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Articles 5221 - 5250 of 6891

Full-Text Articles in Physical Sciences and Mathematics

Value Relevance Of Blog Visibility, Nan Hu, Ling Liu, Arindam Tripathy, Lee J. Yao Dec 2011

Value Relevance Of Blog Visibility, Nan Hu, Ling Liu, Arindam Tripathy, Lee J. Yao

Research Collection School Of Computing and Information Systems

This study empirically examines the effect of a non-traditional information source, namely a firm's blog visibility on the capital market valuation of firms. After controlling for earnings, book value of equity and other value relevant variables, such as traditional media exposure, R&D spending, and advertising expense, we find a positive association between a firm's blog visibility and its capital market valuation. In addition, we find blog visibility Grange causes trading, not vice versa. Our findings indicate that non-traditional information sources such as blogs help disseminate information and influence consumers' investment decisions by capturing their attention.


Tag-Based Social Image Search With Visual-Text Joint Hypergraph Learning, Yue Gao, Meng Wang, Huanboo Luan, Jialie Shen, Shuicheng Yan, Dacheng Tao Dec 2011

Tag-Based Social Image Search With Visual-Text Joint Hypergraph Learning, Yue Gao, Meng Wang, Huanboo Luan, Jialie Shen, Shuicheng Yan, Dacheng Tao

Research Collection School Of Computing and Information Systems

Tag-based social image search has attracted great interest and how to order the search results based on relevance level is a research problem. Visual content of images and tags have both been investigated. However, existing methods usually employ tags and visual content separately or sequentially to learn the image relevance. This paper proposes a tag-based image search with visual-text joint hypergraph learning. We simultaneously investigate the bag-of-words and bag-of-visual-words representations of images and accomplish the relevance estimation with a hypergraph learning approach. Each textual or visual word generates a hyperedge in the constructed hypergraph. We conduct experiments with a real-world …


Modeling Social Strength In Social Media Community Via Kernel-Based Learning, Jinfeng Zhuang, Tao Mei, Steven C. H. Hoi, Xian-Sheng Hua, Shipeng Li Dec 2011

Modeling Social Strength In Social Media Community Via Kernel-Based Learning, Jinfeng Zhuang, Tao Mei, Steven C. H. Hoi, Xian-Sheng Hua, Shipeng Li

Research Collection School Of Computing and Information Systems

Modeling continuous social strength rather than conventional binary social ties in the social network can lead to a more precise and informative description of social relationship among people. In this paper, we study the problem of social strength modeling (SSM) for the users in a social media community, who are typically associated with diverse form of data. In particular, we take Flickr---the most popular online photo sharing community---as an example, in which users are sharing their experiences through substantial amounts of multimodal contents (e.g., photos, tags, geo-locations, friend lists) and social behaviors (e.g., commenting and joining interest groups). Such heterogeneous …


Towards Textually Describing Complex Video Contents With Audio-Visual Concept Classifiers, Chun Chet Tan, Yu-Gang Jiang, Chong-Wah Ngo Dec 2011

Towards Textually Describing Complex Video Contents With Audio-Visual Concept Classifiers, Chun Chet Tan, Yu-Gang Jiang, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Automatically generating compact textual descriptions of complex video contents has wide applications. With the recent advancements in automatic audio-visual content recognition, in this paper we explore the technical feasibility of the challenging issue of precisely recounting video contents. Based on cutting-edge automatic recognition techniques, we start from classifying a variety of visual and audio concepts in video contents. According to the classification results, we apply simple rule-based methods to generate textual descriptions of video contents. Results are evaluated by conducting carefully designed user studies. We find that the state-of-the-art visual and audio concept classification, although far from perfect, is able …


Cross Media Hyperlinking For Search Topic Browsing, Song Tan, Chong-Wah Ngo, Hung-Khoon Tan, Lei Pang Dec 2011

Cross Media Hyperlinking For Search Topic Browsing, Song Tan, Chong-Wah Ngo, Hung-Khoon Tan, Lei Pang

