Engineering Commons^™

A Semantic Situation Awareness Framework For Indoor Cyber-Physical Systems, Pratikkumar Desai

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Recently, the domain of cyber-physical systems (CPSs) has emerged as a successor to the traditional embedded systems and the wireless sensor networks. The relatively new cyber-physical domain offers tight integration of control, communication and computation components to develop advanced web based application in various heterogeneous domains such as health care, disaster management, automation and environment monitoring. The applications of indoor CPSs include remote patient monitoring, smart home, etc. with focus on situation awareness via event identification from context information. The principal challenges associated with the development of situation awareness applications include uncertainty in contextual data, incomplete domain knowledge, interoperability between …

New Insights Into The Spinal Recurrent Inhibitory Pathway Normally And After Motoneuron Regeneration, Ahmed Zayed Obeidat

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Despite more than seven decades of intensive research, uncertainty is the hallmark of spinal recurrent inhibition. The simplest possible structure that is formed between the a-motoneuron and its inhibitory interneurons has been the subject of long lasting scientific debate. To date, there is no consensus on the functional significance of this circuit. Even the simplest assumption of a negative feedback loop does not hold true. The current work used the technique of in vivo intracellular recording from the adult rat a-motoneurons to study the normal function and the plasticity after nerve injury and regeneration of this simple, yet intricate spinal …

Stability Of A Fuzzy Logic Based Piecewise Linear Hybrid System, Aaron W. Seyfried

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Complex cyber-physical systems are difficult to model and control. However, humans are capable of accomplishing these tasks by constantly adapting and redefining the rules to control these complex systems. Fuzzy logic provides a means of encoding human inference into a control methodology. However, the fuzzy logic controllers are nonlinear and their stability is difficult to verify. Therefore, the widespread usefulness of fuzzy logic controllers is limited. It has been proven that fuzzy logic controllers can be implemented as piecewise linear switched controllers. It has also been shown that the piecewise linear system can be implemented as a hybrid system. Piecewise …

Integrity Monitoring For Multiple Errors In Vision Navigation Systems, Nicholas Allen Baine

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In aviation applications, navigation integrity is paramount. Integrity of GPS systems is well established with set standards. Vision-based navigation systems have been found to be an adequate substitute for GPS when it is unavailable but are unlikely to be utilized until there is a measure for system integrity. Work has been done to detect the effect of a single measurement pair being corrupted with a bias; however, the measurement geometry varies greatly with the environment. The environment could be sparse in visual features to track, or the environment could be rich with features. With more features, there is a greater …

Bull's-Eye Structure With A Sub-Wavelength Circular Aperture, Masoud Zarepoor

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This research focuses on improving the spatial resolution of terahertz (THz) imaging. Using a sub-wavelength aperture in a metal ground plane is the most common way to improve the spatial resolution, but a sub-wavelength aperture has low radiation transmission. To increase the radiation transmission of a sub-wavelength aperture, periodic circular grooves were put in the metal around the aperture. The sub-wavelength circular aperture and the periodic circular grooves around it are known as the bull's-eye structure. The bull's-eye structure shows high radiation transmission at its design frequency, and it also has sub-wavelength spatial resolution. This research designed the bull's-eye structure …

Structural-Acoustic Analysis And Optimization Of Embedded Exhaust-Washed Structures, Ryan N. Vogel

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The configurations for high speed, low observable aircraft expose many critical areas on the structure to extreme environments of intense acoustic pressure loadings. When combined with primary structural and thermal loads, this effect can cause high cycle fatigue to aircraft skins and embedded exhaust system components. In past aircraft design methods, these vibro-acoustic loads have often been neglected based on their relatively small size compared to other thermal and structural loads and the difficulty in capturing their dynamic and frequency dependent responses. This approach is insufficient for effective advanced designs of complex aerospace structures, such as internal ducted exhaust systems …

Mining Diversified Decision Trees Across Multiple Datasets To Capture Similarities And Alignable Differences, Qian Han

