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2009

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Articles 241 - 270 of 1345

Full-Text Articles in Computer Sciences

Cs 466/666: Introduction To Formal Languages, Guozhu Dong Oct 2009

Cs 466/666: Introduction To Formal Languages, Guozhu Dong

Computer Science & Engineering Syllabi

CS 466/666 is an introduction to formal language and automata theory. In this course we will examine methods for defining syntax of languages and recognizing patterns: the syntax of languages can be defined using grammars and patterns accepted by finite state machines. Along with presenting the fundamentals of these two topics, the course will develop and investigate the relationships between language definition and pattern recognition. The text will be the third edition of Languages and Machines: An Introduction to the Theory of Computer Science, by Thomas Sudkamp.


Design And Implementation Of S-Marks: A Secure Middleware For Pervasive Computing Applications, Sheikh Iqbal Ahamed, Haifeng Li, Nilothpal Talukder, Mehrab Monjur, Chowdhury Sharif Hasan Oct 2009

Design And Implementation Of S-Marks: A Secure Middleware For Pervasive Computing Applications, Sheikh Iqbal Ahamed, Haifeng Li, Nilothpal Talukder, Mehrab Monjur, Chowdhury Sharif Hasan

Mathematics, Statistics and Computer Science Faculty Research and Publications

As portable devices have become a part of our everyday life, more people are unknowingly participating in a pervasive computing environment. People engage with not a single device for a specific purpose but many devices interacting with each other in the course of ordinary activity. With such prevalence of pervasive technology, the interaction between portable devices needs to be continuous and imperceptible to device users. Pervasive computing requires a small, scalable and robust network which relies heavily on the middleware to resolve communication and security issues. In this paper, we present the design and implementation of S-MARKS which incorporates device …


Analyzing The Video Popularity Characteristics Of Large-Scale User Generated Content Systems, Meeyoung Cha, Haewoon Kwak, Pablo Rodriguez, Yong-Yeol Ahn, Sue Moon Oct 2009

Analyzing The Video Popularity Characteristics Of Large-Scale User Generated Content Systems, Meeyoung Cha, Haewoon Kwak, Pablo Rodriguez, Yong-Yeol Ahn, Sue Moon

Research Collection School Of Computing and Information Systems

User generated content (UGC), now with millions of video producers and consumers, is re-shaping the way people watch video and TV. In particular, UGC sites are creating new viewing patterns and social interactions, empowering users to be more creative, and generating new business opportunities. Compared to traditional video-on-demand (VoD) systems, UGC services allow users to request videos from a potentially unlimited selection in an asynchronous fashion. To better understand the impact of UGC services, we have analyzed the world's largest UGC VoD system, YouTube, and a popular similar system in Korea, Daum Videos. In this paper, we first empirically show …


Image Registration Using Conformal Log Polar Mapping, Bala Krishna Vadapally Oct 2009

Image Registration Using Conformal Log Polar Mapping, Bala Krishna Vadapally

Electrical & Computer Engineering Theses & Dissertations

Image Registration is the process of aligning, or overlaying two images of the same scene that were taken at different times and/or from different viewing angles and/or by sensors with different modalities or resolutions. The variations in the imaging environment induce the difference between the images of the same scene. In our situation, we have two images of the same scene taken with two sensors, one in the visible and the other in the infrared (IR) domain. The cameras are placed adjacent to each other on a stable platform, and the images are captured almost simultaneously. This means that the …


Fault-Tolerance And Recovery In Wireless Sensor Networks, Kevin M. Somervill Oct 2009

Fault-Tolerance And Recovery In Wireless Sensor Networks, Kevin M. Somervill

Electrical & Computer Engineering Theses & Dissertations

The topic of Wireless Sensor Networks (WSNs) has gained considerable attention in the research community due to the variety of applications and interesting challenges in developing and deploying such networks. The typical WSN is significantly energy constrained and often deployed in harsh or even hostile environments, resulting in sensor nodes that are prone to failure. Failing nodes alter the topology of the network resulting in segmented routing paths and lost messages, ultimately reducing network efficiency. These issues spur the desire to develop energy-efficient, Fault-Tolerant (FT) algorithms that enable the network to persist in spite of the failed nodes. This work …


