Engineering Commons^™

Fpga Design Of A Hardware Efficient Pipelined Fft Processor, Ryan T. Bone

Browse all Theses and Dissertations

Digital receivers involve fast Fourier transform (FFT) computations that require a large amount of arithmetic operations. The implementation of a FFT processor is one of the most challenging parts in the realization of a wideband receiver and its hardware complexity is very high. Hence, kernel function FFT processors have been proposed to meet real-time processing requirements and to reduce hardware complexity by rounding the kernel function to predetermined kernel points so as to eliminate the multipliers and use only shifters and adders or subtractors. Because of the nonlinear nature of this approximation by the rounding errors, spurious responses are generated …

Histogram-Based Template Matching Object Detection In Images With Varying Brightness And Contrast, Christina Da-Wann Schrider

Browse all Theses and Dissertations

Our challenge was to develop a semi-automatic target detection algorithm to aid human operators in locating potential targets within images. In contrast to currently available methods, our approach is relatively insensitive to image brightness, image contrast and object orientation. Working on overlapping image blocks, we used a sliding difference method of histogram matching. Incrementally sliding the histograms of the known object template and the image region of interest (ROI) together, the sum of absolute histogram differences was calculated. The minimum of the resultant array was stored in the corresponding spatial position of a response surface matrix. Local minima of the …

Model And Solution Approaches For The Equipment Scheduling Under Disruption Problems In Usps Mail Processing And Distribution Centers, Arvindkumar Ravi Chakravarthy

Browse all Theses and Dissertations

This research addresses the equipment scheduling problem under disruptions in United States Postal Service mail processing and distribution centers. These facilities contain a large variety of equipment and employ a non-homogeneous workforce that work on shifts of various lengths and start times. The scheduling of equipment (the determination of the configuration and usage of equipment to match mail arrivals) and the scheduling of workforce (the determination of the optimal size and composition of the workforce, their days off / lunch assignments, and overtime usage) to meet processing service commitment with a constantly changing demand are some of the most challenging …

A Stochastic Production Planning Model Under Uncertain Demand, Meenakshi Prajapati

Browse all Theses and Dissertations

Production planning plays a vital role in the management of manufacturingfacilities. The problem is to determine the production loading plan consisting of the quantity of production and the workforce level - to fulfill a future demand. Although the deterministic version of the problem has been widely studied in the literature, the stochastic production planning problem has not. The application of production planning models could be limited if the stochastic nature of the problem, for example, uncertainty in future demand, is not addressed. This study addresses such a stochastic production planning problem under uncertain demand and its application in an enclosure …

Biomechanical Evaluation Of Locked And Non-Locked Constructs Under Axial And Torsion Loading, Vinit A. Patel

Browse all Theses and Dissertations

Locking compression plates are proven to be safe for use in open reduction and internal fixation (ORIF). The ORIF is a procedure performed to treat fractures. It has various combination of holes, the system provides more options for clinicians to use either locking screw or non-locking screws. This thesis investigates and determines the best construct with special locking and non-locking screws under both axial and torsion loading. Twenty femur constructs were assembled with 2 cm osteotomy gap between femur shaft and condyle, bridged with 4.5 mm - 10 holes condyle plates. Femurs were divided in to 4 groups according to …

Dynamic Characterization Of A Pneumatic Muscle Actuator And Its Application To A Resistive Training Device, Jennifer L. Serres

Browse all Theses and Dissertations

Research described in this dissertation expands the use of a biomechanical phenomenological model to a commercially available pneumatic muscle actuator (PMA). Due to the nonlinearities of the device, achieving accurate control is challenging. Experiments have been conducted that define boundaries of operation where linear approximations can be used to describe the dynamics of the PMA. Empirical data presented in this dissertation show that nonlinearities exist more prevalently at higher loads (on average >70% contractile force value). When the PMA is under high loads, low displacement occurs. Therefore, these regions are of less interest to design engineers. Once conditions of nonlinearities …

