Engineering Commons^™

Assessment Of Sensory Abnormalities In Children With Asd Using Virtual Reality, Ankit Koirala

Theses and Dissertations

Sensory abnormality is one of the important characteristics of Autism Spectrum Disorder(ASD). A large number of studies suggest a strong connection between sensory abnormalities and ASD. Therefore, it is important to assess sensory abnormalities for diagnosis and intervention of ASD. In this thesis study, we aim to develop a virtual reality system that can measure sensory abnormalities in adolescents with ASD. Sensory abnormalities can affect all five senses: touch, vision, smell, taste and auditory. However, in this study, we focus on assessing sensory abnormality in vision and touch sensory processing. Twelve adolescents with ASD and 12 typically developing (TD) adolescents …

Vehicle Interior Access Deployable Worksurface Mechanism Concept Product Design, Premchand Gunachandran

Theses and Dissertations

by

Premchand Gunachandran

The University of Wisconsin-Milwaukee, 2019

Under the Supervision of Professor Mohammad Habibur Rahman

Easy access and adjusting the vehicle interior configuration to a variety of situations and uses is the general desire for any vehicle user. To meet such desire an attempt has been made in this study to conceptualize a design to develop a new mechatronic product called re-configurable vehicle interior console mechanism to deploy a worksurface (DWS), which will provide flexible use of the vehicle’s interior of both partial and fully autonomous vehicles. This re-configurable vehicle interior console will deploy the DWS using a power …

Scatter Reduction By Exploiting Behaviour Of Convolutional Neural Networks In Frequency Domain, Carlos Ivan Jerez Gonzalez

Theses and Dissertations

In X-ray imaging, scattered radiation can produce a number of artifacts that greatly

undermine the image quality. There are hardware solutions, such as anti-scatter grids.

However, they are costly. A software-based solution is a better option because it is

cheaper and can achieve a higher scatter reduction. Most of the current software-based

approaches are model-based. The main issues with them are the lack of flexibility, expressivity, and the requirement of a model. In consideration of this, we decided to apply

Convolutional Neural Networks (CNNs), since they do not have any of the previously

mentioned issues.

In our approach we split …

Cavity Environmental Control System Upgrade For Nasa’S Stratospheric Observatory For Infrared Astronomy, Ashraf Al-Hajjeh

Theses and Dissertations

The main goal of this project is to fulfill the need of a controller upgrade for the Cavity Environmental Control System (CECS) on NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) aircraft. The preceding controller had multiple disadvantages including operating in an unpressurized region, incomplete functionality implementation, limited fault and status monitoring capability, and reduced maintainability and reliability. The new controller will go through the NASA design process to fulfill all the requirements of CECS operation including complete functionality of all devices currently installed on the aircraft, added devices to improve fault and health monitoring, and overall improvement in maintainability and …

Exploring Methods For Studying Recoverability Of Shipboard Electrical Power Distribution Systems, Jacob David Gudex

Theses and Dissertations

Advancement of the technology included on ships, is changing the nature of loads installed on ships. Not only are there more loads than installed power generation, but advanced electrically powered weapons and sensors are changing the profile of the installed loads. These are challenges for future shipboard power systems design. Challenges which must be solved with careful distribution system planning, energy storage integration, and selection of individual power electronic converters within the ship. Different topologies and distribution systems have differing fault isolation and recovery (FIR) capability sets, which affects ship survivability. Furthermore, different FIR capability sets, operate at different speeds. …

Advanced Metering Infrastructure Security With Software-Defined Network In Smart Grid, Yi-Chen Chung

Theses and Dissertations

The Advanced Metering Infrastructure (AMI) is the most important and basic element in the Smart Grid systems. Technologies grow complicated as the world becomes more convenient. Power grid, smart building, electric vehicles, and other technology need to be managed and maintained flawlessly in case of the possibility of cyberattacks to shut down all the systems and result in huge loss economically or potentially affect people's life. It is important to use communication technologies to provide many functions including facilitate bidirectional communications and remote controls. Since AMI needs to be widely deployed to each home user, power companies are required to …

