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On Joint Modelling And Testing For Local And Global Spatial Externalities, Zhenlin Yang Oct 2006

On Joint Modelling And Testing For Local And Global Spatial Externalities, Zhenlin Yang

Research Collection School Of Economics

This paper concerns the joint modeling, estimation and testing for local and global spatial externalities. Spatial externalities have become in recent years a standard notion of economic research activities in relation to social interactions, spatial spillovers and dependence, etc., and have received an increasing attention by econometricians and applied researchers. While conceptually the principle underlying the spatial dependence is straightforward, the precise way in which this dependence should be included in a regression model is complex. Following the taxonomy of Anselin (2003, International Regional Science Review 26, 153-166), a general model is proposed, which takes into account jointly local and …

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Lottery Rather Than Waiting-Line Auction, Winston T. H. Koh, Zhenlin Yang, Lijing Zhu Oct 2006

Lottery Rather Than Waiting-Line Auction, Winston T. H. Koh, Zhenlin Yang, Lijing Zhu

Research Collection School Of Economics

This paper investigates the allocative efficiency of two non-price allocation mechanisms – the lottery (random allocation) and the waiting-line auction (queue system) – for the cases where consumers possess identical time costs (the homogeneous case), and where time costs are correlated with time valuations (the heterogeneous case). We show that the relative efficiency of the two mechanisms depends critically on a scarcity factor (measured by the ratio of the number of objects available for allocation over the number of participants) and on the shape of the distribution of valuations. We show that the lottery dominates the waiting-line auction for a …

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Corporate Crisis Planning: Tensions, Issues, And Contradictions, A. Pang, Fritz Cropp, Glen T. Cameron Oct 2006

Corporate Crisis Planning: Tensions, Issues, And Contradictions, A. Pang, Fritz Cropp, Glen T. Cameron

Research Collection Lee Kong Chian School Of Business

Purpose – Crisis planning, which symbolizes an organization's crisis preparedness and often conceptualized at the corporate headquarters, is increasingly decentralized to regional centers of global companies. These centers, in turn, synchronize their crisis master plans with its national units for expeditious management of localized crises. The purpose of this paper is to capture the decision-making processes that practitioners at a regional center faced as they nurtured their master plan from conception to implementation. Design/methodology/approach – The qualitative method is used. This is a case study of a Fortune 500 company with plants in every continent. The company has four regional …

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Service Pattern Discovery Of Web Service Mining In Web Service Registry-Repository, Qianhui Althea Liang, Jen-Yao Chung, Steven M. Miller, Yang Ouyang Oct 2006

Service Pattern Discovery Of Web Service Mining In Web Service Registry-Repository, Qianhui Althea Liang, Jen-Yao Chung, Steven M. Miller, Yang Ouyang

Research Collection School Of Computing and Information Systems

This paper presents and elaborates the concept of Web service usage patterns and pattern discovery through service mining. We define three different levels of service usage data: i) user request level, ii) template level and iii) instance level. At each level, we investigate patterns of service usage data and the discovery of these patterns. An algorithm for service pattern discovery at the template level is presented. We show the system architecture of a service-mining enabled service registry repository. Web service patterns, pattern discovery and pattern mining supports the discovery and composition of complex services, which in turn supports the application …

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Two-Instant Reallocation In Two-Echelon Spare Parts Inventory Systems, Huawei Song, Hoong Chuin Lau Oct 2006

Two-Instant Reallocation In Two-Echelon Spare Parts Inventory Systems, Huawei Song, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In this paper, we study the problem of deciding when and how to perform reallocation of existing spare parts in a multi-echelon reparable item inventory system. We present a mathematical model that solves the problem when there are two reallocation instants, in response to the open challenge post by Cao and Silver(2005) to consider two or more possible reallocations within a replenishment cycle.

