience against such errors, diagnostic models need to be more comprehensible so that a deeper understanding of the causal interactions among biological entities like genes and proteins may be possible. In this paper, we introduce a robust knowledge discovery approach that addresses these challenges. First, the causal interactions among the genes and proteins in the noisy expression data are discovered automatically through Bayesian network learning. Then, the diagnosis of a disease based on …

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Direction-Of-Change Forecasts For Asian Equity Markets Based On Conditional Variance, Skewness And Kurtosis Dynamics: International Evidence, Peter F. Christoffersen, Francis X. Diebold, Robert S. Mariano, Anthony S. Tay, Yiu Kuen Tse Jul 2007

Direction-Of-Change Forecasts For Asian Equity Markets Based On Conditional Variance, Skewness And Kurtosis Dynamics: International Evidence, Peter F. Christoffersen, Francis X. Diebold, Robert S. Mariano, Anthony S. Tay, Yiu Kuen Tse

Research Collection School Of Economics

Recent theoretical work has revealed a direct connection between asset return volatility forecastability and asset return sign forecastability. This suggests that the pervasive volatility forecastability in equity returns could, via induced sign forecastability, be used to produce direction-of change forecasts useful for market timing. We attempt to do so in an international sample of developed equity markets, with some success, as assessed by formal probability forecast scoring rules such as the Brier score. An important ingredient is our conditioning not only on conditional mean and variance information, but also conditional skewness and kurtosis information, when forming direction-of-change forecasts.

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Indirect Inference For Dynamic Panel Models, Jun Yu Jul 2007

Indirect Inference For Dynamic Panel Models, Jun Yu

Research Collection School Of Economics

It is well-known that maximum likelihood (ML) estimation of the autoregressive parameter of a dynamic panel data model with fixed effects is inconsistent under fixed time series sample size (T) and large cross section sample size (N) asymptotics. The estimation bias is particularly relevant in practical applications when T is small and the autoregressive parameter is close to unity. The present paper proposes a general, computationally inexpensive method of bias reduction that is based on indirect inference (Gouriéroux et al., 1993), shows unbiasedness and analyzes efficiency. The method is implemented in a simple linear dynamic panel model, but has wider …

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A Corrected Plug-In Method For Quantile Interval Construction Through A Transformed Regression, Zhenlin Yang, Yiu Kuen Tse Jul 2007

A Corrected Plug-In Method For Quantile Interval Construction Through A Transformed Regression, Zhenlin Yang, Yiu Kuen Tse

Research Collection School Of Economics

We propose a corrected plug-in method for constructing confidence intervals of the conditional quantiles of an original response variable through a transformed regression with heteroscedastic errors. The interval is easy to compute. Factors affecting the magnitude of the correction are examined analytically through the special case of Box-Cox regression. Monte Carlo simulations show that the new method works well in general and is superior over the commonly used delta method and the quantile regression method. An empirical application is presented. [PUBLICATION ABSTRACT]

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Estimation Of Impulse Response Functions Using Long Autoregression, Pao Li Chang, Shinichi Sakata Jul 2007

Estimation Of Impulse Response Functions Using Long Autoregression, Pao Li Chang, Shinichi Sakata

Research Collection School Of Economics

This article proposes an alternative methodology to estimate impulse response functions without imposing parametric restrictions. The impulse responses are estimated by regressing the series of interest on estimated innovations, which are the residuals obtained from a prior-stage ‘long autoregression.’ We establish the consistency and asymptotic normality of the proposed estimator. The proposed estimator is closely related to the estimator of Jordà (2005, American Economic Review 95, 161–182). Our large sample analysis, as a byproduct, establishes the asymptotic equivalence between Jordà's estimator and our estimator, and provides justifications for the statistical inference method used in Jordà (2005).

