Engineering Commons^™

Post Silicon Clock Tuning System To Mitigate The Impact Of Process Variation On Performance, Kelageri Nagaraj

Masters Theses 1911 - February 2014

Optical shrink for process migration, manufacturing process variation and dynamic voltage control leads to clock skew as well as path delay variation in a manufactured chip. Since such variations are difficult to predict in pre-silicon phase, tunable clock buffers have been used in several microprocessor designs. The buffer delays are tuned to improve maximum operating clock frequency of a design. This however shifts the burden of finding tuning settings for individual clock buffers to the test process. In this project, we describe a process of using tester measurements to determine the settings of the tunable buffers for recovery of performance …

Approaches To Multiprocessor Error Recovery Using An On-Chip Interconnect Subsystem, Ramakrishna P. Vadlamani

Masters Theses 1911 - February 2014

For future multicores, a dedicated interconnect subsystem for on-chip monitors was found to be highly beneficial in terms of scalability, performance and area. In this thesis, such a monitor network (MNoC) is used for multicores to support selective error identification and recovery and maintain target chip reliability in the context of dynamic voltage and frequency scaling (DVFS). A selective shared memory multiprocessor recovery is performed using MNoC in which, when an error is detected, only the group of processors sharing an application with the affected processors are recovered. Although the use of DVFS in contemporary multicores provides significant protection from …

Evaluation Of An Eye Tracking Device To Increase Error Recovery By Nursing Students Using Human Patient Simulation, Yan Shen

Masters Theses 1911 - February 2014

This study evaluates the application of an eye tracking device in nursing education. An experiment is designed to test the effectiveness of the eye tracking device used as a tool for providing instructional feedback in error identification and recovery by nursing students undertaking tasks in a simulated clinical setting. This experiment is performed on three groups of nursing students. In the first phase, all groups are tested in a simulated clinical scenario and their eye movements are recorded using an eye tracking device. In the second phase, the evaluation only group (control group) gets instructors’ feedback regarding their performance without …

Calibration Of The Umass Advanced Multi-Frequency Radar, Matthew Mclinden

Masters Theses 1911 - February 2014

The Advanced Multi-Frequency Radar is a three-frequency system designed and built by the University of Massachusetts Microwave Remote Sensing Lab (MIRSL). The radar has three frequencies, Ku-band (13.4 GHz), Ka-band (35.6 GHz), and W-band (94.92GHz). The additional information gained from additional frequencies allows the system to be sensitive to a wide range of atmospheric and precipitation particle sizes, while increasing the ability to derive particle microphysics from radar retrievals.

This thesis details the calibration of data from the Canadian CloudSat/CALIPSO Validation Project (C3VP) held during January 2007 in Ontario, Canada. The calibration used internal calibration path data and was confirmed …

Evaluating A New Mac For Current And Next Generation Rfid, Serge Zhilyaev

Masters Theses 1911 - February 2014

We evaluate SQUASH, a new MAC for RFID, in hardware and software. A smaller hardware design for SQUASH is proposed which also reduces latency. Area and latency in hardware are reduced further with a new variant we call permuted SQUASH. We explore SQUASH on embedded microprocessors and propose a method to choose the optimal partial product ordering to reduce latency.

Sorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song

Masters Theses 1911 - February 2014

Manufactured oxide nanoparticles (NPs) have large production and widespread applications, which will inevitably enter the environment. NPs can interact with proteins in living beings due to the fact that NPs can transport into blood or across cell membranes into cells. Conformational change of protein molecules after sorption on oxide NPs has been reported. Therefore, it is important to understand the adsorption mechanism of protein onto oxide NPs surfaces. Although few works have reported protein adsorption behaviors, a general systematic comparison of the effects of particle size and surface groups on protein adsorption by widely studied NPs still needs to be …

Route Choice Behavior In Risky Networks With Real-Time Information, Michael D. Razo

Masters Theses 1911 - February 2014

This research investigates route choice behavior in networks with risky travel times and real-time information. A stated preference survey is conducted in which subjects use a PC-based interactive maps to choose routes link-by-link in various scenarios. The scenarios include two types of maps: the first presenting a choice between one stochastic route and one deterministic route, and the second with real-time information and an available detour. The first type measures the basic risk attitude of the subject. The second type allows for strategic planning, and measures the effect of this opportunity on subjects' choice behavior.

