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2010

University of Massachusetts Amherst

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Articles 31 - 60 of 88

Full-Text Articles in Engineering

A Multiscale Model To Investigate Circadian Rhythmicity Of Pacemaker Neurons In The Suprachiasmatic Nucleus, Christina Vasalou, Michael A. Henson Mar 2010

A Multiscale Model To Investigate Circadian Rhythmicity Of Pacemaker Neurons In The Suprachiasmatic Nucleus, Christina Vasalou, Michael A. Henson

Michael A Henson

The suprachiasmatic nucleus (SCN) of the hypothalamus is a multicellular system that drives daily rhythms in mammalian behavior and physiology. Although the gene regulatory network that produces daily oscillations within individual neurons is well characterized, less is known about the electrophysiology of the SCN cells and how firing rate correlates with circadian gene expression. We developed a firing rate code model to incorporate known electrophysiological properties of SCN pacemaker cells, including circadian dependent changes in membrane voltage and ion conductances. Calcium dynamics were included in the model as the putative link between electrical firing and gene expression. Individual ion currents …


Expanding Ethics Education In Science & Engineering, Jane E. Fountain Feb 2010

Expanding Ethics Education In Science & Engineering, Jane E. Fountain

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …


Nsf Supported Case-Studies Done By Systems Engineering Graduate Students At Uva, Michael Gorman Feb 2010

Nsf Supported Case-Studies Done By Systems Engineering Graduate Students At Uva, Michael Gorman

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …


Science And Engineering Ethics Education: Recipes For Success, Philip J. Langlais Feb 2010

Science And Engineering Ethics Education: Recipes For Success, Philip J. Langlais

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …


Rcr For Postdocs: Promoting Ethical Professional Development, Kathleen Flint Feb 2010

Rcr For Postdocs: Promoting Ethical Professional Development, Kathleen Flint

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …


Update On Responsible Conduct Of Research, Michael E. Gorman, Kelly Joyce Feb 2010

Update On Responsible Conduct Of Research, Michael E. Gorman, Kelly Joyce

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …


A Hardware/Software Co-Design Architecture For Thermal, Power, And Reliability Management In Chip Multiprocessors, Omer Khan Feb 2010

A Hardware/Software Co-Design Architecture For Thermal, Power, And Reliability Management In Chip Multiprocessors, Omer Khan

Open Access Dissertations

Today’s designs are being shaped by the challenges of nano-CMOS technologies: increased power density, rising junction temperatures, and rising rate of errors and device failures that constrain average rate of power dissipation, and design technologies that limit peak power delivery. This thesis focuses on how to leverage the hardware and software abstraction layers of today’s systems. Several of the low level hardware details such as power, hotspots, and faults are tightly correlated to interactions within the system including application and hardware behavior. The conventional approach to tackling such problems come with additional costs and design complexity, and they are limited …


Polymer Composites And Porous Materials Prepared By Thermally Induced Phase Separation And Polymer-Metal Hybrid Methods, Joonsung Yoon Feb 2010

Polymer Composites And Porous Materials Prepared By Thermally Induced Phase Separation And Polymer-Metal Hybrid Methods, Joonsung Yoon

Open Access Dissertations

The primary objective of this research is to investigate the morphological and mechanical properties of composite materials and porous materials prepared by thermally induced phase separation. High melting crystallizable diluents were mixed with polymers so that the phase separation would be induced by the solidification of the diluents upon cooling. Theoretical phase diagrams were calculated using Flory-Huggins solution thermodynamics which show good agreement with the experimental results. Porous materials were prepared by the extraction of the crystallized diluents after cooling the mixtures (hexamethylbenzene/polyethylene and pyrene/polyethylene). Anisotropic structures show strong dependence on the identity of the diluents and the composition of …


Quantifying Defects In Zeolites And Zeolite Membranes, Karl Daniel Hammond Feb 2010

