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Aggregate Nearest Neighbor Queries In Spatial Databases, Dimitris Papadias, Yufei Tao, Kyriakos Mouratidis, Chun Kit Hui Jun 2005

Aggregate Nearest Neighbor Queries In Spatial Databases, Dimitris Papadias, Yufei Tao, Kyriakos Mouratidis, Chun Kit Hui

Research Collection School Of Computing and Information Systems

Given two spatial datasets P (e.g., facilities) and Q (queries), an aggregate nearest neighbor (ANN) query retrieves the point(s) of P with the smallest aggregate distance(s) to points in Q. Assuming, for example, n users at locations q1,...qn, an ANN query outputs the facility p belongs to P that minimizes the sum of distances |pqi| for 1 is less than or equal to i is less than or equal to n that the users have to travel in order to meet there. Similarly, another ANN query may report the point p belongs to P that minimizes the maximum distance that …


Dsi: A Fully Distributed Spatial Index For Wireless Data Broadcast, Wang-Chien Lee, Baihua Zheng Jun 2005

Dsi: A Fully Distributed Spatial Index For Wireless Data Broadcast, Wang-Chien Lee, Baihua Zheng

Research Collection School Of Computing and Information Systems

Recent announcement of the MSN Direct Service has demonstrated the feasibility and industrial interest in utilizing wireless broadcast for pervasive information services. To support location-based services in wireless data broadcast systems, a distributed spatial index (called DSI) is proposed in this paper. DSI is highly efficient because it has a linear yet fully distributed structure that facilitates multiple search paths to be naturally mixed together by sharing links. Moreover, DSI is very resilient in error-prone wireless communication environments. Search algorithms for two classical location-based queries, window queries and kNN queries, based on DSI are presented. Performance evaluation of DSI shows …


Exporting Expertise: Singapore's Gambit In Vietnam Revisited, Caroline Yeoh, Ai Lin Leong, Xun Cai Jun 2005

Exporting Expertise: Singapore's Gambit In Vietnam Revisited, Caroline Yeoh, Ai Lin Leong, Xun Cai

Research Collection Lee Kong Chian School Of Business

Infrastructure can be unreliable and administration subject to corruption in Asia’s rapidly emerging economies. This context presented Singapore with unique opportunities to export its expertise to locations where these attributes are less certain, through the provision of superior infrastructure, the ability to negotiate investment concessions and, where existing, through the links to influential business groups in the investment location. This strategic initiative is further premised on the perception that Singapore’s positive reputation with multinationals, as well as ‘guanxi’, or connections, with Asian business networks, will give the industrial-township projects a marketing advantage. Their progress is a litmus test of Singapore’s …


Diffusion Of Art: An Investigation Of The Evolution Of Modern Indian Art, Srinivas K. Reddy, Mayukh Dass, Umesh Gaur Jun 2005

Diffusion Of Art: An Investigation Of The Evolution Of Modern Indian Art, Srinivas K. Reddy, Mayukh Dass, Umesh Gaur

Research Collection Lee Kong Chian School Of Business

No abstract provided.


Jackknifing Bond Option Prices, Peter C. B. Phillips, Jun Yu Jun 2005

Jackknifing Bond Option Prices, Peter C. B. Phillips, Jun Yu

Research Collection School Of Economics

Prices of interest rate derivative securities depend crucially on the mean reversion parameters of the underlying diffusions. These parameters are subject to estimation bias when standard methods are used. The estimation bias can be substantial even in very large samples and much more serious than the discretization bias, and it translates into a bias in pricing bond options and other derivative securities that is important in practical work. This article proposes a very general and computationally inexpensive method of bias reduction that is based on Quenouille's (1956; Biometrika, 43, 353-360) jackknife. We show how the method can be applied directly …


Breaking Public Key Cryptosystems On Tamper Resistant Devices In The Presence Of Transient Faults, Feng Bao, Robert H. Deng, Y. Han, A. Jeng, Arcot Desai Narasimhalu, T. Ngair Jun 2005

Breaking Public Key Cryptosystems On Tamper Resistant Devices In The Presence Of Transient Faults, Feng Bao, Robert H. Deng, Y. Han, A. Jeng, Arcot Desai Narasimhalu, T. Ngair

Research Collection School Of Computing and Information Systems

In this paper we present a method of attacking public-key cryptosystems (PKCs) on tamper resistant devices. The attack makes use of transient faults and seems applicable to many types of PKCs. In particular, we show how to attack the RSA, the E1Gamal signature scheme, the Schnorr signature scheme, and the DSA. We also present some possible methods to counter the attack.