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Audio Similarity Measure By Graph Modeling And Matching, Yuxin Peng, Chong-Wah Ngo, Cuihua Fang, Xiaoou Chen, Jianguo Xiao Oct 2006

Audio Similarity Measure By Graph Modeling And Matching, Yuxin Peng, Chong-Wah Ngo, Cuihua Fang, Xiaoou Chen, Jianguo Xiao

Research Collection School Of Computing and Information Systems

This paper proposes a new approach for the similarity measure and ranking of audio clips by graph modeling and matching. Instead of using frame-based or salient-based features to measure the acoustical similarity of audio clips, segment-based similarity is proposed. The novelty of our approach lies in two aspects: segment-based representation, and the similarity measure and ranking based on four kinds of similarity factors. In segmentbased representation, segments not only capture the change property of audio clip, but also keep and present the change relation and temporal order of audio features. In the similarity measure and ranking, four kinds of similarity …

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Natural Document Clustering By Clique Percolation In Random Graphs, Wei Gao, Kam-Fai Wong Oct 2006

Natural Document Clustering By Clique Percolation In Random Graphs, Wei Gao, Kam-Fai Wong

Research Collection School Of Computing and Information Systems

Document clustering techniques mostly depend on models that impose explicit and/or implicit priori assumptions as to the number, size, disjunction characteristics of clusters, and/or the probability distribution of clustered data. As a result, the clustering effects tend to be unnatural and stray away more or less from the intrinsic grouping nature among the documents in a corpus. We propose a novel graph-theoretic technique called Clique Percolation Clustering (CPC). It models clustering as a process of enumerating adjacent maximal cliques in a random graph that unveils inherent structure of the underlying data, in which we unleash the commonly practiced constraints in …

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Extracting Link Chains Of Relationship Instances From A Website, Myo-Myo Naing, Ee Peng Lim, Roger Hsiang-Li Chiang Oct 2006

Extracting Link Chains Of Relationship Instances From A Website, Myo-Myo Naing, Ee Peng Lim, Roger Hsiang-Li Chiang

Research Collection School Of Computing and Information Systems

Web pages from a Web site can often be associated with concepts in an ontology, and pairs of Web pages also can be associated with relationships between concepts. With such associations, the Web site can be searched, browsed, or even reorganized based on the concept and relationship labels of its Web pages. In this article, we study the link chain extraction problem that is critical to the extraction of Web pages that are related. A link chain is an ordered list of anchor elements linking two Web pages related by some semantic relationship. We propose a link chain extraction method …

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Privacy Enhanced Superdistribution Of Layered Content With Trusted Access Control, Daniel J. T. Chong, Robert H. Deng Oct 2006

Privacy Enhanced Superdistribution Of Layered Content With Trusted Access Control, Daniel J. T. Chong, Robert H. Deng

Research Collection School Of Computing and Information Systems

Traditional superdistribution approaches do not address consumer privacy issues and also do not reliably prevent the malicious consumer from indiscriminately copying and redistributing the decryption keys or the decrypted content. The layered nature of common digital content can also be exploited to efficiently provide the consumer with choices over the quality of the content, allowing him/her to pay less for lower quality consumption and vice versa. This paper presents a system that superdistributes encrypted layered content and (1) allows the consumer to select a quality level at which to decrypt and consume the content; (2) prevents the merchant from knowing …

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Viz: A Visual Analysis Suite For Explaining Local Search Behavior, Steven Halim, Roland H. C. Yap, Hoong Chuin Lau Oct 2006

Viz: A Visual Analysis Suite For Explaining Local Search Behavior, Steven Halim, Roland H. C. Yap, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

NP-hard combinatorial optimization problems are common in real life. Due to their intractability, local search algorithms are often used to solve such problems. Since these algorithms are heuristic-based, it is hard to understand how to improve or tune them. We propose an interactive visualization tool, VIZ, meant for understanding the behavior of local search. VIZ uses animation of abstract search trajectories with other visualizations which are also animated in a VCR-like fashion to graphically playback the algorithm behavior. It combines generic visualizations applicable on arbitrary algorithms with algorithm and problem specific visualizations. We use a variety of techniques such as …

