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- All Subjects: Guitar music
ContributorsDaval, Charles (Performer) / ASU Library. Music Library (Publisher)
Created2018-03-26
DescriptionThe purpose of this project is to explore the influence of folk music in guitar compositions by Manuel Ponce from 1923 to 1932. It focuses on his Tres canciones populares mexicanas and Tropico and Rumba.
ContributorsGarcia Santos, Arnoldo (Author) / Koonce, Frank (Thesis advisor) / Rogers, Rodney (Committee member) / Rotaru, Catalin (Committee member) / Arizona State University (Publisher)
Created2014
Description
Thin films of ever reducing thickness are used in a plethora of applications and their performance is highly dependent on their microstructure. Computer simulations could then play a vital role in predicting the microstructure of thin films as a function of processing conditions. FACET is one such software tool designed by our research group to model polycrystalline thin film growth, including texture evolution and grain growth of polycrystalline films in 2D. Several modifications to the original FACET code were done to enhance its usability and accuracy. Simulations of sputtered silver thin films are presented here with FACET 2.0 with qualitative and semi-quantitative comparisons with previously published experimental results. Comparisons of grain size, texture and film thickness between simulations and experiments are presented which describe growth modes due to various deposition factors like flux angle and substrate temperature. These simulations provide reasonable agreement with the experimental data over a diverse range of process parameters. Preliminary experiments in depositions of Silver films are also attempted with varying substrates and thickness in order to generate complementary experimental and simulation studies of microstructure evolution. Overall, based on the comparisons, FACET provides interesting insights into thin film growth processes, and the effects of various deposition conditions on thin film structure and microstructure. Lastly, simple molecular dynamics simulations of deposition on bi-crystals are attempted for gaining insight into texture based grain competition during film growth. These simulations predict texture based grain coarsening mechanisms like twinning and grain boundary migration that have been commonly reported in FCC films.
ContributorsRairkar, Asit (Author) / Adams, James B (Thesis advisor) / Krause, Stephen (Committee member) / Alford, Terry (Committee member) / Arizona State University (Publisher)
Created2011
Description
The drive towards device scaling and large output power in millimeter and sub-millimeter wave power amplifiers results in a highly non-linear, out-of-equilibrium charge transport regime. Particle-based Full Band Monte Carlo device simulators allow an accurate description of this carrier dynamics at the nanoscale. This work initially compares GaN high electron mobility transistors (HEMTs) based on the established Ga-face technology and the emerging N-face technology, through a modeling approach that allows a fair comparison, indicating that the N-face devices exhibit improved performance with respect to Ga-face ones due to the natural back-barrier confinement that mitigates short-channel-effects. An investigation is then carried out on the minimum aspect ratio (i.e. gate length to gate-to-channel-distance ratio) that limits short channel effects in ultra-scaled GaN and InP HEMTs, indicating that this value in GaN devices is 15 while in InP devices is 7.5. This difference is believed to be related to the different dielectric properties of the two materials, and the corresponding different electric field distributions. The dielectric effects of the passivation layer in millimeter-wave, high-power GaN HEMTs are also investigated, finding that the effective gate length is increased by fringing capacitances, enhanced by the dielectrics in regions adjacent to the gate for layers thicker than 5 nm, strongly affecting the frequency performance of deep sub-micron devices. Lastly, efficient Full Band Monte Carlo particle-based device simulations of the large-signal performance of mm-wave transistor power amplifiers with high-Q matching networks are reported for the first time. In particular, a CellularMonte Carlo (CMC) code is self-consistently coupled with a Harmonic Balance (HB) frequency domain circuit solver. Due to the iterative nature of the HB algorithm, this simulation approach is possible only due to the computational efficiency of the CMC, which uses pre-computed scattering tables. On the other hand, HB allows the direct simulation of the steady-state behavior of circuits with long transient time. This work provides an accurate and efficient tool for the device early-stage design, which allows a computerbased performance evaluation in lieu of the extremely time-consuming and expensive iterations of prototyping and experimental large-signal characterization.
ContributorsGuerra, Diego (Author) / Saraniti, Marco (Thesis advisor) / Ferry, David K. (Committee member) / Goodnick, Stephen M (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2011
ContributorsKotronakis, Dimitris (Performer) / ASU Library. Music Library (Publisher)
Created2018-03-01
Description
This paper details the specification and implementation of a single-machine blockchain simulator. It also includes a brief introduction on the history & underlying concepts of blockchain, with explanations on features such as decentralization, openness, trustlessness, and consensus. The introduction features a brief overview of public interest and current implementations of blockchain before stating potential use cases for blockchain simulation software. The paper then gives a brief literature review of blockchain's role, both as a disruptive technology and a foundational technology. The literature review also addresses the potential and difficulties regarding the use of blockchain in Internet of Things (IoT) networks, and also describes the limitations of blockchain in general regarding computational intensity, storage capacity, and network architecture. Next, the paper gives the specification for a generic blockchain structure, with summaries on the behaviors and purposes of transactions, blocks, nodes, miners, public & private key cryptography, signature validation, and hashing. Finally, the author gives an overview of their specific implementation of the blockchain using C/C++ and OpenSSL. The overview includes a brief description of all the classes and data structures involved in the implementation, including their function and behavior. While the implementation meets the requirements set forward in the specification, the results are more qualitative and intuitive, as time constraints did not allow for quantitative measurements of the network simulation. The paper concludes by discussing potential applications for the simulator, and the possibility for future hardware implementations of blockchain.
