Electrical and Computer Engineering Commons^™

Genetic Algorithms In Stochastic Optimization And Applications In Power Electronics, Mengmei Liu

Theses and Dissertations--Electrical and Computer Engineering

Genetic Algorithms (GAs) are widely used in multiple fields, ranging from mathematics, physics, to engineering fields, computational science, bioinformatics, manufacturing, economics, etc. The stochastic optimization problems are important in power electronics and control systems, and most designs require choosing optimum parameters to ensure maximum control effect or minimum noise impact; however, they are difficult to solve using the exhaustive searching method, especially when the search domain conveys a large area or is infinite. Instead, GAs can be applied to solve those problems. And efficient computing budget allocation technique for allocating the samples in GAs is necessary because the real-life problems …

Mitigation Of Glass Weave Skew Using A Combination Of Low Dk Spread Glass, Multi-Ply Dielectric And Routing Direction, Kartheek Nalla

Masters Theses

"As the data rates increase into the multi-gigabit range, the bit periods fall in the range of few tens of picoseconds. At above few Gbps, it becomes very important to reduce skew between differential pairs as it can adversely impact the signal eye and thereby increase bit error rate. The goal of this study is to mitigate the skew contributed by woven glass fabric of PCB dielectrics.

The glass weave skew between differential pairs in a PCB occurs due to the difference in dielectric constants (DK) of glass and resin. This thesis aims to mitigate the skew by reducing the …

Electrosensitization Assists Cell Ablation By Nanosecond Pulsed Electric Field In 3d Cultures, Claudia Muratori, Andrei G. Pakhomov, Shu Xiao, Olga N. Pakhomova

Bioelectrics Publications

Previous studies reported a delayed increase of sensitivity to electroporation (termed "electrosensitization") in mammalian cells that had been subjected to electroporation. Electrosensitization facilitated membrane permeabilization and reduced survival in cell suspensions when the electric pulse treatments were split in fractions. The present study was aimed to visualize the effect of sensitization and establish its utility for cell ablation. We used KLN 205 squamous carcinoma cells embedded in an agarose gel and cell spheroids in Matrigel. A local ablation was created by a train of 200 to 600 of 300-ns pulses (50 Hz, 300-600 V) delivered by a two-needle probe with …

Intracellular Ros Mediates Gas Plasma-Facilitated Cellular Transfection In 2d And 3d Cultures, Dehui Xu, Biqing Wang, Yujing Xu, Zeyu Chen, Qinjie Cui, Yanjie Yang, Hailan Chen, Michael G. Kong

Bioelectrics Publications

This study reports the potential of cold atmospheric plasma (CAP) as a versatile tool for delivering oligonucleotides into mammalian cells. Compared to lipofection and electroporation methods, plasma transfection showed a better uptake efficiency and less cell death in the transfection of oligonucleotides. We demonstrated that the level of extracellular aqueous reactive oxygen species (ROS) produced by gas plasma is correlated with the uptake efficiency and that this is achieved through an increase of intracellular ROS levels and the resulting increase in cell membrane permeability. This finding was supported by the use of ROS scavengers, which reduced CAP-based uptake efficiency. In …

Electroporation By Subnanosecond Pulses, Iurii Semenov, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

Electropermeabilization of cell membranes by micro- and nanosecond-duration stimuli has been studied extensively, whereas effects of picosecond electric pulses (psEP) remain essentially unexplored. We utilized whole-cell patch clamp and Di-8-ANEPPS voltage-sensitive dye measurements to characterize plasma membrane effects of 500 ps stimuli in rat hippocampal neurons (RHN), NG108, and CHO cells. Even a single 500-ps pulse at 190kV/cm increased membrane conductance and depolarized cells. These effects were augmented by applying brief psEP bursts (5–125 pulses), whereas the rate of pulse delivery (8Hz–1kHz) played little role. psEP-treated cells displayed large inward current at negative membrane potentials but modest or no conductance …

Comparison Between Electropositive And Electronegative Cold Atmospheric-Pressure Plasmas: A Modelling Study, Ding X. Liu, Jia F. Li, Ai J. Yang, Xiao H. Wang, Ming Z. Rong, Michael G. Kong

Bioelectrics Publications

Cold atmospheric-pressure He + N₂ and He + O₂ plasmas are chosen as the representatives for electropositive and electronegative plasmas, of which the discharge characteristics are studied and then compared to each other by fluid models. As the increase of the impurity (N₂ or O₂) fraction from 0 to 10%, for He + N₂ plasmas the electron density and ion density increase, the spatiotemporal distributions of electron density, ion density, electron temperature and electron generation rate change a little. On contrast, for He + O₂ plasmas the electron density decreases, the ion density …

Disaster Preparedness And Response: A Survey Of U.S. Dental Hygienists, Brenda T. Bradshaw, Ann P. Bruhn, Tara L. Newcomb, Bridget T. Giles, Kathryn Simms

Dental Hygiene Faculty Publications

Purpose: The purpose of this study was to assess dental hygienists’ interests, current involvement, formal education, views, comfort levels, and intentions for involvement with disaster preparedness and response.