Research Collection School Of Computing and Information Systems

With the rapid growth of social media, there are plenty of information sources freely available online for use. Nevertheless, how to synchronize and leverage these diverse forms of information for multimedia applications remains a problem yet to be seriously studied. This paper investigates the synchronization of multiple media content in the physical form of hyperlinking them. The ultimate goal is to develop browsing systems that author search results with rich media information mined from various knowledge sources. The authoring enables the vivid visualization and exploration of different information landscapes inherent in search results. Several key techniques are studied in this …


On The Pooling Of Positive Examples With Ontology For Visual Concept Learning, Shiai Zhu, Chong-Wah Ngo, Yu-Gang Jiang Dec 2011

On The Pooling Of Positive Examples With Ontology For Visual Concept Learning, Shiai Zhu, Chong-Wah Ngo, Yu-Gang Jiang

Research Collection School Of Computing and Information Systems

A common obstacle in effective learning of visual concept classifiers is the scarcity of positive training examples due to expensive labeling cost. This paper explores the sampling of weakly tagged web images for concept learning without human assistance. In particular, ontology knowledge is incorporated for semantic pooling of positive examples from ontologically neighboring concepts. This effectively widens the coverage of the positive samples with visually more diversified content, which is important for learning a good concept classifier. We experiment with two learning strategies: aggregate and incremental. The former strategy re-trains a new classifier by combining existing and newly collected examples, …


From Primordial Soup To Platform-Based Competition: Exploring The Emergence Of Products, Systems, And Platforms, C. Jason Woodard, Eric K. Clemons Dec 2011

From Primordial Soup To Platform-Based Competition: Exploring The Emergence Of Products, Systems, And Platforms, C. Jason Woodard, Eric K. Clemons

Research Collection School Of Computing and Information Systems

We use an agent-based NK model to explore the conditions under which standard platforms emerge among competing products. Our findings were inconclusive. We find that the usual Darwinian conditions needed for the emergence of complexity are sufficient to yield a limited reliance upon platforms with a core of common components, simply because evolution causes the population to converge on a set of products that contain combinations that "work well," yielding what we call "coincidental platform emergence." Economies of scale yield more use of common components, or "production platform emergence." Positive participation externalities initially induce the highest degree of platform emergence …


Four-Jet Final State Production In E+E- Collisions At Centre-Of-Mass Energies Of 130 And 136 Gev, D. Buskulic, M. Thulasidas Dec 2011

Four-Jet Final State Production In E+E- Collisions At Centre-Of-Mass Energies Of 130 And 136 Gev, D. Buskulic, M. Thulasidas

Research Collection School Of Computing and Information Systems

The four-jet final state is analyzed to search for hadronic decays of pair-produced heavy particles. The analysis uses the ALEPH data collected at LEP in November 1995 at centre-of-mass energies of 130 and 136 GeV, corresponding to a total integrated luminosity of 5.7 pb1 . An excess of four-jet events is observed with respect to the standard model predictions. In addition, these events exhibit an enhancement in the sum of the two di-jet masses around 105 GeV/c 2 . The properties of these events are studied and compared to the expectations from standard processes and to pair production hypotheses


Context-Based Friend Suggestion In Online Photo-Sharing Community, Ting Yao, Chong-Wah Ngo, Tao Mei Dec 2011

Context-Based Friend Suggestion In Online Photo-Sharing Community, Ting Yao, Chong-Wah Ngo, Tao Mei

Research Collection School Of Computing and Information Systems

With the popularity of social media, web users tend to spend more time than before for sharing their experience and interest in online photo-sharing sites. The wide variety of sharing behaviors generate different metadata which pose new opportunities for the discovery of communities. We propose a new approach, named context-based friend suggestion, to leverage the diverse form of contextual cues for more effective friend suggestion in the social media community. Different from existing approaches, we consider both visual and geographical cues, and develop two user-based similarity measurements, i.e., visual similarity and geo similarity for characterizing user relationship. The problem of …


Automated Removal Of Cross Site Scripting Vulnerabilities In Web Applications, Lwin Khin Shar, Hee Beng Kuan Tan Dec 2011

Automated Removal Of Cross Site Scripting Vulnerabilities In Web Applications, Lwin Khin Shar, Hee Beng Kuan Tan

