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Seemon: Scalable And Energy-Efficient Context Monitoring Framework For Sensor-Rich Mobile Environments, Seungwoo Kang, Jinwon Lee, Hyukjae Jang, Hyonik Lee, Youngki Lee, Souneil Park, Taiwoo Park, Junehwa Song Jun 2008

Seemon: Scalable And Energy-Efficient Context Monitoring Framework For Sensor-Rich Mobile Environments, Seungwoo Kang, Jinwon Lee, Hyukjae Jang, Hyonik Lee, Youngki Lee, Souneil Park, Taiwoo Park, Junehwa Song

Research Collection School Of Computing and Information Systems

Proactively providing services to mobile individuals is essential for emerging ubiquitous applications. The major challenge in providing users with proactive services lies in continuously monitoring their contexts based on numerous sensors. The context monitoring with rich sensors imposes heavy workloads on mobile devices with limited computing and battery power. We present SeeMon, a scalable and energy-efficient context monitoring framework for sensor-rich, resource-limited mobile environments. Running on a personal mobile device, SeeMon effectively performs context monitoring involving numerous sensors and applications. On top of SeeMon, multiple applications on the device can proactively understand users' contexts and react appropriately. This paper proposes …


Semi-Supervised Svm Batch Mode Active Learning For Image Retrieval, Steven Hoi, Rong Jin, Jianke Zhu, Michael R. Lyu Jun 2008

Semi-Supervised Svm Batch Mode Active Learning For Image Retrieval, Steven Hoi, Rong Jin, Jianke Zhu, Michael R. Lyu

Research Collection School Of Computing and Information Systems

Active learning has been shown as a key technique for improving content-based image retrieval (CBIR) performance. Among various methods, support vector machine (SVM) active learning is popular for its application to relevance feedback in CBIR. However, the regular SVM active learning has two main drawbacks when used for relevance feedback. First, SVM often suffers from learning with a small number of labeled examples, which is the case in relevance feedback. Second, SVM active learning usually does not take into account the redundancy among examples, and therefore could select multiple examples in relevance feedback that are similar (or even identical) to …


Gaussian Inference In Ar(1) Time Series With Or Without A Unit Root, Peter C. B. Phillips, Chirok Han Jun 2008

Gaussian Inference In Ar(1) Time Series With Or Without A Unit Root, Peter C. B. Phillips, Chirok Han

Research Collection School Of Economics

This paper introduces a simple first-difference-based approach to estimation and inference for the AR(1) model. The estimates have virtually no finite-sample bias and are not sensitive to initial conditions, and the approach has the unusual advantage that a Gaussian central limit theory applies and is continuous as the autoregressive coefficient passes through unity with a uniform rate of convergence. En route, a useful central limit theorem (CLT) for sample covariances of linear processes is given, following Phillips and Solo (1992, Annals of Statistics, 20, 971–1001). The approach also has useful extensions to dynamic panels.


Predicting Trusts Among Users Of Online Communities: An Epinions Case Study, Haifeng Liu, Ee Peng Lim, Hady W. Lauw, Minh-Tam Le, Aixin Sun, Jaideep Srivastava, Young Ae Kim Jun 2008

Predicting Trusts Among Users Of Online Communities: An Epinions Case Study, Haifeng Liu, Ee Peng Lim, Hady W. Lauw, Minh-Tam Le, Aixin Sun, Jaideep Srivastava, Young Ae Kim

Research Collection School Of Computing and Information Systems

Trust between a pair of users is an important piece of information for users in an online community (such as electronic commerce websites and product review websites) where users may rely on trust information to make decisions. In this paper, we address the problem of predicting whether a user trusts another user. Most prior work infers unknown trust ratings from known trust ratings. The effectiveness of this approach depends on the connectivity of the known web of trust and can be quite poor when the connectivity is very sparse which is often the case in an online community. In this …


Electric Elves: What Went Wrong And Why, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Reddy Varakantham, Paul Scerri, David V. Pynadath Jun 2008

Electric Elves: What Went Wrong And Why, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Reddy Varakantham, Paul Scerri, David V. Pynadath

