Digital Commons Network^™

Mining Social Network From Spatio-Temporal Events, Hady Wirawan Lauw, Ee Peng Lim, Teck Tim Tan, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

Knowing patterns of relationship in a social network is very useful for law enforcement agencies to investigate collaborations among criminals, for businesses to exploit relationships to sell products, or for individuals who wish to network with others. After all, it is not just what you know, but also whom you know, that matters. However, finding out who is related to whom on a large scale is a complex problem. Asking every single individual would be impractical, given the huge number of individuals and the changing dynamics of relationships. Recent advancement in technology has allowed more data about activities of individuals …

Walverine: A Walrasian Trading Agent, Shih-Fen Cheng, Evan Leung, Kevin M. Lochner, Kevin O'Malley, Daniel M. Reeves, Julian L. Schvartzman, Michael P. Wellman

Research Collection School Of Computing and Information Systems

TAC-02 was the third in a series of Trading Agent Competition events fostering research in automating trading strategies by showcasing alternate approaches in an open-invitation market game. TAC presents a challenging travel-shopping scenario where agents must satisfy client preferences for complementary and substitutable goods by interacting through a variety of market types. Michigan's entry, Walverine, bases its decisions on a competitive (Walrasian) analysis of the TAC travel economy. Using this Walrasian model, we construct a decision-theoretic formulation of the optimal bidding problem, which Walverine solves in each round of bidding for each good. Walverine's optimal bidding approach, as well as …

Proactive Caching For Spatial Queries In Mobile Environments, Haibo Hu, Jianliang Xu, Wing Sing Wong, Baihua Zheng, Dik Lun Lee, Wang-Chien Lee

Research Collection School Of Computing and Information Systems

Semantic caching enables mobile clients to answer spatial queries locally by storing the query descriptions together with the results. However, it supports only a limited number of query types, and sharing results among these types is difficult. To address these issues, we propose a proactive caching model which caches the result objects as well as the index that supports these objects as the results. The cached index enables the objects to be reused for all common types of queries. We also propose an adaptive scheme to cache such an index, which further optimizes the query response time for the best …

Privacy And Ownership Preserving Of Outsourced Medical Data, Elisa Bertino, Beng Chin Ooi, Yanjiang Yang, Robert H. Deng

Research Collection School Of Computing and Information Systems

The demand for the secondary use of medical data is increasing steadily to allow for the provision of better quality health care. Two important issues pertaining to this sharing of data have to be addressed: one is the privacy protection for individuals referred to in the data; the other is copyright protection over the data. In this paper, we present a unified framework that seamlessly combines techniques of binning and digital watermarking to attain the dual goals of privacy and copyright protection. Our binning method is built upon an earlier approach of generalization and suppression by allowing a broader concept …

Providing Efficient Certification Services Against Active Attacks In Ad Hoc Networks, Bo Zhu, Guilin Wang, Zhiguo Wan, Mohan S. Kankanhalli, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

Most of previous research work in key management can only resist passive attacks, such as dropping the certificate request, and are vulnerable under active attacks, such as returning a fake reply to the node requesting the certification service. In this paper, we propose two algorithms to address both security and efficiency issues of certification services in ad hoc networks. Both of the algorithms can resist active attacks. In addition, simulation results show that, compared to the previous works, our second algorithm is not only much faster in a friendly environment, but it also works well in a hostile environment in …

Sustainable External Debt Levels: Estimates For Selected Asian Countries, Roberto S. Mariano, Delano Villanueva

Research Collection School Of Economics

High ratios of external debt to GDP in selected Asian countries have contributed to the initiation, propagation, and severity of the financial and economic crises in recent years, reflecting runaway fiscal deficits and excessive foreign borrowing by the private sector. Applying the formal framework proposed by Villanueva (2003) to a selected group of Asian countries, the research estimates the external debt thresholds beyond which further debt accumulation will have negative effects on growth and will become unsustainable. The framework is an extension of the standard neoclassical growth model that incorporates global capital markets. ‘Sustainability’ is measured in terms of the …

The Performance Of Value And Growth Portfolios In East Asia Before The Asian Financial Crisis, David K. Ding, Jia-Leng Chua, Thomas A. Fetherston

Research Collection Lee Kong Chian School Of Business

We examine value and growth portfolios in seven East Asian countries just before the onslaught of the 1997 Asian Financial Crisis. The value premiums in these countries, except in Indonesia, Taiwan, and Thailand, are found to be mainly positive. After controlling for firm size, risk, liquidity, and growth potential, we find higher returns among value stocks with a small firm size and low growth potential in Hong Kong and Malaysia. In Japan and Singapore, higher returns are found in growth portfolios with a small firm size and low growth potential. Growth stocks in Taiwan with a small firm size, and …

Competing At The Frontier: The Changing Role Of Technology Policy In Singapore's Economic Strategy, Winston T. H. Koh, Poh Kam Wong

Research Collection School Of Economics

For an economy competing at the global frontier, an innovation-based growth strategy requires a well-developed technological infrastructure, a set of capabilities-focused technology policies, as well as an institutional environment that stimulates innovation and entrepreneurship. This paper examines the role played by science and technology policy in an economy's transition to an innovation-based growth strategy. We discuss the challenges governments face as they restructure economic institutions to deepen R&D capabilities and encourage technology creation. We review Singapore's experience in this regard and assess its ongoing efforts to remake itself to compete at the global frontier.