Research Collection School Of Computing and Information Systems

Context: Cross site scripting (XSS) vulnerability is among the top web application vulnerabilities according to recent surveys. This vulnerability occurs when a web application uses inputs received from users in web pages without properly checking them. This allows an attacker to inject malicious scripts in web pages via such inputs such that the scripts perform malicious actions when a client visits the exploited web pages. Such an attack may cause serious security violations such as account hijacking and cookie theft. Current approaches to mitigate this problem mainly focus on effective detection of XSS vulnerabilities in the programs or prevention of …


Agile Innovation Management, Arcot Desai Narasimhalu Nov 2011

Agile Innovation Management, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

The volume and velocity of innovations are on the increase resulting in increased pressures on every company for attaining, retaining and increasing its market leadership. Many companies need to retool their innovation management processes to address two agility related objectives in order to survive and grow in such a rapidly changing innovation environment. The first objective would be the ability to assemble an innovation team within the shortest possible time. This can only be satisfied by companies that are capable of forming innovation teams rather quickly. The related second objective would be to reduce the I2M (Idea to Market) cycle …


Launching Return-Oriented Programming Attacks Against Randomized Relocatable Executables, Limin Liu, Jin Han, Debin Gao, Jiwu Jing, Daren Zha Nov 2011

Launching Return-Oriented Programming Attacks Against Randomized Relocatable Executables, Limin Liu, Jin Han, Debin Gao, Jiwu Jing, Daren Zha

Research Collection School Of Computing and Information Systems

Since the day it was proposed, return-oriented programming has shown to be an effective and powerful attack technique against the write or execute only (W ⊕ X) protection. However, a general belief in the previous research is, systems deployed with address space randomization where the executables are also randomized at run-time are able to defend against return-oriented programming, as the addresses of all instructions are randomized. In this paper, we show that due to the weakness of current address space randomization technique, there are still ways of launching return-oriented programming attacks against those well-protected systems efficiently. We demonstrate and evaluate …


A Model Checking Framework For Hierarchical Systems., Truong Khanh Nguyen, Jun Sun, Yang Liu, Jin Song Dong Nov 2011

A Model Checking Framework For Hierarchical Systems., Truong Khanh Nguyen, Jun Sun, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

BDD-based symbolic model checking is capable of verifying systems with a large number of states. In this work, we report an extensible framework to facilitate symbolic encoding and checking of hierarchical systems. Firstly, a novel library of symbolic encoding functions for compositional operators (e.g., parallel composition, sequential composition, choice operator, etc.) are developed so that users can apply symbolic model checking techniques to hierarchical systems with little knowledge of symbolic encoding techniques (like BDD or CUDD). Secondly, as the library is language-independent, we build an extensible framework with various symbolic model checking algorithms so that the library can be easily …


Search-Based Fault Localization, Shaowei Wang, David Lo, Lingxiao Jiang, - Lucia, Hoong Chuin Lau Nov 2011

Search-Based Fault Localization, Shaowei Wang, David Lo, Lingxiao Jiang, - Lucia, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Many spectrum-based fault localization measures have been proposed in the literature. However, no single fault localization measure completely outperforms others: a measure which is more accurate in localizing some bugs in some programs is less accurate in localizing other bugs in other programs. This paper proposes to compose existing spectrum-based fault localization measures into an improved measure. We model the composition of various measures as an optimization problem and present a search-based approach to explore the space of many possible compositions and output a heuristically near optimal composite measure. We employ two search-based strategies including genetic algorithm and simulated annealing …


A Pomdp Model For Guiding Taxi Cruising In A Congested Urban City, Lucas Agussurja, Hoong Chuin Lau Nov 2011

A Pomdp Model For Guiding Taxi Cruising In A Congested Urban City, Lucas Agussurja, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We consider a partially observable Markov decision process (POMDP) model for improving a taxi agent cruising decision in a congested urban city. Using real-world data provided by a large taxi company in Singapore as a guide, we derive the state transition function of the POMDP. Specifically, we model the cruising behavior of the drivers as continuous-time Markov chains. We then apply dynamic programming algorithm for finding the optimal policy of the driver agent. Using a simulation, we show that this policy is significantly better than a greedy policy in congested road network.


