Digital Commons Network^™

Construction Of Short-Length High-Rates Ldpc Codes Using Difference Families, Deny Hamdani, Ery Safrianti

Makara Journal of Technology

Low-density parity-check (LDPC) code is linear-block error-correcting code defined by sparse parity-check matrix. It is decoded using the massage-passing algorithm, and in many cases, capable of outperforming turbo code. This paper presents a class of low-density parity-check (LDPC) codes showing good performance with low encoding complexity. The code is constructed using difference families from combinatorial design. The resulting code, which is designed to have short code length and high code rate, can be encoded with low complexity due to its quasi-cyclic structure, and performs well when it is iteratively decoded with the sum-product algorithm. These properties of LDPC code are …

Ncl Implementation Of Dual-Rail 2S Complement 8x8 Booth2 Multiplier Using Static And Semi-Static Primitives, Mandar V. Joshi, Sagar R. Gosavi, V. Jegadeesan, A. Basu, S. Jaiswal, Waleed K. Al-Assadi, Scott C. Smith

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, we use static and semi-static versions of NULL Convention Logic (NCL) primitives (i.e., threshold gates) to implement a dual-rail 8times8 2s complement multiplier using the Modified Booth2 algorithm for partial product generation and a Wallace tree for partial product summation. We establish the multiplier's functionality utilizing VHDL-based simulations of the gate-level structural design. The design is then implemented at the transistor-level and layout-level using both static and semi-static threshold gates, for a 1.8V 0.18mum TSMC CMOS process; and these two implementations are compared in terms of area, power, and speed.

Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet

Electrical & Computer Engineering Theses & Dissertations

Wireless Local Area networks (WLAN) and Wireless Personal Area Networks (WPAN) provide complimentary services using the same unlicensed radio frequency band of operation. The 802.11b WLAN operates in the 2.4 GHz band and uses a Direct Sequence Spread Spectrum technique. It is designed to cover large areas ranging up to 100 meters in diameter, which may connect hundreds of computers. Bluetooth (BT) WPAN also operates in the same frequency band as the IEEE 802.lib and it uses a Frequency Hopping Spread Spectrum technique. BT is primarily used for communications between notebooks, palm units and other personal computing devices within relatively …

Detecting Compromised Nodes In Wireless Sensor Networks, Mary Lisa Mathews

Electrical & Computer Engineering Theses & Dissertations

While wireless sensor networks are proving to be a versatile tool, many of the applications in which they are utilized have sensitive data. Therefore, security is crucial in many of these applications. Once a sensor node has been compromised, the security of the network degrades quickly if measures are not taken to deal with this event. There have been many approaches researched to tackle the issue. In this thesis, an anomaly-based intrusion detection protocol is developed to detect compromised nodes in wireless sensor networks.

The proposed protocol is implemented after the sensors are deployed into the environment in which they …

Application Of Neural Networks For Data Modeling Of Power Systems With Time Varying Nonlinear Loads, Joy Mazumdar, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Nowadays power distribution systems typically operate with nonsinusoidal voltages and currents. Harmonic currents from nonlinear loads propagate through the system and cause harmonic pollution. The premise of IEEE 519 is that there exists a shared responsibility between utilities and customers regarding harmonic control. Maintaining reasonable levels of harmonic voltage distortion depends upon customers limiting their harmonic current injections and utilities controlling the system impedance characteristics. Measurements of current taken at the point of common coupling (PCC) to a customer are expected to determine whether the customer is in compliance with IEEE 519. These measurements yield the combination of nonlinear load …

Effects Of Ocean Thermocline Variability On Noncoherent Underwater Acoustic Communications, Martin Siderius, Michael B. Porter, Paul Hursky, Vincent Mcdonald

Electrical and Computer Engineering Faculty Publications and Presentations

The performance of acoustic modems in the ocean is strongly affected by the oceanenvironment. A storm can drive up the ambient noise levels, eliminate a thermocline by wind mixing, and whip up violent waves and thereby break up the acoustic mirror formed by theocean surface. The combined effects of these and other processes on modem performance are not well understood. The authors have been conducting experiments to study these environmental effects on various modulation schemes. Here the focus is on the role of the thermocline on a widely used modulation scheme (frequency-shift keying). Using data from a recent experiment conducted …

