Digital Commons Network^™

Development Of An Ontology Based Forensic Search Mechanism: Proof Of Concept, Jill Slay, Fiona Schulz

Journal of Digital Forensics, Security and Law

This paper examines the problems faced by Law Enforcement in searching large quantities of electronic evidence. It examines the use of ontologies as the basis for new forensic software filters and provides a proof of concept tool based on an ontological design. It demonstrates that efficient searching is produced through the use of such a design and points to further work that might be carried out to extend this concept.

Radio Frequency Enabled Soil Redox Potential Sensor Networks, Chris Holme

Theses : Honours

There is a need for' cost effective tools and data collection methods for field measurements; to increase both productivity and volumes of collected data in the quest for enhanced understanding and management of environmental systems. To such end, various technologies that may be combined into a cost effective soil redox sensor network were explored. Suitability of each technology, as a component of said network was evaluated. A prototype soil redox sensor network was constructed and basic laboratory and field testing was completed. Results indicate that the prototype sensor network functions correctly within bounds. Both laboratory and field testing show that …

On-Off Frequency-Shift Keying For Wideband Fading Channels, Mustafa Cenk Gursoy, H. Vincent Poor, Sergio Verdu

Department of Electrical and Computer Engineering: Faculty Publications

M-ary on-off frequency-shift keying (OOFSK) is a digital modulation format in which M-ary FSK signaling is overlaid on on/off keying. This paper investigates the potential of this modulation format in the context of wideband fading channels. First, it is assumed that the receiver uses energy detection for the reception of OOFSK signals. Capacity expressions are obtained for the cases in which the receiver has perfect and imperfect fading side information. Power efficiency is investigated when the transmitter is subject to a peak-to-average power ratio (PAR) limitation or a peak power limitation. It is shown that under a PAR limitation, it …

Energy-Constrained Quality Optimization For Secure Image Transmission In Wireless Sensor Networks, Wei Wang, Dongming Peng, Honggang Wang, Hamid Sharif, Hsiao-Hwa Chen

Department of Electrical and Computer Engineering: Faculty Publications

Resource allocation for multimedia selective encryption and energy efficient transmission has not been fully investigated in literature for wireless sensor networks (WSNs). In this article, we propose a new cross-layer approach to optimize selectively encrypted image transmission quality in WSNs with strict energy constraint. A new selective image encryption approach favorable for unequal error protection (UEP) is proposed, which reduces encryption overhead considerably by controlling the structure of image bitstreams. Also, a novel cross-layer UEP scheme based on cipher-plain-text diversity is studied. In this UEP scheme, resources are unequally and optimally allocated in the encrypted bitstream structure, including data position …

Fast Time-Varying Dispersive Channel Estimation And Equalization For 8-Psk Cellular System, Sang-Yick Leong, Jingxian Wu, Chengshan Xiao, Jan C. Olivier

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel channel-estimation scheme for an 8-PSK enhanced data rates for GSM evolution (EDGE) system with fast time-varying and frequency-selective fading channels is presented. via a mathematical derivation and simulation results, the channel impulse response (CIR) of the fast fading channel is modeled as a linear function of time during a radio burst in the EDGE system. Therefore, a least-squares-based method is proposed along with the modified burst structure for time-varying channel estimation. Given that the pilot-symbol blocks are located at the front and the end of the data block, the LS-based method is able to estimate …

A Fault-Tolerant P-Q Decoupled Control Scheme For Static Synchronous Series Compensator, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Control of nonlinear devices in power systems relies on the availability and the quality of sensor measurements. Measurements can be corrupted or interrupted due to sensor failure, broken or bad connections, bad communication, or malfunction of some hardware or software (referred to as missing sensor measurements in this paper). This paper proposes a fault-tolerant control scheme (FTCS) for a static synchronous series compensator (SSSC). This FTCS consists of a sensor evaluation and (missing sensor) restoration scheme (SERS) cascaded with a P-Q decoupled control scheme (PQDC). It is able to provide effective control to the SSSC when single or multiple crucial …

