Computer Engineering Commons^™

Security Information Management With Frame-Based Attack Presentation And First-Order Reasoning, Wei Yan

Dissertations

Internet has grown by several orders of magnitude in recent years, and this growth has escalated the importance of computer security. Intrusion Detection System (IDS) is used to protect computer networks. However, the overwhelming flow of log data generated by IDS hamper security administrators from uncovering new insights and hidden attack scenarios. Security Information Management (SIM) is a new growing area of interest for intrusion detection. The research work in this dissertation explores the semantics of attack behaviors and designs Frame-based Attack Representation and First-order logic Automatic Reasoning (FAR-FAR) using linguistics and First-order Logic (FOL) based approaches. Techniques based on …

A Versatile Programming Model For Dynamic Task Scheduling On Cluster Computers, Dejiang Jin

Dissertations

This dissertation studies the development of application programs for parallel and distributed computer systems, especially PC clusters. A methodology is proposed to increase the efficiency of code development, the productivity of programmers and enhance performance of executing the developed programs on PC clusters while facilitating improvement of scalability and code portability of these programs. A new programming model, named the Super-Programming Model (SPM), is created. Programs are developed assuming an instruction set architecture comprised of SuperInstructions (SIs). SPM models the target system as a large Virtual Machine (VM); VM contains functional units which are underlain with sub-computer systems and SIs …

Tcp Performance Enhancement In Wireless Networks Via Adaptive Congestion Control And Active Queue Management, Kai Xu

Dissertations

The transmission control protocol (TCP) exhibits poor performance when used in error-prone wireless networks. Remedy to this problem has been an active research area. However, a widely accepted and adopted solution is yet to emerge. Difficulties of an acceptable solution lie in the areas of compatibility, scalability, computational complexity and the involvement of intermediate routers and switches.

This dissertation rexriews the current start-of-the-art solutions to TCP performance enhancement, and pursues an end-to-end solution framework to the problem. The most noticeable cause of the performance degradation of TCP in wireless networks is the higher packet loss rate as compared to that …

Planar Visual Fusion Scintigraphy, Jacob Puthiamadathil

Theses

Planar scintigraphy, while providing useful information about the distribution of the radiopharmaceutical being used, often does not provide adequate information about the surrounding anatomical structures. A proposed method to solve this problem is by registering and fusing a scintigraphic image with a digital visual image. Fusing planar scintigraphic images with visual photographic images to supply an anatomic correlate to regions of radiopharmaceutical accumulation has been explored in this study. The digital visual image will provide a context for the relevant structures in the scintigraphic image. The validity of using one set of affine transformation parameters for registering all patient data …

Cluster-Based Wireless Mobile Ad-Hoc Network Security, Mandur Bajra Bajracharya

Theses

A wireless ad-hoc network is a cooperative communication network deployed with a specific purpose. It is characterized by dynamically changing topology with no fixed infrastructure which exhibits a perfectly vulnerable state for a number of different kinds of attacks.

This thesis proposes a novel technique of achieving security in wireless mobile ad hoc networks by integrating a simple clustering and a voting mechanism together. The purpose of forming a cluster is to facilitate security in the network and the voting is performed to support the decision making process in the cluster. A procedure of forming small homogenous clusters throughout the …

Enabling Cost Aware Routing With Auctions In Wireless Ad-Hoc Networks, Ali Yuksel

Theses

Battery power is a precious resource in wireless ad-hoc networks, and most routing protocols that have been proposed so far do not generate cost efficient routes. In this thesis, a novel auction-based cost-aware routing scheme, called CARA, is presented. CARA is designed as an extension of the MAC layer, and is shown to improve the cost efficiency of existing ad-hoc routing protocols through dynamic power control, while introducing only minimal additional overhead. The MAC layer at each node is given the capability to run local sealed-bid second-price auctions for the user data packets that need to be transmitted, and to …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 8, May 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.

