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Description
Signal processing techniques have been used extensively in many engineering problems and in recent years its application has extended to non-traditional research fields such as biological systems. Many of these applications require extraction of a signal or parameter of interest from degraded measurements. One such application is mass spectrometry immunoassay (MSIA) which has been one of the primary methods of biomarker discovery techniques. MSIA analyzes protein molecules as potential biomarkers using time of flight mass spectrometry (TOF-MS). Peak detection in TOF-MS is important for biomarker analysis and many other MS related application. Though many peak detection algorithms exist, most of them are based on heuristics models. One of the ways of detecting signal peaks is by deploying stochastic models of the signal and noise observations. Likelihood ratio test (LRT) detector, based on the Neyman-Pearson (NP) lemma, is an uniformly most powerful test to decision making in the form of a hypothesis test. The primary goal of this dissertation is to develop signal and noise models for the electrospray ionization (ESI) TOF-MS data. A new method is proposed for developing the signal model by employing first principles calculations based on device physics and molecular properties. The noise model is developed by analyzing MS data from careful experiments in the ESI mass spectrometer. A non-flat baseline in MS data is common. The reasons behind the formation of this baseline has not been fully comprehended. A new signal model explaining the presence of baseline is proposed, though detailed experiments are needed to further substantiate the model assumptions. Signal detection schemes based on these signal and noise models are proposed. A maximum likelihood (ML) method is introduced for estimating the signal peak amplitudes. The performance of the detection methods and ML estimation are evaluated with Monte Carlo simulation which shows promising results. An application of these methods is proposed for fractional abundance calculation for biomarker analysis, which is mathematically robust and fundamentally different than the current algorithms. Biomarker panels for type 2 diabetes and cardiovascular disease are analyzed using existing MS analysis algorithms. Finally, a support vector machine based multi-classification algorithm is developed for evaluating the biomarkers' effectiveness in discriminating type 2 diabetes and cardiovascular diseases and is shown to perform better than a linear discriminant analysis based classifier.
ContributorsBuddi, Sai (Author) / Taylor, Thomas (Thesis advisor) / Cochran, Douglas (Thesis advisor) / Nelson, Randall (Committee member) / Duman, Tolga (Committee member) / Arizona State University (Publisher)
Created2012
Description
Immunosignaturing is a new immunodiagnostic technology that uses random-sequence peptide microarrays to profile the humoral immune response. Though the peptides have little sequence homology to any known protein, binding of serum antibodies may be detected, and the pattern correlated to disease states. The aim of my dissertation is to analyze the factors affecting the binding patterns using monoclonal antibodies and determine how much information may be extracted from the sequences. Specifically, I examined the effects of antibody concentration, competition, peptide density, and antibody valence. Peptide binding could be detected at the low concentrations relevant to immunosignaturing, and a monoclonal's signature could even be detected in the presences of 100 fold excess naive IgG. I also found that peptide density was important, but this effect was not due to bivalent binding. Next, I examined in more detail how a polyreactive antibody binds to the random sequence peptides compared to protein sequence derived peptides, and found that it bound to many peptides from both sets, but with low apparent affinity. An in depth look at how the peptide physicochemical properties and sequence complexity revealed that there were some correlations with properties, but they were generally small and varied greatly between antibodies. However, on a limited diversity but larger peptide library, I found that sequence complexity was important for antibody binding. The redundancy on that library did enable the identification of specific sub-sequences recognized by an antibody. The current immunosignaturing platform has little repetition of sub-sequences, so I evaluated several methods to infer antibody epitopes. I found two methods that had modest prediction accuracy, and I developed a software application called GuiTope to facilitate the epitope prediction analysis. None of the methods had sufficient accuracy to identify an unknown antigen from a database. In conclusion, the characteristics of the immunosignaturing platform observed through monoclonal antibody experiments demonstrate its promise as a new diagnostic technology. However, a major limitation is the difficulty in connecting the signature back to the original antigen, though larger peptide libraries could facilitate these predictions.