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Non-Critical Waveguide Alignment For Vertically-Coupled Microring Using A Mode-Expanded Bus Architecture, Chyng Wen Tee, K. A. Williams, R. V. Penty, I. H. White Oct 2006

Non-Critical Waveguide Alignment For Vertically-Coupled Microring Using A Mode-Expanded Bus Architecture, Chyng Wen Tee, K. A. Williams, R. V. Penty, I. H. White

Research Collection Lee Kong Chian School Of Business

Vertically coupled microrings in an all-pass filter configuration are fabricated with a range of waveguide misalignments deliberately introduced into the lithography masks to demonstrate noncritical fabrication requirements. The microrings have a mode-expanded bus design which allows a greatly reduced variation in power coupling coefficient-only 6% for fabrication misalignments as high as 1 mum. This represents a five-fold improvement in fabrication tolerance when compared with conventional designs.

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Who? Whom? Reparations And The Problem Of Agency, Chandran Kukathas Sep 2006

Who? Whom? Reparations And The Problem Of Agency, Chandran Kukathas

Research Collection School of Social Sciences

If a person is wronged, whether by a physical violation of his person or by having his property unjustly taken, or even by the besmirching of his reputation, he is, most people agree, entitled to some form of compensation or restitution from the person or persons responsible for the wrong. What form the reparation should take, and how great it should be, are sometimes difficult problems, but this does not change the fact that something is owed and someone must be held to account. If a restaurant goes bust because a supplier fails to fulfill his commitments and a newspaper …

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Novartis's Alex Gorsky: Ensuring That Patients Get Access To The Medicines They Need, Knowledge@Smu Sep 2006

Novartis's Alex Gorsky: Ensuring That Patients Get Access To The Medicines They Need, Knowledge@Smu

Knowledge@SMU

Alex Gorsky was named head of Pharma North America and CEO of Novartis Pharmaceuticals Corp., the U.S. affiliate of Swiss drug giant Novartis, in the fall of 2005. Since joining the company in 2004 as chief operating officer and head of general medicines, Gorsky has overseen the continued growth of Novartis's industry-leading cardiovascular franchise, notably the blockbuster drugs Diovan and Lotrel. The company sells a variety of products, including those that treat endocrine and respiratory disease, gastrointestinal illnesses, cancer and blood disorders and bone and joint conditions, among others. Prior to joining Novartis, Gorsky was company group chairman for Johnson …

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Set Inference For Semiparametric Discrete Games, Kyoo-Il Kim Sep 2006

Set Inference For Semiparametric Discrete Games, Kyoo-Il Kim

Research Collection School Of Economics

We consider estimation and inference of parameters in discrete games allowing for multiple equilibria, without using an equilibrium selection rule. We do a set inference while a game model can contain infinite dimensional parameters. Examples can include signaling games with discrete types where the type distribution is nonparametrically specified and entry-exit games with partially linear payoffs functions. A consistent set estimator and a confidence interval of a function of parameters are provided in this paper. We note that achieving a consistent point estimation often requires an information reduction. Due to this less use of information, we may end up a …

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Performance, Growth And Earnings Management, Chi Wen Jevons Lee, Laura Yue Li, Heng Yue Sep 2006

Performance, Growth And Earnings Management, Chi Wen Jevons Lee, Laura Yue Li, Heng Yue

Research Collection School Of Accountancy

We study the relationship between the amount of managed earnings and firms' earnings performance and expected growth in a reporting model, where managers manipulate earnings to influence the valuation of firms' equity while bearing a cost that is increasing and convex in the amount of managed earnings. In the unique revealing equilibrium to the model, firms with higher performance and growth over-report earnings by a larger amount because price responsiveness increases with earnings performance and growth. And earnings quality, defined as the proportion of true economic earnings in total reported earnings, increases with earnings performance but decreases with earnings growth. …

