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Research Collection School Of Computing and Information Systems

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Articles 5461 - 5490 of 6891

Full-Text Articles in Physical Sciences and Mathematics

Context Modeling For Ranking And Tagging Bursty Features In Text Streams, Xin Zhao, Jing Jiang, Jing He, Xiaoming Li, Hongfei Yan, Dongdong Shan Oct 2010

Context Modeling For Ranking And Tagging Bursty Features In Text Streams, Xin Zhao, Jing Jiang, Jing He, Xiaoming Li, Hongfei Yan, Dongdong Shan

Research Collection School Of Computing and Information Systems

Bursty features in text streams are very useful in many text mining applications. Most existing studies detect bursty features based purely on term frequency changes without taking into account the semantic contexts of terms, and as a result the detected bursty features may not always be interesting or easy to interpret. In this paper we propose to model the contexts of bursty features using a language modeling approach. We then propose a novel topic diversity-based metric using the context models to find newsworthy bursty features. We also propose to use the context models to automatically assign meaningful tags to bursty …

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Secureangle: Improving Wireless Security Using Angle-Of-Arrival Information, Jie Xiong, Kyle Jamieson Oct 2010

Secureangle: Improving Wireless Security Using Angle-Of-Arrival Information, Jie Xiong, Kyle Jamieson

Research Collection School Of Computing and Information Systems

Wireless networks play an important role in our everyday lives, at the workplace and at home. However, they are also relatively vulnerable: physically located off site, attackers can circumvent wireless security protocols such as WEP, WPA, and even to some extent WPA2, presenting a security risk to the entire network. To address this problem, we propose SecureAngle, a system designed to operate alongside existing wireless security protocols, adding defense in depth. SecureAngle leverages multi-antenna APs to profile the directions at which a client's signal arrives, using this angle-of-arrival (AoA) information to construct signatures that uniquely identify each client. We identify …

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Cast2face: Character Identification In Movie With Actor-Character Correspondence, Mengdi Xu, Xiaotong Yuan, Jialie Shen, Shuicheng Yan Oct 2010

Cast2face: Character Identification In Movie With Actor-Character Correspondence, Mengdi Xu, Xiaotong Yuan, Jialie Shen, Shuicheng Yan

Research Collection School Of Computing and Information Systems

We investigate the problem of automatically identifying characters in a movie with the supervision of actor-character name correspondence provided by the movie cast. Our proposed framework, namely Cast2Face, is featured by: (i) we restrict the names to assign within the set of character names in the cast; (ii) for each character, by using the corresponding actor's name as a key word, we retrieve from Google image search a group of face images to form the gallery set; and (iii) the probe face tracks in the movie are then identified as one of the actors by robust multi-task joint sparse representation …

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Finding Unusual Review Patterns Using Unexpected Rules, Nitin Jindal, Bing Liu, Ee Peng Lim Oct 2010

Finding Unusual Review Patterns Using Unexpected Rules, Nitin Jindal, Bing Liu, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In recent years, opinion mining attracted a great deal of research attention. However, limited work has been done on detecting opinion spam (or fake reviews). The problem is analogous to spam in Web search [1, 9 11]. However, review spam is harder to detect because it is very hard, if not impossible, to recognize fake reviews by manually reading them [2]. This paper deals with a restricted problem, i.e., identifying unusual review patterns which can represent suspicious behaviors of reviewers. We formulate the problem as finding unexpected rules. The technique is domain independent. Using the technique, we analyzed an Amazon.com …

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Jointly Modeling Aspects And Opinions With A Maxent-Lda Hybrid, Xin Zhao, Jing Jiang, Hongfei Yan, Xiaoming Li Oct 2010

Jointly Modeling Aspects And Opinions With A Maxent-Lda Hybrid, Xin Zhao, Jing Jiang, Hongfei Yan, Xiaoming Li

Research Collection School Of Computing and Information Systems

Discovering and summarizing opinions from online reviews is an important and challenging task. A commonly-adopted framework generates structured review summaries with aspects and opinions. Recently topic models have been used to identify meaningful review aspects, but existing topic models do not identify aspect-specific opinion words. In this paper, we propose a MaxEnt-LDA hybrid model to jointly discover both aspects and aspect-specific opinion words. We show that with a relatively small amount of training data, our model can effectively identify aspect and opinion words simultaneously. We also demonstrate the domain adaptability of our model.

