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Articles 31 - 51 of 51
Full-Text Articles in Engineering
Flight Control And Hardware Design Of Multi-Rotor Systems, Nathan M. Zimmerman
Flight Control And Hardware Design Of Multi-Rotor Systems, Nathan M. Zimmerman
Master's Theses (2009 -)
This thesis overviews crucial concepts involved in achieving quadcopter flight such as orientation estimation and control system implementation. This thesis also presents researchers with comprehensive hardware and software specifications for a quadcopter system. The primary application for this system would be for research with regards to the implementation of advance control techniques as well as data acquisition. Key constructs of this system include hardware software specifications for a flight controller, the radio system, and the sensorless brushless motor controllers. Firstly, the thesis starts by developing a reference frame and a mathematical model for the quadcotper system. Next, flight orientation estimation …
Design Optimization Of Permanent Magnet Machines Over A Target Operating Cycle Using Computationally Efficient Techniques, Alireza Fatemi
Design Optimization Of Permanent Magnet Machines Over A Target Operating Cycle Using Computationally Efficient Techniques, Alireza Fatemi
Dissertations (1934 -)
The common practices of large-scale finite element (FE) model-based design optimization of permanent magnet synchronous machines (PMSMs) oftentimes aim at improving the machine performance at the rated operating conditions, thus overlooking the performance treatment over the entire range of operation in the constant torque and extended speed regions. This is mainly due to the computational complexities associated with several aspects of such large-scale design optimization problems, including the FE-based modeling techniques, large number of load operating points for load-cycle evaluation of the design candidates, and large number of function evaluations required for identification of the globally optimal design solutions. In …
Benefits Of Considering More Than Temperature Acceleration For Gan Hemt Life Testing, Ronald A. Coutu Jr., Robert A. Lake, Bradley D. Christiansen, Eric R. Heller, Christopher A. Bozada, Brian S. Poling, Glen D. Via, James P. Theimer, Stephen E. Tetlak, Ramakrishna Vetury, Jeffrey B. Shealy
Benefits Of Considering More Than Temperature Acceleration For Gan Hemt Life Testing, Ronald A. Coutu Jr., Robert A. Lake, Bradley D. Christiansen, Eric R. Heller, Christopher A. Bozada, Brian S. Poling, Glen D. Via, James P. Theimer, Stephen E. Tetlak, Ramakrishna Vetury, Jeffrey B. Shealy
Electrical and Computer Engineering Faculty Research and Publications
The purpose of this work was to investigate the validity of Arrhenius accelerated-life testing when applied to gallium nitride (GaN) high electron mobility transistors (HEMT) lifetime assessments, where the standard assumption is that only critical stressor is temperature, which is derived from operating power, device channel-case, thermal resistance, and baseplate temperature. We found that power or temperature alone could not explain difference in observed degradation, and that accelerated life tests employed by industry can benefit by considering the impact of accelerating factors besides temperature. Specifically, we found that the voltage used to reach a desired power dissipation is important, and …
Tunable Split-Ring Resonators Using Germanium Telluride, C. H. Kodama, Ronald A. Coutu Jr.
Tunable Split-Ring Resonators Using Germanium Telluride, C. H. Kodama, Ronald A. Coutu Jr.
