Digital Commons Network^™

Learning Nonstationary Models Of Normal Network Traffic For Detecting Novel Attacks, Philip K. Chan, Matthew V. Mahoney

Electrical Engineering and Computer Science Faculty Publications

Traditional intrusion detection systems (IDS) detect attacks by comparing current behavior to signatures of known attacks. One main drawback is the inability of detecting new attacks which do not have known signatures. In this paper we propose a learning algorithm that constructs models of normal behavior from attack-free network traffic. Behavior that deviates from the learned normal model signals possible novel attacks. Our IDS is unique in two respects. First, it is nonstationary, modeling probabilities based on the time since the last event rather than on average rate. This prevents alarm floods. Second, the IDS learns protocol vocabularies (at the …

Implementation Of Viterbi Decoder On Xilinx Xc4005xl Fpga, Nabil Abu-Khader

Wayne State University Theses

The Viterbi decoding algorithm is used to decode convolutional codes and is found in many systems that receive digital data that might contain errors. The use of error-correcting codes has proven tobe an effective way to overcome data corruption in digital communication channels. In previous works, researchers describe the Viterbi Algorithm, but the accuracy does not exceed 10% of data points. Also, a lot of previous works do not follow IEEE 802.16 new specifications. Viterbi decoders are generally implemented using programmable digital signal processors (DSPs) or special purpose chip sets and application-specific integrated circuits (ASICs). Here, we aim to implement …

Establishing A Lan Network For Designing And Analyzing Of Manufacturing Products, Yuqiu You

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Yuqiu You in Spring of 2002.

From Linear To Nonlinear Control Means: A Practical Progression, Zhiqiang Gao

Electrical and Computer Engineering Faculty Publications

With the rapid advance of digital control hardware, it is time to take the simple but effective proportional-integral-derivative (PID) control technology to the next level of performance and robustness. For this purpose, a nonlinear PID and active disturbance rejection framework are introduced in this paper. It complements the existing theory in that (1) it actively and systematically explores the use of nonlinear control mechanisms for better performance, even for linear plants; (2) it represents a control strategy that is rather independent of mathematical models of the plants, thus achieving inherent robustness and reducing design complexity. Stability analysis, as well as …

Robust Face Representation And Recognition Under Low Resolution And Difficult Lighting Conditions, Mohammad Moinul Islam

Electrical & Computer Engineering Theses & Dissertations

This dissertation focuses on different aspects of face image analysis for accurate face recognition under low resolution and poor lighting conditions. A novel resolution enhancement technique is proposed for enhancing a low resolution face image into a high resolution image for better visualization and improved feature extraction, especially in a video surveillance environment. This method performs kernel regression and component feature learning in local neighborhood of the face images. It uses directional Fourier phase feature component to adaptively lean the regression kernel based on local covariance to estimate the high resolution image. For each patch in the neighborhood, four directional …

Develops The Software Of Dsp Processor For The Cdma Circuitry, Arman Djohan D.

Makara Journal of Technology

This research develops the software of DSP Processor type TMS320C54X for the CDMA circuitry. This research apply two algorithms namely Mathematic Algorithm and table lookup Algorithm. From both algorithms, the research examine what algorithm have the fasted processing time and the smallest memory occupation. From the examination results the Mathematic Algorithm have 20.62 milliseconds processing time and the Table lookup algorithm have 14.08 milliseconds processing time. The Table lookup algorithm have the fastest processing time because the Matematic algorithm need the rounding process of the fi gure. Eventhough such processing time is not exceed from the 125 millisecond of delay …

Improvements In Wavelength Modulation Spectroscopy Using Ratios Of Higher Harmonics, James Michael Barrington

Electrical & Computer Engineering Theses & Dissertations

Experiments in Wavelength Modulation Spectroscopy have been conducted at Old Dominion University since 1996. The method provides a highly sensitive, nonintrusive method of probing gases. Research has concentrated on effectively modeling the higher harmonic shapes that are measured experimentally. Accurately modeling these signals will result in the ability to reliably extract the information contained in transition line shapes.