The Operational Validity Of A Video-Based Situational Judgment Test For Medical College Admissions: Illustrating The Importance Of Matching Predictor And Criterion Construct Domains, Filip Lievens, Tine Buyse, Paul R. Sackett May 2005

The Operational Validity Of A Video-Based Situational Judgment Test For Medical College Admissions: Illustrating The Importance Of Matching Predictor And Criterion Construct Domains, Filip Lievens, Tine Buyse, Paul R. Sackett

Research Collection Lee Kong Chian School Of Business

This study is part of a trend of examining noncognitive predictors, for example, a situational judgment test (SJT), as supplements to cognitive predictors for making college admission decisions. The authors examined criterion data over multiple academic years and universities. The criterion domain was broadly conceptualized, including both cognitive and interpersonal domains. The sample consisted of 7,197 candidates of the Medical and Dental Studies Admission Exam in Belgium. Results confirmed the importance of cognitive predictors. A video-based SJT was differentially valid for predicting overall grade point average for different curricula. The SJT showed incremental validity over cognitively oriented measures for curricula …


Firm Ownership Structure And Intellectual Capital Disclosures, Stephen Firer, S. M. Williamson May 2005

Firm Ownership Structure And Intellectual Capital Disclosures, Stephen Firer, S. M. Williamson

Research Collection School Of Accountancy

The primary purpose of this study is to investigate the association between three ownership structure characteristics and voluntary intellectual capital (IC) disclosure practices. Data for this study is hand collected from the 2000 annual reports of 390 Singapore publicly traded firms. Empirical results indicate Singapore publicly traded firms more closely owned were less likely to voluntarily disclose IC related information than were those where executive directors had smaller holdings in the entity. Finally, findings indicate government linked corporations (GLCs) will likely make more voluntary IC disclosures than non-GLCs. Overall, this study makes several unique contributions to the literature. First, the …


What Makes Knowledge Sharing In Organizations Tick? An Empirical Study, Yue Wah Chay, Thomas Menkhoff, Benjamin Loh, Hans-Dieter Evers May 2005

What Makes Knowledge Sharing In Organizations Tick? An Empirical Study, Yue Wah Chay, Thomas Menkhoff, Benjamin Loh, Hans-Dieter Evers

Research Collection Lee Kong Chian School Of Business

No abstract provided.


Mining Mobile Group Patterns: A Trajectory-Based Approach, San-Yih Hwang, Ying-Han Liu, Jeng-Kuen Chiu, Ee Peng Lim May 2005

Mining Mobile Group Patterns: A Trajectory-Based Approach, San-Yih Hwang, Ying-Han Liu, Jeng-Kuen Chiu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In this paper, we present a group pattern mining approach to derive the grouping information of mobile device users based on a trajectory model. Group patterns of users are determined by distance threshold and minimum time duration. A trajectory model of user movement is adopted to save storage space and to cope with untracked or disconnected location data. To discover group patterns, we propose ATGP algorithm and TVG-growth that are derived from the Apriori and VG-growth algorithms respectively.


Synthesizing E-Government Stage Models – A Meta-Synthesis Based On Meta-Ethnography Approach, Keng Siau, Y. Long May 2005

Synthesizing E-Government Stage Models – A Meta-Synthesis Based On Meta-Ethnography Approach, Keng Siau, Y. Long

Research Collection School Of Computing and Information Systems

The growing interest in e-government raises the question of stages in e-government development. A few stage models for e-government have been proposed. Without a common e-government stage model, different research in e-government may be based on different stage models. This presents a difficulty in comparing and understanding different research results. In this research, we synthesize the existing e-government stage models so that there is a common frame of reference for researchers and practitioners in the area.