ContributorsHalperin, Rebecca (Author) / Johnston, Stephen A. (Thesis advisor) / Bordner, Andrew (Committee member) / Taylor, Thomas (Committee member) / Stafford, Phillip (Committee member) / Arizona State University (Publisher)
Created2011
Description
This dissertation describes a novel, low cost strategy of using particle streak (track) images for accurate micro-channel velocity field mapping. It is shown that 2-dimensional, 2-component fields can be efficiently obtained using the spatial variation of particle track lengths in micro-channels. The velocity field is a critical performance feature of many microfluidic devices. Since it is often the case that un-modeled micro-scale physics frustrates principled design methodologies, particle based velocity field estimation is an essential design and validation tool. Current technologies that achieve this goal use particle constellation correlation strategies and rely heavily on costly, high-speed imaging hardware. The proposed image/ video processing based method achieves comparable accuracy for fraction of the cost. In the context of micro-channel velocimetry, the usability of particle streaks has been poorly studied so far. Their use has remained restricted mostly to bulk flow measurements and occasional ad-hoc uses in microfluidics. A second look at the usability of particle streak lengths in this work reveals that they can be efficiently used, after approximately 15 years from their first use for micro-channel velocimetry. Particle tracks in steady, smooth microfluidic flows is mathematically modeled and a framework for using experimentally observed particle track lengths for local velocity field estimation is introduced here, followed by algorithm implementation and quantitative verification. Further, experimental considerations and image processing techniques that can facilitate the proposed methods are also discussed in this dissertation. Unavailability of benchmarked particle track image data motivated the implementation of a simulation framework with the capability to generate exposure time controlled particle track image sequence for velocity vector fields. This dissertation also describes this work and shows that arbitrary velocity fields designed in computational fluid dynamics software tools can be used to obtain such images. Apart from aiding gold-standard data generation, such images would find use for quick microfluidic flow field visualization and help improve device designs.
ContributorsMahanti, Prasun (Author) / Cochran, Douglas (Thesis advisor) / Taylor, Thomas (Thesis advisor) / Hayes, Mark (Committee member) / Zhang, Junshan (Committee member) / Arizona State University (Publisher)
Created2011
Description
This thesis examines the application of statistical signal processing approaches to data arising from surveys intended to measure psychological and sociological phenomena underpinning human social dynamics. The use of signal processing methods for analysis of signals arising from measurement of social, biological, and other non-traditional phenomena has been an important and growing area of signal processing research over the past decade. Here, we explore the application of statistical modeling and signal processing concepts to data obtained from the Global Group Relations Project, specifically to understand and quantify the effects and interactions of social psychological factors related to intergroup conflicts. We use Bayesian networks to specify prospective models of conditional dependence. Bayesian networks are determined between social psychological factors and conflict variables, and modeled by directed acyclic graphs, while the significant interactions are modeled as conditional probabilities. Since the data are sparse and multi-dimensional, we regress Gaussian mixture models (GMMs) against the data to estimate the conditional probabilities of interest. The parameters of GMMs are estimated using the expectation-maximization (EM) algorithm. However, the EM algorithm may suffer from over-fitting problem due to the high dimensionality and limited observations entailed in this data set. Therefore, the Akaike information criterion (AIC) and the Bayesian information criterion (BIC) are used for GMM order estimation. To assist intuitive understanding of the interactions of social variables and the intergroup conflicts, we introduce a color-based visualization scheme. In this scheme, the intensities of colors are proportional to the conditional probabilities observed.
ContributorsLiu, Hui (Author) / Taylor, Thomas (Thesis advisor) / Cochran, Douglas (Thesis advisor) / Zhang, Junshan (Committee member) / Arizona State University (Publisher)
Created2012
Description
For as long as humans have been working, they have been looking for ways to get that work done better, faster, and more efficient. Over the course of human history, mankind has created innumerable spectacular inventions, all with the goal of making the economy and daily life more efficient. Today, innovations and technological advancements are happening at a pace like never seen before, and technology like automation and artificial intelligence are poised to once again fundamentally alter the way people live and work in society. Whether society is prepared or not, robots are coming to replace human labor, and they are coming fast. In many areas artificial intelligence has disrupted entire industries of the economy. As people continue to make advancements in artificial intelligence, more industries will be disturbed, more jobs will be lost, and entirely new industries and professions will be created in their wake. The future of the economy and society will be determined by how humans adapt to the rapid innovations that are taking place every single day. In this paper I will examine the extent to which automation will take the place of human labor in the future, project the potential effect of automation to future unemployment, and what individuals and society will need to do to adapt to keep pace with rapidly advancing technology. I will also look at the history of automation in the economy. For centuries humans have been advancing technology to make their everyday work more productive and efficient, and for centuries this has forced humans to adapt to the modern technology through things like training and education. The thesis will additionally examine the ways in which the U.S. education system will have to adapt to meet the demands of the advancing economy, and how job retraining programs must be modernized to prepare workers for the changing economy.