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This dissertation studies the problem of mining shared and alignable difference knowledge structures across multiple datasets/applications. Shared and alignable difference knowledge structures are important for identifying analogies between application domains and for forming new hypothesis in challenging research applications, and for assessing the degree and types of knowledge-level similarities and differences between application domains for use in learning transfer. Generally speaking, shared knowledge structures characterize underlying datasets and highlight conceptual-level structural similarities among the datasets. This dissertation studies the mining of shared decision trees, which are a special type of shared knowledge structures. We first consider building one shared decision …

Evening Methane Emission Pulses From A Boreal Wetland Correspond To Convective Mixing In Hollows, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Spatial and temporal heterogeneity of methane flux from boreal wetlands makes prediction and up-scaling challenging, both within and among wetland systems. Drivers of methane production and emissions are also highly variable, making empirical model development difficult and leading to uncertainty in methane emissions estimates from wetlands. Previous studies have examined this problem using point-scale (static chamber method) and ecosystem-scale (flux tower methods) measurements, but few studies have investigated whether different processes are observed at these scales. We analyzed methane emissions from a boreal fen, measured by both techniques, using data from the Boreal Ecosystem-Atmosphere Study. We sought to identify driving …

A Simple Model For The In-Plane Rotational Response Of A Disk Resonator In Liquid: Resonant Frequency, Quality Factor, And Optimal Geometry, Mohomad S. Sotoudegan, Stephen M. Heinrich, Fabien Josse, Nicholas J. Nigro, Isabelle Dufour, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.

Cantilever-Based Resonant Gas Sensors With Integrated Recesses For Localized Sensing Layer Deposition, C. Carron, P. Getz, J. J. Su, D. S. Gottfried, Fabien Josse, Stephen M. Heinrich

Civil and Environmental Engineering Faculty Research and Publications

This work presents mass-sensitive hammerhead resonators with integrated recesses as a gas-phase chemical microsensor platform. Recesses are etched into the head region of the resonator to locally deposit chemically sensitive polymers by ink-jet printing. This permits the sensing films to be confined to areas that (a) are most effective in detecting mass loading and (b) are not strained during the in-plane vibrations of the resonator. As a result of the second point, even 5-μm thick polymer coatings on resonators with a 9-12 μm silicon thickness barely affect the Q-factor in air. This translates into higher frequency stability and ultimately higher …

Timoshenko Beam Effects In Lateral-Mode Microcantilever-Based Sensors In Liquids (Proceedings), Joshua A. Schultz, Stephen M. Heinrich, Fabien Josse, Nicholas J. Nigro, Isabelle Dufour, Luke A. Beardslee, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.

Evaluation Of Bridge Maintenance Interventions Under Changing Deterioration Rates: A Markovian-Based Methodology, Dilum Fernando, Baolin Wan, Scott Walbridge

Civil and Environmental Engineering Faculty Research and Publications

Markovian transition probability matrices employing condition states are often used in bridge management systems to determine optimal intervention strategies. This approach assumes a constant deterioration matrix throughout the entire analysis period. However, in order to adequately model and evaluate intervention options such as fiber-reinforced polymer (FRP) strengthening, it is necessary to model the impact of the intervention on the deterioration rate. This paper presents a Markovian based approach to model interventions that impact deteriorating rates. A model employing this approach is proposed. A methodology to determine the optimal intervention strategy based on steady state probabilities is then presented. The proposed …

Introducing Adaptive Incremental Dynamic Analysis: A New Tool For Linking Ground Motion Selection And Structural Response Assessment, Ting Lin, Jack W. Baker

Civil and Environmental Engineering Faculty Research and Publications

Adaptive Incremental Dynamic Analysis (AIDA) is a novel ground motion selection scheme that adaptively changes the ground motion suites at different ground motion intensity levels to match hazard-consistent properties for structural response assessment. Incremental DynamicAnalysis (IDA), a current dynamic response history analysis practice in Performance-Based Earthquake Engineering (PBEE), uses the same suite of ground motions at all Intensity Measure (IM) levels to estimate structural response. Probabilistic Seismic Hazard Analysis (PSHA) deaggregation tells us, however, that the target distributions of important ground motion properties change as the IM levels change. To match hazard-consistent ground motion properties, ground motions can be re-selected …