A Novel Accurate Approximation Method Of Lognormal Sum Random Variables, Xue Li

Browse all Theses and Dissertations

Sums of lognormal random variables occur in many problems in wireless communications due to large-scale signal shadowing from multiple transmitters. With the emerging of cognitive radio technology, accurate analysis of interferences from multiple primary users and multiple secondary users is required. Such interferences are well modeled by the lognormal sum distribution. The lognormal sum distribution is known to have no close-form and is difficult to compute numerically. Several approximations to the lognormal sum distribution have been proposed and employed in literature. However, these approximation methods are not without their drawbacks. Some widely used approximation methods are not accurate at the …

Motion-Control System Of Bench-Top Ct Scanner, Tarpit Kaushikbhai Patel

Browse all Theses and Dissertations

Computed Tomography (CT) imaging has found applications in many areas such as diagnostic visualization, quantitative estimation, and therapeutic verification. In this wide range of applications, a CT scanner that can provide the data collection schemes of both second- and third-generation data-collection geometries will be an asset for laboratory research. In this thesis project, we developed a mechanical design and constructed a dual-generation CT scanner that provides flexibility in accommodating a wide range of object sizes with minimum scan time. Using 3-D graphical design software, models of the current second-generation CT scanner and possible solutions for modification were simulated. Based on …

Finite Element Optimization Of Hip Implant Geometrical Parameters To Determine Safe Zones And Resist Dislocation, Himanshu K. Bhatt

Browse all Theses and Dissertations

A computational study was performed using finite element analysis (FEA) of three dimensional solid hip implant models. Twelve different hip implant models were designed to investigate the performance of geometrical parameters affecting hip stability. The parameters examined were head diameter, neck diameter, head-to-neck ratio, neck angle and acetabular liner thickness. Component orientations included cup anatomical inclination and cup anteversion, which should be accounted for during total hip implant design as well as in the practice of arthroplasties. A static analysis was performed for all 12 hip designs using stainless steel 316L. von Mises stress, contact stress, contact penetration, and sliding …

Two Dimensional Localization Of Passive Uhf Rfid Tags, Bhavik Contractor

Browse all Theses and Dissertations

The advent of GPS has redefined the need of a positioning system in today*#8217;s ubiquitous computing world. While GPS works satisfactorily and is quite a norm in an outdoor environment, it fails to work indoors due to the inherent complexity of an indoor environment. There is an ever increasing need to develop an indoor positioning system and a lot of research has been done to solve the problem of indoor localization. These solutions differ on the basis of cost, dependency on environment, line of sight requirements and so on.

Passive RFID (Radio Frequency Identification) tags pose an interesting solution to …

A Low-Cost Acoustic Array For Detecting And Tracking Multiple Acoustic Targets, Ellen E. Case

Browse all Theses and Dissertations

A wide variety of real-world targets emit distinct acoustic signatures that not only distinguish them from one another but also provide spectral separation from background clutter. While acoustic signatures are distinct, they can also be highly variable, even for an individual target, making detection and tracking a challenging problem. This thesis presents a low-cost acoustic array using commercial off-the shelf (COTS) hardware to detect and track multiple small, moving, acoustic targets. It implements a cross-correlation method for calibration, delay-and-sum beamforming, CA-CFAR detection, a discrete Kalman filter for tracking, and nearest neighbor data association. In addition, the array is designed to …

An Algorithm For The Detection Of Handguns In Terahertz Images, Andrew J. Lingg

Browse all Theses and Dissertations

This paper presents an algorithm for detecting handguns in terahertz images. Terahertz radiation is capable of penetrating certain materials which are opaque atoptical wavelengths, such as clothing, without the harmful effects of ionizing radiation. The approach taken is to segment objects of interest and classify them based on shape. We use a modified version of an active contour algorithm found in the open literature. Modifications include: a pre-processing step that includes clutter filtering and seeding of an initial contour; and a post-processing step that removes clutter pixels from the segmentation. The features used for classification are moment-based and Fourier shape …

Automated Analysis Of Metacarpal Cortical Thickness In Serial Hand Radiographs, Aarti Raheja