New Algorithms For Statistical Analysis Of Interval Data, Gang Xiang, Scott A. Starks, Vladik Kreinovich, Luc Longpre

Departmental Technical Reports (CS)

It is known that in general, statistical analysis of interval data is an NP-hard problem: even computing the variance of interval data is, in general, NP-hard. Until now, only one case was known for which a feasible algorithm can compute the variance of interval data: the case when all the measurements are accurate enough -- so that even after the measurement, we can distinguish between different measured values Xi. In this paper, we describe several new cases in which feasible algorithms are possible -- e.g., the case when all the measurements are done by using the same (not necessarily very …

Hide It Or Unbundle It: A Comparison Of The Antitrust Investigations Against Microsoft In The U.S. And The E.U., Sue Ann Mota

The University of New Hampshire Law Review

[Excerpt] "Microsoft Corporation, the world’s largest software company, has been facing antitrust scrutiny globally. In the U.S., after what’s been called the antitrust trial of the century, a consent decree was reached between Microsoft, the United States government, and several states, that closely resembled the litigated remedy that the remaining states received. Only Massachusetts appealed the litigated remedy, which was approved by the appeals court on June 30, 2004. In the United States, Microsoft was required to hide, but not remove, the Internet Explorer browser on the Windows Operating System. While antitrust litigation was ongoing in the United States against …

Architectures For Rule Processing Intrusion Detection And Prevention Systems, Michael E. Attig

All Computer Science and Engineering Research

High-performance intrusion detection and prevention systems are needed by network administrators in order to protect Internet systems from attack. Researchers have been working to implement components of intrusion detection and prevention systems for the highly popular Snort system in reconfigurable hardware. While considerable progress has been made in the areas of string matching and header processing, complete systems have not yet been demonstrated that effectively combine all of the functionality necessary to perform intrusion detection and prevention for real network systems. In this thesis, three architectures to perform rule processing, the heart of intrusion detection and prevention, are presented. The …

Using A Pda To Control Home Appliances, Atif Albraiki

Renée Crown University Honors Thesis Projects - All

The Personal Digital Assistant (PDA) is a handheld device that gives users different organizational capabilities. Over the years, the functionality of PDAs has expanded tremendously to include internet connectivity and different computer applications. The purpose of my honors thesis, combined with my engineering senior design project, was to include a new functionality to the PDA and use it to control different home appliances. The goal of the project was to develop a PDA program that will communicate with a PC program, and have the PC program communicate with a microcontroller to control home appliances. My part of the project was …

Synthesizing E-Government Stage Models – A Meta-Synthesis Based On Meta-Ethnography Approach, Keng Siau, Y. Long

Research Collection School Of Computing and Information Systems

The growing interest in e-government raises the question of stages in e-government development. A few stage models for e-government have been proposed. Without a common e-government stage model, different research in e-government may be based on different stage models. This presents a difficulty in comparing and understanding different research results. In this research, we synthesize the existing e-government stage models so that there is a common frame of reference for researchers and practitioners in the area.

Improving The Performance Of Internet Data Transport, Anshul Kantawala, Jonathan S. Turner

All Computer Science and Engineering Research

With the explosion of the World Wide Web, the Internet infrastructure faces new challenges in providing high performance for data traffic. First, it must be able to pro-vide a fair-share of congested link bandwidth to every flow. Second, since web traffic is inherently interactive, it must minimize the delay for data transfer. Recent studies have shown that queue management algorithms such as Tail Drop, RED and Blue are deficient in providing high throughput, low delay paths for a data flow. Two major shortcomings of the current algorithms are: they allow TCP flows to get synchronized and thus require large buffers …

Synthesizing E-Government Stage Models – A Meta-Synthesis Based On Meta-Ethnography Approach, Keng Siau, Y. Long

Research Collection School Of Computing and Information Systems

The growing interest in e-government raises the question of stages in e-government development. A few stage models for e-government have been proposed. Without a common e-government stage model, different research in e-government may be based on different stage models. This presents a difficulty in comparing and understanding different research results. In this research, we synthesize the existing e-government stage models so that there is a common frame of reference for researchers and practitioners in the area.

Optimal Flux Weakening In Surface Pm Machines Using Fractional-Slot Concentrated Windings, Ayman M. El-Refaie, Thomas M. Jahns

Electrical and Computer Engineering Faculty Research and Publications

A design approach is presented for achieving optimal flux-weakening operation in surface permanent-magnet (SPM) synchronous machines by properly designing the machine's stator windings using concentrated, fractional-slot stator windings. This technique makes it possible to significantly increase the machine inductance in order to achieve the critical condition for providing wide speed ranges of constant-power operation. The conditions for optimal flux weakening can be achieved while simultaneously delivering sinusoidal line-to-line back-electromotive-force waveforms and low cogging torque. A closed-form analytical model is described that can be used to design SPM machines to achieve optimal flux-weakening conditions. This technique is applied to design a …

Capacity And Complexity Of Hmm Duration Modeling Techniques, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

