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Title: DEVELOPMENT OF AN EMBEDDED CONTROLLER FOR TWO QUADRANT OPERATION OF BLDC MOTORS IN AUTOMOTIVE APPLICATIONS
Creator: Liu, Yizhe
Date: 2011-07-06, 2011-07
Description: Due to growing concerns over the availability of non-renewable petroleum products and the increasing emphasis on protecting our environment...
Show moreDue to growing concerns over the availability of non-renewable petroleum products and the increasing emphasis on protecting our environment from green house gas emissions, plug-in hybrid electric vehicle and hybrid electric vehicles have been gaining increasing popularity over recent years. This has led to the design of advanced drive systems using different electric motors such as BLDC, PMSM, IM and SRM. An electric motor/generator requires controller that not only has a strong I/O control function, but also high speed signal processing ability for realizing real time control. Therefore, a DSP (Digital Signal Processors), which integrates flexible multiple PWM signal generator, high speed high precision ADC and encoder interface for motor speed and position feedback, is considered as one of the strongest controllers for electric motor control. Owing to a growing emphasis on identification, interference, and communication of security services of drive train in intelligent PHEVs and HEVs, a DSP can also be used to identify and isolate security issues in the integrity of the drive train in PHEVs and EVs. This thesis has two main contributions: a) it focuses on the development of an embedded controller using TMS320LF2812 DSP to realize two quadrant control of the BLDC; and b) it develops an automotive test bench to identify and investigate some potential security issues using the embedded controller’s eCAN communication function.
M.S. in Electrical Engineering, May 2011
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Title: STATISTICAL METHODS FOR LARGE-SCALE TRANSPORTATION NETWORK TRAFFIC VOLUME FORECASTING
Creator: Meng, Xiao
Date: 2012-11-27, 2012-12
Description: Forecasting is the procedure of making declarations about future events whose actual outcomes have not yet been observed. A lot of decisions...
Show moreForecasting is the procedure of making declarations about future events whose actual outcomes have not yet been observed. A lot of decisions are made based on predictions of future unknown events. Knowing the essence of forecasting, it is not hard to interpret what traffic volume forecasting is. Traffic volume forecasting is the process of estimating the number of vehicles that will be on a planned highway in the future. It plays important roles in different aspects of transportation and related field, such as highway level of service analysis, measure of effectiveness, highway improvement and expansion, geometric design and air quality analysis, etc. A good forecast is needed for decision making in future land use and transportation planning. City and county planners can provide useful information about land use planning and projected developments. County engineers may provide information about future county projects that may cause detours and changes in traffic patterns along a trunk highway. Highway designers need forecasted traffic volumes to ensure proper geometric designs. Since short term forecasting has been a hot topic on research, many statistical methods have been used, such as the mean, historical moving average, exponential smoothing, and autoregressive integrated moving average. Among them, Box Jenkins method (Autoregressive Integrated Moving Average) has been found as the best model on forecasting of time series data with seasonality and trend.
M.S. in Civil Engineering, December 2012
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Title: DYNAMIC SIMULATION AND LOAD MODELING FOR VOLTAGE RECOVERY STUDIES WITH THREE-PHASE AND SINGLE-PHASE INDUCTION MOTORS
Creator: Zhang, Jingpei
Date: 2017, 2017-05
Description: Transient stability topics have been popular in modern power systems and time domain simulation provides an efficient evaluation for...
Show moreTransient stability topics have been popular in modern power systems and time domain simulation provides an efficient evaluation for correlative studies. So far, we have been working on developing advanced time-domain simulator TS3ph, which implements simulation on electromechanical level but with three-phase completed network model to enable unbalanced modeling and simulation. In this paper, modeling and development work of TS3ph are being introduced. Positive-sequence equivalent and three-phase based models, including static var compensator, governor and three-phase induction motor models, are built and validated to evaluate their dynamic behaviors in transient state. Moreover, research work on single phase induction motor model development, including important motor behaviors such as motor stalling, is also introduced in this paper for voltage collapse and recovery study. This is indeed the first time to apply such model on electromechanical simulator as well.