Unplanned Maintenance Scheduling A Lean Application Using Group Technology And Adaptive Conflict Resolution, Manish Shashibhushan Mittal Oct 2009

Unplanned Maintenance Scheduling A Lean Application Using Group Technology And Adaptive Conflict Resolution, Manish Shashibhushan Mittal

Mechanical & Aerospace Engineering Theses & Dissertations

Historically, production of ships is based on Group Technology (GT) with product oriented work breakdown structure. Recent GT applications have been effectively adapted to ship maintenance operations. In this thesis we have developed a GT based classification and coding system for the three basic requirements for maintenance operations: personnel, resources and space.

Traditionally unplanned maintenance activities are executed as and when the resources are available. This thesis presents a method for planning and scheduling these jobs with many of the traditional Lean manufacturing principles first adapted appropriately and then applied to Lean Maintenance. This method begins with identifying the priority …


Monte Carlo Model Of Light Propagation In Tissues And The Effects Of Phase Changes On The Light Intensity, Rakesh Choula Oct 2009

Monte Carlo Model Of Light Propagation In Tissues And The Effects Of Phase Changes On The Light Intensity, Rakesh Choula

Electrical & Computer Engineering Theses & Dissertations

Lasers, due to their unique properties, have a wide range of applications in the medical field. For accurate laser treatments that focus on bio-tissues, prior knowledge of the amount of laser power, spot size and its irradiation time are necessary. In order to predict the effects of lasers on tissues and their bio-effects, a first necessary step is the creation of a model that can predict the temperature distributions within the tissue following laser excitation. This involves modeling light propagation through the tissue with inclusion of internal scattering, and assessment of the energy deposited by the incoming photons. The next …


A Robust Method To Detect Concealed Weapons, Anand Gone Oct 2009

A Robust Method To Detect Concealed Weapons, Anand Gone

Electrical & Computer Engineering Theses & Dissertations

Concealed weapons detection is a large problem that is faced by the Police Department nowadays. There are many disasters caused by poor detection of the weapons. Since public safety is at risk there is a need to design an efficient detector that can detect the weapons hidden under the clothing. This thesis presents a novel method for detecting concealed weapons under clothing using image processing techniques. In this thesis IR imagery is used to capture an image which works on the principle of law of black body radiation. Image thresholding is performed on the captured data using Sauvola's adaptive thresholding …


Second Life Complements The Internet For Reference Librarians, Florence Tang Oct 2009

Second Life Complements The Internet For Reference Librarians, Florence Tang

Georgia Library Quarterly

The article describes the Second Life culture as an interactive virtual environment from the perspective of a reference librarian. The cited advantages of using Second Life are synchronous interaction with other people, clearer appearance of chat text messages, incorporation of social norms, and accessibility. Among the noted obstacles to using Second Life are its price, intentional distress of other avatars, empty virtual public places, less hierarchy among participants, chatting via rapid typing, and quick change of landscapes and avatars.


Unsupervised Face Alignment By Robust Nonrigid Mapping, Jianke Zhu, Luc Van Gool, Steven C. H. Hoi Oct 2009

Unsupervised Face Alignment By Robust Nonrigid Mapping, Jianke Zhu, Luc Van Gool, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

We propose a novel approach to unsupervised facial image alignment. Differently from previous approaches, that are confined to affine transformations on either the entire face or separate patches, we extract a nonrigid mapping between facial images. Based on a regularized face model, we frame unsupervised face alignment into the Lucas-Kanade image registration approach. We propose a robust optimization scheme to handle appearance variations. The method is fully automatic and can cope with pose variations and expressions, all in an unsupervised manner. Experiments on a large set of images showed that the approach is effective.