Real-Time Implementation Of A Statcom On A Wind Farm Equipped With Doubly Fed Induction Generators, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Voltage stability is a key issue to achieve the uninterrupted operation of wind farms equipped with doubly fed induction generators (DFIGs) during grid faults. A Static Synchronous Compensator (STATCOM) is applied to a power network which includes a DFIG driven by a wind turbine, for steady state voltage regulation and transient voltage stability support. The control schemes of the DFIG rotor-side converter, grid-side converter and the STATCOM are suitably designed and coordinated. The system is implemented in real-time on a Real-Time Digital Simulator (RTDS®). Results show that the STATCOM improves the transient voltage stability and therefore helps the wind turbine …

Distributed Power Control For Cellular Networks In The Presence Of Channel Uncertainties, Maciej Jan Zawodniok, Q. Shang, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel distributed power control (DPC) scheme for cellular network in the presence of radio channel uncertainties such as path loss, shadowing, and Rayleigh fading is presented. Since these uncertainties can attenuate the received signal strength and can cause variations in the received Signal-to-Interference ratio (SIR), a new DPC scheme, which can estimate the slowly varying channel uncertainty, is proposed so that a target SIR at the receiver can be maintained. Further, the standard assumption of a constant interference during a link's power update used in other works in the literature is relaxed. A CDMA-based cellular network …

Diverse Effects Of Nanosecond Pulsed Electric Fields On Mammalian Cells, Jody Anne White

Theses and Dissertations in Biomedical Sciences

The continuing effort to manipulate cell-signaling pathways for therapeutic benefit has lead to the exploration of electric field effects on cells. Current electric field applications include electroporation of the plasma membrane for introduction of drugs, genes, or other macromolecules into cells. Modeling of how these pulsed electric fields affect cells depicts the cell as an excitable circuit. In this model, the electric fields, administered in short pulses to a cell, charge the plasma and internal membranes, which act as dielectric layers, and between these the cytoplasm acts as a conductive medium. The pulse lengths of this treatment are traditionally in …

Automatic Speech Recognition Using Lp-Dctc/Dcs Analysis Followed By Morphological Filtering, Penny Hix

Electrical & Computer Engineering Theses & Dissertations

Front-end feature extraction techniques have long been a critical component in Automatic Speech Recognition (ASR). Nonlinear filtering techniques are becoming increasingly important in this application, and are often better than linear filters at removing noise without distorting speech features. However, design and analysis of nonlinear filters are more difficult than for linear filters. Mathematical morphology, which creates filters based on shape and size characteristics, is a design structure for nonlinear filters. These filters are limited to minimum and maximum operations that introduce a deterministic bias into filtered signals.

This work develops filtering structures based on a mathematical morphology that utilizes …

Optimal Phase Measuring Profilometry Techniques For Static And Dynamic 3d Data Acquisition, Veeraganesh Yalla

University of Kentucky Doctoral Dissertations

Phase measuring Profilometry (PMP) is an important technique used in 3D data acquisition. Many variations of the PMP technique exist in the research world. The technique involves projecting phase shifted versions of sinusoidal patterns with known frequency. The 3D information is obtained from the amount of phase deviation that the target object introduces in the captured patterns. Using patterns based on single frequency result in projecting a large number of patterns necessary to achieve minimal reconstruction errors. By using more than one frequency, that is multi-frequency, the error is reduced with the same number of total patterns projected as in …

Designing A Microcontroller Training Platform For Active Distance Learning Engineering And Technology Students, Steve C. Hsiung, James E. Eiland, John R. Hackworth, John Ritz

Engineering Technology Faculty Publications

This is an active distance-learning project that addresses the hands-on microprocessor/ mi-crocontroller-related courses. A research team designed a low-cost training system with supporting instructional materials to assist the teaching of these concepts. Individual laboratory activities are being developed to reinforce student learning and skill development in programming concepts. This basic system format eventually will support an array of engineering and technology courses. This project involves two community colleges, Blue Ridge Community College (BRCC) and Olympic College (OC), and a four-year university, Old Dominion University (ODU), in a collaborative research team to design and develop a specific PIC microcontroller training system …