In order to accurately depict the signals, the theory must be thoroughly understood. This thesis develops the theory of Wavelength Modulation Spectroscopy from two aspects: a direct Fourier series expansion of a time varying intensity profile and through communication theory. In addition, …

A Study Of Radiofrequency Effects On Gene Expression, Elizabeth A. Coln

Electrical & Computer Engineering Theses & Dissertations

Numerous studies have been completed over the past several years to look at the non-thermal effects of low-level radiofrequency exposure on biological systems. These studies were done to determine if exposure to radiofrequency fields are safe, or if they may lead to health problems or changes to any of the biological processes continually occurring within the human body. Responses measured include stress responses (I), gene expression (2), cell proliferation (3), cell morphology (4), and changes in DNA (5).

Dispersion is the most common model for explaining the electric behavior of biomaterials. It refers to the corresponding frequency domain concept of …

Embedded Software Programming To Develop A Command Line User Interface For Monitoring And Debugging A Manually Driven Gas Regulator Control System, Syed N. Hyder

Electrical & Computer Engineering Theses & Dissertations

This thesis presents a complete embedded programming model and software codes for a command-line user interface for CONCOA's gas regulator control system. Control Corporation of America (CONCOA) manufactures high-pressure gas regulators, which mechanically control the pressure at their outlets. Since the control system is based on mechanical regulators, adding or stopping gas flow from the system can cause manifold fluctuation that could further cause the pressure to rise or fall with time. The main motivation for developing a command line user interface is to provide a centralized computer control to monitor and debug the gas regulator control system electronically by …

A Formal Object Model For Layered Networks To Support Verification And Simulation, Rasha M. B. E. Morsi

Electrical & Computer Engineering Theses & Dissertations

This work presents an abstract formal model of the interconnection structure of the Open Systems Interconnection Reference Model (OSI-RM) developed using Object-Oriented modeling principles permitting it to serve as a re-usable platform in supporting the development of simulations and formal methods applied to layered network protocols. A simulation of the object model using MODSIM III was developed and Prototype Verification System (PVS) was used to show the applicability of the object model to formal methods by formally specifying and verifying a Global Systems for Mobile communications (GSM) protocol. This application has proved to be successful in two aspects. The first …

Evaluation And Analysis Of Array Antennas For Passive Coherent Location (Pcl) Systems, Baris Calikoglu

Theses and Dissertations

Passive Coherent Location (PCL) systems use a special form of a radar receiver that exploits the ambient radiation in the environment to detect and track targets. Typical transmissions of opportunity that might be exploited include television and FM radiobroadcasts. PCL implies the use of a non-radar electromagnetic sources of illumination, such as commercial radio or television broadcasts also referred as transmitters of opportunity. The use of such illumination sources means that the receiver needs to process waveforms that are not designed for radar purposes. As a consequence, the receivers for PCL systems must be much more customized than traditional receivers, …

Microdot - A Four-Bit Microcontroller Designed For Distributed Low-End Computing In Satellites, Anthony R. Woodcock

Theses and Dissertations

Many satellites are an integrated collection of sensors and actuators that require dedicated real-time control. For single processor systems, additional sensors require an increase in computing power and speed to provide the multi-tasking capability needed to service each sensor. Faster processors cost more and consume more power, which taxes a satellite's power resources and may lead to shorter satellite lifetimes. An alternative design approach is a distributed network of small and low power microcontrollers designed for space that handle the computing requirements of each individual sensor and actuator. The design of microdot, a four-bit microcontroller for distributed low-end computing, is …

Statistical Error Analysis Of A Doa Estimator For A Pcl System Using The Cramer-Rao Bound Theorem, Kerim Say