Results from each subject are …

A Quantitative Analysis Of The Impacts From Selected Variables Upon Safety Belt Usage In Massachusetts, Samuel W. Gregorio

Masters Theses 1911 - February 2014

Safety belts are the most effective safety device in vehicles in terms of preventing injuries (1). Every year, safety belt usage data across the nation is collected by the individual states, the District of Columbia, and U.S. territories in a probability-based observational survey. Using this survey, Massachusetts, a secondary seat belt law state, ranked last in safety belt usage in 2008. This percentage was approximately a 2 percent decrease from 2007. This value was not an aberration as within the recent past, Massachusetts, a secondary safety belt law state, has consistently ranked at or near the bottom of the 50 …

Scalable, Memory-Intensive Scientific Computing On Field Programmable Gate Arrays, Salma Mirza

Masters Theses 1911 - February 2014

Cache-based, general purpose CPUs perform at a small fraction of their maximum floating point performance when executing memory-intensive simulations, such as those required for many scientific computing problems. This is due to the memory bottleneck that is encountered with large arrays that must be stored in dynamic RAM. A system of FPGAs, with a large enough memory bandwidth, and clocked at only hundreds of MHz can outperform a CPU clocked at GHz in terms of floating point performance. An FPGA core designed for a target performance that does not unnecessarily exceed the memory imposed bottleneck can then be distributed, along …

Fast Parameter-Space Sweep Of Wideband Electromagnetic Systems Using Bt-Pod, Wei Wang

Masters Theses 1911 - February 2014

Modeling and design of high frequency electronic systems such as antennas and microwave devices require the rigorous numerical solution of Maxwell’s equa- tions. The frequency-domain (time-harmonic) tangential vector finite element method (TVFEM) for Maxwell equations results in a second-order dynamical electromagnetic model that must be repeatedly solved for multiple frequencies, excitation or material parameters each design loop. This leads to extremely long design turnaround that often is not optimal. This work will propose an accurate, error controllable and ef- ficient multi-parametric model order reduction scheme that significantly accelerate these parameters sweep. At the core of this work is the proper …

Historic Bridge Evaluation Using Finite Element Techniques, Helena M. Charron

Masters Theses 1911 - February 2014

The present study examined the application of modern, computer-based analysis methods to two existing historic bridges in Massachusetts. The first bridge featured in this study is the Woronoco Bridge, a reinforced concrete open spandrel arch bridge that was constructed in 1923. It was hoped that a computer-based, parametric study of this bridge would prove it to be deck-stiffened, similar to select bridges of Swiss engineer Robert Maillart. However, the results do not support that there was any intent to reduce bending in the arch as a result of increasing the stiffness of the bridge deck. Instead, the Woronoco Bridge appears …

Optical Lithography Simulation Using Wavelet Transform, Rance Rodrigues

Masters Theses 1911 - February 2014

Optical lithography is an indispensible step in the process flow of Design for Manufacturability (DFM). Optical lithography simulation is a compute intensive task and simulation performance, or lack thereof can be a determining factor in time to market. Thus, the efficiency of lithography simulation is of paramount importance. Coherent decomposition is a popular simulation technique for aerial imaging simulation. In this thesis, we propose an approximate simulation technique based on the 2D wavelet transform and use a number of optimization methods to further improve polygon edge detection. Results show that the proposed method suffers from an average error of less …

Simulations Of Flow Over Wind Turbines, Dnyanesh A. Digraskar

Masters Theses 1911 - February 2014

One of the most abundant sources of renewable energy is wind. Today, a considerable amount of resources are being utilized for research on harnessing the wind energy efficiently. Out of all the factors responsible for efficient energy production, the aerodynamics of flow around the wind turbine blades play an important role. This work aims to undertake aerodynamic analysis of a Horizontal Axis Wind Turbine. A steady state, incompressible flow solver for multiple reference frames, MRFSimple- Foam is modified and used for performing simulations of flow over National Renewable Energy Laboratory Phase VI wind turbine rotor. The code is first tested …