Leveraging Global Resources: A Distributed Process Maturity Framework For Software Product Development, Narayan Ramasubbu, M. S. Krishnan, Prasad Kompalli May 2005

Leveraging Global Resources: A Distributed Process Maturity Framework For Software Product Development, Narayan Ramasubbu, M. S. Krishnan, Prasad Kompalli

Research Collection School Of Computing and Information Systems

Distributed software development is pervasive in the software industry today as companies vie to leverage global resources. However, popular quality and process frameworks don?t specifically address the key processes needed for managing distributed software development. This practitioner-oriented, evolutionary process maturity framework for globally distributed software development features 24 new key process areas essential for managing distributed software product development and for continuously improving product management capabilities. An assessment survey helps practitioners implement the framework. In this article, the authors detail the framework and assessment survey, as well as report their experiences implementing the framework at a leading global firm. The …


'Treaties', 'Agreements', 'Contracts' And 'Commitments' - What's In A Name? The Legal Force And Meaning Of Different Forms Of Agreement Making, David Llewelyn, Maureen Tehan May 2005

'Treaties', 'Agreements', 'Contracts' And 'Commitments' - What's In A Name? The Legal Force And Meaning Of Different Forms Of Agreement Making, David Llewelyn, Maureen Tehan

Research Collection Yong Pung How School Of Law

The multi-dimensional nature of treaty and agreement making has assumed a central focus in the conduct of relations between Indigenous peoples and settlers in Australia and elsewhere. Whether as a means of resolving disputes, delivering government programmes, or establishing common understandings, agreement making, however defined and named, has become the key tool for engagement between Indigenous and non-Indigenous Australians. Agreements come in all shapes and sizes ranging from registered Indigenous Land Use Agreements (ILUA) to Statements of Commitment, Memorandums of Understanding and Regional Agreements. In other jurisdictions these may be called 'treaties'. This paper examines the plethora of agreements in …


Non-Market Leadership Experience And Labor Market Success: Evidence From Military Rank, Myoung-Jae Lee, Chun Seng Yip May 2005

Non-Market Leadership Experience And Labor Market Success: Evidence From Military Rank, Myoung-Jae Lee, Chun Seng Yip

Research Collection School Of Economics

There has been much recent interest in the effects of pre and non-market skills on future labor market outcomes. This paper examines one such effect: the effect on future wages of military leadership experience among Vietnam generation American men. We study rank, not just veteran status. We argue that rank is a good measure of pre-market leadership skills because of the clear military hierarchy and the primarily youth experience of Vietnam service. Two sources of selection bias are accounted for: non-random military entry and eventual rank attained. We apply a modified 2-stage parametric sample selection method. The rank premia on …


Dynamically-Optimized Context In Recommender Systems, Ghim-Eng Yap, Ah-Hwee Tan, Hwee-Hwa Pang May 2005

Dynamically-Optimized Context In Recommender Systems, Ghim-Eng Yap, Ah-Hwee Tan, Hwee-Hwa Pang

Research Collection School Of Computing and Information Systems

Traditional approaches to recommender systems have not taken into account situational information when making recommendations, and this seriously limits the relevance of the results. This paper advocates context-awareness as a promising approach to enhance the performance of recommenders, and introduces a mechanism to realize this approach. We present a framework that separates the contextual concerns from the actual recommendation module, so that contexts can be readily shared across applications. More importantly, we devise a learning algorithm to dynamically identify the optimal set of contexts for a specific recommendation task and user. An extensive series of experiments has validated that our …


Synthesizing E-Government Stage Models – A Meta-Synthesis Based On Meta-Ethnography Approach, Keng Siau, Y. Long May 2005

Synthesizing E-Government Stage Models – A Meta-Synthesis Based On Meta-Ethnography Approach, Keng Siau, Y. Long

Research Collection School Of Computing and Information Systems

The growing interest in e-government raises the question of stages in e-government development. A few stage models for e-government have been proposed. Without a common e-government stage model, different research in e-government may be based on different stage models. This presents a difficulty in comparing and understanding different research results. In this research, we synthesize the existing e-government stage models so that there is a common frame of reference for researchers and practitioners in the area.


Event-Driven Document Selection For Terrorism, Zhen Sun, Ee Peng Lim, Kuiyu Chang, Teng-Kwee Ong, Rohan Kumar Gunaratna May 2005

Event-Driven Document Selection For Terrorism, Zhen Sun, Ee Peng Lim, Kuiyu Chang, Teng-Kwee Ong, Rohan Kumar Gunaratna

Research Collection School Of Computing and Information Systems

In this paper, we examine the task of extracting information about terrorism related events hidden in a large document collection. The task assumes that a terrorism related event can be described by a set of entity and relation instances. To reduce the amount of time and efforts in extracting these event related instances, one should ideally perform the task on the relevant documents only. We have therefore proposed some document selection strategies based on information extraction (IE) patterns. Each strategy attempts to select one document at a time such that the gain of event related instance information is maximized. Our …


Information Dissemination Via Wireless Broadcast, Baihua Zheng, Dik Lun Lee May 2005

Information Dissemination Via Wireless Broadcast, Baihua Zheng, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Unrestricted mobility adds a new dimension to data access methodology--- one that must be addressed before true ubiquity can be realized.