M.S. in Electrical Engineering, May 2017
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Title: TEMPERATURE PROFILES THROUGH THE SHELL IN EGGS HEATED BY INFRARED ENERGY
Creator: Guo, Jingxin
Date: 2012-07-30, 2012-07
Description: Infrared heating is an effective method for surface pasteurization of shell eggs. As the external temperature reaches the inactivation...
Show moreInfrared heating is an effective method for surface pasteurization of shell eggs. As the external temperature reaches the inactivation temperature, internal temperatures could become great enough to denature albumen. However, the internal temperature of albumen at the shell cannot be measured directly. The purpose of this study is to use experimental data to understand the response of the albumen temperature at the shell to infrared radiation impinging at its outer surface. Fresh eggs were obtained from a local producer and refrigerated until needed. They were prepared for each experiment by overnight equilibration with ambient conditions. Each egg was placed on a metal stage over which an infrared lamp was positioned. The stage allowed a K-type thermocouple to be inserted through a small hole in the shell opposite of the shell area facing the lamp. The thermocouple was pushed into the egg such that the tip was against the inner surface of the shell just underneath the exposed area. The external temperature of this area was measured by an infrared pyrometer. Variables for these experiments were temperature of the IR lamp (277°C, 329°C, 391°C and 452°C), distance between shell egg and IR lamp (3.13 cm – 15.83 cm), and treatment time. All experiments share the same initial lag around 30s, suggested that the initial lag did not vary with changing of lamp-egg distances and lamp temperatures. After the initial lag, internal and external temperatures were found to increase at the same rate regardless of experimental parameters, indicating and equilibrium between the infrared energy impinging on the surface and its dissipation in the interior of the egg. The difference of temperature distributes between 10°C to 20°C. However, lowering lamp temperatures or increasing distances did not change this difference significantly. Moreover, the temperature gap sustains the same temperature after initial lag. The results showed that the internal temperature could be inferred via measuring external temperature. This is valuable in processing to maximize external surface temperature while protecting heat sensitive albumen. Future work will involve modeling the heating phenomenon to determine if knowing only the lamp temperature and distance is sufficient for predicting internal temperature.
M.S. in Food Processing Engineering, July 2012
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Title: BICYCLE CRASH ANALYSIS IN CHICAGO
Creator: Van Nortwick, Taylor Wade
Date: 2013, 2013-07
Description: The United States is making big plans for improvements in bicycle infrastructure. To best understand if the improvements will be successful in...
Show moreThe United States is making big plans for improvements in bicycle infrastructure. To best understand if the improvements will be successful in creating a safe network, a study was done to determine contributing factors in bicycle crashes. Bicycle and motor vehicle crash data from around Chicago between 2005 and 2011 was analyzed for significant factors in infrastructure, cyclist and motorist attributes. Temperature was used as a predictor of bicycle traffic due to the seasonality of bicycling in Chicago. It was found that more bicycles and vehicles result in higher crash rates. It was also found that on -street parallel parking, signalized, skewed and multiple legged intersections lead to higher crash rates.
M.S. in Civil Engineering, July 2013
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Title: MULTI-DIMENSIONAL BATCH SCHEDULING FRAMEWORK FOR HIGH-END SUPERCOMPUTERS
Creator: Zhou, Zhou
Date: 2016, 2016-05
Description: In the field of high performance computing (HPC), batch scheduling plays a critical role. They determine when and how to process the various...