Fault Location In Power Networks Using Synchronized Phasor Measurements, Cuong Nguyen

Theses and Dissertations

Faults in electric power systems can lead to cascading power outages which cause tremendous loss to the economy and affect people’s lives. Technical reports of recent blackout events in the United States pointed out the lack of situational awareness as one of the main causes of widespread outages. Time synchronized phasor measurement is recommended as a technology that can improve the monitoring of power system condition. By knowing exactly where a fault occurs, necessary actions can be taken in a timely manner and thus, damage caused by that fault can be limited. In this thesis, first, a method for precise …

Improved Limits And Portability Over Currently Employed Cadmium Monitoring Systems Through Preconcentration For Detection By Way Of Micro-/Nanofluidic Mechanisms, Paul F. Wach

Theses and Dissertations

Due to risk of environmental and biological accumulation of Cadmium (Cd), improved methods of early detection and monitoring must be explored as a preventative measure. Listed as one of the top three toxic heavy metals by the Environmental Protection Agency (EPA), the effects on ecological and human systems have well documented side-effects of physical mutation, reproductive sterility, kidney failure, liver disease, bone loss, and death. Found in batteries, metal plating, pigments, plastics, and cigarettes, Cd is also used as a neutron absorber in the nuclear industry as well as having 3 known radioactive isotopes. Urine Cd levels, which have been …

Growth Of Silver Nanoparticles On Transparent Substrates From Liquid Precursors: Improvements And Applications, Carlos Andrés Jarro Sanabria

Theses and Dissertations--Electrical and Computer Engineering

Interest in controlling the synthesis of silver nanoparticles in colloidal solutions has increased during the last two decades. There is also growing interest in forming layers of silver nanoparticles on substrates, particularly for surface-enhanced Raman spectroscopy applications. However, methods to grow silver nanoparticles directly on substrates have not been studied extensively, and there are few techniques for controlling the size, shape, density, and location of the particles. This work presents a simple and reliable method to photodeposit silver nanoparticles onto transparent substrates. The size, shape and deposition density of the nanoparticles are influenced by the precursor solution, light intensity, and …

Fpga To Power System Theorization For A Fault Location And Specification Algorithm, Christina Yeoman

Theses and Dissertations--Electrical and Computer Engineering

Fault detection and location algorithms have allowed for the power industry to alter the power grid from the traditional model to becoming a smart grid. This thesis implements an already established algorithm for detecting faults, as well as an impedance-based algorithm for detecting where on the line the fault has occurred and develops a smart algorithm for future HDL conversion using Simulink. Using the algorithms, the ways in which this implementation can be used to create a smarter grid are the fundamental basis for this research. Simulink was used to create a two-bus power system, create environment variables, and then …

Active Optimal Control Strategies For Increasing The Efficiency Of Photovoltaic Cells, Sharif Aljoaba

Theses and Dissertations--Electrical and Computer Engineering

Energy consumption has increased drastically during the last century. Currently, the worldwide energy consumption is about 17.4 TW and is predicted to reach 25 TW by 2035. Solar energy has emerged as one of the potential renewable energy sources. Since its first physical recognition in 1887 by Adams and Day till nowadays, research in solar energy is continuously developing. This has lead to many achievements and milestones that introduced it as one of the most reliable and sustainable energy sources. Recently, the International Energy Agency declared that solar energy is predicted to be one of the major electricity production energy …

Fpga-Based Implementation Of Dual-Frequency Pattern Scheme For 3-D Shape Measurement, Brent Bondehagen

