Engineering Commons^™

Array Analysis Of Radio Frequency Interference Cancelation Requirements For A Land Mine Detection System, Devin Baker Pratt

Theses and Dissertations

Land mines are a major humanitarian problem with millions of active mines in place around the world. Since these mines can have little metal in them, novel detection techniques are needed. Nuclear Quadrupole Resonance (NQR) is one such technique. Unfortunately, NQR is highly succeptible to radio frequency interference (RFI). A significant contribution of this thesis is the development of a custom, experimental data acquisition system designed and built specifically for capturing RFI at frequencies significant to NQR land mine detection systems. Another major contribution is the development of data analysis techniques for determining the number of reference antennas required to …

Eigenspace Model Based Error Concealment And Low Bit Rate Coding Of Face Sequences, Xuejun Hu

Electrical Engineering Dissertations

The emerging multimedia applications address the increasing demand for novel video coding systems to provide higher compression ratio while maintaining the high quality of the reconstruction. This research makes an effort under such context to investigate the application of principal component analysis (PCA) in the video coding area, especially for error concealment and very low bit rate face coding. PCA is a well known optimal linear scheme for dimension reduction in data analysis. The central idea of PCA is to reduce the dimensionality of a data set while retaining as much as possible the variation in the data set. Since …

Optimization Of H.264 Baseline Decoder On Arm9tdmi Processor, Sandya B. Sheshadri

Electrical Engineering Theses

With the newly introduced features and advancements to the pre-existing features, the emerging H.264 video coding standard achieves significant improvements in coding performance over all existing standards, in a wide variety of applications. The coding-efficiency advantages of H.264, however, come at the expense of higher computational complexity. H.264 decoders can exhibit more than double the complexity of H.263 decoders. Furthermore, previous studies have shown that fractional-pixel motion-compensation interpolation and the loop filtering consume a significant amount of computational power in emerging H.264 decoders. Since these operations are part of the baseline profile of H.264, there is a need to evaluate …

Region Of Interest (Roi) Based Rate Control For H.263 Compatible Video Conferecing, Lin Tong

Electrical Engineering Dissertations

This dissertation presents a region of interest (ROI) based H.263 [10] [13] compatible video codec, which integrates the idea of object-based coding from MPEG-4 Visual [9] [15] into the traditional block-based H.263 codec. A face detection and tracking scheme with very low complexity is proposed to segment human face region from video conferencing sequences in real-time. For intra frames, the proposed detection method is a hybrid skin color and mosaic-rule based face detection and for inter frames the face tracking method uses motion vectors only. With the segmentation information, the ROI based codec and its associated rate control schemes are …

A Cmos Ultra-Wideband Differential Low Noise Amplifier, Timothy Bryan Merkin

Electrical Engineering Theses

In this thesis, a CMOS Ultra-wideband (UWB) Low noise Amplifier (LNA) was designed and simulated. In the design, specific architecture decisions were made in consideration of ultimately including this LNA in a system-on-chip implementation of an Ultra-wideband communication system. The basic architecture of the LNA designed herein exhibits a differential amplifier core with active input and output impedance matching, minimizing the number of expensive space consuming passive inductors necessary for passive impedance matching networks. The LNA maintains a gain of 16.4dB with a ±0.25dB ripple over the band of 3.1-6.2GHz. Despite the use of an active input matching stage, the …

Error-Resilient Image And Video Coding Over Lossy Networks, Yilong Liu

Electrical Engineering Dissertations

The rapid growth of the Internet and increasing bandwidth in the past decade has heightened the interest in robust transmission of image and video signals over error-prone links. Recent literatures highlight the multiple description (MD) coding as a promising approach to solve this problem. MD coding is a source coding technique that provides a graceful quality degradation in the presence of packet losses during transmission. Topics of interest to construct MD coders with high coding efficiency and robustness are studied in this thesis. First, to minimize the overall distortion of reconstructed image, an edge-adaptive estimation algorithm is employed, which can …

