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Can A Representative Agent Model Represent A Heterogeneous Agent Economy?, Sungbae An, Yongsung Chang, Sun-Bin Kim Nov 2008

Can A Representative Agent Model Represent A Heterogeneous Agent Economy?, Sungbae An, Yongsung Chang, Sun-Bin Kim

Research Collection School Of Economics

Accounting for observed fluctuations in aggregate employment, consumption, and real wage using the optimality conditions of a representative household requires preferences that are incompatible with economic priors. In order to reconcile theory with data, we construct a model with heterogeneous agents whose decisions are difficult to aggregate because of incomplete capital markets and the indivisible nature of labor supply. If we were to explain the model-generated aggregate time series using decisions of a stand-in household, such a household must have a nonconcave or unstable utility as is often found with the aggregate US data.

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Virtual World Affordances: Enhancing Brand Value, S. Park, Fiona Fui-Hoon Nah, D. Dewester, B. Eschenbrenner, S. Jeon Nov 2008

Virtual World Affordances: Enhancing Brand Value, S. Park, Fiona Fui-Hoon Nah, D. Dewester, B. Eschenbrenner, S. Jeon

Research Collection School Of Computing and Information Systems

Virtual worlds are three-dimensional, computer-generated worlds that are a natural extension of the existing Internet. Although many businesses are jumping on the bandwagon to maintain a presence in virtual worlds, there is no well-established knowledge or theory to guide businesses in their involvement in these environments. In this paper, we identify affordances in the virtual worlds that can be used to increase the state of flow experienced in a business virtual site, which in turn may enhance brand equity, or the perceived added value of a brand to customers. We present a conceptual model that can be used to guide …

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Two-Factor Mutual Authentication Based On Smart Cards And Passwords, Guomin Yang, Duncan S. Wong, Huaxiong Wang, Xiaotie Deng Nov 2008

Two-Factor Mutual Authentication Based On Smart Cards And Passwords, Guomin Yang, Duncan S. Wong, Huaxiong Wang, Xiaotie Deng

Research Collection School Of Computing and Information Systems

One of the most commonly used two-factor user authentication mechanisms nowadays is based on smart-card and password. A scheme of this type is called a smart-card-based password authentication scheme. The core feature of such a scheme is to enforce two-factor authentication in the sense that the client must have the smart-card and know the password in order to gain access to the server. In this paper, we scrutinize the security requirements of this kind of schemes, and propose a new scheme and a generic construction framework for smart-card-based password authentication. We show that a secure password based key exchange protocol …

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Bias And Controversy In Evaluation Systems, Hady Wirawan Lauw, Ee Peng Lim, Ke Wang Nov 2008

Bias And Controversy In Evaluation Systems, Hady Wirawan Lauw, Ee Peng Lim, Ke Wang

Research Collection School Of Computing and Information Systems

Evaluation is prevalent in real life. With the advent of Web 2.0, online evaluation has become an important feature in many applications that involve information (e.g., video, photo, and audio) sharing and social networking (e.g., blogging). In these evaluation settings, a set of reviewers assign scores to a set of objects. As part of the evaluation analysis, we want to obtain fair reviews for all the given objects. However, the reality is that reviewers may deviate in their scores assigned to the same object, due to the potential bias of reviewers or controversy of objects. The statistical approach of averaging …

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Money Largely Accounts For Increased Unemployment During Stagflation, Shows A Recent Study, Knowledge@Smu Oct 2008

Money Largely Accounts For Increased Unemployment During Stagflation, Shows A Recent Study, Knowledge@Smu

Knowledge@SMU

Is there a relation between money, measured by inflation or interest rates, and unemployment? According to Aleksander Berensten, Guido Menzio and Randall Wright -- co-authors of a recent paper on “Inflation and Unemployment in the Long Run” -- there is a strong positive relation. Wright, who is professor of economics at Wharton, presented a seminar based on their paper at the Singapore Management University’s School of Economics.