Show moreIn the field of high performance computing (HPC), batch scheduling plays a critical role. They determine when and how to process the various jobs waiting for service. Conventional batch schedulers allocate user jobs solely based on their CPU footprints. However, for a given user job, it requires many different resources during its execution, such as power, network, I/O bandwidth, etc. Today’s job schedulers rarely take into account these resource requirements which sometimes turn out to be the Achilles’ heel of system-wide performance. In this research, we propose a multi-dimensional batch scheduling framework for high-end supercomputers. Our research aims to treat these common but often ignored resources (e.g., power, network, bandwidth) as schedulable resource and further transform each scheduling into a multi-objective optimization process. Our main contributions consist of a set of scheduling models and policies, aiming at addressing the issues in batch scheduling for large-scale production supercomputers. We evaluate our design by means of trace-based simulations using real workload and performance traces from production systems. Experimental results show our methods can effectively improve batch scheduling regarding user satisfaction, system performance and operating cost.
Ph.D. in Computer Science, May 2016
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Title: OPTIMAL SIGNAL TIMING DESIGN FOR URBAN STREET NETWORKS UNDER USER EQUILIBRIUM BASED TRAFFIC CONDITIONS
Creator: Liu, Yi
Date: 2015, 2015-05
Description: In the ever-growing travel demand, traffic congestion on freeways and expressways recurs more frequently at a higher number of locations and...
Show moreIn the ever-growing travel demand, traffic congestion on freeways and expressways recurs more frequently at a higher number of locations and for longer durations with added severity. This becomes especially true in large metropolitan areas. Particular to the urban areas, excessive crowdedness caused by inefficient traffic control also results in urban street networks operating in near or over-saturated conditions, leading to unpleasant travel experience due to long delays at intersections. As a consequence, the recurrent traffic congestion on roadway segments and vehicle delays at intersections inevitably compromise energy efficiency, traffic mobility improvement, safety enhancement, and environmental impacts mitigation. All too often, neither restraining travel demand nor expanding system capacity is desirable and practical. Conversely, effectively utilizing the capacity of the existing transportation system has been increasingly thought of as the solution to congestion relief. With respect to the urban street networks, developing effective means for urban intersection signal optimization becomes essential to reduce intersection delays. Conventional signal timing optimization methods use historical traffic data and assume that traffic flows will remains unchanged after the implementation of new signal timing plans. Traffic flows are assumed to be constant, but in fact, when signal timing plans change, travel times for some travel routes will alter, which requires drivers in the network to adjust their choice of travel routes to arrive at the destinations, and result in redistribution of traffic in the network. Therefore, the effects of interactions between signal timing plans and traffic flows need to be explicitly taken into consideration. This study introduces a new methodology that jointly considers signal timing optimization and traffic assignment in an overall analytical framework that contains model formulations under assumptions consistent with real world situations. Such a framework is well suited for applications in real world cases. Specifically, the overall optimization framework is formulated as a bilevel optimization problem. In the proposed basic model, at the upper level, a traffic signal timing optimization problem for urban network is introduced to minimize system total travel time by optimizing signal green splits. At the lower level, a static user equilibrium problem is formulated for networkwide traffic assignment. In the vehicle delay estimation, the time-dependent stochastic delay model in the 2010 Highway Capacity Manual (HCM 2010) is employed and formulated as Variational Inequality constraints, what allow the state-of-the-art MPEC solver, GAMS/NLPEC, to solve the problem for a local optimal effectively and efficiently. The bi-level optimization model is first tested using a small network (the test network) and a computational experiment using a subarea network in the Chicago central district is conducted to assess the practicality of the model formulation in real world applications. In order to import more reality to the basic model and also consider the potential system benefit that comes from different signal phasing design, an enhanced model is developed based on the basic model by employing integer and binary variables. Formulating the problem with binary variables allows for the selection of proper phasing design. Heuristic solution methods are proposed and tested using the test network.
Ph.D. in Civil Engineering, May 2015
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Title: DEVELOPMENT AND APPLICATION OF THE KIRIE WASTEWATER TREATMENT PLANT MODEL
Creator: Mendez, Thomas E.
Date: 2012-07-15, 2012-07
Description: The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is tasked with protecting the public’s water supply and improving the...