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Organisational Learning: Conceptual Links To Individual Learning, Learning Organisation And Knowledge Management, Siu Loon Hoe Jul 2007

Organisational Learning: Conceptual Links To Individual Learning, Learning Organisation And Knowledge Management, Siu Loon Hoe

Research Collection School Of Computing and Information Systems

Organisational learning has over the years been subject of much study by scholars and managers. In the process, the organisational learning concept has been linked to many other knowledge concepts such as individual learning, learning organisation, and knowledge management. This paper draws from existing literature in organisational behaviour, human resource management, marketing, and information management, to further develop the conceptual links between organisational learning and these knowledge concepts. The paper discusses the characteristics of organisational learning and emphasises its link to individual learning, the learning organisation, and knowledge management. It contributes to the conceptual and theoretical understanding of organisational learning …

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Continuous Monitoring Of Top-K Queries Over Sliding Windows, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias Jul 2007

Continuous Monitoring Of Top-K Queries Over Sliding Windows, Kyriakos Mouratidis, Spiridon Bakiras, Dimitris Papadias

Research Collection School Of Computing and Information Systems

Given a dataset P and a preference function f, a top-k query retrieves the k tuples in P with the highest scores according to f. Even though the problem is well-studied in conventional databases, the existing methods are inapplicable to highly dynamic environments involving numerous long-running queries. This paper studies continuous monitoring of top-k queries over a fixed-size window W of the most recent data. The window size can be expressed either in terms of the number of active tuples or time units. We propose a general methodology for top-k monitoring that restricts processing to the sub-domains of the workspace …

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Cross-Lingual Query Suggestion Using Query Logs Of Different Languages, Wei Gao, Cheng Niu, Jian-Yun Nie, Ming Zhou, Jian Hu, Kam-Fai Wong, Hsiao-Wuen Hon Jul 2007

Cross-Lingual Query Suggestion Using Query Logs Of Different Languages, Wei Gao, Cheng Niu, Jian-Yun Nie, Ming Zhou, Jian Hu, Kam-Fai Wong, Hsiao-Wuen Hon

Research Collection School Of Computing and Information Systems

Query suggestion aims to suggest relevant queries for a given query, which help users better specify their information needs. Previously, the suggested terms are mostly in the same language of the input query. In this paper, we extend it to cross-lingual query suggestion (CLQS): for a query in one language, we suggest similar or relevant queries in other languages. This is very important to scenarios of cross-language information retrieval (CLIR) and cross-lingual keyword bidding for search engine advertisement. Instead of relying on existing query translation technologies for CLQS, we present an effective means to map the input query of one …

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Why Is There No Game?' Critical Success Factors In Blending An E-Learning Module Into A Knowledge Management Course: A Case Study From The Singapore Management University (Smu), Thomas Menkhoff, Yue Kee Wong, Tze Yian Thang, Donata Ty Edgardo Jul 2007

Why Is There No Game?' Critical Success Factors In Blending An E-Learning Module Into A Knowledge Management Course: A Case Study From The Singapore Management University (Smu), Thomas Menkhoff, Yue Kee Wong, Tze Yian Thang, Donata Ty Edgardo

Research Collection Lee Kong Chian School Of Business

In 2005, the authors of this essay led the development and launch of SMU's (Singapore Management University) first e-learning package on 'Knowledge Management'. This package has been integrated into the overall teaching strategy, thereby fulfilling the University's mission to be "committed to an interactive, participative and technologically-enabled learning experience"

Since its inception in 2000, SMU's educational and administrative practices are modelled after American institutions, in particular the Wharton School of the University of Pennsylvania. To support SMU's unique pedagogy, wireless technology for mobile computing is a central feature at SMU.

Against this background, the paper presents a self-critical and reflective …

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License To Share: The Ugly Side Of Creative Capitalism And The Irony Of The Commons, Warren B. Chik Jul 2007

License To Share: The Ugly Side Of Creative Capitalism And The Irony Of The Commons, Warren B. Chik

Research Collection Yong Pung How School Of Law

In the real world, capitalism has largely influenced the development of the copyright regime as it exists today. However, the emergence of a cyberspace society requires us to revisit communitarian values in the light of the unique features of virtual interaction and the changing expectations and attitudes towards the control and use of creative works. As copyright legal and technological protections continue to expand, private initiatives through creative licensing provide some relief to their restrictions.