Quantifying Defects In Zeolites And Zeolite Membranes, Karl Daniel Hammond

Open Access Dissertations

Zeolites are crystalline aluminosilicates that are frequently used as catalysts to transform chemical feedstocks into more useful materials in a size- or shape-selective fashion; they are one of the earliest forms of nanotechnology. Zeolites can also be used, especially in the form of zeolite membranes (layers of zeolite on a support), to separate mixtures based on the size of the molecules. Recent advances have also created the possibility of using zeolites as alkaline catalysts, in addition to their traditional applications as acid catalysts and catalytic supports. Transport and catalysis in zeolites are greatly affected by physical and chemical defects. Such …


Water-In-Oil Microemulsions: Counterion Effects In Aot Systems And New Fluorocarbon-Based Microemulsion Gels, Xiaoming Pan Feb 2010

Water-In-Oil Microemulsions: Counterion Effects In Aot Systems And New Fluorocarbon-Based Microemulsion Gels, Xiaoming Pan

Open Access Dissertations

Microemulsions have important applications in various industries, including enhanced oil recovery, reactions, separations, drug delivery, cosmetics and foods. We investigated two different kinds of water-in-oil microemulsion systems, AOT (bis(2-ethylhexyl) sulfosuccinate) microemulsions with various counterions and perfluorocarbon-based microemulsion gels with triblock copolymers. In the AOT systems, we investigated the viscosity and interdroplet interactions in Ca(AOT)2, Mg(AOT)2 and KAOT microemulsions, and compared our results with the commonly-studied NaAOT/water/decane system. We attribute the differences in behavior to different hydration characteristics of the counterions, and we believe that the results are consistent with a previously proposed charge fluctuation model. Perfluorocarbons (PFCs) are of interest …


Modeling Of Thermal Non-Equilibrium In Superheated Injector Flows, Shivasubramanian Gopalakrishnan Feb 2010

Modeling Of Thermal Non-Equilibrium In Superheated Injector Flows, Shivasubramanian Gopalakrishnan

Open Access Dissertations

Among the many factors that effect the atomization of a fuel spray in a com- bustion chamber, the flow characteristics of the fuel inside the injector nozzle play significant roles. The enthalpy of the entering fuel can be elevated such that it is higher than the local or downstream saturation enthalpy, which will result in the flash-boiling of the liquid. The phase change process dramatically effects the flow rate and has the potential to cause subsonic two-phase choking. The timescale over which this occurs is comparable to the flow-through time of the nozzle and hence any attempt to model this …


Protocol And System Design For A Service-Centric Network Architecture, Xin Huang Feb 2010

Protocol And System Design For A Service-Centric Network Architecture, Xin Huang

Open Access Dissertations

Next-generation Internet will be governed by the need for flexibility. Heterogeneous end-systems, novel applications, and security and manageability challenges require networks to provide a broad range of services that go beyond store-and-forward. Following this trend, a service-centric network architecture is proposed for the next-generation Internet. It utilizes router-based programmability to provide packet processing services inside the network and decompose communications into these service blocks. By providing different compositions of services along the data path, such network can customize its connections to satisfy various communication requirements. This design extends the flexibility of the Internet to meet its next-generation challenges. This work …


Evaluating Alternative Public-Private Partnership Strategies For Existing Toll Roads: Toward The Development Of A Decision Support System, Christopher John Ahmadjian Feb 2010

Evaluating Alternative Public-Private Partnership Strategies For Existing Toll Roads: Toward The Development Of A Decision Support System, Christopher John Ahmadjian

Open Access Dissertations

Many claim that, with regard to transportation infrastructure, only partnerships between public and private entities, which draw on the strengths of both, can achieve the goals of enhancing operational efficiency, increasing service delivery, improving asset maintenance, and stretching scarce federal, state, and local tax dollars. While some completed public-private partnership (P3) agreements on existing toll roads in the United States have seen a measure of success, others have raised critical questions pertaining to the true costs and benefits associated with these agreements for all stakeholders. Of particular concern is an apparent reliance on monetary calculations alone to determine toll road …