Theses and Dissertations

Direction of Arrival (DOA) estimation of signals has been a popular research area in Signal Processing. DOA estimation also has a significant role in the object location process of Passive Coherent Location (PCL) systems. PCL systems have been in open literature since 1986 and their applications are not as clearly understood as the DOA estimation problem. However, they are the focus of many current research efforts and show much promise. The purpose of this research is to analyze the DOA estimation errors in a PCL system. The performance of DOA estimators is studied using the Cramer-Rao Bound (CRB) Theorem. The …

Development And Characterization Of An Emergency Communications System Using Near Vertical Incident Skywave Antennas, Richard A. Allnutt

Theses and Dissertations

The NVIS system characterized in this work was designed to eliminate skip propagation by optimizing the design for contiguous coverage. The NVIS technique involves use of transmission and receiving antennas that create nearly vertical propagation and continuous coverage from the transmitter to a distance of 200 miles. Man portable, very low power transceivers (5 watts maximum) and horizontal dipole antennas five feet above the ground are used in an NVIS communication system for this work. The system is designed for the purpose of supporting communication with emergency workers in areas where other communication is difficult. Digital and analog effectiveness are …

Translation And Rotation Invariant Multiscale Image Registration, Jennifer L. Manfra

Theses and Dissertations

The most recent research involved registering images in the presence of translations and rotations using one iteration of the redundant discrete wavelet transform. We extend this work by creating a new multiscale transform to register two images with translation or rotation differences, independent of scale differences between the images. Our two-dimensional multiscale transform uses an innovative combination of lowpass filtering and the continuous wavelet transform to mimic the two-dimensional redundant discrete wavelet transform. This allows us to obtain multiple subbands at various scales while maintaining the desirable properties of the redundant discrete wavelet transform. Whereas the discrete wavelet transform produces …

Diagnostics Of Bar And End-Ring Connector Breakage Faults In Polyphase Induction Motors Through A Novel Dual Track Of Time-Series Data Mining And Time-Stepping Coupled Fe-State Space Modeling, Richard J. Povinelli, John F. Bangura, Nabeel Demerdash, Ronald H. Brown

Electrical and Computer Engineering Faculty Research and Publications

This paper develops the fundamental foundations of a technique for detection of faults in induction motors that is not based on the traditional Fourier transform frequency domain approach. The technique can extensively and economically characterize and predict faults from the induction machine adjustable speed drive design data. This is done through the development of dual-track proof-of-principle studies of fault simulation and identification. These studies are performed using our proven Time Stepping Coupled Finite Element-State Space method to generate fault case data. Then, the fault cases are classified by their inherent characteristics, so-called “signatures” or “fingerprints.” These fault signatures are extracted …

Design And Fabrication Of Micro-Electro-Mechanical Structures For Tunable Micro-Optical Devices, Michael C. Harvey

Theses and Dissertations

Tunable micro-optical devices are expected to be vital for future military optical communication systems. In this research I seek to optimize the design of a microelectromechanical (MEM) structure integrated with a III-V semiconductor micro-optical device. The resonant frequency of an integrated optical device, consisting of a Fabry-Perot etalon or vertical cavity surface emitting laser (VCSEL), may be tuned by applying an actuation voltage to the MEM Flexure, thereby altering the device's optical cavity length. From my analysis I demonstrate tunable devices compatible with conventional silicon 5V integrated circuit technology. My design for a Fabry-Perot etalon has a theoretical tuning range …

Ambiguity Function Analysis And Direct-Path Signal Filtering Of The Digital Audio Broadcast (Dab) Waveform For Passive Coherent Location (Pcl), Abdulkadir Guner

Theses and Dissertations

This research presents an ambiguity function analysis of the digital audio broadcast (DAB) waveform and one signal detection approach based on signal space projection techniques that effectively filters the direct-path signal from the receiver target channel. Currently, most Passive Coherent Location (PCL) research efforts are focused and based on frequency modulated (FM) radio broadcasts and analog television (TV) waveforms. One active area of PCL research includes the search for new waveforms of opportunity that can be exploited for PCL applications. As considered for this research, one possible waveform of opportunity is the European digital radio standard DAB. For this research, …

