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Personality Scale Validities Increase Throughout Medical School, Filip Lievens, Deniz S. Ones, Stephan Dilchert Nov 2009

Personality Scale Validities Increase Throughout Medical School, Filip Lievens, Deniz S. Ones, Stephan Dilchert

Research Collection Lee Kong Chian School Of Business

Admissions and personnel decisions rely on stable predictor-criterion relationships. The authors studied the validity of Big Five personality factors and their facets for predicting academic performance in medical school across multiple years, investigating whether criterion-related validities change over time. In this longitudinal investigation, an entire European country's 1997 cohort of medical students was studied throughout their medical school career (Year 1, N = 627; Year 7, N = 306). Over time, extraversion, openness, and conscientiousness factor and facet scale scores showed increases in operational validity for predicting grade point averages. Although there may not be any advantages to being open …

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Mining Hierarchical Scenario-Based Specifications, David Lo, Shahar Maoz Nov 2009

Mining Hierarchical Scenario-Based Specifications, David Lo, Shahar Maoz

Research Collection School Of Computing and Information Systems

Scalability over long traces, as well as comprehensibility and expressivity of results, are major challenges for dynamic analysis approaches to specification mining. In this work we present a novel use of object hierarchies over traces of inter-object method calls, as an abstraction/refinement mechanism that enables user-guided, top-down or bottom-up mining of layered scenario-based specifications, broken down by hierarchies embedded in the system under investigation. We do this using data mining methods that provide statistically significant sound and complete results modulo user-defined thresholds, in the context of Damm and Harel’s live sequence charts (LSC); a visual, modal, scenario-based, inter-object language. Thus, …

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Trust Relationship Prediction Using Online Product Review Data, Nan Ma, Ee Peng Lim, Viet-An Nguyen, Aixin Sun Nov 2009

Trust Relationship Prediction Using Online Product Review Data, Nan Ma, Ee Peng Lim, Viet-An Nguyen, Aixin Sun

Research Collection School Of Computing and Information Systems

Trust between users is an important piece of knowledge that can be exploited in search and recommendation.Given that user-supplied trust relationships are usually very sparse, we study the prediction of trust relationships using user interaction features in an online user generated review application context. We show that trust relationship prediction can achieve better accuracy when one adopts personalized and cluster-based classification methods. The former trains one classifier for each user using user-specific training data. The cluster-based method first constructs user clusters before training one classifier for each user cluster. Our proposed methods have been evaluated in a series of experiments …

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Trust-Oriented Composite Services Selection And Discovery, Lei Li, Yan Wang, Ee Peng Lim Nov 2009

Trust-Oriented Composite Services Selection And Discovery, Lei Li, Yan Wang, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In Service-Oriented Computing (SOC) environments, service clients interact with service providers for consuming services. From the viewpoint of service clients, the trust level of a service or a service provider is a critical issue to consider in service selection and discovery, particularly when a client is looking for a service from a large set of services or service providers. However, a service may invoke other services offered by different providers forming composite services. The complex invocations in composite services greatly increase the complexity of trust-oriented service selection and discovery. In this paper, we propose novel approaches for composite service representation, …

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Reaching Out And Beyond: A Review Of Southeast Asian Writing In English [Book Review], Kirpal Singh Nov 2009

Reaching Out And Beyond: A Review Of Southeast Asian Writing In English [Book Review], Kirpal Singh

Research Collection School of Social Sciences

No abstract provided.

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Static Validation Of C Preprocessor Macros, Andreas Saebjornsen, Lingxiao Jiang, Daniel Quinlan, Zhendong Su Nov 2009

Static Validation Of C Preprocessor Macros, Andreas Saebjornsen, Lingxiao Jiang, Daniel Quinlan, Zhendong Su

Research Collection School Of Computing and Information Systems

The widely used C preprocessor (CPP) is generally considered a source of difficulty for understanding and maintaining C/C++ programs. The main reason for this difficulty is CPP’s purely lexical semantics, i.e., its treatment of both input and output as token streams. This can easily lead to errors that are difficult to diagnose, and it has been estimated that up to 20% of all macros are erroneous. To reduce such errors, more restrictive, replacement languages for CPP have been proposed to limit expanded macros to be valid C syntactic units. However, there is no practical tool that can effectively validate CPP …