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Unpacking Sources Of Comparative Advantage: A Quantitative Approach, Davin Chor Oct 2008

Unpacking Sources Of Comparative Advantage: A Quantitative Approach, Davin Chor

Research Collection School Of Economics

This paper develops an approach for quantifying the relative importance of different sources of comparative advantage for country welfare in a global trade equilibrium. To explain the pattern of specialization, I present a multi-country, perfectly-competitive Ricardian model that extends Eaton and Kortum (2002) to predict industry trade flows. In this framework, comparative advantage is determined by the interaction of country and industry characteristics, with countries specializing in industries whose specific production needs they are best able to meet with their factor endowments, institutional environment, and technological strengths. I estimate the model parameters using a large dataset of bilateral trade flows, …

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Using English Information In Non-English Web Search, Wei Gao, Wei Gao, Ming Zhou Oct 2008

Using English Information In Non-English Web Search, Wei Gao, Wei Gao, Ming Zhou

Research Collection School Of Computing and Information Systems

The leading web search engines have spent a decade building highly specialized ranking functions for English web pages. One of the reasons these ranking functions are effective is that they are designed around features such as PageRank, automatic query and domain taxonomies, and click-through information, etc. Unfortunately, many of these features are absent or altered in other languages. In this work, we show how to exploit these English features for a subset of Chinese queries which we call linguistically non-local (LNL). LNL Chinese queries have a minimally ambiguous English translation which also functions as a good English query. We first …

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Model Checking Csp Revisited: Introducing A Process Analysis Toolkit, Jun Sun, Yang Liu, Jin Song Dong Oct 2008

Model Checking Csp Revisited: Introducing A Process Analysis Toolkit, Jun Sun, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

FDR, initially introduced decades ago, is the de facto analyzer for Communicating Sequential Processes (CSP). Model checking techniques have been evolved rapidly since then. This paper describes PAT, i.e., a process analysis toolkit which complements FDR in several aspects. PAT is designed to analyze event-based compositional system models specified using CSP as well as shared variables and asynchronous message passing. It supports automated refinement checking, model checking of LTL extended with events, etc. In this paper, we highlight how partial order reduction is applied to improve refinement checking in PAT. Experiment results show that PAT outperforms FDR in some cases.

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Event Detection With Common User Interests, Meishan Hu, Aixin Sun, Ee Peng Lim Oct 2008

Event Detection With Common User Interests, Meishan Hu, Aixin Sun, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In this paper, we aim at detecting events of common user interests from huge volume of user-generated content. The degree of interest from common users in an event is evidenced by a significant surge of event-related queries issued to search for documents (e.g., news articles, blog posts) relevant to the event. Taking the stream of queries from users and the stream of documents as input, our proposed framework seamlessly integrates the two streams into a single stream of query profiles. A query profile is a set of documents matching a query at a given time. With the single stream of …

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Specification Mining Of Symbolic Scenario-Based Models, David Lo, Shahar Maoz Oct 2008

Specification Mining Of Symbolic Scenario-Based Models, David Lo, Shahar Maoz

Research Collection School Of Computing and Information Systems

Many dynamic analysis approaches to specification mining, which extract behavioral models from execution traces, do not consider object identities. This limits their power when used to analyze traces of general object oriented programs. In this work we present a novel specification mining approach that considers object identities, and, moreover, generalizes from specifications involving concrete objects to their symbolic class-level abstractions. Our approach uses data mining methods to extract significant scenario-based specifications in the form of Damm and Harel's live sequence charts (LSC), a formal and expressive extension of classic sequence diagrams. We guarantee that all mined symbolic LSCs are significant …

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Spreadsheet Data Resampling For Monte-Carlo Simulation, Thin Yin Leong, Wee Leong Lee Oct 2008

Spreadsheet Data Resampling For Monte-Carlo Simulation, Thin Yin Leong, Wee Leong Lee

Research Collection School Of Computing and Information Systems

The pervasiveness of spreadsheets software resulted in its increased application as a simulation tool for business analysis. Random values generation supporting such evaluations using spreadsheets are simple and yet powerful. However, the typical approach to Monte-Carlo simulations, which is what simulations with stochasticity are called, requires significant amount of time to be spent on data collection, data collation, and distribution function fitting. In fact, the latter can be overwhelming for undergraduate students to learn and do properly in a short time. Resampling eliminates both the need to fit distributions to the sample data, and to perform the ensuing tests of …