First Acm Sigmm International Workshop On Social Media (Wsm'09), Suzanne Boll, Steven C. H. Hoi, Jiebo Luo, Rong Jin, Dong Xu, Irwin King Oct 2009

First Acm Sigmm International Workshop On Social Media (Wsm'09), Suzanne Boll, Steven C. H. Hoi, Jiebo Luo, Rong Jin, Dong Xu, Irwin King

Research Collection School Of Computing and Information Systems

No abstract provided.


Semantics-Preserving Bag-Of-Words Models For Efficient Image Annotation, Lei Wu, Steven C. H. Hoi, Nenghai Yu Oct 2009

Semantics-Preserving Bag-Of-Words Models For Efficient Image Annotation, Lei Wu, Steven C. H. Hoi, Nenghai Yu

Research Collection School Of Computing and Information Systems

The Bag-of-Words (BoW) model is a promising image representation for annotation. One critical limitation of existing BoW models is the semantic loss during the codebook generation process, in which BoW simply clusters visual words in Euclidian space. However, distance between two visual words in Euclidean space does not necessarily reflect the semantic distance between the two concepts, due to the semantic gap between low-level features and high-level semantics. In this paper, we propose a novel scheme for learning a codebook such that semantically related features will be mapped to the same visual word. In particular, we consider the distance between …


First Acm Sigmm International Workshop On Social Media (Wsm'09), Suzanne Boll, Steven C. H. Hoi, Jiebo Luo, Rong Jin, Dong Xu, Irwin King Oct 2009

First Acm Sigmm International Workshop On Social Media (Wsm'09), Suzanne Boll, Steven C. H. Hoi, Jiebo Luo, Rong Jin, Dong Xu, Irwin King

Research Collection School Of Computing and Information Systems

The ACM SIGMM International Workshop on Social Media(WSM’09) is the first workshop held in conjunction withthe ACM International Multimedia Conference (MM’09) atBejing, P.R. China, 2009. This workshop provides a forumfor researchers and practitioners from all over the world toshare information on their latest investigations on social mediaanalysis, exploration, search, mining, and emerging newsocial media applications.


A Service Choice Model For Optimizing Taxi Service Delivery, Shih-Fen Cheng, Xin Qu Oct 2009

A Service Choice Model For Optimizing Taxi Service Delivery, Shih-Fen Cheng, Xin Qu

Research Collection School Of Computing and Information Systems

Taxi service has undergone radical revamp in recent years. In particular, significant investments in communication system and GPS devices have improved quality of taxi services through better dispatches. In this paper, we propose to leverage on such infrastructure and build a service choice model that helps individual drivers in deciding whether to serve a specific taxi stand or not. We demonstrate the value of our model by applying it to a real-world scenario. We also highlight interesting new potential approaches that could significantly improve the quality of taxi services.


Digital Logic Based Encoding Strategies For Steganography On Voice-Over-Ip, Hui Tian, Ke Zhou, Hong Jiang, Dan Feng Oct 2009

Digital Logic Based Encoding Strategies For Steganography On Voice-Over-Ip, Hui Tian, Ke Zhou, Hong Jiang, Dan Feng

School of Computing: Conference and Workshop Papers

This paper presents three encoding strategies based on digital logic for steganography on Voice over IP (VoIP), which aim to enhance the embedding transparency. Differing from previous approaches, our strategies reduce the embedding distortion by improving the similarity between the cover and the covert message using digital logical transformations, instead of reducing the amount of the substitution bits. Therefore, by contrast, our strategies will improve the embedding transparency without sacrificing the embedding capacity. Of these three strategies, the first one adopts logical operations, the second one employs circular shifting operations, and the third one combines the operations of the first …


Mining Quantified Temporal Rules: Formalism, Algorithms, And Evaluation, David Lo, Ganesan Ramalingam, Venkatesh-Prasad Ranganath, Kapil Vaswani Oct 2009