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Trade, Growth And Increasing Returns To Infrastructure: The Role Of The Sophisticated Monopolist, Ashok S. Guha, Brishti Guha Nov 2009

Trade, Growth And Increasing Returns To Infrastructure: The Role Of The Sophisticated Monopolist, Ashok S. Guha, Brishti Guha

Research Collection School Of Economics

Equilibrium in international trade with increasing returns in infrastructure depends on whether the infrastructure provider is “naïve” or sophisticated. A monopolist produces infrastructure under decreasing cost using fixed equipment. Unlike similar work, we derive a unique closed-economy equilibrium. In a small open economy, with “naïve” infrastructure provider(s), multiple equilibria obtain. The industrial export potential of the economy depends on unexhausted economies of scale, and equilibria are possible where manufactures are exported despite an autarky price higher than the world price. With a sophisticated infrastructure provider, even an open economy has a unique equilibrium, which, at least as long as economies …

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Bias In The Estimation Of The Mean Reversion Parameter In Continuous Time Models, Jun Yu Nov 2009

Bias In The Estimation Of The Mean Reversion Parameter In Continuous Time Models, Jun Yu

Research Collection School Of Economics

It is well known that for continuous time models with a linear drift standard estimation methods yield biased estimators for the mean reversion parameter both in nite discrete samples and in large in-…ll samples. In this paper, we obtain two expressions to approximate the bias of the least squares/maximum likelihood estimator of the mean reversion parameter in the Ornstein-Uhlenbeck process with a known long run mean when discretely sampled data are available. The first expression mimics the bias formula of Marriott and Pope (1954) for the discrete time model. Simulations show that this expression does not work satisfactorily when the …

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Dating The Timeline Of Financial Bubbles During The Subprime Crisis, Peter C. B. Phillips, Jun Yu Nov 2009

Dating The Timeline Of Financial Bubbles During The Subprime Crisis, Peter C. B. Phillips, Jun Yu

Research Collection School Of Economics

A new recursive regression methodology is introduced to analyze the bubble characteristics of various financial time series during the subprime crisis. The methods modify a technique proposed in Phillips, Wu, and Yu (2011) and provide a technology for identifying bubble behavior with consistent dating of their origination and collapse. The tests serve as an early warning diagnostic of bubble activity and a new procedure is introduced for testing bubble migration across markets. Three relevant financial series are investigated, including a financial asset price (a house price index), a commodity price (the crude oil price), and one bond price (the spread …

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Explosive Behavior In The 1990s Nasdaq: When Did Exuberance Escalate Asset Values?, Peter C. B. Phillips, Yangru Wu, Jun Yu Nov 2009

Explosive Behavior In The 1990s Nasdaq: When Did Exuberance Escalate Asset Values?, Peter C. B. Phillips, Yangru Wu, Jun Yu

Research Collection School Of Economics

A recursive test procedure is suggested that provides a mechanism for testing explosive behavior, date-stamping the origination and collapse of economic exuberance, and providing valid confidence intervals for explosive growth rates. The method involves the recursive implementation of a right-side unit root test and a sup test, both of which are easy to use in practical applications, and some new limit theory for mildly explosive processes. The test procedure is shown to have discriminatory power in detecting periodically collapsing bubbles, thereby overcoming a weakness in earlier applications of unit root tests for economic bubbles. Some asymptotic properties of the Evans …

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Econometric Analysis Of Continuous Time Models: A Survey Of Peter Philip’S Work And Some New Results, Jun Yu Nov 2009

Econometric Analysis Of Continuous Time Models: A Survey Of Peter Philip’S Work And Some New Results, Jun Yu

