Matching Items (4)
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- All Subjects: Methodology
- Creators: Bowers, Nicole
- Creators: Allee, David
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
This dissertation deals with the confluence of neoliberal and dominant Western social pressures in tension with researchers and educators striving toward a more sustainable world in light of the Anthropocene. Although scientists see the Anthropocene as a problem of human activity and environmental degradation, many social scientists and humanities researchers also see it as a problem with entrenched ways of thought. Current ways of thought complicit in the making of the Anthropocene include centering all thought, control, and agency in the radically individual human, centering science as the only legitimate access to knowledge, and presenting that knowledge as apolitical absolute truth. I engage in research creation activated by the minor gestures of human/nature entanglement in the Anthropocene and the promise of place in environmental and sustainability education. As such, I embark on the invention of a new ecology of practices that takes the process philosophy of Alfred North Whitehead as their guiding foundation. As part of this invention circumventing normative neoliberal and Western logics, I take Ajo, Arizona and the surrounding Sonoran Desert as a partner in more-than-human process inquiry. I live in Ajo and explore the Sonoran Desert for four months of data generation employing basic techniques of ethnography divorced from their neopositivist founding theories.
Bodies generated from my entanglement with Ajo and the desert participate in inventing Remixing Data Experiences (RDE), a novel data engagement technique. Through RDE, my more-than-human partners and I create ideas by engaging in arts-based techniques that form multimedia art-workings. The ideas generated include Oasis, Decline, Celebrate, Precarity, and Directions. I respond to each idea through anarchival written texts in a variety of genres including ethnographic memoir, short fiction, essay, ballad, and talk poem. I put these ideas into conversation with current methodological and education literature to illustrate that aesthetic-based inquiry contributes new ways forward in the Anthropocene. These new ways include rhythms of certainty and uncertainty in knowledge creation, participating in reciprocal affective capabilities of bodies in joyful knowing, developing modest abstractions that frequently engage concrete experience, and inclusion of aesthetic experiences in learning and inquiry.
ContributorsBowers, Nicole (Author) / Carlson, David L (Thesis advisor) / Koro, Mirka (Committee member) / Jordan, Michelle (Committee member) / Arizona State University (Publisher)
Created2021
Description
This multimodal study brought an open, constructively critical challenge to the standard means of process in, and knowledge production from, qualitative inquiry. Using as a context, dyslexia, and the assistive technology lifeworlds of postsecondary students, this study co-partnered with six college students with dyslexia. Co-partnership allowed for an emergence of new awareness that the experience of dyslexia and assistive technology is mediated through innumerable dynamics of interactions with and through the world. Methodologically, the study suggested that it is possible to: (a) situate, center, and validate disability throughout all phases of qualitative inquiry; (b) make the discrete parts of action research more inclusive of disability; (c) reduce physical and intellectual access barriers to qualitative inquiry; and (d) regard as reasonable and rigorous research that is produced by bodies and minds that may not process information in typical ways. Emancipatory action research was used to thread together an understanding of the complexities of self, being, and reality for a marginalized group and how systems, structures, interactions, spaces, and language are superimposed on experiences of disability. The emancipatory spirited study allowed space for co-constructed meaning making through dynamic multimodalities of method including audio-visual data co-constructed through narrative storytelling; an analysis through deep listening and video editing – illuminating ‘bright spots’ in the broader lifeworld perspective of dyslexia and assistive technology. The innovative co-constructed products of the dissertation were a 2-hour film, a researcher reflection video, professional development guides for assistive technology and qualitative inquiry, and a methods chapter as part of an edited book prospectus. By engaging with this study, the audience will experience consciousness raising with respect to disability experience and witness a reclaiming of the voice of that experience through inclusive research. This study offers a transformative perspective for future work by inviting critical consideration and co-construction of meaning of an expanded conceptualization of assistive technology as an embodied, negotiated experience; and increases awareness that diverse bodyminds offer powerful narratives of diversity in the human condition and why that matters. .
ContributorsBunch, Jacob Colby (Author) / Graves-Wolf, Leigh (Thesis advisor) / Bowers, Nicole (Thesis advisor) / Harrop, Lance (Committee member) / Nusbaum, Emily A. (Committee member) / Arizona State University (Publisher)
Created2023