Browse all Theses and Dissertations

To understand the roles of various genes that influence skeletal bone accumulation and loss, accurate measurement of bone mineralization is needed. However, it is a challenging task to accurately assess bone growth over a person's lifetime. Traditionally, manual analysis of hand radiographs has been used to quantify bone growth, but these measurements are tedious and may be impractical for a large-scale growth study. The aim of this project was to develop a tool to automate the measurement of metacarpal cortical bone thickness in standard hand-wrist radiographs of humans aged 3 months to 70+ years that would be more accurate, precise …

Implementation Of Null Conventional Logic In Cots Fpga's, Mohamad Rajgara

Browse all Theses and Dissertations

The digital world has been dominated by the growth of synchronous digital design techniques for last few decades. Traditional Boolean logic is symbolically incomplete since it has a separate control logic, time in the form of clock signal which be carefully integrated with the logic design, but with digital clock signal already in the GHz range, this integration is further complicated. One approach to address post GHz digital logic design is to use clockless or asynchronous digital design techniques. In the mid '90s Theaseus Logic Inc. proposed a method to design Asynchronous circuits using Null Convention Logic (NCL).This thesis introduces …

Multilingual Articulatory Features For Speech Recognition, Brian M. Ore

Browse all Theses and Dissertations

Articulatory features describe the way in which the speech organs are used when producing speech sounds. Research has shown that incorporating this information into speech recognizers can lead to an improvement in system performance. The majority of previous work, however, has been limited to detecting articulatory features in a single language. In this thesis, Gaussian Mixture Models (GMMs) and Multi-Layer Perceptrons (MLPs) were used to detect articulatory features in English, German, Spanish, and Japanese. The outputs of the detectors were used to form the feature set for a Hidden Markov Model (HMM)-based phoneme recognizer. The best overall detection and recognition …

An Analog Evolvable Hardware Device For Active Control, Saranyan A. Vigraham

Browse all Theses and Dissertations

The field of Evolvable Hardware (EH) has recently gained a lot of interest due to the novel methodology it offers for designing electrical circuits and machines. EH techniques involve configuring a reconfigurable hardware platform with the aid of learning engines such as evolutionary algorithms. The EH devices normally act as closed loop controllers with the capability of learning necessary control laws adaptively. Current EH practices have several shortcomings, which have restricted their use as reliable controllers. This dissertation will present an improved EH device based on behavioral reconfigurability that addresses the current open challenges in the field of analog Evolvable …

Analysis Of A Small-Signal Model Of A Pwm Dc-Dc Buck-Boost Converter In Ccm, Julie Joann Lee

Browse all Theses and Dissertations

The objective of this research is to analyze and simulate the pulse-width-modulated (PWM) dc-dc buck-boost converter and design a controller to gain stability for the buck-boost converter. The PWM dc-dc buck-boost converter reduces and/or increases dc voltage from one level to a another level in devices that need to, at different times or states, increase or decrease the output voltage.

In this thesis, equations for transfer funtions for a PWM dc-dc open-loop buck-boost converter operating in continuous-conduction-mode (CCM) are derived. For the pre-chosen design, the open-loop characterics and the step responses are studied. The converter is simulated in PSpice to …

High-Speed Low-Voltage Cmos Flash Analog-To-Digital Converter For Wideband Communication System-On-A-Chip, Mingzhen Wang

Browse all Theses and Dissertations

With higher-level integration driven by increasingly complex digital systems and downscaling CMOS processes available, system-on-a-chip (SoC) is an emerging technology of low power, high cost effectiveness and high reliability and is exceedingly attractive for applications in high-speed data conversion wireless and wideband communication systems. This research presents a novel ADC comparator design methodology; the speed and performance of which is not restricted by the supply voltage reduction and device linearity deterioration in scaling-down CMOS processes. By developing a dynamic offset suppression technique and a circuit optimization method, the comparator can achieve a 3 dB frequency of 2 GHz in 130 …

