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Full-Text Articles in Engineering

Synchrophasor-Based Fault Location Detection And Classification, In Power Systems, Using Artificial Intelligence, Hemal Falak May 2019

Synchrophasor-Based Fault Location Detection And Classification, In Power Systems, Using Artificial Intelligence, Hemal Falak

Theses and Dissertations

With the introduction of sophisticated electronic gadgets which cannot sustain interruption in the provision of electricity, the need to supply uninterrupted and reliable power supply, to the consumers, has become a crucial factor in the present-day world. Therefore, it is customary to correctly identify fault locations in an electrical power network, in order to rectify faults and restore power supply in the minimum possible time. Many automated fault location detection algorithms have been proposed, however, prior art requires topological and physical information of the electrical power network. This thesis presents a new method of detecting fault locations, in transmission as ...


Cycle Assist, Tyler Matthews Jan 2019

Cycle Assist, Tyler Matthews

Williams Honors College, Honors Research Projects

The senior engineering design project presented in the paper that succeeds this, outlines the steps taken to design and implement an electronic bicycle that is able to keep a user’s heart-rate in a selected “intensity zone” though the use of an electronic motor and custom control circuitry. My portion of this project was to allow for safe and consistent power delivery to the rest of the electronics. That is to say, I built a battery pack and battery management system (BMS) to safely supply sufficient power to the rest of the electronics that were required for this project. In ...


Automatic Range Finding Bow Sight, Garrett Gill, Dillon Denny, Cory Verba Jan 2019

Automatic Range Finding Bow Sight, Garrett Gill, Dillon Denny, Cory Verba

Williams Honors College, Honors Research Projects

With the growing popularity of archery, a system designed to help an archer achieve the best shot possible becomes necessary. The Automatic Range Finding Bow Sight is a system that consists of a single pin sight controlled by a servo motor. The servo motor controls the sight pin by rotating a drive wheel that will move the pin up or down. The sight pin movement is based on a reading obtained by a built-in rangefinder and speed data input by the user. This data will then be compared to programmed lookup tables in order to find the appropriate pin position ...


Power Mobility Sensor Data Collection Verified Through Standardized Pediatric Assessments, Ayshka Elise Rodriguez-Velez Jan 2018

Power Mobility Sensor Data Collection Verified Through Standardized Pediatric Assessments, Ayshka Elise Rodriguez-Velez

UNF Graduate Theses and Dissertations

The collaboration between the School of Engineering and the Department of Physical Therapy at the University of North Florida has introduced the possibility of creating a new environment for pediatric physical therapy assessments. There are currently no methods for remotely monitoring children with impairments. However, with embedded sensor technology in the form of power mobility and accepted therapy assessment tools, remote monitoring can become a possibility. As a part of this work, a ride-on toy car was developed as a remote monitoring device and a case study with a child with a mobility impairment was used as a proof of ...


Fast Calculation Of Thévenin Equivalents For Real-Time Steady State Voltage Stability Estimation, Jorge Alberto Vélez Vásquez Jan 2016

Fast Calculation Of Thévenin Equivalents For Real-Time Steady State Voltage Stability Estimation, Jorge Alberto Vélez Vásquez

Graduate Theses and Dissertations

The purpose of this work is to present a novel approach to quickly update Thévenin equivalents of multi nodal systems, which can be used to calculate long-term Voltage Stability Margins (VSMs) in real-time applications considering n-k contingencies in the grid. To accomplish this, a derivation of Thévenin equivalent parameters of a multi-port system is proposed, which are expressed in terms of the parameters of the Zbus of the network. Then, by using the matrix inversion lemma and Kron reductions, a new methodology to quickly update the Zbus of the system when n-k contingencies occur is explained. The speed of this ...


Accurate Spectral Testing Without Accurate Instrumentation, Li Xu Jan 2016

Accurate Spectral Testing Without Accurate Instrumentation, Li Xu

Graduate Theses and Dissertations

Analog-to-digital converters (ADCs) are becoming increasingly common in many systems in integrated circuits. Spectral testing is widely used to test the dynamic linearity performance of ADCs and waveform generators. With improvements in the performance of ADCs, it is becoming an expensive and challenging task to perform spectral testing using standard methods because of the requirement that the test instrumentation environment must satisfy several stringent conditions. In order to address these challenges and to decrease the test cost, in this dissertation, four new algorithms are proposed to perform accurate spectral testing of ADCs by relaxing three conditions required for standard spectral ...


