Computer Sciences Commons^™

An All-To-All Multicast Routing Protocol In A Wireless Ad-Hoc Network To Improve Channel Utilization, Zhong Hua Zhou

Theses and Dissertations

Wireless Ad-hoc network has become more and more popular. Several different multicasting schemes for this type of network have been developed. But most of them are targeting a situation where the total number of senders is much less than the total number of receivers. This thesis analyzes different wireless communication patterns in ad hoc network, the trend for wireless communication and presents a new multicast scheme. It targets an ad-hoc network where all mobile hosts act as both senders and receivers. The proposed scheme in this thesis will reduce overheads by combining data packets that are destined for the same …

A Data Layout Descriptor Language (Ladel)., Ashfaq Ahmed Jeelani

Electronic Theses and Dissertations

To transfer data between devices and main memory, standard C block I/O interfaces use block buffers of type char. C++ programs that perform block I/O commonly use typecasting to move data between structures and block buffers. The subject of this thesis, the layout description language (LADEL), represents a high-level solution to the problem of block buffer management. LADEL provides operators that hide the casting ordinarily required to pack and to unpack buffers and guard against overflow of the virtual fields. LADEL also allows a programmer to dynamically define a structured view of a block buffer's contents. This view includes the …

Integration Of Student Academic Record And Major Requirements Through Xml., Zhujun Hou

Electronic Theses and Dissertations

The purpose of this thesis is to develop a software application based on previous studies by 1997 Oak Ridge Design Studio Team that matches students' progress with major requirements in their college career. This study addresses the problems of previous studies and suggests a solution. A powerful new technique, XML, is used to model, store and process the data of major requirements and student records. This application produces an HTML file that provides detailed information of a student's academic progress towards graduation.

On Defending Against Distribtued Denial- Of-Service Attacks With Server-Centric Router Throttles, David K.Y. Yau, Feng Liang, John C. S. Lui

Department of Computer Science Technical Reports

No abstract provided.

Search Behavior In A Research Oriented Digital Library, Malika Mahoui, Sally Jo Cunningham

Department of Computer Science Technical Reports

No abstract provided.

Idmp-Based Fast Handoffs And Paging In Ip-Based Cellular Networks, Archan Misra, Subir Das, Ashutosh Dutta, Sajal K. Das

Research Collection School Of Computing and Information Systems

We consider the use of our previously proposed Intra-Domain Mobility Management Protocol (IDMP) in fourth-generation mobile networks. On evaluating the heterogeneous access technologies, cellular layouts, and application characteristics of 4G environments, we realize a need to reduce both handoff latency and the frequency of mobility-related signaling. We first present IDMP's fast intradomain handoff mechanism that uses a duration-limited proactive packet multicasting solution. We quantify the expected buffering requirements of our proposed multicasting scheme for typical 4G network characteristics and compare it with alternative IP-based fast handoff solutions. We also present a paging scheme under IDMP that replicates the current cellular …

Quantitative Analysis Of Domain Testing Effectiveness., Narendra Koneru

Electronic Theses and Dissertations

The criticality of the applications modeled by the real-time software places stringent requirements on software quality before deploying into real use. Though automated test tools can be used to run a large number of tests efficiently, the functionality of any test tool is not complege without providing a means for analyzing the test results to determine potential problem sub-domains and sub-domains that need to be covered, and estimating the reliability of the modeled system.

This thesis outlines a solution strategy and implementation of that strategy for deriving quantitative metrics from domain testing of real-time control software tested via simulation. The …

Effective Bandwidth For Traffic Engineering, Mark J. Clement, Rob Kunz, Seth Nielson, Quinn O. Snell

Faculty Publications

In today’s Internet, demand is increasing for guarantees of speed and efficiency. Current routers are very limited in the type and quantity of observed data they can provide, making it difficult for providers to maximize utilization without the risk of degraded throughput. This research uses statistical data currents provided by router vendors to estimate the impact of changes in network configuration on the probability of link overflow. This allows service providers to calculate in advance, the effect of grooming on a network, eliminating the conservative trial-and-error approach normally used. These predictions are made using Large Deviation Theory, which focuses on …

Comparison Of Two Distributed Fuzzy Logic Controllers For Flexible-Link Manipulators, Linda Z. Shi, Mohamed Trabia

Mechanical Engineering Faculty Presentations

The paper suggests that fuzzy logic controllers present a computationally efficient and robust alternative to conventional controllers. The paper presents two possible structures for the distributed fuzzy logic controller of a single-link flexible manipulator. A linear quadratic regulator method is used to prove the effectiveness of fuzzy logic controllers.