Research Collection School Of Economics

Econometric analysis of continuous time models has drawn the attention of Peter Phillips for nearly 40 years, resulting in many important publications by him. In these publications he has dealt with a wide range of continuous time models and econometric problems, from univariate equations to systems of equations, from asymptotic theory to nite sample issues, from parametric models to nonparametric models, from identication problems to estimation and inference problems, from stationary models to nonstationary and nearly nonstationary models. This paper provides an overview of Peter Phillips' contributions in the continuous time econometrics literature. We review the problems that have been …

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Forecasting Realized Volatility Using A Nonnegative Semiparametric Model, Daniel P. A. Preve, Anders Eriksson, Jun Yu Nov 2009

Forecasting Realized Volatility Using A Nonnegative Semiparametric Model, Daniel P. A. Preve, Anders Eriksson, Jun Yu

Research Collection School Of Economics

This paper introduces a parsimonious and yet flexible nonnegative semiparametric model to forecast volatility. The new model extends the linear nonnegative autoregressive model of Barndorff-Nielsen and Shephard (2001) and Nielsen and Shephard (2003) by way of a Box-Cox transformation. It is semiparametric in the sense that the dependency structure and the distributional form of its error component are left unspecified. The statistical properties of the model are discussed and a novel estimation method is proposed. Its out-of-sample performance is evaluated against a number of standard methods, using data on S&P 500 monthly realized volatilities. The competing models include the exponential …

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The Effectiveness Of Acceptances Communicated By Electronic Means, Or – Does The Postal Acceptance Rule Apply To Email, Eliza Mik Nov 2009

The Effectiveness Of Acceptances Communicated By Electronic Means, Or – Does The Postal Acceptance Rule Apply To Email, Eliza Mik

Research Collection Yong Pung How School Of Law

The ‘traditional’ classi?cation into ‘instantaneous’ and ‘non-instantaneous’ methods of communication must be abandoned. As all Internet transmissions are instantaneous, the choice between the principle of receipt and the postal exception must be based on other criteria. The focus must be shifted from communication devices to the characteristics of the communication process. The latter resembles either dealings face-to-face or dealings at a distance. This simple division should remain the basis for all analyses. Instantaneity and control are two of many characteristics of face-to-face dealings and are not the only factors to be taken into account when making the choice between the …

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Regulatory Exposure Of Deceptive Marketing And Its Impact On Firm Value, Martha Myslinski Tipton, Sundar G. Bharadwaj, Diana C. Robertson Nov 2009

Regulatory Exposure Of Deceptive Marketing And Its Impact On Firm Value, Martha Myslinski Tipton, Sundar G. Bharadwaj, Diana C. Robertson

Research Collection Lee Kong Chian School Of Business

Research linking marketing to financial performance has predominantly focused on how marketing assets and actions add value. The authors argue that it is equally important to understand how marketing decisions can reduce firm value. Prior research has indicated that negative events vary greatly in their indirect costs to the firm. On the basis of established theory and in-depth interviews with practitioners, the authors identify a set of factors that can explain the heterogeneity in the magnitude of indirect costs associated with negative marketing-related events. Specifically, they address how the regulatory exposure of deceptive marketing, which carries no direct cost to …

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Arresting The Saboteurs Of Strategic Change, Knowledge@Smu Oct 2009

Arresting The Saboteurs Of Strategic Change, Knowledge@Smu

Knowledge@SMU

What might ‘rotting’ tomatoes, dirty bus station toilets and an airport catastrophe have in common? They illustrate how organisational strategy, when badly implemented, can lead to disastrous results. According to Robin Speculand, CEO of Bridges Business Consultancy, most leaders spend an extraordinary amount of time and effort in formulating their strategies, yet they overlook many of the critical aspects that could determine a successful implementation of strategic change.

