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2012

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Articles 1711 - 1740 of 1947

Full-Text Articles in Computer Sciences

Enhancing Description Logics For Rules Coverage, David Carral Martinez Jan 2012

Enhancing Description Logics For Rules Coverage, David Carral Martinez

Browse all Theses and Dissertations

This thesis is a formal study on how to extend the set of logic constructors of description logics languages, used for knowledge representation in the Semantic Web field to capture some of the previously exclusive rules expressivity. Description Logics, the logics underpinning the Web Ontology Language OWL, and rules are currently the most prominent paradigms used for modeling knowledge for the Semantic Web. While both of these approaches are based on classical logic, the paradigms also differ significantly, so that naive combinations result in undesirable properties such as undecidability. Recent work has shown that many rules can in fact be …


A Hardware Compact Genetic Algorithm For Hover Improvement In An Insect-Scale Flapping-Wing Micro Air Vehicle, Kathleen M. Timmerman Jan 2012

A Hardware Compact Genetic Algorithm For Hover Improvement In An Insect-Scale Flapping-Wing Micro Air Vehicle, Kathleen M. Timmerman

Browse all Theses and Dissertations

Wing and airframe damage to insect scale micro air vehicles potentially cause significant losses in pose and position control precision. Although one can imagine many possible means of adapting the flight controllers to restore precise pose and position control, severe limits on computational resources available on-board an insect sized vehicle render many of them impractical. Additionally, limits on sensory capability degrade any such vehicle's ability to critique its own performance. Any adaptive solutions one would propose to recover flight trajectory precision, therefore, would require a resource light implementation, preferably without need for relatively expensive floating-point operations, along with the capability …


Knowledge Acquisition In A System, Christopher J. Thomas Jan 2012

Knowledge Acquisition In A System, Christopher J. Thomas

Browse all Theses and Dissertations

I present a method for growing the amount of knowledge available on the Web using a hermeneutic method that involves background knowledge, Information Extraction techniques and validation through discourse and use of the extracted information.

I present the metaphor of the "Circle of Knowledge on the Web". In this context, knowledge acquisition on the web is seen as analogous to the way scientific disciplines gradually increase the knowledge available in their field.

Here, formal models of interest domains are created automatically or manually and then validated by implicit and explicit validation methods before the statements in the created models can …


Abstraction Driven Application And Data Portability In Cloud Computing, Ajith Harshana Ranabahu Jan 2012

Abstraction Driven Application And Data Portability In Cloud Computing, Ajith Harshana Ranabahu

Browse all Theses and Dissertations

Cloud computing has changed the way organizations create, manage, and evolve their applications. While many organizations are eager to use the cloud, tempted by substantial cost savings and convenience, the implications of using clouds are still not well understood. One of the major concerns in cloud adoption is the vendor lock-in of applications, caused by the heterogeneity of the numerous cloud service offerings. Vendor locked applications are difficult, if not impossible to port from one cloud system to another, forcing cloud service consumers to use undesired or suboptimal solutions. This dissertation investigates a complete and comprehensive solution to address the …


Winding Resistance And Winding Power Loss Of High-Frequency Power Inductors, Rafal P. Wojda Jan 2012

Winding Resistance And Winding Power Loss Of High-Frequency Power Inductors, Rafal P. Wojda

Browse all Theses and Dissertations

The scope of this research is concentrated on analytical winding size optimization (thickness or diameter) of high-frequency power inductors wound with foil, solid-round wire, multi-strand wire, and litz-wire conductors.

The first part of this research concerns analytical optimization of the winding size (thickness or diameter) for the inductors conducting a sinusoidal current. Estimation of winding resistance in individual inductor layers made of foil, taking into account the skin and proximity effects is performed. Approximated equations for the winding power loss in each layer are given and the optimal values of foil thickness for each layer are derived.