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Rich Internet Geoweb For Spatial Data Infrastructure, Tin Seong Kam Oct 2010

Rich Internet Geoweb For Spatial Data Infrastructure, Tin Seong Kam

Research Collection School Of Computing and Information Systems

In this information age, more and more public statistical data such as population census, household living, local economy and business establishment are distributed over the internet within the framework of spatial data infrastructure. By and large, these data are organized geographically such as region, province as well as district. Usually, they are published in the form of digital maps over the internet as simple points, lines and polygons markers limited or no analytical function available to transform these data into useful information. To meet the analytical needs of casual public data users, we contribute RIGVAT, a rich internet geospatial visual …

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Mining Interesting Link Formation Rules In Social Networks, Cane Wing-Ki Leung, Ee Peng Lim, David Lo, Jianshu Weng Oct 2010

Mining Interesting Link Formation Rules In Social Networks, Cane Wing-Ki Leung, Ee Peng Lim, David Lo, Jianshu Weng

Research Collection School Of Computing and Information Systems

Link structures are important patterns one looks out for when modeling and analyzing social networks. In this paper, we propose the task of mining interesting Link Formation rules (LF-rules) containing link structures known as Link Formation patterns (LF-patterns). LF-patterns capture various dyadic and/or triadic structures among groups of nodes, while LF-rules capture the formation of a new link from a focal node to another node as a postcondition of existing connections between the two nodes. We devise a novel LF-rule mining algorithm, known as LFR-Miner, based on frequent subgraph mining for our task. In addition to using a support-confidence framework …

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Business Network-Based Value Creation In Electronic Commerce, Robert John Kauffman, Ting Li, Eric Van Heck Oct 2010

Business Network-Based Value Creation In Electronic Commerce, Robert John Kauffman, Ting Li, Eric Van Heck

Research Collection School Of Computing and Information Systems

Information technologies (IT) have affected economic activities within and beyond the boundaries of the firm, changing the face of e-commerce. This article explores the circumstances under which value is created in business networks made possible by IT. Business networks combine the capabilities of multiple firms to produce and deliver products and services that none of them could more economically produce on its own and for which there is demand in the market. We call this business network-based value creation. We apply economic theory to explain the conditions under which business networks will exist and are able to sustain their value-producing …

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Modeling 3d Facial Expressions Using Geometry Videos, Jiazhi Xia, Ying He, Dao T. P. Quynh, Xiaoming Chen, Steven C. H. Hoi Oct 2010

Modeling 3d Facial Expressions Using Geometry Videos, Jiazhi Xia, Ying He, Dao T. P. Quynh, Xiaoming Chen, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

The significant advances in developing high-speed shape acquisition devices make it possible to capture the moving and deforming objects at video speeds. However, due to its complicated nature, it is technically challenging to effectively model and store the captured motion data. In this paper, we present a set of algorithms to construct geometry videos for 3D facial expressions, including hole filling, geodesic-based face segmentation, and expression-invariant parametrization. Our algorithms are efficient and robust, and can guarantee the exact correspondence of the salient features (eyes, mouth and nose). Geometry video naturally bridges the 3D motion data and 2D video, and provides …

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Trajectory-Based Visualization Of Web Video Topics, Juan Cao, Chong-Wah Ngo, Yong-Dong Zhang, Dong-Ming Zhang, Liang Ma Oct 2010

Trajectory-Based Visualization Of Web Video Topics, Juan Cao, Chong-Wah Ngo, Yong-Dong Zhang, Dong-Ming Zhang, Liang Ma

Research Collection School Of Computing and Information Systems

While there have been research efforts in organizing largescale web videos into topics, efficient browsing of web video topics remains a challenging problem not yet addressed. The related issues include how to efficiently browse and track the evolution of topics and eventually locate the videos of interest. In this paper, we introduce a novel interface for visualizing video topics as evolution trajectories. The trajectory visualization is capable of highlighting milestone events and depicting the topical hotness over time. The interface also allows multi-level browsing from topics to events and to videos, resulting in search exploration could be more efficiently conducted …

