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Hybridizing Discrete- And Continuous-Time Models For Batch Sizing And Scheduling Problems, Siqun Wang, Monique Guignard Jan 2006

Hybridizing Discrete- And Continuous-Time Models For Batch Sizing And Scheduling Problems, Siqun Wang, Monique Guignard

Research Collection Lee Kong Chian School Of Business

This paper proposes a new hybrid technique called partial parameter uniformization (hereafter PPU). The technique simplifies problems by ignoring the different values that certain problem parameters can take, which may facilitate the solution of some hard combinatorial optimization problems. PPU is applied to complex batch sizing and scheduling problems. Some information can be obtained from a discrete-time model in which job durations have been made uniform. This information is then exploited by a more detailed continuous-time model to generate feasible solutions and further improve these solutions. Good, or optimal solutions to the Westenberger and Kallrath Benchmark problems have been obtained …

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Asymmetry Of Processing Trade In China : Theory And Empirics, Zhaopeng Xing Jan 2006

Asymmetry Of Processing Trade In China : Theory And Empirics, Zhaopeng Xing

Dissertations and Theses Collection (Open Access)

This paper studies decision of whether outsourcing or localization in China. Both strategies can enjoy low wage advantage. But outsourcing induces processing trade, while localization, which has additional localization cost can turn processing trade of some goods to ordinary trade. The asymmetric effect lies on that once localized, it is hard to return to outsourcing due to competition or fixed expenditures involved. If wage difference larger, it is more preferable to localized. Therefore, we can expect asymmetric effect of processing trade due to movement of relative wage difference, which was proved by econometrics on recent data by cointegrating analysis within …

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The Impact Of Financial Market And Resale Market On Firm Strategies, Zhiling Guo, Andrew B. Whinston Jan 2006

The Impact Of Financial Market And Resale Market On Firm Strategies, Zhiling Guo, Andrew B. Whinston

Research Collection School Of Computing and Information Systems

The ever-increasing use of information technology (IT) in business transactions greatly expands firms? exposure to different electronic markets. This paper provides a framework to understand how firms can leverage different strategies across external financial markets and an internal resale market to improve overall profitability. We develop a model in which a group of risk-averse retailers sell a homogeneous product to their respective uncertain consumer markets. We study a scenario where an internal resale market can be constructed among the retailers and outside financial markets can be used to improve their ability to manage uncertainty. We identify strategies for retailers operating …

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Parameter Inference Of Queueing Models For It Systems Using End-To-End Measurements, Laura Wynter, Cathy H. Xia, Fan Zhang Jan 2006

Parameter Inference Of Queueing Models For It Systems Using End-To-End Measurements, Laura Wynter, Cathy H. Xia, Fan Zhang

Research Collection School Of Computing and Information Systems

As Information Technology (IT) matures and expands in the scope of available applications, IT systems increase at a fascinating rate in both size and complexity. For example, today, a typical Web service hosting center may have hundreds of nodes and dozens of different applications simultaneously running on it. Each of the nodes in turn has often multiple processors and layered caches. These nodes make use of both local and shared storage systems. The size and complexity of such systems make performance modeling much more difficult, if at all tractable. Detailed modeling, fine tuning and accurate analysis can be carried out …

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Using Social Development Lenses To Understand E-Government Development, Keng Siau, Y. Long Jan 2006

Using Social Development Lenses To Understand E-Government Development, Keng Siau, Y. Long

Research Collection School Of Computing and Information Systems

As governments at different levels and all around the world are increasingly using the Web to enhance and improve their services, understanding e-government development and exploring factors that affect e-government development have become important research topics. The purpose of this research is to investigate factors explaining e-government development in terms of social development lenses. Based on growth and regional development theories, the paper hypothesizes that income level, development status, and region are three factors that differentiate e- government development in countries. Group comparison tests are conducted using secondary data from the United Nations and the United Nations Development Programme. The …