A low- and …


Optimization Of Spectrum Allocation In Cognitive Radio And Dynamic Spectrum Access Networks, Tao Zhang Jan 2012

Optimization Of Spectrum Allocation In Cognitive Radio And Dynamic Spectrum Access Networks, Tao Zhang

Browse all Theses and Dissertations

Spectrum has become a treasured commodity. However, many licensed frequency bands exclusively assigned to the primary license holders (also called primary users) remain relatively unused or under-utilized for most of the time. Allowing other users (also called secondary users) without a license to operate in these bands with no interference becomes a promising way to satisfy the fast growing needs for frequency spectrum resources. A cognitive radio adapts to the environment it operates in by sensing the spectrum and quickly decides on appropriate frequency bands and transmission parameters to use in order to achieve certain performance goals. One of the …


Geometric Graph Theory And Wireless Sensor Networks, Deniz Sarioz Jan 2012

Geometric Graph Theory And Wireless Sensor Networks, Deniz Sarioz

Dissertations, Theses, and Capstone Projects

In this work, we apply geometric and combinatorial methods to explore a variety of problems motivated by wireless sensor networks. Imagine sensors capable of communicating along straight lines except through obstacles like buildings or barriers, such that the communication network topology of the sensors is their visibility graph. Using a standard distributed algorithm, the sensors can build common knowledge of their network topology.

We first study the following inverse visibility problem: What positions of sensors and obstacles define the computed visibility graph, with fewest obstacles? This is the problem of finding a minimum obstacle representation of a graph. This minimum …


Systems And Methods For Transaction Account Offerings, Clinton Allen, Michael Digregorio, Glade Erikson, Deepinder Gulati, Jacob Plammoottil Jacob, Sanjiv Khosla, Seema Chokshi Jan 2012

Systems And Methods For Transaction Account Offerings, Clinton Allen, Michael Digregorio, Glade Erikson, Deepinder Gulati, Jacob Plammoottil Jacob, Sanjiv Khosla, Seema Chokshi

Research Collection School Of Computing and Information Systems

A method for receiving a user input for providing offerings is disclosed. Fields may be populated for creating a database query for matching a selection of offerings to a population of customers. Data may be received from the database, in response to interactively building the query and/or executing the query. Multiple rank ordered results may be produced for comparison, wherein the producing uses preprogrammed analytics, data from the database and user input, and wherein the results include customer lists linked to a distinct offering and a preferred delivery channel of the offering to a customer. A transaction account may be …


Hypotheses Generation As Supervised Link Discovery With Automated Class Labeling On Large-Scale Biomedical Concept Networks, Jayasimha R. Katukuri, Ying Xie, Vijay Raghavan, Ashish Gupta Jan 2012

Hypotheses Generation As Supervised Link Discovery With Automated Class Labeling On Large-Scale Biomedical Concept Networks, Jayasimha R. Katukuri, Ying Xie, Vijay Raghavan, Ashish Gupta

Faculty Articles

Computational approaches to generate hypotheses from biomedical literature have been studied intensively in recent years. Nevertheless, it still remains a challenge to automatically discover novel, cross-silo biomedical hypotheses from large-scale literature repositories. In order to address this challenge, we first model a biomedical literature repository as a comprehensive network of biomedical concepts and formulate hypotheses generation as a process of link discovery on the concept network. We extract the relevant information from the biomedical literature corpus and generate a concept network and concept-author map on a cluster using Map-Reduce framework. We extract a set of heterogeneous features such as random …


Redistricting Using Constrained Polygonal Clustering, Deepti Joshi, Leen-Kiat Soh, Ashok Samal Jan 2012

Redistricting Using Constrained Polygonal Clustering, Deepti Joshi, Leen-Kiat Soh, Ashok Samal

School of Computing: Faculty Publications

Redistricting is the process of dividing a geographic area consisting of spatial units—often represented as spatial polygons—into smaller districts that satisfy some properties. It can therefore be formulated as a set partitioning problem where the objective is to cluster the set of spatial polygons into groups such that a value function is maximized [1]. Widely used algorithms developed for point-based data sets are not readily applicable because polygons introduce the concepts of spatial contiguity and other topological properties that cannot be captured by representing polygons as points. Furthermore, when clustering polygons, constraints such as spatial contiguity and unit distributedness should …


An Efficient Water-Filling Algorithm For Power Allocation In Ofdm-Based Cognitive Radio Systems, Qilin Qi, Yaoqing Lamar Yang Jan 2012

An Efficient Water-Filling Algorithm For Power Allocation In Ofdm-Based Cognitive Radio Systems, Qilin Qi, Yaoqing Lamar Yang

School of Computing: Conference and Workshop Papers

In this paper, we present a new water-filling algorithm for power allocation in Orthogonal Frequency Division Multiplexing (OFDM) – based cognitive radio systems. The conventional water-filling algorithm cannot be directly employed for power allocation in a cognitive radio system, because there are more power constraints in the cognitive radio power allocation problem than in the classic OFDM system. In this paper, a novel algorithm based on iterative water-filling is presented to overcome such limitations. However, the computational complexity in iterative water-filling is very high. Thus, we explore features of the water-filling algorithm and propose a low-complexity algorithm using power-increment or …