On-Chip Signal Generation And Response Waveform Extraction For Analog Built-In-Self-Test, Brian Poling

Browse all Theses and Dissertations

Built-In Self-Test (BIST) is a method of designing and creating an electronic chip or an electronic system that can self test for correct functionality and ensure no manufacturing defects. The reason for analog BIST is the testing of analog parts of analog and mixed-signal ICs is a costly process that traditionally requires the use of expensive high-end automatic test equipment. Due to the nature of the testing and length of the testing process, an efficient analog BIST scheme is in high demand for the ever increasing complexity of analog and mixed-signal circuits. This thesis presents a BIST scheme for generation …

Modeling And Simulation Of A Microturbine Generator To Be Coupled With A Molten Carbonate Fuel Cell For Distributed Generation, Karleine M. Justice

Browse all Theses and Dissertations

Distributed generation is desired when the individual energy requirements ranging from 25-75 kW of office buildings, restaurants, hospitals and apartments can not be met by the current electric utility grid. Microturbine generators as stand alone power generation systems have been designed to meet these requirements. For power requirements up to 50 MW, hybrid fuel cell systems offer higher efficiency and lower levels of pollutant emissions with more advanced fuel energy savings than non-hybrid systems. The objective of this project is to develop a simulation of a microturbine generator as a stand alone power generation system to validate a microturbine generator …

On Optimal Survivability Design In Wdm Optical Networks Under Scheduled Traffic Models, Tianjian Li

Browse all Theses and Dissertations

Wavelength division multiplexing (WDM) optical networks are widely viewed as the most appropriate choice for future Internet backbone with the potential to fulfill the ever-growing demands for bandwidth. WDM divides the enormous bandwidth of an optical fiber into many non-overlapping wavelength channels, each of which may operate at the rate of 10 Gigabit per second or higher. A failure in a network such as a cable cut may result in a tremendous loss of data. Therefore, survivability is a very important issue in WDM optical networks. The objective of this dissertation is to address the survivability provisioning problem in WDM …

An Initial Methodology For The Definition And Implementation Of Unmanned Aerial Vehicle Agent Behaviors, William Eric Marsh

Browse all Theses and Dissertations

In many current agent-based modeling systems, it is difficult for a domain-expert user to define and implement agent behaviors without possessing extensive programming knowledge. MUAVES is an existing simulation environment that serves as a research testbed for examining command and control issues with unmanned aerial vehicle (UAV) systems containing many vehicle agents. In its previous form, defining agent behaviors required knowledge of the C# programming language that some MUAVES users did not have. This thesis presents a new methodology for the definition and implementation of UAV agent behaviors in MUAVES. The new methodology is based on diagramming an agent's controller …

Loss Of Hdmx Leads To Alterations In Gene Expression And Inhibition Of Cell Growth In Tumor Cells With Wild-Type P53, Katherine Ann Heminger

Browse all Theses and Dissertations

Mutations in the p53 tumor suppressor gene are among the most prevalent molecular abnormalities in human cancer. While half of all human tumors possess p53 mutations, inactivation of wild-type p53 can also occur through a variety of mechanisms that do not involve p53 gene mutation or deletion. This dissertation focuses on human tumor cell lines harboring wild-type p53 protein and elevated levels of HdmX and/or Hdm2, two critical negative regulators of p53 function. My hypothesis is that loss of HdmX in tumor cells with wild-type p53 and over-expressed HdmX, will activate p53 and induce p53 target genes leading to growth …

Implementation For A Coherent Keyword-Based Xml Query Language, Venkatakalyan Potturi

Browse all Theses and Dissertations

Due to the increasing pervasiveness of data sets using the XML data format, numerous query languages have been proposed that exploit the structure inherent in XML. Many such query languages, supported by specialized XML search engines, are complex and not suitable for naive users. A simple keyword based query language is described which not only exploits the structure of XML documents to extract relevant fragments, but can also fall back on retrieval through plain text search. This thesis focuses on developing a prototype implementation for a Coherent Keyword Based XML Query Language. It analyzes the typical challenges posed by the …

An Evolutionary Programming Algorithm For Automatic Chromatogram Alignment, Bonnie Jo Schwartz

Browse all Theses and Dissertations

Scientists use liquid chromatography/mass spectrometry (LC/MS) instruments to measure metabolic responses to external stimuli. The data from these instruments can be distorted due to changes in the testing environment. Automating the removal of distortions is crucial in processing the data. The purpose of this thesis is to develop an algorithm that will automate the process.