Web-Dinar: Web Based Diagnosis Of Network And Application Resources In Disaster Response Systems, Kartik Deshpande

Masters Theses 1911 - February 2014

Disaster management and emergency response mechanisms are coming of age post 9/11. Paper based triaging and evacuation is slowly being replaced with much advanced mechanisms using remote clients (Laptops, Thin clients, PDAs), RFiDs etc. This reflects a modern trend to deploy Information Technology (IT) in disaster management. IT elements provide a great a deal of flexibility and seamlessness in the communication of information. The information flowing is so critical that, loss of data is not at all acceptable. Loss of data would mean loss of critical medical information portraying the disaster scenario. This would amount to a wrong picture being …

Efficient Modeling Techniques For Time-Dependent Quantum System With Applications To Carbon Nanotubes, Zuojing Chen

Masters Theses 1911 - February 2014

The famous Moore's law states: Since the invention of the integrated circuit, the number of transistors that can be placed on an integrated circuit has increased exponentially, doubling approximately every two years. As a result of the downscaling of the size of the transistor, quantum effects have become increasingly important while affecting significantly the device performances. Nowadays, at the nanometer scale, inter-atomic interactions and quantum mechanical properties need to be studied extensively. Device and material simulations are important to achieve these goals because they are flexible and less expensive than experiments. They are also important for designing and characterizing new …

Electronic Falls Reporting System Implementation: Evaluating Data Collection Methods And Studying User Acceptance, Yi You Mei

Masters Theses 1911 - February 2014

In this research, we detail the development of a novel, easy-to-use system to facilitate electronic patient falls reporting within a long-term residential care facility (LTRCF) using off-the-shelf technology that can be inexpensively implemented in a wide variety of settings. We report the results of four complimentary system evaluation measures that take into consideration varied organizational stakeholders’ perspectives: 1) System-level benefits and costs, 2) System usability, via scenario-based use cases, 3) A holistic assessment of users’ physical, cognitive, and marcoergonomic (work system) challenges in using the system, and 4) User technology acceptance. We report the viability of collecting and analyzing data …

Investigation Of The Behavior Of Open Cell Aluminum Foam, Patrick J. Veale

Masters Theses 1911 - February 2014

The study investigates the behavior open cell aluminum foam in scenarios applicable to potential use in structural applications. Behavior was examined through mechanical testing, computer modeling and analytic expressions. Existing assumptions about the foam characteristics that define the elastic properties were expanded to include contributions of axial and shear deformations in addition to bending and were rewritten in terms of the axial and bending stiffness ratios of ligaments. Compressive and tensile tests were performed to gain a measure of the elastic properties of the foam as well as the behavior and failure mechanisms in both loading conditions. The materials used …

Material Characterization And Structural Response Of Historic Truss Bridges, Sean L. Kelton

Masters Theses 1911 - February 2014

Historic truss bridges are examined in this thesis through material characterization of wrought iron and structural evaluation of an early 20th century pony truss bridge. The mechanical properties of wrought iron from six 19th century truss bridges were evaluated through mechanical testing that includes hardness and tension tests. The main findings of this work are: 1) That hardness is a poor predictor of yield and ultimate stress but has some ability in screening iron for iron with low ductility, 2) there is a statistically significant difference in the distribution of yield and ultimate stresses between material samples from different bridges, …

Investigation Of 3-D Heat Transfer Effects In Fenestration Products, Sneh Kumar

Masters Theses 1911 - February 2014

Buildings in USA consume close to 40% of overall energy used and fenestration products (e.g. windows, doors, glazed-wall etc.) are the largest components of energy loss from buildings. Accurate evaluation of thermal performances of fenestration systems is critical in predicting the overall building energy use, and improving the product performance. Typically, two-dimensional (2-D) heat transfer analysis is used to evaluate their thermal performance as the 3-D analysis is highly complex process requiring significantly more time, effort, and cost compared to 2-D analysis. Another method of evaluation e.g. physical test in a hotbox is not possible for each product as they …