A State-Space Approach To Blind Estimation Of Mimo Wireless Channels, Hesham Mahmoud Zarif Amin Badr

LSU Doctoral Dissertations

This dissertation focuses on blind channel estimation in wireless communications such that the estimated channel admits the minimum phase property. It assumes only the second order statistics of the transmitted signal at the receive side. Our proposed approach is based on the generalized spectral factorization because of the deficient normal rank for the power spectral density (PSD) function of the received signal. We will show the relationship between the generalized spectral factorization and inner-outer factorizations where the inner is square with smaller size. The inner-outer factorization is in turn related to the generalized Kalman filtering in which the dimension of …

Mimo-Ofdm Communication Systems: Channel Estimation And Wireless Location, Zhongshan Wu

LSU Doctoral Dissertations

In this new information age, high data rate and strong reliability features our wireless communication systems and is becoming the dominant factor for a successful deployment of commercial networks. MIMO-OFDM (multiple input multiple output-orthogonal frequency division multiplexing), a new wireless broadband technology, has gained great popularity for its capability of high rate transmission and its robustness against multi-path fading and other channel impairments. A major challenge to MIMO-OFDM systems is how to obtain the channel state information accurately and promptly for coherent detection of information symbols and channel synchronization. In the first part, this dissertation formulates the channel estimation problem …

Expanding Extracurricular Learning Opportunities Through International Engineering Student And Faculty Exchange, Mark Polczynski

Electrical and Computer Engineering Faculty Research and Publications

No abstract provided.

Computation Of Bit-Error Probabilities For Optical Receivers Using Thin Avalanche Photodiodes, Byonghyok Choi, Majeed M. Hayat

Electrical and Computer Engineering Faculty Research and Publications

The large-deviation-based asymptotic-analysis and importance-sampling methods for computing bit-error probabilities for avalanche-photodiode (APD) based optical receivers, developed by Letaief and Sadowsky [IEEE Trans. Inform. Theory, vol. 38, pp. 1162-1169, 1992], are extended to include the effect of dead space, which is significant in high-speed APDs with thin multiplication regions. It is shown that the receiver's bit-error probability is reduced as the magnitude of dead space increases relative to the APD's multiplication-region width. The calculated error probabilities and receiver sensitivities are also compared with those obtained from the Chernoff bound.

Resilient Optical Multicasting Utilizing Cycles In Wdm Optical Networks, Abhishek Satyedranath

LSU Master's Theses

High capacity telecommunications of today is possible only because of the presence of optical networks. At the heart of an optical network is an optical fiber whose data carrying capabilities are unparalleled. Multicasting is a form of communication in wavelength division multiplexed (WDM) networks that involves one source and multiple destinations. Light trees, which employ light splitting at various nodes, are used to deliver data to multiple destinations. A fiber cut has been estimated to occur, on an average, once every four days by TEN, a pan-European carrier network. This thesis presents algorithms to make multicast sessions survivable against component …

Exploring The Hot-Carrier Effect On The Wireless Transceivers, Sameer R. Herlekar

LSU Doctoral Dissertations

Phase noise can be regarded as the most severe cause of performance degradation in the wireless communication systems. The hot-carriers (HCs), found in the CMOS synchronization circuits, are the high-energy charge carriers that degrade the MOSFET devices’ performance by increasing the threshold voltage required to operate the MOSFETs. The HC effect manifests itself as the phase noise whose level increases with the continued MOSFET operation and such increases result in the performance degradation of the voltage-controlled oscillator (VCO) built on the MOSFETs. The HC effect is particularly evident in the short-channel MOSFET devices. In this dissertation, we analyze the wireless …