The data produced by the LC/MS instrument were treated as images and image registration techniques were applied. A polynomial transformation function was assumed. An evolutionary programming algorithm was used to determine the coefficients of the polynomial. The data was manipulated to determine the best registration …

Designing Computer Agents With Personality To Improve Human-Machine Collaboration In Complex Systems, Sasanka V. Prabhala

Browse all Theses and Dissertations

The dynamic nature of complex systems and the overwhelming amount of data that must be handled by human operators requires the development of smart systems that augment human capabilities. For these systems human-agent collaboration is part of the system dynamic. Unfortunately the computer agent is not typically perceived by the human operator as a collaborative team member. This research addressed the key question of how to develop and evaluate computer agents with personality to enhance human-machine collaboration. To move towards this goal three research objectives were established: (1) develop agents with personality, (2) validate that humans perceive these agents as …

A Gnu Radio Based Software-Defined Radar, Lee K. Patton

Browse all Theses and Dissertations

GNU Radio is an open source software-defined radio project, and the Universal Software Radio Peripheral (USRP) is hardware designed specifically for use with GNU Radio. Together, these two technologies have been used to implement very sophisticated, yet low cost, software-defined radios. Since software-defined radio and software-defined radar are really one in the same technologies, it stands to reason that GNU Radio and the USRP could be utilized to form a low cost radar sensor. In this thesis, we discuss the design of a prototype software-defined radar, built using the open source GNU Radio and open specification USRP projects. The prototype …

Role-Based Access Control For The Open Grid Services Architecture - Data Access And Integration (Ogsa-Dai), Anil L. Pereira

Browse all Theses and Dissertations

Grid has emerged recently as an integration infrastructure for the sharing and coordinated use of diverse resources in dynamic, distributed virtual organizations (VOs). A Data Grid is an architecture for the access, exchange, and sharing of data in the Grid environment. In this dissertation, role-based access control (RBAC) systems for heterogeneous data resources in Data Grid systems are proposed. The Open Grid Services Architecture - Data Access and Integration (OGSA-DAI) is a widely used framework for the integration of heterogeneous data resources in Grid systems.

However, in the OGSA-DAI system, access control causes substantial administration overhead for resource providers in …

Optimal Eeg Channels And Rhythm Selection For Task Classification, Vikramvarun Kannan Adikarapatti

Browse all Theses and Dissertations

The Primary Objective of this research is to implement an automatic method for selecting the most optimal EEG channels for task classification purposes. The secondary objective of this research is to choose the most optimal EEG rhythm from which the optimal EEG channels would be selected automatically. The automatic selection of the optimal channels is enabled by implementing the Common Spatial Patterns algorithm (CSP). Common spatial analysis is performed on the data recorded. By choosing the channels with high spatial pattern values the optimal channels are chosen. The optimal frequency bands are chosen by splitting the data from a single …

Processing Nano Graphene Plates (Ngps) And Ngp Nanocomposite, Yena Li

Browse all Theses and Dissertations

In recent years numerous efforts worldwide are addressing all aspects of the rapid developing field of nanocomposites. However, the most important fillers-- carbon nanotube and carbon nanofiber - are expensive. In this study, our efforts are aimed at bridging the gap in cost and properties by providing a systematic study of alternative nano materials -- nano graphene plate (NGP) and related composites. We fabricated nano graphene plates through the detailed study of raw materials, chemical treatment methods and nano particle dispersion methods. A series of thermal expansion experiments were conducted to investigate the best condition to expand acid treated graphite …