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Real-Time Evaluation Of Email Campaign Performance, Andre Bonfrer, Xavier Dreze Oct 2008

Real-Time Evaluation Of Email Campaign Performance, Andre Bonfrer, Xavier Dreze

Research Collection Lee Kong Chian School Of Business

We develop a testing methodology that can be used to predict the performance of e-mail marketing campaigns in real time. We propose a split-hazard model that makes use of a time transformation (a concept we call virtual time) to allow for the estimation of straightforward parametric hazard functions and generate early predictions of an individual campaign's performance (as measured by open and click propensities). We apply this pretesting methodology to 25 e-mail campaigns and find that the method is able to produce in an hour and fifteen minutes estimates that are more accurate and more reliable than those that the …

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Pareto-Optimal Predictor Composite Formation: A Complementary Approach To Alleviating The Selection Quality/Adverse Impact Dilemma, Paul R. Sackett, Wilfried De Corte, Filip Lievens Sep 2008

Pareto-Optimal Predictor Composite Formation: A Complementary Approach To Alleviating The Selection Quality/Adverse Impact Dilemma, Paul R. Sackett, Wilfried De Corte, Filip Lievens

Research Collection Lee Kong Chian School Of Business

In our rejoinder to the comments of Kehoe (this issue) and Potosky, Bobko and Roth (this issue) we emphasize that our proposal on Pareto-optimal predictor composite formation is a complementary and not a competitive alternative for reducing the tension between selection quality and adverse impact. Our work addresses the decisions to be made once one has decided to use a predictor composite. We also further clarify the basic features of Pareto-optimal tradeoffs and Pareto-optimal composites within the context of personnel selection. In particular, we indicate that Pareto-optimal tradeoffs between validity and adverse impact emerge because these goals are different and …

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Development And Test Of A Model Of External Organizational Commitment In Human Resources Outsourcing, Filip Lievens, Wilfried De Corte Sep 2008

Development And Test Of A Model Of External Organizational Commitment In Human Resources Outsourcing, Filip Lievens, Wilfried De Corte

Research Collection Lee Kong Chian School Of Business

Most prior outsourcing studies in the human resources domain have focused on the initial decision for outsourcing HR activities. Hence, little is known about HR managers' commitment to continue an already existing outsourcing relationship. This study constitutes a first step to increase our understanding of the factors related to the continuity of HR outsourcing relationships. We developed and tested a model of HR managers' (N = 186) commitment in outsourcing relationships. Affective commitment or the desire for the outsourcing relationship to continue was related to the depth and frequency of HR outsourcing. Conversely, continuance commitment, which refers to the constraints …

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Validity And Adverse Impact Potential Of Predictor Composite Formation, Wilfried De Corte, Filip Lievens, Paul R. Sackett Sep 2008

Validity And Adverse Impact Potential Of Predictor Composite Formation, Wilfried De Corte, Filip Lievens, Paul R. Sackett

Research Collection Lee Kong Chian School Of Business

Previous research on the validity and adverse impact (AI) of predictor composite formation focused on the merits of regression-based or ad hoc composites. We argue for a broader focus. Ad hoc chosen composites are usually not Pareto-optimal, whereas the regression-based composite represents only one element from the total set of Pareto-optimal composites and can, therefore, provide only limited information on the potential for validity and AI reduction of forming predictor composites when both validity and AI are of concern. In that case, other Pareto-optimal composites may provide a better benchmark to decide on the merits of the predictor composite formation. …

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Improving Semiparametric Estimation By Using Surrogate Data, Song Xi Chen, Leung, Denis H. Y., Jin Qin Sep 2008

Improving Semiparametric Estimation By Using Surrogate Data, Song Xi Chen, Leung, Denis H. Y., Jin Qin

Research Collection School Of Economics

The paper considers estimating a parameter beta that defines an estimating function U(y, x, beta) for an outcome variable y and its covariate x when the outcome is missing in some of the observations. We assume that, in addition to the outcome and the covariate, a surrogate outcome is available in every observation. The efficiency of existing estimators for beta depends critically on correctly specifying the conditional expectation of U given the surrogate and the covariate. When the conditional expectation is not correctly specified, which is the most likely scenario in practice, the efficiency of estimation can be severely compromised …