Mining Quantified Temporal Rules: Formalism, Algorithms, And Evaluation, David Lo, Ganesan Ramalingam, Venkatesh-Prasad Ranganath, Kapil Vaswani

Research Collection School Of Computing and Information Systems

Libraries usually impose constraints on how clients should use them. Often these constraints are not well-documented. In this paper, we address the problem of recovering such constraints automatically, a problem referred to as specification mining. Given some client programs that use a given library, we identify constraints on the library usage that are (almost) satisfied by the given set of clients.The class of rules we target for mining combines simple binary temporal operators with state predicates (involving equality constraints) and quantification. This is a simple yet expressive subclass of temporal properties that allows us to capture many common API usage …


Contributing Factors To Pointcut Fragility, Phil Greenwood, Awais Rashid, Raffi Khatchadourian Oct 2009

Contributing Factors To Pointcut Fragility, Phil Greenwood, Awais Rashid, Raffi Khatchadourian

Publications and Research

Pointcut fragility is a well-documented problem of Aspect-Oriented Programming with changes to the base-code causing join points to incorrectly fall in or out of scope. In order to combat this problem a tool was developed that provides mechanical assistance to pointcut maintenance. This tool relied on the deep structural commonalities between program elements to detect when pointcut fragility occurs. During the assessment of this tool a number of common practices were uncovered that were employed both in the aspect and base-code that contributed to or prevented pointcut fragility. This paper documents the practices uncovered and describes how they can affect …


Compromising Anonymous Communication Systems Using Blind Source Separation, Ye Zhu, Riccardo Bettati Oct 2009

Compromising Anonymous Communication Systems Using Blind Source Separation, Ye Zhu, Riccardo Bettati

Electrical and Computer Engineering Faculty Publications

We propose a class of anonymity attacks to both wired and wireless anonymity networks. These attacks are based on the blind source separation algorithms widely used to recover individual signals from mixtures of signals in statistical signal processing. Since the philosophy behind the design of current anonymity networks is to mix traffic or to hide in crowds, the proposed anonymity attacks are very effective. The flow separation attack proposed for wired anonymity networks can separate the traffic in a mix network. Our experiments show that this attack is effective and scalable. By combining the flow separation method with frequency spectrum …


Scalable Detection Of Partial Near-Duplicate Videos By Visual-Temporal Consistency, Hung-Khoon Tan, Chong-Wah Ngo, Richang Hong, Tat-Seng Chua Oct 2009

Scalable Detection Of Partial Near-Duplicate Videos By Visual-Temporal Consistency, Hung-Khoon Tan, Chong-Wah Ngo, Richang Hong, Tat-Seng Chua

Research Collection School Of Computing and Information Systems

Following the exponential growth of social media, there now exist huge repositories of videos online. Among the huge volumes of videos, there exist large numbers of near-duplicate videos. Most existing techniques either focus on the fast retrieval of full copies or near-duplicates, or consider localization in a heuristic manner. This paper considers the scalable detection and localization of partial near-duplicate videos by jointly considering visual similarity and temporal consistency. Temporal constraints are embedded into a network structure as directed edges. Through the structure, partial alignment is novelly converted into a network flow problem where highly efficient solutions exist. To precisely …


Desktop Virtualisation Scaling Experiments With Virtualbox, John Griffin, Paul Doyle Oct 2009

Desktop Virtualisation Scaling Experiments With Virtualbox, John Griffin, Paul Doyle

9th. IT & T Conference

With recent advances in virtualization and a growing concern regarding the administration and cooling costs associated with managing legacy servers, organisations are moving towards server and desktop virtualisation. Virtualisation provides the ability to provision a servers resources efficiently thus increasing hardware utilisation and reducing costs. While server virtualization provides clear advantages with regard to system management, higher system availability and lower recovery times, desktop virtualization is often complicated by the issue of determining the number of concurrent virtual desktops capable of running on a single server while providing acceptable performance to each desktop user. Determining the number of virtualised desktops …