Bougainville Community Crime Trends: A Survey Of Crime In Arawa And Buka, Mark Findlay, Gerard Guthrie, Fiona Hukula, James Laki

Research Collection Yong Pung How School Of Law

The fundamental difference in the role of the state in the recent histories of Arawa and Buka is critical to understanding community attitudes to crime and policing. In Arawa, the state was entirely absent for over 10 years during the civil war and community-based agencies provided the sole source of authority and social control. In Buka, the state remained in control in difficult circumstances. The peace process was based around indigenous dispute resolution techniques and now a role for the state is being gradually reintroduced into post-conflict Bougainville, including of policing services to Arawa. The differences in the recent histories …

Corruption Across Countries And Regions: Some Consequences Of Local Osmosis, Raaj Sah

Research Collection School Of Economics

Large and persistent differences in corruption across comparable countries is a challenging research issue. Even more intriguing are such differences across regions within the same country, because the typically considered socioeconomic and governance characteristics are generally more similar across such regions than across different countries. This paper's principal theme is that individuals’ perceptions of their environments are influenced by the realities that they have faced in the past; these perceptions affect their current and future actions; which in turn influence the current and future realities. An articulation and analysis of these dynamics yields significant observations concerning individuals’ behavior and societal …

Some Patterns Of Market Shares Of Brands Within And Across Product Categories, Rajeev Kohli, Raaj Sah

Research Collection School Of Economics

This paper: (i) reports an empirical regularity in the market shares of brands; (ii) presents a theoretical framework for understanding the observed regularity; (iii) adduces additional empirical consequences of the framework, which are some counterintuitive relationships among market shares of brands across different product categories; and (iv) presents empirical evidence for these consequences, thus providing additional support for the theoretical framework. Our cross-sectional data on market shares consists of 1171 brands in 91 product categories of foods and sporting goods sold in the US. If we assign a lower rank to a brand with a higher market share, then the …

Do We Stand On Common Ground? A Threat Appraisal Model For Terror Alerts Issued By The Department Of Homeland Security, Augustine Pang, Yan Jin, Glen T. Cameron

Research Collection Lee Kong Chian School Of Business

Having developed a threat appraisal model to examine the fabric and faces of threat, and how it can becommunicated, the authors empirically test the model on an ongoing issue, the issuance of terror alerts bythe Department of Homeland Security (DHS), on how threat is appraised by DHS, and the conservativeand liberal audiences. Findings showed a shared view by the DHS and the conservative audiences whilethe liberal audiences thought otherwise. Though there appear to be consensus in threat communication,more internal consistency within DHS is needed to optimize its effectiveness.

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 …

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.

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 …

Scheduling Queries To Improve The Freshness Of A Website, Haifeng Liu, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

The World Wide Web is a new advertising medium that corporations use to increase their exposure to consumers. Very large websites whose content is derived from a source database need to maintain a freshness that reflects changes that are made to the base data. This issue is particularly significant for websites that present fast-changing information such as stock-exchange information and product information. In this article, we formally define and study the freshness of a website that is refreshed by a scheduled set of queries that fetch fresh data from the databases. We propose several online-scheduling algorithms and compare the performance …

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 …

Older Workers: Untapped Assets For Creating Value, Knowledge@Smu

Knowledge@SMU

The days when an executive could look forward to a leisurely retirement out on the golf course are over, thanks to a possible looming job shortage, a graying population, low savings rates and an insecure Social Security system. The impact of these factors on both workers and companies was the subject of the Symposium on Older Workers, co-sponsored recently by the AARP Global Aging Program along with Wharton's Center for Human Resources and Boettner Center for Pensions and Retirement Research. Speakers included AARP CEO William D. Novelli, Olivia Mitchell, executive director of Wharton's Pension Research Council, and Thomas Dowd, a …

Managing Learning Resources For Consecutive Product Generations, Lieven Demeester, Mei Qi

Research Collection Lee Kong Chian School Of Business

In this paper, we study how a firm should allocate its learning resources when it is concurrently producing two consecutive generations of one product. We define learning resources as scarce firm-specific resources that a firm allocates towards the improvement of the cost, quality or timeliness of its existing products and processes. We use empirically tested models for demand substitution and learning curves to formulate this problem, and we present our results as propositions with regard to the optimal time at which a firm should direct all its learning resources to the newer product generation, depending on the substitution rate of …