Dual-Frequency Dual-Inductor Multiple-Outputs (Df-Dimo) Buck Converter Topologies With Fully-Integrated Output Filters, Yongjie Jiang Jan 2016

Dual-Frequency Dual-Inductor Multiple-Outputs (Df-Dimo) Buck Converter Topologies With Fully-Integrated Output Filters, Yongjie Jiang

Graduate Theses and Dissertations

In multi-core DSPs, there is a need for multiple independent power supplies to power the digital cores. Each power supply needs to have fast dynamic response and must support a wide range of output voltage with up to hundreds of mA load current. In this dissertation, the key performance metrics in power converter design are introduced, the advantages and dis-advantages of the conventional power converter topology are analyzed and a new Dual-Frequency Dual-Inductor Multiple-Output (DF-DIMO) buck converter topology is presented to improve the limitations of the conventional topologies. The proposed topology employs a dual-phase 20-MHz current-mode-controlled input stage to reduce ...


Microfluidic Devices For High-Throughput Plant Phenotyping And Bioenergy Harvesting From Microbes And Living Plants, Huawei Jiang Jan 2016

Microfluidic Devices For High-Throughput Plant Phenotyping And Bioenergy Harvesting From Microbes And Living Plants, Huawei Jiang

Graduate Theses and Dissertations

Microfluidics and micro/nanofabrication techniques provide powerful technological platforms to develop miniature bioassay devices for studying cellular and multicellular organisms. Microfluidic devices have many advantages over traditional counterparts, including good throughput due to parallel experiments, low infrastructural cost, fast reaction, reduced consumption of agent and reagent, and avoidance of contamination. This thesis is focused on the development of a microfluidic toolkit with several miniature devices to tackle important problems that the fields of plant phenotyping and bioenergy harvesting are facing. The ultimate goal of this research is to realize high-throughput screening methods for studying environment-genomics of plants through phenomics, and ...


Micro-Electro-Opto-Fluidic Systems For Biomedical Drug Screening And Electromagnetic Filtering And Cloaking Applications, Peng Liu Jan 2016

Micro-Electro-Opto-Fluidic Systems For Biomedical Drug Screening And Electromagnetic Filtering And Cloaking Applications, Peng Liu

Graduate Theses and Dissertations

Microfluidic is a multidisciplinary field that deals with the flow of liquid inside micro-meter size channels. In order to be considered as microfluidics, at least one dimension of the channel should be in the range of one micrometer or sub-millimeter. Microfluidic technology includes designing, manufacturing, formulating devices and processing the liquid. As numerous bio-science and engineering techniques have utilized microfluidics and highly integrated with this remarkable technology, the microfluidic platform technology has extended to several sub-techs: micro-scale analysis, soft-lithography fabrication, polymer science and processing, on-chip sensing and micro-scale fluid manipulation. Those sub-techs have been developed rapidly along with the booming ...


Probabilistic Insertion, Deletion And Substitution Error Correction Using Markov Inference In Next Generation Sequencing Reads, Vahid Noroozi Jan 2016

Probabilistic Insertion, Deletion And Substitution Error Correction Using Markov Inference In Next Generation Sequencing Reads, Vahid Noroozi

Graduate Theses and Dissertations

Error correction of noisy reads obtained from high-throughput DNA sequencers is an important problem since read quality significantly affects downstream analyses such as detection of genetic variation and the complexity and success of sequence assembly. Most of the current error correction algorithms are only capable of recovering substitution errors. In this work, Pindel, an algorithm that simultaneously corrects insertion, deletion and substitution errors in reads from next generation DNA sequencing platforms is presented. Pindel corrects insertion, deletion and substitution errors by modelling the sequencer output as emissions of an appropriately defined Hidden Markov Model (HMM). Reads are corrected to the ...