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Differential Reliance On Feelings In The Present Vs. The Future (Or Past): Affect As A Decision Making System Of The Present, Hanwen Hannah Chang, Michel Tuan Pham Oct 2009

Differential Reliance On Feelings In The Present Vs. The Future (Or Past): Affect As A Decision Making System Of The Present, Hanwen Hannah Chang, Michel Tuan Pham

Research Collection Lee Kong Chian School Of Business

We posit that compared to the cognitive system, the affective system of judgment and decision making is relatively more engaged in the present. Specifically, we hypothesize that even if their accessibility is held constant, affective feelings are weighted more heavily in consumer judgments and decisions set in the present than in equivalent judgments and decisions set in the future or in the past. Consistent with this proposition, results from six experiments show that (a) compared to a more distant future, a nearer future increases consumers’ relative preferences for options that are superior in terms of integral affect over options that …

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Distance Metric Learning From Uncertain Side Information With Application To Automated Photo Tagging, Lei Wu, Steven C. H. Hoi, Rong Jin, Jianke Zhu, Nenghai Yu Oct 2009

Distance Metric Learning From Uncertain Side Information With Application To Automated Photo Tagging, Lei Wu, Steven C. H. Hoi, Rong Jin, Jianke Zhu, Nenghai Yu

Research Collection School Of Computing and Information Systems

Automated photo tagging is essential to make massive unlabeled photos searchable by text search engines. Conventional image annotation approaches, though working reasonably well on small testbeds, are either computationally expensive or inaccurate when dealing with large-scale photo tagging. Recently, with the popularity of social networking websites, we observe a massive number of user-tagged images, referred to as "social images", that are available on the web. Unlike traditional web images, social images often contain tags and other user-generated content, which offer a new opportunity to resolve some long-standing challenges in multimedia. In this work, we aim to address the challenge of …

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Unsupervised Face Alignment By Robust Nonrigid Mapping, Jianke Zhu, Luc Van Gool, Steven C. H. Hoi Oct 2009

Unsupervised Face Alignment By Robust Nonrigid Mapping, Jianke Zhu, Luc Van Gool, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

We propose a novel approach to unsupervised facial image alignment. Differently from previous approaches, that are confined to affine transformations on either the entire face or separate patches, we extract a nonrigid mapping between facial images. Based on a regularized face model, we frame unsupervised face alignment into the Lucas-Kanade image registration approach. We propose a robust optimization scheme to handle appearance variations. The method is fully automatic and can cope with pose variations and expressions, all in an unsupervised manner. Experiments on a large set of images showed that the approach is effective.

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The Tricky Business Of Copying, Stealing And Protecting, Knowledge@Smu Oct 2009

The Tricky Business Of Copying, Stealing And Protecting, Knowledge@Smu

Knowledge@SMU

People click “yes” and “agree” on pop-up windows on their computer screens without much thought and without really knowing what they are agreeing to. But does the act of clicking bind a person, contractually? Terms and conditions presented on electronic devices have been known to be lengthy and dreary, thereby unappealing to the masses. Most people do not have the patience to read the entire list of items, so they choose, instead, to turn in their rights altogether – blindly. Why have people become indifferent and what are the implications for businesses? Andrea Matwyshyn, a speaker at the Wharton-SMU Research …

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Culture As Common Sense: Perceived Consensus Versus Personal Beliefs As Mechanisms Of Cultural Influence, Xi Zou, Kim-Pong Tam, Michael W. Morris, Sau-Lai Lee, Ivy Yee-Man Lau, Chi-Yue Chiu Oct 2009

Culture As Common Sense: Perceived Consensus Versus Personal Beliefs As Mechanisms Of Cultural Influence, Xi Zou, Kim-Pong Tam, Michael W. Morris, Sau-Lai Lee, Ivy Yee-Man Lau, Chi-Yue Chiu

Research Collection School of Social Sciences

The authors propose that culture affects people through their perceptions of what is consensually believed. Whereas past research has examined whether cultural differences in social judgment are mediated by differences in individuals’ personal values and beliefs, this article investigates whether they are mediated by differences in individuals’ perceptions of the views of people around them. The authors propose that individuals who perceive that traditional views are culturally consensual (e.g., Chinese participants who believe that most of their fellows hold collectivistic values) will themselves behave and think in culturally typical ways. Four studies of previously well-established cultural differences found that cultural …

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Analyzing And Forecasting Business Cycles In A Small Open Economy: A Dynamic Factor Model For Singapore, Hwee Kwan Chow, Keen Meng Choy Oct 2009