The Distributed Independent-Platform Event-Driven Simulation Engine Library (Diesel), Reejo Mathew

Electrical & Computer Engineering Theses & Dissertations

The Distributed, Independent-Platform, Event-Driven Simulation Engine Library (DIESEL) is a simulation executive, capable of supporting both sequential and distributed discrete-event simulations. A system level specification is provided along with the expected behavior of each component within DIESEL. This behavioral specification of each component, along with the interconnection and interaction between the different components, provides a complete description of the DIESEL behavioral model. The model provides a considerable amount of freedom for an application developer to partition the simulation model, when building sequential and distributed applications with respect to balancing the number of events generated across different components. It also allows …

Rotating Or Rotatable Compensator Spectroscopic Ellipsometer System Including Multiple Element Lenses, Blaine D. Johs, Martin M. Liphardt, Jeffrey S. Hale, Craig M. Herzinger, Steven E. Green, Ping He, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed are spectroscopic ellipsometer systems which include polarizer and analyzer elements which remain fixed in position during data acquisition, and at least one continuously rotating or step-wise rotatable compensator which transmits an electromagnetic beam therethrough and imposes a continuously variable or plurality of sequentially discrete polarization states on a beam of electromagnetic radiation; and at least one multiple element lens which also transmits the electromagnetic beam therethrough.

Semi Autonomous Vehicle Intelligence: Real Time Target Tracking For Vision Guided Autonomous Vehicles, Jonathan D. Anderson

Theses and Dissertations

Unmanned vehicles (UVs) are seeing more widespread use in military, scientific, and civil sectors in recent years. These UVs range from unmanned air and ground vehicles to surface and underwater vehicles. Each of these different UVs has its own inherent strengths and weaknesses, from payload to freedom of movement. Research in this field is growing primarily because of the National Defense Act of 2001 mandating that one-third of all military vehicles be unmanned by 2015. Research using small UVs, in particular, is a growing because small UVs can go places that may be too dangerous for humans. Because of the …

Point Spread Function Characterization Of A Radially Displaced Scatterer Using Circular Synthetic Aperture Radar, Uttam K. Majumder

Theses and Dissertations

This research effort investigated characterizing the point spread function (PSF) behavior of radially displaced point scatterers using circular synthetic aperture radar (CSAR). Thus far, research has been conducted to understand PSF of a scatterer located at the imaging scene center. An analytic closed-form solution has been derived assuming the scatterer is located at the origin of the CSAR imaging geometry. However, it is difficult to derive an analytic PSF solution for a scatterer that is radially displaced from the imaging scene center. Using the back projection image formation algorithm, PSF responses are generated at various point target locations. Consistent with …

Optical Tracking For Relative Positioning In Automated Aerial Refueling, James H. Spencer

Theses and Dissertations

An algorithm is designed to extract features from video of an air refueling tanker for use in determining the precise relative position of a receiver aircraft. The algorithm is based on receiving a known estimate of the tanker aircraft's position and attitude. The algorithm then uses a known feature model of the tanker to predict the location of those features on a video frame. A corner detector is used to extract features from the video. The measured corners are then associated with known features and tracked from frame to frame. For each frame, the associated features are used to calculate …

Analysis Of Stacked Rotated Gratings, Gregory P. Nordin, P. C. Deguzman, J. Jiang

Faculty Publications

We study the rigorous design and analysis of stacked rotated gratings (SRGs) for novel photonic devices. A concept of sampling frequency is proposed to systematically design SRGs. With the help of a rectangular sampling lattice, we extend the standard 3D rigorous coupled-wave analysis (RCWA) algorithm to the analysis of SRGs. The resultant SRG-RCWA algorithm can be used to exactly analyze SRGs that have grating parameters that match the Fourier expansion represented by the sampling lattice. SRGs that do not fall in this category can often still be closely approximated with our approach. The SRG-RCWA algorithm has been successfully applied to …

