Computer Sciences Commons^™

Consistency Management Among Replicas In Peer-To-Peer Mobile Ad Hoc Networks, Sanjay Kumar Madria, Takahiro Hara

Computer Science Faculty Research & Creative Works

Recent advances in wireless communication along with peer-to-peer (P2P) paradigm have led to increasing interest in P2P mobile ad hoc networks. In this paper, we assume an environment where each mobile peer accesses data items held by other peers which are connected by a mobile ad hoc network. Since peers' mobility causes frequent network partitions, replicas of a data item may be inconsistent due to write operations performed by mobile peers. In such an environment, the global consistency of data items is not desirable by many applications. Thus, new consistency maintenance based on local conditions such as location and time …

Adaptive Replication And Access Control Of Multimedia Data In A P2p Environment, Sanjay Kumar Madria, Sanjeev Agarwal

Computer Science Faculty Research & Creative Works

This paper explores some of the ideas and solutions related to replication and access control of multimedia data in a hierarchical P2P environment. We provided overview of the techniques to generate multiresolution of multimedia data and explored error recovery and access control issues.

Biologically Inspired Learning System, Patrick Mcdowell

LSU Doctoral Dissertations

Learning Systems used on robots require either a-priori knowledge in the form of models, rules of thumb or databases or require that robot to physically execute multitudes of trial solutions. The first requirement limits the robot’s ability to operate in unstructured changing environments, and the second limits the robot’s service life and resources. In this research a generalized approach to learning was developed through a series of algorithms that can be used for construction of behaviors that are able to cope with unstructured environments through adaptation of both internal parameters and system structure as a result of a goal based …

Jess – A Java Security Scanner For Eclipse, Russell Spitler

Honors Theses

Secure software is the responsibility of every developer. In order to help a developer with this responsibility there are many automated source code security auditors. These tools perform a variety of functions, from finding calls to insecure functions to poorly generated random numbers. These programs have existed for years and perform the security audit with varying degrees of success.

Largely missing in the world of programming is such a security auditor for the Java programming language. Currently, Fortify Software produces the only Java source code security auditor; this is a commercially available package.

This void is what inspired JeSS, Java …

Unpredictable Binary Strings, Richard Low, Mark Stamp, R. Craigen, G. Faucher

Faculty Publications, Computer Science

We examine a class of binary strings arising from considerations about stream cipher encryption: to what degree can one guarantee that the number of pairs of entries distance k apart that disagree is equal to the number that agree, for all small k? In a certain sense, a keystream with such a property achieves a degree of unpredictability. The problem is also restated combinatorially in terms of seating arrangements. We examine sequences s of length 2n in which this property holds for all k ≤ Mn, where Mn is the largest number for which this is possible among strings of …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 4, January 2005, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Disjunctive Answer Set Programming Via Satisfiability, Yuliya Lierler

Computer Science Faculty Proceedings & Presentations

Using SAT solvers as inference engines in answer set programming systems showed to be a promising approach in building efficient systems. Nowadays SAT based answer set programming systems successfully work with nondisjunctive programs. This paper proposes a way to use SAT solvers for finding answer sets for disjunctive logic programs. We implement two different ways of SAT solver invocation used in nondisjunctive answer set programming. The algorithms are based on the definition of completion for disjunctive programs and the extension of loop formula to the disjunctive case. We propose the necessary modifications to the algorithms known for nondisjunctive programs in …

Fly Through A Pig's Heart, Thomas Wischgoll

Computer Science and Engineering Faculty Publications

This exhibit enables you to go on a fantastic voyage through the blood stream. Based on a scan of a real pig’s heart the arterial blood vessels were modeled allowing you to navigate through the vascular system of this heart and explore the blood and its different particles.