The ability of a standard hidden Markov model (HMM) or expanded state HMM (ESHMM) to accurately model duration distributions of phonemes is compared with specific duration-focused approaches such as semi-Markov models or variable transition probabilities. It is demonstrated that either a three-state ESHMM or a standard HMM with an increased number of states is capable of closely matching both Gamma distributions and duration distributions of phonemes from the TIMIT corpus, as measured by Bhattacharyya distance to the true distributions. Standard HMMs are easily implemented with off-the-shelf tools, whereas duration models require substantial algorithmic development and have higher computational costs when …

Effects Of Load Magnitude On Diagnosing Broken Bar Faults In Induction Motors Using The Pendulous Oscillation Of The Rotor Magnetic Field Orientation, Behrooz Mirafzal, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

The effects of load level on the ability to diagnose broken bar faults in squirrel-cage induction motors are studied in this paper. The pendulous oscillation of the rotor magnetic field orientation is implemented as a fault signature for rotor fault diagnostic purposes at steady-state operations. Moreover, the effects of load level on the low-side band component of the stator current spectrum, and associated diagnostic difficulties in this approach particularly in the presence of motor operation from pulsewidth-modulation drives, are reported as well. These investigations were performed through testing 2-hp and 5-hp induction motors over a wide range of load levels …

Nanoindentation Technique For Characterizing Cantilever Beam Style Rf Microelectromechanical Systems (Mems) Switches, Hyukjae Lee, Ronald A. Coutu Jr., Shankar Mall, Paul E. Kladitis

Electrical and Computer Engineering Faculty Research and Publications

A nanoindentation technique was used to mechanically actuate a radio frequency micro-switch along with the measurement of contact resistance to investigate its applicability to characterize deflection and contact resistance behaviors of micro-sized cantilever beam switches. The resulting load–displacement relationship showed a discontinuity in slope when the micro-switch closed. The measured spring constants reasonably agreed with theoretical values obtained from the simple beam models. The change in contact resistance during test clearly indicated micro-switch closure but it did not coincide exactly with the physical contact between two electric contacts due to a resistive contaminated film.

Static Determination Of Allocation Rates To Support Real-Time Garbage Collection, Tobias Mann

All Computer Science and Engineering Research

While it is generally accepted that garbage-collected languages offer advantages over languages in which objects must be explicitly deallocated, real-time developers are leery of the adverse effects a garbage collector might have on real-time performance. Semiautomatic approaches based on regions have been proposed, but incorrect usage could cause unbounded storage leaks or program failure. Moreover, correct usage cannot be guaranteed at compile-time. Recently, real-time garbage collectors have been developed that provide a guaranteed fraction of the CPU to the application, and the correct operation of those collectors has been proven, subject only to the specification of certain statistics related to …

Composable Timed Automata Models For Real-Time Embedded Systems Middleware, Venkita Subramonian, Christopher Gill, Cesar Sanchez, Henny Sipma

All Computer Science and Engineering Research

Middleware for distributed real-time embedded (DRE) systems has grown more and more complex in recent years, to address functional and temporal requirements of complex real-time applications. While current approaches for modeling middleware have eased the task of assembling, deploying and configuring middleware and applications, a more formal, fundamental and lower-level set of models is needed to be able to uncover subtle safety and timing errors introduced by interference between computations, particularly in the face of alternative concurrency strategies in the middleware layer. In this paper, we examine how formal models of lower-level middleware building blocks provide an appropriate level of …

What A Mesh: Dependent Data Types For Correct Mesh Manipulation Algorithms, Joel R. Brandt

All Computer Science and Engineering Research

The Edinburgh Logical Framework (LF) has been proposed as a system for expressing inductively defined sets. I will present an inductive definition of the set of manifold meshes in LF. This definition takes into account the topological characteri-zation of meshes, namely their Euler Characteristic. I will then present a set of dependent data types based on this inductive def-inition. These data types are defined in a programming language based on LF. The language’s type checking guarantees that any typeable expression represents a correct manifold mesh. Furthermore, any mesh can be represented using these data types. Hence, the encoding is sound …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 7, April 2005, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Use Of Maxitive (Possibility) Measures In Foundations Of Physics And Description Of Randomness: Case Study, A. M. Finkelstein, Olga Kosheleva, Vladik Kreinovich, Scott A. Starks, Hung T. Nguyen

Departmental Technical Reports (CS)

According to the traditional probability theory, events with a positive but very small probability can occur (although very rarely). For example, from the purely mathematical viewpoint, it is possible that the thermal motion of all the molecules in a coffee cup goes in the same direction, so this cup will start lifting up.