ContributorsCunningham, Reed P. (Author) / DeSerpa, Allan (Thesis director) / Haglin, Brett (Committee member) / School of International Letters and Cultures (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Nuclear weapons possess enormous potential to inflict damage on our world. The majority of countries in the world denounce the proliferation of these weapons, but a minority of countries have a desire to proliferate. This essay analyzes the impact of regime type and alliance strength to a nuclear state on protégé proliferation decisions. Prior research focuses on single factors in proliferation decisions and fails to take in to account the multi-faceted factors that influence the international system that states operate in. The analysis finds that regime type gives an indication about a state’s likelihood to proliferate, but does not explain proliferation choices comprehensively. Alliance strength plays a large role in a state’s security calculations and must be analyzed in conjunction to regime type to understand proliferation decisions.
ContributorsHsu, Kai Nalu (Author) / Wright, Thorin (Thesis director) / Thies, Cameron (Committee member) / W.P. Carey School of Business (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
#VanLife is a long-time, up and coming lifestyle movement on social media centered around the process of leaving the traditional nine-to-five work week for a life on the road in a camper van. While the ‘hippie-esque’ vagabond lifestyle has its humble roots long before the turn of the century, the inception of social media platforms such as Instagram and Pinterest have fueled the more recent popularization of a full-time life on the road. #VanLifers often freelance on the road, work part time jobs, or gain sponsorships to help fund their traveling and humble lifestyle.
As the #VanLife craze continues to grow, new businesses are finding ways to meet the demand in the market. For #Vanlifers who own and operate their own camper vans, specialized companies like GoWesty, Vanagain, and Boxeer offer a full range of parts, upgrades, and custom mechanical and systems conversion kits to keep these vans on the road as OE manufacturers discontinue production on these parts. For those who have an itch to try out the #VanLife for a shorter period and without the financial commitment, companies like Roamerica, TontoTrails, and adventureRIGS offer nightly and weekly rental opportunities on fully-outfitted campervans ready to hit the road.
For my Honors Project I wrote a complete analysis on the history, development, and modernization of the #VanLife movement. With plans to take to the road for an extended period of time after graduation, I also developed a complete financial plan for a one-year #VanLife experience. The financial plan includes a comprehensive set of budgets that scrutinize the start-up an operational costs of the #VanLife and associated travel.
As the #VanLife craze continues to grow, new businesses are finding ways to meet the demand in the market. For #Vanlifers who own and operate their own camper vans, specialized companies like GoWesty, Vanagain, and Boxeer offer a full range of parts, upgrades, and custom mechanical and systems conversion kits to keep these vans on the road as OE manufacturers discontinue production on these parts. For those who have an itch to try out the #VanLife for a shorter period and without the financial commitment, companies like Roamerica, TontoTrails, and adventureRIGS offer nightly and weekly rental opportunities on fully-outfitted campervans ready to hit the road.
For my Honors Project I wrote a complete analysis on the history, development, and modernization of the #VanLife movement. With plans to take to the road for an extended period of time after graduation, I also developed a complete financial plan for a one-year #VanLife experience. The financial plan includes a comprehensive set of budgets that scrutinize the start-up an operational costs of the #VanLife and associated travel.
ContributorsRischitelli, Noah Gary (Author) / Garverick, Michael (Thesis director) / Dawson, Gregory (Committee member) / WPC Graduate Programs (Contributor) / School of Accountancy (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This thesis project was conducted to create a practical tool to help micro and small local food enterprises identify potential strategies and sources of finance. Currently, many of these enterprises are unable to obtain the financial capital needed to start-up or maintain operations.
Sources and strategies of finance studied and ultimately included in the tool were Loans, Equity, Membership, Crowdfunding, and Grants. The tool designed was a matrix that takes into account various criteria of the business (e.g. business lifecycle, organizational structure, business performance) and generates a financial plan based on these criteria and how they align with the selected business strategies. After strategies are found, stakeholders can search through an institutional database created in conjunction with the matrix tool to find possible institutional providers of financing that relate to the strategy or strategies found.
