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Effect Of Training Datasets On Support Vector Machine Prediction Of Protein-Protein Interactions, Siaw Ling Lo, Cong Zhong Cai, Maxey Chung, Yu Zong Chen Mar 2005

Effect Of Training Datasets On Support Vector Machine Prediction Of Protein-Protein Interactions, Siaw Ling Lo, Cong Zhong Cai, Maxey Chung, Yu Zong Chen

Research Collection School Of Computing and Information Systems

Knowledge of protein-protein interaction is useful for elucidating protein function via the concept of 'guilt-by-association'. A statistical learning method, Support Vector Machine (SVM), has recently been explored for the prediction of protein-protein interactions using artificial shuffled sequences as hypothetical noninteracting proteins and it has shown promising results (Bock, J. R., Gough, D. A., Bioinformatics 2001, 17, 455-460). It remains unclear however, how the prediction accuracy is affected if real protein sequences are used to represent noninteracting proteins. In this work, this effect is assessed by comparison of the results derived from the use of real protein sequences with that derived …

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Video Text Detection And Segmentation For Optical Character Recognition, Chong-Wah Ngo, Chi-Kwong Chan Mar 2005

Video Text Detection And Segmentation For Optical Character Recognition, Chong-Wah Ngo, Chi-Kwong Chan

Research Collection School Of Computing and Information Systems

In this paper, we present approaches to detecting and segmenting text in videos. The proposed video-text-detection technique is capable of adaptively applying appropriate operators for video frames of different modalities by classifying the background complexities. Effective operators such as the repeated shifting operations are applied for the noise removal of images with high edge density. Meanwhile, a text-enhancement technique is used to highlight the text regions of low-contrast images. A coarse-to-fine projection technique is then employed to extract text lines from video frames. Experimental results indicate that the proposed text-detection approach is superior to the machine-learning-based (such as SVM and …

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Assessment Centers In Belgium: The Results Of A Study On Their Validity And Fairness, Filip Lievens, Etienne Van Keer, Morel De Witte Mar 2005

Assessment Centers In Belgium: The Results Of A Study On Their Validity And Fairness, Filip Lievens, Etienne Van Keer, Morel De Witte

Research Collection Lee Kong Chian School Of Business

In Belgium, assessment centers have grown in popularity. Despite this growing popularity, the validity of these selection and development methods has not been examined in Belgium. Therefore, this study examines the predictive validity and fairness of an assessment center of a large bank. The sample consisted of 252 middle level managers. Results revealed that the assessment center provides a valid prediction of success in higher managerial positions. With respect to fairness, this assessment center also scores well. Virtually no significant differences between men and women and between Flemish and French speaking Belgians are found. These positive results might be explained …

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The Effects Of Ownership And Capital Structure On Board Composition And Strategic Diversification In Japanese Corporations, Toru Yoshikawa, Phillip H. Phan Mar 2005

The Effects Of Ownership And Capital Structure On Board Composition And Strategic Diversification In Japanese Corporations, Toru Yoshikawa, Phillip H. Phan

Research Collection Lee Kong Chian School Of Business

The board of directors plays an important role in solving the agency problem between shareholders and management. This paper investigates the relationships between ownership and board structure with the diversification strategy of large Japanese firms. The results show that corporate nominee directors are associated with lower levels of product diversification of their investee firms. This suggests that nominee directors in large Japanese corporations see themselves representing specific interests and therefore investors should pay attention to board composition in order to assess the level of protection they can expect to receive. Even without any apparent agency problem with management, there remains …

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Corporate Divestitures And Spinoffs In Singapore, Francis Koh, Winston T. H. Koh, Benedict S. K. Koh Mar 2005

Corporate Divestitures And Spinoffs In Singapore, Francis Koh, Winston T. H. Koh, Benedict S. K. Koh

Research Collection Lee Kong Chian School Of Business

This paper discusses the different forms of corporate divestitures, the motives for this corporate activity, and the empirical findings about their economic outcomes. A sample of corporate divestitures is also used to identify the main motivations in the Singapore context. We conclude that divestitures are carried out to achieve operational efficiency and gain incremental profitability and liquidity. Using share price data around the event-dates, we show that announcements of divestitures generally lead to significant increases in the returns of the parent company. The positive abnormal returns are related to the relative size of the divestitures and the computed accounting gains. …

