Engineering Commons^™

Optimal Basis For Ultrasound Rf Apertures: Applications To Real-Time Compression And Beamforming, Sharmin Kibria

Masters Theses 1911 - February 2014

Modern medical ultrasound machines produce enormous amounts of data, as much as several gigabytes/sec in some systems. The challenges of generating, storing, processing and reproducing such voluminous data has motivated researchers to search for a feasible compression scheme for the received ultrasound radio frequency (RF) signals. Most of this work has concentrated on the digitized data available after sampling and A/D conversion. We are interested in the possibility of compression implemented directly on the received analog RF signals; hence, we focus on compression of the set of signals in a single receive aperture. We first investigate the model-free approaches to …

Free Wake Potential Flow Vortex Wind Turbine Modeling: Advances In Parallel Processing And Integration Of Ground Effects, Nathaniel B. Develder

Masters Theses 1911 - February 2014

Potential flow simulations are a great engineering type, middle-ground approach to modeling complex aerodynamic systems, but quickly become computationally unwieldy for large domains. An N-body problem with N-squared interactions to calculate, this free wake vortex model of a wind turbine is well suited to parallel computation. This thesis discusses general trends in wind turbine modeling, a potential flow model of the rotor of the NREL 5MW reference turbine, various forms of parallel computing, current GPU hardware, and the application of ground effects to the model. In the vicinity of 200,000 points, current GPU hardware was found to be nearly 17 …

Post Hoc Indoor Localization Based On Rss Fingerprint In Wlan, Hao Huang

Masters Theses 1911 - February 2014

In the investigation of crimes committed by wireless users, one of the key goals is to determine the location of the mobile device at the time of the crime. Since this happens during the investigative phase after the crime is committed, we term this the post hoc geographical localization estimation problem. In this thesis, we introduce the post hoc geographical localization estimation problem and present approaches for its solution based on radio frequency (RF) fingerprinting. Motivated by the goal of establishing a crime's location with enough accuracy to obtain a search warrant, our focus is on locating a criminal mobile …

Compressive Parameter Estimation With Emd, Dian Mo

Masters Theses 1911 - February 2014

In recent years, sparsity and compressive sensing have attracted significant attention in parameter estimation tasks, including frequency estimation, delay estimation, and localization. Parametric dictionaries collect signals for a sampling of the parameter space and can yield sparse representations for the signals of interest when the sampling is sufficiently dense. While this dense sampling can lead to high coherence in the dictionary, it is possible to leverage structured sparsity models to prevent highly coherent dictionary elements from appearing simultaneously in a signal representation, alleviating these coherence issues. However, the resulting approaches depend heavily on a careful setting of the maximum allowable …

Towards Accessible, Usable Knowledge Frameworks In Engineering, Jeffrey Mcpherson

Masters Theses 1911 - February 2014

A substantial amount of research has been done in the field of engineering knowledge management, where countless ontologies have been developed for various applications within the engineering community. However, despite the success shown in these research efforts, the techniques have not been adopted by industry. This research aims to uncover the reasons for the slow adoption of engineering knowledge frameworks, namely ontologies, in industry.

There are two projects covered in this thesis. The first project is the development of a cross-domain ontology for the Biomesh Project, which spans the fields of mechanical engineering, biology, and anthropology. The biology community is …

Resource Allocation And Pricing In Virtual Wireless Networks, Xin Chen

Masters Theses 1911 - February 2014

The Internet architecture has proven its success by completely changing people’s lives. However, making significant architecture improvements has become extremely difficult since it requires competing Internet Service Providers to jointly agree. Re- cently, network virtualization has attracted the attention of many researchers as a solution to this ossification problem. A network virtualization environment allows multiple network architectures to coexist on a shared physical resource. However, most previous research has focused on network virtualization in a wired network en- vironment. It is well known that wireless networks have become one of the main access technologies. Due to the probabilistic nature of …

Bi-Directional Vector Variable Gain Amplifier For An X-Band Phased Array Radar Application, Arash Mashayekhi