Dynamically Optimized Context In Recommender Systems, Ghim-Eng Yap, Ah-Hwee Tan, Hwee Hwa Pang May 2005

Dynamically Optimized Context In Recommender Systems, Ghim-Eng Yap, Ah-Hwee Tan, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

Traditional approaches to recommender systems have not taken into account situational information when making recommendations, and this seriously limits the relevance of the results. This paper advocates context-awareness as a promising approach to enhance the performance of recommenders, and introduces a mechanism to realize this approach. We present a framework that separates the contextual concerns from the actual recommendation module, so that contexts can be readily shared across applications. More importantly, we devise a learning algorithm to dynamically identify the optimal set of contexts for a specific recommendation task and user. An extensive series of experiments has validated that our …


Protecting Group Dynamic Information In Large Scale Multicast Groups, Yongdong Wu, Tieyan Li, Robert H. Deng May 2005

Protecting Group Dynamic Information In Large Scale Multicast Groups, Yongdong Wu, Tieyan Li, Robert H. Deng

Research Collection School Of Computing and Information Systems

Existing key management schemes can secure group communication efficiently, but are failed on protecting the Group Dynamic Information (GDI) that may undermine group privacy. Recently, Sun et al. proposed a scheme to hide the GDI with batch updating and phantom members inserting so that an adversary is not able to estimate the number of group members. In this paper, we first point out that their scheme is only applicable in departure-only group communication instead of the common conference groups. Secondly, we introduce our method of estimating the group size at a higher confidence level given a prior departure probability. Further, …


A New Architecture For User Authentication And Key Exchange Using Password For Federated Enterprises, Yanjiang Yang, Feng Bao, Robert H. Deng May 2005

A New Architecture For User Authentication And Key Exchange Using Password For Federated Enterprises, Yanjiang Yang, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

The rapid rise of federated enterprises entails a new way of trust management by the fact that an enterprise can account for partial trust of its affiliating organizations. On the other hand, password has historically been used as a main means for user authentication because of operational simplicity. We are thus motivated to explore the use of short password for user authentication and key exchange in the context of federated enterprises. Exploiting the special structure of a federated enterprise, our proposed new architecture comprises an external server managed by each affiliating organization and a central server managed by the enterprise …


Secure Human Communications Based On Biometrics Signals, Yongdong Wu, Feng Bao, Robert H. Deng May 2005

Secure Human Communications Based On Biometrics Signals, Yongdong Wu, Feng Bao, Robert H. Deng

Research Collection School Of Computing and Information Systems

User authentication is the first and probably the most challenging step in achieving secure person-to-person communications. Most of the existing authentication schemes require communicating parties either share a secret/password or know each other's public key. In this paper we suggest a novel user authentication scheme that is easy to use and overcomes the requirements of sharing password or public keys. Our scheme allows two human users to perform mutual authentication and have secure communications over an open channel by exchanging biometrics signals (e. g., voice or video signals). In addition to user authentication, our scheme establishes a secret session key …


Tosa: A Near-Optimal Scheduling Algorithm For Multi-Channel Data Broadcast, Baihua Zheng, Xia Xu, Xing Jin, Dik Lun Lee May 2005

Tosa: A Near-Optimal Scheduling Algorithm For Multi-Channel Data Broadcast, Baihua Zheng, Xia Xu, Xing Jin, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Wireless broadcast is very suitable for delivering information to a large user population. In this paper, we concentrate on data allocation methods for multiple broadcast channels. To the best of our knowledge, this is the first allocation model that takes into the consideration of items' access frequencies, items' lengths. and bandwidth of different channels. We first derive the optimal average expected delay for multiple channels for the general case where data access frequencies, data sizes, and channel bandwidths can all be non-uniform. Second, we develop TOSA, a multi-channel allocation method that does not assume a uniform broadcast schedule for data …