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The Roles Of Digital Libraries In Teaching And Learning Geography, Chew-Hung Chang, John Hedberg, Tiong-Sa Teh, Ee Peng Lim Jan 2006

The Roles Of Digital Libraries In Teaching And Learning Geography, Chew-Hung Chang, John Hedberg, Tiong-Sa Teh, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Adopting a problem-centred approach helps students to learn Geography more effectively as they are able to identify and generalize about where different resources or activities are spatially located and they learn to associate certain patterns and processes with geographical changes. In an era where web-based student-centred inquiry is gaining popularity as a mode of learning Geography, the role of digital libraries as delivery trucks (in Clark’s terminology, 1983) needs to be better understood. An obvious affordance of the digital library is that it organizes information around themes for problems to be solved. This paper describes a developmental project to build …

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Multiagent Teamwork: Hybrid Approaches, Praveen Paruchuri, Emma Bowring, Ranjit Nair, Jonathan Pearce, Nathan Schurr, Milind Tambe, Pradeep Varakantham Jan 2006

Multiagent Teamwork: Hybrid Approaches, Praveen Paruchuri, Emma Bowring, Ranjit Nair, Jonathan Pearce, Nathan Schurr, Milind Tambe, Pradeep Varakantham

Research Collection School Of Computing and Information Systems

Today within the multiagent community, we see at least four competing methods to building multiagent systems: beliefdesireintention (BDI), distributed constraint optimization (DCOP), distributed POMDPs, and auctions or game-theoretic methods. While there is exciting progress within each approach, there is a lack of cross-cutting research. This article highlights the various hybrid techniques for multiagent teamwork developed by the teamcore group. In particular, for the past decade, the TEAMCORE research group has focused on building agent teams in complex, dynamic domains. While our early work was inspired by BDI, we will present an overview of recent research that uses DCOPs and distributed …

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Encouraging Knowledge Sharing In Knowledge-Based Organizations: Individual And Organizational Aspects Of Knowledge Management Leadership, Thomas Menkhoff, Yue Wah Chay, Benjamin Loh, Hans-Dieter Evers Jan 2006

Encouraging Knowledge Sharing In Knowledge-Based Organizations: Individual And Organizational Aspects Of Knowledge Management Leadership, Thomas Menkhoff, Yue Wah Chay, Benjamin Loh, Hans-Dieter Evers

Research Collection Lee Kong Chian School Of Business

This study aims to understand the antecedents of knowledge sharing behavior amongst tenant firms in Science and Technology Parks (STPs) which has been highlighted as a key factor for the development of an epistemic culture of innovation in STPs. Components of a model of knowledge management leadership with a focus on knowledge sharing and innovative value creation in STPs are developed inspired by the work of Nonaka, Nahapiet and Ghoshal, Guns and others. Collection of data on various relevant measures is ongoing, covering technology firms and STPs in Singapore and other Asian countries. Besides outlining model components and hypotheses, tentative …

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Monolithic Integration Of Collimating Fresnel Lens For Beam Quality Enhancement In Tapered High Power Laser Diode, F. K. Lau, Chyng Wen Tee, X. Zhao, K. A. Williams, R. V. Penty, I. H. White, M. Calligaro, M. Lecomte, O. Parillaud, N. Michel, M. Krakowski Jan 2006

Monolithic Integration Of Collimating Fresnel Lens For Beam Quality Enhancement In Tapered High Power Laser Diode, F. K. Lau, Chyng Wen Tee, X. Zhao, K. A. Williams, R. V. Penty, I. H. White, M. Calligaro, M. Lecomte, O. Parillaud, N. Michel, M. Krakowski