Exploring Tweets Normalization And Query Time Sensitivity For Twitter Search, Zhongyu Wei, Wei Gao, Lanjun Zhou, Binyang Li, Kam-Fai Wong Nov 2011

Exploring Tweets Normalization And Query Time Sensitivity For Twitter Search, Zhongyu Wei, Wei Gao, Lanjun Zhou, Binyang Li, Kam-Fai Wong

Research Collection School Of Computing and Information Systems

This paper presents our work for the Realtime Adhoc Task of TREC 2011 Microblog Track. Microblog texts like tweets are generally characterized by the inclusion of a large proportion of irregular expressions, such as ill-formed words, which can lead to significant mismatch between query terms and tweets. In addition, Twitter queries are distinguished from Web queries with many unique characteristics, one of which reflects the clearly distinct temporal aspects of Twitter search behavior. In this study, we deal with the first problem by normalizing tweet texts and the second by capturing the temporal characteristics of topic. We divided topics into …


Are There Contagion Effects In Information Technology And Business Process Outsourcing?, Arti Mann, Robert J. Kauffman, Kunsoo Han, Barrie R. Nault Nov 2011

Are There Contagion Effects In Information Technology And Business Process Outsourcing?, Arti Mann, Robert J. Kauffman, Kunsoo Han, Barrie R. Nault

Research Collection School Of Computing and Information Systems

We model the diffusion of IT outsourcing using announcements about IT outsourcing deals. We estimate a lognormal diffusion curve to test whether IT outsourcing follows a pure diffusion process or there are contagion effects involved. The methodology permits us to study the consequences of outsourcing events, especially mega-deals with IT contract amounts that exceed US$1 billion. Mega-deals act, we theorize, as precipitating events that create a strong basis for contagion effects and are likely to affect decision-making by other firms in an industry. Then, we evaluate the role of different communication channels in the diffusion process of IT outsourcing by …


A Brain-Inspired Model Of Hierarchical Planner, Budhitama Subagdja, Ah-Hwee Tan Nov 2011

A Brain-Inspired Model Of Hierarchical Planner, Budhitama Subagdja, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Hierarchical planning is an approach of planning by composing and executing hierarchically arranged plans to solve some problems. Most symbolic-based hierarchical planners have been devised to allow the knowledge to be described expressively. However, a great challenge is to automatically seek and acquire new plans on the fly. This paper presents a novel neural-based model of hierarchical planning that can seek and acquired new plans on-line if the necessary knowledge are lacking. Inspired by findings in neuropsychology, plans can be inherently learnt, retrieved, and manipulated simultaneously rather than discretely processed like in most symbolic approaches. Using a multi-channel adaptive resonance …


Managing Successive Generation Product Diffusion In The Presence Of Strategic Consumers, Zhiling Guo Nov 2011

Managing Successive Generation Product Diffusion In The Presence Of Strategic Consumers, Zhiling Guo

Research Collection School Of Computing and Information Systems

Frequent new product release and technological uncertainty about the release time pose significant challenges for firms to manage successive generation of products. On the one hand, strategic consumers may delay their purchase decision and substitute the earlier generation with the newer generation product. On the other hand, the firm must fully anticipate consumer reactions and take into account the effect of their strategic behavior on product pricing and successive generation product diffusion. This paper proposes a prediction market to forecast new product release. We show that the market information aggregation mechanism can improve forecast accuracy of new product launch. Better …


Price Points And Price Rigidity, Daniel Levy, Dongwon Lee, Haipeng (Allen) Lee, Robert J. Kauffman, Mark Bergen Nov 2011

Price Points And Price Rigidity, Daniel Levy, Dongwon Lee, Haipeng (Allen) Lee, Robert J. Kauffman, Mark Bergen

Research Collection School Of Computing and Information Systems

We study the link between price points and price rigidity using two data sets: weekly scanner data and Internet data. We find that ‘‘9’’ is the most frequent ending for the penny, dime, dollar, and ten-dollar digits; the most common price changes are those that keep the price endings at ‘‘9’’; 9-ending prices are less likely to change than non-9-ending prices; and the average size of price change is larger for 9-ending than non-9- ending prices. We conclude that 9-ending contributes to price rigidity from penny to dollar digits and across a wide range of product categories, retail formats, and …