The Performance Of Wind Turbine Smart Rotor Control Approaches During Extreme Loads, Matthew Lackner, Gijs A. M. Van Kuik Feb 2010

The Performance Of Wind Turbine Smart Rotor Control Approaches During Extreme Loads, Matthew Lackner, Gijs A. M. Van Kuik

Matthew Lackner

Reducing the loads experienced by wind turbine rotor blades can lower the cost of energy of wind turbines. “Smart rotor control” concepts have emerged as a solution to reduce fatigue loads on wind turbines. In this approach, aerodynamic load control devices are distributed along the span of the blade, and through a combination of sensing, control, and actuation, these devices dynamically control the blade loads. While smart rotor control approaches are primarily focused on fatigue load reductions, extreme loads on the blades may also be critical in determining the lifetime of components, and the ability to reduce these loads as …


A Comprehensive Study Of The Extensional Rheology Of Complex Fluids, Manojkumar Chellamuthu Feb 2010

A Comprehensive Study Of The Extensional Rheology Of Complex Fluids, Manojkumar Chellamuthu

Doctoral Dissertations 1896 - February 2014

Non-Newtonian fluids play an important role in our daily life. The visco-elastic nature of these fluids comprises a class of materials found in variety of items ranging from food, to plastic products, to the cosmetic products. The design and tunability of non-Newtonian fluids is only possible through an understanding of their complex dynamics and rheology. In this thesis, a filament stretching rheometer is used to investigate the extensional rheology of three important classes of complex visco-elastic fluids namely surfactants, suspensions and polymers.

Surfactants with their unique molecular amphiphilic chemistry allow them to form long wormlike micellar structures, which behave like …


Floornet: Deployment And Evaluation Of Amultihop Wireless 802.11 Testbed, Pablo Serrano, Carlos J. Bernardos, Antonio De La Oliva, Albert Banchs, Ignacio Soto, Michael Zink Jan 2010

Floornet: Deployment And Evaluation Of Amultihop Wireless 802.11 Testbed, Pablo Serrano, Carlos J. Bernardos, Antonio De La Oliva, Albert Banchs, Ignacio Soto, Michael Zink

Michael Zink

A lot of attention has been given to multihop wireless networks lately, but further research—in particular, through experimentation—is needed. This attention has motivated an increase in the number of 802.11-based deployments, both indoor and outdoor. These testbeds, which require a significant amount of resources during both deployment and maintenance, are used to run measurements in order to analyze and understand the limitation and differences between analytical or simulation-based figures and the results from real-life experimentation. This paper makes two major contributions: (i) first, we describe a novel wireless multihop testbed, which we name FloorNet, that is deployed and operated under …


My Italian Connections: Otto Vogl In Italy, Otto Vogl, Gerald S. Kirshenbaum Jan 2010

My Italian Connections: Otto Vogl In Italy, Otto Vogl, Gerald S. Kirshenbaum

Emeritus Faculty Author Gallery

This document describes Otto Vogl's work in Italy. From 1975, Vogl served for 3 years as the Chairman of the Scientific Advisory Committee to the President Italo Trapasso of the Plastic Materials Company of Montedison SA, Milan, Italy. He was assigned to restructure the research activities and to organize the Research Division. He was responsible for the appointment of DiDrusco as the Vice President of Research and Paolo Galli as the Director of Research at the company’s facilities in Ferrara. Within a year of Vogl’s reorganization of the research organization the high yield catalyst for the polymerization of propylene was …


Anhang: Auszüge Aus Dem Späteren Leben Von Professor Dr. Otto Vogl, Otto Vogl Jan 2010

Anhang: Auszüge Aus Dem Späteren Leben Von Professor Dr. Otto Vogl, Otto Vogl

Emeritus Faculty Author Gallery

No abstract provided.


Post Silicon Clock Tuning System To Mitigate The Impact Of Process Variation On Performance, Kelageri Nagaraj Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 Jan 2010

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 …