Research Collection School Of Computing and Information Systems

Software personal assistants continue to be a topic of significant research interest. This article outlines some of the important lessons learned from a successfully-deployed team of personal assistant agents (Electric Elves) in an office environment. In the Electric Elves project, a team of almost a dozen personal assistant agents were continually active for seven months. Each elf (agent) represented one person and assisted in daily activities in an actual office environment. This project led to several important observations about privacy, adjustable autonomy, and social norms in office environments. In addition to outlining some of the key lessons learned we outline …


Capacity Constrained Assignment In Spatial Databases, Hou U Leong, Man Lung Yiu, Kyriakos Mouratidis, Nikos Mamoulis Jun 2008

Capacity Constrained Assignment In Spatial Databases, Hou U Leong, Man Lung Yiu, Kyriakos Mouratidis, Nikos Mamoulis

Research Collection School Of Computing and Information Systems

Given a point set P of customers (e.g., WiFi receivers) and a point set Q of service providers (e.g., wireless access points), where each q 2 Q has a capacity q.k, the capacity constrained assignment (CCA) is a matching M Q × P such that (i) each point q 2 Q (p 2 P) appears at most k times (at most nce) in M, (ii) the size of M is maximized (i.e., it comprises min{|P|,P q2Q q.k} pairs), and (iii) the total assignment cost (i.e., the sum of Euclidean distances within all pairs) is minimized. Thus, the CCA problem is …


Advances And Challenges For Scalable Provenance In Stream Processing Systems, Archan Misra, Marion Blount, Anastasios Kementsietsidis, Daby Sow, Min Wang Jun 2008

Advances And Challenges For Scalable Provenance In Stream Processing Systems, Archan Misra, Marion Blount, Anastasios Kementsietsidis, Daby Sow, Min Wang

Research Collection School Of Computing and Information Systems

While data provenance is a well-studied topic in both database and workflow systems, its support within stream processing systems presents a new set of challenges. Part of the challenge is the high stream event rate and the low processing latency requirements imposed by many streaming applications. For example, emerging streaming applications in healthcare or finance call for data provenance, as illustrated in the Century stream processing infrastructure that we are building for supporting online healthcare analytics. At anytime, given an output data element (e.g., a medical alert) generated by Century, the system must be able to retrieve the input and …


Work Dispersion, Process-Based Learning And Offshore Software Development Performance, Narayanasamy Ramasubbu, Sunil Mithas, M. S. Krishnan, Chris Kemerer Jun 2008

Work Dispersion, Process-Based Learning And Offshore Software Development Performance, Narayanasamy Ramasubbu, Sunil Mithas, M. S. Krishnan, Chris Kemerer

Research Collection School Of Computing and Information Systems

In this paper we develop a learning-mediated model of offshore software project productivity and quality to examine whether widely adopted structured software processes are effective in mitigating the negative effects of work dispersion in offshore software development. We explicate how the key process areas of the capability maturity model (CMM) can be utilized as a platform to launch learning routines in offshore software development and thereby explain why some offshore software development process improvement initiatives are more effective than others. We validate our learning-mediated model of offshore software project performance by utilizing data collected from 42 offshore software projects of …


Semi-Supervised Distance Metric Learning For Collaborative Image Retrieval, Steven Hoi, Wei Liu, Shih-Fu Chang Jun 2008

Semi-Supervised Distance Metric Learning For Collaborative Image Retrieval, Steven Hoi, Wei Liu, Shih-Fu Chang

Research Collection School Of Computing and Information Systems

Typical content-based image retrieval (CBIR) solutions with regular Euclidean metric usually cannot achieve satisfactory performance due to the semantic gap challenge. Hence, relevance feedback has been adopted as a promising approach to improve the search performance. In this paper, we propose a novel idea of learning with historical relevance feedback log data, and adopt a new paradigm called “Collaborative Image Retrieval” (CIR). To effectively explore the log data, we propose a novel semi-supervised distance metric learning technique, called “Laplacian Regularized Metric Learning” (LRML), for learning robust distance metrics for CIR. Different from previous methods, the proposed LRML method integrates both …


Platform Competition In Digital Systems: Architectural Control And Value Migration, C. Jason Woodard May 2008