Unsupervised Multiple Kernel Learning, Jinfeng Zhuang, Jialei Wang, Steven C. H. Hoi, Xiangyang Lan Nov 2011

Unsupervised Multiple Kernel Learning, Jinfeng Zhuang, Jialei Wang, Steven C. H. Hoi, Xiangyang Lan

Research Collection School Of Computing and Information Systems

Traditional multiple kernel learning (MKL) algorithms are essentially supervised learning in the sense that the kernel learning task requires the class labels of training data. However, class labels may not always be available prior to the kernel learning task in some real world scenarios, e.g., an early preprocessing step of a classification task or an unsupervised learning task such as dimension reduction. In this paper, we investigate a problem of Unsupervised Multiple Kernel Learning (UMKL), which does not require class labels of training data as needed in a conventional multiple kernel learning task. Since a kernel essentially defines pairwise similarity …


Software Process Evaluation: A Machine Learning Approach, Ning Chen, Steven C. H. Hoi, Xiaokui Xiao Nov 2011

Software Process Evaluation: A Machine Learning Approach, Ning Chen, Steven C. H. Hoi, Xiaokui Xiao

Research Collection School Of Computing and Information Systems

Software process evaluation is essential to improve software development and the quality of software products in an organization. Conventional approaches based on manual qualitative evaluations (e.g., artifacts inspection) are deficient in the sense that (i) they are time-consuming, (ii) they suffer from the authority constraints, and (iii) they are often subjective. To overcome these limitations, this paper presents a novel semi-automated approach to software process evaluation using machine learning techniques. In particular, we formulate the problem as a sequence classification task, which is solved by applying machine learning algorithms. Based on the framework, we define a new quantitative indicator to …


Finding Relevant Answers In Software Forums, Swapna Gottopati, David Lo, Jing Jiang Nov 2011

Finding Relevant Answers In Software Forums, Swapna Gottopati, David Lo, Jing Jiang

Research Collection School Of Computing and Information Systems

Online software forums provide a huge amount of valuable content. Developers and users often ask questions and receive answers from such forums. The availability of a vast amount of thread discussions in forums provides ample opportunities for knowledge acquisition and summarization. For a given search query, current search engines use traditional information retrieval approach to extract webpages containing relevant keywords. However, in software forums, often there are many threads containing similar keywords where each thread could contain a lot of posts as many as 1,000 or more. Manually finding relevant answers from these long threads is a painstaking task to …


Consistent Community Identification In Complex Networks, Haewoon Kwak, Young-Ho Eom, Yoonchan Choi, Hawoong Jeong Nov 2011

Consistent Community Identification In Complex Networks, Haewoon Kwak, Young-Ho Eom, Yoonchan Choi, Hawoong Jeong

Research Collection School Of Computing and Information Systems

We have found that known community identification algorithms produce inconsistent communities when the node ordering changes at input. We use the pairwise membership probability and consistency to quantify the level of consistency across multiple runs of an algorithm. Based on these two metrics, we address the consistency problem without compromising the modularity. The key insight of the algorithm is to use pairwise membership probabilities as link weights. It offers a new tool in the study of community structures and their evolutions.


Pat 3: An Extensible Architecture For Building Multi-Domain Model Checkers, Yang Liu, Jun Sun, Jin Song Dong Nov 2011

Pat 3: An Extensible Architecture For Building Multi-Domain Model Checkers, Yang Liu, Jun Sun, Jin Song Dong

Research Collection School Of Computing and Information Systems

Model checking is emerging as an effective software verification method. Although it is desirable to have a dedicated model checker for each application domain, implementing one is rather challenging. In this work, we develop an extensible and integrated architecture in PAT3 (PAT version 3.*) to support the development of model checkers for wide range application domains. PAT3 adopts a layered design with an intermediate representation layer (IRL), which separates modeling languages from model checking algorithms so that the algorithms can be shared by different languages. IRL contains several common semantic models to support wide application domains, and builds both explicit …


Profit-Maximizing Firm Investments In Customer Information Security, Yong Yick Lee, Robert J. Kauffman, Ryan Sougstad Nov 2011