Power Save-Based Adaptive Multimedia Delivery Mechanism, David Mcmullin, Ramona Trestian, Gabriel-Miro Muntean Oct 2009

Power Save-Based Adaptive Multimedia Delivery Mechanism, David Mcmullin, Ramona Trestian, Gabriel-Miro Muntean

9th. IT & T Conference

The use of mobile computing devices has become more and more common as such devices have become more and more affordable and powerful. With increases in throughput speed and decreases in device size, wireless multimedia streaming to battery powered mobile devices has become widespread. However, the battery power has not kept up with the advances in technology and has not increased so rapidly. This deficiency in battery power provides motivation for development of more energy efficient multimedia streaming methods and procedures. As such, an adaptive delivery mechanism is proposed to take into account the various drains on battery life and …


A Study Of Mobile Internet Capability Trends To Assess The Effectiveness Of The W3c Default Delivery Context (Ddc), Ivan Dunn, Gary Clynch Oct 2009

A Study Of Mobile Internet Capability Trends To Assess The Effectiveness Of The W3c Default Delivery Context (Ddc), Ivan Dunn, Gary Clynch

9th. IT & T Conference

The mobile Internet is becoming increasingly popular, but the usability of many Web applications provides a negative mobile Internet experience. This paper researched the Internet capabilities of Web-enabled mobile phones through statistics generated using the R programming environment with data sourced from MobileAware’s Device Description Repository (DDR). Time series analysis and measures of location were applied to the data set. Hands-on testing using selected mobile browsers were carried out to backup and prove findings. The data set contained 1384 device descriptions from LG, Nokia, Motorola, Samsung and Sony Ericsson mobile phones that have a browser capable rendering XHTML Basic 1.0 …


Sensing Learner Interest Through Eye Tracking, Haolin Wei, Arthir-Nicolae Moldovan, Cristina Muntean Oct 2009

Sensing Learner Interest Through Eye Tracking, Haolin Wei, Arthir-Nicolae Moldovan, Cristina Muntean

9th. IT & T Conference

Due to the rapidly growing of the amount of information, a stronger need emerges for efficient and flexible strategies for personalisation of the educational content. E-learning systems are very helpful for learners, however, people differ in knowledge level, learning styles and may seek for different information when they access web based e-learning systems. Therefore, content adapted to the user’s needs should be supported by the e-learning systems. In this paper we introduce a new e-learning environment that makes use of eye tracking mechanism to follow learner interest in certain topics and to perform content personalisation. The framework of the e-learning …


Universal Design, Education And Technology, Ciaran O'Leary, Damian Gordon Oct 2009

Universal Design, Education And Technology, Ciaran O'Leary, Damian Gordon

9th. IT & T Conference

Universal Design is an approach to design which insists upon the consideration of users with diverse levels of ability. Rather than representing a specialist approach to design, it is recognised that Universal Design results in a better design for all. Furthermore, by isolating design for disability as an independent topic in education, or ignoring it altogether, educators create an exclusionist perception of the role and place of individuals with disability in modern society. Modern education programmes which teach design skills are enhanced in quality by mainstreaming Universal Design as a core topic, permeating all that surrounds it. This paper describes …


Comparison Of Feature Classification Algorithm For Activity Recognition Based On Accelerometer And Heart Rate Data, Dominic Maguire, Richard Frisby Oct 2009

Comparison Of Feature Classification Algorithm For Activity Recognition Based On Accelerometer And Heart Rate Data, Dominic Maguire, Richard Frisby

9th. IT & T Conference

This paper describes a project to compare two feature classification algorithms used in activity recognition in relation to accelerometer and heart rate data. Data was collected from six male and female subjects using a single tri-axial accelerometer and heart monitor attached to each subject’s dominant thigh. Subjects carried out eight activities and the data was labelled semi-automatically. Features (mean, standard deviation, energy, correlation and mean heart rate) were extracted from the data using a window of 256 (3.4 seconds) and an overlap of 50%. Two classifers, k-NN and J48, were evaluated for activity recognition with 10-fold validation with k-NN (k …


