Engineering Commons^™

Simulating A Universal Geocast Scheme For Vehicular Ad Hoc Networks, Benjamin L. Bovee

Masters Theses 1911 - February 2014

Recently a number of communications schemes have been proposed for Vehicular Ad hoc Networks (VANETs). One of these, the Universal Geocast Scheme (UGS) proposed by Hossein Pishro-Nik and Mohammad Nekoui, provides for a diverse variety of VANET-specific characteristics such as time-varying topology, protocol variation based on road congestion, and support for non line-of-sight communication. In this research, the UGS protocol is extended to consider inter-vehicle multi-hop connections in intersections with surrounding obstructions along with single-hop communications in an open road scenario. Since UGS is a probabilistic, repetition-based scheme, it supports the capacity-delay tradeoffs crucial for periodic safety message exchange. The …

Design And Testing Of A Prototype High Speed Data Acquisition System For Nasa, Vishwas Tumkur Vijayendra

Masters Theses 1911 - February 2014

Modern radar and signal processing applications require data acquisition systems capable of high-speed analog data reception and processing. These systems need to support sophisticated signal processing algorithms and reliable high-speed interfaces. The objective of this project is to develop a prototype of a state of the art data acquisition system to aid NASA’s Surface Water and Ocean Topography (SWOT) mission. The SWOT mission aims at monitoring water levels of various water bodies to predict and avoid any catastrophic events. The principal instrument is a Ka-band Radar Interferometer (KaRIN) that is used for the measurement of water levels. The collected data …

Wireless Physical-Layer Security Performance Of Uwb Systems, Miyong Ko

Masters Theses 1911 - February 2014

Traditionally, spread-spectrum systems have been employed to provide low probability-of-intercept (LPI) and low probability-of-detection (LPD) performances at the physical layer, but the messages transmitted over such a system are still encrypted with a powerful cipher to protect their secrecy. Our challenge is to find a solution to provide an additional level of security at the physical layer so that simple systems such as RFID tags with limited resources can be secure without using standard encryption. It has recently been suggested that the cryptographic security of the system can be enhanced by exploiting physical properties of UWB signals. With an eavesdropper …

On The Retrieval Of The Beam Transverse Wind Velocity Using Angles Of Arrival From Spatially Separated Light Sources, Shiril Tichkule

Masters Theses 1911 - February 2014

For optical propagation through the turbulent atmosphere, the angle of arrival (AOA) cross-correlation function obtained from two spatially separated light sources carries information regarding the transverse wind velocity averaged along the propagation path. Two methods for the retrieval of the beam transverse horizontal wind velocity, v_t, based on the estimation of the time delay to the peak and the slope at zero lag of the AOA cross-correlation function, are presented. Data collected over a two week long experimental campaign conducted at the Boulder Atmospheric Observatory (BAO) site near Erie, CO was analyzed. The RMS difference between 10 s estimates of …

Physical Information Theoretic Bounds On Energy Costs For Error Correction, Natesh Ganesh

Masters Theses 1911 - February 2014

With diminishing returns in performance with scaling of traditional transistor devices, there is a growing need to understand and improve potential replacements technologies. Sufficient reliability has not been established in these devices and additional redundancy through use of fault tolerance and error correction codes are necessary. There is a price to pay in terms of energy and area, with this additional redundancy. It is of utmost importance to determine this energy cost and relate it to the increased reliability offered by the use of error correction codes. In this thesis, we have determined the lower bound for energy dissipation associated …

Inversion Of Marine Radar Imagery To Surface Realizations And Dual-Polarization Analysis, Brian Paulsen

Masters Theses 1911 - February 2014

The ocean influences global weather patterns, stores and transports heat, and supports entire ecosystems. An area of interest is the relationship between the observed backscattered power received by a surface-based marine radar and the ocean surface topography. Current methods for obtaining surface elevation maps involve either in situ devices, which only provide point measurements, or an interferometric radar, which can be costly. During the late 1990's and early 2000's a radar was built at UMass, called the Focused Phased Array Imaging Radar II (FOPAIR II), and deployed at a several locations. A method is discussed to determine a transfer function …