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Scenario-Based And Value-Based Specification Mining: Better Together, David Lo, Shahar Maoz Sep 2010

Scenario-Based And Value-Based Specification Mining: Better Together, David Lo, Shahar Maoz

Research Collection School Of Computing and Information Systems

Specification mining takes execution traces as input and extracts likely program invariants, which can be used for comprehension, verification, and evolution related tasks. In this work we integrate scenario-based specification mining, which uses data-mining algorithms to suggest ordering constraints in the form of live sequence charts, an inter-object, visual, modal, scenario-based specification language, with mining of value-based invariants, which detects likely invariants holding at specific program points. The key to the integration is a technique we call scenario-based slicing, running on top of the mining algorithms to distinguish the scenario-specific invariants from the general ones. The resulting suggested specifications are …

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Do Online Reviews Reflect A Product’S True Perceived Quality? An Investigation Of Online Movie Reviews Across Cultures, Noi Sian Koh, Nan Hu, Eric K. Clemons Sep 2010

Do Online Reviews Reflect A Product’S True Perceived Quality? An Investigation Of Online Movie Reviews Across Cultures, Noi Sian Koh, Nan Hu, Eric K. Clemons

Research Collection School Of Computing and Information Systems

This paper investigates when the reported average of online ratings matches the perceived average assessment of the population as a whole, including the average assessments of both raters and non-raters. We apply behavioral theory to capture intentions in rating online movie reviews in two dissimilar countries – China and the United States. We argue that consumers’ rating behaviors are affected by cultural influences and that they are influenced in predictable ways. Based on data collected from IMDB.com and Douban.com, we found significant differences across raters from these two different cultures. Additionally, we examined how cultural elements influence rating behavior for …

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Shortest Path Computation On Air Indexes, Georgios Kellaris, Kyriakos Mouratidis Sep 2010

Shortest Path Computation On Air Indexes, Georgios Kellaris, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

Shortest path computation is one of the most common queries in location-based services that involve transportation net- works. Motivated by scalability challenges faced in the mo- bile network industry, we propose adopting the wireless broad- cast model for such location-dependent applications. In this model the data are continuously transmitted on the air, while clients listen to the broadcast and process their queries locally. Although spatial problems have been considered in this environment, there exists no study on shortest path queries in road networks. We develop the rst framework to compute shortest paths on the air, and demonstrate the practicality and …

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Developing Model Checkers Using Pat, Yang Liu, Jun Sun, Jin Song Dong Sep 2010

Developing Model Checkers Using Pat, Yang Liu, Jun Sun, Jin Song Dong

Research Collection School Of Computing and Information Systems

During the last two decades, model checking has emerged as an effective system analysis technique complementary to simulation and testing. Many model checking algorithms and state space reduction techniques have been proposed. Although it is desirable to have dedicated model checkers for every language (or application domain), implementing one with effective reduction techniques is rather challenging. In this work, we present a generic and extensible framework PAT, which facilitates users to build customized model checkers. PAT provides a library of state-of-art model checking algorithms as well as support for customizing language syntax, semantics, state space reduction techniques, graphic user interfaces, …

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Diract: Agent-Based Interactive Storytelling, Yundong Cai, Zhiqi Shen, Chunyan Miao, Ah-Hwee Tan Sep 2010

Diract: Agent-Based Interactive Storytelling, Yundong Cai, Zhiqi Shen, Chunyan Miao, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

A lot of researches haven been done on the interactive storytelling authoring , e.g. by a director agent, or by interactions among a number of character agents. However, it is still difficult to construct the interactive storytelling for novice users, due to a need of various agents development and complex communication among the agents. We propose an agent-based interactive storytelling architecture, namely DIRACT (short of “Direct and Act”). It is composed of numerous atomic DIRACT agents, which are goal oriented and use an unified communication protocol. By removing the difference between the director and character, each DIRACT agent can either …