The Interior Of A Pig's Heart: A Museum Exhibit, Thomas Wischgoll, Joerg Meyer

Computer Science and Engineering Faculty Publications

Coronary heart diseases (CHD) are one of the primary causes of deaths in the United States. It is commonly accepted that certain factors, such as a cholesterol high diet, increase the risk of coronary heart diseases. As a consequence, people should be educated to adhere a diet low in low-density lipoprotein (LDL or bad cholesterol). ln order for children to become familiar with these facts, educational computer games can be employed to raise some awareness. This poster describes an educational museum exhibit that serves this purpose. ln a game-like environment, children can practice their navigation skills, while learning about the …

A Generative Programming Approach To Interactive Information Retrieval: Insights And Experiences, Saverio Perugini, Naren Ramakrishnan

Computer Science Faculty Publications

We describe the application of generative programming to a problem in interactive information retrieval. The particular interactive information retrieval problem we study is the support for "out-of-turn interaction" with a website – how a user can communicate input to a website when the site is not soliciting such information on the current page, but will do so on a subsequent page. Our solution approach makes generous use of program transformations (partial evaluation, currying, and slicing) to delay the site’s current solicitation for input until after the user’s out-of-turn input is processed. We illustrate how studying out-of-turn interaction through a generative …

Recommender Systems Research, Saverio Perugini

Computer Science Faculty Publications

We outline the history of recommender systems from their roots in information retrieval and filtering to their role in today’s Internet economy. Recommender systems attempt to reduce information overload and retain customers by selecting a subset of items from a universal set based on user preferences. Research in recommender systems lies at the intersection of several areas of computer science, such as artificial intelligence and human-computer interaction, and has progressed to an important research area of its own. It is important to note that recommendations are not delivered within a vacuum, but rather cast within an informal community of users …

The Good, Bad And The Indifferent: Explorations In Recommender System Health, Benjamin J. Keller, Sun-Mi Kim, N. Srinivas Vemuri, Naren Ramakrishnan, Saverio Perugini

Computer Science Faculty Publications

Our work is based on the premise that analysis of the connections exploited by a recommender algorithm can provide insight into the algorithm that could be useful to predict its performance in a fielded system. We use the jumping connections model defined by Mirza et al. [6], which describes the recommendation process in terms of graphs. Here we discuss our work that has come out of trying to understand algorithm behavior in terms of these graphs. We start by describing a natural extension of the jumping connections model of Mirza et al., and then discuss observations that have come from …

The Multiple Roles Of Anticipation In Developmental Robotics, Doug Blank, Joshua M. Lewis, James B. Marshall

Computer Science Faculty Research and Scholarship

Anticipatory systems have been shown to be useful in discrete, symbolic systems. However, non­symbolic anticipatory systems are less well understood. In this paper, we explore the use of anticipation within the framework of connectionist networks to bootstrap from an innate behavior; to drive a reinforcement signal; and to provide feedback on the learnability of a task.

A Context-Dependent Model Of Proximity In Physically Situated Environments, John D. Kelleher, Geert-Jan M. Kruijff

Conference papers

The paper presents a computational model for a context-dependent analysis of a physical environment in terms of spatial proximity. The model provides a basis for grounding linguistic analyses of spatial expressions in visual perception. The model uses potential fields to model spatial proximity. It has been implemented, and when combined with a handcrafted grammar, is used to enable a conversational robot to carry out a situated dialogue with a human. The key concept in our approach is defining the region that is proximal to a landmark based on the spatial configuration of other objects in the scene. The model extends …

Design, Simulation And Tests Of A Low-Cost Microstrip Patch Antenna Arrays For The Wireless Communication, Gonca Çakir, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Typical low-cost, low-weight microstrip base station antenna arrays with beam-scanning capabilities are taken into account. In downtowns of large cities like New York, Chicago, and in historical cities like Istanbul, where high buildings are separated by narrow but densely occupied streets, antenna arrays with approximately 20°-35° beam-widths are required to complete the cellular communication coverage. To meet this requirement, new antenna arrays are designed with 35° beam-widths and 60° electronic scanning capabilities. Their characteristics are investigated both numerically and experimentally. An FDTD-based antenna simulation package (M-PATCH) is prepared, tested on canonical structures and against the literature first, for verification and …

Soft Computing Methods In Microwave Active Device Modeling, Yavuz Cengi̇z, Fi̇li̇z Güneş, Mehmet Fati̇h Çağlar

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, the signal and noise behaviors of a microwave transistor within its operation domain (CT,V_{DS}, I_{DS}, f) are modeled by the Artificial Neural Network (ANN) and Fuzzy Logic System (FLS) without using any information on the microwave circuit theory . A worked example is presented where the same data is employed for both models selected from the manufacturer's data sheets. Performances of the FLS and ANN models are compared and conclusions are drawn.