Electrical and Computer Engineering Faculty Research and Publications
We demonstrate terahertz (THz) split-ring resonator (SRR) designs with incorporated germanium telluride (GeTe) thin films. GeTe is a chalcogenide that undergoes a nonvolatile phase change from the amorphous to crystalline state at approximately 200 degrees C, depending on the film thickness and stoichiometry. The phase change also causes a drop in the material’s resistivity by six orders of magnitude. In this study, two GeTe-incorporated SRR designs were investigated. The first was an SRR made entirely out of GeTe and the second was a gold SRR structure with a GeTe film incorporated into the gap region of the split ring. These …
Conceptual Design Of Sleeve Rotor Synchronous Reluctance Motor For Traction Applications, Patel B. Reddy, Kevin Grace, Ayman M. El-Refaie
Conceptual Design Of Sleeve Rotor Synchronous Reluctance Motor For Traction Applications, Patel B. Reddy, Kevin Grace, Ayman M. El-Refaie
Electrical and Computer Engineering Faculty Research and Publications
Synchronous reluctance machines are very appealing for high speed traction motor design due to their robustness, simple structure, absence of magnets, and simple control. The absence of magnets means that synchronous reluctance (SynRel) machines are not susceptible to price variability and sustainability of rare-earth materials. Moreover, there are no concerns about demagnetisation or uncontrolled generation mode. However, the challenge of achieving a good constant power to speed ratio is dependent on the mechanical aspects of the design. Conventional SynRel designs perform poorly compared with the permanent magnet machines due to the presence of bridges and/or centre posts in absence of …
Development Of A Wireless Mobile Computing Platform For Fall Risk Prediction, Akm Jahangir Alam Majumder
Development Of A Wireless Mobile Computing Platform For Fall Risk Prediction, Akm Jahangir Alam Majumder
Dissertations (1934 -)
Falls are a major health risk with which the elderly and disabled must contend. Scientific research on smartphone-based gait detection systems using the Internet of Things (IoT) has recently become an important component in monitoring injuries due to these falls. Analysis of human gait for detecting falls is the subject of many research projects. Progress in these systems, the capabilities of smartphones, and the IoT are enabling the advancement of sophisticated mobile computing applications that detect falls after they have occurred. This detection has been the focus of most fall-related research; however, ensuring preventive measures that predict a fall is …
Novel Convergence Results In Nonlinear Filtering, Jennifer Lynn Bonniwell
Novel Convergence Results In Nonlinear Filtering, Jennifer Lynn Bonniwell
Dissertations (1934 -)
In this dissertation, the discrete-time extended Kalman filter is analyzed for its ability to attenuate finite-energy disturbances, known as the H-infinity property. Though the extended Kalman filter is designed to be a locally optimal minimum variance estimator, this dissertation proves that it has additional properties, such as H-infinity. This analysis is performed with the extended Kalman filter in direct form. Since this form reduces assumptions placed on the system in previous works on convergence and H-2 properties of the extended Kalman filter, the extended Kalman filter used as a nonlinear observer for noise-free models is revisited using the direct form …
Least-Squares Mapping From Kinematic Data To Acoustic Synthesis Parameters For Rehabilitative Acoustic Learning, Xiangyu Zhou
Least-Squares Mapping From Kinematic Data To Acoustic Synthesis Parameters For Rehabilitative Acoustic Learning, Xiangyu Zhou
Master's Theses (2009 -)
Thousands of people suffer from dysarthria resulting from neurological injury of the motor component of the motor-speech system, and need to rely on alternative methods to communicate in daily life, such as body language or text-to-speech [1] . However, there are currently very few effective rehabilitative therapies for helping these patients improve their speech. Because of this, research is needed to develop better rehabilitative therapies. One such area of research is the use of involuntary acoustic learning. The Speech and Swallowing lab at Marquette University has an Electromagnetic Articulography (EMA) system to collect kinematic data and a software system called …
Investigation Of The Use Of A Plasticizer-Polymer Sensor Coating With Improved Long-Term Stability In The Liquid Phase, Laura Jeanne Alderson
Investigation Of The Use Of A Plasticizer-Polymer Sensor Coating With Improved Long-Term Stability In The Liquid Phase, Laura Jeanne Alderson
Master's Theses (2009 -)