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Context-Aware Query Recommendations, Alexandros Ntoulas, Heasoo Hwang, Lise Getoor, Stelios Paparizos, Hady Wirawan Lauw Sep 2010

Context-Aware Query Recommendations, Alexandros Ntoulas, Heasoo Hwang, Lise Getoor, Stelios Paparizos, Hady Wirawan Lauw

Research Collection School Of Computing and Information Systems

Described is a search-related technology in which context information regarding a user's prior search actions is used in making query recommendations for a current user action, such as a query or click. To determine whether each set or subset of context information is relevant to the user action, data obtained from a query log is evaluated. More particularly, a query transition (query-query) graph and a query click (query-URL) graph are extracted from the query log; vectors are computed for the current action and each context/sub-context and evaluated against vectors in the graphs to determine current action-to-context similarity. Also described is …

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A Biologically-Inspired Cognitive Agent Model Integrating Declarative Knowledge And Reinforcement Learning, Ah-Hwee Tan, Gee-Wah Ng Sep 2010

A Biologically-Inspired Cognitive Agent Model Integrating Declarative Knowledge And Reinforcement Learning, Ah-Hwee Tan, Gee-Wah Ng

Research Collection School Of Computing and Information Systems

The paper proposes a biologically-inspired cognitive agent model, known as FALCON-X, based on an integration of the Adaptive Control of Thought (ACT-R) architecture and a class of self-organizing neural networks called fusion Adaptive Resonance Theory (fusion ART). By replacing the production system of ACT-R by a fusion ART model, FALCON-X integrates high-level deliberative cognitive behaviors and real-time learning abilities, based on biologically plausible neural pathways. We illustrate how FALCON-X, consisting of a core inference area interacting with the associated intentional, declarative, perceptual, motor and critic memory modules, can be used to build virtual robots for battles in a simulated RoboCode …

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On Challenges In Evaluating Malware Clustering, Peng Li, Limin Liu, Debin Gao, Michael K Reiter Sep 2010

On Challenges In Evaluating Malware Clustering, Peng Li, Limin Liu, Debin Gao, Michael K Reiter

Research Collection School Of Computing and Information Systems

Malware clustering and classification are important tools that enable analysts to prioritize their malware analysis efforts. The recent emergence of fully automated methods for malware clustering and classification that report high accuracy suggests that this problem may largely be solved. In this paper, we report the results of our attempt to confirm our conjecture that the method of selecting ground-truth data in prior evaluations biases their results toward high accuracy. To examine this conjecture, we apply clustering algorithms from a different domain (plagiarism detection), first to the dataset used in a prior work's evaluation and then to a wholly new …

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Matching Dependence-Related Queries In The System Dependence Graph., Xiaoyin Wang, David Lo, Jiefeng Cheng, Lu Zhang, Hong Mei, Jeffrey Xu Yu Sep 2010

Matching Dependence-Related Queries In The System Dependence Graph., Xiaoyin Wang, David Lo, Jiefeng Cheng, Lu Zhang, Hong Mei, Jeffrey Xu Yu

Research Collection School Of Computing and Information Systems

In software maintenance and evolution, it is common that developers want to apply a change to a number of similar places. Due to the size and complexity of the code base, it is challenging for developers to locate all the places that need the change. A main challenge in locating the places that need the change is that, these places share certain common dependence conditions but existing code searching techniques can hardly handle dependence relations satisfactorily. In this paper, we propose a technique that enables developers to make queries involving dependence conditions and textual conditions on the system dependence graph …

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Comprehensive Evaluation Of Association Measures For Fault Localization, Lucia Lucia, David Lo, Lingxiao Jiang, Aditya Budi Sep 2010

Comprehensive Evaluation Of Association Measures For Fault Localization, Lucia Lucia, David Lo, Lingxiao Jiang, Aditya Budi

Research Collection School Of Computing and Information Systems

In statistics and data mining communities, there have been many measures proposed to gauge the strength of association between two variables of interest, such as odds ratio, confidence, Yule-Y, Yule-Q, Kappa, and gini index. These association measures have been used in various domains, for example, to evaluate whether a particular medical practice is associated positively to a cure of a disease or whether a particular marketing strategy is associated positively to an increase in revenue, etc. This paper models the problem of locating faults as association between the execution or non-execution of particular program elements with failures. There have been …