Show moreThe Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is tasked with protecting the public’s water supply and improving the quality of water in their service area’s watercourses. Principal in this mission are the seven wastewater treatment plants that are operated by MWRDGC. The greater Chicago area possesses a combined sewer system (CSS) that combines sanitary sewage and stormwater runoff. Because of this CSS, water reclamation plants are burdened with not only processing sewage and sanitary waste, but also stormwater runoff. As a result there can be a large variation in water quality and quantity. MWRDGC’s newest water reclamation plant is the James C. Kirie Water Reclamation Plant, which was completed in 1980. This plant operates as a nitrification plant with no separate distinct denitrification process. It is important to note that no clearly defined unit processes such as nitrification towers are utilized at the Kirie Water Reclamation Plant. Nitrification occurs primarily in the aeration basins and is currently sufficient to meet water quality standards. However, because of the current regulatory climate, stricter standards on effluent discharge are likely in the near future especially with respect to nutrients. Stricter standards on total nitrogen in effluent instead of the current ammonia limits are one such expected water quality change. As a result of this expectation, modeling modifications and processes at a treatment plant can be a key tool in adjusting to evolving standards. Because water reclamation plants vary greatly depending on their technology, influent and processes, computer modeling provides a convenient way to assess how the plant will react to dynamic changes in influent quality and still be able to meet static effluent standards. Although computer modeling has been applied to water reclamation plants for some time now, there are no clearly defined or accepted protocols for this modeling. Combined with the variation exhibited by various types of water reclamation plants, often modeling protocols must be custom created for individual plants or types of plants. What follows is a study and simulation of the Kirie Water Reclamation Plant. Simulation was used to examine wet weather events at the Kirie Water Reclamation Plant. Wet weather phenomena were explored in step-wise manner to determine the relative effects of different perturbations in influent water quality and quantity. The results show the various effects in effluent quality depending upon the variable or combination of variables deviated. Deviations in temperature and flow dominate all other variations simulated and result in the largest effect on effluent water quality. Deviations of 50% to both temperature and flow simultaneously yielded an increase in effluent BOD and NH3 at twice and six times the steady state values, respectively.
M.S. in Environmental Engineering, July 2012
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Title: DISRUPTION OF EPILEPTIC SEIZURES USING TARGETED MULTI-SITE ELECTRICAL STIMULATION
Creator: Sobayo, Tiwalade
Date: 2015, 2015-12
Description: Neuronal populations in the brain achieve levels of synchronous electrophysiological activity during both normal brain function and...
Show moreNeuronal populations in the brain achieve levels of synchronous electrophysiological activity during both normal brain function and pathological states such as epileptic seizures. Understanding how the dynamics of neuronal oscillators in the brain evolve from normal to diseased states is a critical component towards decoding such complex behaviors. In my studies, I assessed multi-site dynamics underlying seizure evolution in limbic epilepsy by analyzing oscillators in recordings of local field potentials from three brain structures (bilateral hippocampi and anteromedial thalamus) in a rat model of temporal lobe epilepsy extracted using the empirical mode decomposition (EMD) technique. The analysis revealed patterns of multi-site phase coherence during initiation and termination phases of seizures. The multi-site synchrony events as seizures naturally terminated were used to model electrical deep brain stimulation (DBS) protocols aimed at stopping ongoing epileptic seizures. The location and frequency of the natural termination synchrony varied between subjects but was stable in time within each animal. My studies reveal that DBS protocols were significantly more effective at rapidly stopping seizures when the frequency and location of multi-site stimulation reflected the endogenous synchrony dynamics observed in each subject. These results strongly suggest that tailoring DBS protocols to individual endogenous rhythms that may represent how brains naturally resolve epileptic seizures could play a critical role in vastly improving the overall efficacy of this important therapy.