Green Cooperative Spectrum Sensing And Scheduling In Heterogeneous Cognitive Radio Networks, Abdulkadir Celik Jan 2016

Green Cooperative Spectrum Sensing And Scheduling In Heterogeneous Cognitive Radio Networks, Abdulkadir Celik

Graduate Theses and Dissertations

The motivation behind the cognitive radio networks (CRNs) is rooted in scarcity of the radio spectrum and inefficiency of its management to meet the ever increasing high quality of service demands. Furthermore, information and communication technologies have limited and/or expensive energy resources and contribute significantly to the global carbon footprint. To alleviate these issues, energy efficient and energy harvesting (EEH) CRNs can harvest the required energy from ambient renewable sources while collecting the necessary bandwidth by discovering free spectrum for a minimized energy cost. Therefore, EEH-CRNs have potential to achieve green communications by enabling spectrum and energy self-sustaining networks ...


Ultra-Small Low Power Temperature-To-Digital Converter And Verification Methods Of Analog Circuit With Trojan States, Yen-Ting Wang Jan 2016

Ultra-Small Low Power Temperature-To-Digital Converter And Verification Methods Of Analog Circuit With Trojan States, Yen-Ting Wang

Graduate Theses and Dissertations

Accurate, small and low-power CMOS temperature sensors designed for multi-position temperature monitoring of power management in multi-core processors are proposed. The temperature sensors utilize the temperature characteristics of the threshold voltage of a MOS transistors to sense temperature and are highly linear from 60°C to 90°C. This is the temperature range needed for the power management applications where temperature sensors are strategically placed at multiple locations in each core to protect the processor from temperature-induced reliability degradation. A temperature-to-digital converter (TDC) that does not require either a reference generator or an ADC is also introduced, and it exhibits ...


Pilot-1: Autonomous Fixed-Wing Aircraft Control System, Chris Millsap, Nathan Garvey, Faisal Hayat Jun 2015

Pilot-1: Autonomous Fixed-Wing Aircraft Control System, Chris Millsap, Nathan Garvey, Faisal Hayat

Interdisciplinary Design Senior Theses

In the past decade, the personal ownership of unmanned aerial vehicles has exploded in the US and around the world. The rapidly declining size and cost of integrated circuits, sensors and embedded micro-controllers has lead to a flourishing community of hobbyists designing flight controllers with levels of sophistication approaching those for government and military applications. The typical flight assisted controllers integrate data from the user's control system and an Inertial Measurement Unit (IMU) in order to keep the craft level and on course. Deriving mostly from the radio controlled (RC) hobby industry, the flight control technologies for both rotary ...


Study Of Electronic Characteristics Of Heterojunction With Intrinsic Thin-Layer Devices And Defect Density Profile Of Nanocrystalline Silicon Germanium Devices, Watson Paul Mulder Jan 2015

Study Of Electronic Characteristics Of Heterojunction With Intrinsic Thin-Layer Devices And Defect Density Profile Of Nanocrystalline Silicon Germanium Devices, Watson Paul Mulder

Graduate Theses and Dissertations

Heterojunction with Intrinsic Thin-layer (HIT) solar cells are an important photovoltaic technology, recently reaching record power conversion efficiencies. HIT cells hold advantages over the conventional crystalline Si solar cells, such as their fabrication at lower temperatures and their shorter fabrication time. It is important to understand the electronic characteristics and transport properties of HIT cells to continue to improve their efficiencies. The fundamental measurements of a HIT solar cell with an innovative n+/p/p+ structure are presented. We also report on a series of these HIT cells fabricated on wafers with different doping concentrations, observing the relationship between doping ...


Power Conversion Techniques In Nanometer Cmos For Low-Power Applications, Wei Fu Jan 2015

Power Conversion Techniques In Nanometer Cmos For Low-Power Applications, Wei Fu

Graduate Theses and Dissertations

As System-on-Chip (SoCs) in nanometer CMOS technologies grow larger, the power management process within these SoCs becomes very challenging. In the heart of this process lies the challenge of implementing energy-efficient and cost-effective DC-DC power converters. To address this challenge, this thesis studies in details three different aspects of DC-DC power converters and proposes potential solutions. First, to maximize power conversion efficiency, loss mechanisms must be studied and quantified. For that purpose, we provide comprehensive analysis and modeling of the various switching and conduction losses in low-power synchronous DC-DC buck converters in both Continuous Conduction Mode (CCM) and Discontinuous Conduction ...