Phase Diversity And Polarization Augmented Techniques For Active Imaging, Peter M. Johnson

Theses and Dissertations

A multi-frame active phase diversity imaging (APDI) algorithm is derived for coherent light statistics and demonstrated. In addition to conventional focal-plane and diversity-plane data, a statistical description for pupil-plane (PP) intensity is formed and included in the derivation. The algorithm is implemented and characterized via Monte Carlo simulation. Analysis shows that it's robust, insensitive to detection noise for SNR ? 7, performs well for SNR's as low as 2, and that the effect of system configuration on optimal parameters is minimal. Furthermore, introduction of PP data results in a 60% better reconstruction from dynamically aberrated data than obtained using only …

Circuit And Modeling Solutions For High-Speed Chip-To-Chip Communication, Timothy Mowry Hollis

Theses and Dissertations

This dissertation presents methods for modeling and mitigating voltage noise and timing jitter across high-speed chip-to-chip interconnects. Channel equalization and associated tuning schemes have been developed to target the distinct characteristics and signal degradation exhibited in the clock and data signals of multi-Gigabit/second digital communication links. Multiple methods for generating realistically degraded signals for the purpose of simulation are also presented and used to verify the proposed equalization and filtering topologies. Specifically, a new technique for modeling high-speed jittery clocks in the frequency domain is presented and shown to reduce transient simulation time and memory requirements, while simultaneously improving the …

Investigation Of Gate Current In Neutron Irradiated AlXGa1-XN/Gan Heterogeneous Field Effect Transistors Using Voltage And Temperature Dependence, Thomas E. Gray

Theses and Dissertations

The gate current of Al₂₇Ga₇₃N/GaN heterogeneous field effect transistors (HFETs) is investigated using current-voltage (IV) and current-temperature (IT) measurement demonstrating that trap assisted tunneling (TAT) is the primary current mechanism. A thermionic trap assisted tunneling (TTT) model is used with variables of Schottky barrier height, trap energy, donor density and trap density. This results in a sigma of 1.38x10^-8 A for IT data measured between 85K and 290K and for IV data measured between 0.0 V and -4.0 V. High energy (>0.5 MeV) neutron irradiation confirms an increase of gate current with fluence. An …

Optimal Sensor Threshold Control And The Weapon Operating Characteristic For Autonomous Search And Attack Munitions, Roland A. Rosario

Theses and Dissertations

This Thesis considers the optimal employment of a wide area search munition in a battlespace where a target is known to be uniformly distributed among false targets which are Poisson distributed. The Poisson distribution's parameter is obtained from readily available battlespace intelligence. This work formulates and solves the optimal control problem for deriving the optimal sensor threshold schedule in order to maximize the probability of attacking the target during the battlespace sweep while constraining the probability of attacking a false target. The efficiency gained by optimally varying the sensor threshold is compared against the performance achieved with a static, optimum …

A Modular Mixed Signal Vlsi Design Approach For Digital Radar Applications, Brian M. Brakus

Theses and Dissertations

This study explores the idea of building a library of VHDL configurable components for use in digital radar applications. Configurable components allows a designer to choose which components he or she needs and configures those components for a specific application. By doing this, design time for ASICs and FPGAs is shortened because the components are already designed and tested. This idea is demonstrated with a configurable dynamic pipelinable fast fourier transform. Many FFT implementations exist, but this implementation is both configurable and dynamic. Pre-synthesis customization allows the FFT to be tailored to almost any DSP application, and the dynamic property …

Characterizationn Of Polumer-Based Mems Pyroelectic Infrared Detector, Mark E. Allard

Theses and Dissertations

AFRL/MLPJE had developed a novel thermal sensing material termed protein-impregnated-polymer (PIP). Thus far, a proof-of-concept has been demonstrated using a macro-sized pixel (0.64 mm²) as a bolometric detector. In an effort to better characterize this novel thermal sensing material, experimental data was used to determine figures of merit (FOMs) comparative to off-the-shelf thermal detectors. Microelectromechanical (MEMS) pixels were designed and used as the support structure for an inkjet-deposited droplet of the PIP. During the material characterization, two observations were made: PIP is a pyroelectric material, and the polymer (polyvinyl alcohol (PVA)) without the protein was found to be …