Fault Tolerant Control With Re-Configuring Sliding-Mode Schemes, Ufuk Demi̇rci̇, Feza Kerestecioğlu

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a controller design method for linear MIMO systems is presented which a sliding mode controller is reconfigured in case of system faults. Faults are detected with the residual vector generated from a standard linear observer. Once a fault has been detected the fault distribution matrix can be obtained and used to update the corrective or equivalent control parts of the sliding mode controller. As a result, fault tolerant adaptive controllers keep the system performance within acceptable limits or at least avoids the system to wind-up.

Computation Of Association Probabilities For Single Target Tracking With The Use Of Adaptive Neuro-Fuzzy Inference System, İlke Türkmen, Keri̇m Güney

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a simple method based on the adaptive neuro-fuzzy inference system (ANFIS) is presented for computing the association probabilities. The computed association probabilities are used to track the single manoeuvring target in the cluttered environment. A hybrid learning algorithm, which combines the least square method and the backpropagation algorithm, is used to identify the parameters of ANFIS. The tracks estimated by using the method proposed in this study are in very good agreement with the true tracks. Better accuracy with respect to the well known nearest neighbour Kalman filter and probabilistic data association algorithms is obtained.

Silhouette Based Human Motion Detection And Analysis For Real-Time Automated Video Surveillance, Murat Eki̇nci̇, Eyüp Gedi̇kli̇

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a real-time background modeling and maintenance based human motion detection and analysis in an indoor and an outdoor environments for visual surveillance system is described. The system operates on monocular gray scale video imagery from a static CCD camera. In order to detect foreground objects, first, background scene model is statistically learned using the redundancy of the pixel intensities in a training stage, even the background is not completely stationary. This redundancy information of the each pixel is separately stored in an history map shows how the pixel intensity values changes till now. Then the highest ratio …

Future Reasoning Machines: Mind And Body, Brian Duffy, Gregory O'Hare, John Bradley, Bianca Schoen-Phelan

Articles

In investing energy in developing reasoning machines of the future, one must abstract away from the specific solutions to specific problems and ask what are the fundamental research questions that should be addressed. This paper aims to revisit some fundamental perspectives and promote new approaches to reasoning machines and their associated form and function. Core aspects are discussed, namely the one-mind-many-bodies metaphor as introduced in the Agent Chameleon work. Within this metaphor the agent’s embodiment form may take many guises with the artificial mind or agent potentially exhibiting a nomadic existence opportunistically migrating between a myriad of instantiated embodiments. We …

Evaluating Particle Swarm Intelligence Techniques For Solving University Examination Timetabling Problems, Daniel R. Fealko

CCAC Theses and Dissertations

The purpose of this thesis is to investigate the suitability and effectiveness of the Particle Swarm Optimization (PSO) technique when applied to the University Examination Timetabling problem. We accomplished this by analyzing experimentally the performance profile-the quality of the solution as a function of the execution time-of the standard form of the PSO algorithm when brought to bear against the University Examination Timetabling problem. This study systematically investigated the impact of problem and algorithm factors in solving this particular timetabling problem and determined the algorithm's performance profile under the specified test environment. Keys factors studied included problem size (i.e., number …

Establishing An Online Community Of Practice For Instructors Of English As A Foreign Language, Christopher M. Johnson

CCAC Theses and Dissertations

Communities of practice are entities that emerge for the purposes of learning and advancement of knowledge in a particular area. They emerge under all circumstances, even adverse situations. Because they can spawn great innovation and knowledge advancement, organizations need to cultivate and establish environments that allow them to develop. Currently, communities of practice have moved into the online world, in which their members use computer mediated communication to collaborate with each other.

In January, 2002, a virtual community was formed to enable teachers of English as a Foreign Language to collaborate on learning and applying various computing technologies in language …

A Self-Adaptive Evolutionary Negative Selection Approach For Anomaly Detection, Luis J. Gonzalez

CCAC Theses and Dissertations

Forrest et al. (1994; 1997) proposed a negative selection algorithm, also termed the exhaustive detector generating algorithm, for various anomaly detection problems. The negative selection algorithm was inspired by the thymic negative selection process that is intrinsic to natural immune systems, consisting of screening and deleting self-reactive T-cells, i.e., those T-cells that recognize self-cells.

The negative selection algorithm takes considerable time (exponential to the size of the self-data) and produces redundant detectors. This time/size limitation motivated the development of different approaches to generate the set of candidate detectors.

