Matching Items (7)

Methodology for the Environmental Life-Cycle Assessment of Los Angeles Metro’s Orange Bus Rapid Transit and Gold Light Rail Transit Lines

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The goal of this working paper is to provide the methodological background for several upcoming reports and peer-reviewed journal publications. This manuscript only provides background methodology and does not show

The goal of this working paper is to provide the methodological background for several upcoming reports and peer-reviewed journal publications. This manuscript only provides background methodology and does not show or interpret any of the results that are being generated by the research team. The methodology is consistent with the transportation LCA approach developed by the author in previous research. The discussion in this working paper provides the detailed background data and steps used by the research team for their assessment of Los Angeles Metro transit lines and a competing automobile trip.

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  • 2012-07-30

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The Methodology of Economics: How Economists Choose Between Theories

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I began this thesis because I was confused about economics. I wondered why there were so many different models. I didn't understand how they fit together. I was also confused

I began this thesis because I was confused about economics. I wondered why there were so many different models. I didn't understand how they fit together. I was also confused by the assumptions being made. For instance, the assumption that humans are rational utility-maximizers did not seem to agree with my own experiences. With my director Dr. Edward Schlee's help, my thesis has become an inquiry into the state of economic methodology, both in theory and in practice. The questions that drive this paper are: How do economists choose between theories? What is the purpose of economic theory? What is the role of empirical data in assessing models? What role do assumptions play in theory evaluation, and should assumptions make sense? Part I: Methodology is the theoretical portion of the paper. I summarize the essential arguments of the two main schools of thought in economic methodology, and argue for an updated methodology. In Part II: A case study: The expected utility hypothesis, I examine methodology in practice by assessing a handful of studies that seek to test the expected utility hypothesis. Interestingly, I find that there is a different between what economists say they are doing, and what they actually seem to be doing. Throughout this paper, I restrict my analysis to microeconomic theory, simply because this is the area with which I am more familiar. I intend this paper to be a guide for my fellow students and rising economists, as well as for already practicing economists. I hope it helps the reader better understand methodology and improve her own practice.

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Created

Date Created
  • 2013-05

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Intuitions in metaphysics: methodological critique

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This thesis is concerned with the methodological role of intuitions in metaphysics. It is divided into two main parts. Part I argues that an academic field can only employ a

This thesis is concerned with the methodological role of intuitions in metaphysics. It is divided into two main parts. Part I argues that an academic field can only employ a method of gathering evidence if it has established some agreed-upon standards regarding how to evaluate uses of this method. Existing meta-philosophical disputes take the nature of intuitions to be their starting point. This is a mistake. My concern is not the epistemic status of intuitions, but rather how metaphysicians appeal to intuitions as a form of evidence. In order for intuitions to play a viable role in research they must be subject to certain constraints, regardless of whether they allow individual researchers to know that their theories are true. Metaphysicians are not permitted to use intuitions as arbitrarily having different evidential status in different circumstances, nor should they continue to use intuitions as evidence in certain disputes when there is disagreement amongst disputants about whether intuitions should have this evidential status.

Part II is dedicated to showing that metaphysicians currently use intuitions in precisely the sort of inconsistent manner that was shown to be impermissible in Part I. I first consider several competing theories of how intuitions function as evidence and argue that they all fail. As they are currently used in metaphysics, intuitions are analogous to instruments in the sciences in that they are taken to be a substantial non-inferential source of evidence for theories. I then analyze several major metaphysical disputes and show that the source of controversy in these disputes boils down to inconsistencies in how the different parties treat intuitions as evidence. I conclude that metaphysicians must abandon appeals to intuition as evidence--at least until the field can agree upon some general standards that can resolve these inconsistencies.

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Created

Date Created
  • 2014

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Thinking "outside the box: multiple methodologies for the study of home pregnancy test user experience

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Increasing numbers of biomedical products have become eligible for over-the-counter sale in contemporary American consumer culture. What was once the realm of the clinical has moved into the realm of

Increasing numbers of biomedical products have become eligible for over-the-counter sale in contemporary American consumer culture. What was once the realm of the clinical has moved into the realm of the domestic, with the consumer as the interpreter of health issues and communication. This dissertation examines the user experience with the marketing and design of packaging of home pregnancy tests. Studies indicate that more than one-third of women of reproductive age in the U.S. have used a home pregnancy test, yet the test is marketed to a specific demographic of user: one who is white, affluent, and married. How are users’ experiences affected, and how do different methodological frameworks yield results for the study of these user experiences?

In this project, I conduct a series of methodological case studies to show how each reveal various aspects of the user experience of home pregnancy testing. I begin with a case study of three brands of home pregnancy tests, using visual-material rhetorical analysis to uncover the cultural values implicit in packaging. I then move to two case studies involving the results of a National Institutes of Health survey of pregnancy test users. I employ a thematic analysis framework to analyze demographic information about users and to contextualize their narratives. I also conduct corpus linguistics and semantic network analysis with the same data set to model patterns in language. From these varying approaches, each with different underlying assumptions, nuanced aspects of the user experience with the product and its communication emerge. For example, the user’s life circumstances change from initial to subsequent pregnancy test purchase and use so as to suggest more desire for a positive result with subsequent testing, yet many users across these categories express some degree of discomfort when purchasing this product.

I conclude with suggestions based on this research for more ethically informed pregnancy test marketing, and outline avenues for future research for evaluation of home pregnancy test user experience. I finally discuss the implications of multiple methodological approaches for transdisciplinary humanities project design, implementation, and evaluation, with emphasis on the digital and medical humanities.