Benzene is one of the volatile organic compounds present in crude oil and gasoline. Leakage from underground storage tanks or hazardous waste sites can introduce benzene contamination into nearby groundwater. Benzene is a known carcinogen and its exposure is limited by the Environmental Protection Agency to 5 parts per billion (ppb) in drinking water. Early, accurate detection of the presence of benzene contamination in groundwater supplies is extremely important. Shear horizontal surface acoustic wave (SH-SAW) devices with a chemically sensitive coating can be used for the detection of volatile organic compounds in liquid, such as BTEX (benzene, toluene, ethylbenzene and …
Integrating Nanosphere Lithography In Device Fabrication, Tod V. Laurvick, Ronald A. Coutu Jr., Robert A. Lake
Integrating Nanosphere Lithography In Device Fabrication, Tod V. Laurvick, Ronald A. Coutu Jr., Robert A. Lake
Electrical and Computer Engineering Faculty Research and Publications
This paper discusses the integration of nanosphere lithography (NSL) with other fabrication techniques, allowing for nano-scaled features to be realized within larger microelectromechanical system (MEMS) based devices. Nanosphere self-patterning methods have been researched for over three decades, but typically not for use as a lithography process. Only recently has progress been made towards integrating many of the best practices from these publications and determining a process that yields large areas of coverage, with repeatability and enabled a process for precise placement of nanospheres relative to other features. Discussed are two of the more common self-patterning methods used in NSL (i.e. …
Improved Sensitivity Mems Cantilever Sensor For Terahertz Photoacoustic Spectroscopy, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie
Improved Sensitivity Mems Cantilever Sensor For Terahertz Photoacoustic Spectroscopy, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie
Electrical and Computer Engineering Faculty Research and Publications
In this paper, a microelectromechanical system (MEMS) cantilever sensor was designed, modeled and fabricated to measure the terahertz (THz) radiation induced photoacoustic (PA) response of gases under low vacuum conditions. This work vastly improves cantilever sensitivity over previous efforts, by reducing internal beam stresses, minimizing out of plane beam curvature and optimizing beam damping. In addition, fabrication yield was improved by approximately 50% by filleting the cantilever’s anchor and free end to help reduce high stress areas that occurred during device fabrication and processing. All of the cantilever sensors were fabricated using silicon-on-insulator (SOI) wafers and tested in a custom …
Robust Non-Permanent Magnet Motors For Vehicle Propulsion, Tsarajidy Raminosoa, David A. Torrey, Ayman M. El-Refaie, Di Pan, Stefan Grubic, Kevin Grace
Robust Non-Permanent Magnet Motors For Vehicle Propulsion, Tsarajidy Raminosoa, David A. Torrey, Ayman M. El-Refaie, Di Pan, Stefan Grubic, Kevin Grace
Electrical and Computer Engineering Faculty Research and Publications
There has been growing interest in electrical machines that reduce or eliminate rare-earth material content. Traction applications are among the key applications where reducing cost and hence reduction or elimination of rare-earth materials is a key requirement. This paper will assess the potential of three non-permanent magnet options in the context of vehicle propulsion applications: 1) a conventional Switched Reluctance Machine (SRM), 2) a DC-biased Reluctance Machine (DCRM) and, 3) a Wound Field Flux Switching Machine (WFFSM). The three machines were designed to achieve the hybrid vehicle traction requirements of 55kW peak and 30kW continuous over a speed range going …
Acoustic Sequences In Non-Human Animals: A Tutorial Review And Prospectus, Arik Kershenbaum, Daniel T. Blumstein, Marie A. Roch, Çağlar Akçay, Gregory Backus, Mark A. Bee, Kirsten Bohn, Yan Cao, Gerald Carter, Cristiane Cäsar, Michael Coen, Stacy L. Deruiter, Laurance Doyle, Shimon Edelman, Ramon Ferreri Cancho, Todd M. Freeberg, Ellen C. Garland, Morgan Gustison, Heidi E. Harley, Chloé Huetz, Melissa Hughes, Julia Hyland Bruno, Amiyaal Ilany, Dezhe Z. Jin, Michael T. Johnson, Chenghui Ju, Jeremy Karnowski, Bernard Lohr, Marta B. Manser, Brenda Mccowan, Eduardo Mercado Iii, Peter M. Narins, Alex Piel, Megan Rice, Roberta Salmi, Kazutoshi Sasahara, Laela Sayigh, Yu Shiu, Charles Taylor, Edgar E. Vallejo, Sara Waller, Veronica Zamora Gutierrez
Acoustic Sequences In Non-Human Animals: A Tutorial Review And Prospectus, Arik Kershenbaum, Daniel T. Blumstein, Marie A. Roch, Çağlar Akçay, Gregory Backus, Mark A. Bee, Kirsten Bohn, Yan Cao, Gerald Carter, Cristiane Cäsar, Michael Coen, Stacy L. Deruiter, Laurance Doyle, Shimon Edelman, Ramon Ferreri Cancho, Todd M. Freeberg, Ellen C. Garland, Morgan Gustison, Heidi E. Harley, Chloé Huetz, Melissa Hughes, Julia Hyland Bruno, Amiyaal Ilany, Dezhe Z. Jin, Michael T. Johnson, Chenghui Ju, Jeremy Karnowski, Bernard Lohr, Marta B. Manser, Brenda Mccowan, Eduardo Mercado Iii, Peter M. Narins, Alex Piel, Megan Rice, Roberta Salmi, Kazutoshi Sasahara, Laela Sayigh, Yu Shiu, Charles Taylor, Edgar E. Vallejo, Sara Waller, Veronica Zamora Gutierrez
