Engineering Commons^™

Power Optimization Of Solar Powered Standalone Wireless Sensor System, Rajan Amatya

Masters Theses

Wireless sensor systems are common in applications where harsh environmental conditions or remote locations make it difficult to run wires. Having these sensor systems self-powered is essential as it is difficult for battery replacement. Using solar as an alternative source of energy can be a medium to charge the battery in such scenarios. With an increasing number of portable devices powered by battery; more and more research is focused on low-power design technique. For this thesis, a microcontroller (Texas Instruments MSP432) was used along with a digital sensor (Bosch BME280) to provide temperature, pressure and humidity information, and Wi-Fi module …

Stereotypic Repetitive Hand Flapping Movement Detector Children With Autism, Subodh Ashok Bansode

Masters Theses

The prevalence of Autism Spectrum Disorder (ASD) has increased at a significant rate in recent years, especially in developed nations such as the United States, Japan, and South Korea. Extensive research is being carried out to study the behavioral characteristics of the disease. Children affected with autism tend to exhibit a spectrum of symptoms depending on the severity of the disease. These behaviors are primarily repetitive, self-stimulatory, and stereotypic behaviors such as hand flapping (i.e., repeatedly shaking their hands), body rocking (i.e., swaying their body back and forth), drumming, walking around in a confined space, and walking with shortened steps …

On-Chip Communication And Security In Fpgas, Shivukumar Basanagouda Patil

Masters Theses

Innovations in Field Programmable Gate Array (FPGA) manufacturing processes and architectural design have led to the development of extremely large FPGAs. There has also been a widespread adaptation of these large FPGAs in cloud infrastructures and data centers to accelerate search and machine learning applications. Two important topics related to FPGAs are addressed in this work: on-chip communication and security. On-chip communication is quickly becoming a bottleneck in to- day’s large multi-million gate FPGAs. Hard Networks-on-Chip (NoC), made of fixed silicon, have been shown to provide low power, high speed, flexible on-chip communication. An iterative algorithm for routing pre-scheduled time-division-multiplexed …

Crowdsourcing Based Micro Navigation System For Visually Impaired, Quan Shi

Masters Theses

Mobility and safety are primary concerns for blind and visually impaired (BVI) users when navigating in unfamiliar environments. Typically, a sighted person can locate a place of interest if they are provided guidance while approaching within a few meters of the location. However, this resolution of guidance is often insufficient for blind travelers. In this thesis, we propose a crowdsourcing based micro navigation system for BVI users in both indoor and outdoor environments. To achieve this goal, our system includes three parts: crowdsourcing reports generated by volunteers using the volunteer application, landmarks validation performed by the system administrator using the …

Application And Evaluation Of Lighthouse Technology For Precision Motion Capture, Soumitra Sitole

Masters Theses

This thesis presents the development towards a system that can capture and quantify motion for applications in biomechanical and medical fields demanding precision motion tracking using the lighthouse technology. Commercially known as SteamVR tracking, the lighthouse technology is a motion tracking system developed for virtual reality applications that makes use of patterned infrared light sources to highlight trackers (objects embedded with photodiodes) to obtain their pose or spatial position and orientation. Current motion capture systems such as the camera-based motion capture are expensive and not readily available outside of research labs. This thesis provides a case for low-cost motion capture …

Skinnysensor: Enabling Battery-Less Wearable Sensors Via Intrabody Power Transfer, Neev Kiran

Masters Theses

Tremendousadvancement inultra-low powerelectronics and radiocommunica tionshas significantly contributed towards the fabrication of miniaturized biomedical sensors capable of capturing physiological data and transmitting them wirelessly. However, most of the wearable sensors require a battery for their operation. The battery serves as one of the critical bottlenecks to the development of novel wearable applications, as the limitations offered by batteries are affecting the development of new form-factors and longevity of wearable devices. In this work, we introduce a novel concept, namely Intra-Body Power Transfer (IBPT), to alleviate the limitations and problems associated with batteries, and enable wireless, batteryless wearable devices. The innovation …