Minimum Energy Reliable Paths Using Unreliable Wireless Links, Qunfeng Dong, Suman Banerjee, Micah Adler, Archan Misra May 2005

Minimum Energy Reliable Paths Using Unreliable Wireless Links, Qunfeng Dong, Suman Banerjee, Micah Adler, Archan Misra

Research Collection School Of Computing and Information Systems

We address the problem of energy-efficient reliable wireless communication in the presence of unreliable or lossy wireless link layers in multi-hop wireless networks. Prior work [1] has provided an optimal energy efficient solution to this problem for the case where link layers implement perfect reliability. However, a more common scenario --- a link layer that is not perfectly reliable, was left as an open problem. In this paper we first present two centralized algorithms, BAMER and GAMER, that optimally solve the minimum energy reliable communication problem in presence of unreliable links. Subsequently we present a distributed algorithm, DAMER, that approximates …


Live Data Views: Programming Pervasive Applications That Use “Timely” And “Dynamic” Data, Jay Black, Paul Castro, Archan Misra, Jerome White May 2005

Live Data Views: Programming Pervasive Applications That Use “Timely” And “Dynamic” Data, Jay Black, Paul Castro, Archan Misra, Jerome White

Research Collection School Of Computing and Information Systems

In the absence of generic programming abstractions for dynamic data in most enterprise programming environments, individual applications treat data streams as a special case requiring custom programming. With the growing number of live data sources such as RSS feeds, messaging and presence servers, multimedia streams, and sensor data. a general-purpose client-server programming model is needed to easily incorporate live data into applications. In this paper, we present Live Data Views, a programming abstraction that represents live data as a time-windowed view over a set of data streams. Live Data Views allow applications to create and retrieve stateful abstractions of dynamic …


The Impact Of Ownership Structure On Wage Intensity In Japanese Corporations, Toru Yoshikawa, Phillip H. Phan, Parthiban David Apr 2005

The Impact Of Ownership Structure On Wage Intensity In Japanese Corporations, Toru Yoshikawa, Phillip H. Phan, Parthiban David

Research Collection Lee Kong Chian School Of Business

The authors studied the effect of ownership structure on human capital investments as indicated by wage intensity, defined as the ratio of expenditure on employee wages to sales, in a sample of 996 Japanese manufacturing firms during their economic recession of 1998-2002. They found that domestic shareholders, with interests beyond financial considerations, enhance wage intensity, especially when performance is low, and thereby safeguard human capital investments. Foreign shareholders with sole interest in financial returns have an opposite effect; they reduce wage intensity when firm performance is low.


Spatial Orientation Strategies In Morris-Type Virtual Water Task For Humans, Janos Kallai, Tamas Makany, Kazmer Karadi, William J. Jacobs Apr 2005

Spatial Orientation Strategies In Morris-Type Virtual Water Task For Humans, Janos Kallai, Tamas Makany, Kazmer Karadi, William J. Jacobs

Research Collection Lee Kong Chian School Of Business

The present study characterized frequent motion patterns (search strategies) that occurred during spatial navigation in a virtual maze. The research focused on identifying and characterizing some search strategies, the temporal progression of strategy-use, and their role in spatial performance. Participants were 112 undergraduate students (42 males and 70 females). We identified three search strategies that predicted spatial performance. Enfilading refers to an approach-withdrawal pattern of active exploration near a target location. Thigmotaxis refers to a search strategy that involves continuous contact with the circular wall of the maze. Visual scan involves active visual exploration while the subject remains in a …


Ais Sighci Position Paper, Dennis Galletta, Ping Zhang, Fiona Fui-Hoon Nah Apr 2005

Ais Sighci Position Paper, Dennis Galletta, Ping Zhang, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

The upcoming ACM SIGCHI Development Consortium is aimed at meeting the needs of multidisciplinary professionals that must choose among a variety of professional associations and their events. The position of AIS' (Association for Information Systems) SIGHCI is that the main problem lies in the deep chasms that separate the literatures of the related disciplines, and the solution is to provide an umbrella organization that enables a more organized federation of disciplines, groups, and associations. Problems identified include differences in terminology, competition for scarce resources, differences in how publications in various outlets are valued, and confusion about where should be the …


Mining Social Network From Spatio-Temporal Events, Hady Wirawan Lauw, Ee Peng Lim, Teck Tim Tan, Hwee Hwa Pang Apr 2005

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 Apr 2005

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 …