Cmos 5th Derivative Gaussian Impulse Generator For Uwb Application, Shin-Chih Chang

Electrical Engineering Theses

A complete impulse generating system was designed and simulated which generates the fifth order derivative of the Gaussian pulse intended for use in an impulse-type ultra-wideband wireless communication system. By using a continuous-time FIR impulse shaping filter, the system transforms a normal Gaussian pulse signal obtained from an existing CMOS Gaussian pulse generator into its fifth derivative. The transformation filtering was accomplished without lengthening the time duration of the original pulse or causing any noticeable ringing effects. The final output waveform closely resembles the fifth derivative of the Gaussian pulse, and also satisfies the spectral mask emission requirements specified by …

A Simulation Tool Suite For The Modeling And Optimization Of Multiple Quantum Well Structures, Jeffery Wayne Allen

Electrical Engineering Theses

This thesis aims to develop a suite of computational tools for design, analysis, and simulation of semiconductor multiple quantum well structures with a user-friendly GUI. The research project focuses on the electrical and optical aspects of user defined quantum well structures, and allows the user to vary design parameters to optimize the structure for different device applications and functionality. Specifically the thesis delves into the design and analysis of different quantum well structures as they relate to band gap engineering. Key features of this computational suite include relationship to electrical field, doping profiles and optical transitions. The quantum well structures …

Integrated High Speed Intelligent Utility Tie Unit For Disbursed/Renewable Generation Facilities, Worakarn Wongsaichua

Electrical Engineering Dissertations

After experiencing the price hikes and rotating blackouts in California, the disbursed or distributed generation (DG) is considered as one of the most attractive alternatives for future utility industry. In addition to the conventional DG that uses fossil-fuel to generate power, the DG via renewable energy is of interest due to the environmental concern. Fuel cell and photovoltaic are the most promising technologies for the urban residential and small commercial users. For economic and reliability purposes, it is desirable for these facilities to be interconnected with the utility grid to perform peak shaving, demand reduction, and to serve as emergency …

Optimization Of H.264 High Profile Decoder For Pentium 4 Processor, Tarun Bhatia

Electrical Engineering Theses

H.264 is an emerging video coding standard, which aims at compressing high-quality video content at low-bit rates. While the basic idea behind the encoding and decoding process still remains the same as in the previous standards, many new and innovative tools have been added to provide higher compression capabilities with high perceptual quality. These capabilities have also contributed to the increase in complexity of implementation of H.264 significantly compared to the previous generation of video coding standards. In this thesis, the performance analysis of the H.264 decoder for decoding of high profile high definition data is done for the Pentium …

Modeling And Feedback Control Of Mems Devices, Bruno Borovic

Electrical Engineering Dissertations

As MEMS actuators reach maturity and emerge from the research lab into commercial applications, their increased reliability, speed, and performance accuracy is needed. MEMS are typically driven directly in an open-loop fashion by applying simple actuating signals. The requirements for better dynamical behavior, however, have resulted in the gradual introduction of improved actuation approaches, such as pre-shaped open-loop driving and closed-loop control. Unlike macro mechanical systems where the implementation of the feedback is relatively simple, it is quite problematic in the MEMS case. The presence of fast system dynamics, and physical area efficiency requirements have introduced additional challenges for feedback …

A Patterning Process Utilizing A Nanoimprint Lithography For Fabrication Of Planar Perpendicular Patterned Magnetic Media, Robert Grove Iii

Theses and Dissertations

This thesis describes the results of applied research in the area of patterned magnetic media. Current magnetic media is pushing the physical limits of magnetic bits by compressing them into very small spaces - a process that will eventually be hampered by the superparamagnetic effect. The superparamagnetic effect will require the magnetic media industry to find a modified method of storing magnetic bits. Perpendicular patterned magnetic media could be the method of choice for future generations of magnetic data storage. Patterning magnetic media allows bits to be stored in isolated magnetic islands instead of in a continuous magnetic surface, as …