Masters Theses 1911 - February 2014

This thesis presents the design, layout, and measurements of a bi-directional amplifier with variable vector (in-phase / quadrature) gain control that will be part of an electronically steered phased array system. The electronically steered phased array has many advantages over the conventional mechanically steered antennas including rapid scanning of the beam and adaptively creating nulls in desired locations. The 10-bit bi-directional Vector Variable Gain Amplifier (VVGA) is part of the transmit and receive module of each antenna element where transmit and receive functionality is determined through a simple switch. The VVGA performs amplification of the IF IQ pair by an …

Integration And Measurements Of A Ka-Band Interferometric Radar In An Airborne Platform, Rockwell B. Schrock

Masters Theses 1911 - February 2014

The Topographic Interferometry Mapping Mission (TIMMi) instrument is a unique millimeter wave interferometric radar system operating at 35 GHz (Ka-band). It was constructed in part to advance the technology readiness level of NASA’s Surface Water and Ocean Topography (SWOT) mission, a spaceborne platform that will globally map the altimetry of Earth’s water to gain insight into surface water interactions and dynamics. Previous ground deployments of TIMMi were successful in demonstrating the abilities of the system from a stationary platform. The next logical step was to move TIMMi closer to space by installing it on an airborne platform prove its capability …

Testing And Validation Of A Prototype Gpgpu Design For Fpgas, Murtaza Merchant

Masters Theses 1911 - February 2014

Due to their suitability for highly parallel and pipelined computation, field programmable gate arrays (FPGAs) and general-purpose graphics processing units (GPGPUs) have emerged as top contenders for hardware acceleration of high-performance computing applications. FPGAs are highly specialized devices that can be customized to a specific application, whereas GPGPUs are made of a fixed array of multiprocessors with a rigid architectural model. To alleviate this rigidity as well as to combine some other benefits of the two platforms, it is desirable to explore the implementation of a flexible GPGPU (soft GPGPU) using the reconfigurable fabric found in an FPGA. This thesis …

Application Of Finite Element Method In Protein Normal Mode Analysis, Chiung-Fang Hsu

Masters Theses 1911 - February 2014

This study proposed a finite element procedure for protein normal mode analysis (NMA). The finite element model adopted the protein solvent-excluded surface to generate a homogeneous and isotropic volume. A simplified triangular approximation of coarse molecular surface was generated from the original surface model by using the Gaussian-based blurring technique. Similar to the widely adopted elastic network model, the finite element model holds a major advantage over standard all-atom normal mode analysis: the computationally expensive process of energy minimization that may distort the initial protein structure has been eliminated. This modification significantly increases the efficiency of normal mode analysis. In …

Effects Of Different Methods Of Aggregation Of Probabilities On The R&D Investment Portfolio For Optimal Emissions Abatement: An Empirical Evaluation, Olaitan P. Olaleye

Masters Theses 1911 - February 2014

This thesis examines two possible orders of combining multiple experts in elicitations with multiple de-composed events: Should experts be combined early or later in the decision process? This thesis is in conjunction with the paper (Baker & Olaleye, 2012) where we show that it is best to combine experts early as later combination leads to a systematic error. We conduct a simulation to more fully flesh out the theoretical model. We also conduct a theoretical analysis aimed at determining how significantly these two methods differ. We find that all results are in accordance with the theory but combining experts later …

Techno-Economic Analysis Of Hydrogen Fuel Cell Systems Used As An Electricity Storage Technology In A Wind Farm With Large Amounts Of Intermittent Energy, Yash Sanghai

Masters Theses 1911 - February 2014

With the growing demand for electricity, renewable sources of energy have garnered a lot of support from all quarters. The problem with depending on these renewable sources is that the output from them is independent of the demand. Storage of electricity gives us an opportunity to effectively manage and balance the supply and demand of electricity. Fuel cells are a fast developing and market capturing technology that presents efficient means of storing electricity in the form of hydrogen. The aim of this research is to study the impact of integrating hydrogen fuel cell storage system with a wind farm to …