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Price Limit Performance: Evidence From Transactions Data And The Limit Order Book, Soon Huat Chan, Kenneth A. Kim, S. Ghon Rhee Mar 2005

Price Limit Performance: Evidence From Transactions Data And The Limit Order Book, Soon Huat Chan, Kenneth A. Kim, S. Ghon Rhee

Research Collection Lee Kong Chian School Of Business

In recent years, organized stock exchanges with daily price limits adopted wider limits as narrower limits were criticized for jeopardizing market efficiency. This study examines the impact of a wide price limit on price discovery processes, using data from the Kuala Lumpur Stock Exchange. Specifically, examined is the impact of daily price limits on (i) information asymmetry; (ii) arrival rates of informed traders; and (iii) order imbalance. Using both trade-to-trade transaction data and the limit order book, we compile evidence that price limits do not improve information asymmetry, delays the arrival of informed traders, and exacerbates order imbalance. These results …

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On ‘‘Investment Decisions In The Theory Of Finance: Some Antinomies And Inconsistencies’’, Bert De Reyck Mar 2005

On ‘‘Investment Decisions In The Theory Of Finance: Some Antinomies And Inconsistencies’’, Bert De Reyck

Research Collection Lee Kong Chian School Of Business

In the paper “Investment Decisions in the Theory of Finance: Some antinomies and inconsistencies”, Magni [Eur. J. Operat. Res. 137 (2002) 206] shows that using the net present value rule for making investment decisions can lead to inconsistencies and antinomies. The author claims that the so-called equivalent-risk tenet of finance, whereby an investor needs to compare an investment opportunity with an asset of equivalent risk, is impossible to implement. In this paper, we show that the main thesis of this paper is incorrect, and that finance theory, when applied correctly, can be used to value investment projects by comparing assets …

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Mastaq: A Middleware Architecture For Sensor Applications With Statistical Quality Constraints, Inseok Hwang, Qi Han, Archan Misra Mar 2005

Mastaq: A Middleware Architecture For Sensor Applications With Statistical Quality Constraints, Inseok Hwang, Qi Han, Archan Misra

Research Collection School Of Computing and Information Systems

We present the design goals and functional components of MASTAQ, a data management middleware for pervasive applications that utilize sensor data. MASTAQ allows applications to specify their quality-of information (QoI) preferences (in terms of statistical metrics over the data) independent of the underlying network topology. It then achieves energy efficiency by adaptively activating and querying only the subset of sensor nodes needed to meet the target QoI bounds. We also present a closed-loop feedback mechanism based on broadcasting of activation probabilities, which allows MASTAQ to activate the appropriate number of sensors without requiring any inter-sensor coordination or knowledge of the …

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Fingerprinting Relational Databases: Schemes And Specialities, Yingjiu Li, Vipin Swarup, Sushil Jajodia Mar 2005

Fingerprinting Relational Databases: Schemes And Specialities, Yingjiu Li, Vipin Swarup, Sushil Jajodia

Research Collection School Of Computing and Information Systems

In this paper, we present a technique for fingerprinting relational data by extending Agrawal et al.'s watermarking scheme. The primary new capability provided by our scheme is that, under reasonable assumptions, it can embed and detect arbitrary bit-string marks in relations. This capability, which is not provided by prior techniques, permits our scheme to be used as a fingerprinting scheme. We then present quantitative models of the robustness properties of our scheme. These models demonstrate that fingerprints embedded by our scheme are detectable and robust against a wide variety of attacks including collusion attacks.

