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 …

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 …

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 …

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 …

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. …

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 …

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 …

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 …

Parameter Variation Sensing And Estimation In Nanoscale Fabrics, Jianfeng Zhang

Masters Theses 1911 - February 2014

Parameter variations introduced by manufacturing imprecision are becoming more influential on circuit performance. This is especially the case in emerging nanoscale fabrics due to unconventional manufacturing steps (e.g., nano-imprint) and aggressive scaling. These parameter variations can lead to performance deterioration and consequently yield loss.

Parameter variations are typically addressed pre-fabrication with circuit design targeting worst-case timing scenarios. However, this approach is pessimistic and much of performance benefits can be lost. By contrast, if parameter variations can be estimated post-manufacturing, adaptive techniques or reconfiguration could be used to provide more optimal level of tolerance. To estimate parameter variations during run-time, on-chip …

Online Nbti Wear-Out Estimation, Mehernosh H. Dabhoiwala

Masters Theses 1911 - February 2014

CMOS feature size scaling has been a source of dramatic performance gains, but it has come at a cost of on-chip wear-out. Negative Bias Temperature Instability (NBTI) is one of the main on-chip wear-out problems which questions the reliability of a chip. To check the accuracy of Reaction-Diffusion (RD) model, this work first proposes to compare the NBTI wear-out data from the RD wear-out model and the reliability simulator - Ultrasim RelXpert, by monitoring the activity of the register file on a Leon3 processor. The simulator wear-out data obtained is considered to be the baseline data and is used to …

A Non-Linear Eigensolver-Based Alternative To Traditional Self-Consistent Electronic Structure Calculation Methods, Brendan E. Gavin

Masters Theses 1911 - February 2014

This thesis presents a means of enhancing the iterative calculation techniques used in electronic structure calculations, particularly Kohn-Sham DFT. Based on the subspace iteration method of the FEAST eigenvalue solving algorithm, this nonlinear FEAST algorithm (NLFEAST) improves the convergence rate of traditional iterative methods and dramatically improves their robustness. A description of the algorithm is given, along with the results of numerical experiments that demonstrate its effectiveness and offer insight into the factors that determine how well it performs.

Sige Millimeter-Wave (W-Band) Down-Converter For Phased Focal Plane Array, Maruthi Nagavalli Yogeesh

Masters Theses 1911 - February 2014

A millimeter-wave (W-Band) down-converter for Phased Focal Plane Arrays (PFPAs) has been designed and fabricated using the IBM Silicon-Germanium (SiGe) BiCMOS 8HP process technology. The radio frequency (RF) input range of the down-converter chip is from 70 95GHz. The intermediate frequency (IF) range is from 5 30GHz. The local oscillator (LO) frequency is fixed at 65GHz. The down-converter chip has been designed to achieve a conversion gain greater than 20dB, a noise figure (NF) below 10dB and input return loss greater than 10dB. The chip also has novel LO circuitry facilitating LO feed-through among down-converters chips in parallel. This wide …

Design Of An Open-Source Sata Core For Virtex-4 Fpgas, Cory Gorman

Masters Theses 1911 - February 2014

Many hard drives manufactured today use the Serial ATA (SATA) protocol to communicate with the host machine, typically a PC. SATA is a much faster and much more robust protocol than its predecessor, ATA (also referred to as Parallel ATA or IDE). Many hardware designs, including those using Field-Programmable Gate Arrays (FPGAs), have a need for a long-term storage solution, and a hard drive would be ideal. One such design is the high-speed Data Acquisition System (DAS) created for the NASA Surface Water and Ocean Topography mission. This system utilizes a Xilinx Virtex-4 FPGA. Although the DAS includes a SATA …

Analysis Of Sensor Data In Cyber-Physical System, Xianglong Kong

Masters Theses 1911 - February 2014

Cyber-Physical System (CPS) becomes more and more importance from industrial application (e.g., aircraft control, automation management) to societal challenges (e.g. health caring, environment monitoring). It has traditionally been designed to one specific application domain and to be managed by a single entity, implemented communication between physical world and computational world. However, it still just work within its domain, and not be interoperability. How to make it into scalable? How to make it reusing? These questions become more and more necessary. In this paper, we are trying to developing a common CPS infrastructure, let it be an innovative CPS crossing multiple …

Enhancing Secrecy Via Exploring Randomness In The Wireless Physical Layer, Rehan Talat

Masters Theses 1911 - February 2014

In order to establish a secure connections in the wireless environment, cryptographic methods may require an exchange of a key or secret. Fortunately, the environment provides randomness due to multi-path fading that can be exploited by physical-layer security algorithms to help establish this shared secret. However, in some cases, multi-path fading might be absent or negligible; therefore, we look for artificial ways to increase randomness. In this thesis, we explore antenna radiation variation by altering the phase between two antennas as a means of creating artificial fading. We construct a model of the antenna gain variation by analyzing the radiation …