Adaptive Energy-Efficient Task Partitioning For Heterogeneous Multi-Core Multiprocessor Real-Time Systems, Shivashis Saha, Jitender S. Deogun, Ying Lu Jan 2012

Adaptive Energy-Efficient Task Partitioning For Heterogeneous Multi-Core Multiprocessor Real-Time Systems, Shivashis Saha, Jitender S. Deogun, Ying Lu

School of Computing: Conference and Workshop Papers

The designs of heterogeneous multi-core multiprocessor real-time systems are evolving for higher energy efficiency at the cost of increased heat density. This adversely effects the reliability and performance of the real-time systems. Moreover, the partitioning of periodic real-time tasks based on their worst case execution time can lead to significant energy wastage.

In this paper, we investigate adaptive energy-efficient task partitioning for heterogeneous multi-core multiprocessor realtime systems. We use a power model which incorporates the impact of temperature and voltage of a processor on its static power consumption. Two different thermal models are used to estimate the peak temperature of …


Hyscaleii: A High Performance Hybrid Optical Network Architecture For Data Centers, Shivashis Saha, Jitender S. Deogun, Lisong Xu Jan 2012

Hyscaleii: A High Performance Hybrid Optical Network Architecture For Data Centers, Shivashis Saha, Jitender S. Deogun, Lisong Xu

School of Computing: Conference and Workshop Papers

Tremendous growth in data-intensive cloud applications have resulted in an increased demand for highly scalable data center network (DCN) architectures with high throughput and low network complexity. In this paper, we propose HyScaleII to improve the performance of HyScale [17]. HyScaleII is a switchcentric high performance hybrid optical network based DCN architecture that has most of the desirable properties of a data center, e.g. high scalability, low diameter, high bisection width, fault-tolerance, and low network complexity. We also present an efficient and simple routing scheme called HySII routing, which exploits the structural properties of HyScaleII. In our experiments, HyScaleII …


Finding Suitable Programs: Semantic Search With Incomplete And Lightweight Specifications, Kathryn T. Stolee Jan 2012

Finding Suitable Programs: Semantic Search With Incomplete And Lightweight Specifications, Kathryn T. Stolee

School of Computing: Conference and Workshop Papers

Finding suitable code for reuse is a common task for programmers. Two general approaches dominate the code search literature: syntactic and semantic. While queries for syntactic search are easy to compose, the results are often vague or irrelevant. On the other hand, a semantic search may return relevant results, but current techniques require developers to write specifications by hand, are costly as potentially matching code need to be executed to verify congruence with the specifications, or only return exact matches. In this work, we propose an approach for semantic search in which programmers specify lightweight, incomplete specifications and an SMT …


Space-Efficient Algorithms For Reachability In Surface-Embedded Graphs, Derrick Stolee, N. V. Vinodchandran Jan 2012

Space-Efficient Algorithms For Reachability In Surface-Embedded Graphs, Derrick Stolee, N. V. Vinodchandran

School of Computing: Conference and Workshop Papers

This work presents a log-space reduction which compresses an n-vertex directed acyclic graph with m(n) sources embedded on a surface of genus g(n), to a graph with O(m(n) + g(n)) vertices while preserving reachability between a given pair of vertices. Applying existing algorithms to this reduced graph yields new deterministic algorithms with improved space bounds as well as improved simultaneous time space bounds for the reachability problem over a large class of directed acyclic graphs. Specifically, it significantly extends the class of surface-embedded graphs with log-space reachability algorithms: from planar graphs with O(log n) sources, to graphs with …


Mobile Data Harvesting In Wireless Underground Sensor Networks, John Tooker, Mehmet C. Vuran Jan 2012

Mobile Data Harvesting In Wireless Underground Sensor Networks, John Tooker, Mehmet C. Vuran

School of Computing: Conference and Workshop Papers

Wireless Underground Sensor Networks (WUSNs) allow for continuous field monitoring without interfering with aboveground activities, such as plowing or football games. Due to the increased path loss in soil, it is challenging to ensure that a large-scale underground network is connected while still being cost effective in terms of deployment and maintenance.