Uncertainty In Power System Planning, Oluwaseyi Ayorinde Olatujoye Jan 2015

Uncertainty In Power System Planning, Oluwaseyi Ayorinde Olatujoye

Graduate Theses and Dissertations

Deterministic transmission planning is based on deterministic assumptions, by planning for a single forecasted set of conditions. The issue of adaptability in transmission and generation expansion planning has become important for planners in order to deal with future uncertainties. Adaptability is "the ability to change (or be changed) to fit changed circumstances" [ ]. Adaptability planning helps mitigate losses in unforeseen situations and exploit opportunities in expected situations. Adaptability also provides the opportunities to take alternative actions after events unfold. Adaptable plans can help reduce future costs and time, and it also reduces complexity associated with possible future changes to the existing ...


Methods Of Magnetic Field Switching For Biomedical And Power Applications, Narimdinda Robert Bouda Jan 2015

Methods Of Magnetic Field Switching For Biomedical And Power Applications, Narimdinda Robert Bouda

Graduate Theses and Dissertations

Surrounded by electromagnetic (EM) fields humans continuously interact and utilize EM fields for domestic devices, telecom systems, power systems and different medical applications including MRI (Magnetic Resonance Imaging) and TMS (Transcranial Magnetic Stimulation). During the last century, numerous new electronic devices and technologies have been developed leading to an exponential increase in exposure to Electromagnetic Fields. Although all of these applications are byproducts of Maxwell' experimentation, there are considerable differences in the way they interact with us.

In the treatment of noninvasive treatment of the human brain, the majority of the research has been mainly focused on realizing systems that ...


Slew-Rate Enhancement And Trojan State Avoiding For Fully-Differential Operational Amplifier, Chongli Cai Jan 2015

Slew-Rate Enhancement And Trojan State Avoiding For Fully-Differential Operational Amplifier, Chongli Cai

Graduate Theses and Dissertations

Operational amplifiers are fundamental building blocks in modern analog and mixed-signal systems such as data converters, switched-capacitor circuits, and filters. The fully-differential structure is extensively used in these applications because of its improved dynamic performance with respect to such aspects as signal-to-noise ratio (SNR) and total harmonic distortion (THD) when compared to its single-ended counterpart. In some of these applications, the fully-differential amplifier is required to have fast transient settling time without slew-rate limitations. Power consumption also must be taken into consideration because low power consumption can significantly reduce a battery's weight and size, and extend its life-time. A ...


Unconventional Elastomeric Microsystems: Fabrication And Application, Jungwook Paek Jan 2015

Unconventional Elastomeric Microsystems: Fabrication And Application, Jungwook Paek

Graduate Theses and Dissertations

Elastomer-based microsystems hold great promise for a diverse range of applications such as rapid prototyping of lab-on-a-chip device, soft-MEMS, and soft-robotics. For better performance in such applications, unconventional elastomeric structures in terms of size, shape, and patterning trajectory, have been intensely sought after in microtechnology but their realization has been a continuous challenge. Here, as my dissertation work, I present new microfabrication schemes which enable the realizations of unconventional PDMS structures, and their applications, which will enrich the field of soft-microsystems.

First, I present a new fabrication scheme for the realization of cylindrical microfluidic (MF) channels with 3D trajectories based ...


Correctness Results For On-Line Robust Principal Components Analysis, Brian Thomas Lois Jan 2015

Correctness Results For On-Line Robust Principal Components Analysis, Brian Thomas Lois

Graduate Theses and Dissertations

This work studies two interrelated problems - online robust PCA (RPCA) and online low-rank matrix completion (MC). In recent work by Candes et al., RPCA has been defined as a problem of separating a low-rank matrix (true data), L:=[ℓ₁, ℓ₂, ... ℓt, ... , ℓtmax and a sparse matrix (outliers), S:=[x₁, x₂, ... xt, ..., xtmax] from their sum, M:=L+S. Our work uses this definition of RPCA. An important application where both these problems occur is in video analytics in trying to separate sparse foregrounds (e.g., moving objects) and slowly changing backgrounds.

While there has been a large amount of recent ...