Ph.D. in Biomedical Engineering, December 2015
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Title: SYSTEM-ON-CHIP ARCHITECTURES FOR SIGNAL PROCESSING AND COMMUNICAnONS
Creator: Niu, Sufeng
Date: 2012-04-30, 2012-05
Description: System-On-Chip (SOC) is one of the most popular Computer Aided Design (CAD) methodologies in electronic system design. In this research, SOC...
Show moreSystem-On-Chip (SOC) is one of the most popular Computer Aided Design (CAD) methodologies in electronic system design. In this research, SOC design is investigated in two different types of applications: i) low cost and power efficient applications; and ii) high performance computing applications. To explore low cost and power efficient design, a microcontroller based wireless medical system is investigated. Two wireless communication protocols for medical applications and patient monitoring are analyzed. In addition, the ZigBee stack developed by TI and a medical amplifier are discussed. For high performance SOC applications, implementations of several matrix operations are examined. An improved fixed-point hardware design of QR decomposition is introduced and optimized for Xilinx FPGAs. A Givens Rotation algorithm is implemented using a folded systolic array and the CORDIC algorithm. This approach is highly suitable for high-speed FPGAs or ASIC designs. It is found that the Xilinx XC5VLX110T FPGA is capable of running the QR decomposition at 246MHz.
M.S. in Electrical Engineering, May 2012
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Title: OPTIMAL BIDDING STRATEGY FOR HYDRO UNIT
Creator: Zhu, Renchen
Date: 2013-04-30, 2013-05
Description: The bidding price for the renewable energy is very different from some traditional energy, like gas, coal and so on, because when we produced...
Show moreThe bidding price for the renewable energy is very different from some traditional energy, like gas, coal and so on, because when we produced the renewable energy, the only cost is the generator unit cost, for example, wind power, water power and so on. People never need to pay the fuel price for the solar, water or wind. So here come one question how can we decide the energy price for these power. As we all know, the bidding price decided the profit for the generating company. Nowadays, more and more researches have been done in this field for every company want a good price to earn the highest profit. But for the renewable energy, they are different from the traditional energy which price is determined by the fuel price. So how to decide the bidding price of the renewable energy will be a good topic and question for us. To solve this problem, I will try to use an idea called minimum the imbalance in order to maximum the profit for those owners. This idea first has been applied in the wind unit. For my thesis, I will apply this idea to the hydro unit both with the storage and without storage. For each part, I will use some data to test. By these testing, the result will show this bidding strategy will be better.
M.S. in Electrical Engineering, May 2013
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Title: THERMODYNAMICS AND PHASE EQUILIBRIA OF HEUSLER ALLOYS
Creator: Chung, Yoonsung
Date: 2011-09, 2011-07
Description: Heusler compounds are of great interest for their properties such as shape memory, thermoelectric, ferromagnetic and spin polarization effects...
Show moreHeusler compounds are of great interest for their properties such as shape memory, thermoelectric, ferromagnetic and spin polarization effects that could lead to new mechanical and electronic devices. Currently, the study of Heusler alloys is focused on their electronic and magnetic properties, but the high temperature thermodynamic properties of these compounds have not been covered as much. A thorough knowledge of the thermodynamic properties and phase equilibria is required for developing this kind of alloys. This thesis is part of a systematic investigation of the thermodynamics and phase equilibria of ternary Heusler alloy systems. In this work, the high temperature reaction calorimeter was used to obtain the standard enthalpy of formation of compounds in the Ni2XSn (X = Ti, Zr, Hf, V and Nb) and Ni2TiX (X = Ga and In) ternary systems. It was confirmed the compound Ni2TaSn does not exist in the Heusler structure A Setaram Ligne 96 drop calorimeter was used to measure the heat content of Ni2TiSn as a function of temperature. Phase equilibria and crystal structures of Ni2TiSn, Ni2TiGa and Ni2TiIn were determined using XRD, SEM and EDS.
