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- Creators: Prokofiev, Sergey, 1891-1953
Description
The original mediums were not texts or technologies; they were ritual actors performing acts of mediumship. Mediating between determined norms (the status quo) and emergent trends (change), they invoked divine authority to conjure meanings that proved adaptive, nonadaptive and/or maladaptive. With the advent of the written word, ritual became formalized and codified. The medium became a communication device, something abstract and external to the human condition. It then became possible to speak of "media effects" imposing influence in a logical deterministic manner. Yet with the advent of new media, we are witnessing a return to modes of cultural discourse that are spontaneous, interactive, communal and unscripted, all hallmarks of ritual action. This "ritual return" centers on the emergence of the "prosumer" (producer/consumer), a figure actively engaged in mediating practices. While resembling the original archaic "medium" in some respects, the prosumer is a "literate ritualist" allied with a multiplicity of cultural tribes. Thus the "new media" has given rise to "the new medium." The pages that follow focus on acts of contemporary mediumship, examining related concepts such as "ecology," "niche," "role," "affordance," and "trope." Each section considers how specific mediating practices afford and constrain modes of ritualized behavior. I call this practice-oriented approach to media studies "praxism."
ContributorsGyori, Bradford (Author) / Goggin, Maureen (Thesis advisor) / Baker, Aaron (Committee member) / Hjorleifur Jonsson (Committee member) / Arizona State University (Publisher)
Created2011
Model Based Automatic and Robust Spike Sorting for Large Volumes of Multi-channel Extracellular Data
Description
Spike sorting is a critical step for single-unit-based analysis of neural activities extracellularly and simultaneously recorded using multi-channel electrodes. When dealing with recordings from very large numbers of neurons, existing methods, which are mostly semiautomatic in nature, become inadequate.
This dissertation aims at automating the spike sorting process. A high performance, automatic and computationally efficient spike detection and clustering system, namely, the M-Sorter2 is presented. The M-Sorter2 employs the modified multiscale correlation of wavelet coefficients (MCWC) for neural spike detection. At the center of the proposed M-Sorter2 are two automatic spike clustering methods. They share a common hierarchical agglomerative modeling (HAM) model search procedure to strategically form a sequence of mixture models, and a new model selection criterion called difference of model evidence (DoME) to automatically determine the number of clusters. The M-Sorter2 employs two methods differing by how they perform clustering to infer model parameters: one uses robust variational Bayes (RVB) and the other uses robust Expectation-Maximization (REM) for Student’s 𝑡-mixture modeling. The M-Sorter2 is thus a significantly improved approach to sorting as an automatic procedure.
M-Sorter2 was evaluated and benchmarked with popular algorithms using simulated, artificial and real data with truth that are openly available to researchers. Simulated datasets with known statistical distributions were first used to illustrate how the clustering algorithms, namely REMHAM and RVBHAM, provide robust clustering results under commonly experienced performance degrading conditions, such as random initialization of parameters, high dimensionality of data, low signal-to-noise ratio (SNR), ambiguous clusters, and asymmetry in cluster sizes. For the artificial dataset from single-channel recordings, the proposed sorter outperformed Wave_Clus, Plexon’s Offline Sorter and Klusta in most of the comparison cases. For the real dataset from multi-channel electrodes, tetrodes and polytrodes, the proposed sorter outperformed all comparison algorithms in terms of false positive and false negative rates. The software package presented in this dissertation is available for open access.
This dissertation aims at automating the spike sorting process. A high performance, automatic and computationally efficient spike detection and clustering system, namely, the M-Sorter2 is presented. The M-Sorter2 employs the modified multiscale correlation of wavelet coefficients (MCWC) for neural spike detection. At the center of the proposed M-Sorter2 are two automatic spike clustering methods. They share a common hierarchical agglomerative modeling (HAM) model search procedure to strategically form a sequence of mixture models, and a new model selection criterion called difference of model evidence (DoME) to automatically determine the number of clusters. The M-Sorter2 employs two methods differing by how they perform clustering to infer model parameters: one uses robust variational Bayes (RVB) and the other uses robust Expectation-Maximization (REM) for Student’s 𝑡-mixture modeling. The M-Sorter2 is thus a significantly improved approach to sorting as an automatic procedure.
M-Sorter2 was evaluated and benchmarked with popular algorithms using simulated, artificial and real data with truth that are openly available to researchers. Simulated datasets with known statistical distributions were first used to illustrate how the clustering algorithms, namely REMHAM and RVBHAM, provide robust clustering results under commonly experienced performance degrading conditions, such as random initialization of parameters, high dimensionality of data, low signal-to-noise ratio (SNR), ambiguous clusters, and asymmetry in cluster sizes. For the artificial dataset from single-channel recordings, the proposed sorter outperformed Wave_Clus, Plexon’s Offline Sorter and Klusta in most of the comparison cases. For the real dataset from multi-channel electrodes, tetrodes and polytrodes, the proposed sorter outperformed all comparison algorithms in terms of false positive and false negative rates. The software package presented in this dissertation is available for open access.