Platform Competition In Digital Systems: Architectural Control And Value Migration, C. Jason Woodard

Research Collection School Of Computing and Information Systems

Digital systems give rise to complex layered architectures in which products at one layer serve as platforms for applications and services in adjacent layers. Platform owners face a difficult balancing act. On one hand, they need to make their platforms attractive to potential complementors by mitigating the threat of architectural lock-in. On the other hand, platform owners must be careful not to give away too much too soon, or risk being unable to recoup their own investments. This paper presents an agent-based model that explores this tension at both the firm and industry levels. Computational experiments show that boundedly rational …


Stress Test, M. Thulasidas May 2008

Stress Test, M. Thulasidas

Research Collection School Of Computing and Information Systems

Ultimately, the risk factors that create stress in professional life do not generate any reward


A Verification System For Timed Interval Calculus, Chunqing Chen, Jin Song Dong, Jun Sun May 2008

A Verification System For Timed Interval Calculus, Chunqing Chen, Jin Song Dong, Jun Sun

Research Collection School Of Computing and Information Systems

Timed Interval Calculus (TIC) is a highly expressive set-based notation for specifying and reasoning about embedded real-time systems. However, it lacks mechanical proving support, as its verification usually involves infinite time intervals and continuous dynamics. In this paper, we develop a system based on a generic theorem prover, Prototype Verification System (PVS), to assist formal verification of TIC at a high grade of automation. TIC semantics has been constructed by the PVS typed higher-order logic. Based on the encoding, we have checked all TIC reasoning rules and discovered subtle flaws. A translator has been implemented in Java to automatically transform …


Measuring Soa Success, J. Erickson, Keng Siau May 2008

Measuring Soa Success, J. Erickson, Keng Siau

Research Collection School Of Computing and Information Systems

Service-oriented architecture (SOA), web services, and service-oriented computing (SOC) have become prominent topics in the business world. Many companies are either implementing, considering, or have already implemented SOA projects, web services initiatives, or SOC adoption. A critical question for organizations is how to measure SOA success. Is return on investment (ROI) a suitable metric for evaluating SOA projects? What about intangible factors such as comparative advantage or competitive necessity? Additionally, considerations like agility, nimbleness, and responsiveness play a significant role. This research investigates various factors for measuring project success and employs a Delphi study to gather insights from a panel …


A Dynamic Trust Management Scheme To Mitigate Malware Proliferation In P2p Networks, Xuhua Ding, Wei Yu, Ying Pan May 2008

A Dynamic Trust Management Scheme To Mitigate Malware Proliferation In P2p Networks, Xuhua Ding, Wei Yu, Ying Pan

Research Collection School Of Computing and Information Systems

The surge of peer-to-peer (P2P) networks consisting of thousands of of hosts makes them a breeding ground for malware proliferation. Although some existing studies have shown that malware proliferation can pose significant threats to P2P networks, defending against such an attack is largely an open problem. This paper aims to develop the countermeasure that can effectively mitigate the malware proliferation while preserving P2P networks' performance. To this end, we propose a dynamic trust management scheme based upon localized trust evaluation and alert propagation which prevents innocent peers from downloading files from infected peers. Our analysis and experimental results show that …


Reaping The Rewards Of Diversity: The Role Of Identity Integration, Chi-Ying Cheng, Melissa Sanders, Jeffrey Sanchez-Burks, Kristine Molina, Fiona Lee, Emily Darling, Yu Zhao May 2008

Reaping The Rewards Of Diversity: The Role Of Identity Integration, Chi-Ying Cheng, Melissa Sanders, Jeffrey Sanchez-Burks, Kristine Molina, Fiona Lee, Emily Darling, Yu Zhao

Research Collection School of Social Sciences

How does diversity affect individuals and the groups in which they are embedded? This article examines this question using recent theory and research on Identity Integration (II). II refers to an individual's perceptions about whether two distinct social identities, or social groups to which individuals belong, are viewed as compatible (high II) or not (low II). A review of extant research suggests that individuals with high II are better at simultaneously accessing multiple identities and identity-related knowledge and have improved well-being and social outcomes. Expanding on this work, we argue that individuals who have higher II, and social collectives that …