An Interconnection Network Topology Generation Scheme For Multicore Systems, Bharath Phanibhushana

Masters Theses 1911 - February 2014

Multi-Processor System on Chip (MPSoC) consisting of multiple processing cores connected via a Network on Chip (NoC) has gained prominence over the last decade. Most common way of mapping applications to MPSoCs is by dividing the application into small tasks and representing them in the form of a task graph where the edges connecting the tasks represent the inter task communication. Task scheduling involves mapping task to processor cores so as to meet a specified deadline for the application/task graph. With increase in system complexity and application parallelism, task communication times are tending towards task execution times. Hence the NoC …

N3asics: Designing Nanofabrics With Fine-Grained Cmos Integration, Pavan Panchapakeshan

Masters Theses 1911 - February 2014

Nanoscale-computing fabrics based on novel materials such as semiconductor nanowires, carbon nanotubes, graphene, etc. have been proposed in recent years. These fabrics employ unconventional manufacturing techniques like Nano-imprint lithography or Super-lattice Nanowire Pattern Transfer to produce ultra-dense nano-structures. However, one key challenge that has received limited attention is the interfacing of unconventional/self-assembly based approaches with conventional CMOS manufacturing to build integrated systems.

We propose a novel nanofabric approach that mixes unconventional nanomanufacturing with CMOS manufacturing flow and design rules to build a reliable nanowire-CMOS 3-D integrated fabric called N³ASICs with no new manufacturing constraints. In N³ASICs …

Impact Of Manufacturing Flow On Yield Losses In Nanoscale Fabrics, Priyamvada Vijayakumar

Masters Theses 1911 - February 2014

Reliable and scalable manufacturing of nanofabrics entails significant challenges. Scalable nano-manufacturing approaches that employ the use of lithographic masks in conjunction with nanofabrication based on self-assembly have been proposed. A bottom-up fabrication of nanoelectronic circuits is expected to be subject to various defects and identifying the types of defects that may occur during each step of a manufacturing pathway is essential in any attempt to achieve reliable manufacturing. This thesis aims at analyzing the sources of defects in a nano-manufacturing flow and estimating the resulting yield loss. It integrates physical fabric considerations, manufacturing sequences and the resulting defect scenarios. This …

Secure And Energy Efficient Physical Unclonable Functions, Sudheendra Srivathsa

Masters Theses 1911 - February 2014

Physical Unclonable Functions are a unique class of circuits that leverage the inherentvariations in manufacturing process to create unique,unclonableIDs and secret keys.The distinguishing feature of PUFs is that even an untrusted foundry cannot create a copy of the circuit as it is impossible to control the manufacturing process variations.PUFs can operate reliably in presence of voltage and temperature variations. In thisthesis, weexplorethe security offered by PUFs and tradeoffs between different metrics such as uniqueness, reliability and energy consumption.Benefits of sub-threshold PUF operation and the use of delay based Arbiter PUFs and ring oscillator PUFs in low power applications is evaluated. …

Implementation Of Dual-Polarization On An Airborne Scatterometer And Preliminary Data Quality, Jason Dvorsky

Masters Theses 1911 - February 2014

The Imaging Wind and RAin Profiler (IWRAP) is an airborne scatterometer system built and operated by University of Massachusetts Amherst's Microwave Remote Sensing Laboratory (MIRSL). The radar is seasonally deployed aboard one of the two National Oceanic and Atmospheric Administration (NOAA) WP-3D Orion ``Hurricane Hunter'' aircraft based out of MacDill AFB in Tampa, Florida. IWRAP is a dual-frequency, Ku- and C-band, scatterometer that uses two conically scanning antennas to estimate the ocean surface wind vectors as well as intervening rain profiles. Data that is gathered with IWRAP is used to improve current Geophysical Model Functions (GMF) or to help derive …

A Study Of The Impact Of Computational Delays In Missile Interception Systems, Ye Xu

Masters Theses 1911 - February 2014

Most publications discussing missile interception systems assume a zero computer response time. This thesis studies the impact of computer response time on single-missile single-target and multiple- missile multiple-target systems. Simulation results for the final miss distance as the computer response time increases are presented. A simple online cooperative adjustment model for multiple-missile multiple-target system is created for the purpose of studying the computer delay effect.

Critical Area Driven Dummy Fill Insertion To Improve Manufacturing Yield, Nishant Dhumane

Masters Theses 1911 - February 2014

Non-planar surface may cause incorrect transfer of patterns during lithography. In today’s IC manufacturing, chemical mechanical polishing (CMP) is used for topographical planarization. Since polish rates for metals and oxides are different, dummy metal fills in layout is used to minimize post-CMP thickness variability. Traditional metal fill solutions focus on satisfying density target determined by layout density analysis techniques. These solutions may potentially reduce yield by increasing probability of failure (POF) due to particulate defects and also impact design performance. Layout design solutions that minimize POF and also improve surface planarity via dummy fill insertions have competing requirements for line …