Background And Available Potential Energy In Numerical Simulations Of A Boussinesq Fluid, Shreyas S. Panse

Masters Theses 1911 - February 2014

In flows with stable density stratification, a portion of the gravitational potential energy is available for conversion to kinetic energy. The remainder is not and is called “background potential energy”. The partition of potential energy is analogous to the classical division of energy due to motion into its kinetic and internal components. Computing background and available potential energies is important for understanding stratified flows. In many numerical simulations, though, the Boussinesq approximations to the Navier-Stokes equations are employed. These approximations are not consistent with conservation of energy. In this thesis we re-derive the governing equations for a buoyancy driven fluid …

Interference Cancellation In Wideband Receivers Using Compressed Sensing, Tejaswi C. Peyyeti

Masters Theses 1911 - February 2014

Previous approach for narrowband interference cancellation based on compressed sensing (CS) in wideband receivers uses orthogonal projections to project away from the interference. This is not effective in the presence of nonlinear LNA (low noise amplifier) and finite bit ADCs (analog-to-digital converters) due to the fact that the nonidealities present will result in irresolvable intermodulation components and corrupt the signal reconstruction. Cancelling out the interferer before reaching the LNA thus becomes very important. A CS measurement matrix with randomly placed zeros in the frequency domain helps in this regard by removing the effect of interference when the signal measurements are …

Preferred Sensor Selection For Damage Estimation In Civil Structures, Matthew Styckiewicz

Masters Theses 1911 - February 2014

Detecting structural damage in civil structures through non-destructive means is a growing field in civil engineering. There are many viable methods, but they can often be time consuming and costly; requiring large amounts of data to be collected. By determining which data are the most optimal at detecting damage and which are not the methods can be better optimized. The objective of this thesis was to adapt an existing method of data optimization, used for damage detection in mechanical engineering applications, for use with civil structures. The existing method creates Parameter Signatures based on characteristics from the system being analyzed, …

Design Of A Tunable Integrated Roofing Filter For Lte Bands, Nihar Athreyas

Masters Theses 1911 - February 2014

The advent of new standards in wireless communication like the Long Term Evolution (LTE) has resulted in a need for newer and better design of receivers for wireless communication systems, the first step of which is to design a tunable integrated filter on the receiver front end.

In this work we propose a new design for a passive tunable integrated Roofing filter for LTE bands. The role of the Roofing filter is to protect the rest of the circuitry from overloading and distortions caused due to large out-of-band signals. This filter protects the rest of the circuitry and hence it …

Low Cost Dynamic Architecture Adaptation Schemes For Drowsy Cache Management, Nitin Prakash

Masters Theses 1911 - February 2014

Energy consumption and speed of execution have long been recognized as conflicting requirements for processor design. In this work, we have developed a low-cost dynamic architecture adaptation scheme to save leakage power in caches. This design uses voltage scaling to implement drowsy caches. The importance of a dynamic scheme for managing drowsy caches, arises from the fact that not only does cache behavior change from one application to the next, but also during different phases of execution within the same application. We discuss various implementations of our scheme that provide a tradeoff between granularity of control and design complexity. …

Factors Which Influence Key Entry Speed On Hard And Soft Keyboards: Experience, Eye Behaviors And Finger Movements, Seckin Celik

Masters Theses 1911 - February 2014

Soft keyboards have become ubiquitous, especially with the introduction of the iPad. This study aims to determine for experienced touch typists whether there are characteristics of soft QWERTY keyboards that can make them easier to use and why those characteristics provide an advantage. Two characteristics would appear to be of central importance. First, hard keyboards provide home row positioning information that is not as easily provided by soft keyboards. Second, hard keyboards also provide auditory and tactile feedback when a key is depressed, something not generally provided with soft keyboards.