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Evaluation Of Mpeg-4 Ipmp Extension, Hwee Hwa Pang, Yongdong Wu Mar 2005

Evaluation Of Mpeg-4 Ipmp Extension, Hwee Hwa Pang, Yongdong Wu

Research Collection School Of Computing and Information Systems

MPEG-4 IPMPX (intellectual property management and protection extension) is the latest ISO standard which provides a flexible framework for protecting MPEG streams. The message mechanism of IPMPX enables interoperability among IPMPX-compliant devices no matter which protection methods are embedded. This paper highlights several problems in the message syntax of IPMPX: the tool delivery message IPMP_ToolES_AU is vulnerable to network attack, the authentication message IMP_Mutual_Authentication is incapable of defending against forgery attack, and the configuration message IPMP_SelectiveDecrptionInit is ambiguous and redundant. We propose a number of remedies to those problems, which can be incorporated into a corrigenda to improve the present …

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The Value Of Mobile Applications: A Utility Company Study, Fiona Fui-Hoon Nah, Keng Siau, Hong Sheng Feb 2005

The Value Of Mobile Applications: A Utility Company Study, Fiona Fui-Hoon Nah, Keng Siau, Hong Sheng

Research Collection School Of Computing and Information Systems

The value proposition of mobile applications i.e. the net value of the benefits and costs associated with the adoption and adaptation of mobile applications is discussed. A means-ends network that depicts the fundamental relationships among the objectives such as efficiency, effectiveness, customer satisfaction, security, cost, and employee acceptance, was developed. The network is useful to researchers as it highlights the issues, concerns, and values of mobile applications. The network help the managers and practitioners to achieve their companies' objectives of implementing mobile and wireless applications.

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Situational Judgment Tests And Their Predictiveness Of College Students' Success: The Influence Of Faking, Helga Peeters, Filip Lievens Feb 2005

Situational Judgment Tests And Their Predictiveness Of College Students' Success: The Influence Of Faking, Helga Peeters, Filip Lievens

Research Collection Lee Kong Chian School Of Business

There is increasing interest in using situational judgment tests (SJTs) to supplement traditional student admission procedures. An important unexplored issue is whether students can intentionally distort or fake their responses on SJTs. This study examined the fakability of an SJT of college students' performance. Two hundred ninety-three psychology students completed a cognitive test, a personality measure, and an SJT. Only for the SJT, the students were assigned to either an honest or a fake condition. The scores of students in the fake condition were significantly higher than those of students in the honest condition (d = .89). Furthermore, faking had …

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Statistical Arbitrage And Market Efficiency: Enhanced Theory, Robust Tests And Further Applications, Robert A. Jarrow, Melvyn Teo, Yiu Kuen Tse, Mitch Warachka Feb 2005

Statistical Arbitrage And Market Efficiency: Enhanced Theory, Robust Tests And Further Applications, Robert A. Jarrow, Melvyn Teo, Yiu Kuen Tse, Mitch Warachka

Research Collection Lee Kong Chian School Of Business

Statistical arbitrage enables tests of market efficiency which circumvent the joint-hypotheses dilemma. This paper makes several contributions to the statistical arbitrage framework. First, we enlarge the set of statistical arbitrage opportunities in Hogan, Jarrow, Teo, and Warachka (2004) to avoid penalizing incremental trading profits with positive deviations from their expected value. Second, we provide a statistical methodology to remedy the lack of consistency and statistical power in their Bonferroni approach. In addition, this procedure allows for autocorrelation and non-normality in trading profits. Third, we apply our tests to a wide range of trading strategies based on stock momentum, stock value, …

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Is Stellar Hedge Fund Performance For Real?, Robert Kosowski, Narayan Y. Naik, Melvyn Teo Feb 2005

Is Stellar Hedge Fund Performance For Real?, Robert Kosowski, Narayan Y. Naik, Melvyn Teo

Research Collection Lee Kong Chian School Of Business

We apply a robust bootstrap to evaluate the performance of a large universe of hedge funds. Our bootstrap estimates indicate that the performance of the top hedge funds cannot be attributed to chance alone. This is true even after adjusting for back fill bias, serial correlation, and structural breaks. Also, we find that hedge fund alpha differences persist over three year horizons. However, an investment strategy designed around this will run into difficulties as the persistence is often confined to small funds that are effectively closed to new inflows. Moreover, Bayesian estimates suggest that standard alphas may be overestimated by …

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Video Summarization And Scene Detection By Graph Modeling, Chong-Wah Ngo, Yu-Fei Ma, Hong-Jiang Zhang Feb 2005

Video Summarization And Scene Detection By Graph Modeling, Chong-Wah Ngo, Yu-Fei Ma, Hong-Jiang Zhang