On Wlan Fingerprint Indoor Positioning Systems Clustering, And Classification For Enhanced Performance, Haider G. Al Glehawi

Masters Theses

The most economic and affordable IPS are those incorporating existing infrastructure, such as the widely spread Wireless Local Area Network (WLAN). The Received Signal Strength (RSS) fingerprinting-based system is one of the most promising and powerful techniques so far to be used for indoor positioning. However, there are two challenges in using RSS based IPS; the first challenge is the variation of RSS to indoor multipath propagation, and the second is the high number of Access Points (APs) that are deployed in the region of interest. The first issue leads to degradation in the performance of RSS based IPS, while …

A Study On Modelling Spatial-Temporal Human Mobility Patterns For Improving Personalized Weather Warning, Yue Xu

Masters Theses

Understanding human mobility patterns is important for severe weather warning since these patterns can help identify where people are in time and in space when flash floods, tornados, high winds and hurricanes are occurring or are predicted to occur. A GIS (Geographic Information Science) data model was proposed to describe the spatial-temporal human activity. Based on this model, a metric was designed to represent the spatial-temporal activity intensity of human mobility, and an index was generated to quantitatively describe the change in human activities. By analyzing high-resolution human mobility data, the paper verified that human daily mobility patterns could be …

Improvements To The Umass S-Band Fm-Cw Vertical Wind Profiling Radar: System Performance And Data Analysis., Joseph Waldinger

Masters Theses

Upgrades to the University of Massachusetts S-Band FMCW boundary layer vertical wind profiling radar for use in the VORTEX-Southeast campaign are discussed. During the experiment, the radar characterizes velocity and reflectivity in clear-air and light to moderate precipitation conditions. Data is presented from the experiment which illustrates system performance and typical environmental results. This thesis begins with relevant background information on FM-CW radar operation, scattering mechanisms, and other calculations relevant to results discussed. The system hardware is described, along with improvements and modifications made prior to and during the experiment. Collected data is used to demonstrate system capabilities, improvements made, …

An Evaluation Of Sdn And Nfv Support For Parallel, Alternative Protocol Stack Operations In Future Internets, Bhushan Suresh

Masters Theses

Virtualization on top of high-performance servers has enabled the virtualization of network functions like caching, deep packet inspection, etc. Such Network Function Virtualization (NFV) is used to dynamically adapt to changes in network traffic and application popularity. We demonstrate how the combination of Software Defined Networking (SDN) and NFV can support the parallel operation of different Internet architectures on top of the same physical hardware. We introduce our architecture for this approach in an actual test setup, using CloudLab resources. We start of our evaluation in a small setup where we evaluate the feasibility of the SDN and NFV architecture …

Mgsnn2: A New Eco-Friendly Wide Band Gap Semiconductor, Krystal R. York

Masters Theses

Materials having a wide band gap (above 2 eV) can provide new alternatives for existing light-emitting diodes (LEDs) and other opto-electronic devices. Currently, many such devices are comprised of low-earth-abundant elements, such as gallium and indium, which are harmful to the environment to extract and difficult to recycle. Alternatively, MgSnN2 is an unexplored material comprised of earth abundant elements which benefit from a mature recycling infrastructure. This material has a predicted band gap of 3.43 eV, indicating that it could be a viable substitute for GaN (band gap of 3.4 eV), which is commonly used in LEDs and other device …

Applications Of Physical Unclonable Functions On Asics And Fpgas, Mohammad Usmani

Masters Theses

With the ever-increasing demand for security in embedded systems and wireless sensor networks, we require integrating security primitives for authentication in these devices. One such primitive is known as a Physically Unclonable Function. This entity can be used to provide security at a low cost, as the key or digital signature can be generated by dedicating a small part of the silicon die to these primitives which produces a fingerprint unique to each device. This fingerprint produced by a PUF is called its response. The response of PUFs depends upon the process variation that occurs during the manufacturing process. In …