Design And Development Of Poly -(3 -Hexylthiophene) Field Effect Transistors, Fengliang Xue

Doctoral Dissertations

Organic field effect transistors (OFETs) with poly(3-hexylthiophene) (P3HT) as the active layer are developed and studied. The device characteristics are significantly affected by source/drain contact resistance, and P3HT-SiO 2 interface and the traps. These results are verified by the numerical device simulations. The temperature dependence of device mobility is studied, which indicates that the carrier transport is either heat-assisted or heat-limited at different temperature ranges. The on/off ratio and threshold voltage are found to be dependent on the temperature. Hysteresis effect due to gate electric stress is investigated. The silanol groups present at the SiO2 surface are thought to be …

The Development Of A Small Scale Radio Astronomy Image Synthesis Array For Research In Radio Frequency Interference Mitigation, Jacob L. Campbell

Theses and Dissertations

Radio astronomy synthesis imaging arrays are composed of many parabolic reflector antennas. These antennas are designed to be extremely sensitive to detect faint emissions from astronomical sources. Unfortunately, this also makes them susceptible to radio frequency interference (RFI) from man made sources such as orbiting satellites. The radio astronomy research group at Brigham Young University (BYU) is investigating methods to mitigate the effects of RFI in radio astronomy synthesis imaging. Though real-time RFI mitigation has been demonstrated for a large single dish telescope, for synthesis imaging arrays our prior work has consisted solely of algorithm development and computer simulations. To …

Nonlinear Regression Methods For Estimation, Eric B. Nelson

Theses and Dissertations

Regression techniques are developed for batch estimation and applied to three specific areas, namely, ballistic trajectory launch point estimation, adaptive flight control, and radio-frequency target triangulation. Specifically, linear regression with an intercept is considered in detail. An augmentation formulation is developed. Extensions of theory are applied to nonlinear regression as well. The intercept parameter estimate within the linear regression is used to identify the effects of trim change that are associated with the occurrence of a control surface failure. These estimates are used to adjust the inner loop control gains via a feed-forward command, hence providing an automatic reconfigurable retrim …

Protein Impregnated Polymer (Pip) Film Infrared Sensor Using Suspended Microelectromechanical Systems (Mems) Pixels, Tetsuo Kaieda

Theses and Dissertations

The Air Force Research Laboratory Materials and Manufacturing Directorate have developed a novel protein impregnated polymer (PIP) suspension that changes resistivity as a function of absorbed infrared radiation. Due to this property, the PIP is a potential material for use as an uncooled bolometer, or thermal sensor. In this research, a thermally-isolated pixel design, sensor characterization methods, and sensor fabrication and processing steps were developed. To create a microbolometer, the PIP was applied to two prototype micro-electro-mechanical systems (MEMS) surface micro-machined structures. The first is a raised cantilever pixel array that uses residual stress polysilicon and metal film arms to …

Improving The Quality Of Low Bitrate Lpc Speech Codec Using Gamma-Chirp Filterbank, Amin Khajeh Djahromi

Electrical Engineering Theses

In this thesis, two methods for getting higher speech quality in low bit-rate LPC coder in comparison with the original LPC coder were presented. In order to improve the quality of the speech, the embedded method which can take the place of the traditional synthesis algorithm in LPC coders and the post-processing method that also can be used as the last stage in the LPC-coder based systems were proposed. In the embedded method, the result of MOS test of the synthesized speech increased by 0.8 and in the post-processing method the result of MOS test of the synthesized speech increased …

Study Of Si/Sio2 Interface Passivation And Sio2 Reliability On Deuterium Implanted Silicon, Tias Kundu