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Ceo Characteristics, Ceo-Firm Match And Corporate Refocus Value, Sheng Huang Oct 2008

Ceo Characteristics, Ceo-Firm Match And Corporate Refocus Value, Sheng Huang

Research Collection Lee Kong Chian School Of Business

This paper investigates how CEO characteristics affect firm value through divestiture. Using a novel dataset tracking CEO’s career path, from which CEO’s talent and expertise are reasonably inferred, I find when CEOs have differing abilities across divisions of conglomerates, they more likely divest divisions that they are less qualified to manage, and focus on divisions of better match with their talents and expertise. The better match of their talents with firms’ retained assets is the source of value creation from refocusing divestiture. Divestitures that increase corporate focus but not improve the talent-asset match do not create value in long run. …

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Remote Attestation On Program Execution, Liang Gu, Xuhua Ding, Robert H. Deng, Bing Xie, Hong Mei Oct 2008

Remote Attestation On Program Execution, Liang Gu, Xuhua Ding, Robert H. Deng, Bing Xie, Hong Mei

Research Collection School Of Computing and Information Systems

Remote attestation provides the basis for one platform to establish trusts on another. In this paper, we consider the problem of attesting the correctness of program executions. We propose to measure the target program and all the objects it depends on, with an assumption that the Secure Kernel and the Trusted Platform Module provide a secure execution environment through process separation. The attestation of the target program begins with a program analysis on the source code or the binary code in order to find out the relevant executables and data objects. Whenever such a data object is accessed or a …

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Bayesian Tensor Approach For 3-D Face Modeling, Dacheng Tao, Mingli Song, Xuelong Li, Jialie Shen, Jimeng Sun, Xindong Wu, Christos Faloutsos, Stephen J. Maybank Oct 2008

Bayesian Tensor Approach For 3-D Face Modeling, Dacheng Tao, Mingli Song, Xuelong Li, Jialie Shen, Jimeng Sun, Xindong Wu, Christos Faloutsos, Stephen J. Maybank

Research Collection School Of Computing and Information Systems

Effectively modeling a collection of three-dimensional (3-D) faces is an important task in various applications, especially facial expression-driven ones, e.g., expression generation, retargeting, and synthesis. These 3-D faces naturally form a set of second-order tensors-one modality for identity and the other for expression. The number of these second-order tensors is three times of that of the vertices for 3-D face modeling. As for algorithms, Bayesian data modeling, which is a natural data analysis tool, has been widely applied with great success; however, it works only for vector data. Therefore, there is a gap between tensor-based representation and vector-based data analysis …

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An Effective Approach To 3d Deformable Surface Tracking, Jianke Zhu, Steven C. H. Hoi, Zenglin Xu, Michael R. Lyu Oct 2008

An Effective Approach To 3d Deformable Surface Tracking, Jianke Zhu, Steven C. H. Hoi, Zenglin Xu, Michael R. Lyu

Research Collection School Of Computing and Information Systems

The key challenge with 3D deformable surface tracking arises from the difficulty in estimating a large number of 3D shape parameters from noisy observations. A recent state-of-the-art approach attacks this problem by formulating it as a Second Order Cone Programming (SOCP) feasibility problem. The main drawback of this solution is the high computational cost. In this paper, we first reformulate the problem into an unconstrained quadratic optimization problem. Instead of handling a large set of complicated SOCP constraints, our new formulation can be solved very efficiently by resolving a set of sparse linear equations. Based on the new framework, a …

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Specifying And Verifying Sensor Networks: An Experiment Of Formal Methods, Jin Song Dong, Jing Sun, Jun Sun, Kenji Taguchi, Xian Zhang Oct 2008

Specifying And Verifying Sensor Networks: An Experiment Of Formal Methods, Jin Song Dong, Jing Sun, Jun Sun, Kenji Taguchi, Xian Zhang