Analyzing And Forecasting Business Cycles In A Small Open Economy: A Dynamic Factor Model For Singapore, Hwee Kwan Chow, Keen Meng Choy

Research Collection School Of Economics

A dynamic factor model is applied to a large panel dataset of Singapore’s macroeconomic variables and global economic indicators with the initial objective of analysing business cycles in a small open economy. The empirical results suggest that four common factors – which can broadly be interpreted as world, regional, electronics and domestic economic cycles – capture a large proportion of the co-variation in the quarterly time series. The estimated factor model also explains well the observed fluctuations in real economic activity and price inflation, leading us to use it in forecasting Singapore’s business cycles. We find that the forecasts generated …

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Scalable Detection Of Partial Near-Duplicate Videos By Visual-Temporal Consistency, Hung-Khoon Tan, Chong-Wah Ngo, Richang Hong, Tat-Seng Chua Oct 2009

Scalable Detection Of Partial Near-Duplicate Videos By Visual-Temporal Consistency, Hung-Khoon Tan, Chong-Wah Ngo, Richang Hong, Tat-Seng Chua

Research Collection School Of Computing and Information Systems

Following the exponential growth of social media, there now exist huge repositories of videos online. Among the huge volumes of videos, there exist large numbers of near-duplicate videos. Most existing techniques either focus on the fast retrieval of full copies or near-duplicates, or consider localization in a heuristic manner. This paper considers the scalable detection and localization of partial near-duplicate videos by jointly considering visual similarity and temporal consistency. Temporal constraints are embedded into a network structure as directed edges. Through the structure, partial alignment is novelly converted into a network flow problem where highly efficient solutions exist. To precisely …

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Innovative Knowledge Assets And Economic Performance: The Asymmetric Roles Of Incentives And Monitoring, Jinyu He, Heli Wang Oct 2009

Innovative Knowledge Assets And Economic Performance: The Asymmetric Roles Of Incentives And Monitoring, Jinyu He, Heli Wang

Research Collection Lee Kong Chian School Of Business

We posit that a firm's resource configuration constitutes a critical context for various corporate governance mechanisms. Although innovative knowledge assets are generally a key determinant of a firm's economic performance, they also lead to greater information asymmetry among managers and owners and to the need to grant managers more discretion in making resource deployment decisions. This weakens the role of monitoring but increases the effectiveness of incentive mechanisms. Therefore, we hypothesize asymmetric moderating effects of monitoring- and incentive-based governance mechanisms on the relationship between innovative knowledge assets and economic performance. Our empirical analyses provide support for the key arguments.

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A Service Choice Model For Optimizing Taxi Service Delivery, Shih-Fen Cheng, Xin Qu Oct 2009

A Service Choice Model For Optimizing Taxi Service Delivery, Shih-Fen Cheng, Xin Qu

Research Collection School Of Computing and Information Systems

Taxi service has undergone radical revamp in recent years. In particular, significant investments in communication system and GPS devices have improved quality of taxi services through better dispatches. In this paper, we propose to leverage on such infrastructure and build a service choice model that helps individual drivers in deciding whether to serve a specific taxi stand or not. We demonstrate the value of our model by applying it to a real-world scenario. We also highlight interesting new potential approaches that could significantly improve the quality of taxi services.

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Presidents, Parties, And Policy Competition, Nina Wiesehomeier, Kenneth Benoit Oct 2009

Presidents, Parties, And Policy Competition, Nina Wiesehomeier, Kenneth Benoit

Research Collection School of Social Sciences

Presidential systems present a unique possibility for spatial competition between elected political agents, since presidents may represent different policy positions than the parties to which they belong. Previous research, however, has lacked a firm empirical basis on which to measure these differences. We remedy this situation, providing independent estimates of positions and saliencies for presidents and parties on multiple policy dimensions in 18 Latin American countries, from original expert survey data. Our results offer strong evidence that positioning on nearly all political issues neatly reduces to a single dimension of left-right contestation. Furthermore, contrasting differences between the positioning of presidents …

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Beyond Elitism: Community Ideal For A Modern East Asia, Sor-Hoon Tan Oct 2009