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A New Framework For Rfid Privacy, Robert H. Deng, Yingjiu Li, Moti Yung, Yunlei Zhao Sep 2010

A New Framework For Rfid Privacy, Robert H. Deng, Yingjiu Li, Moti Yung, Yunlei Zhao

Research Collection School Of Computing and Information Systems

Formal RFID security and privacy frameworks are fundamental to the design and analysis of robust RFID systems. In this paper, we develop a new definitional framework for RFID privacy in a rigorous and precise manner. Our framework is based on a zero-knowledge (ZK) formulation [8,6] and incorporates the notions of adaptive completeness and mutual authentication. We provide meticulous justification of the new framework and contrast it with existing ones in the literature. In particular, we prove that our framework is strictly stronger than the ind-privacy model of [18], which answers an open question posed in [18] for developing stronger RFID …

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A Hoare Calculus For Graph Programs, Christopher M. Poskitt, Detlef Plump Sep 2010

A Hoare Calculus For Graph Programs, Christopher M. Poskitt, Detlef Plump

Research Collection School Of Computing and Information Systems

We present Hoare-style axiom schemata and inference rules for verifying the partial correctness of programs in the graph programming language GP. The pre- and postconditions of this calculus are the nested conditions of Habel, Pennemann and Rensink, extended with expressions for labels in order to deal with GP’s conditional rule schemata and infinite label alphabet. We show that the proof rules are sound with respect to GP’s operational semantics.

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Event Study Method For Validating Agent-Based Trading Simulations, Shih-Fen Cheng Sep 2010

Event Study Method For Validating Agent-Based Trading Simulations, Shih-Fen Cheng

Research Collection School Of Computing and Information Systems

In this paper, we introduce how one can validate an event-centric trading simulation platform that is built with multi-agent technology. The issue of validation is extremely important for agent-based simulations, but unfortunately, so far there is no one universal method that would work in all domains. The primary contribution of this paper is a novel combination of event-centric simulation design and event study approach for market dynamics generation and validation. In our event-centric design, the simulation is progressed by announcing news events that affect market prices. Upon receiving these events, event-aware software agents would adjust their views on the market …

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Embellishing Text Search Queries To Protect User Privacy, Hwee Hwa Pang, Xuhua Ding, Xiaokui Xiao Sep 2010

Embellishing Text Search Queries To Protect User Privacy, Hwee Hwa Pang, Xuhua Ding, Xiaokui Xiao

Research Collection School Of Computing and Information Systems

Users of text search engines are increasingly wary that their activities may disclose confidential information about their business or personal profiles. It would be desirable for a search engine to perform document retrieval for users while protecting their intent. In this paper, we identify the privacy risks arising from semantically related search terms within a query, and from recurring highspecificity query terms in a search session. To counter the risks, we propose a solution for a similarity text retrieval system to offer anonymity and plausible deniability for the query terms, and hence the user intent, without degrading the system’s precision-recall …

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Pseudonym-Based Rfid Discovery Service To Mitigate Unauthorized Tracking In Supply Chain Management, Qiang Yan, Robert H. Deng, Zheng Yan, Yingjiu Li, Tieyan Li Sep 2010

Pseudonym-Based Rfid Discovery Service To Mitigate Unauthorized Tracking In Supply Chain Management, Qiang Yan, Robert H. Deng, Zheng Yan, Yingjiu Li, Tieyan Li

Research Collection School Of Computing and Information Systems

Unauthorized tracking of RFID tagged assets at the system level, where an adversary tracks movement of RFID tagged assets by eavesdropping network messages or compromising date center servers, has not been well recognized in prior research. Compared to the traditional unauthorized tracking by clandestine scanning at the physical level, unauthorized tracking at the system level could be even more harmful as the adversary is able to obtain tracking information on a global scale and without physical presence. This paper analyzes the threat of unauthorized tracking by a semi-trusted RFID Discovery Service which maintains a database of RFID tag location records …

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An Automated Approach For Finding Variable-Constant Pairing Bugs, Julia Lawall, David Lo Sep 2010