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Juries Reborn, Mark Findlay Jul 2007

Juries Reborn, Mark Findlay

Research Collection Yong Pung How School Of Law

In most states and territories in Australia the impact of the jury on criminal justice is being systematically and radically eroded by the expansion of summary jurisdiction.

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Silence Speaks Volumes: The Effectiveness Of Reticence In Comparison To Apology And Denial For Repairing Integrity- And Competence-Based Trust Violations, Donald L. Ferrin, Peter H. Kim, Cecily D. Cooper, Kurt T. Dirks Jul 2007

Silence Speaks Volumes: The Effectiveness Of Reticence In Comparison To Apology And Denial For Repairing Integrity- And Competence-Based Trust Violations, Donald L. Ferrin, Peter H. Kim, Cecily D. Cooper, Kurt T. Dirks

Research Collection Lee Kong Chian School Of Business

Prior research on responses to trust violations has focused primarily on the effects of apology and denial. The authors extended this research by studying another type of verbal response that is often used to respond to trust violations but has not been considered in the trust literature: reticence. An accused party may use reticence in a sincere and even legitimate attempt to persuade a trustor to withhold judgment. Yet, by considering information diagnosticity and belief formation mechanisms through which verbal responses influence trust, the authors argue that reticence is a suboptimal response because it combines the least effective elements of …

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A Structuralist Model Of The Small Open Economy In The Short, Medium And Long Run, Hian Teck Hoon, Edmund S. Phelps Jun 2007

A Structuralist Model Of The Small Open Economy In The Short, Medium And Long Run, Hian Teck Hoon, Edmund S. Phelps

Research Collection School Of Economics

In open-economy macroeconomics there is a monetary model in the Keynesian tradition that is deemed serviceable for analyzing the short run and there is a nonmonetary neoclassical theory thought capable of handling the long run. But do the Keynesian and neoclassical models meet the challenges thrown out by the main events of the past few decades¡ªthe '80s shock to Europe taking the form of an external jump in real interest rates; the sort of shock experienced in the U.S. and parts of northern Europe in the second half of the '90s: the emerging prospect of new industries in the future …

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Distance To Frontier And The Big Swings Of The Unemployment Rate: What Room Is Left For Monetary Policy?, Hian Teck Hoon, Kong Weng Ho Jun 2007

Distance To Frontier And The Big Swings Of The Unemployment Rate: What Room Is Left For Monetary Policy?, Hian Teck Hoon, Kong Weng Ho

Research Collection School Of Economics

This paper builds upon Hoon and Phelps (1992, 1997) to ask how much of the evolution of the unemployment rate over several decades in country can be explained by real factors in an equilibrium model of the natural rate where country's productivity growth depends upon its distance from the world's technological leader. One motivating contemporary example includes the evolution of unemployment rates in Europe as it recovered from the second world war and caught up technologically to the US. Another example that may be less familiar to many people is Singapore (the second fastest growing economy from 1960 to 2000 …

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Continuous Nearest Neighbor Queries Over Sliding Windows, Kyriakos Mouratidis, Dimitris Papadias Jun 2007

Continuous Nearest Neighbor Queries Over Sliding Windows, Kyriakos Mouratidis, Dimitris Papadias

Research Collection School Of Computing and Information Systems

Recent research has focused on continuous monitoring of nearest neighbors (NN) in highly dynamic scenarios, where the queries and the data objects move frequently and arbitrarily. All existing methods, however, assume the Euclidean distance metric. In this paper we study k-NN monitoring in road networks, where the distance between a query and a data object is determined by the length of the shortest path connecting them. We propose two methods that can handle arbitrary object and query moving patterns, as well as fluctuations of edge weights. The first one maintains the query results by processing only updates that may invalidate …

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The Multi-Agent Data Collection In Hla-Based Simulation System, Heng-Jie Song, Zhi-Qi Shen, Chunyan Miao, Ah-Hwee Tan, Guo-Peng Zhao Jun 2007

The Multi-Agent Data Collection In Hla-Based Simulation System, Heng-Jie Song, Zhi-Qi Shen, Chunyan Miao, Ah-Hwee Tan, Guo-Peng Zhao