Fusion Of Audio And Visual Information For Implementing Improved Speech Recognition System, Vikrant Satish Acharya

Masters Theses

Speech recognition is a very useful technology because of its potential to develop applications, which are suitable for various needs of users. This research is an attempt to enhance the performance of a speech recognition system by combining the visual features (lip movement) with audio features. The results were calculated using utterances of numerals collected from participants inclusive of both male and female genders. Discrete Cosine Transform (DCT) coefficients were used for computing visual features and Mel Frequency Cepstral Coefficients (MFCC) were used for computing audio features. The classification was then carried out using Support Vector Machine (SVM). The results …

Analog Computing Using 1t1r Crossbar Arrays, Yunning Li

Masters Theses

Memristor is a novel passive electronic device and a promising candidate for new generation non-volatile memory and analog computing. Analog computing based on memristors has been explored in this study. Due to the lack of commercial electrical testing instruments for those emerging devices and crossbar arrays, we have designed and built testing circuits to implement analog and parallel computing operations. With the setup developed in this study, we have successfully demonstrated image processing functions utilizing large memristor crossbar arrays. We further designed and experimentally demonstrated the first memristor based field programmable analog array (FPAA), which was successfully configured for audio …

Immersive Pre-Travel Training Application For Seniors And People With Disabilities, Yang Li

Masters Theses

The ability to travel independently by using public transportation is important to everyone. However, that is a very difficult task for seniors and people with disabilities since it may cause anxiety when they use unfamiliar transportation venues. Therefore, many seniors and people with disabilities use paratransit services instead of public transportation such as the subway and buses. However, the cost of paratransit services is prohibitive and growing due to the increase in the number of seniors and people with disabilities.

This master thesis project presents an immersive pre-travel training application for seniors and people with disabilities. It will help them …

A Novel Power Integrity Modeling Method Based On Plane Pair Peec, Siqi Bai

Masters Theses

"A low impedance power distribution network (PDN) is essential for high frequency integrated circuits. A novel modeling mothed, i.e. the plane pair PEEC method is proposed in this thesis to model the PDN of the multi-layered printed circuit board. The modeling results agrees favorably with full wave simulation and measurement. A PDN tool is develop based on this method"--Abstract, page iii.

Generalized Adaptive Variable Bit Truncation Model For Approximate Stochastic Computing, Keerthana Pamidimukkala

Masters Theses

"Stochastic computing as a computing paradigm is currently undergoing revival as the advancements in technology make it applicable especially in the wake of the need for higher computing power for emerging applications. Recent research in stochastic computing exploits the benefits of approximate computing, called Approximate Stochastic Computing (ASC), which further reduces the operational overhead in implementing stochastic circuits. A mathematical model is proposed to analyze the efficiency and error involved in ASC. Using this mathematical model, a new generalized adaptive method improving on ASC is proposed in the current thesis. The proposed method has been discussed with two possible implementation …

Coaxial Cable Ring Resonator Based On Pair Sided Coaxial Cable Bragg Grating Coupler For Sensing Appllication, Xiaotong Tang

Masters Theses

“Coaxial cable based devices, such as coaxial cable Bragg grating (CCBG), coiled coaxial cable resonator have been demonstrated for sensing applications to address the challenges faced by fiber optic sensors (e.g., large strain survivability, installation). Inspired by the fiber ring resonator (FRR), coaxial cable based ring resonator (CCRR) is reported in this thesis. The device mainly formed by a homemade coaxial cable Bragg grating (CCBG) pair based side coupler. Comparing to the commercial coupler, CCBG-SC improves the flexibility of the device for sensing applications. The coupling frequency of the CCBG-based coupler can be modified by changing the grating length and …

Modeling And Control Of Three-Phase Grid-Connected Pv Inverters In The Presence Of Grid Faults, Paresh Vinubhai Patel