Research Collection School Of Computing and Information Systems

In this paper, we propose a unified approach for video summarization based on the analysis of video structures and video highlights. Two major components in our approach are scene modeling and highlight detection. Scene modeling is achieved by normalized cut algorithm and temporal graph analysis, while highlight detection is accomplished by motion attention modeling. In our proposed approach, a video is represented as a complete undirected graph and the normalized cut algorithm is carried out to globally and optimally partition the graph into video clusters. The resulting clusters form a directed temporal graph and a shortest path algorithm is proposed …

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Analysis Of Labor Participation Behavior Of Korean Women With Dynamic Probit And Conditional Logit, Myoung-Jae Lee, Yoon-Hee Tae Feb 2005

Analysis Of Labor Participation Behavior Of Korean Women With Dynamic Probit And Conditional Logit, Myoung-Jae Lee, Yoon-Hee Tae

Research Collection School Of Economics

We analyse the dynamic labour participation behaviour of Korean women. State dependence under unobserved heterogeneity is considered, where the heterogeneity may be unrelated, pseudo-related, or arbitrarily related to regressors. Three minor methodological contributions are made: interaction terms with lagged response are allowed in dynamic conditional logit; a three-stage algorithm for dynamic probit is proposed; and treating the initial response as fixed is shown to be ill-advised. The state dependence is about 0.6 × SD(error), higher for the married or junior college-educated, and lower for women in their twenties and thirties. While education increases participation, college education has negative effects for …

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As The Bpo Business Grows, There's A Greater Focus On Metrics And Measurement, Knowledge@Smu Jan 2005

As The Bpo Business Grows, There's A Greater Focus On Metrics And Measurement, Knowledge@Smu

Knowledge@SMU

Until recently, many CEOs were grappling with issues such as whether to send back-office operations offshore to third-party providers of business process outsourcing (BPO) services, or to perform such operations in their own offshore captive centers. Today, as more and more firms move toward hybrid models of offshore outsourcing, they are looking at new management techniques, such as "virtual prowling," according to experts at Wharton and consulting firm A.T. Kearney.

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Optimal Location Of Intermodal Freight Hubs, Illia Racunica, Laura Wynter Jan 2005

Optimal Location Of Intermodal Freight Hubs, Illia Racunica, Laura Wynter

Research Collection School Of Computing and Information Systems

We present an optimization model that has been developed to address the problem of increasing the share of rail in intermodal transport through the use of hub-and-spoke type networks for freight rail. The model defined is a generalization of the hub location problem in that it allows for non-linear and concave cost functions on different segments. A linearization procedure along with two efficient variable-reduction heuristics was developed for its resolution, making use of recent results on polyhedral properties of this class of problems. Computational experience and a qualitative analysis from a case study on the Alpine freight network is provided.

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Human Mental Models Of Humanoid Robots, Sau-Lai Lee, Ivy Yee-Man Lau, Sara Kiesler, Chi-Yue Chiu Jan 2005

Human Mental Models Of Humanoid Robots, Sau-Lai Lee, Ivy Yee-Man Lau, Sara Kiesler, Chi-Yue Chiu

Research Collection School of Social Sciences

Effective communication between a person and a robot may depend on whether there exists a common ground of understanding between the two. In two experiments modelled after human-human studies we examined how people form a mental model of a robot's factual knowledge. Participants estimated the robot's knowledge by extrapolating from their own knowledge and from information about the robot's origin and language. These results suggest that designers of humanoid robots must attend not only to the social cues that robots emit but also to the information people use to create mental models of a robot.

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Analysis And Insights From A Dynamical Model Of Nuclear Plant Safety Risk, Stephen Hess, Alfonso M. Albano, John Gaertner Jan 2005

Analysis And Insights From A Dynamical Model Of Nuclear Plant Safety Risk, Stephen Hess, Alfonso M. Albano, John Gaertner

Research Collection School of Social Sciences

In this paper, we expand upon previously reported results of a dynamical systems model for the impact of plant processes and programmatic performance on nuclear plant safety risk. We utilize both analytical techniques and numerical simulations typical of the analysis of nonlinear dynamical systems to obtain insights important for effective risk management. This includes use of bifurcation diagrams to show that period doubling bifurcations and regions of chaotic dynamics can occur. We also investigate the impact of risk mitigating functions (equipment reliability and loss prevention) on plant safety risk and demonstrate that these functions are capable of improving risk to …