In this paper, a practical WUSN architecture is developed, consisting of mobile nodes that harvest data from stationary underground nodes. To this end, the impacts of packet size and error control schemes on network performance are investigated through field experiments. By developing a better understanding of the wireless …


Amplifying Tests To Validate Exception Handling Code, Pingyu Zhang, Sebastian Elbaum Jan 2012

Amplifying Tests To Validate Exception Handling Code, Pingyu Zhang, Sebastian Elbaum

School of Computing: Conference and Workshop Papers

Validating code handling exceptional behavior is difficult, particularly when dealing with external resources that may be noisy and unreliable, as it requires: 1) the systematic exploration of the space of exceptions that may be thrown by the external resources, and 2) the setup of the context to trigger specific patterns of exceptions. In this work we present an approach that addresses those difficulties by performing an exhaustive amplification of the space of exceptional behavior associated with an external resource that is exercised by a test suite. Each amplification attempts to expose a program exception handling construct to new behavior by …


Sensing Through The Continent: Towards Monitoring Migratory Birds Using Cellular Sensor Networks, David Anthony, William P. Bennett, Mehmet C. Vuran, Matthew B. Dwyer, Sebastian Elbaum, Anne Lacy, Mike Engels, Walter Wehtje Jan 2012

Sensing Through The Continent: Towards Monitoring Migratory Birds Using Cellular Sensor Networks, David Anthony, William P. Bennett, Mehmet C. Vuran, Matthew B. Dwyer, Sebastian Elbaum, Anne Lacy, Mike Engels, Walter Wehtje

School of Computing: Conference and Workshop Papers

This paper presents CraneTracker, a novel sensor platform for monitoring migratory birds. The platform is designed to monitor Whooping Cranes, an endangered species that conducts an annual migration of 4, 000 km between southern Texas and north-central Canada. CraneTracker includes a rich set of sensors, a multi-modal radio, and power control circuitry for sustainable, continental-scale information delivery during migration. The need for large-scale connectivity motivates the use of cellular technology in low-cost sensor platforms augmented by a low-power transceiver for ad-hoc connectivity. This platform leads to a new class of cellular sensor networks (CSNs) for time-critical and mobile sensing applications. …


Self‐Regulating Action Exploration In Reinforcement Learning, Teck-Hou Teng, Ah-Hwee Tan, Yuan-Sin Tan Jan 2012

Self‐Regulating Action Exploration In Reinforcement Learning, Teck-Hou Teng, Ah-Hwee Tan, Yuan-Sin Tan

Research Collection School Of Computing and Information Systems

The basic tenet of a learning process is for an agent to learn for only as much and as long as it is necessary. With reinforcement learning, the learning process is divided between exploration and exploitation. Given the complexity of the problem domain and the randomness of the learning process, the exact duration of the reinforcement learning process can never be known with certainty. Using an inaccurate number of training iterations leads either to the non-convergence or the over-training of the learning agent. This work addresses such issues by proposing a technique to self-regulate the exploration rate and training duration …


Consumer-Driven Innovation Management, Arcot Desai Narasimhalu, Shekhar Mitra Jan 2012

Consumer-Driven Innovation Management, Arcot Desai Narasimhalu, Shekhar Mitra

Research Collection School Of Computing and Information Systems

The evolution of human society leads to increased affluence and prosperity of certain populations, sometimes at the expense of well-established markets. Market leaders in products and services tend to be so focused on their current customer base that they are caught off guard with the changes in markets created by the evolution. These changes often go unnoticed until it is too late. The change in customer base often requires the repositioning of products and services through innovations, which address new and emerging markets. Some of these changes could potentially result in tectonic market shifts that force innovation managers to involve …


Predictive Modeling For Navigating Social Media, Meiqun Hu Jan 2012

Predictive Modeling For Navigating Social Media, Meiqun Hu

Dissertations and Theses Collection (Open Access)

Social media changes the way people use the Web. It has transformed ordinary Web users from information consumers to content contributors. One popular form of content contribution is social tagging, in which users assign tags to Web resources. By the collective efforts of the social tagging community, a new information space has been created for information navigation. Navigation allows serendipitous discovery of information by examining the information objects linked to one another in the social tagging space. In this dissertation, we study prediction tasks that facilitate navigation in social tagging systems. For social tagging systems to meet complex navigation needs …


Robust Execution Strategy For Scheduling Under Uncertainity, Na Fu Jan 2012

Robust Execution Strategy For Scheduling Under Uncertainity, Na Fu

Dissertations and Theses Collection (Open Access)

