Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 55621 - 55650 of 63515

Full-Text Articles in Entire DC Network

Static Analysis Of Memory-Accessing Gestures In Java, Christopher R. Hill Mar 2004

Static Analysis Of Memory-Accessing Gestures In Java, Christopher R. Hill

All Computer Science and Engineering Research

We propose the notion of Java-program gestures that are composed of a series of memory-accessing instructions. By finding patterns in gestures whose execution can be atomic, we can load them in an intelligent memory controller. This process can improve performance of the Java Virtual Machine, decrease code footprint, and reduce power consumption in hardware. In this thesis we formally define a language of gestures and introduce a method of detecting them statically at compile-time. We introduce a simple heuristic for reducing the number of gestures that must be loaded into the memory controller and show that finding the minimum number …

Go to article

Design And Implementation Of A String Matching System For Network Intrusion Detection Using Fpga-Based Bloom Filters, Sarang Dharmapurikar, Michael Attig, John Lockwood Mar 2004

Design And Implementation Of A String Matching System For Network Intrusion Detection Using Fpga-Based Bloom Filters, Sarang Dharmapurikar, Michael Attig, John Lockwood

All Computer Science and Engineering Research

Modern Network Intrusion Detection Systems (NIDS) inspect the network packet payload to check if it conforms to the security policies of the given network. This process, of-ten referred to as deep packet inspection, involves detection of predefined signature strings or keywords starting at an arbitrary location in the payload. String matching is a computationally intensive task and can become a potential bottleneck without high-speed processing. Since the conventional software-implemented string matching algorithms have not kept pace with the increasing network speeds, special purpose hardware solutions have been introduced. In this paper we show how Bloom filters can be used effectively …

Go to article

Fast Registration Of Tabular Document Images Using The Fourier-Mellin Transform, Luke Alexander Daysh Hutchison Mar 2004

Fast Registration Of Tabular Document Images Using The Fourier-Mellin Transform, Luke Alexander Daysh Hutchison

Theses and Dissertations

Image registration, the process of finding the transformation that best maps one image to another, is an important tool in document image processing. Having properly-aligned microfilm images can help in manual and automated content extraction, zoning, and batch compression of images. An image registration algorithm is presented that quickly identifies the global affine transformation (rotation, scale, translation and/or shear) that maps one tabular document image to another, using the Fourier-Mellin Transform. Each component of the affine transform is recovered independantly from the others, dramatically reducing the parameter space of the problem, and improving upon standard Fourier-Mellin Image Registration (FMIR), which …

Go to article

A Subgroup Algorithm To Identify Cross-Rotation Peaks Consistent With Non-Crystallographic Symmetry, Ryan H. Lilien, Chris Bailey-Kellogg, Amy C. Anderson, Bruce R. Donald Mar 2004

A Subgroup Algorithm To Identify Cross-Rotation Peaks Consistent With Non-Crystallographic Symmetry, Ryan H. Lilien, Chris Bailey-Kellogg, Amy C. Anderson, Bruce R. Donald

Dartmouth Scholarship

Molecular replacement (MR) often plays a prominent role in determining initial phase angles for structure determination by X-ray crystallography. In this paper, an efficient quaternion-based algorithm is presented for analyzing peaks from a cross-rotation function in order to identify model orientations consistent with proper non-crystallographic symmetry (NCS) and to generate proper NCS-consistent orientations missing from the list of cross-rotation peaks. The algorithm, CRANS, analyzes the rotation differences between each pair of cross-rotation peaks to identify finite subgroups. Sets of rotation differences satisfying the subgroup axioms correspond to orientations compatible with the correct proper NCS. The CRANS algorithm was first …

Go to article

Ai In Computer Games: From The Player’S Goal To Ai’S Role, Jeremy A. Glasser, Leen-Kiat Soh Mar 2004

Ai In Computer Games: From The Player’S Goal To Ai’S Role, Jeremy A. Glasser, Leen-Kiat Soh

