Physical Sciences and Mathematics Commons^™

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 8, May 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.

Simulation Of Inviscid Multi-Species Plasma Flow, Alexandre Martin, Marcelo Reggio, Jean-Yves Trépanier

Alexandre Martin

A multi-species solver for plasma at thermodynamical equilibrium is developed. A numerical scheme, based on Roe's, is implemented with some modification regarding the average quantities. A perfect gas treatment is carried out for validations, and a quasi-real gas treatment is also presented. The latter takes into account the changes in the composition of the gas caused by fluctuations in temperature and density.

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

Department of Computer Science Technical Reports

No abstract provided.

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.

Making Use Of The Most Expressive Jumping Emerging Patterns For Classification, Jinyan Li, Guozhu Dong, Kotagiri Ramamohanarao

Kno.e.sis Publications

Classification aims to discover a model from training data that can be used to predict the class of test instances. In this paper, we propose the use of jumping emerging patterns (JEPs) as the basis for a new classifier called the JEP-Classifier. Each JEP can capture some crucial difference between a pair of datasets. Then, aggregating all JEPs of large supports can produce a more potent classification power. Procedurally, the JEP-Classifier learns the pair-wise features (sets of JEPs) contained in the training data, and uses the collective impacts contributed by the most expressive pair-wise features to determine the class labels …

Strategies For Handling Spatial Uncertainty Due To Discretization, Thomas Windholz

Electronic Theses and Dissertations

Geographic information systems (GISs) allow users to analyze geographic phenomena within areas of interest that lead to an understanding of their relationships and thus provide a helpful tool in decision-making. Neglecting the inherent uncertainties in spatial representations may result in undesired misinterpretations. There are several sources of uncertainty contributing to the quality of spatial data within a GIS: imperfections (e.g., inaccuracy and imprecision) and effects of discretization. An example for discretization in the thematic domain is the chosen number of classes to represent a spatial phenomenon (e.g., air temperature). In order to improve the utility of a GIS an inclusion …

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.

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 …

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 …

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 …

Access To Geographic Scientific And Technical Data In An Academic Setting, Bastiaan Van Loenen

Electronic Theses and Dissertations

Data availability is a key issue affecting society's social well being. Information technology has increased the availability of and improved access to data. The academic community that uses spatial data is one of the groups that has taken advantage of fast and inexpensive opportunities to share data and knowledge in a relatively unfettered fashion across digital networks. However, pressure by the private sector to increase protection for databases through database legislation, self-help measures (contracts, licensing and technological methods for limiting access) and movement by some local governments towards revenue generation from sales of data are decreasing or threatening to decrease …

Cluster Computing In The Classroom: Topics, Guidelines, And Experiences, Amy Apon, Rajkumar Buyya, Hai Jin, Jens Mache

Publications

With the progress of research on cluster computing, more and more universities have begun to offer various courses covering cluster computing. A wide variety of content can be taught in these courses. Because of this, a difficulty that arises is the selection of appropriate course material. The selection is complicated by the fact that some content in cluster computing is also covered by other courses such as operating systems, networking, or computer architecture. In addition, the background of students enrolled in cluster computing courses varies. These aspects of cluster computing make the development of good course material difficult. Combining our …

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 …

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 …

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 …

Ontology-Driven Geographic Information Systems, Frederico Torres Fonseca

Electronic Theses and Dissertations

Information integration is the combination of different types of information in a framework so that it can be queried, retrieved, and manipulated. Integration of geographic data has gained in importance because of the new possibilities arising from the interconnected world and the increasing availability of geographic information. Many times the need for information is so pressing that it does not matter if some details are lost, as long as integration is achieved. To integrate information across computerized information systems it is necessary first to have explicit formalizations of the mental concepts that people have about the real world. Furthermore, these …

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.

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 …

Management, Retrieval, And Visualization Of Spatial Data From Airborne Light Detection And Ranging System (Lidar) Survey, Zheng Cui

FIU Electronic Theses and Dissertations

The primary purpose of this research was to develop new methodologies to process and analyze large amount of topographic data from airborne LIDAR (light detection and ranging) survey.

This research developed a suite of algorithms to resample dense clouds of point data from LIDAR survey, cut the large data set into smaller tiles, and filtered data to remove points from non-ground surface features such as vegetations, buildings, and vehicles. These algorithms were implemented on the PC platform using C++. The test results showed that the developed application software package based on these algorithms worked well. This application software package provided …

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 …

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.

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.

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

CSE 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 …

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 …

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.

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.

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 …

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 …