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Tuning Into The Digital Channel: Evaluating Business Model Fit For Internet Firm Survival, Robert J. Kauffman, Bin Wang Sep 2008

Tuning Into The Digital Channel: Evaluating Business Model Fit For Internet Firm Survival, Robert J. Kauffman, Bin Wang

Research Collection School Of Computing and Information Systems

More than 5,000 Internet firms have failed since the beginning of 2000. One common perception is that the downturn in the economy drove many firms out of business. But then, why have some firms survived? In this research, we provide an empirical analysis by examining how the business model characteristics of an Internet firm affect its survival. We analyze a panel data set of 130 public Internet firms using two different techniques: non-parametric survival analysis, and the semiparametric Cox proportional hazards model. We characterize the survival rates throughout the lifetimes of the public Internet firms in our sample. Our results …

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Tagnsearch: Searching And Navigating Geo-Referenced Collections Of Photographs, Quang Minh Nguyen, Thi Nhu Quynh Kim, Dion Hoe-Lian Goh, Yin-Leng Theng, Ee Peng Lim, Aixin Sun, Chew-Hung Chang, Kalyani Chatterjea Sep 2008

Tagnsearch: Searching And Navigating Geo-Referenced Collections Of Photographs, Quang Minh Nguyen, Thi Nhu Quynh Kim, Dion Hoe-Lian Goh, Yin-Leng Theng, Ee Peng Lim, Aixin Sun, Chew-Hung Chang, Kalyani Chatterjea

Research Collection School Of Computing and Information Systems

TagNSearch is a map-based tool for searching and browsing geo-tagged photographs based on their associated tags. Using Flickr as the dataset, TagNSearch returns, for a given query, photographs clustered by locations, and summarizes each cluster of photographs by cluster-specific tags. A map-based interface is also provided to help users better search, navigate and browse photographs and their clusters. A qualitative evaluation comparing TagNSearch and an existing tag search support in Flickr was also conducted. The task involved finding locations associated with a set of photographs. Participants were found to perform this task better using TagNSearch than Flickr.

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Analyst Coverage And The Cost Of Raising Equity Capital: Evidence From Underpricing Of Seasoned Equity Offerings, Robert M. Bowen, Xia Chen, Qiang Cheng Sep 2008

Analyst Coverage And The Cost Of Raising Equity Capital: Evidence From Underpricing Of Seasoned Equity Offerings, Robert M. Bowen, Xia Chen, Qiang Cheng

Research Collection School Of Accountancy

Theorists have long recognized that information asymmetry among investors adversely affects the cost of raising equity capital (e.g., Diamond and Verrecchia 1991). When there is information asymmetry, relatively uninformed investors are reluctant to trade because of higher potential loss from transacting with informed investors (e.g., Glosten and Milgrom 1985; Kyle 1985). To trade, uninformed investors demand compensation for the risks of trading with informed investors (O’Hara 2003). In the case of issuing new equity, firms must issue shares at a discount to overcome the reluctance of uninformed investors. Such discounting leads to smaller proceeds to the firm and a higher …

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An Efficient Pir Construction Using Trusted Hardware, Yanjiang Yang, Xuhua Ding, Robert H. Deng, Feng Bao Sep 2008

An Efficient Pir Construction Using Trusted Hardware, Yanjiang Yang, Xuhua Ding, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

For a private information retrieval (PIR) scheme to be deployed in practice, low communication complexity and low computation complexity are two fundamental requirements it must meet. Most existing PIR schemes only focus on the communication complexity. The reduction on the computational complexity did not receive the due treatment mainly because of its O(n) lower bound. By using the trusted hardware based model, we design a novel scheme which breaks this barrier. With constant storage, the computation complexity of our scheme, including offline computation, is linear to the number of queries and is bounded by after optimization.