School of Computing: Technical Reports

This paper addresses the role of Artificial Intelligence (AI) in a variety of game genres. Every game aims to entertain (though educational games have secondary objectives). Each genre approaches entertainment in a unique way. We explore the methods used to draw the game player’s attention. We then consider how the AI interacts with the player to promote both entertainment and an interactive environment. We also consider some of the techniques that will shape tomorrow’s games. Included are opponent strategies, interactive environments, and multiagent systems (MAS). While different, each approach can aid in creating more immersive and challenging gaming experiences. Our …

Go to article

Prioritized Soft Constraint Satisfaction: A Qualitative Method For Dynamic Transport Selection In Heterogeneous Wireless Environments, Heidi R. Duffin, Michael A. Goodrich, Charles D. Knutson Mar 2004

Prioritized Soft Constraint Satisfaction: A Qualitative Method For Dynamic Transport Selection In Heterogeneous Wireless Environments, Heidi R. Duffin, Michael A. Goodrich, Charles D. Knutson

Faculty Publications

This paper presents Prioritized Soft Constraint Satisfaction (PSCS), a novel approach to selecting the “best” transport in dynamic wireless transport switching systems. PSCS maintains a satisfying connection to another endpoint by choosing transports based on a user-established range of preferences and priority for criteria such as speed, power, range and cost. Additionally, feedback is provided regarding tradeoffs among the criteria, thus enabling the user to adjust inputs according to the capabilities of the system. We also recommend guidelines for setting preferences and priorities.

Go to article

Dynamic Autonomous Transport Selection In Heterogeneous Wireless Environments, Jeffrey M. Brown, Heidi R. Duffin, Charles D. Knutson, Shannon B. Barnes, Ryan W. Woodings Mar 2004

Dynamic Autonomous Transport Selection In Heterogeneous Wireless Environments, Jeffrey M. Brown, Heidi R. Duffin, Charles D. Knutson, Shannon B. Barnes, Ryan W. Woodings

Faculty Publications

In this paper, we introduce Quality of Transport (QoT), an architecture for synergistically and autonomously managing session-layer protocol access to multiple transports in heterogeneous wireless environments. We present an overview of the QoT architecture including: 1) transport discovery, 2) service discovery, 3) object exchange, 4) transport switching, and 5) intelligent transport selection. Preliminary successes with our design and implementation of QoT suggest that dynamic intelligent autonomous transport switching can help to optimize user experience and session layer performance in multi-transport environments.

Go to article

The Changing Usage Of A Mature Campus-Wide Wireless Network, Tristan Henderson, David Kotz, Ilya Abyzov Mar 2004

The Changing Usage Of A Mature Campus-Wide Wireless Network, Tristan Henderson, David Kotz, Ilya Abyzov

Computer Science Technical Reports

Wireless Local Area Networks (WLANs) are now common on academic and corporate campuses. As ``Wi-Fi'' technology becomes ubiquitous, it is increasingly important to understand trends in the usage of these networks. This paper analyzes an extensive network trace from a mature 802.11 WLAN, including more than 550 access points and 7000 users over seventeen weeks. We employ several measurement techniques, including syslogs, telephone records, SNMP polling and tcpdump packet sniffing. This is the largest WLAN study to date, and the first to look at a large, mature WLAN and consider geographic mobility. We compare this trace to a trace taken …

Go to article

Evolution Of Control Programs For A Swarm Of Autonomous Unmanned Aerial Vehicles, Kevin M. Milam Mar 2004

Evolution Of Control Programs For A Swarm Of Autonomous Unmanned Aerial Vehicles, Kevin M. Milam

Theses and Dissertations

Unmanned aerial vehicles (UAVs) are rapidly becoming a critical military asset. In the future, advances in miniaturization are going to drive the development of insect size UAVs. New approaches to controlling these swarms are required. The goal of this research is to develop a controller to direct a swarm of UAVs in accomplishing a given mission. While previous efforts have largely been limited to a two-dimensional model, a three-dimensional model has been developed for this project. Models of UAV capabilities including sensors, actuators and communications are presented. Genetic programming uses the principles of Darwinian evolution to generate computer programs to …