An Automated Approach For Finding Variable-Constant Pairing Bugs, Julia Lawall, David Lo

Research Collection School Of Computing and Information Systems

Named constants are used heavily in operating systems code, both as internal flags and in interactions with devices. Decision making within an operating system thus critically depends on the correct usage of these values. Nevertheless, compilers for the languages typically used in implementing operating systems provide little support for checking the usage of named constants. This affects correctness, when a constant is used in a context where its value is meaningless, and software maintenance, when a constant has the right value for its usage context but the wrong name. We propose a hybrid program-analysis and data-mining based approach to identify …

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P2pdoctagger: Content Management Through Automated P2p Collaborative Tagging, Hock Hee Ang, Vivekanand Gopalkrishnan, Wee Keong Ng, Steven C. H. Hoi Sep 2010

P2pdoctagger: Content Management Through Automated P2p Collaborative Tagging, Hock Hee Ang, Vivekanand Gopalkrishnan, Wee Keong Ng, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

As the amount of user generated content grows, personal information management has become a challenging problem. Several information management approaches, such as desktop search, document organization and (collaborative) document tagging have been proposed to address this, however they are either inappropriate or inefficient. Automated collaborative document tagging approaches mitigate the problems of manual tagging, but they are usually based on centralized settings which are plagued by problems such as scalability, privacy, etc. To resolve these issues, we present P2PDocTagger, an automated and distributed document tagging system based on classification in P2P networks. P2P-DocTagger minimizes the efforts of individual peers and …

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Team Performance Prediction In Massively Multiplayer Online Role-Playing Games (Mmorpgs), Kyong Jin Shim, Jaideep Srivastava Aug 2010

Team Performance Prediction In Massively Multiplayer Online Role-Playing Games (Mmorpgs), Kyong Jin Shim, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

In this study, we propose a comprehensive performance management tool for measuring and reporting operational activities of teams. This study uses performance data of game players and teams in EverQuest II, a popular MMORPG developed by Sony Online Entertainment, to build performance prediction models for task performing teams. The prediction models provide a projection of task performing team's future performance based on the past performance patterns of participating players on the team as well as team characteristics. While the existing game system lacks the ability to predict team-level performance, the prediction models proposed in this study are expected to be …

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An Efficient Signcryption Scheme With Key Privacy And Its Extension To Ring Signcryption, Chung Ki Li, Guomin Yang, Duncan S. Wong, Xiaotie Deng, Sherman S. M. Chow Aug 2010

An Efficient Signcryption Scheme With Key Privacy And Its Extension To Ring Signcryption, Chung Ki Li, Guomin Yang, Duncan S. Wong, Xiaotie Deng, Sherman S. M. Chow

Research Collection School Of Computing and Information Systems

In Information Processing Letters (2006), Tan pointed out that the anonymous signcryption scheme proposed by Yang, Wong and Deng (YWD) in ISC 2005 provides neither confidentiality nor anonymity. However, no discussion has been made on how a secure scheme can be made and there is no secure scheme available to date. In this paper, we propose a modification of YWD scheme which resolves the security issues of the original scheme without sacrificing its high efficiency and simple design. Indeed, we show that our scheme achieves confidentiality, existential unforgeability and anonymity with more precise reduction bounds. We also give a variation …

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Automatic Generation Of Semantic Fields For Annotating Web Images, Gang Wang, Tat Seng Chua, Chong-Wah Ngo, Yong Cheng Wang Aug 2010

Automatic Generation Of Semantic Fields For Annotating Web Images, Gang Wang, Tat Seng Chua, Chong-Wah Ngo, Yong Cheng Wang

Research Collection School Of Computing and Information Systems

The overwhelming amounts of multimedia contents have triggered the need for automatically detecting the semantic concepts within the media contents. With the development of photo sharing websites such as Flickr, we are able to obtain millions of images with usersupplied tags. However, user tags tend to be noisy, ambiguous and incomplete. In order to improve the quality of tags to annotate web images, we propose an approach to build Semantic Fields for annotating the web images. The main idea is that the images are more likely to be relevant to a given concept, if several tags to the image belong …

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