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Home Biased Analysts In Emerging Markets, Sandy Lai, Melvyn Teo Sep 2008

Home Biased Analysts In Emerging Markets, Sandy Lai, Melvyn Teo

Research Collection Lee Kong Chian School Of Business

We find that local analyst recommendations are systematically more optimistic than foreign analyst recommendations in emerging markets. The effects of this novel home bias among local analysts overwhelm any information asymmetry between foreign and local analysts. Consequently, local analyst upgrades underperform foreign analyst upgrades, while local analyst downgrades outperform foreign analyst downgrades. Neither foreign investors, local institutions, nor retail investors appear to be fully cognizant of this bias. Trade reactions suggest that foreign investors overestimate the bias in foreign analyst recommendations while local institutions underestimate the bias in local analyst recommendations. These results are pervasive across countries, time periods, and …

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Subprime Lending: Did It Lead To The Real Estate Boom And Bust?, Knowledge@Smu Aug 2008

Subprime Lending: Did It Lead To The Real Estate Boom And Bust?, Knowledge@Smu

Knowledge@SMU

Is there a link between the availability of aggressive home loan lending and the price of homes? In a paper presented at the Far East and South Asian Meeting of the Econometric Society 2008, hosted by the Singapore Management University, Wharton professors Susan Wachter and Andrey Pavlov show that it is the fluctuation in the use of aggressive instruments which exacerbates the market downturns, and not the fact that such instruments generate higher default rates.

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Momentum And Informed Trading, A. Hameed, Dong Hong, Mitchell Craig Warachka Aug 2008

Momentum And Informed Trading, A. Hameed, Dong Hong, Mitchell Craig Warachka

Research Collection Lee Kong Chian School Of Business

Consistent with the predictions of Wang (1994), we document that firm-specific informed trading is an important determinant of price momentum. The stronger return continuation in stocks with more informed trading cannot be explained by cross-sectional differences in uncertainty proxies such as analyst forecast dispersion, analyst coverage, idiosyncratic return volatility, and size. The relationship between informed trading and return continuation is also not attributable to cross-sectional differences in liquidity. Instead, our evidence emphasizes the role of price discovery in generating short-term price momentum.

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An Integrated Decision– Making Approach For Improving European Air Traffic Management, Yael Gruksha-Cockayne, Bert De Reyck, Zeger Degraeve Aug 2008

An Integrated Decision– Making Approach For Improving European Air Traffic Management, Yael Gruksha-Cockayne, Bert De Reyck, Zeger Degraeve

Research Collection Lee Kong Chian School Of Business

We develop a multistakeholder, multicriteria decision-making framework for Eurocontrol, the European air traffic management organization, for evaluating and selecting operational improvements to the air traffic management system. The selected set of improvements will form the master plan of the Single European Sky initiative for harmonizing air traffic, in an effort to cope with the forecasted increase in air traffic, while maintaining safety, protecting the environment, and improving predictability and efficiency. The challenge is to select the set of enhancements such that the required performance targets are met and all key stakeholders are committed to the decisions. In this paper, we …

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A Nonparametric Hellinger Metric Test For Conditional Independence, Liangjun Su, Halbert White Aug 2008

A Nonparametric Hellinger Metric Test For Conditional Independence, Liangjun Su, Halbert White

Research Collection School Of Economics

We propose a nonparametric test of conditional independence based on the weighted Hellinger distance between the two conditional densities, f(y|x,z) and f(y|x), which is identically zero under the null. We use the functional delta method to expand the test statistic around the population value and establish asymptotic normality under β-mixing conditions. We show that the test is consistent and has power against alternatives at distance n−1/2h−d/4. The cases for which not all random variables of interest are continuously valued or observable are also discussed. Monte Carlo simulation results indicate that the test behaves reasonably well in …

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Hierarchical Inter-Object Traces For Specification Mining, David Lo, Shahar Maoz Aug 2008

Hierarchical Inter-Object Traces For Specification Mining, David Lo, Shahar Maoz

Research Collection School Of Computing and Information Systems

Major challenges of dynamic analysis approaches to specification mining include scalability over long traces as well as comprehensibility and expressivity of results. We present a novel use of object hierarchies over inter-object traces as an abstraction/refinement mechanism enabling scalable, incremental, top-down mining of scenario-based specifications.