Advanced Blade Testing Methods For Wind Turbines, Puneet Malhotra

Masters Theses 1911 - February 2014

This thesis consists of a detailed analysis of different blade testing methods and improvements to a novel concept for tri-axial testing of large wind turbine blades. As the blades are one of the most critical components of the wind turbine, they have to be tested in order to ensure that their specifications are consistent with the actual performance of the blade. It must be demonstrated that the blade can withstand both the ultimate loads and the fatigue loads to which the blade is expected to be subjected during its design service life. There are basically two types of blade testing: …

Route Choice Behavior In A Driving Simulator With Real-Time Information, Hengliang Tian

Masters Theses 1911 - February 2014

This research studies travelers' route choice behavior in a driving simulator with real-time information en-route. We investigate whether travelers plan strategically for real-time information en-route or simply select a fixed path from origin to destination at the beginning of a trip, and whether network complexity and a parallel driving task affect subjects' strategic thinking ability. In this study, strategic thinking refers to a traveler's route choice decision taking into account future diversion possibilities downstream enabled by information at the diversion node. All of the subjects in this study participated in driving-simulator-based tests while half of the subjects participated in additional …

Data Fusion For The Problem Of Protein Sidechain Assignment, Yang Lei

Masters Theses 1911 - February 2014

In this thesis, we study the problem of protein side chain assignment (SCA) given

multiple sources of experimental and modeling data. In particular, the mechanism

of X-ray crystallography (X-ray) is re-examined using Fourier analysis, and a novel

probabilistic model of X-ray is proposed for SCA's decision making. The relationship

between the measurements in X-ray and the desired structure is reformulated in terms

of Discrete Fourier Transform (DFT). The decision making is performed by developing

a new resolution-dependent electron density map (EDM) model and applying

Maximum Likelihood (ML) estimation, which simply reduces to the Least Squares

(LS) solution. Calculation of the …

Earthquake Engineering Simulation With Flexible Cladding System, Jun Jie Li

Masters Theses 1911 - February 2014

This research investigates the interaction between heavy precast cladding units attached to steel framed buildings. Cladding systems are designed as non-structural components and are not expected to contribute to the energy absorption of the primary structure. However, research has indicated that the cladding system may be designed to reduce the response of the primary structure under seismic excitations. The use of flexible connections between the cladding and primary structural frames may be able to provide beneficial effects to the entire structural response. In this study, a series of earthquake engineering simulations were conducted in OPENSEES to analyze the effects of …

The Impact Of Flexibility And Capacity Allocation On The Performance Of Primary Care Practices, Liang Wang

Masters Theses 1911 - February 2014

The two important metrics for any primary care practice are: (1) Timely Access and (2) Patient-physician Continuity. Timely access focuses on the ability of a patient to get access to a physician as soon as possible. Patient-physician continuity refers to building a strong or permanent relationship between a patient and a specific physician by maximizing patient visits to that physician. In the past decade, a new paradigm called advanced access or open access has been adopted by practices nationwide to encourage physician to “do today’s work today.” However, most clinics still reserve pre-scheduled appointments for long lead-time appointments due to …

Electric Power Market Modeling With Multi-Agent Reinforcement Learning, Nathanael K. Miksis

Masters Theses 1911 - February 2014

Agent-based modeling (ABM) is a relatively new tool for use in electric power market research. At heart are software agents representing real-world stakeholders in the industry: utilities, power producers, system operators, and regulators. Agents interact in an environment modeled after the real-world market and underlying physical infrastructure of modern power systems. Robust simulation laboratories will allow interested parties to stress test regulatory changes with agents motivated and able to exploit any weaknesses, before making these changes in the real world. Eventually ABM may help develop better understandings of electric market economic dynamics, clarifying both delineations and practical implications of market …

Terahertz And Microwave Detection Using Metallic Single Wall Carbon Nanotubes, Enrique A. Carrion

Masters Theses 1911 - February 2014

Carbon nanotubes (CNTs) are promising nanomaterials for high frequency applications due to their unique physical characteristics. CNTs have a low heat capacity, low intrinsic capacitance, and incredibly fast thermal time constants. They can also exhibit ballistic transport at low bias, for both phonons and electrons, as evident by their fairly long mean free paths. However, despite the great potential they present, the RF behavior of these nanostructures is not completely understood. In order to explore this high frequency regime we studied the microwave (MW) and terahertz (THz) response of individual and bundled single wall nanotube based devices. This thesis is …