Multi-Dimensional Classification Algorithm For Automatic Modulation Recognition, Ouail Albairat

Theses and Dissertations

This thesis proposes an approach for modulation classification using existing features in a more efficient way. The Multi-Dimensional Classification Algorithm (MDCA) treats features extracted from signals of interest as elements with irrelevant identities, hence eliminating any dependence of the classifier on any particular feature. This design enables the use of any number of features, and the MDCA algorithm provides the capability to classify modulations in higher dimensions. The use of multiple features requires an equal number of data dimensions, and thus classification in as high a dimensional space as possible can improve final classification results. Finally, the MDCA algorithm uses …

Thermally Activated, Variable Blazed Grating For Coherent Beam Steering, Matthew T. Johnson

Theses and Dissertations

The ability to perform non-mechanical optical beam steering is of critical importance in laser communication and remote sensing; it is as vital as a phased-array antenna is for RADAR. Directed energy transmission and direction-selective reception increase performance and produce tactical advantage in DoD applications. However, specific geometric features of non-mechanical beam steering devices must be designed in proportion to the wavelength of the monochromatic light to be steered. Also, the ability to handle higher energies by reducing the energy per unit requires large areas of uniform properties on the micrometer scale. These challenges have been addressed in the past using …

Material Characterization Improvement In High Temperature Rectangle Waveguide Measurements, Eric A. Buschelman

Theses and Dissertations

This research presents a method by which electromagnetic characterization of materials in a partially filled waveguide can be accurately performed. Higher order modes are excited by the geometry, which are not accounted for in most algorithms. A correction must consider the power transmitted by higher-order modes. Modal solutions, using reference plane independence, for a single top air gap between the material sample and the waveguide wall, are also presented. Characterization is performed on samples of acrylic and rubberized magnetic radar absorbing material. Calculation of the complex permittivity and permeability of shielding material, within 10% of the true value, was achieved …

Sub-Surface Navigation Using Very-Low Frequency Electromagnetic Waves, Alan L. Harner

Theses and Dissertations

This research proposes two schemes utilizing very-low frequency (VLF) electromagnetic waves to navigate underground. The first scheme consists of using above-ground beacon transmitters to broadcast VLF signals to an underground mobile receiver which uses methods such as triangulation and trilateration to obtain a position solution. The second scheme consists of using above-ground reference receivers along with an underground mobile receiver to form time-difference- of-arrival measurements of incoming VLF signals of opportunity, such as lightning strike emissions, to calculate a position solution. The objective of this thesis is to develop positioning algorithms and use simulations as a tool to characterize the …

Biological Cell Identification By Integrating Micro-Fluidics, Electrical Impedance Spectroscopy And Stochastic Estimation, Karl R. Schwenn

Theses and Dissertations

The integration of micro-fluidics, electrical impedance spectroscopy and stochastic estimation will lead to a device with enhanced detection capabilities. The goal of this thesis was to build a micro-fluidic electrical impedance measurement device that can be used in combination with a stochastic estimator to accurately identify living cells. A microdevice capable of making impedance measurements on individual living cells was designed and built using a series of standard microelectronic fabrication techniques. A microchannel was patterned in SU-8 photoresist between two gold microelectrodes on a two inch Pyrex 7740 wafer. The design process, the fabrication techniques for the microchannel, the fluid …

Teaching And Learning Dc‐Dc Converter Design Using Mathcad, Taufik

Electrical Engineering

This paper presents an approach for teaching and learning dc-dc converter design using MathCAD. MathCAD provides advantages that greatly improve teaching and learning process especially when long and complicated design equations are involved such as those found in dc-dc converters. A design example using Excel is presented and then compared with the same example using MathCAD. Experience learned from using MathCAD in power electronic courses at Cal Poly will be discussed in this paper.