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A Lightweight Buyer-Seller Watermarking Protocol, Yongdong Wu, Hwee Hwa Pang Aug 2008

A Lightweight Buyer-Seller Watermarking Protocol, Yongdong Wu, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

The buyer-seller watermarking protocol enables a seller to successfully identify a traitor from a pirated copy, while preventing the seller from framing an innocent buyer. Based on finite field theory and the homomorphic property of public key cryptosystems such as RSA, several buyer-seller watermarking protocols (N. Memon and P. W. Wong (2001) and C.-L. Lei et al. (2004)) have been proposed previously. However, those protocols require not only large computational power but also substantial network bandwidth. In this paper, we introduce a new buyer-seller protocol that overcomes those weaknesses by managing the watermarks. Compared with the earlier protocols, ours is …

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Simulating A Smartboard By Real-Time Gesture Detection In Lecture Videos, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong Aug 2008

Simulating A Smartboard By Real-Time Gesture Detection In Lecture Videos, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

Gesture plays an important role for recognizing lecture activities in video content analysis. In this paper, we propose a real-time gesture detection algorithm by integrating cues from visual, speech and electronic slides. In contrast to the conventional "complete gesture" recognition, we emphasize detection by the prediction from "incomplete gesture". Specifically, intentional gestures are predicted by the modified hidden Markov model (HMM) which can recognize incomplete gestures before the whole gesture paths are observed. The multimodal correspondence between speech and gesture is exploited to increase the accuracy and responsiveness of gesture detection. In lecture presentation, this algorithm enables the on-the-fly editing …

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Knowledge Transfer Via Multiple Model Local Structure Mapping, Jing Gao, Wei Fan, Jing Jiang, Jiawei Han Aug 2008

Knowledge Transfer Via Multiple Model Local Structure Mapping, Jing Gao, Wei Fan, Jing Jiang, Jiawei Han

Research Collection School Of Computing and Information Systems

The effectiveness of knowledge transfer using classification algorithms depends on the difference between the distribution that generates the training examples and the one from which test examples are to be drawn. The task can be especially difficult when the training examples are from one or several domains different from the test domain. In this paper, we propose a locally weighted ensemble framework to combine multiple models for transfer learning, where the weights are dynamically assigned according to a model's predictive power on each test example. It can integrate the advantages of various learning algorithms and the labeled information from multiple …

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Managerial Ownership And Firms' Information Environment, Soongsoo Han, Tony Kang, Gerald Lobo Aug 2008

Managerial Ownership And Firms' Information Environment, Soongsoo Han, Tony Kang, Gerald Lobo

Research Collection School Of Accountancy

We examine the relation between managerial stock ownership and the firm’s information environment. We focus on three dimensions of the information environment: total, public, and private information precision (Barron, Kim, Lim and Stevens 1998). Our results suggest that firms’ total and public information precision are positively related to managerial ownership. In contrast, there is no clear pattern in private information precision across different levels of managerial ownership. We also observe that managerial ownership has a greater impact on the firm’s public information environment after the implementation of Regulation Fair Disclosure, suggesting that the regulation was effective in improving the firms’ …

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Does Earnings Quality Affect Information Asymmetry: Evidence From Trading Costs, Nilabhra Bhattacharya, Hemang Desai, Kumar Venkataraman Aug 2008

Does Earnings Quality Affect Information Asymmetry: Evidence From Trading Costs, Nilabhra Bhattacharya, Hemang Desai, Kumar Venkataraman

Research Collection School Of Accountancy

The adverse consequences of poor earnings quality have been the subject of significant debate among academics, practitioners and regulators. However, the empirical evidence on pricing implications of earnings quality is sparse and controversial. We examine one potential consequence of poor earnings quality - its impact on information asymmetry. We document that poor earnings quality increases the adverse selection risk as manifested in trading costs and lowers liquidity in financial markets. Both innate and discretionary components of earnings quality contribute significantly to information asymmetry. Further, poor earnings quality exacerbates information asymmetry around earnings announcements, especially for firms where earnings represent the …