Research Collection Lee Kong Chian School Of Business

We demonstrate, for the first time, a monolithic integrated lens for wide aperture gain-guided tapered laser beam quality enhancement by compensating the quadratic phase curvature. The 3mm long tapered laser with an output aperture of 170μm adopted in this design consists of a gain-guided tapered section and an index-guided ridge section and operated at 980nm. The lens design is implemented by focus ion beam etching (FIBE) technique, whereby the laser diode is mounted p-side up in order to facilitate the etching process. The lens is located 600μm away from the junction of the tapered and ridge sections, and is 40μm …

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Visualization For Analyzing Trajectory-Based Metaheuristic Search Algorithms, Steven Halim, Roland H. C. Yap, Hoong Chuin Lau Jan 2006

Visualization For Analyzing Trajectory-Based Metaheuristic Search Algorithms, Steven Halim, Roland H. C. Yap, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

No abstract provided.

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Culture And Counterfactuals: On The Importance Of Life Domains, Jing Chen, Chi-Yue Chiu, Neal J. Roese, Kim-Pong Tam, Ivy Yee-Man Lau Jan 2006

Culture And Counterfactuals: On The Importance Of Life Domains, Jing Chen, Chi-Yue Chiu, Neal J. Roese, Kim-Pong Tam, Ivy Yee-Man Lau

Research Collection School of Social Sciences

Past research, with its emphasis on affective regulatory processes, has failed to find cross-cultural differences in counterfactual thoughts. In the current study, the authors examine the tendency to generate additive counterfactuals (those that focus on the addition of new aspects that were not in fact present) and subtractive counterfactuals (those that focus on subtraction of factual aspects) among Mainland Chinese and European American university students in five life domains: schoolwork, romantic relationships, family relationships, friendships, and life in general. As in previous studies, the authors find an overall main effect, in which additive counterfactuals predominate over subtractive counterfactuals within both …

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Guo Xiang, Alan Kam Leung Chan Jan 2006

Guo Xiang, Alan Kam Leung Chan

Research Collection College of Integrative Studies

A champion of the Learning of the Mysterious (Xuanxue) or neo-Daoism that gained prominence in third-century China, Guo Xiang (c. 252–312 CE) is best known for his commentary to the Zhuangzi, which offers to reconcile orthodox teachings (mingjiao) with Daoist naturalness (ziran).

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Accounting Restatements: Are They Always Bad News For Investors?, Dan Segal, Jeffrey L. Callen, Joshua Livnat Jan 2006

Accounting Restatements: Are They Always Bad News For Investors?, Dan Segal, Jeffrey L. Callen, Joshua Livnat

Research Collection School Of Accountancy

This study investigates a large sample of financial statement restatements over the period 1986-2001, and compares restatements caused by changes in accounting principles to those caused by errors. Typically, investors perceive restatements as negative signals due to three potential reasons: (a) the restatement indicates problems with the accounting system that may be manifestations of broader operational (and managerial) problems, (b) the restatement causes downward revisions in future cash flows expectations, and (c) the restatement indicates managerial attempts to cover up income decline through “cooking the books.” We provide evidence that market reactions to restatements due to errors are generally negative. …

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Transition Rule Elicitation Methods For Urban Cellular Automata Models, Junfeng Jiao, Luc Boerboom Jan 2006

Transition Rule Elicitation Methods For Urban Cellular Automata Models, Junfeng Jiao, Luc Boerboom

Research Collection College of Integrative Studies

In this chapter, transition rules used in urban CA models are reviewed and classified into two categories: transition potential rules and conflict resolution rules. Then, four widely used rule elicitation methods: Regression analysis, Artificial Neural network (ANN), Visual calibration, and Analytical Hierarchy Processing – Multi Criteria Evaluation (AHP-MCE) are discussed. Most of these methods are data driven methods and can be used to elicit the transition potential rules in the urban CA models. In the following, three possible rule elicitation methods: Interview, Document analysis, and Card sorting are explained and demonstrated. These three methods are driven by knowledge and can …

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Efficient Mining Of Group Patterns From User Movement Data, Yida Wang, Ee Peng Lim, San-Yih Hwang Jan 2006