Architectural Control Points, C. Jason Woodard May 2008

Architectural Control Points, C. Jason Woodard

Research Collection School Of Computing and Information Systems

System designers and technology strategists have long recognized the concept of an architectural control point as a way to identify parts of a system that have particular strategic importance. Despite the vast body of work on system architecture in the engineering design literature, however, few authors have attempted to define architectural control points or study them systematically. Moreover, some industry participants have questioned whether architectural control is still a valuable or achievable goal in an era of increasingly open standards. This paper offers tentative definitions of architectural control, architectural control points, and architectural strategy. In a longer version of the …


Skilled And Unskilled Wages In A Globlizing World, 1968-1998, Davin Chor May 2008

Skilled And Unskilled Wages In A Globlizing World, 1968-1998, Davin Chor

Research Collection School Of Economics

This paper constructs a data set on purchasing-power-parity (PPP) adjusted skilled and unskilled wages in 139 countries for the period 1968-1998, based on the International La- bor Organization's (ILO) annual October Inquiry and the Freeman and Oostendorp (2000) Occupational Wages Around the World (OWW) le. It nds strong evidence for the ex- istence of well-integrated markets for skilled and unskilled labor, justifying the approach of constructing a skilled wage series and an unskilled wage series. Several signi cant re- sults emerged from an analysis of a representative subset of 67 countries which provided unbroken coverage for 1970-1994: (i) there is …


Scalable Detection Of Semantic Clones, Mark Gabel, Lingxiao Jiang, Zhendong Su May 2008

Scalable Detection Of Semantic Clones, Mark Gabel, Lingxiao Jiang, Zhendong Su

Research Collection School Of Computing and Information Systems

Several techniques have been developed for identifying similar code fragments in programs. These similar fragments, referred to as code clones, can be used to identify redundant code, locate bugs, or gain insight into program design. Existing scalable approaches to clone detection are limited to finding program fragments that are similar only in their contiguous syntax. Other, semantics-based approaches are more resilient to differences in syntax, such as reordered statements, related statements interleaved with other unrelated statements, or the use of semantically equivalent control structures. However, none of these techniques have scaled to real world code bases. These approaches capture semantic …


Verifying Completeness Of Relational Query Answers From Online Servers, Hwee Hwa Pang, Kian-Lee Tan May 2008

Verifying Completeness Of Relational Query Answers From Online Servers, Hwee Hwa Pang, Kian-Lee Tan

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 servers over extended periods of time. A breached server that is not detected in time may return incorrect query answers to users. In this article, we introduce authentication schemes for users to verify that their query answers from an online server are complete (i.e., no qualifying tuples are omitted) and authentic (i.e., all the result values are legitimate). We introduce a scheme that supports range selection, projection as well as primary key-foreign key join queries on relational databases. We also …


A Scalable Approach To Multi-Style Architectural Modeling And Verification, Stephen Wong, Jing Sun, Ian Warren, Jun Sun Apr 2008

A Scalable Approach To Multi-Style Architectural Modeling And Verification, Stephen Wong, Jing Sun, Ian Warren, Jun Sun

Research Collection School Of Computing and Information Systems

Software Architecture represents the high level description of a system in terms of components, external properties and communication. Despite its importance in the software engineering process, the lack of formal description and verification support limits the value of developing architectural models. Automated formal engineering methods can provide an effective means to precisely describe and rigorously verify intended structures and behaviors of software systems. In this paper, we present an approach to support the design and verification of software architectural models using the Alloy analyzer. Based on our earlier work, we propose a fundamental library for specifying system structures in terms …


A Formal Model Of Semantic Web Service Ontology (Wsmo) Execution, Hai H. Wang, Nick Gibbins, Terry R. Payne, Ahmed Saleh, Jun Sun Apr 2008

A Formal Model Of Semantic Web Service Ontology (Wsmo) Execution, Hai H. Wang, Nick Gibbins, Terry R. Payne, Ahmed Saleh, Jun Sun