Functional Verification Of Arithmetic Circuits Using Linear Algebra Methods, Mohamed Basith Abdul Ameer Abdul Kader

Masters Theses 1911 - February 2014

This thesis describes an efficient method for speeding up functional verification of arithmetic circuits namely linear network such as wallace trees, counters using linear algebra techniques. The circuit is represented as a network of half adders, full adders and inverters, and modeled as a system of linear equations. The proof of functional correctness of the design is obtained by computing its algebraic signature using standard linear programming (LP) solver and comparing it with the reference signature provided by the designer. Initial experimental results and comparison with Satisfiability Modulo Theorem (SMT) solvers show that the method is efficient, scalable and applicable …

Addressing/Exploiting Transceiver Imperfections In Wireless Communication Systems, Lihao Wang

Masters Theses 1911 - February 2014

This thesis consists of two research projects on wireless communication systems. In the first project, we propose a fast inphase and quadrature (I/Q) imbalance compensation technique for the analog quadrature modulators in direct conversion transmitters. The method needs no training sequence, no extra background data gathering process and no prior perfect knowledge of the envelope detector characteristics. In contrast to previous approaches, it uses points from both the linear and predictable nonlinear regions of the envelope detector to hasten convergence. We provide a least mean square (LMS) version and demonstrate that the quadrature modulator compensator converges.

In the second project, …

Gpu Based Lithography Simulation And Opc, Lokesh Subramany

Masters Theses 1911 - February 2014

Optical Proximity Correction (OPC) is a part of a family of techniques called Resolution Enhancement Techniques (RET). These techniques are employed to increase the resolution of a lithography system and improve the quality of the printed pattern. The fidelity of the pattern is degraded due to the disparity between the wavelength of light used in optical lithography, and the required size of printed features. In order to improve the aerial image, the mask is modified. This process is called OPC, OPC is an iterative process where a mask shape is modified to decrease the disparity between the required and printed …

Automated Detection And Counting Of Pedestrians On An Urban Roadside, Gayatri D. Prabhu

Masters Theses 1911 - February 2014

This thesis implements an automated system that counts pedestrians with 85% accuracy. Two approaches have been considered and evaluated in terms of count accuracy, cost and ease of deployment. The first approach employs the Autoscope Solo Terra, a traffic camera which is widely used to monitor vehicular traffic. The Solo Terra supports an image processing-based detector that counts the number of objects crossing user-defined areas in the captured image. The count is updated based on the amount of movement across the selected regions. Therefore, a second approach has been considered that uses a histogram of oriented gradients (HoG), an advanced …

Design Of An Fpga-Based Array Formatter For Casa Phase-Tilt Radar System, Akilesh Krishnamurthy

Masters Theses 1911 - February 2014

Weather monitoring and forecasting systems have witnessed rapid advancement in recent years. However, one of the main challenges faced by these systems is poor coverage in lower atmospheric regions due to earth's curvature. The Engineering Research Center for the Collaborative Adaptive Sensing of the Atmosphere (CASA) has developed a dense network of small low-power radars to improve the coverage of weather sensing systems. Traditional, mechanically-scanned antennas used in these radars are now being replaced with high-performance electronically-scanned phased-arrays. Phased-Array radars, however, require large number of active microwave components to scan electronically in both the azimuth and elevation planes, thus significantly …

Integrated Cmos Iq Upconverter/Downconverter For An X-Band Phased-Array Radar Application, Ryan C. Johnson

Masters Theses 1911 - February 2014

This thesis describes the design and measurement of an X-band IQ up/down converter that has been fabricated on a 180nm RF CMOS process. This converter includes components for mixing, frequency doubling, quadrature generation, amplification, and limiting. The specific circuit topologies used include passive double-balanced mixers, RC polyphase filters, and injection locked LC oscillators.