Research Collection School Of Computing and Information Systems

With the development of sensor technology and electronic miniaturization, wireless sensor networks have shown a wide range of promising applications as well as challenges. Early stage sensor network analysis is critical, which allows us to reveal design errors before sensor deployment. Due to their distinguishable features, system specification and verification of sensor networks are highly non-trivial tasks. On the other hand, numerous formal theories and analysis tools have been developed in formal methods community, which may offer a systematic method for formal analysis of sensor networks. This paper presents our attempt on applying formal methods to sensor network specification/verification. An …

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Selection Of Concept Detectors For Video Search By Ontology-Enriched Semantic Spaces, Xiao-Yong Wei, Chong-Wah Ngo, Yu-Gang Jiang Oct 2008

Selection Of Concept Detectors For Video Search By Ontology-Enriched Semantic Spaces, Xiao-Yong Wei, Chong-Wah Ngo, Yu-Gang Jiang

Research Collection School Of Computing and Information Systems

This paper describes the construction and utilization of two novel semantic spaces, namely Ontology-enriched Semantic Space (OSS) and Ontology-enriched Orthogonal Semantic Space (OS2), to facilitate the selection of concept detectors for video search. These two semantic spaces are enriched with ontology knowledge, while emphasizing consistent and uniform comparison of ontological relatedness among concepts for query-to-concept mapping. OS2, in addition to being a linear space like OSS, also guarantees orthogonality of the semantic space. Compared with other ontology reasoning measures, both spaces are capable of providing platforms that offer a global view of concept inter-relatedness, by allowing evaluation of concept similarity …

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The Campaign Value Of Incumbency: A New Solution To The Puzzle Of Less Effective Incumbent Spending, Kenneth Benoit, Michael Marsh Oct 2008

The Campaign Value Of Incumbency: A New Solution To The Puzzle Of Less Effective Incumbent Spending, Kenneth Benoit, Michael Marsh

Research Collection School of Social Sciences

A puzzle in research on campaign spending is that while expenditure is positively related to votes won, this effect is far more strongly, or even exclusively, enjoyed by challengers rather than by incumbents. We unearth a new explanation for the puzzle, focusing on the hidden, yet variable, campaign value of office perquisites which incumbents deploy in their campaigns to win votes. When these variable office benefits are unobserved, then the effect is to make observed incumbent spending less effective than spending by challengers. Using data from the 2002 Irish general election, where incumbency was assigned a variable campaign value and …

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Audit Profile: The Auditor-General's Office Of Singapore, Soo Ping Lim Oct 2008

Audit Profile: The Auditor-General's Office Of Singapore, Soo Ping Lim

Research Collection School Of Accountancy

No abstract provided.

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Link Layer Multicast Using Smart Antennas: No Client Left Behind, Souvik Sen, Jie Xiong, Rahul Ghosh, Romit Roy Choudhury Oct 2008

Link Layer Multicast Using Smart Antennas: No Client Left Behind, Souvik Sen, Jie Xiong, Rahul Ghosh, Romit Roy Choudhury

Research Collection School Of Computing and Information Systems

Wireless link layer multicast is an important service primitive for emerging applications, such as live video, streaming audio, and other content telecasts. The broadcast nature of the wireless channel is amenable to multicast because a single packet transmission may be received by all clients in the multicast group. However, in view of diverse channel conditions at different clients, the rate of such a transmission is bottlenecked by the rate of the weakest client. Multicast throughput degrades severely. Attempts to increase the data rate result in lower reliability and higher unfairness. This paper utilizes smart beamforming antennas to improve multicast performance …

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Video Event Detection Using Motion Relativity And Visual Relatedness, Feng Wang, Yu-Gang Jiang, Chong-Wah Ngo Oct 2008