The Next Wave In Erp Implementation, Keng Siau, Y. Tian

Research Collection School Of Computing and Information Systems

Although the benefits of ERP are obvious, the risks and costs associated with it are very high. Some problems in implementing ERP system are documented, but the real challenge comes from the Internet and E-business. ERP is an enterprise wide system whose purpose is to achieve internal efficiency, while E-business cuts across different enterprises and extends the individual value chain into an Internet based, dynamic process aimed at maximizing external efficiency. To survive the E-business challenge, the arguably single, and also the best, solution for ERP systems is to integrate with E-business applications, which we call ERP II. By properly …

Leveraging Test Measurements Into Proposing Additional Domain Tests., Radhika Turlapati

Electronic Theses and Dissertations

Accuracy and efficiency are extremely critical factors for large real-time control applications. A small oversight can cause catastrophic failure of a real-time system. Thus, these applications have to be tested meticulously to prevent any catastrophe that might occur. But, testing these applications exhaustively is not tractable, mainly due to the inherent complexity of the applications and also the huge amount of inputs and outputs that these applications involve. In order to save valuable amounts of time and resources, automated testing is imperative. Also, quantitative metrics have to be provided that assess the existing quality of the system and help increase …

Distribution List Maker Program With Inter-User Capabilities Between Universities And Colleges In The Tennessee Board Of Regents School System., Allan Richard Anderson

Electronic Theses and Dissertations

E-mail is an important tool for faculty and staff at the university, college, department, and instructor levels. E-mail is a useful medium in the academic setting for corresponding at all levels. Instructors e-mail students about assignments, lectures, and urgent information: for example, postponed classes and changes in the schedule. In addition e-mail is used to let potential students know about job opportunities. Other routine uses for e-mail include group communications within academic committees and groups of students collaborating on projects.

Most users of e-mail who send messages to multiple recipients enter each recipients e-mail address into the TO: field individually …

Image Reconstruction Using Data-Dependent Triangulation, Thomas W. Sederberg, Xiaohua Yu, Bryan S. Morse

Faculty Publications

Image reconstruction based on data-dependent triangulation with new cost functions and optimization can create higher quality images than traditional bilinear or bicubic spline reconstruction. The article presents a novel method for image reconstruction using a piecewise linear intensity surface whose elements don't generally align with the coordinate axes. This method is based on the technique of data-dependent triangulation (DDT) that N. Dyn et al. (1990) introduced and has proven capable of producing more pleasing reconstructions than axis-aligned methods.

Interpolating Implicit Surfaces From Scattered Surface Data Using Compactly Supported Radial Basis Functions, Bryan S. Morse, David T. Chen, Penny Rheingans, Kalpathi Subramanian, Terry S. Yoo

Faculty Publications

We describe algebraic methods for creating implicit surfaces using linear combinations of radial basis interpolants to form complex models from scattered surface points. Shapes with arbitrary topology are easily represented without the usual interpolation or aliasing errors arising from discrete sampling. These methods were first applied to implicit surfaces by Savchenko, et al. and later developed independently by Turk and O'Brien as a means of performing shape interpolation. Earlier approaches were limited as a modeling mechanism because of the order of the computational complexity involved. We explore and extend these implicit interpolating methods to make them suitable for systems of …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 7, April 2001, 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.