Dissertations

One of the major defects that contribute to the interface states in the silicon band gap is the dangling bond, which degrades performance of MOS devices. Passivation of these bonds with hydrogen had been found to diminish their effect but the improvement degrades the operation due to hot electron effect. Passivation with deuterium annealing has proven to improve the lifetime of the metal oxide semiconductor devices but this technique is not very effective for a multi-level metal-dielectric structure. This work investigates and optimizes incorporation of deuterium by ion implantation into the silicon substrate before the growth of 6.5 nm thin …

Variable Permittivity Dielectric Material Loaded Stepped-Horn Antenna, Ozgur Ozdemir

Dissertations

Stepped-horn antenna loaded with dielectric material of variable permittivity is proposed to improve radiation characteristics and/or to increase the electrical dimensions of the radiating structure compared to unloaded empty one. A hybrid numerical technique is used to analyze such an antenna. The tapered section of the horn antenna is modeled by multi-stepped waveguide structures filled with variable dielectric constant material. Generalized scattering matrix representation of the tapered section of the horn antenna is obtained using mode matching technique. The radiating aperture problem is solved by the method of moments, under the assumption that the horn is terminated by an infinite …

Opportunistic Transmission Scheduling For Next Generation Wireless Communication Systems With Multimedia Services, Chengzhou Li

Dissertations

The explosive growth of the Internet and the continued dramatic increase for all wireless services are fueling the demand for increased capacity, data rates, and support of different quality of service (QoS) requirements for different classes of services. Since in the current and future wireless communication infrastructures, the performances of the various services are strongly correlated, as the resources are shared among them, dynamic resource allocation methods should be employed. With the demand for high data rate and support of multiple QoS, the transmission scheduling plays a key role in the efficient resource allocation process in wireless systems. The fundamental …

Energy Efficient Organization And Modeling Of Wireless Sensor Networks, Jin Zhu

Dissertations

With their focus on applications requiring tight coupling with the physical world, as opposed to the personal communication focus of conventional wireless networks, wireless sensor networks pose significantly different design, implementation and deployment challenges. Wireless sensor networks can be used for environmental parameter monitoring, boundary surveillance, target detection and classification, and the facilitation of the decision making process. Multiple sensors provide better monitoring capabilities about parameters that present both spatial and temporal variances, and can deliver valuable inferences about the physical world to the end user.

In this dissertation, the problem of the energy efficient organization and modeling of dynamic …

Multicodes For Improved Range Resolution In Radar, Rhiya Vitto

Theses

Third generation (3G) wireless systems are required to support a variety of communication services like voice, image, motion picture transmission, etc, each of which requires different transmission rates. Multi-code modulation has been introduced therefore as a means of supporting multi-rate services and operating in multi-cell environments [8, 9, 10]. This multi-rate multi-function capability may be used in Radar related applications, too. For example, a single transmitted waveform consisting of two orthogonal codes can be used to simultaneously track a target and obtain high range resolution. Tracking requires low bandwidth and high resolution needs a high bandwidth signal. Orthogonal codes like …

Enhancing End-To-End Quality Of Service Provisioning In Wireless Ad Hoc Networks Using Service Vectors, Didem Gozupek

Theses

A cross-layer architecture that achieves significant power savings, while enhancing the end-to-end QoS provisioning and granularity in wireless ad hoc networks is proposed in this thesis. Recently, a new concept called service vector has been introduced, which enables an end host to choose different service classes along its data path. This scheme enhances the user benefits from the network services and network resource utilization, while maintaining the simplicity and scalability of the current Differentiated Services (DiffServ) network architecture. This thesis explores the application of this concept on wireless ad hoc networks and provides a cross-layer architecture based on the combination …

Deposition Of Tantalum Thin Films By Rf Sputtering With Substrate Bias, Savita Raina

Theses

The effects of energetic ion bombardment on the crystallographic structure of RF sputtered tantalum thin films on different substrates, particularly aluminum and silicon, have been studied. The effect of substrate biasing on ion current and film thickness has been investigated. The study included comparison between substrate ion current of DC sputtering and RF sputtering and also was aimed at finding the process parameters, which could influence the crystallographic phase of Ta film. The characterization of Ta films is carried by RBS and x-ray diffraction techniques.