Research Collection School Of Computing and Information Systems

The High Level Architecture (HLA) for distributed simulation was proposed by the Defense Modeling and Simulation Office of the Department of Defense (DOD) in order to support interoperability among simulations as well as reuse of simulation models. One aspect of reusability is to collect and analyze data generated in simulation exercises, including a record of events that occur during the execution, and the states of simulation objects. In order to improve the performance of existing data collection mechanisms in the HLA simulation system, the paper proposes a multi-agent data collection system. The proposed approach adopts the hierarchical data management/organization mechanism …

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A Multi-Scale Tikhonov Regularization Scheme For Implicit Surface Modeling, Jianke Zhu, Steven C. H. Hoi, Michael R. Lyu Jun 2007

A Multi-Scale Tikhonov Regularization Scheme For Implicit Surface Modeling, Jianke Zhu, Steven C. H. Hoi, Michael R. Lyu

Research Collection School Of Computing and Information Systems

Kernel machines have recently been considered as a promising solution for implicit surface modelling. A key challenge of machine learning solutions is how to fit implicit shape models from large-scale sets of point cloud samples efficiently. In this paper, we propose a fast solution for approximating implicit surfaces based on a multi-scale Tikhonov regularization scheme. The optimization of our scheme is formulated into a sparse linear equation system, which can be efficiently solved by factorization methods. Different from traditional approaches, our scheme does not employ auxiliary off-surface points, which not only saves the computational cost but also avoids the problem …

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Electoral Laws As Political Consequences: Explaining The Origins And Change Of Electoral Institutions, Kenneth Benoit Jun 2007

Electoral Laws As Political Consequences: Explaining The Origins And Change Of Electoral Institutions, Kenneth Benoit

Research Collection School of Social Sciences

In this review article, I identify the key questions raised by the treatment of electoral systems not as causal influences on party systems but as effects or byproducts of party systems. Framing these questions in the context of the classic consequences-oriented study of electoral institutions, I first review the classic approach, which treats electoral systems as causes, and explore the potential implications when electoral systems are viewed instead as outcomes of party systems. I then survey a variety of principal explanations of the origins and change of electoral laws, followed by a focus on several of the more explicitly defined …

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Innovation Engine, Arcot Desai Narasimhalu Jun 2007

Innovation Engine, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

This paper describes a meta-model for innovation using an automobile engine as a metaphor. This innovation meta-model is used to manage a collection of innovation models. We develop an algorithm to identify innovations with potential for success using this meta-model. This meta-model can be used by corporations and individuals to identify plausible innovations at any given point in time.

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Reviewing Journal Rankings And Revisiting Peer Reviews: Editorial Perspectives, Timothy Adrian Robert Clark, Mike Wright Jun 2007

Reviewing Journal Rankings And Revisiting Peer Reviews: Editorial Perspectives, Timothy Adrian Robert Clark, Mike Wright

Research Collection Lee Kong Chian School Of Business

In this article we respond to the key points made by Macdonald and Kam (2007) in relation to journal quality and the peer review process. Whilst we appreciate that their tone is intentionally provocative, the picture they present is one of unremitting gloom and reluctant acquiescence to a system out of control. It is as if the publication process has a series of self‐supporting logics that separate it from any notion of publishing in order to benefit the discipline through the advance of knowledge and understanding. From this perspective the publishing process and the consequent content of management journals are …

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Teaching "Global Project Management" With Distributed Team Projects, Randy Weinberg, Benjamin Gan Jun 2007

Teaching "Global Project Management" With Distributed Team Projects, Randy Weinberg, Benjamin Gan

Research Collection School Of Computing and Information Systems

The education of rising professionals must keep pace with changing forces of globalization and the realities of distributed work. Students who understand the basics of global project management, teamwork and collaboration are likely to find themselves at a competitive advantage over those who do not. This article describes the experiences in an undergraduate course called Global Project Management offered concurrently at two universities, one in the U.S. and one in Singapore, and incorporating collaborative student projects.