Methods: Dental hygienists (n=400) were asked to respond to a 21-item online survey. Data was analyzed using descriptive statistics, chi-square goodness-of-fit tests, and a paired-samples t-test. Common themes were identified and categorized from open-ended questions.

Results: A response rate of 84% (n=334) was obtained. Most respondents (97%) reported no involvement with disaster preparedness and response; however, a majority (86%) reported interest. Of those who indicated an interest in disaster preparedness and response, …

Beyond Conventional C-Plane Gan-Based Light Emitting Diodes: A Systematic Exploration Of Leds On Semi-Polar Orientations, Morteza Monavarian

Theses and Dissertations

Despite enormous efforts and investments, the efficiency of InGaN-based green and yellow-green light emitters remains relatively low, and that limits progress in developing full color display, laser diodes, and bright light sources for general lighting. The low efficiency of light emitting devices in the green-to-yellow spectral range, also known as the “Green Gap”, is considered a global concern in the LED industry. The polar c-plane orientation of GaN, which is the mainstay in the LED industry, suffers from polarization-induced separation of electrons and hole wavefunctions (also known as the “quantum confined Stark effect”) and low indium incorporation efficiency that …

An Architecture For Configuring An Efficient Scan Path For A Subset Of Elements, Arash Ashrafi

LSU Master's Theses

LaTeX4Web 1.4 OUTPUT Field Programmable Gate Arrays (FPGAs) have many modern applications. A feature of FPGAs is that they can be reconfigured to suit the computation. One such form of reconfiguration, called partial reconfiguration (PR), allows part of the chip to be altered. The smallest part that can be reconfigured is called a frame. To reconfigure a frame, a fixed number of configuration bits are input (typically from outside) to the frame. Thus PR involves (a) selecting a subset C Í S of k out of n frames to configure and (b) inputting the configuration bits for these k frames. …

High Resolution Time-Of-Arrival Ranging Of Wireless Sensor Nodes In Non-Homogenous Environments, Mohsen Jamalabdollahi

Dissertations, Master's Theses and Master's Reports

Wireless Sensor Networks (WSN) have emerging applications in homogeneous environments such as free space. In addition, WSNs are finding new applications in non-homogeneous (NH) media. All referred applications entail location information of measured data or observed event. Localization in WSNs is considered as the leading remedy, which refers to the procedure of obtaining the sensor nodes relative location utilizing range measurements. Localization via Time-of-Arrival (ToA) estimation has received considerable attention because of high precision and low complexity implementation, however, the traditional techniques are not feasible in NH media due to frequency dispersion of transmitted ranging waveform.

In this work, a …

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 …

Model Based Fault Diagnosis And Prognosis Of Class Of Linear And Nonlinear Distributed Parameter Systems Modeled By Partial Differential Equations, Jia Cai

Doctoral Dissertations

"With the rapid development of modern control systems, a significant number of industrial systems may suffer from component failures. An accurate yet faster fault prognosis and resilience can improve system availability and reduce unscheduled downtime. Therefore, in this dissertation, model-based prognosis and resilience control schemes have been developed for online prediction and accommodation of faults for distributed parameter systems (DPS). First, a novel fault detection, estimation and prediction framework is introduced utilizing a novel observer for a class of linear DPS with bounded disturbance by modeling the DPS as a set of partial differential equations.