A reasonable way to find suitable parameter settings is to let an …

A Study Of The Relationships Between End-User Information Systems Problems And Helpdesk Critical Success Factors In Higher Education, Richard Dale Parrott

CCAC Theses and Dissertations

In the last fifteen years, information technology (IT) customer support has increased in importance within higher education. The pervasiveness of computers and technology on the campus has allowed students, staff, and faculty to perform a multitude of tasks by controlling their own environments and setting their own priorities. Qualified professional system and user support services have lagged demand. The problem investigated in this study was end-users' satisfaction levels of the higher education helpdesk and how end-users' satisfaction levels affected a helpdesk manager's critical success factors performance and goals. In this study, the first goal was to identify the critical success …

The Kerf Toolkit For Intrusion Analysis, Javed Aslam, Sergey Bratus, David Kotz, Ronald Peterson

Dartmouth Scholarship

No abstract provided.

Impacts Of Distributed Generators On The Oscillatory Stability Of Interconnected Power Systems, İstemi̇han Genç, Ömer Usta

Turkish Journal of Electrical Engineering and Computer Sciences

Integration of distributed generation is continually and gradually affecting the stability of interconnected power systems. In this paper, the impacts of distributed synchronous generators on oscillatory stability are studied. In various parameter sub-spaces of interest, feasibility regions can be calculated to determine the conditions to sustain the stable operation of an interconnected power system. Through computations of the feasibility boundaries corresponding to Hopf bifurcations of electromechanical oscillatory modes, we determine the operating limits for a stable operation of the system under small and continual disturbances such as predictable changes in loading conditions of generators. Thus, with the case studies given …

Sigma-Delta Voltage To Frequency Converter With Phase Modulation Possibility, Milan Stork

Turkish Journal of Electrical Engineering and Computer Sciences

Voltage to frequency converter (VFC) is an oscillator whose frequency is linearly proportional to control voltage. There are two common VFC architectures: the current steering multivibrator and the charge-balance VFC. For higher linearity, the charge-balancing method is preferred. The charge balanced VFC may be made in asynchronous or synchronous (clocked) forms. The synchronous charge balanced VFC or "sigma delta" (\Sigma-\Delta) VFC is used when output pulses are synchronized to a clock. The charge balance VFC is more complex, more demanding in its supply voltage and current requirements, and more accurate. It is capable of 16 to18 bit linearity. In this …

An Algorithm For Image Clustering And Compression, Meti̇n Kaya

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new approach to image compression based on fuzzy clustering. This new approach includes pre-filtering, and fuzzy logic image enhancing to reduce undesirable noise effects on segmentation result; separation of image into 4x4 blocks and two dimensional discrete cosine transform; obtaining of peak values of cosine membership functions by combining of performing the zig-zag method with discrete cosine transform coefficients; obtaining of membership values and cluster centroids; and finally, creation of segmented image and compression. After applying the new method on sample images at different number of clusters, better compression ratio, performing time and good validity measure …

Neighborhood Interchangeability And Dynamic Bundling For Non-Binary Csps, Anagh Lal, Berthe Y. Choueiry, Eugene C. Freuder

School of Computing: Conference and Workshop Papers

1. Interchangeability: An algorithm for computing interchangeability in non-binary CSPs.

2. Dynamic bundling: Integration of the above with backtrack search for solving non-binary CSPs.

3. Experiments demonstrating the benefits of dynamic bundling

·Finding multiple, robust solutions.

·Decreasing computational cost of search.

Neighborhood Interchangeability And Dynamic Bundling For Non-Binary Finite Csps, Anagh Lal, Berthe Y. Choueiry, Eugene C. Freuder

School of Computing: Conference and Workshop Papers

Neighborhood Interchangeability (NI) identifies the equivalent values in the domain of a variable of a Constraint Satisfaction Problem (CSP) by considering only the constraints that directly apply to the variable. Freuder described an algorithm for efficiently computing NI values in binary CSPs. In this paper, we show that the generalization of this algorithm to non-binary CSPs is not straightforward, and introduce an efficient algorithm for computing NI values in the presence of non-binary constraints. Further, we show how to interleave this mechanism with search for solving CSPs, thus yielding a dynamic bundling strategy. While the goal of dynamic bundling is …