An Analysis Of Mutually Dispersive Brown Symbols For Non-Linear Ambiguity Suppression, Matthew J. Papaphotis

Theses and Dissertations

This thesis significantly advances research towards the implementation of optimal Non-linear Ambiguity Suppression (NLS) waveforms by analyzing the Brown theorem. The Brown theorem is reintroduced with the use of simplified linear algebraic notation. A methodology for Brown symbol design and digitization is provided, and the concept of dispersive gain is introduced. Numerical methods are utilized to design, synthesize, and analyze Brown symbol performance. The theoretical performance in compression and dispersion of Brown symbols is demonstrated and is shown to exhibit significant improvement compared to discrete codes. As a result of this research a process is derived for the design of …

Efficient Modeling Of Discontinuities And Dispersive Media In Printed Transmission Lines, R. Araneo, Chen Wang, Xiaoxiong Gu, James L. Drewniak, S. Celozzi

Electrical and Computer Engineering Faculty Research & Creative Works

The finite-difference time-domain method is applied to the analysis of transmission lines on printed circuit boards. The lossy, dispersive behavior of the dielectric substrate is accurately accounted for by means of several algorithms whose accuracy is discussed and compared. Numerical results are validated by comparisons with measurements and an equivalent circuit of slot in the ground plane is proposed.

On The Use Of Linda As A Framework For Distributed Database Systems, Madhan M. Thirukonda, Ronaldo Menezes

Electrical Engineering and Computer Science Faculty Publications

Linda is a coordination language capable of solving issues in distributed computing environments that relate to process synchronization, communication and creation. The expressiveness of Linda in distributed systems is such that researchers are proposing novel applications using Linda as a primary means of coordination. The examples range from peer-to-peer to groupware computing, from simple chat applications to control systems. Surprisingly, Linda has not been used in the field of distributed databases, although Linda can be helpful in solving coordination issues in a distributed database system. In this paper, we look at a possibility of using Linda in the context of …

Modeling, Fabrication, And Optimization Of Niobium Cavities – Phase I: Quarterly Progress Report November 20, 2001 - February 20, 2002, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Multipacting is one of the major loss mechanisms in RF superconductivity cavities for accelerators. This loss mechanism limits the maximum amount of energy/power supported by the cavities. Optimal designs have been identified in others’ studies. In practice, these designs are not easily manufactured. Chemical etching processes used to polish the cavity walls result in a nonuniform surface etch. A nonuniform surface etch will leave some unclean areas with contaminants and micron size particles. These significantly affect multipacting. Further, a nonuniform etch will leave areas with damaged grain structure, which is not good for superconducting properties. Typically, the depth of chemical …

Forces On Permeable Conductors In Magnetic Fields, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

It is often implied that the force density formula dF/dV = JXB is all that is required to calculate the force that would be experienced by any stationary current-carrying medium in a region of space containing a magnetic field. However, representations of this formula are not all compatible, and the methods of applying such formulas when the conductor or surrounding medium have permeabilities different from vacuum are not widely known. The simplest case that one might consider is that of a current-carrying wire in an otherwise uniform field. It appears that the experimental measurements corresponding to such a situation have …

On Performance Analysis And Implementation Issues Of Iterative Decoding For Graph Based Codes, Xuefei Wei

Dissertations

There is no doubt that long random-like code has the potential to achieve good performance because of its excellent distance spectrum. However, these codes remain useless in practical applications due to the lack of decoders rendering good performance at an acceptable complexity. The invention of turbo code marks a milestone progress in channel coding theory in that it achieves near Shannon limit performance by using an elegant iterative decoding algorithm. This great success stimulated intensive research oil long compound codes sharing the same decoding mechanism. Among these long codes are low-density parity-check (LDPC) code and product code, which render brilliant …

On The Data Hiding Theory And Multimedia Content Security Applications, Litao Gang

Dissertations

This dissertation is a comprehensive study of digital steganography for multimedia content protection. With the increasing development of Internet technology, protection and enforcement of multimedia property rights has become a great concern to multimedia authors and distributors. Watermarking technologies provide a possible solution for this problem.