Efficient Mining Of Group Patterns From User Movement Data, Yida Wang, Ee Peng Lim, San-Yih Hwang

Research Collection School Of Computing and Information Systems

In this paper, we present a new approach to derive groupings of mobile users based on their movement data. We assume that the user movement data are collected by logging location data emitted from mobile devices tracking users. We formally define group pattern as a group of users that are within a distance threshold from one another for at least a minimum duration. To mine group patterns, we first propose two algorithms, namely AGP and VG-growth. In our first set of experiments, it is shown when both the number of users and logging duration are large, AGP and VG-growth are …

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A Class Of Nonlinear Stochastic Volatility Models, Jun Yu, Zhenlin Yang Jan 2006

A Class Of Nonlinear Stochastic Volatility Models, Jun Yu, Zhenlin Yang

Research Collection School Of Economics

This paper proposes a class of nonlinear stochastic volatility models based on the Box-Cox transformation which offers an alternative to the one introduced in Andersen (1994). The proposed class encompasses many parametric stochastic volatility models that have appeared in the literature, including the well known lognormal stochastic volatility model, and has an advantage in the ease with which different specifications on stochastic volatility can be tested. In addition, the functional form of transformation which induces marginal normality of volatility is obtained as a byproduct of this general way of modeling stochastic volatility. The efficient method of moments approach is used …

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L S Penrose's Limit Theorem: Tests By Simulation, Pao Li Chang, Vincent Chua, Moshe Machover Jan 2006

L S Penrose's Limit Theorem: Tests By Simulation, Pao Li Chang, Vincent Chua, Moshe Machover

Research Collection School Of Economics

L S Penrose's Limit Theorem-which is implicit in Penrose (1952, p. 72) [Penrose, 1952. On the Objective Study of Crowd Behavior. H. K. Lewis and Co, London, p. 72] and for which he gave no rigorous proof-says that, in simple weighted voting games, if the number of voters increases indefinitely and the relative quota is pegged, then-under certain conditions-the ratio between the voting powers of any two voters converges to the ratio between their weights. Lindner and Machover (2004) [Lindner I., Machover M. 2004. L.S. Penrose's limit theorem: proof of some special cases. Mathematical Social Sciences 47, 37-49] prove some …

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Realized Variance And Market Microstructure Noise - Comment, Peter C. B. Phillips, Jun Yu Jan 2006

Realized Variance And Market Microstructure Noise - Comment, Peter C. B. Phillips, Jun Yu

Research Collection School Of Economics

No abstract provided.

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Semi-Parametric Inference In A Bivariate (Multivariate) Mixture Model, Denis H. Y. Leung, Jing Qin Jan 2006

Semi-Parametric Inference In A Bivariate (Multivariate) Mixture Model, Denis H. Y. Leung, Jing Qin

Research Collection School Of Economics

We consider estimation in a bivariate mixture model in which the component distributions can be decomposed into identical distributions. Previous approaches to estimation involve parametrizing the distributions. In this paper, we use a semi-parametric approach. The method is based on the exponential tilt model of Anderson (1979), where the log ratio of probability (density) functions from the bivariate components is linear in the observations. The proposed model does not require training samples, i.e., data with confirmed component membership. We show that in bivariate mixture models, parameters are identifiable. This is in contrast to previous works, where parameters are identifiable if …

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Coalition Formation Theories Revisited: An Empirical Investigation Of Aumann's Hypothesis, Vincent Chua, Dan S. Felsenthal Jan 2006

Coalition Formation Theories Revisited: An Empirical Investigation Of Aumann's Hypothesis, Vincent Chua, Dan S. Felsenthal

Research Collection School Of Economics

In one of the earliest attempts to examine the effect of a priori voting power on actual political phenomena, Riker (1959) looked at changes in party affiliation in the French National Assembly in 1953–54, and used these data to test the hypothesis that deputies who switched parties were seeking thereby to increase their a priori voting power. His findings were negative, or at best inconclusive.