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Escalation And De-Escalation Of Commitment To Information Systems Projects: Insights From A Project Evaluation Model, Shan Ling Pan, Gary S. C. Pan, Michael Newman, Donal Flynn Sep 2006

Escalation And De-Escalation Of Commitment To Information Systems Projects: Insights From A Project Evaluation Model, Shan Ling Pan, Gary S. C. Pan, Michael Newman, Donal Flynn

Research Collection School Of Accountancy

This paper outlines a project evaluation model for examining escalation and de-escalation of commitment to information systems projects. We view escalation and de-escalation of commitment as processes involving recurring instances of approach-avoidance conflict. In the model, the sequential mapping of project events is integrated with a model of approach-avoidance conflict that identifies periods of gradual evolution at two separate levels of social analysis (project and work) that are punctuated by sudden, revolutionary periods of rapid change. By conceiving the processes of commitment escalation and de-escalation as sequences of events involving approach-avoidance conflicts, researchers may develop a deeper understanding of how …

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The Boundary Spanner’S Role In Organisational Learning: Unleashing Untapped Potential, Siu Loon Hoe Sep 2006

The Boundary Spanner’S Role In Organisational Learning: Unleashing Untapped Potential, Siu Loon Hoe

Research Collection School Of Computing and Information Systems

PurposeThe organizational behavior and management literature has devoted a lot attention on processes and technology in organizational learning. There has been little work to examine the role of boundary spanners in organizational learning. The purpose of this paper is to highlight the importance of boundary spanners in enhancing organizational learning.Design/methodology/approachThe existing boundary spanning literature was reviewed and the salient points on their role in organizational learning discussed.Practical implicationsThe paper offers a view on tapping the hidden potential of boundary spanners in organizations in order to enhance the organization's learning capacity form the external environment. Practicing manager would then be able …

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Multi-Learner Based Recursive Supervised Training, Laxmi R. Iyer, Kiruthika Ramanathan, Sheng-Uei Guan Sep 2006

Multi-Learner Based Recursive Supervised Training, Laxmi R. Iyer, Kiruthika Ramanathan, Sheng-Uei Guan

Research Collection School Of Computing and Information Systems

In this paper, we propose the multi-learner based recursive supervised training (MLRT) algorithm, which uses the existing framework of recursive task decomposition, by training the entire dataset, picking out the best learnt patterns, and then repeating the process with the remaining patterns. Instead of having a single learner to classify all datasets during each recursion, an appropriate learner is chosen from a set of three learners, based on the subset of data being trained, thereby avoiding the time overhead associated with the genetic algorithm learner utilized in previous approaches. In this way MLRT seeks to identify the inherent characteristics of …

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Multi-Learner Based Recursive Supervised Training, Laxmi R. Iyer, Kiruthika Ramanathan, Sheng-Uei Guan Sep 2006

Multi-Learner Based Recursive Supervised Training, Laxmi R. Iyer, Kiruthika Ramanathan, Sheng-Uei Guan

Research Collection School Of Computing and Information Systems

In this paper, we propose the multi-learner based recursive supervised training (MLRT) algorithm, which uses the existing framework of recursive task decomposition, by training the entire dataset, picking out the best learnt patterns, and then repeating the process with the remaining patterns. Instead of having a single learner to classify all datasets during each recursion, an appropriate learner is chosen from a set of three learners, based on the subset of data being trained, thereby avoiding the time overhead associated with the genetic algorithm learner utilized in previous approaches. In this way MLRT seeks to identify the inherent characteristics of …

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Masking Page Reference Patterns In Encryption Databases On Untrusted Storage, Xi Ma, Hwee Hwa Pang, Kian-Lee Tan Sep 2006

Masking Page Reference Patterns In Encryption Databases On Untrusted Storage, Xi Ma, Hwee Hwa Pang, Kian-Lee Tan