Optical Control Plane: Theory And Algorithms, Stefan Alexandru Pascu

LSU Doctoral Dissertations

In this thesis we propose a novel way to achieve global network information dissemination in which some wavelengths are reserved exclusively for global control information exchange. We study the routing and wavelength assignment problem for the special communication pattern of non-blocking all-to-all broadcast in WDM optical networks. We provide efficient solutions to reduce the number of wavelengths needed for non-blocking all-to-all broadcast, in the absence of wavelength converters, for network information dissemination. We adopt an approach in which we consider all nodes to be tap-and-continue capable thus studying lighttrees rather than lightpaths. To the best of our knowledge, this thesis …

Performance Of Torus-Type Brushless Dc Motor With Winding Connected In Two And Three-Phase System, Dinakar Choppa

LSU Master's Theses

A torus-type permanent magnet brushless DC motor is the object of this thesis. The motor can operate with the winding connected either in two - phase or three - phase system. A comparative study of performance of the motor operating in these two systems is the objective of the thesis. To analyze the motor performance, the dynamic models of the motors operating with two - phase and three - phase motors have been proposed. The simulation of motor operation was carried out using the MATLAB/SIMULINK software package. A study of motors operation in steady state conditions has been done by …

A Configurable Decoder For Pin-Limited Applications, Matthew Collin Jordan

LSU Master's Theses

Pin limitation is the restriction imposed on an IC chip by the unavailability of a sufficient number of I/O pins. This impacts the design and performance of the chip, as the amount of information that can be passed through the boundary of the chip becomes limited. One area that would benefit from a reduction of the effect of pin limitation is reconfigurable architectures. In this work, we consider reconfigurable devices called Field Programmable Gate Arrays (FPGAs). Due to pin limitation, current FPGAs use a form of 1-hot decoder to select elements (one frame at a time) during partial reconfiguration. This …

Designing Switches For Routing In Circuit-Switched Trees, Dinesh Prasad Venkat Rao

LSU Master's Theses

Reconfigurable computing provides a fast and flexible solution for intensive computing processes. Thus, it acts as a bridge between software controlled and hardware based processors. The self–reconfigurable gate array (SRGA) is a reconfigurable architecture that allows fast switching between operations on a reconfigurable device. It consists of a 2-dimensional array of processing elements (PEs) connected using a binary tree structure, called a circuit-switched tree (CST). A CST is a balanced binary tree in which leaves represent processing elements (PE) and internal nodes represent switches. The PEs in the CST communicates with each other by configuring the appropriate switches in the …

Em Algorithm For Multiple Wideband Source Localization, Kiran Kumar Mada

LSU Master's Theses

A computationally efficient algorithm using the expectation-maximization (EM) algorithm for multiple wideband source localization in the near field of a sensor array/area is addressed in this thesis. Our idea is to decompose the observed sensor data, which is a superimposition of multiple sources, into the individual components in the frequency domain and then estimate the corresponding location parameters associated with each component separately. Instead of the conventional alternating projection (AP) method, we propose to adopt the EM algorithm in this work; our new method involves two steps, namely Expectation (E-step) and Maximization (M-step). In the E-step, the individual incident source …

Design Of Linear Boolean Network Codes For Combination Networks, Shoupei Li

LSU Master's Theses

Network coding is a promising technique to improve the throughput of communication networks. In the thesis, we investigate linear Boolean network codes on a special class of multicast networks, called combination networks. Using companion matrices of primitive polynomials over finite fields, we design a class of symmetric linear Boolean network codes from Reed-Solomon codes for single-source combination networks. We also prove that, for some cases, the linear Boolean network codes are optimal in the sense of minimum network uses. In the thesis, we further consider two-source network coding problem for combination networks and other specific networks. We develop a method …

A Fast Parallelized Computational Approach Based On Sparse Lu Factorization For Predictions Of Spatial And Time-Dependent Currents And Voltages In Full-Body Biomodels, Ashutosh Mishra, Ravindra P. Joshi, Karl H. Schoenbach, C. D. Clark Iii

Electrical & Computer Engineering Faculty Publications

Realistic and accurate numerical simulations of electrostimulation of tissues and full-body biomodels have been developed and implemented. Typically, whole-body systems are very complex and consist of a multitude of tissues, organs, and subcomponents with diverse properties. From an electrical standpoint, these can be characterized in terms of separate conductivities and permittivities. Accuracy demands good spatial resolution; thus, the overall tissue/animal models need to be discretized into a fine-grained mesh. This can lead to a large number of grid points (especially for a three-dimensional entity) and can place prohibitive requirements of memory storage and execution times on computing machines. Here, the …