Go to article

An Exploratory Analysis Of Factors Affecting Participation In Air Force Knowledge Now Communities Of Practice, David C. Fitzgerald Mar 2004

An Exploratory Analysis Of Factors Affecting Participation In Air Force Knowledge Now Communities Of Practice, David C. Fitzgerald

Theses and Dissertations

As the AF continues to lose its knowledge base through retirements and downsizing, the need to get maximum use from the remaining knowledge base becomes increasingly important. In their efforts to help the Department of Defense and the Air Force Chief Information Officer (AFCIO) meet their knowledge management goals, Air Force Material Command (AFMC) has been working to implement the use of communities of practice. A primary goal of AFMC/DRW , the AF Knowledge Now program office, and the office of the AFCIO is to increase effectiveness and participation within communities of practice. The goal of this research is to …

Go to article

Parallel Out-Of-Core Sorting: The Third Way, Geeta Chaudhry Mar 2004

Parallel Out-Of-Core Sorting: The Third Way, Geeta Chaudhry

Dartmouth College Ph.D Dissertations

Sorting very large datasets is a key subroutine in almost any application that is built on top of a large database. Two ways to sort out-of-core data dominate the literature: merging-based algorithms and partitioning-based algorithms. Within these two paradigms, all the programs that sort out-of-core data on a cluster rely on assumptions about the input distribution. We propose a third way of out-of-core sorting: oblivious algorithms. In all, we have developed six programs that sort out-of-core data on a cluster. The first three programs, based completely on Leighton's columnsort algorithm, have a restriction on the maximum problem size that they …

Go to article

Development Approaches Coupled With Verification And Validation Methodologies For Agent-Based Mission-Level Analytical Combat Simulations, Lance E. Champagne Mar 2004

Development Approaches Coupled With Verification And Validation Methodologies For Agent-Based Mission-Level Analytical Combat Simulations, Lance E. Champagne

Theses and Dissertations

This research investigated the applicability of agent-based combat simulations to real-world combat operations. An agent-based simulation of the Allied offensive search for German U-Boats in the Bay of Biscay during World War II was constructed, extending the state-of-the-art in agent-based combat simulations, bridging the gap between the current level of agent-like combat simulations and the concept of agent-based simulations found in the broader literature. The proposed simulation advances agent-based combat simulations to “validateable” mission-level military operations. Simulation validation is a complex task with numerous, diverse techniques available and levels of validation differing significantly among simulations and applications. This research presents …

Go to article

Exploring Content Management Issues In Air Force On-Line Communities Of Practice: A Multiple Case Study Approach, Jaime A. Rodriguez Mar 2004

Exploring Content Management Issues In Air Force On-Line Communities Of Practice: A Multiple Case Study Approach, Jaime A. Rodriguez

Theses and Dissertations

The practice of content management attempts regardless of platform to ensure that pertinent information is current, relevant, and presented in a usable manner. The Air Force Communities of Practice (CoPs) are hosted by AFMC/DRW, The purpose of these CoPs is to facilitate and promote an environment of capturing and sharing knowledge among members of a particular field task or common practice. As the host for these CoPs AFMC/DRW desires to increase CoP participation efficiency and effectiveness. Addressing existing or potential content management issues will help do so. This multiple-case study research observed and interviewed managers and members of eight active …

Go to article

An Exploration Of Cultural Factors Affecting Use Of Communities Of Practice, Peter L. Hinrichsen Mar 2004

An Exploration Of Cultural Factors Affecting Use Of Communities Of Practice, Peter L. Hinrichsen