Light Scattering In Diffraction Limit Infrared Imaging, Ghazal Azarfar

Theses and Dissertations

Fourier Transform Infrared (FTIR) microspectroscopy is a noninvasive technique for chemical imaging of micrometer size samples. Employing an infrared microscope, an infrared source and FTIR spectrometer coupled to a microscope with an array of detectors (128 x 128 detectors), enables collecting combined spectral and spatial information simultaneously. Wavelength dependent images are collected, that reveal biochemical signatures of disease pathology and cell cycle. Single cell biochemistry can be evaluated with this technique, since the wavelength of light is comparable to the size of the objects of interest, which leads to additional spectral and spatial effects disturb biological signatures and can confound …

Sensing With Geometry-Dependent Magnetostriction Via An Embedded Fiber Bragg Grating, David Frailey

Theses and Dissertations

Fiber optic current sensors (FOCSs) have unique advantages in electromagnetic interference

immunity and direct current measurements. Here, magnetostrictive composites and

their interactions with embedded ber Bragg gratings (FBG) were explored to form novel

FOCSs with predictable and temperature-independent sensitivity. Magnetostrictive, particularly

Terfenol-D/epoxy, composites maintain the mangetostrictive expansion under an

external magnetic eld while gaining

exibility in engineering. In contrast to ordinary strain

gauges, an embedded FBG can provide an optical signal inferring simultaneously a strain

and its gradient inside a composite. In principle, the sensing of strain gradient is thermally

independent. Creating appropriate geometries for magnetostrictive composites enables the

conversion …

Multi-Tap Extended Kalman Filter For A Periodic Waveform With Uncertain Frequency And Waveform Shape, And Data Dropouts, Justin Saboury

Theses and Dissertations

Gait analysis presents the challenge of detecting a periodic waveform in the presence of time varying frequency, amplitude, DC offset, and waveform shape, with acquisition gaps from partial occlusions. The combination of all of these components presents a formidable challenge. The Extended Kalman Filter for this system model has six states, which makes it weakly identifiable within the standard Extended Kalman Filter network. In this work, a novel robust Extended Kalman Filter-based approach is presented and evaluated for clinical use in gait analysis. The novel aspect of the proposed method is that at each sample, the present and several past …

A Fault-Tolerant Control Strategy For Three-Level Neutral-Point Clamped (Npc) Inverter, Weijun Zhu

Theses and Dissertations

When the open-circuit fault occurs on neutral-point clamped (NPC) inverters, it can cause the distortion of output currents, excessively large fluctuation of output voltages, and unbalanced neutral-point potential. Currently, several existing fault diagnosis methods are able to identify the fault types, but they are unable to identify the switching devices where the open-circuit faults occur. Furthermore, even if the open-circuit faults can be identified, the implications caused by open-circuit faults need to be further addressed. This thesis is focused on diagnosing the open-circuit faults and mitigating the problems caused by these faults.

An effective fault diagnosis method is proposed in …

Financially Motivated Lmp Manipulation By Aggregators In Power Markets, Chaoyi Chen

Theses and Dissertations

Renewable energy accounts for a sizeable share within modern power systems and aggregators of renewable generators play an important role in the electricity market. However, because renewable generators produce power intermittently, it is hard to monitor and supervise the behavior of the aggregators. There is a chance for aggregators to manipulate the locational marginal prices (LMPs) in the power market by curtailing generation in order to increase their profits.

In this thesis we propose a tri-level model that can quantify aggregators’ potential profits. This model is based on both a real-time optimal dispatch and an LMP clearing procedure. With this …

Model Augmented Deep Neural Networks For Medical Image Reconstruction Problems, Hongquan Zuo

Theses and Dissertations

Solving an ill-posed inverse problem is difficult because it doesn't have a unique solution. In practice, for some important inverse problems, the conventional methods, e.g. ordinary least squares and iterative methods, cannot provide a good estimate. For example, for single image super-resolution and CT reconstruction, the results of these conventional methods cannot satisfy the requirements of these applications. While having more computational resources and high-quality data, researchers try to use machine-learning-based methods, especially deep learning to solve these ill-posed problems. In this dissertation, a model augmented recursive neural network is proposed as a general inverse problem method to solve these …