M.S. in Materials Science & Engineering, July 2011
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Title: ISOLATION OF MONOSPECIFIC ANTIBODY AGAINST SPLICED VARIANT OF DYSTROPHIN PROTEIN USING YEAST SURFACE DISPLAY TECHNIQUE
Creator: Saraswathi, Raj Prabu Vijayakumar
Date: 2011-05-04, 2011-05
Description: Dystrophin gene is the largest in the human genome with 79 exons covering greater than 0.1% of the total genome, located on the Xp21 locus of...
Show moreDystrophin gene is the largest in the human genome with 79 exons covering greater than 0.1% of the total genome, located on the Xp21 locus of the “X” chromosome resulting in a 427kDa protein, “Dystrophin”. Dystrophin is an important cytoskeletal protein which belongs to the β-Spectrin/α-actinin family of proteins. It comprises of an amino terminal domain, alpha helical coiled structure COOH domain, central rod region with 24 STRs and four proline rich hinge regions. It plays a vital role in localizing the Dystrophin glycoprotein complex (DGC) in the Sarcollema and is associated with the DGC in controlling the signaling events of certain proteins associated with DGC. The large size of the gene makes it more vulnerable to mutations resulting in partially functional or non-functional Dystrophin. The absence of Dystrophin results in disruption of sub sarcolemma-extracellular matrix linkage, loss of nitric oxide, progressive muscle weakening and muscle wasting leading to the death of patients typically before the end of their teenage. In certain cases alternatively spliced isoforms produce Dystrophin with reduced length yet stable and completely functionality. The main focus of this project was to select monospecific antibody against the more stable alternatively spliced variant D14 (15”16”) 17, which is functional and more stable compared to unspliced parent D14:17. The yeast surface display technique was used to effectively screen and select the yeast scFv clones containing the monospecific antibody against our target spliced variant D14 (15”16”) 17 protein and D2:3. The yeast scFv sub population was enriched by repeated MACS and FACS selection. Test colonies picked from the enriched scFv pool were confirmed via PCR and restriction digestion analysis. The scFv for the respective antigens were then sub cloned into pPnnl-9 secretion vector using YVH10 yeast cells via LiTRAFCO method. It was clear that by repeated MACS and FACS selection the scFv pool can be enriched and the yeast scFv clone sub population can be reduced to a significant level. The scFv sub cloned into Pnnl-9 secretion vector can be purified using affinity chromatography and the further affinity and avidity studies can be conducted.
M.S. in Biology, May 2011
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Title: L2E ESTIMATOR FOR THE CATEGORICAL MODEL WITH ELASTIC NET PENALTY
Creator: Wang, Yuan
Date: 2017, 2017-07
Description: The logistic regression model is an important generalized linear model for the categorical data. The maximum likelihood estimation is mostly...
Show moreThe logistic regression model is an important generalized linear model for the categorical data. The maximum likelihood estimation is mostly used in estimating the parameters of the logistic regression model. However, the maximum likelihood estimation is very sensitive to outliers which will cause the inaccuracies of the fitted parameters and model selection in high-dimensional regression. Chi and Scott (2014) demonstrated by simulation that minimizing the integrated square error or L2 estimation (L2E) is a robust method to fit 2-class categorical models. They also showed that the L2E estimation method can select the right model even in the presence of many outliers in high dimensional scenarios. In my thesis, I extended the L2E estimation method from 2-class to 3-class based on the MM algorithm by Chi and Scott (2014). Then I demonstrated the properties above for 2-class categorical models are also applicable to 3-class ones.
M.S. in Applied Mathematics, July 2017
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Title: PARAMETRIC IMAGE ESTIMATION IN ANALYZER-BASED PHASE CONTRAST IMAGING
Creator: Caudevilla, Oriol
Date: 2014, 2014-07
Description: Since the discovery of X-rays, by W.E. Roentgen in 1895, absorption-contrast imaging has been widely used in medical diagnostic, for example:...