The tool has shown promise in identifying sources of finance for micro and small local food enterprises in practical use with hypothetical business cases, however further practical use is necessary to provide further input and revise the tool as needed. Ultimately, the tool will likely become fully user-friendly and stakeholders will not need the assistance of another expert helping them to use it. Finally, despite the promise of the tool itself, the fundamental and underlying problem that many of these businesses face (lack of infrastructure and knowledge) still exists, and while this tool can also help capacity-building efforts towards both those seeking and those providing finance, an institutional attitude adjustment towards social and alternative enterprises is necessary in order to further simplify the process of obtaining finance.
Sources and strategies of finance studied and ultimately included in the tool were Loans, Equity, Membership, Crowdfunding, and Grants. The tool designed was a matrix that takes into account various criteria of the business (e.g. business lifecycle, organizational structure, business performance) and generates a financial plan based on these criteria and how they align with the selected business strategies. After strategies are found, stakeholders can search through an institutional database created in conjunction with the matrix tool to find possible institutional providers of financing that relate to the strategy or strategies found.
The tool has shown promise in identifying sources of finance for micro and small local food enterprises in practical use with hypothetical business cases, however further practical use is necessary to provide further input and revise the tool as needed. Ultimately, the tool will likely become fully user-friendly and stakeholders will not need the assistance of another expert helping them to use it. Finally, despite the promise of the tool itself, the fundamental and underlying problem that many of these businesses face (lack of infrastructure and knowledge) still exists, and while this tool can also help capacity-building efforts towards both those seeking and those providing finance, an institutional attitude adjustment towards social and alternative enterprises is necessary in order to further simplify the process of obtaining finance.
ContributorsDwyer, Robert Francis (Author) / Wiek, Arnim (Thesis director) / Forrest, Nigel (Committee member) / Department of Finance (Contributor) / Department of Information Systems (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
This paper will focus on the changes in China's OFDI while also explaining its growth. However, another primary focus will be comparing the relationships between China, Hong Kong, and Africa. This paper will show the correlating changes between the three regions and explain the distribution of China's investments. One argument is that Hong Kong may play a large role in facilitating Chinese investment into Africa, which if not disaggregated, could lead to inaccurate numbers of China's FDI into Africa. The purpose of this paper is to investigate the importance of China's relationship with Hong Kong and Africa. In 2012, Garth Shelton argued that Hong Kong was an important gateway in South Africa's trade with China. Since then, many others have made similar claims in support of Hong Kong's bigger role. However, due to the difficulty of finding specific data for each region, these analyses are incomplete and fail to clearly substantiate their theory. I will try to find a correlation by gathering my own data, tables, and through different interviews.
ContributorsSon, James (Author) / Simonson, Mark (Thesis director) / Iheduru, Okechukwu (Committee member) / Economics Program in CLAS (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This thesis examines the impact of price changes of select microprocessors on the market share and 5-year gross profit net present values of Company X in the networking market through a multi-step analysis. The networking market includes segments including media processing, cloud services, security, routers & switches, and access points. For this thesis our team focused on the routers & switches, as well as the security segments. Company X wants to capitalize on the expected growth of the networking market as it transitions to its fifth generation (henceforth referred to as 5G) by positioning itself favorably in its customers eyes through high quality products offered at competitive prices. Our team performed a quantitative analysis of benchmark data to measure the performances of Company X's products against those of its competitors. We collected this data from third party computer reviewers, as well as the published reports of Company X and its competitors. Through the use of a preference matrix, we then normalized this performance data to adjust for different scales. In order to provide a well-rounded analysis, we adjusted these normalized performances for power consumption (using thermal design power as a proxy) as well as price. We believe these adjusted performances are more valuable than raw benchmark data, as they appeal to the demands of price-sensitive customers. Based on these comparisons, our team was able to assess price changes for their market and discounted financial impact on Company X. Our findings challenge the current pricing of one of the two products being analyzed and suggests a 9% decrease in the price of said product. This recommendation most effectively positions Company X for the development of 5G by offering the best balance of market share and NPV.
ContributorsArias, Stephen (Co-author) / Masson, Taylor (Co-author) / McCall, Kyle (Co-author) / Dimitroff, Alex (Co-author) / Hardy, Sebastian (Co-author) / Simonson, Mark (Thesis director) / Haller, Marcie (Committee member) / School of Accountancy (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05