Droplet Actuator System For Molecular Diagnostic Applications, Riley Brien Jan 2015

Droplet Actuator System For Molecular Diagnostic Applications, Riley Brien

Graduate Theses and Dissertations

In biological research, routine liquid handling operations require considerable human effort and manual labor. For this reason, experiments in clinical laboratories are time-consuming and thus expensive. Recently, advances in point-of-care “lab-on-a-chip” systems have allowed more efficient ways of sample handling and analysis. Such systems often operate by automated manipulation of discrete liquid droplets, and are increasing sought to improve experimental throughput. Various techniques have been developed to manipulate discrete droplets, such as digital microfluidics, surface acoustic waves, and texture ratchets. In this thesis, a novel droplet actuation system is presented that can be applied for molecular diagnostic tests. The system ...


Radio Frequency And Capacitive Sensors For Dielectric Characterization Of Low-Conductivity Media, Robert Thomas Sheldon Jan 2015

Radio Frequency And Capacitive Sensors For Dielectric Characterization Of Low-Conductivity Media, Robert Thomas Sheldon

Graduate Theses and Dissertations

Low-conductivity media are found in a vast number of applications, for example as electrical insulation or as the matrix polymer in high strength-to-weight ratio structural composites. In some applications, these materials are subjected to extreme environmental, thermal, and mechanical conditions that can affect the material's desired performance. In a more general sense, a medium may be comprised of one or more layers with unknown material properties that may affect the desired performance of the entire structure. It is often, therefore, of great import to be able to characterize the material properties of these media for the purpose of estimating ...


A Broadband Bistable Piezoelectric Cantilever-Based Vibration Energy Harvester With Nonlinear High Power Extraction, Kanishka Aman Singh Jan 2015

A Broadband Bistable Piezoelectric Cantilever-Based Vibration Energy Harvester With Nonlinear High Power Extraction, Kanishka Aman Singh

Graduate Theses and Dissertations

This work presents a nonlinear vibration energy harvester, which combines a nonlinear bistable broadband piezoelectric cantilever used to transduce ambient vibration energy, with synchronized capture for efficient harvesting over broadband sources. An accurate model of the bistable transducer, that augments the Butterworth van Dyke piezoelectric model to capture the external magnetic force added as a bias to the external vibrations, is presented. Its validity has been demonstrated through physical implementation and experimental validation against simulation of the mathematical model. For efficient extraction of the transduced energy, nonlinear extraction circuits, namely synchronous charge extraction (SCE) and parallel synchronized switch harvesting on ...


Dynamic Optimization Based Reactive Power Planning For Improving Short-Term Voltage Performance, Magesh Kumar Paramasivam Jan 2015

Dynamic Optimization Based Reactive Power Planning For Improving Short-Term Voltage Performance, Magesh Kumar Paramasivam

Graduate Theses and Dissertations

Short term voltage stability in the form of delayed voltage recovery (FIDVR) poses a significant threat to system stability and reliability. This work examines the voltage instability issue in a power system with dense concentration of induction motor loads and applies dynamic VAR injection as a counter-measure to ensure short term voltage stability following a large disturbance. The dynamic behavior of motor loads, such as decelerating and stalling, is considered as the major cause of FIDVR incidents especially during summer peak load conditions in areas where low inertia single-phase air conditioning (A/C) motors comprise a significant portion of the ...


Energy Efficiency In Cognitive Radio Network: Study Of Cooperative Sensing Using Different Channel Sensing Methods, Chenxuan Cui Jan 2015

Energy Efficiency In Cognitive Radio Network: Study Of Cooperative Sensing Using Different Channel Sensing Methods, Chenxuan Cui

Graduate Theses and Dissertations

When cognitive radio (CR) operates, it starts by sensing spectrum and looking for idle bandwidth. There are several methods for CR to make a decision on either the channel is occupied or idle, for example, energy detection scheme, cyclostationary detection scheme and matching filtering detection scheme [1]. Among them, the most common method is energy detection scheme because of its algorithm and implementation simplicities [2]. There are two major methods for sensing, the first one is to sense single channel slot with varying bandwidth, whereas the second one is to sense multiple channels and each with same bandwidth. After sensing ...