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A Subjective Approach To The Study Of Oligopolistic Party Systems, Riccardo Pelizzo Jan 2005

A Subjective Approach To The Study Of Oligopolistic Party Systems, Riccardo Pelizzo

Research Collection School of Social Sciences

The purpose of this paper is to present a new theory of the cartel party. My argument is straightforward. Assuming that parties are the political analog of firms, that party systems are the political analog of markets, that the shares of the electorate are the political analog of the market shares that firms control, Western European party systems share with oligopolistic markets some structural features. Yet, to know whether Western European party systems resemble oligopolistic markets, we need to know whether Western European party systems are non-competitive political markets exactly in the same way in which oligopolistic markets are not …

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A Multi-Agent Approach For Solving Optimization Problems Involving Expensive Resources, Hoong Chuin Lau, H. Wang Jan 2005

A Multi-Agent Approach For Solving Optimization Problems Involving Expensive Resources, Hoong Chuin Lau, H. Wang

Research Collection School Of Computing and Information Systems

In this paper, we propose a multi-agent approach for solving a class of optimization problems involving expensive resources, where monolithic local search schemes perform miserably. More specifically, we study the class of bin-packing problems. Under our proposed Fine-Grained Agent System scheme, rational agents work both collaboratively and selfishly based on local search and mimic physics-motivated systems. We apply our approach to a generalization of bin-packing - the Inventory Routing Problem with Time Windows - which is an important logistics problem, and demonstrate the efficiency and effectiveness of our approach.

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Do Rural Land Markets Increase Inequality? Evidence From A Chinese Province, Qian Forrest Zhang Jan 2005

Do Rural Land Markets Increase Inequality? Evidence From A Chinese Province, Qian Forrest Zhang

Research Collection School of Social Sciences

Using a 2001 provincial survey, we find that disparities in land-rights distribution have greatly increased in rural China, and the growth of land markets is directly responsible for that. The land markets tend to concentrate land in those who can more efficiently use it. This translates disparities in land-rights distribution to magnified inequality in farm income. However, such widening disparities caused by land markets have compensatory effects on overall rural inequality, as land markets tend to bring up families who would fall at the bottom of income distribution in the absence of such markets. Expansion of markets, in this case, …

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Selecting Employees For Global Assignments: Can Assessment Centers Measure Cultural Intelligence?, Michael M. Harris, Filip Lievens Jan 2005

Selecting Employees For Global Assignments: Can Assessment Centers Measure Cultural Intelligence?, Michael M. Harris, Filip Lievens

Research Collection Lee Kong Chian School Of Business

Our field is replete with attempts to measure and predict a variety of behaviors in the workplace, including task performance, contextual performance, counterproductive activity, to name but a few. One of the most recent types of behavior that organizations would like to predict is the ability to interact effectively with culturally-dissimilar others. Known by various names, including cultural intelligence or cultural adaptability, there is relatively little research as of yet regarding this topic. Nevertheless, given the growing recognition that the workplace increasingly operates in a global fashion, there is reason to believe that the literature regarding this topic will expand. …

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Strategic Management For Economic Development: Remaking The Singapore 'Model', Caroline Yeoh, Wilfred Pow Ngee How Jan 2005

Strategic Management For Economic Development: Remaking The Singapore 'Model', Caroline Yeoh, Wilfred Pow Ngee How

Research Collection Lee Kong Chian School Of Business

The dynamics of international economic competition have far-reaching policy implications for both developing and developed countries. Established industrial and trade policy regimes in most countries are under tremendous strain, and this applies even to the dynamic Newly Industrialising Economies (NIEs). The outward-oriented development strategies of the Asian NIEs, which once seemed unbeatable, have run up against protectionist barriers in the developed countries, and increasingly, against competitive pressures from other up and coming developing countries. Governments in these NIEs have had to re-examine accustomed policies and strategies, and search for alternative strategies and programs, in order to re-position their economies for …