Development Of A Moodle Course Content Filter Using Meta Data, Kyle Goslin, Markus Hoffmann Oct 2009

Development Of A Moodle Course Content Filter Using Meta Data, Kyle Goslin, Markus Hoffmann

9th. IT & T Conference

Moodle is an E-Learning platform that is in use by many educational institutions across the world. This paper outlines the development of a Course page Content Filter created in PHP which can be applied to a Moodle course page to filter the course’s learning objects, displaying only those documents matching the filter selections. The Course Content Filter has been developed as a code patch to be installed to the Moodle installation and activated by the Moodle administrator. It comprises of additional settings to both the Moodle course page and the learning object upload pages. Filter controls appear at the top …


An Improved Camshift Algorithm For Target Tracking In Video Surveillance, Chunrong Zhang, Yuansong Qiao, Enda Fallon, Chiangqiao Xu Oct 2009

An Improved Camshift Algorithm For Target Tracking In Video Surveillance, Chunrong Zhang, Yuansong Qiao, Enda Fallon, Chiangqiao Xu

9th. IT & T Conference

Target tracking in a cluttered environment remains a challenging research topic. The task of target tracking is a key component of video surveillance and monitoring systems. In this paper, we present an improved CamShift algorithm for tracking a target in video sequences in real time. Firstly, a background-weighted histogram which helps to distinguish the target from the background and other targets is introduced. Secondly, the window size is calculated to track the target as its shape and orientation change. Finally, we use a Kalman Filter to avoid being trapped by a local maximum. The introduction of the Kalman Filter also …


Efficient Uwb Indoor Localisation Using A Ray-Tracing Propagation Tool, Tam Huynh, Conor Brennan Oct 2009

Efficient Uwb Indoor Localisation Using A Ray-Tracing Propagation Tool, Tam Huynh, Conor Brennan

9th. IT & T Conference

A novel method of applying Ray Tracing to the problem of Ultra-wide Band (UWB) indoor userlocalization is presented. This novel method for UWB localization is based on correlation between the received signal and a database of pre-computed ray-traced signals computed on a search curve. In the absence of real data the technique is validated by generating synthetic received signals using ray tracing plus Rayleigh distributed random multipath clusters as well as random amplitude and delay factors which account for database uncertainty. Results are presented that indicate that acceptable location and tracking performance can be achieved with a single sensor.


Qos-Aware Iptv Routing Algorithms, Patrick Mcdonagh, Philip Perry, Liam Murphy Oct 2009

Qos-Aware Iptv Routing Algorithms, Patrick Mcdonagh, Philip Perry, Liam Murphy

9th. IT & T Conference

The aim of this paper is to describe how QoS (Quality of Service) metrics such as packet delay can be used to optimise the routing algorithms used in a network where IP Television (IPTV) content is being distributed. We outline the usage of metric instrumentation in a network to gauge the bandwidth limits of the network and how to use this information to generate a model of network link utilisation. Furthermore, we show that as the link utilisation rates change in our network model, we can modify the network routing algorithms to optimise the distribution of IPTV content to end-users.


Parallelised Em Wave Progagation Modelling For Accurate Network Simulation, Catalin David, Conor Brennan, Olga Ormond, Marie Mullen Oct 2009

Parallelised Em Wave Progagation Modelling For Accurate Network Simulation, Catalin David, Conor Brennan, Olga Ormond, Marie Mullen

9th. IT & T Conference

A description of ongoing work which aims to provide better quality propagation models for use in network simulators is provided in this paper. A 3D ray-tracing model is described which allows for accurate specification of a variety of wave scattering phenomena. Details of its parallelisation are given as well as a discussion of future work including the incorporation of a visibility algorithm. Results illustrate the increased realism obtained by using site-specific propagation models.