Electrical and Computer Engineering Faculty Research and Publications
Animal acoustic communication often takes the form of complex sequences, made up of multiple distinct acoustic units. Apart from the well-known example of birdsong, other animals such as insects, amphibians, and mammals (including bats, rodents, primates, and cetaceans) also generate complex acoustic sequences. Occasionally, such as with birdsong, the adaptive role of these sequences seems clear (e.g. mate attraction and territorial defence). More often however, researchers have only begun to characterise – let alone understand – the significance and meaning of acoustic sequences. Hypotheses abound, but there is little agreement as to how sequences should be defined and analysed. Our …
Online Chemical Sensor Signal Processing Using Estimation Theory: Quantification Of Binary Mixtures Of Organic Compounds In The Presence Of Linear Baseline Drift And Outliers, Karthick Sothivelr, Florian Bender, Fabien Josse, Edwin E. Yaz, Antonio J. Ricco, Mary E. Mohler
Online Chemical Sensor Signal Processing Using Estimation Theory: Quantification Of Binary Mixtures Of Organic Compounds In The Presence Of Linear Baseline Drift And Outliers, Karthick Sothivelr, Florian Bender, Fabien Josse, Edwin E. Yaz, Antonio J. Ricco, Mary E. Mohler
Electrical and Computer Engineering Faculty Research and Publications
Compact sensor systems for on-site monitoring of groundwater for trace organic compounds in the liquid phase are currently under development in our laboratories. Potential challenges include sensor baseline drift and the presence of outliers in the data, along with difficulties extracting the contribution of individual BTEX compound (benzene, toluene, ethylbenzene, and xylenes) from the sensor response to mixtures containing multiple chemically similar compounds. As a first step, the approach presented here permits online estimation of analyte concentrations in binary mixtures of BTEX compounds in the presence of linear baseline drift and outliers. This paper investigates a sensor signal-processing approach based …
Robust Multi-Criteria Optimal Fuzzy Control Of Discrete-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz
Robust Multi-Criteria Optimal Fuzzy Control Of Discrete-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz
Electrical and Computer Engineering Faculty Research and Publications
This paper presents a novel fuzzy control design of discrete-time nonlinear systems with multiple performance criteria. The purpose behind this work is to improve the traditional fuzzy controller performance to satisfy several performance criteria simultaneously to secure quadratic optimality with an inherent stability property together with a dissipativity type of disturbance reduction. The Takagi–Sugeno-type fuzzy model is used in our control system design. By solving a linear matrix inequality at each time step, the optimal control solution can be found to satisfy mixed performance criteria. The effectiveness of the proposed technique is demonstrated by simulation of the control of the …
On The Analytical Formulation Of Excess Noise In Avalanche Photodiodes With Dead Space, Erum Jamil, Jeng Shiuh Cheong, J.P.R. David, Majeed M. Hayat
On The Analytical Formulation Of Excess Noise In Avalanche Photodiodes With Dead Space, Erum Jamil, Jeng Shiuh Cheong, J.P.R. David, Majeed M. Hayat
Electrical and Computer Engineering Faculty Research and Publications
Simple, approximate formulas are developed to calculate the mean gain and excess noise factor for avalanche photodiodes using the dead-space multiplication theory in the regime of small multiplication width and high applied electric field. The accuracy of the approximation is investigated by comparing it to the exact numerical method using recursive coupled integral equations and it is found that it works for dead spaces up to 15% of the multiplication width, which is substantial. The approximation is also tested for real materials such as GaAs, InP and Si for various multiplication widths, and the results found are accurate within ∼ …
Robust Multi-Criteria Optimal Fuzzy Control Of Continuous-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz
Robust Multi-Criteria Optimal Fuzzy Control Of Continuous-Time Nonlinear Systems, Xin Wang, Edwin E. Yaz
Electrical and Computer Engineering Faculty Research and Publications
This paper presents a novel fuzzy control design of continuous-time nonlinear systems with multiple performance criteria. The purpose behind this work is to improve the traditional fuzzy controller performance to satisfy several performance criteria simultaneously to secure quadratic optimality with inherent stability property together with dissipativity type of disturbance reduction. The Takagi– Sugeno fuzzy model is used in our control system design. By solving the linear matrix inequality at each time step, the control solution can be found to satisfy the mixed performance criteria. The effectiveness of the proposed technique is demonstrated by simulation of the control of the inverted …