Video Event Detection Using Motion Relativity And Visual Relatedness, Feng Wang, Yu-Gang Jiang, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Event detection plays an essential role in video content analysis. However, the existing features are still weak in event detection because: i) most features just capture what is involved in an event or how the event evolves separately, and thus cannot completely describe the event; ii) to capture event evolution information, only motion distribution over the whole frame is used which proves to be noisy in unconstrained videos; iii) the estimated object motion is usually distorted by camera movement. To cope with these problems, in this paper, we propose a new motion feature, namely Expanded Relative Motion Histogram of Bag-ofVisual-Words …

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Near-Duplicate Keyframe Retrieval By Nonrigid Image Matching, Jianke Zhu, Steven C. H. Hoi, Michael R. Lyu, Shuicheng Yan Oct 2008

Near-Duplicate Keyframe Retrieval By Nonrigid Image Matching, Jianke Zhu, Steven C. H. Hoi, Michael R. Lyu, Shuicheng Yan

Research Collection School Of Computing and Information Systems

Near-duplicate image retrieval plays an important role in many real-world multimedia applications. Most previous approaches have some limitations. For example, conventional appearance-based methods may suffer from the illumination variations and occlusion issue, and local feature correspondence-based methods often do not consider local deformations and the spatial coherence between two point sets. In this paper, we propose a novel and effective Nonrigid Image Matching (NIM) approach to tackle the task of near-duplicate keyframe retrieval from real-world video corpora. In contrast to previous approaches, the NIM technique can recover an explicit mapping between two near-duplicate images with a few deformation parameters and …

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Resource-Aware Video Multicasting Via Access Gateways In Wireless Mesh Networks, Wanqing Tu, Cormac J. Sreenan, Chun Tung Chou, Archan Misra Oct 2008

Resource-Aware Video Multicasting Via Access Gateways In Wireless Mesh Networks, Wanqing Tu, Cormac J. Sreenan, Chun Tung Chou, Archan Misra

Research Collection School Of Computing and Information Systems

This paper studies video multicasting in large scale areas using wireless mesh networks. The focus is on the use of Internet access gateways that allow a choice of alternative routes to avoid potentially lengthy multi-hop wireless paths with low capacity. A set of heuristic-based algorithms are described that together aim to maximize network capacity: the two-tier integrated architecture algorithm, the weighted gateway uploading algorithm, the link-controlled routing tree algorithm, and the alternative channel assignment algorithm. These algorithms use different approaches to arrange multicast group members into a clustered and two-tier integrated architecture in which network protocols can make use of …

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A Comparative Account Of Statutory Interpretation In Singapore, Yihan Goh Oct 2008

A Comparative Account Of Statutory Interpretation In Singapore, Yihan Goh

Research Collection Yong Pung How School Of Law

In 1993, the Singapore Parliament enacted legislative provisions adapted from Australian legislation directing, inter alia, that the courts apply the purposive approach in statutory interpretation. Those provisions also allowed for the extended use of extrinsic materials in the interpretative process. Fifteen years on, there is now a considerable body of Singapore case law to which a meaningful analysis may be undertaken. Indeed, from an initially cautious application of the enacted legislation, the courts began to read the enactments expansively, eventually providing for a statutory interpretation regime that is largely free of the confines of old. Nonetheless, the Singapore position does …

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Recursive Pattern Based Hybrid Supervised Training, Kiruthika Ramanathan, Sheng Uei Guan Oct 2008

Recursive Pattern Based Hybrid Supervised Training, Kiruthika Ramanathan, Sheng Uei Guan

Research Collection School Of Computing and Information Systems

We propose, theorize and implement the Recursive Pattern-based Hybrid Supervised (RPHS) learning algorithm. The algorithm makes use of the concept of pseudo global optimal solutions to evolve a set of neural networks, each of which can solve correctly a subset of patterns. The pattern-based algorithm uses the topology of training and validation data patterns to find a set of pseudo-optima, each learning a subset of patterns. It is therefore well adapted to the pattern set provided. We begin by showing that finding a set of local optimal solutions is theoretically equivalent, and more efficient, to finding a single global optimum …

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Ontology Enhanced Web Image Retrieval: Aided By Wikipedia And Spreading Activation Theory, Huan Wang, Xing Jiang, Liang-Tien Chia, Ah-Hwee Tan Oct 2008