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Created

Date Created
  • 2015

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Formation, measurement, and imputation of social ties

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Network analysis is a key conceptual orientation and analytical tool in the social sciences that emphasizes the embeddedness of individual behavior within a larger web of social relations. The network

Network analysis is a key conceptual orientation and analytical tool in the social sciences that emphasizes the embeddedness of individual behavior within a larger web of social relations. The network approach is used to better understand the cause and consequence of social interactions which cannot be treated as independent. The relational nature of network data and models, however, amplify the methodological concerns associated with inaccurate or missing data. This dissertation addresses such concerns via three projects. As a motivating substantive example, Project 1 examines factors associated with the selection of interaction partners by students at a large urban high school implementing a reform which, like many organizational improvement initiatives, is associated with a theory of change that posits changes to the structuring of social interactions as a central causal pathway to improved outcomes. A distinctive aspect of the data used in Project 1 is that it was a complete egocentric network census – in addition to being asked about their own relationships, students were asked about the relationships between alters that they nominated in the self-report. This enables two unique examinations of methodological challenges in network survey data collection: Project 2 examines the factors related to how well survey respondents assess the strength of social connections between others, finding that "informant" competence corresponds positively with their social proximity to target dyad as well as their centrality in the network. Project 3 explores using such third-party reports to augment network imputation methods, and finds that incorporating third-party reports into model-based methods provides a significant boost in imputation accuracy. Together these findings provide important implications for collecting and extrapolating data in research contexts where a complete social network census is highly desirable but infeasible.

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Created

Date Created
  • 2019

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Marginalized Significance: Race and Scientific Evidence in the United States Supreme Court

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Law and science are fundamental to the operation of racism in the United States. Law provides structure to maintain and enforce social hierarchies, while science ensures that these hierarchies

Law and science are fundamental to the operation of racism in the United States. Law provides structure to maintain and enforce social hierarchies, while science ensures that these hierarchies are given the guise of truth. Biologists and geneticists have used race in physical sciences to justify social differences, while criminologists, sociologists, and other social scientists use race, and Blackness in particular, as an explain-all for criminality, poverty, or other conditions affecting racialized peoples. Social and physical sciences profoundly impact conceptualizations and constructions of race in society, while juridical bodies give racial science the force of law—placing legal benefits and criminal punishments into play. Yet, no formal rules govern the use of empirical data in opinions of the Supreme Court. My dissertation therefore studies the Court’s use of social scientific evidence in two key cases involving race and discrimination to identify what, if any, social scientific standards the Court has developed for its own analysis of scientific evidence. In so doing, I draw on Critical Race Theory (CRT) and Institutional Ethnography (IE) to develop a methodological framework for the study and use of social sciences in the law. Critical Race scholars generally argue that race is a social and legal construct and racism is endemic, and permanent, while Institutional Ethnography provides a social scientific method for rigorous study of the law by mapping and illuminating relationships of power manifested in social institutions that construct consciousness and place for marginalized groups in society. Combining methods of IE with epistemologies of CRT, I propose Critical Race Methodologies in the study of Fisher v. University of Texas at Austin and Texas Department of Housing and Community Affairs v. The Inclusive Communities Project, Inc. These two cases from recent terms of the Supreme Court involve heavy use of social sciences in briefing and at oral argument, and both cases set standards for racial inclusiveness in Texas. Throughout this dissertation, I look at how law and social sciences co-construct racial meanings and racial power, and how law and social science understand and misunderstand one another in attempting to scientifically understand the role of race in the United States.

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Created

Date Created
  • 2017

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Methodical design approaches to multiple node collection robustness for flip-flop soft error mitigation

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The space environment comprises cosmic ray particles, heavy ions and high energy electrons and protons. Microelectronic circuits used in space applications such as satellites and space stations are prone to

The space environment comprises cosmic ray particles, heavy ions and high energy electrons and protons. Microelectronic circuits used in space applications such as satellites and space stations are prone to upsets induced by these particles. With transistor dimensions shrinking due to continued scaling, terrestrial integrated circuits are also increasingly susceptible to radiation upsets. Hence radiation hardening is a requirement for microelectronic circuits used in both space and terrestrial applications.

This work begins by exploring the different radiation hardened flip-flops that have been proposed in the literature and classifies them based on the different hardening techniques.

A reduced power delay element for the temporal hardening of sequential digital circuits is presented. The delay element single event transient tolerance is demonstrated by simulations using it in a radiation hardened by design master slave flip-flop (FF). Using the proposed delay element saves up to 25% total FF power at 50% activity factor. The delay element is used in the implementation of an 8-bit, 8051 designed in the TSMC 130 nm bulk CMOS.

A single impinging ionizing radiation particle is increasingly likely to upset multiple circuit nodes and produce logic transients that contribute to the soft error rate in most modern scaled process technologies. The design of flip-flops is made more difficult with increasing multi-node charge collection, which requires that charge storage and other sensitive nodes be separated so that one impinging radiation particle does not affect redundant nodes simultaneously. We describe a correct-by-construction design methodology to determine a-priori which hardened FF nodes must be separated, as well as a general interleaving scheme to achieve this separation. We apply the methodology to radiation hardened flip-flops and demonstrate optimal circuit physical organization for protection against multi-node charge collection.

Finally, the methodology is utilized to provide critical node separation for a new hardened flip-flop design that reduces the power and area by 31% and 35% respectively compared to a temporal FF with similar hardness. The hardness is verified and compared to other published designs via the proposed systematic simulation approach that comprehends multiple node charge collection and tests resiliency to upsets at all internal and input nodes. Comparison of the hardness, as measured by estimated upset cross-section, is made to other published designs. Additionally, the importance of specific circuit design aspects to achieving hardness is shown.

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Created

Date Created
  • 2015