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Authenticating The Query Results Of Text Search Engines, Hwee Hwa Pang, Kyriakos Mouratidis Aug 2008

Authenticating The Query Results Of Text Search Engines, Hwee Hwa Pang, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

The number of successful attacks on the Internet shows that it is very difficult to guarantee the security of online search engines. A breached server that is not detected in time may return incorrect results to the users. To prevent that, we introduce a methodology for generating an integrity proof for each search result. Our solution is targeted at search engines that perform similarity-based document retrieval, and utilize an inverted list implementation (as most search engines do). We formulate the properties that define a correct result, map the task of processing a text search query to adaptations of existing threshold-based …

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Classification In P2p Networks By Bagging Cascade Rsvms, Hock Hee Ang, Vikvekanand Gopalkrishnan, Steven C. H. Hoi, Wee Keong Ng, Anwitaman Datta Aug 2008

Classification In P2p Networks By Bagging Cascade Rsvms, Hock Hee Ang, Vikvekanand Gopalkrishnan, Steven C. H. Hoi, Wee Keong Ng, Anwitaman Datta

Research Collection School Of Computing and Information Systems

Data mining tasks in P2P are bound by issues like scalability, peer dynamism, asynchronism, and data privacy preservation. These challenges pose difficulties for deploying conventional machine learning techniques in P2P networks, which may be hard to achieve classification accuracies comparable to regular centralized solutions. We recently investigated the classification problem in P2P networks and proposed a novel P2P classification approach by cascading Reduced Support Vector Machines (RSVM). Although promising results were obtained, the existing solution has some drawback of redundancy in both communication and computation. In this paper, we present a new approach to over the limitation of the previous …

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Understanding Factors Influencing Proficient Information Systems Usage, Brenda Eschenbrenner, Fiona Fui-Hoon Nah Aug 2008

Understanding Factors Influencing Proficient Information Systems Usage, Brenda Eschenbrenner, Fiona Fui-Hoon Nah

Research Collection School Of Computing and Information Systems

Variations exist among information system (IS) users’ abilities to effectively utilize an IS. Some users are able to maximize IS potential, while others are not. This research proposes to understand the attributes of individuals who are most capable of exploiting IS to its fullest potential as well as the management and organizational factors that facilitate the development of highly competent users. The Repertory Grid Technique was utilized to identify user attributes contributing to IS proficiency in Phase One of this research and will be utilized to identify management and organizational factors in Phase Two. The results will provide a comprehensive …

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Critical Success Factors In Soa Implementation, J. Erickson, Keng Siau Aug 2008

Critical Success Factors In Soa Implementation, J. Erickson, Keng Siau

Research Collection School Of Computing and Information Systems

Service Oriented Architecture (SOA) has become flavor du jour for many businesses. Seemingly, almost every company has implemented, is in the midst of implementing or is seriously considering a SOA project. A critical question many organizations are facing now is – what are the critical success factors for SOA implementations? This research aims to identify a list of factors relating to SOA implementation success. A Delphi study forms the research method, and inputs regarding SOA critical success factors are requested from a panel of experts.

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Mining Patterns And Rules For Software Specification Discovery, David Lo, Siau-Cheng Khoo Aug 2008

Mining Patterns And Rules For Software Specification Discovery, David Lo, Siau-Cheng Khoo

Research Collection School Of Computing and Information Systems

Software specifications are often lacking, incomplete and outdated in the industry. Lack and incomplete specifications cause various software engineering problems. Studies have shown that program comprehension takes up to 45% of software development costs. One of the root causes of the high cost is the lack-of documented specification. Also, outdated and incomplete specification might potentially cause bugs and compatibility issues. In this paper, we describe novel data mining techniques to mine or reverse engineer these specifications from the pool of software engineering data. A large amount of software data is available for analysis. One form of software data is program …