Masters Theses

"A two-stage photovoltaic grid-connected microgrid modeling approach is presented in this work. The purpose of the modeling is the behavior study of the microgrid during the low-voltage event on the grid. A complete mathematical model is discussed for each component of the system. The MPPT of the photovoltaic system is integrated with the boost controller to inject the constant current in the DC-link. The boost converter and the inverter control is implemented using the cascaded PI control. A dual second-order generalized integrator (DSOGI) method is implemented for the sequence extraction. The inverter controller is designed to meet the grid-code requirement …

Practical Dwell Times For Switched System Stability With Smart Grid Application, William Roy St. Pierre

Masters Theses

"Switched systems are encountered throughout many engineering disciplines, but confirming their stability is a challenging task. Even if each subsystem is asymptotically stable, certain switching sequences may exist that drive the overall system states into unacceptable regions. This thesis contains a process that grants stability under switching to switched systems with multiple operating points. The method linearizes a switched system about its distinct operating points, and employs multiple Lyapunov functions to produce modal dwell times that yield stability. This approach prioritizes practicality and is designed to be useful for large systems with many states and subsystems due to its ease …

Battery Optimization In Microgrids Using Markov Decision Process Integrated With Load And Solar Forecasting, Prateek Jain

Masters Theses

"Rising climatic concerns call for unconventional/renewable energy sources which reduce the carbon footprint. Microgrids that integrate a variety of renewable energy resources play a key role in utilizing these energy resources in a more efficient and environmentally friendly manner. Battery systems effectively help to utilize these energy resources more efficiently. This research work presents a framework based on Markov Decision Process (MDP) integrated with load and solar forecasting to derive an optimal charging/discharging action of Battery with rolling horizon implementation. The load forecasting regression models are discussed and developed. Also, various solar forecasting models like clear sky, multi-regression and Non-Linear …

System Level Power Integrity Transient Analysis Using A Physics-Based Approach, Jun Xu

Masters Theses

"With decreasing supply voltage level and massive demanding current on system chipset, power integrity design becomes more and more critical for system stability. The ultimate goal of well-designed power delivery network (PDN) is to deliver desired voltage level from the source to destination, in other words, to minimize voltage noise delivered to digital devices. The thesis is composed of three parts. The first part focuses on-die level power models including simplified chip power model (CPM) for system level analysis and the worst scenario current profile. The second part of this work introduces the physics-based equivalent circuit model to simplify the …

De-Embedding Method Comparisons And Physics Based Circuit Model For High Frequency D-Probe, Yuan Chen

Masters Theses

"In section 1, the procedures of 1X-Reflect smart fixture de-embedding (SFD), 1-port auto fixture removal (AFR), and 2X-Thru SFD are compared from various perspectives: test fixture design, the de-embedding procedure, and de-embedded results. The accuracy of fixture characterization and the de-embedded result is the key figure of merit (FOM) in each de-embedding method. Full wave models are built to evaluate the FOM of the three methods, by comparing the scattering parameters (S-parameters) and time domain reflectometer (TDR). A test coupon for measuring USB-C cables is adopted to serve as a manufactured validation purpose.

In section 2, a physics-based circuit model …

Multi-Objective Optimal Battery Placement In Distribution Networks, Kiana Khalilnejad

Masters Theses

"Due to high penetration of renewable energy resources in today's electricity generation, considerable voltage fluctuations are witnessed in power systems. As an attempt to solve this issue, in this study, multi-objective optimal placement and sizing of distribution-level battery storage system is performed using semidefinite programing. Placement of one or multiple battery system is studied under various objectives including the cost, voltage regulation, reactive power dispatch, renewable resource curtailment, and minimum network power losses. Power flow equations are solved in the form of semidefinite constraints and the rank constraint is ignored. Additionally, combination of these objectives to form a multi-objective problem …

