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Process Planning For Rapid Manufacturing Of Plastic Injection Mold For Short Run Production, Rajesh Kumar Karthikeyan 2010 Iowa State University

Process Planning For Rapid Manufacturing Of Plastic Injection Mold For Short Run Production, Rajesh Kumar Karthikeyan

Graduate Theses and Dissertations

This thesis presents a process planning methodology for a rapid injection mold tool manufacturing system that involves additive and subtractive techniques, whereby slabs are sequentially bonded and milled using layered tool paths. Mold tools are grown in a bottom up fashion, eliminating the need for multi-axis machining operations (beyond three axes) and allowing small features in deep cavities. In this research, a new layer bonding method using friction stir welding of aluminum plates is presented. In this manner, one can create seam-free laminated aluminum injection mold tooling using a unique combination of industrial adhesives and friction stir spot welding to ...


Influence Of Post-Consumer Recycled Asphalt Shingles On Hot Mix Asphalt Containing Fractionated Recycled Asphalt Pavement, Andrew Aaron Cascione 2010 Iowa State University

Influence Of Post-Consumer Recycled Asphalt Shingles On Hot Mix Asphalt Containing Fractionated Recycled Asphalt Pavement, Andrew Aaron Cascione

Graduate Theses and Dissertations

As the cost of construction materials continue to rise and place financial constraints on transportation agencies, engineers are looking for sustainable methods that minimize construction costs and optimize the selection of materials used in asphalt pavements. Two methods that are beginning to receive considerable attention for highway construction are adding post-consumer recycled asphalt shingles (RAS) to hot mix asphalt (HMA) and increasing the percentage of recycled asphalt pavement being added to HMA through the process of fractionation.

The objective of this research is to characterize the effects of post-consumer RAS on the laboratory performance of HMA and its compatibility with ...


Discovering Patterns In A Survey Of Secondary Injuries Due To Agricultural Assistive Technology, Yanjun Shi 2010 Iowa State University

Discovering Patterns In A Survey Of Secondary Injuries Due To Agricultural Assistive Technology, Yanjun Shi

Graduate Theses and Dissertations

The research is motivated by the need for hazard assessment in agriculture field. A small and highly-imbalanced dataset, in which negative instances heavily outnumber positive instances, is derived from a survey of secondary injuries induced by implementation of agriculture assistive technology which assists farmers with injuries or disabilities to continue farm-related work. Three data mining approaches are applied to the imbalanced dataset in order to discover patterns contributing to secondary injuries.

All of patterns discovered by the three approaches are compared according to three evaluation measurements: support, confidence and lift, and potentially most interesting patterns are found. Compared to graphical ...


Reducing Phase Noise Degradation Due To Vibration Of Crystal Oscillators, Cory Nelson 2010 Iowa State University

Reducing Phase Noise Degradation Due To Vibration Of Crystal Oscillators, Cory Nelson

Graduate Theses and Dissertations

In the radio communications industry, one major problem is the vibration induced on to a frequency standard. The most commonly used frequency standard is the crystal oscillator; as the crystal oscillator gets vibrated with varying force and frequencies of vibration the phase noise of the signal changes. As the phase noise increases, the signal to noise ratio decreases causing the likelihood of transmitting or receiving an incorrect signal to rise. This makes it critical to limit the phase noise increase that occurs in the frequency standard of the system.

Mechanical isolation systems have been implemented in the industry to limit ...


Corncob Dry Matter Loss In Storage As Affected By Temperature And Moisture Content, Bernardo Gusman Del Campo 2010 Iowa State University

Corncob Dry Matter Loss In Storage As Affected By Temperature And Moisture Content, Bernardo Gusman Del Campo

Graduate Theses and Dissertations

Agricultural residues, like corn cobs, are one of the first promising cellulosic materials to be fermented and thermochemically processed into fuel in the emerging bio-based economy. Few studies have been conducted on the deterioration of cellulosic feedstock in storage. This study measured the loss of corn cob dry matter, as measured by carbon dioxide evolution, under various storage conditions (temperature and moisture content) for 21 days. High moisture content and temperature conditions (35% w.b. and 30yC) resulted in almost 3 % dry matter loss in 21days, as opposed to negligible losses at drier conditions (15% w.b.). There was a ...


Mining Frequent Generalized Patterns For Web Personalization In The Presence Of Taxonomies, P. Giannikopoulos, I. Varlamis, Magdalini Eirinaki 2010 University of Peloponnese, Greece

Mining Frequent Generalized Patterns For Web Personalization In The Presence Of Taxonomies, P. Giannikopoulos, I. Varlamis, Magdalini Eirinaki

Faculty Publications

The Web is a continuously evolving environment, since its content is updated on a regular basis. As a result, the traditional usage-based approach to generate recommendations that takes as input the navigation paths recorded on the Web page level, is not as effective. Moreover, most of the content available online is either explicitly or implicitly characterized by a set of categories organized in a taxonomy, allowing the page-level navigation patterns to be generalized to a higher, aggregate level. In this direction, the authors present the Frequent Generalized Pattern (FGP) algorithm. FGP takes as input the transaction data and a hierarchy ...


Incentive Mechanisms In P2p Media Streaming Systems, Xiao Su, Suchreet Dhaliwal 2010 San Jose State University

Incentive Mechanisms In P2p Media Streaming Systems, Xiao Su, Suchreet Dhaliwal

Faculty Publications

This paper highlights the need to curb free-riding in P2P media streaming systems and discusses the mechanisms by which this could be accomplished. Free riding, whereby a peer utilizes network resources, but does not contribute services could have a huge impact on the efficacy of blue streaming systems, leading to scalability issues and service degradation. We discuss why BitTorrent-like tit-for-tat mechanisms cannot be simply tailored and used in streaming. Even though the problem of free riding is more severe in P2P media streaming than in file sharing, the deployed systems still lack incentive schemes. In this paper, we categorize, analyze ...


Approaches To Multiprocessor Error Recovery Using An On-Chip Interconnect Subsystem, Ramakrishna P. Vadlamani 2010 University of Massachusetts Amherst

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 2010 University of Massachusetts Amherst

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 ...


Sorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song 2010 University of Massachusetts Amherst

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 ...


A Quantitative Analysis Of The Impacts From Selected Variables Upon Safety Belt Usage In Massachusetts, Samuel W. Gregorio 2010 University of Massachusetts Amherst

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 ...


Fast Parameter-Space Sweep Of Wideband Electromagnetic Systems Using Bt-Pod, Wei Wang 2010 University of Massachusetts Amherst

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 ...


Scalable, Memory-Intensive Scientific Computing On Field Programmable Gate Arrays, Salma Mirza 2010 University of Massachusetts Amherst

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 ...


Optical Lithography Simulation Using Wavelet Transform, Rance Rodrigues 2010 University of Massachusetts Amherst

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 2010 University of Massachusetts Amherst

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 2010 University of Massachusetts Amherst

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 ...


Efficient Modeling Techniques For Time-Dependent Quantum System With Applications To Carbon Nanotubes, Zuojing Chen 2010 University of Massachusetts Amherst

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 ...


Investigation Of The Behavior Of Open Cell Aluminum Foam, Patrick J. Veale 2010 University of Massachusetts Amherst

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 ...


Terahertz And Microwave Detection Using Metallic Single Wall Carbon Nanotubes, Enrique A. Carrion 2010 University of Massachusetts Amherst

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 ...


Data Fusion For The Problem Of Protein Sidechain Assignment, Yang Lei 2010 University of Massachusetts Amherst

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 ...


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