Research Collection School Of Computing and Information Systems

To support ubiquitous computing, the underlying data have to be persistent and available anywhere-anytime. The data thus have to migrate from devices that are local to individual computers, to shared storage volumes that are accessible over open network. This potentially exposes the data to heightened security risks. In particular, the activity on a database exhibits regular page reference patterns that could help attackers learn logical links among physical pages and then launch additional attacks. We propose two countermeasures to mitigate the risk of attacks initiated through analyzing the shared storage server’s activity for those page patterns. The first countermeasure relocates …

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Three Architectures For Trusted Data Dissemination In Edge Computing, Shen-Tat Goh, Hwee Hwa Pang, Robert H. Deng, Feng Bao Sep 2006

Three Architectures For Trusted Data Dissemination In Edge Computing, Shen-Tat Goh, Hwee Hwa Pang, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

Edge computing pushes application logic and the underlying data to the edge of the network, with the aim of improving availability and scalability. As the edge servers are not necessarily secure, there must be provisions for users to validate the results—that values in the result tuples are not tampered with, that no qualifying data are left out, that no spurious tuples are introduced, and that a query result is not actually the output from a different query. This paper aims to address the challenges of ensuring data integrity in edge computing. We study three schemes that enable users to check …

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Cuhk At Imageclef 2005: Cross-Language And Cross Media Image Retrieval, Steven Hoi, Jianke Zhu, Michael R. Lyu Sep 2006

Cuhk At Imageclef 2005: Cross-Language And Cross Media Image Retrieval, Steven Hoi, Jianke Zhu, Michael R. Lyu

Research Collection School Of Computing and Information Systems

In this paper, we describe our studies of cross-language and cross-media image retrieval at the ImageCLEF 2005. This is the first participation of our CUHK (The Chinese University of Hong Kong) group at ImageCLEF. The task in which we participated is the “bilingual ad hoc retrieval” task. There are three major focuses and contributions in our participation. The first is the empirical evaluation of language models and smoothing strategies for cross-language image retrieval. The second is the evaluation of cross-media image retrieval, i.e., combining text and visual contents for image retrieval. The last is the evaluation of bilingual image retrieval …

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Optimal Order Quantities With Remanufacturing Across New Product Generations, Shantanu Bhattacharya, V Daniel R. Guide, Luk N. Van Wassenhove Sep 2006

Optimal Order Quantities With Remanufacturing Across New Product Generations, Shantanu Bhattacharya, V Daniel R. Guide, Luk N. Van Wassenhove

Research Collection Lee Kong Chian School Of Business

We address the problem of determining the optimal retailer order quantities from a manufacturer who makes new products in conjunction with ordering remanufactured products from a remanufacturer using used and unsold products from the previous product generation. Specifically, we determine the optimal order quantity by the retailer for four systems of decision-making: (a) the three firms make their decisions in a coordinated fashion, (b) the retailer acts independently while the manufacturer and remanufacturer coordinate their decisions, (c) the remanufacturer acts independently while the retailer and manufacturer coordinate their decisions, and (d) all three firms act independently. We model the four …

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Of Dreams And Bubbles: Right-Sizing Home Ownership, Tan K. B. Eugene Sep 2006

Of Dreams And Bubbles: Right-Sizing Home Ownership, Tan K. B. Eugene

Research Collection Yong Pung How School Of Law

Is public housing now seen more as a consumption good or investment good? And with all that has been said about an 'asset ,bubble', should we be worrying about an 'expectations trap' instead? Assistant Professor Eugene Tan and Associate Professor Sing Tien Foo give their take on what the changes augur.

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Mining Rdf Metadata For Generalized Association Rules, Tao Jiang, Ah-Hwee Tan Sep 2006

Mining Rdf Metadata For Generalized Association Rules, Tao Jiang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

In this paper, we present a novel frequent generalized pattern mining algorithm, called GP-Close, for mining generalized associations from RDF metadata. To solve the over-generalization problem encountered by existing methods, GP-Close employs the notion of generalization closure for systematic over-generalization reduction. Empirical experiments conducted on real world RDF data sets show that our method can substantially reduce pattern redundancy and perform much better than the original generalized association rule mining algorithm Cumulate in term of time efficiency.