Sensor-Based Estimation Of Btex Concentrations In Water Samples Using Recursive Least Squares And Kalman Filter Techniques, Karthick Sothivelr, Florian Bender, Fabien Josse, Edwin E. Yaz, Antonio J. Ricco
Sensor-Based Estimation Of Btex Concentrations In Water Samples Using Recursive Least Squares And Kalman Filter Techniques, Karthick Sothivelr, Florian Bender, Fabien Josse, Edwin E. Yaz, Antonio J. Ricco
Electrical and Computer Engineering Faculty Research and Publications
This work investigates sensor signal processing approaches that can be used with a sensor system for direct on-site monitoring of groundwater, enabling detection and quantification of BTEX (benzene, toluene, ethylbenzene and xylene) compounds at μg/L (ppb) concentrations in the presence of interferents commonly found in groundwater. A model for the sensor response to water samples containing multiple analytes was first formulated based on experimental results. The first signal processing approach utilizes only RLSE (recursive least squares estimation) whereas the second, a two-step processing technique, utilizes both RLSE and bank of Kalman filters for the estimation process. The estimation techniques were …
Detection And Quantification Of Aromatic Hydrocarbon Compounds In Water Using Sh-Saw Sensors And Estimation-Theory-Based Signal Processing, Karthick Sothivelr, Florian Bender, Fabien Josse, Antonio J. Ricco, Edwin E. Yaz, Rachel E. Mohler, Ravi Kolhatkar
Detection And Quantification Of Aromatic Hydrocarbon Compounds In Water Using Sh-Saw Sensors And Estimation-Theory-Based Signal Processing, Karthick Sothivelr, Florian Bender, Fabien Josse, Antonio J. Ricco, Edwin E. Yaz, Rachel E. Mohler, Ravi Kolhatkar
Electrical and Computer Engineering Faculty Research and Publications
This work investigates a sensor system for direct groundwater monitoring, capable of aqueous-phase measurement of aromatic hydrocarbons at low concentrations (about 100 parts per billion (ppb)). The system is designed to speciate and quantify benzene, toluene, and ethylbenzene/xylenes (BTEX) in the presence of potential interferents. The system makes use of polymer-coated shear-horizontal surface acoustic wave devices and a signal processing method based on estimation theory, specifically a bank of extended Kalman filters (EKFs). This approach permits estimation of BTEX concentrations even from noisy data, well before the sensor response reaches equilibrium. To utilize estimation theory, an analytical model for the …
A Computationally Efficient Method For Calculation Of Strand Eddy Current Losses In Electric Machines, Alireza Fatemi, Dan M. Ionel, Nabeel Demerdash, Dave A. Staton, Rafal Wrobel, Yew Chuan Chong
A Computationally Efficient Method For Calculation Of Strand Eddy Current Losses In Electric Machines, Alireza Fatemi, Dan M. Ionel, Nabeel Demerdash, Dave A. Staton, Rafal Wrobel, Yew Chuan Chong
Electrical and Computer Engineering Faculty Research and Publications
In this paper, a fast finite element (FE)-based method for the calculation of eddy current losses in the stator windings of randomly wound electric machines with a focus on fractional slot concentrated winding (FSCW) permanent magnet (PM) machines will be presented. The method is particularly suitable for implementation in large-scale design optimization algorithms where a qualitative characterization of such losses at higher speeds is most beneficial for identification of the design solutions which exhibit the lowest overall losses including the ac losses in the stator windings. Unlike the common practice of assuming a constant slot fill factor, sf, for all …
Transient Analysis Of Analyte Desorption Due To Thermal Cycling With Varying Pulse Duration, Patrick Getz, Christopher Carron, Stephen M. Heinrich, Fabien Josse, Oliver Brand
Transient Analysis Of Analyte Desorption Due To Thermal Cycling With Varying Pulse Duration, Patrick Getz, Christopher Carron, Stephen M. Heinrich, Fabien Josse, Oliver Brand
Civil and Environmental Engineering Faculty Research and Publications
This paper introduces heating pulse duration modulation on a chemically sensitive, polymer-coated resonant cantilever platform for analyte discrimination during the desorption phase. As in our previous work, the embedded heaters enable real-time measurements of analyte sorption into the polymer film, without the need for traditional valve systems and reference gases [1-2]. This work particularly looks at the effects of varying pulse lengths on the sensor responses, while holding the heating power constant. A model differential equation is developed for the sensor response based on both the device sensitivity and transient response. This model can then be used together with estimation …