Introduction: China, Ltd, William A. Callahan

Research Collection School of Social Sciences

The study of Chinese nationalism is very popular--both in China and the West. This article introduces a special section of seven articles (four of which are in this issue) on 'The Limits of Chinese Nationalism', arguing that our understanding of nationalism in China is problematic. This special section aims to explore the limits of many of the statements about Chinese nationalism that have now become 'common sense': the rise of Chinese nationalism, nationalism filling an ideological vacuum, elites manipulating nationalism to gain legitimacy, and so on. Using critical IR theory this Introduction explores the concept of limits to argue that …

Transient Response Of Arrow Vcsels, Chyng Wen Tee, S. F. Yu, R. V. Penty, I. H. White

Research Collection Lee Kong Chian School Of Business

The transient response of antiresonant reflecting optical waveguide (ARROW) vertical-cavity surface-emitting lasers (VCSELs) is analyzed. It is found that under current modulation, the radiation loss of the transverse-leaky mode decreases during the state of the lasers but increases during the state. Numerical analysis shows that this variation in radiation loss is due to the carrier-induced refractive-index depression that arises from spatial-hole-burning of carrier concentration. It is noted that the increment in radiation loss during the state can be used to prevent net modal gain of the transverse-leaky mode from reacquiring threshold after turn-off. Hence, a new method to design ARROW, …

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 …

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.

Questioning Proximity: East Asian Tv Dramas In Indonesia, Charlotte Setijadi

Research Collection School of Social Sciences

The study of transnational cultural flows has been of continuing interest among media and communication researchers, with recent studies focusing on cultural flows within geographically and culturally adjacent nations. It is often suggested that the level of “cultural proximity” that exists determines the success of cultural exchange between countries regarded to possess similar cultural traits. This notion, that local audiences will have preference for cultural commodities from countries with which they share cultural ties in recognition of their own culture, has enjoyed much intellectual currency in recent times, especially in relation to analyses of regional media markets. The danger of …

Singapore Management University Report To Stakeholders 2005 - 2006, Singapore Management University

Report to Stakeholders

With the official opening of the city campus in January 2006, SMU marked a new chapter in the history of central Singapore and became an integral part of the area s continual cycle of renewal. Building on the legacy of venerable institutions in Bras Basah that formed the educational hub of yesteryear, our aim is to produce visionary leaders for tomorrow, imbued with a fine sense of ethics and social responsibility for the good of the community.

From its beginning, SMU has been a catalyst for the future development of higher education in Singapore. Two ways that we have done …

Residual Life Distributions From Component Degradation Signals: A Bayesian Approach, Nagi Gebraeel, Mark Lawley, Rong Li, Jennifer Ryan

Research Collection Lee Kong Chian School Of Business

No abstract provided.

Politico-Economic Factors Associated With Interest In Starting A Business: A Multi-Country Study, Thomas Begley, Wee Liang Tan, Herbert Schoch

Research Collection Lee Kong Chian School Of Business

Public health is a legal term of art referring specifically to delineated powers, duties, rights, and responsibilities. An emerging human rights conception of public health justifies government intervention. Intervention involves public officials taking appropriate measures including environmental regulations pursuant to specific legal authority, after balancing private rights and public interests, to protect the health of the public. This article is a critical analysis of the performance of the actors in maintaining environmental standards in India. Part II is a discussion on the source of environmental law in India. Part III discusses the performance of the legislature. Part IV evaluates the …

Intellectual Capital Performance And Cash-Based Incentive Payments: Impact Of Remuneration Committee And Corporate Governance Features, Jean-Luc Wolfgang Mitchell Van Der Zahn, Inderpal Singh, Alistair Brown

Research Collection School Of Accountancy

No abstract provided.

Linear Correlation Discovery In Databases: A Data Mining Approach, Cecil Chua, Roger Hsiang-Li Chiang, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Very little research in knowledge discovery has studied how to incorporate statistical methods to automate linear correlation discovery (LCD). We present an automatic LCD methodology that adopts statistical measurement functions to discover correlations from databases’ attributes. Our methodology automatically pairs attribute groups having potential linear correlations, measures the linear correlation of each pair of attribute groups, and confirms the discovered correlation. The methodology is evaluated in two sets of experiments. The results demonstrate the methodology’s ability to facilitate linear correlation discovery for databases with a large amount of data.

Ontology-Assisted Mining Of Rdf Documents, Tao Jiang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Resource description framework (RDF) is becoming a popular encoding language for describing and interchanging metadata of web resources. In this paper, we propose an Apriori-based algorithm for mining association rules (AR) from RDF documents. We treat relations (RDF statements) as items in traditional AR mining to mine associations among relations. The algorithm further makes use of a domain ontology to provide generalization of relations. To obtain compact rule sets, we present a generalized pruning method for removing uninteresting rules. We illustrate a potential usage of AR mining on RDF documents for detecting patterns of terrorist activities. Experiments conducted based on …