In order to test the hypothesis that the absence of …

Evaluating At-Grade Rail Crossing Safety Along The Knowledge Corridor In Massachusetts, Timothy P. Horan

Masters Theses 1911 - February 2014

Highway-rail grade crossings are safer than ever, but collisions between motor vehicles and trains persist. Some collisions could be prevented by actively maintaining such grade crossings, yet many at-grade rail crossings are only evaluated following collisions. Those crossings that experience no collisions may go decades without being inspected. In recent years, the Congress has allocated funds for a national High-Speed Intercity Passenger Rail program, and it is in the public’s interest for state road/highway agencies to inspect all highway-rail crossings in high-speed rail corridors to ensure that the warning systems in place are commensurate with the crossings’ needs. The objectives …

Protecting Network Processors With High Performance Logic Based Monitors, Harikrishnan Kumarapillai Chandrikakutty

Masters Theses 1911 - February 2014

Technological advancements have transformed the way people interact with the world. The Internet now forms a critical infrastructure that links different aspects of our life like personal communication, business transactions, social networking, and advertising. In order to cater to this ever increasing communication overhead there has been a fundamental shift in the network infrastructure. Modern network routers often employ software programmable network processors instead of ASIC-based technology for higher throughput performance and adaptability to changing resource requirements. This programmability makes networking infrastructure vulnerable to new class of network attacks by compromising the software on network processors. This issue has resulted …

Activity Intent Recognition Of The Torso Based On Surface Electromyography And Inertial Measurement Units, Zhe Zhang

Masters Theses 1911 - February 2014

This thesis presents an activity mode intent recognition approach for safe, robust and reliable control of powered backbone exoskeleton. The thesis presents the background and a concept for a powered backbone exoskeleton that would work in parallel with a user. The necessary prerequisites for the thesis are presented, including the collection and processing of surface electromyography signals and inertial sensor data to recognize the user’s activity. The development of activity mode intent recognizer was described based on decision tree classification in order to leverage its computational efficiency. The intent recognizer is a high-level supervisory controller that belongs to a three-level …

A Novel Reconfiguration Scheme In Quantum-Dot Cellular Automata For Energy Efficient Nanocomputing, Madhusudan Chilakam

Masters Theses 1911 - February 2014

Quantum-Dot Cellular Automata (QCA) is currently being investigated as an alternative to CMOS technology. There has been extensive study on a wide range of circuits from simple logical circuits such as adders to complex circuits such as 4-bit processors. At the same time, little if any work has been done in considering the possibility of reconfiguration to reduce power in QCA devices. This work presents one of the first such efforts when considering reconfigurable QCA architectures which are expected to be both robust and power efficient. We present a new reconfiguration scheme which is highly robust and is expected to …

The Effect Of Roadside Elements On Driver Behavior And Run-Off-The-Road Crash Severity, Cole D. Fitzpatrick

Masters Theses 1911 - February 2014

Roadside vegetation provides numerous environmental and psychological benefits to drivers. Previous studies have shown that natural landscapes can effectively lower crash rates and cause less stress and frustration to the driver. However, run-off-the-road crashes resulting in a collision with a tree are twice as likely to result in a fatality, thus reinforcing the need to examine the placement of vegetation within the clear zone. This study explores the relationship between the size of the clear zone and the presence of roadside vegetation on selected driver attributes, including both driver speed and lateral positioning. To evaluate the effect on the driver …

Water Plans And Climate Change Plans In The Northeast And The Southwest, An Pham

Masters Theses 1911 - February 2014

To what degree are water managers in different regions in the United States thinking about and planning for climate change? To answer this question we reviewed water plans and climate change plans in all the cities with populations over 50,000 in the Northeastern and Southwestern regions of the United States. By locating and reviewing water and climate change plans in the described cities in the two regions, we found that of the 101 cities with over 50,000 people in the Northeast, 83 cities had water plans and/or climate change plans that could be found online; only 20 had plans that …

Rbc Lifespan Uncertainty: Models And Anemia Management Robustness, Rui Dai

Masters Theses 1911 - February 2014

This thesis discusses the modeling of uncertainty of red blood cell (RBC) lifespan distribution in patients suffering from Chronic Kidney Disease(CKD) patients, whose anemia is managed through periodic dosing of erythropoietin (EPO).