High Frequency Constraints On The Layout Of Wide Band Gap-Based Power Electronic Assemblies Within Shielded Enclosures, Jonathan Hajime Itokazu

Theses and Dissertations

Since its integration into power electronic converters, the value proposition of wide band

gap semiconductors has yet to be holistically realized due to the high frequency effects associated with increased switching speeds. The United States Navy’s Smart Ship System

Design (S3D) platform enables the investigation of wide band gap-based devices in shipboard Medium Voltage Direct Current (MVDC) Integrated Power and Energy Systems

(IPES) through the use of metaheuristic model-based scaling laws. These physics-based

scaling laws are produced from a virtual prototyping approach which takes into account the

discrete building blocks associated with multi-cell based power conversion and distribution

equipment and …

Tuning Size And Light Emission Characteristics Of Cdses/Zns Alloyed Core-Shell Quantum Dots By Alcohol, John Casey Marnocha

Theses and Dissertations

In this thesis, a one-step isotropic down-tuning of the size of alloyed CdSe1−xSx/ZnS core- shell quantum dots is developed by vapor and liquid-phase etching using a ∼ 10 : 1 isopropyl alcohol to water solution. The results of spectroscopic studies confirm continuous variation of the excitonic emission color from red to green for samples treated for up to 15 mins using a vapor-based method. According to HRTEM characterizations, the shift is consistent with a diameter reduction of quantum dots that proceeds at the average rate of ∼ 1.3 ̊A/min. The emission intensity while seen to undergo an initial drop due …

Model Predictive Control For Mitigating Sensor Attacks On Multilevel Inverters, Rao Rao

Theses and Dissertations

Nowadays, multilevel power inverters have become a hot research topic which are being widely used in smart grids. They are also driving devices for conveyors, compressors, motors, and can enable uninterruptible power supply for critical loads such as database centers or telecommunications base stations. In the future, smart grids will play an important role to achieve higher efficiency, smarter control and better performance. Such an ambitious goal can only be achieved by inverters with higher voltage and power levels.

The smart grids are the typical cyber-physical systems that is composed of physical processes and computation units combined by sensors, actuators, …

Fault Diagnosis Of Hvdc Systems Using Machine Learning Based Methods, Yu Chen

Theses and Dissertations

With the development of high-power electronic technology, HVDC system is applied in the power system because of advantages in large-capacity and long-distance transmission, stability, and flexibility. Therefore, as the guarantee of reliable operating of HVDC system, fault diagnosis of the HVDC system is of great significance. In the current variety methods used in fault diagnosis, Machine Learning based methods have become a hotspot. To this end, the performance of several commonly used machine learning classifiers is compared in HVDC system. First of all, nine faults both in AC systems and DC systems of the HVDC system are set in the …

A State Evaluation Method For Solder Layer In Mosfet, Zhenyu Deng

Theses and Dissertations

MOSFET is the core component in power equipment. It is widely used in electrical vehicles (EV), wind generation, rail transit and so on. The long-term impact of temperature and stress cause fatigue in the device during operation. Because of the low melting point of 96.5Sn3.5Ag, solder layer aging and failure is one of the main failure modes. So, it is important to figure out the failure mechanism and the effects of defects in the solder layer.

A finite element (FE) model considered the temperature dependence of materials was built in COMSOL software to support the subsequent studies. Effects of voids …

High Frequency Constraints On The Layout Of Wide Band Gap-Based Power Electronic Assemblies Within Shielded Enclosures, Jonathan Hajime Itokazu

Theses and Dissertations

Since its integration into power electronic converters, the value proposition of wide band

gap semiconductors has yet to be holistically realized due to the high frequency effects associated with increased switching speeds. The United States Navy’s Smart Ship System

Design (S3D) platform enables the investigation of wide band gap-based devices in shipboard Medium Voltage Direct Current (MVDC) Integrated Power and Energy Systems