Profit-Maximizing Firm Investments In Customer Information Security, Yong Yick Lee, Robert J. Kauffman, Ryan Sougstad

Research Collection School Of Computing and Information Systems

When a customer interacts with a firm, extensive personal information often is gathered without the individual's knowledge. Significant risks are associated with handling this kind of information. Providing protection may reduce the risk of the loss and misuse of private information, but it imposes some costs on both the firm and its customers. Nevertheless, customer information security breaches still may occur. They have several distinguishing characteristics: (1) typically it is hard to quantify monetary damages related to them; (2) customer information security breaches may be caused by intentional attacks, as well as through unintentional organizational and customer behaviors; and (3) …


Towards Trajectory-Based Experience Sharing In A City, Byoungjip Kim, Youngki Lee, Sangjeong Lee, Yunseok Rhee, Junehwa Song Nov 2011

Towards Trajectory-Based Experience Sharing In A City, Byoungjip Kim, Youngki Lee, Sangjeong Lee, Yunseok Rhee, Junehwa Song

Research Collection School Of Computing and Information Systems

As location-aware mobile devices such as smartphones have now become prevalent, people are able to easily record their trajectories in daily lives. Such personal trajectories are a very promising means to share their daily life experiences, since important contextual information such as significant locations and activities can be extracted from the raw trajectories. In this paper, we propose MetroScope, a trajectory-based real-time and on-the-go experience sharing system in a metropolitan city. MetroScope allows people to share their daily life experiences through trajectories, and enables them to refer to other people's diverse and interesting experiences in a city. Eventually, MetroScope aims …


Beyond Search: Event-Driven Summarization For Web Videos, Richard Hong, Jinhui Tang, Hung-Khoon Tan, Chong-Wah Ngo, Shuicheng Yan, Tat-Seng Chua Nov 2011

Beyond Search: Event-Driven Summarization For Web Videos, Richard Hong, Jinhui Tang, Hung-Khoon Tan, Chong-Wah Ngo, Shuicheng Yan, Tat-Seng Chua

Research Collection School Of Computing and Information Systems

The explosive growth of Web videos brings out the challenge of how to efficiently browse hundreds or even thousands of videos at a glance. Given an event-driven query, social media Web sites usually return a large number of videos that are diverse and noisy in a ranking list. Exploring such results will be time-consuming and thus degrades user experience. This article presents a novel scheme that is able to summarize the content of video search results by mining and threading "key" shots, such that users can get an overview of main content of these videos at a glance. The proposed …


Learning Human Emotion Patterns For Modeling Virtual Humans, Shu Feng, Ah-Hwee Tan Nov 2011

Learning Human Emotion Patterns For Modeling Virtual Humans, Shu Feng, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

Emotion modeling is a crucial part in modeling virtual humans. Although various emotion models have been proposed, most of them focus on designing specific appraisal rules. As there is no unified framework for emotional appraisal, the appraisal variables have to be defined beforehand and evaluated in a subjective way. In this paper, we propose an emotion model based on machine learning methods by taking the following position: an emotion model should mirror actual human emotion in the real world and connect tightly with human inner states, such as drives, motivations and personalities. Specifically, a self-organizing neural model called Emotional Appraisal …


Applying Time-Bound Hierarchical Key Assignment In Wireless Sensor Networks, Wentao Zhu, Robert H. Deng, Jianying Zhou, Feng Bao Nov 2011

Applying Time-Bound Hierarchical Key Assignment In Wireless Sensor Networks, Wentao Zhu, Robert H. Deng, Jianying Zhou, Feng Bao

Research Collection School Of Computing and Information Systems

Access privileges in distributed systems can be effectively organized as a partial-order hierarchy that consists of distinct security classes, and are often designated with certain temporal restrictions. The time-bound hierarchical key assignment problem is to assign distinct cryptographic keys to distinct security classes according to their privileges so that users from a higher class can use their class key to derive the keys of lower classes, and these keys are time-variant with respect to sequentially allocated temporal units called time slots. In this paper, we explore applications of time-bound hierarchical key assignment in a wireless sensor network environment where there …