To relax the state measurability …

High-Voltage-Gain Dc-Dc Power Electronic Converters -- New Topologies And Classification, Bhanu Prashant Reddy Baddipadiga

Doctoral Dissertations

"This dissertation proposes two new high-voltage-gain dc-dc converters for integration of renewable energy sources in 380/400V dc distribution systems. The first high-voltage-gain converter is based on a modified Dickson charge pump voltage multiplier circuit. The second high-voltage-gain converter is based on a non-inverting diode-capacitor voltage multiplier cell. Both the proposed converters offer continuous input current and low voltage stress on switches which make them appealing for applications like integration of renewable energy sources. The proposed converters are capable for drawing power from a single source or two sources while having continuous input current in both cases. Theoretical analysis of the …

Two-Dimensional Low-Resistance Contacts For High Performance Wse2 And Mos2 Transistors, Hsun Jen Chuang

Wayne State University Dissertations

ABSTRACT

TWO-DIMENSIONAL LOW-RESISTANCE CONTACTS FOR HIGH PERFORMANCE WSe2 and MoS2, TRANSISTORS

by

Hsun-jen Chuang

May 2016

Advisor: Dr. Zhixian Zhou

Major: Physics

Degree: Doctor of Philosophy

Two-dimensional layered materials beyond graphene such as transition metal dichalcogenides (TMDs) have attracted a lot of interests due to their superior property in many aspects. In this work, I am focusing on two TMD materials: WSe2 and MoS2. The main objective this work is to develop novel approaches to fabricating low-resistance ohmic contacts to TMDs for low power, high performance electronic applications. First, we used graphene as electrical contacts for WSe2 field-effect transistor with …

Dense Periodical Patterns In Photonic Devices: Technology For Fabrication And Device Performance, Sabarish Chandramohan

Wayne State University Dissertations

For the fabrication, focused ion beam parameters are investigated to successfully fabricate dense periodical patterns, such as gratings, on hard transition metal nitride such as zirconium nitride. Transition metal nitrides such as titanium nitride and zirconium nitride have recently been studied as alternative materials for plasmonic devices because of its plasmonic resonance in the visible and near-infrared ranges, material strength, CMOS compatibility and optical properties resembling gold. Coupling of light on the surface of these materials using sub-micrometer gratings gives additional capabilities for wider applications. Here we report the fabrication of gratings on the surface of zirconium nitride using gallium …

Modeling Based On 3d Finite Element Analysis And Experimental Study Of A 24-Slot 8-Pole Axial-Flux Permanent-Magnet Synchronous Motor For No Cogging Torque And Sinusoidal Back-Emf, Mehmet Güleç, Ersi̇n Yolaçan, Yücel Demi̇r, Oğuzhan Ocak, Meti̇n Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

This paper discusses cogging torque minimization techniques in surface-mounted, axial-flux, multirotor permanent magnet synchronous disc motors in order to eliminate cogging components and obtain sinusoidal back-EMF for low-speed applications. Cogging torque minimization techniques are examined in detail with a focus on magnet skewing and pole and rotor shifting in order to obtain zero cogging. Some magnet shape and rotor design alternatives with conventional skew planar magnets were investigated based on 3D finite element analysis (FEA). Improvements compared to unskewed reference axial-flux permanent magnet (AFPM) motor design are presented. A prototype AFPM motor was built and tested based on the analyses. …

How To Categorize Emotional Speech Signals With Respect To The Speaker's Degree Of Emotional Intensity, Salman Karimi, Mohammad Hossein Sedaaghi

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, classifying different emotional content of speech signals automatically has become one of the most important comprehensive inquiries. The main subject in this field is related to the improvement of the correct classification rate (CCR) resulting from the proposed techniques. However, a literature review shows that there is no notable research on finding appropriate parameters that are related to the intensity of emotions. In this article, we investigate the proper features to be employed in the recognition of emotional speech utterances according to their intensities. In this manner, 4 emotional classes of the Berlin Emotional Speech database, happiness, anger, fear, …

Peak-To-Average Power Ratio Reduction Using Backtracking Search Optimization Algorithm In Ofdm Systems, Necmi̇ Taşpinar, Yüksel Tokur Bozkurt

Turkish Journal of Electrical Engineering and Computer Sciences

A peak-to-average power ratio (PAPR) reduction method for an orthogonal frequency division multiplexing (OFDM) system based on a combination of a partial transmit sequence (PTS) scheme with the backtracking search optimization algorithm (BSA) is proposed. The PTS scheme shows good PAPR reduction performance; however, it requires a complex computation to search the set of optimum phase factors, especially for high-speed data transmissions. To minimize the complexity of the search for optimum phase factors, the PTS scheme is combined with the BSA. The BSA is a new and efficient population-based evolutionary search algorithm for real-valued optimization problems. A set of simulations …

Application Of A Time Delay Neural Network For Predicting Positive And Negative Links In Social Networks, Saghar Babakhanbak, Kaveh Kavousi, Fardad Farokhi

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Bayesian Compressive Sensing Framework For Spectrum Reconstruction In Rayleigh Fading Channels, Nadia Iqbal, Asad Mahmood, Sajjad Hussain, Abdul Ghafoor

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.