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Assessment Centers: Recent Developments In Practice And Research, Filip Lievens, George C. Thornton Iii Jan 2005

Assessment Centers: Recent Developments In Practice And Research, Filip Lievens, George C. Thornton Iii

Research Collection Lee Kong Chian School Of Business

In an assessment center, candidates who participate in various simulation exercises are evaluated by a multiple trained assessors on job-related dimensions. Examples of commonly used simulation exercises are role-plays, presentations, in-baskets, or group discussions. For nearly fifty years, assessment centers have remained a popular approach for managerial selection and development (Spychalski, Quinones, Gaugler, & Pohley, 1997), and they have been shown to have substantial validity (Thornton & Rupp, 2004). Assessment centers are also very much an international affair as they are used around the globe (Byham, 2001; Kudisch, Avis, Fallon, Thibodeaux, Roberts, Rollier, & Rotolo, 2001; Sarges, 2001). Over the …

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Smooth Test For Density, Aurobindo Ghosh, Anil K Bera Jan 2005

Smooth Test For Density, Aurobindo Ghosh, Anil K Bera

Research Collection Lee Kong Chian School Of Business

Recently econometricians have shifted their attention from point and interval forecasts to density forecasts because at the heart of market risk measurement is the forecast of the probability density functions of various financial variables. In this paper, we propose a formal test for density forecast evaluation based on Neyman's smooth test procedure. Apart from accepting or rejecting the tested model, this approach provides specific sources (such as the location, scale and shape of the distribution) of rejection, thereby helping in deciding possible modifications of the assumed model. Our applications to S&P 500 returns indicate capturing time-varying volatility and non-gaussianity significantly …

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Theorizing, Measuring, And Predicting Knowledge Sharing Behavior In Organizations - A Social Capital Approach, Chay Yue Wah, Thomas Menkhoff, Benjamin Loh, Hans-Dieter Evers Jan 2005

Theorizing, Measuring, And Predicting Knowledge Sharing Behavior In Organizations - A Social Capital Approach, Chay Yue Wah, Thomas Menkhoff, Benjamin Loh, Hans-Dieter Evers

Research Collection Lee Kong Chian School Of Business

This study aims to understand the social and organizational factors that influence knowledge sharing. A model of knowledge management and knowledge sharing was developed inspired by the work of Nahapiet and Ghoshal. Data on demographics and various social capital measures were collected from a sample of members of a tertiary educational institution in Singapore in 2003. Reward & recognition, open-mindedness and cost concerns of knowledge hoarding turned out to be the strongest predictors of knowledge sharing rather than pro-social motives or organizational concern. Overall, the findings provide evidence for the importance of a conducive organizational climate and state-of-the art performance …

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Comment: A Selective Overview Of Nonparametric Methods In Financial Econometrics, Peter C. B. Phillips, Jun Yu Jan 2005

Comment: A Selective Overview Of Nonparametric Methods In Financial Econometrics, Peter C. B. Phillips, Jun Yu

Research Collection School Of Economics

These comments concentrate on two issues arising from Fan’s overview. The first concerns the importance of finite sample estimation bias relative to the specification and discretization biases that are emphasized in Fan’s discussion. Past research and simulations given here both reveal that finite sample effects can be more important than the other two effects when judged from either statistical or economic viewpoints. Second, we draw attention to a very different nonparametric technique that is based on computing an empirical version of the quadratic variation process. This technique is not mentioned by Fan but has many advantages and has accordingly attracted …

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Effects Of Electronic Trading On The Hang Seng Index Futures Market, Joseph K. W. Fung, Donald Lien, Yiuman Tse, Yiu Kuen Tse Jan 2005

Effects Of Electronic Trading On The Hang Seng Index Futures Market, Joseph K. W. Fung, Donald Lien, Yiuman Tse, Yiu Kuen Tse

Research Collection School Of Economics

This investigation of the switch from open-outcry trading to electronic trading on the Hang Seng Index (HSI) futures contract reveals that the bid–ask spread narrows and the futures price plays more of a role in information transmission. Factors, such as anonymity in trading and fast order execution in electronic trading, attract informed traders to the futures market, enhancing the information flow. Our results provide support for the worldwide trend of transforming open-outcry markets into electronic trading platforms

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