ContributorsRauschenbach, Timothy Rex (Author) / Vrudhula, Sarma (Thesis director) / Nakamura, Mutsumi (Committee member) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Financial statements are one of the most important, if not the most important, documents for investors. These statements are prepared quarterly and yearly by the company accounting department, and are then audited in detail by a large external accounting firm. Investors use these documents to determine the value of the company, and trust that the company was truthful in its statements, and the auditing firm correctly audited the company's financial statements for any mistakes in their books and balances. Mistakes on a company's financial statements can be costly. However, financial fraud on the statements can be outright disastrous. Penalties for accounting fraud can include individual lifetime prison sentences, as well as company fines for billions of dollars. As students in the accounting major, it is our responsibility to ensure that financial statements are accurate and truthful to protect ourselves, other stakeholders, and the companies we work for. This ethics game takes the stories of Enron, WorldCom, and Lehman Brothers and uses them to help students identify financial fraud and how it can be prevented, as well as the consequences behind unethical decisions in financial reporting. The Enron scandal involved CEO Kenneth Lay and his predecessor Jeffery Skilling hiding losses in their financial statements with the help of their auditing firm, Arthur Andersen. Enron collapsed in 2002, and Lay was sentenced to 45 years in prison with his conspirator Skilling sentenced to 24 years in prison. In the WorldCom scandal, CEO Bernard "Bernie" Ebbers booked line costs as capital expenses (overstating WorldCom's assets), and created fraudulent accounts to inflate revenue and WorldCom's profit. Ebbers was sentenced to 25 years in prison and lost his title as WorldCom's Chief Executive Officer. Lehman Brothers took advantage of a loophole in accounting procedure Repo 105, that let the firm hide $50 billion in profits. No one at Lehman Brothers was sentenced to jail since the transaction was technically considered legal, but Lehman was the largest investment bank to fail and the only large financial institution that was not bailed out by the U.S. government.
ContributorsPanikkar, Manoj Madhuraj (Author) / Samuelson, Melissa (Thesis director) / Ahmad, Altaf (Committee member) / Department of Information Systems (Contributor) / School of Accountancy (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Separation of carbon dioxide and methane for the upgrade of natural gas through use of pressure swing adsorption could potentially save large amounts of energy from the current, costly process of cryogenic distillation and provides greater cost effectiveness for carbon dioxide capture, and provide larger product flowrates than membrane permeation separation. The purpose of this study is to analyze the effects of varying initial conditions of a MatLab simulation, courtesy of Mai Xu, a graduate student at ASU, designed to use Langmuir isotherms, mass transfer equations, and adsorbent and gas properties to simulate a pressure swing adsorption process with a mixture of methane and carbon dioxide gas feed. The effects that will be varied are the adsorption/desorption time, pressurization/depressurization time, adsorption feed composition, desorption purge composition, adsorption pressure, desorption pressure, adsorption flow rate, and desorption flow rate. The study found that the trends in methane purity and production generally follow the trends predicted by literature and relevant equations, with pressure boundaries being the largest impacting factor. In addition there was a markedly inverse correlation between purity of methane product and the productivity of the system. This trend was only violated in one instance, at very low vacuum pressure during desorption, which could indicate an area that requires further study. Overall, the main areas of improvement in pressure swing adsorption for this system would be improving the selectivity of adsorption of carbon dioxide over methane, which requires improvement and change of the adsorbent, and more extreme vacuum pressures during desorption, both of which will increase methane yield and reduce operating costs.
ContributorsCook, Alexander Charles (Author) / Deng, Shuguang (Thesis director) / Mu, Bin (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The current Enterprise Requirements and Acquisition Model (ERAM), a discrete event simulation of the major tasks and decisions within the DoD acquisition system, identifies several what-if intervention strategies to improve program completion time. However, processes that contribute to the program acquisition completion time were not explicitly identified in the simulation study. This research seeks to determine the acquisition processes that contribute significantly to total simulated program time in the acquisition system for all programs reaching Milestone C. Specifically, this research examines the effect of increased scope management, technology maturity, and decreased variation and mean process times in post-Design Readiness Review contractor activities by performing additional simulation analyses. Potential policies are formulated from the results to further improve program acquisition completion time.
ContributorsWorger, Danielle Marie (Author) / Wu, Teresa (Thesis director) / Shunk, Dan (Committee member) / Wirthlin, J. Robert (Committee member) / Industrial, Systems (Contributor) / Barrett, The Honors College (Contributor)
Created2013-05
Description
As technologies advance, so does the curiosity and exploration of humankind. There are many domains across this planet that are unexplored \u2014 the depths of Earth's ocean being one of the most predominant. While the ocean covers seventy percent of Earth's surface, a vast ninety-five percent of this realm remains untouched and unseen by the human eye. The biggest causality of this can be identified in the limitations of current technologies and the large expense associated with delving into these dangerous and uncharted areas. Underwater communication between unmanned devices is the solution to this problem. With the oceanic deployment of wirelessly connected unmanned underwater vehicles (UUVs), researchers can limit risk to human safely and retrieve invaluable oceanographic data from unimaginable depths. However, before this system can be physically deployed, the network topology and environmental interactions must be simulated. More specific to the application, how does attenuation of optical propagation degrade between transmissions? A widely used open source network simulator is the ns series: ns-1, ns-2, and ns-3. Ns-3 is the most recent version, and is a valuable tool for modeling network interactions. However, underwater simulation proposes a limitation \u2014 a three-dimensional consideration for pressure. To properly model this interaction, it is vital that an extension to ns-3 be provided in order to account for the affects pressure has on the propagation of a signal at varying depths.
ContributorsSowa, Ryan John (Author) / Richa, Andrea (Thesis director) / Saripalli, Srikanth (Committee member) / Zhou, Chenyang (Committee member) / Barrett, The Honors College (Contributor) / Computer Science and Engineering Program (Contributor)
Created2013-05