Beyond Elitism: Community Ideal For A Modern East Asia, Sor-Hoon Tan

Research Collection School of Social Sciences

It is often remarked that East Asian polities have been hierarchical and the "elite" category continues to figure prominently in works on Chinese society and politics. Many scholars believe that hierarchy and elitism are deeply rooted in Confucianism, which served as the state orthodoxy in imperial China and provided the "psycho-cultural construct" of the way of life in other East Asian cultural communities as well. It is therefore not surprising that some should believe that if modern Confucian societies are to be democratic at all, elitism must be reconciled with democracy. In contrast, elitism is commonly a pejorative term in …

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Mining Globally Distributed Frequent Subgraphs In A Single Labeled Graph, Xing Jiang, Hui Xiong, Chen Wang, Ah-Hwee Tan Oct 2009

Mining Globally Distributed Frequent Subgraphs In A Single Labeled Graph, Xing Jiang, Hui Xiong, Chen Wang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Recent years have observed increasing efforts on graph mining and many algorithms have been developed for this purpose. However, most of the existing algorithms are designed for discovering frequent subgraphs in a set of labeled graphs only. Also, the few algorithms that find frequent subgraphs in a single labeled graph typically identify subgraphs appearing regionally in the input graph. In contrast, for real-world applications, it is commonly required that the identified frequent subgraphs in a single labeled graph should also be globally distributed. This paper thus fills this crucial void by proposing a new measure, termed G-Measure, to find globally …

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Streaming 3d Meshes Using Spectral Geometry Images, Ying He, Boon Seng Chew, Dayong Wang, Steven C. H. Hoi, Lap Pui Chau Oct 2009

Streaming 3d Meshes Using Spectral Geometry Images, Ying He, Boon Seng Chew, Dayong Wang, Steven C. H. Hoi, Lap Pui Chau

Research Collection School Of Computing and Information Systems

The transmission of 3D models in the form of Geometry Images (GI) is an emerging and appealing concept due to the reduction in complexity from R3 to image space and wide availability of mature image processing tools and standards. However, geometry images often suffer from the artifacts and error during compression and transmission. Thus, there is a need to address the artifact reduction, error resilience and protection of such data information during the transmission across an error prone network. In this paper, we introduce a new concept, called Spectral Geometry Images (SGI), which naturally combines the powerful spectral analysis with …

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Analysis Of Tradeoffs Between Buffer And Qos Requirements In Wireless Networks, Raphael Rom, Hwee-Pink Tan Oct 2009

Analysis Of Tradeoffs Between Buffer And Qos Requirements In Wireless Networks, Raphael Rom, Hwee-Pink Tan

Research Collection School Of Computing and Information Systems

In this paper, we consider the scheduling problem where data packets from K input-flows need to be delivered to K corresponding wireless receivers over a heterogeneous wireless channel. Our objective is to design a wireless scheduler that achieves good throughput and fairness performance while minimizing the buffer requirement at each wireless receiver. This is a challenging problem due to the unique characteristics of the wireless channel. We propose a novel idea of exploiting both the long-term and short-term error behavior of the wireless channel in the scheduler design. In addition to typical first-order Quality of Service (QoS) metrics such as …

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A Study Of Content Authentication In Proxy-Enabled Multimedia Delivery Systems: Model, Techniques, And Applications, Robert H. Deng, Yanjiang Yang Oct 2009

A Study Of Content Authentication In Proxy-Enabled Multimedia Delivery Systems: Model, Techniques, And Applications, Robert H. Deng, Yanjiang Yang

Research Collection School Of Computing and Information Systems

Compared with the direct server-user approach, the server-proxy-user architecture for multimedia delivery promises significantly improved system scalability. The introduction of the intermediary transcoding proxies between content servers and end users in this architecture, however, brings unprecedented challenges to content security. In this article, we present a systematic study on the end-to-end content authentication problem in the server-proxy-user context, where intermediary proxies transcode multimedia content dynamically. We present a formal model for the authentication problem, propose a concrete construction for authenticating generic data modality and formally prove its security. We then apply the generic construction to authenticating specific multimedia formats, for …

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