In healthy individuals, RBCs containing hemoglobin (Hgb) are produced in the bone marrow. When oxygen carried by hemoglobin is transported to human tissues throughout the body, the kidneys sense reduced level of Hgb and secretes EPO that simulates proliferation of red cell precursors and eventually producing red blood cells. However, in CKD patients, their kidneys fail to secrete enough EPO, so that too few of RBCs are produced …

Operational And Safety-Based Analyses Of Varied Toll Lane Configurations, Ian A. Mckinnon

Masters Theses 1911 - February 2014

Toll plaza operation is a critical component of roadway operations throughout the United States, as tolls provide both revenue for expansion and opportunity for demand management. Originally cash or physical currency based, tolling has morphed to meet the twentieth century demand in terms of throughput and efficiency in the form of electronic toll collection. Electronic tolling has introduced a new form of driver decision making at toll plazas due to the additional payment choice. Despite the user convenience these facilities provide to consumers, this form of collection has not come without safety and operational concerns. Confusion at the toll plaza, …

A New Class Of Improved Bandwidth Planar Ultrawideband Modular Antenna (Puma) Arrays Scalable To Mm-Waves, John Logan

Masters Theses 1911 - February 2014

A new class of Planar Ultrawideband Modular Antenna (PUMA) arrays, termed PUMAv3, is introduced to offer improved performance and further meet demand needs for multifunctional systems. PUMAv3 extends the frequency scalability of PUMA arrays to mm-waves (approximately 50 GHz) and improves bandwidth by 50\% without the use of a matching network or external baluns. The major enabling technical innovation is the advent of a new common-mode mitigation mechanism that relies upon capacitively-loaded shorting vias to push broadside catastrophic resonances below the operating band without inhibiting low-end bandwidth performance. Ridged waveguide models are employed to explain the operational principles and accurately …

A Dynamic Reconfiguration Framework To Maximize Performance/Power In Asymmetric Multicore Processors, Arunachalam Annamalai

Masters Theses 1911 - February 2014

Recent trends in technology scaling have shifted the processing paradigm to multicores. Depending on the characteristics of the cores, the multicores can be either symmetric or asymmetric. Prior research has shown that Asymmetric Multicore Processors (AMPs) outperform their symmetric (SMP) counterparts within a given resource and power budget. But, due to the heterogeneity in core-types and time-varying workload behavior, thread-to-core assignment is always a challenge in AMPs. As the computational requirements vary significantly across different applications and with time, there is a need to dynamically allocate appropriate computational resources on demand to suit the applications’ current needs, in order to …

Multi Rotor Wind Turbine Design And Cost Scaling, Preeti Verma

Masters Theses 1911 - February 2014

The current generation wind turbines are upscaled into multi megawatt range in terms of output power. However, the energy benefit from the turbine is offset by the increased mass and cost. Twenty MW wind turbines are now feasible with rotor diameters up to 200 m, according to a new report from the EU-funded UpWind project in 2011. The question is, how much bigger can wind turbines get realistically? One concept worth considering, and the one that is the subject of this thesis, is to have more than one rotor on a single support structure. Such turbines could have a greater …

Optimization Of Mixing In A Simulated Biomass Bed Reactor With A Center Feeding Tube, Michael T. Blatnik

Masters Theses 1911 - February 2014

Producing gasoline-type fuels from lignocellulosic biomass has two advantages over producing alcohol-type fuels from plant sugars: gasoline has superior fuel characteristics and plant lignin/cellulose does not compete with human food supplies. A promising technology for converting lignocellulose to fuel is catalytic fast pyrolysis (CFP). The process involves injecting finely ground biomass into a fluidized bed reactor (FBR) at high temperatures, which reduce the biomass to gases that react inside the catalyst particles. This entails complex hydrodynamics to efficiently mix a stream of biomass into a catalyst bed that is fluidized by a separate stream of inert gas. Understanding the hydrodynamics …