(IPES) through the use of metaheuristic model-based scaling laws. These physics-based

scaling laws are produced from a virtual prototyping approach which takes into account the

discrete building blocks associated with multi-cell based power conversion and distribution

equipment and …

Model Predictive Control For Mitigating Sensor Attacks On Multilevel Inverters, Rao Rao

Theses and Dissertations

Nowadays, multilevel power inverters have become a hot research topic which are being widely used in smart grids. They are also driving devices for conveyors, compressors, motors, and can enable uninterruptible power supply for critical loads such as database centers or telecommunications base stations. In the future, smart grids will play an important role to achieve higher efficiency, smarter control and better performance. Such an ambitious goal can only be achieved by inverters with higher voltage and power levels.

The smart grids are the typical cyber-physical systems that is composed of physical processes and computation units combined by sensors, actuators, …

Integration Of Preventive And Emergency Responses To Boost Distribution System Resilience, Gang Wang

Theses and Dissertations

Recent years have seen a series of large-scale blackouts due to extreme weather events around the world. These high impact, lower probability events have caused great economic losses to modern society. Therefore, it is urgent to study the resilience improvement measures of power systems to mitigate the effects of adverse extreme events. Current research mainly focuses on the hardening measures where robust optimization is used to solve the problems. However, due to the consideration of worst case of uncertain parameters, the robust optimization method is usually too conservative and uneconomical in many situations.

In this thesis, operational measures are deployed …

Wavelet Transform Based Methods For Fault Detection And Diagnosis Of Hvdc Transmission Systems, Zhongxuan Li

Theses and Dissertations

ABSTRACT

WAVELET TRANSFORM BASED METHODS FOR FAULT DETECTION AND DIAGNOSIS OF HVDC TRANSMISSION SYSTEMS

by

Zhonxguan Li

The University of Wisconsin-Milwaukee, 2019

Under the Supervision of Professor Lingfeng Wang

High-voltage direct current (HVDC) is a key enabler in power system. HVDC offers a most efficient means of transmitting large amount of power. Applications of HVDC can improve the operation security, reliability performance and economy of power systems. Due to factors inside and outside the HVDC system, the system will experience various faults, which have infected HVDC system. VSC-HVDC is a HVDC transmission based on IGBT and PWM. VSC-HVDC direct current …

Novel Non-Invasive Technology For The Detection Of Thin Biofilm In Piping Systems (Phase - 1), Sachin Davis

Theses and Dissertations

Biofilms are formed when a group of cells of microorganisms stick to each other and often on a surface. The development of biofilm has been a major issue in many fields (medical field, food, chemical, and water industry are a few such fields). In the medical field alone, biofilm infections have reportedly cost over five billion USD in additional healthcare expenses. The food industry usually halts the operation of its plant eight hours, every day to ensure that their equipment and transportation channels are clean and free from any biofilm presence. Similarly, the water and chemical industry need to ensure …

Derivation Of Power System Module Metamodels For Early Shipboard Design Explorations, Rounak Siddaiah

Theses and Dissertations

The U.S. Navy is currently challenged to develop new ship designs under compressed schedules.

These ship designs must necessarily incorporate emerging technologies for high power energy

conversion in order to enable smaller ship designs with a high degree of electrification and

next generation electrified weapons. One way this challenge is being addressed is through development

of collaborative concurrent design environment that allows for design space exploration

across a wide range of implementation options. The most significant challenge is assurance of

a dependable power and energy service via the shipboard Integrated Power and Energy System

(IPES). The IPES is largely made …

Epon Communication Network Topology Planning Based On Node Importance Of Active Distribution Network, Yingqiao He

Theses and Dissertations

A large amount of DGs (distributed generations) and distributed resources accessing to distribution network is a characteristic of present distribution network. So the concept of the active distribution network is proposed, which is a new form of distribution network with flexible power network structure and active control and management with high permeability of DGs in the distribution network. According to the actual operation state of power system, active distribution network actively manages the massive distributed power supply and adaptively adjusts the network to satisfy the requirements of economy and security power supply.