Show moreSince the discovery of X-rays, by W.E. Roentgen in 1895, absorption-contrast imaging has been widely used in medical diagnostic, for example: mammography, chest X-ray, angiography etc. Over the last 25 years many researchers have shown that phase-contrast X-ray imaging is capable of obtaining a better contrast then classical absorption-contrast imaging. This is especially true in soft tissue imaging like mammography or at higher Xrays energies. During the past five years a significant effort has made in development of a tabletop analyzer-based phase-contrast system. In this system a perfect crystal is used to generate a quasi-monochromatic beam, which after interacting with an object is analyzed by a second perfect crystal called analyzer. The need of quasi-monochromatic beam and the low brilliance of conventional X-ray sources (CXS) has been the major limiting factor for tabletop systems. The work presents in this thesis aims to develop novel reconstruction methods for tabletop analyzer-based phase-contrast imaging (ABI) systems. The presented reconstruction methods goal is to minimize the impact of CXS low brilliance by utilizing phase-contrast image formation model and maximum or maximum-a-posteriori Poisson likelihood approach. Finally, a fast-convergent conjugate gradient optimization algorithm has been derived specifically for Poisson likelihood function maximization.
M.S. in Electrical Engineering, July 2014
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Title: NEUTRON PRODUCTION IN THE M2 MUON BEAM LINE AT CERN
Creator: Draeger, Emily
Date: 2014, 2014-05
Description: Spallation neutrons produced from cosmic ray muons are a major source of backgrounds in underground physics experiments. Experiments have been...
Show moreSpallation neutrons produced from cosmic ray muons are a major source of backgrounds in underground physics experiments. Experiments have been done to study spallation neutron production and yield, but our understanding of these processes is still limited. There are various interactions that can produce spallation neutrons. Most of these production mechanisms are fairly well understood; much of the uncertainty in our understanding of spallation neutrons lies in mechanisms such as virtual photon exchange and the assumptions used to calculate the photonuclear cross section. Even the experiments that have been carried out do not agree with each other or theoretical calculations. Spallation neutron production mechanisms are discussed, as well as a new experiment to study spallation neutrons. The impact of this study on current and future underground physics experiments is also explored.
PH.D in Physics, May 2014
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Title: Thermal conductivity
Creator: Bauer, W. Ernest, Jr
Date: 2009, 1917
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/thermalconductiv00baue
Thesis (B.S.)--Armour Institute of Technology; Includes folded leaves in back pocket

Title: POWER ANALYSIS AND CONTROL OPTIMIZATION OF A HIGH GAIN RESONANT DC-DC CONVERTER
Creator: Wu, Haowen
Date: 2017, 2017-05
Description: Applications of DC-DC converter require a high power, high efficiency performance, especially for automotive applications and renewable energy...
Show moreApplications of DC-DC converter require a high power, high efficiency performance, especially for automotive applications and renewable energy applications. A desired converter should have a fast response, stable output in different conditions. This thesis studies a novel high gain DC-DC resonant converter and its control. Based on the circuit analysis and operation evaluation, feed-forward and feedback control methods are proposed in order to achieve stability under variety of changes. Moreover, circuit topology is investigated in response to the efficiency improvement. Simulations in PSIM, PLECS and MATLAB Simulink have been carried out to validate the controller design and topology development. The simulation results are in consistence to the theoretical analysis. The overall high efficiency at nominal operating point is further increased.
M.S. in Electrical Engineering, May 2017
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Title: NOVEL FAULT DIAGNOSTIC TECHNIQUE AND UNIVERSAL SENSOR FOR PERMANENT MAGNET ELECTRIC MACHINES USING SEARCH COILS
Creator: Da, Yao
Date: 2012-04-23, 2012-05
Description: Over the past decade, permanent magnet synchronous machines (PMSMs) have gained significant popularity in industry, such as wind turbines and...