Theses and Dissertations

On-line communities of practice are potentially powerful social learning networks that can improve organizational performance. Unfortunately, administrators of on-line communities of practice report that community members do not take full advantage of this potential. This study used Shaw and Tuggle's (2003) factors of knowledge management (KM) culture affecting organizational acceptance of a knowledge management initiative to explore this issue. It was hypothesized that respondents whose communities of practice possessed higher average community use per member would rate KM culture variables higher than respondents whose communities possessed a lower average community use. An analysis of survey data collected from Air Force …

Go to article

Service Oriented Computing Imperatives In Ad Hoc Wireless Settings, Rohan Sen, Radu Handorean, Gruia-Catalin Roman, Christopher Gill Mar 2004

Service Oriented Computing Imperatives In Ad Hoc Wireless Settings, Rohan Sen, Radu Handorean, Gruia-Catalin Roman, Christopher Gill

All Computer Science and Engineering Research

Service oriented computing is a new paradigm that is gaining popularity in dis-tributed computing environments due to its emphasis on highly specialized, modular and platform-agnostic code facilitating interoperability of systems. It borrows concepts from more mature paradigms such as object-oriented and component computing. This results in a progression from object-oriented computing to component computing and finally to service oriented computing, a new paradigm for designing and delivering software. Just as an object encapsulates state and behavior at a fine level of granularity, a service offers similar encapsulation at a larger scale. This evolution raises the level of abstraction at which …

Go to article

Identification Of Novel Small Molecule Inhibitors Of Core-Binding Factor Dimerization By Computational Screening Against Nmr Molecular Ensemble, Ryan H. Lilien, Mohini Sridharan, Bruce R. Donald Mar 2004

Identification Of Novel Small Molecule Inhibitors Of Core-Binding Factor Dimerization By Computational Screening Against Nmr Molecular Ensemble, Ryan H. Lilien, Mohini Sridharan, Bruce R. Donald

Computer Science Technical Reports

The long development process of novel pharmaceutical compounds begins with the identification of a lead inhibitor compound. Computational screening to identify those ligands, or small molecules, most likely to inhibit a target protein may benefit the pharmaceutical development process by reducing the time required to identify a lead compound. Typically, computational ligand screening utilizes high-resolution structural models of both the protein and ligand to fit or `dock' each member of a ligand database into the binding site of the protein. Ligands are then ranked by the number and quality of interactions formed in the predicted protein-ligand complex. It is currently …

Go to article

Automating Security Protocol Analysis, Stephen W. Mancini Mar 2004

Automating Security Protocol Analysis, Stephen W. Mancini

Theses and Dissertations

When Roger Needham and Michael Schroeder first introduced a seemingly secure protocol 24, it took over 18 years to discover that even with the most secure encryption, the conversations using this protocol were still subject to penetration. To date, there is still no one protocol that is accepted for universal use. Because of this, analysis of the protocol outside the encryption is becoming more important. Recent work by Joshua Guttman and others 9 have identified several properties that good protocols often exhibit. Termed Authentication Tests, these properties have been very useful in examining protocols. The purpose of this research is …

Go to article

The Evolution Of Research On Information Systems: A Fiftieth Year Survey Of The Literature In Management Science, Rajiv D. Banker, Robert J. Kauffman Mar 2004

The Evolution Of Research On Information Systems: A Fiftieth Year Survey Of The Literature In Management Science, Rajiv D. Banker, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

The development of the information systems (IS) literature in Management Science during the past 50 years reflects the inception, growth, and maturation of several different research streams. The five research streams we identify incorporate different definitions of the managerial problems that relate to IS, the alternate theoretical perspectives and different methodological paradigms to study them, and the levels of the organization at which their primary results impact managerial practice. The decision support and design science research stream studies the application of computers in decision support, control, and managerial decision making. The value of information research stream reflects relationships established based …

Go to article

Tool Support For Model Based Architectural Design For Automotive Control Systems, Kevin Steppe Mar 2004

Tool Support For Model Based Architectural Design For Automotive Control Systems, Kevin Steppe

Research Collection School Of Computing and Information Systems

In conjunction with Ford Motor Company, we built a tool to support multilevel architectural design. The tool, called Synergy, allows Ford to visually design architectures of vehicle control components. The components are imported from existing Simulink models; then the tool automatically generates a detailed view showing all required connections and ports. The resulting model is exported to Simulink for further analysis. In this paper we describe the conceptual and technical challenges encountered in building Synergy and our design choices for solving them.