A magnetron sputtering system with a matching network between the source and the RF generator …

Automated Liquid Dispensing Pin For Dna Microarray Applications, Suganya Parthasarathy

Theses

This thesis describes the research and development of a new liquid dispensing/aspiring system that is capable of producing micro sized spots/droplets for molecular biology research and analysis. In particular, the application is focused on DNA microarray fabrication with the goals of smaller spot size, higher yield, more efficient usage of biological materials, and capability to handle high viscosity liquids. The new system is based on active sensing and control and it is part of a fully integrated robotic microarray system for genomic and proteomic applications. The prototype system handles water as well as thick liquids such as 100% glycerol and …

Low-Voltage Analog Circuit Design Using The Adaptively Biased Body-Driven Circuit Technique, Stephen Christopher Terry

Doctoral Dissertations

The scaling of MOSFET dimensions and power supply voltage, in conjunction with an increase in system- and circuit-level performance requirements, are the most important factors driving the development of new technologies and design techniques for analog and mixed-signal integrated circuits. Though scaling has been a fact of life for analog circuit designers for many years, the approaching 1-V and sub-1-V power supplies, combined with applications that have increasingly divergent technology requirements, means that the analog and mixed-signal IC designs of the future will probably look quite different from those of the past. Foremost among the challenges that analog designers will …

Design Of A Reconfigurable State Transition Algorithm For Fuzzy Automata, Paolo A. Tamayo

Masters Theses

An Ontological Controller, a type of supervisory controller used for complex industrial systems, is usually characterized by a large global state set. Monitoring the global state set of these systems is impractical when the desired goal path is chosen since the decision on the next state depends only on a small section of the total state space. The approach is to operate only in a small moving window of the large state transition path. The Hybrid Fuzzy-Boolean Finite State Machine (HFB-FSM) is part of the solution to implement this scheme. The HFB-FSM models the state graph along with plant data …

Design And Analysis Of New Concept Interior Permanent Magnet Synchronous Motor By 3d Finite Element Analysis, Seongtaek Lee

Masters Theses

Throughout the years Hybrid Electric Vehicles (HEV) require an electric motor which has high power density and wide constant power operating region as well as low manufacturing cost. For these purposes, a new concept permanent magnet motor is designed and analyzed with the basic theories about Interior Permanent Magnet Synchronous Motor (IPMSM).

This new motor has DC excitation coils and flux paths, which can increase the output torque and be controlled for field weakening operating. The analysis has been conducted by three-dimensional Finite Element Analysis. The results show the possibility of the new motor for HEV applications. The new motor …

Civilian Target Recognition Using Hierarchical Fusion, Balasubramanian Lakshminarayanan

Masters Theses

The growth of computer vision technology has been marked by attempts to imitate human behavior to impart robustness and confidence to the decision making process of automated systems. Examples of disciplines in computer vision that have been targets of such efforts are Automatic Target Recognition (ATR) and fusion. ATR is the process of aided or unaided target detection and recognition using data from different sensors. Usually, it is synonymous with its military application of recognizing battlefield targets using imaging sensors. Fusion is the process of integrating information from different sources at the data or decision levels so as to provide …

Design And Development Of Epics Based Rf Conditioning System For The High Power Rf Components Of Charged Particle Accelerators, S.M. Shajedul Hasan

Masters Theses

Charged particle accelerators use various vacuum windows on their accelerating RF cavities to pass very high RF power through for the acceleration of particles. The accelerating cavities and the windows should be cleaned, baked and fully RF conditioned to eliminate poor vacuum caused by outgassing and other contamination. The linear accelerator (Linac) in the Spallation Neutron Source (SNS) contains various accelerating cavity structures and RF conditioning of their high power vacuum windows is necessary for present work as well as future upgrade and development. An example is the coaxial fundamental power coupler (FPC) with an annular alumina ceramic window for …