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Commune-Level Estimation Of Poverty Measure And Its Application In Cambodia, Tomoki Fujii Jan 2006

Commune-Level Estimation Of Poverty Measure And Its Application In Cambodia, Tomoki Fujii

Research Collection School Of Economics

Cambodia is still suffering from the legacy of civil conflict after more than a decade. With over one-third of the population living below the poverty line, poverty remains one of the most serious problems in Cambodia. A number of governmental bodies, local and international nongovernmental organizations (NGOs), and international organizations operating in Cambodia have made eradicating poverty a priority and have established many social programmes to this end. In designing such programmes, the efficient allocation of resources is essential for making poverty alleviation more cost-effective. Targeting is often helpful for this purpose because one can avoid wasting resources on the …

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Using Cognitive Mapping Techniques To Supplement Uml And Up In Information Requirements Determination, Keng Siau, Tan Xin Jan 2006

Using Cognitive Mapping Techniques To Supplement Uml And Up In Information Requirements Determination, Keng Siau, Tan Xin

Research Collection School Of Computing and Information Systems

Information requirements determination is a critical task in system development projects. Many human issues may hinder the efforts to accurately capture and clearly understand users' information requirements. In this paper, we review the cognitive underpinnings of some human issues, which are discussed in existing literature and relevant to information requirements determination. We then propose the use of cognitive mapping techniques in the process of information requirements determination. Three widely used cognitive mapping techniques - causal mapping, semantic mapping, and concept mapping – are briefly introduced in this article. A case is used to illustrate how to use these cognitive mapping …

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E-Healthcare In Abc County Health Department (Abcchd): Trade-Offs Analysis And Evaluation, Keng Siau, Hwee-Joo Kam Jan 2006

E-Healthcare In Abc County Health Department (Abcchd): Trade-Offs Analysis And Evaluation, Keng Siau, Hwee-Joo Kam

Research Collection School Of Computing and Information Systems

The issue of privacy stirred a tumultuous uproar when the ABC County Health Department (ABCCHD) was planning for an e-Healthcare system that utilized information technology to streamline the administration process of patients. ABCCHD had hired a software vendor, Info-Health, a company that specialized in information system development for the healthcare industry to help in the project. The privacy of patients with Sexually Transmitted Diseases/Human Immunity System was a thorny issue in the implementation of the e-Healthcare system. A trade-off between privacy and cost was discussed and debated. Three alternatives, with varying degrees of privacy and cost, were considered.

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Systems Analysis & Design: An Essential Part Of Is Education, Albert L. Harris, Michael Lang, Briony J. Oates, Keng Siau Jan 2006

Systems Analysis & Design: An Essential Part Of Is Education, Albert L. Harris, Michael Lang, Briony J. Oates, Keng Siau

Research Collection School Of Computing and Information Systems

Systems analysis and design has been as critical building block in Information Systems (IS) education since the inception of the IS major. Whether it is taught using the traditional or "structured approach or the object-oriented approach, it exposes students to the different methods, tools, and techniques used in developing new systems, develops students analytical and problem-solving skills, teaches fact-finding and data gathering techniques, and provides teamwork skills. All of these are valuable skills for systems analysts. This paper introduces the reader of this special issue on systems analysis and design education to the issue, discusses the two approaches to teaching …

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Dividing Hedging And Gambling: Legal Implications Of Derivative Instruments, Christopher C. H. Chen Jan 2006

Dividing Hedging And Gambling: Legal Implications Of Derivative Instruments, Christopher C. H. Chen

Research Collection Yong Pung How School Of Law

The past three decades have seen the emergence in themarket of many different types of “derivativeinstruments”, ranging from futures, forwards, options,and swaps1 to some other hybrid instruments2 orsynthetic transactions3 . Along with insurance,derivative instruments help market participants notonly to hedge various types of risks but also to engagein market speculation. A derivative transaction couldserve the purpose of avoiding large losses (i.e. hedging)as well as earning a windfall (i.e. speculation). As such,one question arises: Is there any difference betweengambling and derivative trading?