Development Of Smartphone-Based Spectroscopy Instruments For Diagnostic Test Analysis, Benjamin Jin Seong Ch'ng Jan 2015

Development Of Smartphone-Based Spectroscopy Instruments For Diagnostic Test Analysis, Benjamin Jin Seong Ch'ng

Graduate Theses and Dissertations

The latest generation of smartphones are more powerful than the first computer that sent the man to the moon. These smartphones are increasingly seen as handheld computers due to the capabilities that can be done with smartphones. Therefore, in this thesis, we will demonstrate the utilization of a smartphone-based spectrometer using the CMOS CCD chip of the camera. The characterization and integration between the smartphone and spectrometer is done to ensure robust and reliable results. The smartphone-based spectrometer is able to measure accurately and made to be comparable to industrial spectrometers. This research was done in order to attempt to ...


Spectral Diffusion Map Approach For Structural Health Monitoring Of Wind Turbine Blades Using Distributed Sensors, Venkatesh Chinde Jan 2015

Spectral Diffusion Map Approach For Structural Health Monitoring Of Wind Turbine Blades Using Distributed Sensors, Venkatesh Chinde

Graduate Theses and Dissertations

Distributed Sensor Networks (DSN) has emerged as a sensing paradigms in the structural engineering field due to the application of Structural Health Monitoring (SHM) for large-scale structures which results in accurately diagnosing the health of structures and enhancing the reliability and robustness of monitoring systems. The multisensor network greatly enhances the feasibility of applying SHM and also provides awareness of structural damage. In this work, we develop data-driven method for the diagnosis of damage in mechanical structures using an array of distributed sensors. The proposed approach relies on comparing intrinsic geometry of data sets corresponding to the undamage and damage ...


Study Of Transport Properties And Defect Density Profile In Nanocrystalline Silicon Germanium Devices, Siva Konduri Jan 2015

Study Of Transport Properties And Defect Density Profile In Nanocrystalline Silicon Germanium Devices, Siva Konduri

Graduate Theses and Dissertations

Nanocrystalline Silicon-Germanium (nc-SiGe:H) is a useful material for photovoltaic devices and photo-detectors. Its bandgap can be tuned between Si (~1.1 eV) and Ge (~0.7 eV) by changing the alloy composition during growth. The material exhibits a good absorption extending to the infrared region even with thin layers. However previous work has shown that devices with higher Ge content have poor device performance. Also, very little work has been done previously to measure and understand the defect spectrum of nanocrystalline (Si,Ge). Defects control recombination, and hence, the performance of solar cell devices.

This work deals with studying ...


Fast Estimation Of Nonlinearities In Atomic Force Microscopy, Wenyu Wang Jan 2015

Fast Estimation Of Nonlinearities In Atomic Force Microscopy, Wenyu Wang

Graduate Theses and Dissertations

We propose a fast method to reconstruct the curve of tip-surface force v.s. distance

in Atomic Force Microscopy (AFM). A precise and fast force curve reconstruction can

help improve research in material science, biological science, chemistry, etc. Existing

techniques require multiple sinusoids at the input to introduce intermodulation terms,

i.e., exponential components at equally spaced frequencies, and the estimation is done

by balancing those terms. Instead of using intermodulation terms, our method tries to

balance time domain samples. The method is based on the assumption that a discrete

model approximates the continuous AFM model well when sampled at ...


Novel Acceleration Approaches Of Accurate And Efficient Modeling Of High Speed Interconnects In Layered Media, Hongsheng Xu Jan 2015

Novel Acceleration Approaches Of Accurate And Efficient Modeling Of High Speed Interconnects In Layered Media, Hongsheng Xu

Graduate Theses and Dissertations

Accurate modeling of interconnect structures is an important issue in modern high frequency circuit and chip design; such as the accurate computation of the frequency dependent internal impedance of interconnect structures, like wires and conducting

strips, and the accurate and efficient electromagnetic (EM) modeling for shielded microstrip structures, especially in multilayered medium.

In the first part of this dissertation, a rigorous volume integral equation (VIE) is developed for the current distributions over two-dimensional conducting cylinders.

For very low frequencies, it can be reduced to the widely-used quasi-static approximation. The different VIEs, surface integral equation (SIE), and partial differential equation (PDE ...