Mage: A Distributed Programming Model, Earl Barr, Raju Pandey, Michael Haungs

Computer Science and Software Engineering

Writing distributed programs is difficult. To ease this task, we introduce a new programming abstraction. which we call a mobility attribute. Mobility attributes provide a syntax that describes the mobility semantics of program components. Programmers attach mobility attributes to program components to dynamically control the placement of these components within the network. Mobility attributes intercept component invocations and decide whether and where to move a component before the component executes. This allows the programmer to improve her program's run-time efficiency by colocating components and resources. We present MAGE, an object oriented distributed system, that supports mobility attributes and illustrates their …

A Software Reliability Model Combining Representative And Directed Testing, Brian Michael Mitchell

Computer Science Theses & Dissertations

Traditionally, software reliability models have required that failure data be gathered using only representative testing methods. Over time, however, representative testing becomes inherently less effective as a means of improving the actual quality of the software under test. Additionally, the use of failure data based on observations made during representative testing has been criticized because of the statistical noise inherent in this type of data. In this dissertation, a testing method is proposed to make reliability testing more efficient and accurate. Representative testing is used early, when the rate of fault revelation is high. Directed testing is used later in …

Computational Geometry Column 41, Joseph O'Rourke

Computer Science: Faculty Publications

The recent result that n congruent balls in R^d have at most 4 distinct geometric permutations is described.

Predictive Self-Organizing Networks For Text Categorization, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

This paper introduces a class of predictive self-organizing neural networks known as Adaptive Resonance Associative Map (ARAM) for classification of free-text documents. Whereas most sta- tistical approaches to text categorization derive classification knowledge based on training examples alone, ARAM performs supervised learn- ing and integrates user-defined classification knowledge in the form of IF-THEN rules. Through our experiments on the Reuters-21578 news database, we showed that ARAM performed reasonably well in mining categorization knowledge from sparse and high dimensional document feature space. In addition, ARAM predictive accuracy and learning efficiency can be improved by incorporating a set of rules derived from …

Effective Use Of The Level-Two Cache For Two Cache For Skewed Tiling (Extended Version), Yonghong Song, Zhiyuan Li

Department of Computer Science Technical Reports

No abstract provided.

Restoration And Reconstruction From Overlapping Images For Multi-Image Fusion, Stephen E. Reichenbach, Jing Li

School of Computing: Faculty Publications

This paper describes a technique for restoring and reconstructing a scene from overlapping images. In situations where there are multiple, overlapping images of the same scene, it may be desirable to create a single image that most closely approximates the scene, based on the data in all of the available images. For example, successive swaths acquired by NASA’s moderate imaging spectrometer (MODIS) will overlap, particularly at wide scan angles, creating a severe visual artifact in the output image. Resampling the overlapping swaths to produce a more accurate image on a uniform grid requires restoration and reconstruction. The one-pass restoration and …

Understanding And Measuring The Sources Of Variation In The Prioritization Of Regression Test Suites, Sebastian Elbaum, David Gable, Gregg Rothermel

School of Computing: Conference and Workshop Papers

Test case prioritization techniques let testers order their test cases so that those with higher priority, according to some criterion, are executed earlier than those with lower priority. In previous work, we examined a variety of prioritization techniques to determine their ability to improve the rate of fault detection of test suites. Our studies showed that the rate of fault detection of test suites could be significantly improved by using more powerful prioritization techniques. In addition, they indicated that rate of fault detection was closely associated with the target program. We also observed a large quantity of unexplained variance, indicating …

Tcp Hack: Tcp Header Checksum Option To Improve Performance Over Lossy Links, Rajesh Krishna Balan, Boon Peng Lee, Renjish Kumar, Jacob Lillykutty, Winston Seah, A. L. Ananda

Research Collection School Of Computing and Information Systems

Wireless networks have become increasingly common and an increasing number of devices are communicating with each other over lossy links. Unfortunately, TCP performs poorly over lossy links as it is unable to differentiate the loss due to packet corruption from that due to congestion. We present an extension to TCP which enables TCP to distinguish packet corruption from congestion in lossy environments resulting in improved performance. We refer to this extension as the HeAder ChecKsum option (HACK). We implemented our algorithm in the Linux kernel and performed various tests to determine its effectiveness. Our results have shown that HACK performs …

Topic Detection, Tracking, And Trend Analysis Using Self-Organizing Neural Networks, Kanagasabai Rajaraman, Ah-Hwee Tan

Research Collection School Of Computing and Information Systems

We address the problem of Topic Detection and Tracking (TDT) and subsequently detecting trends from a stream of text documents. Formulating TDT as a clustering problem in a class of self-organizing neural networks, we propose an incremental clustering algorithm. On this setup we show how trends can be identified. Through experimental studies, we observe that our method enables discovering interesting trends that are deducible only from reading all relevant documents.