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An Efficient Identity-Based Key Exchange Protocol With Kgs Forward Secrecy For Low-Power Devices, Robert W. Zhu, Guomin Yang, Duncan S. Wong Jun 2007

An Efficient Identity-Based Key Exchange Protocol With Kgs Forward Secrecy For Low-Power Devices, Robert W. Zhu, Guomin Yang, Duncan S. Wong

Research Collection School Of Computing and Information Systems

For an ID-based key exchange (KE) protocol, KGS forward secrecy is about the protection of previously established session keys after the master secret key of the Key Generation Server (KGS) is compromised. This is the strongest notion of forward secrecy that one can provide for an ID-based KE protocol. Among all the comparable protocols, there are only a few of them that provide this level of forward secrecy, and all of these protocols require expensive bilinear pairing operations and map-to-point hash operations that may not be suitable for implementation on low-power devices such as sensors. In this paper, we propose …

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Simplifying Cyber Foraging For Mobile Devices, Rajesh Krishna Balan, Darren Gergle, Mahadev Satyanarayanan, James Herbsleb Jun 2007

Simplifying Cyber Foraging For Mobile Devices, Rajesh Krishna Balan, Darren Gergle, Mahadev Satyanarayanan, James Herbsleb

Research Collection School Of Computing and Information Systems

Cyber foraging is the transient and opportunistic use of compute servers by mobile devices. The short market life of such devices makes rapid modification of applications for remote execution an important problem. We describe a solution that combines a "little language" for cyber foraging with an adaptive runtime system. We report results from a user study showing that even novice developers are able to successfully modify large, unfamiliar applications in just a few hours. We also show that the quality of novice-modified and expert-modified applications are comparable in most cases.

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Learning Nonparametric Kernel Matrices From Pairwise Constraints, Steven C. H. Hoi, Rong Jin, Michael R. Lyu Jun 2007

Learning Nonparametric Kernel Matrices From Pairwise Constraints, Steven C. H. Hoi, Rong Jin, Michael R. Lyu

Research Collection School Of Computing and Information Systems

Many kernel learning methods have to assume parametric forms for the target kernel functions, which significantly limits the capability of kernels in fitting diverse patterns. Some kernel learning methods assume the target kernel matrix to be a linear combination of parametric kernel matrices. This assumption again importantly limits the flexibility of the target kernel matrices. The key challenge with nonparametric kernel learning arises from the difficulty in linking the nonparametric kernels to the input patterns. In this paper, we resolve this problem by introducing the graph Laplacian of the observed data as a regularizer when optimizing the kernel matrix with …

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A Structuralist Model Of The Small Open Economy In The Short, Medium And Long Run, Hian Teck Hoon, Edmund S. Phelps Jun 2007

A Structuralist Model Of The Small Open Economy In The Short, Medium And Long Run, Hian Teck Hoon, Edmund S. Phelps

Research Collection School Of Economics

Open-economy macroeconomics contains a monetary model in the Keynesian tradition that is deemed serviceable for analyzing the short run and a nonmonetary neoclassical model thought capable of handling the long run. But do the Keynesian and neoclassical models meet the challenges thrown out by the main events of the past few decades—the ’80s shock to Europe from the sharp increase of external real interest rates; the kind of speculative shock experienced in the U.S. and parts of northern Europe in the second half of the ’90s: the prospect of new industries emerging in the future with needs for new capital; …

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Characterizing Exchange Rate Policy In East Asia: A Reconsideration, Hwee Kwan Chow, Yoonbai Kim, Wei Sun Jun 2007

Characterizing Exchange Rate Policy In East Asia: A Reconsideration, Hwee Kwan Chow, Yoonbai Kim, Wei Sun

Research Collection School Of Economics

Frankel and Wei (1994) developed and popularized a method for uncovering the implicit weights assigned to major international currencies constituting a currency basket. We extend the methodology in two dimensions: include regional competitive pressure and employ a vector autoregressive (VAR) model to overcome simultaneity bias. With these modifications, we confirm the prominent role of the US dollar in the exchange rate policy of East Asian economies beyond the short run. However, despite the high degree of commitment to nominal exchange rate stability prior to the crisis, fluctuations in most East Asian currencies are also significantly influenced by country specific shocks. …