Intercarrier Interference Suppression For The Ofdm Systems In Time-Varying Multipath Fading Channels, Xiaozhou Huang

LSU Doctoral Dissertations

Due to its spectral efficiency and robustness over the multipath channels, orthogonal frequency division multiplexing (OFDM) has served as one of the major modulation schemes for the modern communication systems. In the future, the wireless OFDM systems are expected to operate at high carrier-frequencies, high speed and high throughput mobile reception, where the fasting time-varying fading channels are encountered. The channel variation destroys the orthogonality among the subcarriers and leads to the intercarrier interference (ICI). ICI poses a significant limitation to the wireless OFDM systems. The aim of this dissertation is to find an efficient method of providing reliable communication …

A Study Of Phase Noise And Jitter In Submicron Cmos Phase-Locked Loop Circuits, Chi Zhang

LSU Doctoral Dissertations

Phase-locked loops (PLLs) are widely used in communication systems. With the continuously expanding of market for high speed, portable communication devices, low noise CMOS submicron integrated circuit designs of PLL for different applications are in large demand. In this dissertation, phase noise and jitter properties of PLL and its building blocks are investigated both at the physical and system levels. At the physical level, hot carrier effect in submicron MOSFETs has been considered. As one of the most dominant noise sources of PLL, the voltage-controlled oscillator (VCO) is considered when investigating the noise degradation induced by the hot carrier effect. …

Instantaneously Trained Neural Networks With Complex And Quaternion Inputs, Adityan V. Rishiyur

LSU Master's Theses

Neural network architectures such as backpropagation networks, perceptrons or generalized Hopfield networks can handle complex inputs but they require a large amount of time and resources for the training process. This thesis investigates instantaneously trained feedforward neural networks that can handle complex and quaternion inputs. The performance of the basic algorithm has been analyzed and shown how it provides a plausible model of human perception and understanding of images. The motivation for studying quaternion inputs is their use in representing spatial rotations that find applications in computer graphics, robotics, global navigation, computer vision and the spatial orientation of instruments. The …

A Tabu Search Algorithm To Minimize The Makespan For The Unrelated Parallel Machines Scheduling Problem With Setup Times, Magdy Helal, Ghaith Rabadi, Ameer Al-Salem

Engineering Management & Systems Engineering Faculty Publications

In this paper we propose a tabu search implementation to solve the unrelated parallel machines scheduling problem with sequence- and machine- dependent setup times to minimize the schedules makespan. The problem is NP-hard and finding an optimal solution efficiently is unlikely. Therefore, heuristic techniques are more appropriate to find near-optimal solutions. The proposed tabu search algorithm uses two phases of perturbation schemes: the intra-machine perturbation, which optimizes the sequence of jobs on the machines, and the inter-machine perturbation, which balances the assignment of the jobs to the machines. We compare the proposed algorithm to an existing one that addressed the …

Cooperative Forest Fire Surveillance Using A Team Of Small Unmanned Air Vehicles, Randal Beard, David Casbeer, Derek Kingston, Timothy W. Mclain, Sai-Ming Li, Raman Mehra

Faculty Publications

This research was supported by NASA under STTR contract No. NNA04AA19C to Scientific Systems Company, Inc (SSCI) and Brigham Young University (BYU), and by AFOSR grants F49620-01-1-0091 and F49620-02-C- 0094. The objective of this paper is to explore the feasibility of using multiple low-altitude, short endurance (LASE) unmanned air vehicles (UAVs) to cooperatively monitor and track the propagation of large forest fires. A real-time algorithm for tracking the perimeter of a fire with an on-board infrared sensor is developed. Using this algorithm, we develop a decentralized multiple-UAV approach to monitoring the perimeter of the fire. The UAVs are assumed to …