Research Collection School Of Computing and Information Systems

Semantic Web services have been one of the most significant research areas within the semantic Web vision, and have been recognized as a promising technology that exhibits huge commercial potential. Current semantic Web service research focuses on defining models and languages for the semantic markup of all relevant aspects of services, which are accessible through a Web service interface. The Web service modelling ontology (WSMO) is one of the most significant semantic Web service framework proposed to date. To support the standardization and tool support of WSMO, a formal semantics of the language is highly desirable. As there are a …


Measurement And Estimation Of Network Qos Among Peer Xbox 360 Game Players, Youngki Lee, Sharad Agarwal, Chris Butcher, Jitu Padhye Apr 2008

Measurement And Estimation Of Network Qos Among Peer Xbox 360 Game Players, Youngki Lee, Sharad Agarwal, Chris Butcher, Jitu Padhye

Research Collection School Of Computing and Information Systems

The research community has proposed several techniques for estimating the quality of network paths in terms of delay and capacity. However, few techniques have been studied in the context of large deployed applications. Network gaming is an application that is extremely sensitive to network path quality [1,2,3]. Yet, the quality of network paths among players of large, wide-area games and techniques for estimating it have not received much attention from the research community.


E-Government Implementation: A Macro Analysis Of Singapore's E-Government Initiatives, Calvin M.L. Chan, Yi Meng Lau, Shan L. Pan Apr 2008

E-Government Implementation: A Macro Analysis Of Singapore's E-Government Initiatives, Calvin M.L. Chan, Yi Meng Lau, Shan L. Pan

Research Collection School Of Computing and Information Systems

This paper offers a macro perspective of the various activities involved in the implementation of e-government through an interpretive analysis of the various e-government-related initiatives undertaken by the Singapore Government. The analysis lead to the identification of four main components in the implementation of e-government, namely (i) information content, (ii) ICT infrastructure, (iii) e-government infostructure, and (iv) e-government promotion. These four components were then conceptually integrated into the e-Government Implementation Framework. This paper suggests that this framework can either be used as a descriptive tool to organize and coordinate various e-government initiatives, or be used as a prescriptive structure to …


Efficient Optimistic Fair Exchange Secure In The Multi-User Setting And Chosen-Key Model Without Random Oracles, Qiong Huang, Guomin Yang, Duncan S. Wong, Willy Susilo Apr 2008

Efficient Optimistic Fair Exchange Secure In The Multi-User Setting And Chosen-Key Model Without Random Oracles, Qiong Huang, Guomin Yang, Duncan S. Wong, Willy Susilo

Research Collection School Of Computing and Information Systems

Optimistic fair exchange is a kind of protocols to solve the problem of fair exchange between two parties. Almost all the previous work on this topic are provably secure only in the random oracle model. In PKC 2007, Dodis et al. considered optimistic fair exchange in a multi-user setting, and showed that the security of an optimistic fair exchange in a single-user setting may no longer be secure in a multi-user setting. Besides, they also proposed one and reviewed several previous construction paradigms and showed that they are secure in the multi-user setting. However, their proofs are either in the …


Multicultural Experience Enhances Creativity: The When And How, Angela K. Y. Leung, William W. Maddux, Adam D. Galinsky, Chi-Yue Chiu Apr 2008

Multicultural Experience Enhances Creativity: The When And How, Angela K. Y. Leung, William W. Maddux, Adam D. Galinsky, Chi-Yue Chiu

Research Collection School of Social Sciences

Many practices aimed at cultivating multicultural competence in educational and organizational settings (e.g., exchange programs, diversity education in college, diversity management at work) assume that multicultural experience fosters creativity. In line with this assumption, the research reported in this article is the first to empirically demonstrate that exposure to multiple cultures in and of itself can enhance creativity. Overall, the authors found that extensiveness of multicultural experiences was positively related to both creative performance (insight learning, remote association, and idea generation) and creativity-supporting cognitive processes (retrieval of unconventional knowledge, recruitment of ideas from unfamiliar cultures for creative idea expansion). Furthermore, …


Rate-Diversity And Resource-Aware Broadcast And Multicast In Multi-Rate Wireless Mesh Networks, Bao Hua Liu, Chun Tung Chou, Archan Misra, Sanjay Jha Apr 2008