The converter is part of a transceiver chain that will make up the dedicated circuitry for each active antenna element of a phased-array radar. An active antenna element combines a radiator with its own transceiver subsystem. A phased-array radar, NetRad, is under development at the University of …

Load Hindcasting: A Retrospective Regional Load Prediction Method Using Reanalysis Weather Data, Jonathan D. Black

Masters Theses 1911 - February 2014

The capacity value (CV) of a power generation unit indicates the extent to which it contributes to the generation system adequacy of a region’s bulk power system. Given the capricious nature of the wind resource, determining wind generation’s CV is nontrivial, but can be understood simply as how well its power output temporally correlates with a region’s electricity load during times of system need. Both wind generation and load are governed by weather phenomena that exhibit variability across all timescales, including low frequency weather cycles that span decades. Thus, a data-driven determination of wind’s CV should involve the use of …

Robust Signaling Techniques For Through Silicon Via Bundles, Krishna Chaitanya Chillara

Masters Theses 1911 - February 2014

3D circuit integration is becoming increasingly important as one of the remaining techniques for staying on Moore’s law trajectory. 3D Integrated Circuits (ICs) can be realized using the Through Silicon Via (TSV) approach. In order to extract the full benefits of 3D and for better yield, it has been suggested that the TSVs should be arranged as bundles rather than parallel TSVs. TSVs are required to route the signals through different dies in a multi-tier 3D IC. TSVs are excellent but scarce electrical conductors. Hence, it is important to utilize these resources very efficiently.

In high performance 3D ICs, signaling …

Electromagnetic Side-Channel Analysis For Hardware And Software Watermarking, Ashwin Lakshminarasimhan

Masters Theses 1911 - February 2014

With more and more ICs being used in sectors requiring confidentiality and integrity like payment systems, military, finance and health, there is a lot of concern in the security and privacy of ICs. The widespread adoption of Intellectual Property (IP) based designs for modern systems like system on chips has reduced the time to market and saved a lot of money for many companies. But this has also opened the gates for problems like product piracy, IP theft and fraud. It is estimated that billions of dollars are lost annually to illegal manufacturing of Integrated Circuits. A possible solution to …

Development, Deployment, And Characterization Of A Ku-Band Interferometer, Anthony Swochak

Masters Theses 1911 - February 2014

Space-borne radar interferometry provides a global vantage point to understand climate change, global weather phenomenon, and other Earth dynamics. For climate change observations, space-borne interferometers can be utilized to relate ocean topography to temperature, thus providing a global map of ocean temperatures. Since the oceans are in constant motion, a single-pass interferometer is needed to successfully make these measurements of ocean height. The feasibility of a single-pass measurement is dependent on the physical size of the instrument, hence it is cheaper and more practical to launch a small, light weight instrument into space. Since instrument size scales inversely with operating …

Terahertz Radiation From Single Walled Carbon Nanotubes, Martin M. Muthee

Masters Theses 1911 - February 2014

The Terahertz region of the electromagnetic spectrum is the region between microwaves and infra-red, dubbed the terahertz 'gap' due to its relative underdevelopment in terms of technology. This region is marked by expensive and inconvenient sources that are bulky or that require cryogenic cooling for normal operation, therefore creating a need for cheap and easy to use terahertz sources.

Carbon nanotubes have received considerable attention since their discovery due to their unique physical and electronic properties. Many applications have been proposed using especially Single-Walled Carbon Nanotubes (SWCNTs), and a number of commercial technologies exist. In this work, we have proposed …

On Process Variation Tolerant Low Cost Thermal Sensor Design, Spandana Remarsu

Masters Theses 1911 - February 2014

Thermal management has emerged as an important design issue in a range of designs from portable devices to server systems. Internal thermal sensors are an integral part of such a management system. Process variations in CMOS circuits cause accuracy problems for thermal sensors which can be fixed by calibration tables. Stand-alone thermal sensors are calibrated to fix such problems. However, calibration requires going through temperature steps in a tester, increasing test application time and cost. Consequently, calibrating thermal sensors in typical digital designs including mainstream desktop and notebook processors increases the cost of the processor. This creates a need for …