Show moreOver the past decade, permanent magnet synchronous machines (PMSMs) have gained significant popularity in industry, such as wind turbines and electric vehicles, owing to their high efficiency, high output power to volume ratio, and high torque to current ratio. In these mission critical applications, an unexpected fault or failure of the machine could lead to very high repair or replacement cost, or even catastrophic system failure. Therefore a robust and reliable health monitoring and fault diagnostic approach is desired, which could help in scheduling preventive maintenance to lengthen their lifespan and avoid machine failure. This dissertation presents a novel multi-faults diagnostic approach using search coils. These search coils are wound around armature teeth, so they typically need to be installed during manufacturing. But its immunity to high frequency harmonics makes it suitable for inverter/rectifier fed motors or generators, such as wind turbines and automotive systems. In addition, this method does not require the knowledge of proprietary constructional details of the machine. Since the electromagnetic flux is directly measured in this method, it provides much more information than any other scheme: the direction of eccentricity and the location of shorted windings. Furthermore, this method is also capable of evaluating the severity of each fault, which is of significant importance in mission critical applications such as automotive, aerospace and military applications. In addition to these uses, the search coils can be used as a universal sensor to estimate phase current or rotor position, which are critical information in a PMSM close-loop control, which allow it to work as a backup sensor for fault tolerant operation. The proposed fault detection scheme and universal sensor concept have been tested under several scenarios with Finite Element Analysis and experimentally validated.
Ph.D. in Electrical Engineering, May 2012
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Title: CELL-MATRIX INTERACTIONS IN ADIPOSE TISSUE FUNCTION
Creator: Vaicik, Marcella K.
Date: 2015, 2015-07
Description: The overall goal of this work is to apply in vivo and in vitro models to study the basement membrane protein laminin α4 (lama4) in adipocyte...
Show moreThe overall goal of this work is to apply in vivo and in vitro models to study the basement membrane protein laminin α4 (lama4) in adipocyte function. Adipose tissue accumulation, lipogenesis, and structure were examined in mice with a null mutation of the lama4 gene (Lama4−/−) and compared to wild-type animals (Lama4+/+). The Lama4−/−mice phenotype was investigated to evaluate if the differences were due specifically to the adipose tissue function. Physical activity and food intake does not differ between Lama4+/+ and Lama4−/− mice. However, Lama4−/− mice have a significantly increased metabolic rate at 25°C and 16°C compared to Lama4+/+ mice. In contrast, in thermoneutral conditions at 30°C both Lama4+/+ and Lama4−/− mice exhibit equivalent metabolic rates. Interestingly, when room temperature housed mice fat pads were evaluated with immunohistochemistry, Lama4−/− mice exhibit significantly increased UCP-1 expression in subcutaneous adipose. These results suggest that beiging, white to brown adipocytes, in subcutaneous adipose tissue in Lama4−/− mice may lead to decreased adipose tissue accumulation and improved metabolic function. While animal models indicate the absence of lama4 results in more beiging in subcutaneous adipose tissue, an in vitro tissue engineered model was developed to study the adipocyte function in a controlled microenvironment. Primary cell spheroids developed from Lama4+/+ and Lama4−/− were incorporated into synthetic poly(ethylene glycol) (PEG) hydrogels within a range of stiffnesses. When the cells were given the same chemical cues their functions differed depending upon microenvironment stiffness. Beige function in adipocyte cells in 3D can be influenced by matrix stiffness. In conclusion, the laminin alpha 4 basement membrane protein absence in adipose tissue results in adipocyte functional changes in vivo. The Lama4−/− mice have resistance to diet induced weight gain and increased metabolic rate at room temperature and when cold challenged. The Lama4−/− mice had increased beiging in the subcutaneous depot. Additionally, a tissue engineered model was developed to further study cell-ECM interactions first identified in an animal model. These in vivo findings and the engineered model of adipose tissue have great potential for studying obesity and other adipose related diseases. Future work will require continued interdisciplinary collaboration towards the successful identification and screening of novel therapeutics using engineered tissue models.
Ph.D. in Biomedical Engineering, July 2015
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