This thesis aims to propose a feasible optimization …

Tuning Size And Light Emission Characteristics Of Cdses/Zns Alloyed Core-Shell Quantum Dots By Alcohol, John Casey Marnocha

Theses and Dissertations

In this thesis, a one-step isotropic down-tuning of the size of alloyed CdSe1−xSx/ZnS core- shell quantum dots is developed by vapor and liquid-phase etching using a ∼ 10 : 1 isopropyl alcohol to water solution. The results of spectroscopic studies confirm continuous variation of the excitonic emission color from red to green for samples treated for up to 15 mins using a vapor-based method. According to HRTEM characterizations, the shift is consistent with a diameter reduction of quantum dots that proceeds at the average rate of ∼ 1.3 ̊A/min. The emission intensity while seen to undergo an initial drop due …

A Viable Residential Dc Microgrid For Low Income Communities – Architecture, Protection And Education, Karthik Palaniappan

Theses and Dissertations

The availability of fossil fuels in the future and the environmental effects such as the carbon footprint of the existing methodologies to produce electricity is an increasing area of concern. In rural areas of under-developed parts of the world, the problem is lack of access to electrification. DC microgrids have become a proven solution to electrification in these areas with demonstrated exceptional quality of power, high reliability, efficiency, and simplified integration between renewable energy sources (principally solar PV) and energy storage. In the United States, a different problem occurs that can be addressed with the same DC microgrid approach that …

Wavelet Transform Based Methods For Fault Detection And Diagnosis Of Hvdc Transmission Systems, Zhongxuan Li

Theses and Dissertations

ABSTRACT

WAVELET TRANSFORM BASED METHODS FOR FAULT DETECTION AND DIAGNOSIS OF HVDC TRANSMISSION SYSTEMS

by

Zhonxguan Li

The University of Wisconsin-Milwaukee, 2019

Under the Supervision of Professor Lingfeng Wang

High-voltage direct current (HVDC) is a key enabler in power system. HVDC offers a most efficient means of transmitting large amount of power. Applications of HVDC can improve the operation security, reliability performance and economy of power systems. Due to factors inside and outside the HVDC system, the system will experience various faults, which have infected HVDC system. VSC-HVDC is a HVDC transmission based on IGBT and PWM. VSC-HVDC direct current …

A State Evaluation Method For Solder Layer In Mosfet, Zhenyu Deng

Theses and Dissertations

MOSFET is the core component in power equipment. It is widely used in electrical vehicles (EV), wind generation, rail transit and so on. The long-term impact of temperature and stress cause fatigue in the device during operation. Because of the low melting point of 96.5Sn3.5Ag, solder layer aging and failure is one of the main failure modes. So, it is important to figure out the failure mechanism and the effects of defects in the solder layer.

A finite element (FE) model considered the temperature dependence of materials was built in COMSOL software to support the subsequent studies. Effects of voids …

Internal Fault Diagnosis Of Mmc-Hvdc Based On Classification Algorithms In Machine Learning, Tianyi Jin

Theses and Dissertations

With the development of the HVDC system, MMC-HVDC is now the most advanced technology that has been put into use. In power systems, faults happen during the operation due to natural reasons or devices physical issues, which would cause serious economic losses and other implications. Thus, fault detection and analysis are extremely important, especially in the HVDC system. Existing works in literature mainly focus on the faults detection and analysis on the system side such as short circuit of the AC side, and open circuit of the DC side. However, little attention has been paid to the fault detection and …

Integration Of Preventive And Emergency Responses To Boost Distribution System Resilience, Gang Wang

Theses and Dissertations

Recent years have seen a series of large-scale blackouts due to extreme weather events around the world. These high impact, lower probability events have caused great economic losses to modern society. Therefore, it is urgent to study the resilience improvement measures of power systems to mitigate the effects of adverse extreme events. Current research mainly focuses on the hardening measures where robust optimization is used to solve the problems. However, due to the consideration of worst case of uncertain parameters, the robust optimization method is usually too conservative and uneconomical in many situations.

In this thesis, operational measures are deployed …