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A Survey On Networking Games In Telecommunications, E. Altman, T. Boulogne, R. El-Azouzi, T. Jiménez, Laura Wynter Jan 2006

A Survey On Networking Games In Telecommunications, E. Altman, T. Boulogne, R. El-Azouzi, T. Jiménez, Laura Wynter

Research Collection School Of Computing and Information Systems

In this survey, we summarize different modeling and solution concepts of networking games, as well as a number of different applications in telecommunications that make use of or can make use of networking games. We identify some of the mathematical challenges and methodologies that are involved in these problems. We include here work that has relevance to networking games in telecommunications from other areas, in particular from transportation planning.

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Advances In Data Modeling Research, G. Allen, A. Bajaj, V. Khatri, S. Ram, Keng Siau Jan 2006

Advances In Data Modeling Research, G. Allen, A. Bajaj, V. Khatri, S. Ram, Keng Siau

Research Collection School Of Computing and Information Systems

In this paper, we summarize the discussions of the panel on "Advances in Data Modeling Research," held at the Americas Conference on Information Systems (AMCIS) in 2005. We focus on four primary areas where data modeling research offers rich opportunities: spatio-temporal semantics, genome research, ontological analysis and empirical evaluation of existing models. We highlight past work in each area and also discuss open questions, with a view to promoting future research in the overall data modeling area.

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Grid-Partition Index: A Hybrid Approach To Nearest-Neighbor Queries In Wireless Location-Based Services, Baihua Zheng, Jianliang Xu, Wang-Chien Lee, Dik Lun Lee Jan 2006

Grid-Partition Index: A Hybrid Approach To Nearest-Neighbor Queries In Wireless Location-Based Services, Baihua Zheng, Jianliang Xu, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Traditional nearest-neighbor (NN) search is based on two basic indexing approaches: object-based indexing and solution-based indexing. The former is constructed based on the locations of data objects: using some distance heuristics on object locations. The latter is built on a precomputed solution space. Thus, NN queries can be reduced to and processed as simple point queries in this solution space. Both approaches exhibit some disadvantages, especially when employed for wireless data broadcast in mobile computing environments. In this paper, we introduce a new index method, called the grid-partition index, to support NN search in both ondemand access and periodic broadcast …

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Towards Better Quality Specification Miners, David Lo, Siau-Cheng Khoo Jan 2006

Towards Better Quality Specification Miners, David Lo, Siau-Cheng Khoo

Research Collection School Of Computing and Information Systems

Softwares are often built without specification. Tools to automatically extract specification from software are needed and many techniques have been proposed. One type of these specifications – temporal API specification – is often specified in the form of automaton (i.e., FSA/PFSA). There have been many work on mining software temporal specification using dynamic analysis techniques; i.e., analysis of software program traces. Unfortunately, the issues of scalability, robustness and accuracy of these techniques have not been comprehensively addressed. In this paper, we describe a framework that enables assessments of the performance of a specification miner in generating temporal specification of software …

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In-Network Join Processing For Sensor Networks, Hai Yu, Ee Peng Lim, Jun Zhang Jan 2006

In-Network Join Processing For Sensor Networks, Hai Yu, Ee Peng Lim, Jun Zhang

Research Collection School Of Computing and Information Systems

Recent advances in hardware and wireless technologies have led to sensor networks consisting of large number of sensors capable of gathering and processing data collectively. Query processing on these sensor networks has to consider various inherent constraints. While simple queries such as select and aggregate queries in wireless sensor networks have been addressed in the literature, the processing of join queries in sensor networks remains to be investigated. In this paper, we present a synopsis join strategy for evaluating join queries in sensor networks with communication efficiency. In this strategy, instead of directly joining two relations distributed in a sensor …

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