Methodology For 3d Full-Wave Simulation Of Electrostatic Breakdown Across An Air Gap, Darwin Zhang Li

Masters Theses

"The Rompe-Weizel SPICE model is used to obtain the time dependent arc resistance during simulation of air gap discharge. The SPICE model is solved using a circuit simulator, and the accompanying 3D model is solved using the transmission-line matrix time domain numerical method. Transient co-simulation is a new technique that is used to solve both circuit and 3D models at the same time. Transient co-simulation with the Rompe-Weizel SPICE model is first validated for different arc lengths using a simple geometry of a rod discharging to a ground plane. Validation is achieved by comparing the discharge currents from simulation with …

Lyapunov Stability Analysis Of Switched Microgrid Systems, Bokang Zhou

Masters Theses

"In this thesis, a Lyapunov-based method for analyzing the stability of a switched microgrid system is proposed. First, a small second-order system is explored as example to demonstrate the effectiveness of switching patterns on the stability of a system switching among different respectively stable operating points. Lyapunov function is employed in order to determine the proper state-based switching conditions under which global stability is guaranteed, or under which the system is driven unstable. Then, a linearized statespace model of a looped seven-node microgrid is established. Solid-state transformers (SSTs), distributed energy storage devices and synchronous generators are introduced and modeled in …

Embedded Fiber Optic Sensors For Temperature Monitoring Of Continuous Casting Mold, Yiyang Zhuang

Masters Theses

"The continuous casting process has been widely used for most of the steel production in the world instead of conventional ingot casting/rolling. Traditionally, thermocouples are being widely used to monitor the mold temperature in the continuous casting which has the following drawbacks: large size, low spatial resolution, and single detection point. On the contrary, fiber optic sensors can be a promising solution to the continuous casting temperature monitoring owing to its advantage of compact size, high resolution, high-temperature survivability, etc.

In this thesis, we successfully developed extrinsic Fabry-Perot interferometer (EFPI) sensor for point temperature sensing, and optical frequency domain reflectometry …

A Hybrid Cavity And Parallel-Plate Peec Method For Analysis Of Complex Power Net Area Fills, And A Tool Development For Peak Distortion Analysis, Chenxi Huang

Masters Theses

"Modern ASICs and FPGAs are becoming more and more dense, which is causing an increasing demand of the current draw from the power distribution network (PDN). And one of the main design objectives of a power distribution network is to reduce the voltage noise ripple below a specified allowable limit. Although the target impedance is a commonly used criterion in most PDN designs, it may not be efficient because it's usually rather pessimistic. Herein a time domain voltage ripple decomposition approach is proposed to avoid overdesign as well as provide design guidance to PI engineers. Based on a physics-based circuit …

Developing A Methodology For Estimating The Growth Of Radiated Emission From Multi-Modular Systems, Kaustav Ghosh

Masters Theses

"The large multiscale problems are commonly faced in real-world applications such as analysis of electromagnetic interference for a printed circuit board installed on a large platform with connected cables, wires and other high speed interfaces. EMI problems are not uncommon in high speed systems which involve multiple modules of complex hardware. As the system clock frequency and data rate increases, so does the challenges in controlling the EMI in such systems. The costs to prototype and to develop networking equipment are growing as a result of increasing complexities and densities. EMC regulations require radiated emission testing to be done in …

Analysis And Mitigation Of Parallel-Plate Noise For High-Isolation Applications, Zachary Joel Legenzoff

Masters Theses

"Achieving highs levels of isolation between different functionalities in a PCB can be challenging. One of the major issues is that vertically adjacent planes or area fills in a PCB can form a parallel-plate waveguide with no cutoff frequency and serve as an efficient coupling mechanism between interconnects. Due to the finite size of the conductors, reflections off the edges of these parallel-plate cavities can result in the formation of standing-wave patterns with very high field strengths, resulting in high coupling at certain frequencies. This noise coupling mechanism can be suppressed by connecting the parallel plates together with an adequate …