Theses and Dissertations--Electrical and Computer Engineering

Structured Light Illumination (SLI) is the process where spatially varied patterns are projected onto a 3-D surface and based on the distortion by the surface topology, phase information can be calculated and a 3D model constructed. Phase Measuring Profilometry (PMP) is a particular type of SLI that requires three or more patterns temporarily multiplexed. High speed PMP attempts to scan moving objects whose motion is small so as to have little impact on the 3-D model. Given that practically all machine vision cameras and high speed cameras employ a Field Programmable Gate Array (FPGA) interface directly to the image sensors, …

Multi-Mode Self-Referencing Surface Plasmon Resonance Sensors, Jing Guo

Theses and Dissertations--Electrical and Computer Engineering

Surface-plasmon-resonance (SPR) sensors are widely used in biological, chemical, medical, and environmental sensing. This dissertation describes the design and development of dual-mode, self-referencing SPR sensors supporting two surface-plasmon modes (long- and short-range) which can differentiate surface binding interactions from bulk index changes at a single sensing location. Dual-mode SPR sensors have been optimized for surface limit of detection (LOD). In a wavelength interrogated optical setup, both surface plasmons are simultaneously excited at the same location and incident angle but at different wavelengths. To improve the sensor performance, a new approach to dual-mode SPR sensing is presented that offers improved differentiation …

Providing A Persistent Space Plug-And-Play Avionics Network On The International Space Station, Zachary A. Jacobs

Theses and Dissertations--Electrical and Computer Engineering

The CubeLab is a new payload standard that greatly improves access to the International Space Station (ISS) for small, rapid turn-around microgravity experiments. CubeLabs are small (less than 16”x8”x4” and under 10kg) modular payloads that interface with the NanoRacks Platform aboard the ISS. CubeLabs receive power from the station and transfer data using the standard terrestrial plug-and-play Universal Serial Bus (USB). The Space Plug-and-play Avionics (SPA) architecture is a modular technology for spacecraft that provides an infrastructure for modular satellite components to reduce the time to orbit and development costs for satellites. This paper describes the development of a bus …

Target Tracking With Binary Sensor Networks, Mengmei Liu

Theses and Dissertations--Electrical and Computer Engineering

Binary Sensor Networks are widely used in target tracking and target parameter estimation. It is more computationally and financially efficient than surveillance camera systems. According to the sensing area, binary sensors are divided into disk shaped sensors and line segmented sensors. Different mathematical methods of target trajectory estimation and characterization are applied. In this thesis, we present a mathematical model of target tracking including parameter estimation (size, intrusion velocity, trajectory, etc.) with line segmented sensor networks. Software simulation and hardware experiments are built based on the model. And we further analyze how the quantization noise affects the results.

Microphone Array Optimization In Immersive Environments, Jingjing Yu

Theses and Dissertations--Electrical and Computer Engineering

The complex relationship between array gain patterns and microphone distributions limits the application of traditional optimization algorithms on irregular arrays, which show enhanced beamforming performance for human speech capture in immersive environments. This work analyzes the relationship between irregular microphone geometries and spatial filtering performance with statistical methods. Novel geometry descriptors are developed to capture the properties of irregular microphone distributions showing their impact on array performance. General guidelines and optimization methods for regular and irregular array design are proposed in immersive (near-field) environments to obtain superior beamforming ability for speech applications. Optimization times are greatly reduced through the objective …

A Comprehensive Hdl Model Of A Line Associative Register Based Architecture, Matthew A. Sparks

Theses and Dissertations--Electrical and Computer Engineering

Modern processor architectures suffer from an ever increasing gap between processor and memory performance. The current memory-register model attempts to hide this gap by a system of cache memory. Line Associative Registers(LARs) are proposed as a new system to avoid the memory gap by pre-fetching and associative updating of both instructions and data. This thesis presents a fully LAR-based architecture, targeting a previously developed instruction set architecture. This architecture features an execution pipeline supporting SWAR operations, and a memory system supporting the associative behavior of LARs and lazy writeback to memory.