Enhanced Search And Efficient Storage Using Data Compression In Nand Flash Memories, Shruti S. Vyas

Masters Theses 1911 - February 2014

NAND flash memories are popular due to their density and lower cost. However, due to serial access, NAND flash memories have low read and write speeds. As the flash sizes increase to 64GB and beyond, searches through flash memories become painfully slow. In this work we present a hardware design enhancement technique to speed-up search through flash memories. The basic idea is to generate a small signature for every memory block and store them in a signature block(s). When a search is initiated, signature block is searched which produces reference of possible blocks where data might be contained, reducing the …

Testable Clock Distributions For 3d Integrated Circuits, Michael T. Buttrick

Masters Theses 1911 - February 2014

The 3D integration of dies promises to address the problem of increased die size caused by the slowing of scaling. By partitioning a design among two or more dies and stacking them vertically, the average interconnect length is greatly decreased and thus power is reduced. Also, since smaller dies will have a higher yield, 3D integration will reduce manufacturing costs. However, this increase in yield can only be seen if manufactured dies can be tested before they are stacked. If not, the overall yield for the die stack will be worse than that of the single, larger die.

One of …

An Electronically Reconfigurable Three Band Low-Noise Amplifier In 0.5 Μm Gaas Phemt Technology, Jeffrey A. Shatzman

Masters Theses 1911 - February 2014

State-of-the-art RF front-end circuits are typically designed to operate at a single frequency. With an increasing number of available wireless standards, personal mobile communication devices require an increasing number of individually designed RF circuits. To save space and cost, one alternative possibility is to reuse much of the circuitry by utilizing electronically reconfigurable topologies. The ubiquitous low-noise amplifier is one of the many circuits that can be redesigned with the reconfigurable aspect in mind. In this thesis, previous work in reconfigurable LNAs is reviewed as well as a brief comparison of CMOS and GaAs processes used for RF amplifiers. Three …

Transmission-Line Metamaterial Design Of An Embedded Line Source In A Ground Recess, Caglar D. Emiroglu

Masters Theses 1911 - February 2014

A transmission-line metamaterial design of a material-embedded electric line source radiating inside a ground recess is investigated. The media embedding the recessed line source are designed such that the embedded current creates the same radiation pattern as a line source over a flat conducting ground plane. Transmission-line metamaterial unit cell designs for the embedding media obtained from the transformation electromagnetics design technique are shown. The metamaterial design of the overall embedded source configuration is numerically tested using circuit simulations. It is shown that the embedded-source design creates the same radiation characteristics as the line source above a flat ground plane …

Resonant Antennas Based On Coupled Transmission-Line Metamaterials, Christopher S. Merola

Masters Theses 1911 - February 2014

A novel microstrip patch antenna topology is presented for achieving a dual-band response with arbitrarily closely spaced resonances. This topology is based on a coupled transmission line structure in order to take advantage of the separation in propagation constants for parallel (even-mode) and anti-parallel (odd-mode) current modes. Applying a metamaterials inspired design approach, periodic reactive load­ings are used to design the underlying transmission line to have specific propagation constants necessary to realize a desired separation between two resonant frequencies. Using a single probe feed for a finite coupled line segment, both even-and odd-mode resonances can be excited to radiate efficiently …

Electromagnetic Modeling Of Photolithography Aerial Image Formation Using The Octree Finite Element Method, Seth A. Jackson

Masters Theses 1911 - February 2014

Modern semiconductor manufacturing requires photolithographic printing of subillumination wavelength features in photoresist via electromagnetic energy scattered by complicated photomask designs. This results in aerial images which are subject to constructive and destructive wave interference, as well as electromagnetic resonances in the photomask features. This thesis proposes a 3-D full-wave frequency domain nonconformal Octree mesh based Finite Element Method (OFEM) electromagnetic scattering solver in combination with Fourier Optics to accurately simulate the entire projection photolithography system, from illumination source to final image intensity in the photoresist layer. A rapid 1-irregular octree based geometry model mesher is developed and shown to perform …