In contrast, physicists believe that events with extremely small probability cannot occur. In this paper, we show that to get a consistent formalization of this belief, we need, in addition to the original probability measure, to also consider a maxitive (possibility) measure.

From Fuzzification And Intervalization To Anglification: A New 5d Geometric Formalism For Physics And Data Processing, Scott A. Starks, Vladik Kreinovich

Departmental Technical Reports (CS)

We show that in understanding foundations of modern physics, with its 10-dimensional (and higher-dimensional) space-time models, it is very helpful to use the main ideas behind fuzzification -- extension of arithmetic operations and elementary functions from exact numbers to fuzzy numbers. The resulting formalism is, from the mathematical viewpoint, somewhat more complex than the traditional fuzzy arithmetic, but it is still much simpler than the quantum field theory -- and thus, it helps to make several important ideas from foundations of modern physics much more intuitively clear.

The Interval Categorizer Tesselation-Based Model For High Perfomance Computing, Marilton S. De Aguiar, Gracaliz P. Dimuro, Antonio C. Da Rocha Costa, Rafael K.S. Silva

Departmental Technical Reports (CS)

The paper presents the results obtained by an implementation of the interval tessellation-based model for categorization of geographic regions according the analysis of the relief function declivity, called ICTM. The analysis of the relief declivity, which is embedded in the rules of the model ICTM, categorizes each tessellation cell, with respect to the whole considered region, according to the (positive, negative, null) signal of the declivity of the cell. Such information is represented in the states assumed by the cells of the model. The overall configuration of such cells allows the division of the region into sub-regions of cells belonging …

Random Interval Arithmetic Is Closer To Common Sense: An Observation, Rene Alt, Jean-Luc Lamotte, Vladik Kreinovich

Departmental Technical Reports (CS)

From the commonsense viewpoint, if on a bridge whose weight we know with an accuracy of 1 ton, we place a car whose weight we know with an accuracy of 5 kg, then the accuracy with which we know the overall weight of a bridge with a car on it should still be 1 ton. This is what an engineer or a physicist would say. Alas, this is not so in traditional interval arithmetic. In this paper, we show that, in contrast to traditional interval arithmetic, the random interval arithmetic (proposed by the first two authors) actually has this important …

How The Concept Of Information As Average Number Of "Yes"-"No" Questions (Bits) Can Be Extended To Intervals, P-Boxes, And More General Uncertainty, Vladik Kreinovich, Gang Xiang, Scott Ferson

Departmental Technical Reports (CS)

We explain how the concept of information as average number of "yes"-"no" questions (bits) can be extended to intervals, p-boxes, and more general uncertainty.

Interval Methods: An Introduction, Luke Achenie, Vladik Kreinovich, Kaj Madsen

Departmental Technical Reports (CS)

The ongoing development of ever more advanced computers provides the potential for solving increasingly difficult computational problems. However, given the complexity of modern computer architectures, the task of realizing this potential needs careful attention. A main concern of High Performance Computing is the development of software that optimizes the performance of a given computer.

An important characteristic of the computer performance in scientific computing is the accuracy of the computation results. Often, we can estimate this accuracy by using traditional statistical techniques. However, in many practical situations, we do not know the probability distributions of different measurement, estimation, and/or roundoff …

Supporting Documentation For The Sps-Prospec Case Study, Salamah I. Salamah, Ann Q. Gates

Departmental Technical Reports (CS)

In this work, we report on the results of a case study comparing the correctness of Linear Temporal Logic (LTL)formulas generated by the Property Specification Tool Prospec and the Specification Pattern System (SPS). The report includes all the components used in the case study. In addition, this report provides a description of the use of the SPIN model checker to verify correctness of LTL specifications. Particularly, the report provides screenshots of XSPIN (SPIN�s graphical interface) and how properties (i.e., LTL formulas) can be specified and verified.

How To Reconstruct The Original Shape Of A Radar Signal?, Matthew G. Averill, Gang Xiang, Vladik Kreinovich, George R. Keller, Scott A. Starks, Patrick S. Debroux, James Boehm

Departmental Technical Reports (CS)

The shape of the radar signal can provide us with the additional information about the reflecting surface. However, to decrease the noise, radars use filtering, and filtering changes the shapes of the radar signal. It is therefore necessary to reconstruct the original shape of the radar signal.