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Being Naive About Naive Diversification: Can Investment Theory Be Consistently Useful?, Jun Tu, Guofu Zhou Aug 2008

Being Naive About Naive Diversification: Can Investment Theory Be Consistently Useful?, Jun Tu, Guofu Zhou

Research Collection Lee Kong Chian School Of Business

The modern portfolio theory pioneered by Markowitz (1952) is widely used in practice and taught in MBA texts. DeMiguel, Garlappi and Uppal (2007), however, show that, due to estimation errors, existing theory-based portfolio strategies are not as good as we once thought, and the estimation window needed for them to beat the naive $1/N$ strategy (that invests equally across N risky assets) is 'around 3000 months for a portfolio with 25 assets and about 6000 months for a portfolio with 50 assets.' In this paper, we modify the modern portfolio theory to account for estimation errors, so that the theory …

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Strategic Orientation Of High-Technology Firms In A Transitional Economy, Chung-Ming Lau, Daphne W. Yiu, Ping-Kwong Yeung, Yuan Lu Jul 2008

Strategic Orientation Of High-Technology Firms In A Transitional Economy, Chung-Ming Lau, Daphne W. Yiu, Ping-Kwong Yeung, Yuan Lu

Research Collection Lee Kong Chian School Of Business

Strategic orientation is a critical factor for a firm's competitiveness in a transitional economy context but it is understudied in the current literature. This article examines the antecedents of strategic orientation from both the socio-cognitive and resource-based view perspectives. The study posits that the strategic orientations of firms in a transitional economy context are influenced by the top managers' cognitions and organizational resources. Based on a national survey of high-technology firms in China, the study finds that a stronger market-focused strategic orientation was facilitated by managerial cognitions about the future of the industry and current operation and performance of the …

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Estimating Local Optimums In Em Algorithm Over Gaussian Mixture Model, Zhenjie Zhang, Bing Tian Dai, Anthony K.H. Tung Jul 2008

Estimating Local Optimums In Em Algorithm Over Gaussian Mixture Model, Zhenjie Zhang, Bing Tian Dai, Anthony K.H. Tung

Research Collection School Of Computing and Information Systems

EM algorithm is a very popular iteration-based method to estimate the parameters of Gaussian Mixture Model from a large observation set. However, in most cases, EM algorithm is not guaranteed to converge to the global optimum. Instead, it stops at some local optimums, which can be much worse than the global optimum.

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A Self-Organizing Neural Model For Multimedia Information Fusion, Luong-Dong Nguyen, Kia-Yan Woon, Ah-Hwee Tan Jul 2008

A Self-Organizing Neural Model For Multimedia Information Fusion, Luong-Dong Nguyen, Kia-Yan Woon, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

This paper presents a self-organizing network model for the fusion of multimedia information. By synchronizing the encoding of information across multiple media channels, the neural model known as fusion Adaptive Resonance Theory (fusion ART) generates clusters that encode the associative mappings across multimedia information in a real-time and continuous manner. In addition, by incorporating a semantic category channel, fusion ART further enables multimedia information to be fused into predefined themes or semantic categories. We illustrate the fusion ART’s functionalities through experiments on two multimedia data sets in the terrorist domain and show the viability of the proposed approach.

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Searching Correlated Objects In A Long Sequence, Ken C. K. Lee, Wang-Chien Lee, Donna Peuquet, Baihua Zheng Jul 2008

Searching Correlated Objects In A Long Sequence, Ken C. K. Lee, Wang-Chien Lee, Donna Peuquet, Baihua Zheng

Research Collection School Of Computing and Information Systems

Sequence, widely appearing in various applications (e.g. event logs, text documents, etc) is an ordered list of objects. Exploring correlated objects in a sequence can provide useful knowledge among the objects, e.g., event causality in event log and word phrases in documents. In this paper, we introduce correlation query that finds correlated pairs of objects often appearing closely to each other in a given sequence. A correlation query is specified by two control parameters, distance bound, the requirement of object closeness, and correlation threshold, the minimum requirement of correlation strength of result pairs. Instead of processing the query by scanning …

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