Go to article

Corollaries On The Fixpoint Completion: Studying The Stable Semantics By Means Of The Clark Completion, Pascal Hitzler Mar 2004

Corollaries On The Fixpoint Completion: Studying The Stable Semantics By Means Of The Clark Completion, Pascal Hitzler

Computer Science and Engineering Faculty Publications

The fixpoint completion fix (P) of a normal logic program P is a program transformation such that the stable models of P are exactly the models of the Clark completion of fix (P). This is well-known and was studied by Dung and Kanchanasut [15]. The correspondence, however, goes much further: The Gelfond-Lifschitz operator of P coincides with the immediate consequence operator of fix (P), as shown by Wendt [51], and even carries over to standard operators used for characterizing the well-founded and the Kripke-Kleene semantics. We will apply this knowledge to the study of …

Go to article

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 5, March 2004, College Of Engineering And Computer Science, Wright State University Mar 2004

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 5, March 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Go to article

A Meeting Detector And Its Applications, Jue Wang, Guanling Chen, David Kotz Mar 2004

A Meeting Detector And Its Applications, Jue Wang, Guanling Chen, David Kotz

Computer Science Technical Reports

In this paper we present a context-sensing component that recognizes meetings in a typical office environment. Our prototype detects the meeting start and end by combining outputs from pressure and motion sensors installed on the chairs. We developed a telephone controller application that transfers incoming calls to voice-mail when the user is in a meeting. Our experiments show that it is feasible to detect high-level context changes with ``good enough'' accuracy, using low-cost, off-the-shelf hardware, and simple algorithms without complex training. We also note the need for better metrics to measure context detection performance, other than just accuracy. We propose …

Go to article

Dependency Management In Distributed Settings, Guanling Chen, David Kotz Mar 2004

Dependency Management In Distributed Settings, Guanling Chen, David Kotz

Computer Science Technical Reports

Ubiquitous-computing environments are heterogeneous and volatile in nature. Systems that support ubicomp applications must be self-managed, to reduce human intervention. In this paper, we present a general service that helps distributed software components to manage their dependencies. Our service proactively monitors the liveness of components and recovers them according to supplied policies. Our service also tracks the state of components, on behalf of their dependents, and may automatically select components for the dependent to use based on evaluations of customized functions. We believe that our approach is flexible and abstracts away many of the complexities encountered in ubicomp environments. In …

Go to article

Swarm Based Implementation Of A Virtual Distributed Database System In A Sensor Network, Wen C. Lee Mar 2004

Swarm Based Implementation Of A Virtual Distributed Database System In A Sensor Network, Wen C. Lee

Theses and Dissertations

The deployment of unmanned aerial vehicles (UAVs) in recent military operations has had success in carrying out surveillance and combat missions in sensitive areas. An area of intense research on UAVs has been on controlling a group of small-sized UAVs to carry out reconnaissance missions normally undertaken by large UAVs such as Predator or Global Hawk. A control strategy for coordinating the UAV movements of such a group of UAVs adopts the bio-inspired swarm model to produce autonomous group behavior. This research proposes establishing a distributed database system on a group of swarming UAVs, providing for data storage during a …

Go to article

Automated Agent Ontology Creation For Distributed Databases, Austin A. Bartolo Mar 2004

Automated Agent Ontology Creation For Distributed Databases, Austin A. Bartolo

Theses and Dissertations

In distributed database environments, the combination of resources from multiple sources requiring different interfaces is a universal problem. The current solution requires an expert to generate an ontology, or mapping, which contains all interconnections between the various fields in the databases. This research proposes the application of software agents in automating the ontology creation for distributed database environments with minimal communication. The automatic creation of a domain ontology alleviates the need for experts to manually map one database to other databases in the environment. Using several combined comparison methods, these agents communicate and negotiate similarities between information sources and retain …