Power-Efficient And Low-Latency Memory Access For Cmp Systems With Heterogeneous Scratchpad On-Chip Memory, Zhi Chen

Theses and Dissertations--Electrical and Computer Engineering

The gradually widening speed disparity of between CPU and memory has become an overwhelming bottleneck for the development of Chip Multiprocessor (CMP) systems. In addition, increasing penalties caused by frequent on-chip memory accesses have raised critical challenges in delivering high memory access performance with tight power and latency budgets. To overcome the daunting memory wall and energy wall issues, this thesis focuses on proposing a new heterogeneous scratchpad memory architecture which is configured from SRAM, MRAM, and Z-RAM. Based on this architecture, we propose two algorithms, a dynamic programming and a genetic algorithm, to perform data allocation to different memory …

Vision Based Real-Time Monitoring And Control Of Metal Transfer In Laser Enhanced Gas Metal, Yan Shao

Theses and Dissertations--Electrical and Computer Engineering

Laser enhanced gas metal arc welding (GMAW) is a novel welding process where a laser is applied to provide an auxiliary detaching force to help detach the droplet such that welds may be made in gas tungsten arc welding high quality at GMAW high speeds. The current needed to generate the electromagnetic (detaching) force is thus reduced. The reduction in the current helps reduce the impact on the weld pool and over-heat fumes/smokes. However, in the previous studies, a continuous laser is applied. Since the auxiliary is only needed each time the droplet needs to be detached and the detachment …

An Attitude Determination System With Mems Gyroscope Drift Compensation For Small Satellites, Maxwell Bezold

Theses and Dissertations--Electrical and Computer Engineering

This thesis presents the design of an attitude determination system for small satellites that automatically corrects for attitude drift. Existing attitude determination systems suffer from attitude drift due to the integration of noisy rate gyro sensors used to measure the change in attitude. This attitude drift leads to a gradual loss in attitude knowledge, as error between the estimated attitude and the actual attitude increases.

In this thesis a Kalman filter is used to complete sensor fusion which combines sensor observations with a projected attitude based on the dynamics of the satellite. The system proposed in this thesis also utilizes …

Visual Attitude Propagation For Small Satellites, Samir Ahmed Rawashdeh

Theses and Dissertations--Electrical and Computer Engineering

As electronics become smaller and more capable, it has become possible to conduct meaningful and sophisticated satellite missions in a small form factor. However, the capability of small satellites and the range of possible applications are limited by the capabilities of several technologies, including attitude determination and control systems. This dissertation evaluates the use of image-based visual attitude propagation as a compliment or alternative to other attitude determination technologies that are suitable for miniature satellites. The concept lies in using miniature cameras to track image features across frames and extracting the underlying rotation.

The problem of visual attitude propagation as …

Perceptual Ruler For Quantifying Speech Intelligibility In Cocktail Party Scenarios, Kirstin M. Brangers

Theses and Dissertations--Electrical and Computer Engineering

Systems designed to enhance intelligibility of speech in noise are difficult to evaluate quantitatively because intelligibility is subjective and often requires feedback from large populations for consistent evaluations. Attempts to quantify the evaluation have included related measures such as the Speech Intelligibility Index. These require separating speech and noise signals, which precludes its use on experimental recordings. This thesis develops a procedure using an Intelligibility Ruler (IR) for efficiently quantifying intelligibility. A calibrated Mean Opinion Score (MOS) method is also implemented in order to compare repeatability over a population of 24 subjective listeners. Results showed that subjects using the IR …

Parametric Average-Value Model Of Rectifiers In Brushless Excitation Systems, Thaer Qunais

Theses and Dissertations--Electrical and Computer Engineering

An average-value model of a rotating rectifier circuit in a brushless excitation system is set forth, where a detailed simulation is required to extract the essential averaged-model parameters using numerical averaging. In the proposed approach, a synchronous machine model with saturation and cross saturation and an arbitrary rotor network representation that uses a voltage-behind-reactance representation for the field winding of the main machine is proposed. This allows the field winding to be represented as branches in a circuit solver, permitting straightforward simulation with connected circuitry. Also a brushless exciter model is introduced to be compatible with the averaged-model, where the …