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A Structuralist Model Of The Small Open Economy In The Short, Medium And Long Run, Hian Teck Hoon, Edmund S. Phelps Jun 2007

A Structuralist Model Of The Small Open Economy In The Short, Medium And Long Run, Hian Teck Hoon, Edmund S. Phelps

Research Collection School Of Economics

Open-economy macroeconomics contains a monetary model in the Keynesian tradition that is deemed serviceable for analyzing the short run and a nonmonetary neoclassical model thought capable of handling the long run. But do the Keynesian and neoclassical models meet the challenges thrown out by the main events of the past few decades? We first indicate that the effects of these shocks on the open economy are not well captured by either the standard Keynesian model or the standard neoclassical theory. Next we provide a careful development of a nonmonetary model of the equilibrium path of the real exchange rate, share …

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Nonlinear Filters Based On Taylor Series Expansions, Hisashi Tanizaki, Roberto S. Mariano Jun 2007

Nonlinear Filters Based On Taylor Series Expansions, Hisashi Tanizaki, Roberto S. Mariano

Research Collection School Of Economics

The nonlinear filters based on Taylor series approximation are broadly used for computational simplicity, even though their filtering estimates are clearly biased. In this paper, first, we analyze what is approximated when we apply the expanded nonlinear functions to the standard linear recursive Kalman filter algorithm. Next, since the state variable αt and αt-t are approximated as a conditional normal distribution given information up to time t - 1 (i.e., It-1) in approximation of the Taylor series expansion, it might be appropriate to evaluate each expectation by generating normal random numbers of αt and α …

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Time Capsule Signature: Efficient And Provably Secure Constructions, Bessie C. Hu, Duncan S. Wong, Qiong Huang, Guomin Yang, Xiaotie Deng Jun 2007

Time Capsule Signature: Efficient And Provably Secure Constructions, Bessie C. Hu, Duncan S. Wong, Qiong Huang, Guomin Yang, Xiaotie Deng

Research Collection School Of Computing and Information Systems

Time Capsule Signature, first formalized by Dodis and Yum in Financial Cryptography 2005, is a digital signature scheme which allows a signature to bear a (future) time t so that the signature will only be valid at time t or later, when a trusted third party called time server releases time-dependent information for checking the validity of a time capsule signature. Also, the actual signer of a time capsule signature has the privilege to make the signature valid before time t.In this paper, we provide a new security model of time capsule signature such that time server is not required …

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Mobile G-Portal Supporting Collaborative Sharing And Learning In Geography Fieldwork: An Empirical Study, Yin-Leng Theng, Kuah-Li Tan, Ee Peng Lim, Jun Zhang, Dion Hoe-Lian Goh, Kalyani Chatterjea, Chew-Hung Chang, Aixin Sun, Han Yu, Nam Hai Dang, Yuanyuan Li, Minh Chanh Vo Jun 2007

Mobile G-Portal Supporting Collaborative Sharing And Learning In Geography Fieldwork: An Empirical Study, Yin-Leng Theng, Kuah-Li Tan, Ee Peng Lim, Jun Zhang, Dion Hoe-Lian Goh, Kalyani Chatterjea, Chew-Hung Chang, Aixin Sun, Han Yu, Nam Hai Dang, Yuanyuan Li, Minh Chanh Vo

Research Collection School Of Computing and Information Systems

Integrated with G-Portal, a Web-based geospatial digital library of geography resources, this paper describes the implementation of Mobile G-Portal, a group of mobile devices as learning assistant tools supporting collaborative sharing and learning for geography fieldwork. Based on a modified Technology Acceptance Model and a Task-Technology Fit model, an initial study with Mobile G-Portal was conducted involving 39 students in a local secondary school. The findings suggested positive indication of acceptance of Mobile G-Portal for geography fieldwork. The paper concludes with a discussion on technological challenges, recommendations for refinement of Mobile G-Portal, and design implications in general for digital libraries …

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