The dissertation first briefly introduces the current watermarking schemes, including their applications in video,, image and audio. Most available embedding schemes are based on direct Spread Sequence (SS) modulation. A small value pseudo random signature sequence is embedded into the host signal and the information is extracted via correlation. The correlation detection problem is …

Renegotiation Based Dynamic Bandwidth Allocation For Selfsimilar Vbr Traffic, Zafer Sahinoglu

Dissertations

The provision of QoS to applications traffic depends heavily on how different traffic types are categorized and classified, and how the prioritization of these applications are managed. Bandwidth is the most scarce network resource. Therefore, there is a need for a method or system that distributes an available bandwidth in a network among different applications in such a way that each class or type of traffic receives their constraint QoS requirements.

In this dissertation, a new renegotiation based dynamic resource allocation method for variable bit rate (VBR) traffic is presented. First, pros and cons of available off-line methods that are …

Qos Routing Source Routing Problems And Solutions, Ye Tian

Theses

The notion of Quality-of-Service has been proposed to capture qualitatively or quantitatively defined performance contracts between the service provider and the user applications. Integrated network services are designed to support Quality-of-Service (QoS). One of the primary goals for the integrated network services is to find the paths that satisfy given QoS requirements, namely QoS routing. The challenging issue in this area is to route packets subjected to multiple uncorrelated constraints because the problem is inherently NP-complete. This thesis studies the source routing heuristic approaches that bring the time complexity down to the polynomial-time for the multi-constrained path (MCP) problem. A …

Hyperbolic Position Location Estimator With Tdoas From Four Stations, Sreeram Potluri

Theses

This thesis presents a detailed derivation of a set of equations needed to locate the three dimensional position of a mobile given the locations of four fixed stations (like a global positioning system (GPS) satellite or a base station in a cell) and the signal time of arrival (TOA) from the mobile to each station. From these derived equations, a synthesizable VHDL model was developed and simulated using IEEE numen*c_std package. All the inputs and outputs were described by 32 bit vectors. From the simulations, it was observed that in the best case the mobile position was off by I …

Energy Band Bowing Parameter In Alxga1-Xn Alloys, Feng Yun, Michael A. Reshchikov, Lei He, Thomas King, Hadis Morkoç, Steve W. Novak, Luncun Wei

Electrical and Computer Engineering Publications

Molecular-beam epitaxy grown AlxGa1−xN alloys covering the entire range of alloy compositions, 0⩽x⩽1, have been used to determine the alloy band gap dependence on its composition. The Alchemical composition was deduced from secondary ion mass spectroscopy and Rutherford backscattering. The composition was also inferred from x-ray diffraction. The band gap of the alloy was extracted from low temperature optical reflectance measurements which are relatively more accurate than photoluminescence. Fitting of the band gap data resulted in a bowing parameter of b=1.0 eV over the entire composition range. The improved accuracy of the composition and band gap determination …

Implementation Of A Si/Sic Hybrid Optically Controlled High-Power Switching Device, Prashant Bhadri, Kuntao Ye, Elena A. Guliants, Fred R. Beyette Jr.

Electrical and Computer Engineering Faculty Publications

The ever-increasing performance and economy of operation requirements placed on commercial and military transport aircraft are resulting in very complex systems. As a result, the use of fiber optic component technology has lead to high data throughput, immunity to EMI, reduced certification and maintenance costs and reduced weight features. In particular, in avionic systems, data integrity and high data rates are necessary for stable flight control. Fly-by-Light systems that use optical signals to actuate the flight control surfaces of an aircraft have been suggested as a solution to the EMI problem in avionic systems. Current fly-by-light systems are limited by …