Go to article

An Analysis Of The Performance And Security Of J2sdk 1.4 Jsse Implementation Of Ssl/Tls, Danny R. Bias Mar 2004

An Analysis Of The Performance And Security Of J2sdk 1.4 Jsse Implementation Of Ssl/Tls, Danny R. Bias

Theses and Dissertations

The Java SSL/TLS package distributed with the J2SE 1.4.2 runtime is a Java implementation of the SSLv3 and TLSv1 protocols. Java-based web services and other systems deployed by the DoD will depend on this implementation to provide confidentiality, integrity, and authentication. Security and performance assessment of this implementation is critical given the proliferation of web services within DoD channels. This research assessed the performance of the J2SE 1.4.2 SSL and TLS implementations, paying particular attention to identifying performance limitations given a very secure configuration. The performance metrics of this research were CPU utilization, network bandwidth, memory, and maximum number of …

Go to article

Software Development Outsourcing Decision Support Tool With Neural Network Learning, James D. Newberry Mar 2004

Software Development Outsourcing Decision Support Tool With Neural Network Learning, James D. Newberry

Theses and Dissertations

The Air Force (AF) needs an evolving software tool for guiding decision makers through the complexities of software outsourcing. Previous research identified specific outsourcing strategies and linked them to goals and consequences through a variety of relationship rules. These strategies and relationship rules were inserted into a decision support tool. Since that time, more historical data and outsourcing literature has been collected thus necessitating an update to such a tool. As the number of software outsourcing projects are completed, the AF must capture the outsourcing decision experiences which guided the projects and their outcomes. In order to efficiently incorporate this …

Go to article

Netwars Based Study Of A Joint Stars Link-16 Network, Charlie I. Cruz Mar 2004

Netwars Based Study Of A Joint Stars Link-16 Network, Charlie I. Cruz

Theses and Dissertations

Both secure and anti-jam resistant, the Link-16 is the primary communications channel used by the Joint Surveillance Target Attack Radar System (Joint STARS) for the exchange of real-time tactical data among various ground, air, and sea platforms of the United States of America and North Atlantic Treaty Organization forces. This research explored the effect of increasing network traffic for imagery transfer to the mean delay when operating under different network topologies. Using Network Warfare Simulation (NETWARS), three different missions were simulated to run on five network topologies having a different number of participants, different assigned time slots, and stacked nets. …

Go to article

Intelligent Query Answering Through Rule Learning And Generalization, James M. Carsten Mar 2004

Intelligent Query Answering Through Rule Learning And Generalization, James M. Carsten

Theses and Dissertations

The Department of Defense (DoD) relies heavily on information systems to complete a myriad of tasks, from day-to-day personnel actions to mission critical imagery retrieval, intelligence analysis, and mission planning. The astronomical growth in size and performance of data storage systems leads to problems in processing the amount of data returned on any given query. Typical relational database systems return a set of unordered records. This approach is acceptable in small information systems, but in large systems, such as military image retrieval systems with more than 1 million records, it requires considerable time (often hours to days) to sort through …

Go to article

Concurrent Cognitive Mapping And Localization Using Expectation Maximization, Kennard R. Laviers Mar 2004

Concurrent Cognitive Mapping And Localization Using Expectation Maximization, Kennard R. Laviers

Theses and Dissertations

Robot mapping remains one of the most challenging problems in robot programming. Most successful methods use some form of occupancy grid for representing a mapped region. An occupancy grid is a two dimensional array in which the array cells represents (x,y) coordinates of a cartesian map. This approach becomes problematic in mapping large environments as the map quickly becomes too large for processing and storage. Rather than storing the map as an occupancy grid, our robot (equipped with ultrasonic sonars) views the world as a series of connected spaces. These spaces are initially mapped as an occupancy grid in a …

Go to article

First Prev Next Last