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Discovering Image-Text Associations For Cross-Media Web Information Fusion, Tao Jiang, Ah-Hwee Tan Sep 2006

Discovering Image-Text Associations For Cross-Media Web Information Fusion, Tao Jiang, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

The diverse and distributed nature of the information published on the World Wide Web has made it difficult to collate and track information related to specific topics. Whereas most existing work on web information fusion has focused on multiple document summarization, this paper presents a novel approach for discovering associations between images and text segments, which subsequently can be used to support cross-media web content summarization. Specifically, we employ a similarity-based multilingual retrieval model and adopt a vague transformation technique for measuring the information similarity between visual features and textual features. The experimental results on a terrorist domain document set …

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Is Stock Price Rounded For Economic Reasons In The Chinese Market, Yan He, Chunchi Wu Sep 2006

Is Stock Price Rounded For Economic Reasons In The Chinese Market, Yan He, Chunchi Wu

Research Collection Lee Kong Chian School Of Business

This paper investigates whether trading and quoting prices are rounded for both economic and cultural reasons on the Shanghai and Shenzhen Stock Exchanges in China. We find that the close, bid, and ask prices of domestic shares are rounded to the nearest 10s and 5s for economic reasons, and the last decimal point of prices clusters on 8 for cultural reasons. The cross-sectional variation in 10-cent and 5-cent rounding can be well explained by price and inverse of square root of trading volume, whereas the clustering on 8 can hardly be ascribed to economic variables. The cross-sectional variation in execution …

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Bucket Brigades On In-Tree Assembly Networks, John J. Bartholdi, Iii, Donald D. Eisenstein, Yun Fong Lim Sep 2006

Bucket Brigades On In-Tree Assembly Networks, John J. Bartholdi, Iii, Donald D. Eisenstein, Yun Fong Lim

Research Collection Lee Kong Chian School Of Business

In a of subassembly lines, balance becomes more difficult to achieve as it requires that all subassembly lines be synchronized to produce at the same rate. We show how to adapt the ‘‘bucket brigade’’ protocol of work-sharing so that balance emerges spontaneously.

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Verbal And Nonverbal Impression Management Tactics In Behavior Description And Situational Interviews, Helga Peeters, Filip Lievens Sep 2006

Verbal And Nonverbal Impression Management Tactics In Behavior Description And Situational Interviews, Helga Peeters, Filip Lievens

Research Collection Lee Kong Chian School Of Business

This study investigated how structured interview formats, instructions to convey favorable impressions, and applicants' individual differences influenced the use and effectiveness of verbal and nonverbal impression management (IM). Results from 190 people who were screened for a training program demonstrated that interview format affected the kind of tactics used, which in turn positively influenced interviewer evaluations. Behavior description interviews triggered self-focused (and defensive) tactics, whereas situational interviews triggered other-focused tactics. Instructions to convey a desirable impression also enhanced the use of specific tactics (self-focused and other-focused verbal IM tactics) and moderated the effects of individual differences on IM use. IM …

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An Agent-Based Model Of Crisis-Driven Ethnic Migration, Michael Makowsky, Tamas Makany, Patrick Meier, Jorge Tavares Sep 2006

An Agent-Based Model Of Crisis-Driven Ethnic Migration, Michael Makowsky, Tamas Makany, Patrick Meier, Jorge Tavares

Research Collection Lee Kong Chian School Of Business

The literature on ethnic migration suggests that natural disasters, armed conflict, economics and cultural networks are key drivers of migration. The dearth of georeferenced ethnic data, however, limits the value of econometric analysis. We build an agent-based model to simulate crisis-driven migration. Agents within a multi-ethnic population monitor their spatial environments to formulate perceptions of the risk of being persecuted. The expected utility of staying within a given neighborhood is inversely related to the perceived probability of persecution. Cultural networks temper an agent's security calculus, with strong social ties dampening the human security dilemma. Agents express preferences regarding the different …

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