Rate-Diversity And Resource-Aware Broadcast And Multicast In Multi-Rate Wireless Mesh Networks, Bao Hua Liu, Chun Tung Chou, Archan Misra, Sanjay Jha

Research Collection School Of Computing and Information Systems

This paper focuses on the problem of increasing the traffic capacity (volume of admissible traffic) of broadcast and multicast flows in a wireless mesh network (WMN). We study and suggest routing strategies where the process of constructing the forwarding tree considers three distinct features: (a) the ability of individual mesh nodes to perform link-layer broadcasts at multiple rates, (b) the wireless broadcast advantage, whereby a single broadcast transmission covers multiple neighboring receivers and (c) the residual transmission capacity at a WMN node, subject to intereference-based constraints from existing traffic flows in its neighborhood. Our metric of interest is the total …


K-Sketch: A 'Kinetic' Sketch Pad For Novice Animators, Richard C. Davis, Brien Colwell, James A. Landay Apr 2008

K-Sketch: A 'Kinetic' Sketch Pad For Novice Animators, Richard C. Davis, Brien Colwell, James A. Landay

Research Collection School Of Computing and Information Systems

Because most animation tools are complex and timeconsuming to learn and use, most animations today are created by experts. To help novices create a wide range of animations quickly, we have developed a general-purpos informal, 2D animation sketching system called K-Sketch. Field studies investigating the needs of animatorsnd would-be animators helped us collect a library of usage scenarios for our tool. A novel optimization technique enabled us to design an interface that is simultaneously fast, simple, and powerful. The result is a pen-based system that relies on users’ intuitive sense of space and time while still supporting a wide range …


Building A Web Of Trust Without Explicit Trust Ratings, Young Ae Kim, Minh-Tam Le, Hady W. Lauw, Ee Peng Lim, Haifeng Liu, Jaideep Srivastava Apr 2008

Building A Web Of Trust Without Explicit Trust Ratings, Young Ae Kim, Minh-Tam Le, Hady W. Lauw, Ee Peng Lim, Haifeng Liu, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

A satisfactory and robust trust model is gaining importance in addressing information overload, and helping users collect reliable information in online communities. Current research on trust prediction strongly relies on a web of trust, which is directly collected from users based on previous experience. However, the web of trust is not always available in online communities and even though it is available, it is often too sparse to predict the trust value between two unacquainted people with high accuracy. In this paper, we propose a framework to derive degree of trust based on users' expertise and users' affinity for certain …


Validating Multi-Column Schema Matchings By Type, Bing Tian Dai, Nick Koudas, Divesh Srivastava, Anthony K.H. Tung, Suresh Venkatasubramanian Apr 2008

Validating Multi-Column Schema Matchings By Type, Bing Tian Dai, Nick Koudas, Divesh Srivastava, Anthony K.H. Tung, Suresh Venkatasubramanian

Research Collection School Of Computing and Information Systems

Validation of multi-column schema matchings is essential for successful database integration. This task is especially difficult when the databases to be integrated contain little overlapping data, as is often the case in practice (e.g., customer bases of different companies). Based on the intuition that values present in different columns related by a schema matching will have similar "semantic type", and that this can be captured using distributions over values ("statistical types"), we develop a method for validating 1-1 and compositional schema matchings. Our technique is based on three key technical ideas. First, we propose a generic measure for comparing two …


Comp-Ref: A Technique To Guide The Delegation Of Responsibilities To Components In Software Systems, Subhajit Datta, Robert Van Engelen Apr 2008

Comp-Ref: A Technique To Guide The Delegation Of Responsibilities To Components In Software Systems, Subhajit Datta, Robert Van Engelen

Research Collection School Of Computing and Information Systems

In software systems, components collaborate to collectively fulfill requirements. A key concern of software design is the delegation of responsibilities to components such that user needs are most expediently met. This paper presents the COMP-REF technique based on a set of metrics and Linear Programming (LP) to guide the allocation of responsibilities of a system’s components. We define the metrics Aptitude Index, Requirement Set, and Concordance Index to extract some design characteristics and use these metrics in an optimization algorithm. Results from experimental validation of the COMP-REF technique across a range of software systems are reported. We also …