A Multidisciplinary Design Project In Energy Conversion Electromagnetics Course, Ali Shaban, Ahmad Nafisi, Fred Depiero, Taufik

Electrical Engineering

This paper presents a work-in-progress on a new multidisciplinary design project for an Energy Conversion Electromagnetics course at Cal Poly State University. The project is intended to strengthen the skills of electrical and mechanical engineering students by performing design tasks in a multidisciplinary environment. Concurrently, this new design project is implemented to fulfill ABET criterion 3d. The content and format of the project will be described in this paper. Assessments planned for the project will also be discussed.

Dynamic Voltage Restorer For Sensitive Equipment, Yea Zong Kuo

Electrical Engineering Dissertations - Archive

Voltage sags are considered to be the most frequent type of disturbances in the field based on recent power disturbances studies. Their impact on sensitive loads is severe. The impact ranges from load disruptions to substantial economic losses. Despite the technical advances in electronics, there are still some pieces of equipment that are so sensitive that they are unable to withstand voltage sags. An example is the equipment in semiconductor manufacturing. As a result, there is still a search for different ways to manage voltage sags. There are many different methods to mitigate voltage sags, but a CUstom Power Supply …

Sampled-Data Kalman Filtering And Multiple Model Adaptive Estimation For Infinite-Dimensional Continuous-Time Systems, Scott A. Sallberg

Theses and Dissertations

Kalman filtering and multiple model adaptive estimation (MMAE) methods have been applied by researchers in several engineering disciplines to a multitude of problems featuring a linear (or mildly nonlinear) model based on finite-dimensional differential (or difference) equations perturbed by random inputs. However, many real-world systems are more naturally modeled using an infinite-dimensional continuous-time linear systems model, such as those most naturally modeled as partial differential equations or time-delayed differential equations along with a possibly infinite-dimensional measurement model. The Kalman filtering technique was extended to encompass infinite-dimensional continuous-time systems with sampled-data measurements and a technique to approximate an infinite-dimensional continuous-time system …

Automatic Target Recognition User Interface Tool, David A. Kerns

Theses and Dissertations

A computer tool to aid in selecting the best Automatic Target Recognition (ATR) algorithm is developed. The program considers many quantifiers, accepts user-defined parameters, allows for changes in the operational environment and presents results in a meaningful way. It is written for Microsoft Excel. An ATR algorithm assigns a class label to a recognized target. General designations can include "Friend" and "Foe." The error of designating "Friend" as "Foe" as well as "Foe" as "Friend" comes with a high cost. Studying each algorithm's error can minimize this cost. Receiver Operating Characteristic (ROC) curves provide only information on the probabilities given …

Using Relocatable Bitstreams For Fault Tolerance, David P. Montminy

Theses and Dissertations

This research develops a method for relocating reconfigurable modules on the Virtex-II (Pro) family of Field Programmable Gate Arrays (FPGAs). A bitstream translation program is developed which correctly changes the location of a partial bitstream that implements a module on the FPGA. To take advantage of relocatable modules, three fault-tolerance circuit designs are developed and tested. This circuit can operate through a fault by efficiently removing the faulty module and replacing it with a relocated module without faults. The FPGA can recover from faults at a known location, without the need for external intervention using an embedded fault recovery system. …

Nonlinear Time-Variant Response In An Avalanche Photodiode Array Based Laser Detection And Ranging System, Michael D. Seal

Theses and Dissertations

This research effort identifies and models the nonlinear time-variant behavior exhibited by an avalanche photodiode (APD) array based Laser Ranging and Detection (LADAR) system. Based on the original Linear Time-Invariant (LTI) model, the evolution of error in the LADAR signal is examined sequentially from the outgoing pulse through signal digitization. This error evolution shows that the LTI model does not contain a mechanism for causing the observed signal deviations or the failure to meet the Cramer-Rao lower bound for range accuracy. A nonlinear time-variant model is developed based on the interactions of the avalanche photodiodes in the array with the …