Ontology Enhanced Web Image Retrieval: Aided By Wikipedia And Spreading Activation Theory, Huan Wang, Xing Jiang, Liang-Tien Chia, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Ontology, as an efective approach to bridge the semantic gap in various domains, has attracted a lot of interests from multimedia researchers. Among the numerous possibilities enabled by ontology, we are particularly interested in exploiting ontology for a better understanding of media task (particularly, images) on the World Wide Web. To achieve our goal, two open issues are inevitably involved: 1) How to avoid the tedious manual work for ontology construction? 2) What are the effective inference models when using an ontology? Recent works about ontology learned from Wikipedia has been reported in conferences targeting the areas of knowledge management …

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Structuring Low-Quality Videotaped Lectures For Cross-Reference Browsing By Video Text Analysis, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong Oct 2008

Structuring Low-Quality Videotaped Lectures For Cross-Reference Browsing By Video Text Analysis, Feng Wang, Chong-Wah Ngo, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

This paper presents an unified approach in analyzing and Structuring the content of videotaped lectures for distance learning applications. By Structuring lecture videos, we can Support topic indexing and semantic querying of multimedia documents captured in the traditional classrooms. Our goal in this paper is to automatically construct the cross references of lecture videos and textual documents so as to facilitate the synchronized browsing and presentation of multimedia information. The major issues involved in our approach are topical event detection, video text analysis and the matching of slide shots and external documents. In topical event detection, a novel transition detector …

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Fusing Semantics, Observability, Reliability And Diversity Of Concept Detectors For Video Search, Xiao-Yong Wei, Chong-Wah Ngo Oct 2008

Fusing Semantics, Observability, Reliability And Diversity Of Concept Detectors For Video Search, Xiao-Yong Wei, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Effective utilization of semantic concept detectors for large-scale video search has recently become a topic of intensive studies. One of main challenges is the selection and fusion of appropriate detectors, which considers not only semantics but also the reliability of detectors, observability and diversity of detectors in target video domains. In this paper, we present a novel fusion technique which considers different aspects of detectors for query answering. In addition to utilizing detectors for bridging the semantic gap of user queries and multimedia data, we also address the issue of "observability gap" among detectors which could not be directly inferred …

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Using Trusted Computing Technology To Facilitate Security Enforcement In Wireless Sensor Networks, Yanjiang Yang, Robert H. Deng, Feng Bao, Jianying Zhou Oct 2008

Using Trusted Computing Technology To Facilitate Security Enforcement In Wireless Sensor Networks, Yanjiang Yang, Robert H. Deng, Feng Bao, Jianying Zhou

Research Collection School Of Computing and Information Systems

Security enforcement in wireless sensor networks is by no means an easy task, due to the inherent resource-constrained nature of sensor nodes. To facilitate security enforcement, we propose to incorporate more powerful high-end Security Enforcement Facilitators (SEFs) into wireless sensor networks. In particular, the SEFs are equipped with TCG-compliant Trusted Platform Modules (TPMs) to protect cryptographic secrets, perform authenticated booting and attest their platform state to a remote base station.As such, the SEFs act as online trusted third parties toeffectively monitor the states of sensor nodes, help in keymanagement, simplify secure routing, and facilitate accesscontrol.

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Output Regularized Metric Learning With Side Information, Wei Liu, Steven C. H. Hoi, Jianzhuang Liu Oct 2008

Output Regularized Metric Learning With Side Information, Wei Liu, Steven C. H. Hoi, Jianzhuang Liu

Research Collection School Of Computing and Information Systems

Distance metric learning has been widely investigated in machine learning and information retrieval. In this paper, we study a particular content-based image retrieval application of learning distance metrics from historical relevance feedback log data, which leads to a novel scenario called collaborative image retrieval. The log data provide the side information expressed as relevance judgements between image pairs. Exploiting the side information as well as inherent neighborhood structures among examples, we design a convex regularizer upon which a novel distance metric learning approach, named output regularized metric learning, is presented to tackle collaborative image retrieval. Different from previous distance metric …

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