Matching Items (3)
Filtering by
- All Subjects: Methodology
- Creators: Clark, Lawrence
- Creators: Daer, Alice R
Description
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.
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.
ContributorsShambhulingaiah, Sandeep (Author) / Clark, Lawrence (Thesis advisor) / Holbert, Keith E. (Committee member) / Seo, Jae sun (Committee member) / Allee, David (Committee member) / Arizona State University (Publisher)
Created2015
Description
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.
ContributorsKang, Dominique (Author) / Schlee, Edward (Thesis director) / Schoellman, Todd (Committee member) / Boerner, Rochus (Committee member) / Barrett, The Honors College (Contributor)
Created2013-05
Description
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.
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.
ContributorsOpel, Dawn S (Author) / Goggin, Maureen Daly (Thesis advisor) / Daer, Alice R (Committee member) / Wernimont, Jacqueline (Committee member) / Arizona State University (Publisher)
Created2015