Hidden Markov Models For Visual Speech Synthesis In Limited Data, Harold A. Arb

Theses and Dissertations

This work presents a new approach for estimating control points (facial locations that control movement) to allow the artificial generation of video with apparent mouth movement (visual speech) time-synced with recorded audio. First, Hidden Markov Models (HMMs) are estimated for each visual speech category (viseme) present in stored video data, where a category is defined as the mouth movement corresponding to a given sound and where the visemes are further categorized as trisemes (a viseme in the context of previous and following visemes). Next, a decision tree is used to cluster and relate states in the HMMs that are similar …

Little Languages And Their Programming Environments, John Clements, Paul Graunke, Shriram Krishnamurthi, Matthias Felleisen

Computer Science and Software Engineering

Programmers constantly design, implement, and program in little languages. Two different approaches to the implementation of little languages have evolved. One emphasizes the design of little languages from scratch, using conventional technology to implement interpreters and compilers. The other advances the idea of extending a general-purpose host language; that is, the little language shares the host language's features (variables, data, loops, functions) where possible; its interpreters and compilers; and even its type soundness theorem. The second approach is often called a language embedding.

This paper directs the attention of little language designers to a badly neglected area: the programming environments …

Icdm: An Architecture And Toolkit In Support Of Agent-Based, Decision-Support Applications, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Agent-based, decision-support systems provide human decision-makers with a means of solving complex problems through collaboration with heterogeneous collections of both human and computer-based expert agents. Over the past decade the Collaborative Agent Design (CAD) Research Center has developed several proof-of-concept and production-oriented agent-based, decision-support systems for both commercial and Department of Defense applications. These applications range in domain from engineering design to tactical command and control. While diverse in application, each of these systems is predicated on the same set of fundamental principles derived from years of experience in this area. Primary among these principles are the notions of high-level …

Probabilistic Temporal Databases, I: Algebra, Alex Dekhtyar, Robert Ross, V. S. Subrahmanian

Computer Science and Software Engineering

Dyreson and Snodgrass have drawn attention to the fact that in many temporal database applications, there is often uncertainty present about the start time of events, the end time of events, the duration of events, etc. When the granularity of time is small (e.g. milliseconds), a statement such as "Packet p was shipped sometime during the first 5 days of January, 1998" leads to a massive amount of uncertainty (5 X 24 X 60 X 60 X 1000) possibilities. As noted in [41], past attempts to deal with uncertainty in databases have been restricted to relatively small amounts of uncertainty …

Survivability Architecture For Workflow Management Systems, Jorge Cardoso, Zongwei Luo, John A. Miller, Amit P. Sheth, Krzysztof J. Kochut

Kno.e.sis Publications

The survivability of critical infrastructure systems has been gaining increasing concern from the industry. The survivability research area addresses the issue of infrastructure systems that continues to provide pre-established service levels to users in the face of disorders and react to changes in the surrounding environment. Workflow management systems need to be survivable since they are used to support critical and sensitive business processes. They require a high level of dependability and should not allow process instances to be interrupted or aborted due to failures. Moreover, due to their sensitivity, business process should reflect any change in the environment. In …

Modeling The Transient Rate Behavior Of Bandwidth Sharing As A Hybrid Control System, Kang Li, Molly H. Shor, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

This paper uses hybrid control to model a problem of computer network systems, the dynamic behavior of bandwidth sharing among competing TCP traffic. It has been well known in the computer network community that well-behaved (TCP-friendly) congestion control mechanisms are crucial to the robustness of the Internet. Congestion control determines the transmission rate for each flow. Right now, most TCP-friendly research focuses only on the average throughput behavior without considering how the data is sent out in the short-term (e.g. bursty or smooth). However, recent experimental results show that short-term rate adjustments can change the bandwidth sharing result. Therefore, it …