Resource Constrained Project Scheduling Problems with minimum and maximum time lags (RCPSP/max) provides a general model for resource scheduling in many real-world problems (such as manufacturing and construction engineering). Due to its practical importance and generality, providing effective algorithms and scalable solutions for RCPSP/max is a topic of growing research. Traditional methods have addressed deterministic models with all parameters known with certainty. In this thesis, we are concerned with RCPSP/max problems in an uncertain environment where durations of activities are stochastic and resource availabilities are subject to unforeseen breakdowns. We propose methods for generating robust execution strategy to protect against …


Go Niche Or Go Home: Influence Maximization In The Presence Of Strong Opponent, Long Foong Liow Jan 2012

Go Niche Or Go Home: Influence Maximization In The Presence Of Strong Opponent, Long Foong Liow

Dissertations and Theses Collection (Open Access)

In hotly contested product categories dominated by a few powerful firms, it is quite common for weaker or late entrants to focus only on particular segments of the whole market. The rationale for such strategy is intuitive: to avoid direct confrontation with heavy-weight firms, and to concentrate in segments where these weaker firms have comparative advantages. In marketing, this is what people called “go niche or go home”. The niche-building strategy may rely on “homophily”, which implies that consumers in a particular market segment might possess certain set of attributes that cause them to appreciate certain products better (in other …


A Survey Of Computer And Network Security Support From Computer Retailers To Consumers In Australia, Patryk Szewczyk Jan 2012

A Survey Of Computer And Network Security Support From Computer Retailers To Consumers In Australia, Patryk Szewczyk

Australian Information Security Management Conference

Previously undertaken research suggests that novice end-users rely on computer retailers for security advice and support during and after a sale has occurred. This paper documents the survey results of computer and network security support provided to consumers by retailers in Perth, Western Australia between 2011 and 2012. The conducted survey shows that in the majority of cases, computers retailers were favourable in providing support and recommendations. However, these views were found to be flawed, confusing and do little to ensure that end-users are not victimized by cyber crime.


Perpetual Requirements Engineering, Manuel Alfonso Peralta Jan 2012

Perpetual Requirements Engineering, Manuel Alfonso Peralta

LSU Doctoral Dissertations

This dissertation attempts to make a contribution within the fields of distributed systems, security, and formal verification. We provide a way to formally assess the impact of a given change in three different contexts. We have developed a logic based on Lewis’s Counterfactual Logic. First we show how our approach is applied to a standard sequential programming setting. Then, we show how a modified version of the logic can be used in the context of reactive systems and sensor networks. Last but not least we show how this logic can be used in the context of security systems. Traditionally, change …


A New Model For Coalition Formation Games, Alfred Samman Jan 2012

A New Model For Coalition Formation Games, Alfred Samman

LSU Doctoral Dissertations

We present two broad categories of games, namely, group matching games and bottleneck routing games on grids. Borrowing ideas from coalition formation games, we introduce a new category of games which we call group matching games. We investigate how these games perform when agents are allowed to make selfish decisions that increase their individual payoffs versus when agents act towards the social benefit of the game as a whole. The Price of Anarchy (PoA) and Price of Stability (PoS) metrics are used to quantify these comparisons. We show that the PoA for a group matching game is at most kα …


Multimedia Content-Based Indexing And Recognition In Digital Libraries, Steven Medina Jan 2012

Multimedia Content-Based Indexing And Recognition In Digital Libraries, Steven Medina

Dissertations and Theses

"Recognition of digital media is more prevalent in today’s computer culture than ever before. The advent of low cost storage has created a seemingly infinite amount of metadata on the internet, as well as on local machines throughout the world. It is more important than ever to have the capability of quickly and accurately filtering this metadata to find a desired result. Data can be searched using various criteria. For example, text data is searched by analyzing the contents of the text itself. One might execute a search using a method as simple as looking for the ASCII file name, …


Parallel Trie-Based Frequent Itemset Mining On Graphics Processors, Jay Junjie Yao Jan 2012

Parallel Trie-Based Frequent Itemset Mining On Graphics Processors, Jay Junjie Yao

Dissertations and Theses

No abstract provided.


Developing A Comprehensive Software Toolkit For Creating Digital Mosaic Artwork, Dmitry Bosikov Jan 2012

Developing A Comprehensive Software Toolkit For Creating Digital Mosaic Artwork, Dmitry Bosikov

Dissertations and Theses

No abstract provided.


Rapid Decoding Of Digital Data Streams Using Field Programmable Gate Arrays, Andrew Hernandez Jan 2012

Rapid Decoding Of Digital Data Streams Using Field Programmable Gate Arrays, Andrew Hernandez

Dissertations and Theses

No abstract provided.