ContributorsMa, Weichao (Author) / Si, Jennie (Thesis advisor) / Papandreou-Suppappola, Antonia (Committee member) / He, Jingrui (Committee member) / Helms Tillery, Stephen (Committee member) / Arizona State University (Publisher)
Created2019
Description
This research compares shifts in a SuperSpec titanium nitride (TiN) kinetic inductance detector's (KID's) resonant frequency with accepted models for other KIDs. SuperSpec, which is being developed at the University of Colorado Boulder, is an on-chip spectrometer designed with a multiplexed readout with multiple KIDs that is set up for a broadband transmission of these measurements. It is useful for detecting radiation in the mm and sub mm wavelengths which is significant since absorption and reemission of photons by dust causes radiation from distant objects to reach us in infrared and far-infrared bands. In preparation for testing, our team installed stages designed previously by Paul Abers and his group into our cryostat and designed and installed other parts necessary for the cryostat to be able to test devices on the 250 mK stage. This work included the design and construction of additional parts, a new setup for the wiring in the cryostat, the assembly, testing, and installation of several stainless steel coaxial cables for the measurements through the devices, and other cryogenic and low pressure considerations. The SuperSpec KID was successfully tested on this 250 mK stage thus confirming that the new setup is functional. Our results are in agreement with existing models which suggest that the breaking of cooper pairs in the detector's superconductor which occurs in response to temperature, optical load, and readout power will decrease the resonant frequencies. A negative linear relationship in our results appears, as expected, since the parameters are varied only slightly so that a linear approximation is appropriate. We compared the rate at which the resonant frequency responded to temperature and found it to be close to the expected value.
ContributorsDiaz, Heriberto Chacon (Author) / Mauskopf, Philip (Thesis director) / McCartney, Martha (Committee member) / Department of Physics (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Supernovae are vital to supplying necessary elements to forming bodies in our solar systems. This project studies the creation of a subset of these necessary elements, called short-lived radionuclides (SLRs). SLRs are isotopes with relatively short half-lives and can serve as heat sources for forming planetary bodies, and their traces can be used to date stellar events. Computational models of asymmetric supernovae provide opportunities to study the effect of explosion geometry on the SLR yields. We are most interested in the production of \iso{Al}{26}, \iso{Fe}{60}, and \iso{Ca}{41}, whose decayed products are found in our own solar system. To study the effect of explosion asymmetries in supernovae, we use TYCHO stellar evolution code, SNSHP smooth particle hydrodynamics code for 3D explosion simulations, Burn code for nucleosythesis post-processing, and Python code written to analyze the output of the post-processing code.
ContributorsJohnson, Charlotte (Author) / Young, Patrick (Thesis director) / Lunardini, Cecilia (Committee member) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
We hypothesized that recurrent exposure to a temporal discounting task would habitize participants, so that they become insensitive to framing effects. Temporal discounting is a behavioral trend which describes how people discount the value of a reward dependent on the time until receipt. Participants completed a temporal discounting task weekly for five weeks, to promote formation of a habitual decision strategy. Concomitant with this, we expected that people would shift their decision process from a deliberate, goal-oriented approach that is sensitive to changes in reward outcomes and environmental context, to a simplified, automatic approach that minimizes cognitive effort. We expected that this shift in decision strategy would be evident in a reduced influence of contextual effects on choice outcomes. We tested this hypothesis by leveraging two framing effects \u2014 the date/delay effect and the decimal effect. Consistent with our hypothesis, we find that the date/delay effect is significant on week 1, shows significant changes in week 1 to week 5, and is no longer significant on week 5. The results for the decimal effects were not significant. We discuss these results with respect to the cognitive processes that underlie temporal discounting and self-control.
ContributorsSt Amand, Jesse Dean (Author) / McClure, Samuel (Thesis director) / Sanabria, Federico (Committee member) / School of Molecular Sciences (Contributor) / Department of Physics (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
A problem of interest in theoretical physics is the issue of the evaporation of black holes via Hawking radiation subject to a fixed background. We approach this problem by considering an electromagnetic analogue, where we have substituted Hawking radiation with the Schwinger effect. We treat the case of massless QED in 1+1 dimensions with the path integral approach to quantum field theory, and discuss the resulting Feynman diagrams from our analysis. The results from this thesis may be useful to find a version of the Schwinger effect that can be solved exactly and perturbatively, as this version may provide insights to the gravitational problem of Hawking radiation.
ContributorsDhumuntarao, Aditya (Author) / Parikh, Maulik (Thesis director) / Davies, Paul C. W. (Committee member) / Department of Physics (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Unauthorized confronts the relationship between technology and personhood in the modern world. More specifically, it addresses the personal and social effects of border politics within the frame of cyber crime. The short film takes place in the near future where a hacker can create citizenship for anyone she wants, effectively turning anyone into a legal person in the United States. This parallels the real life struggles of unauthorized immigrants trying to gain a new life this side of the border despite the overwhelming backlash from the conservative and xenophobic population. The main character's ability to grant citizenship forces the viewer to confront what being a person really means. The film also alludes to the popularized antics of modern day hackers and whistleblowers who are often turned into heroes for fighting the establishment despite their character flaws. The protagonist of Unauthorized struggles through underhanded sexism and blatant racism as well as her own personal struggles with drug addiction and failed relationships. These are very real struggles women face in technology jobs and life in general. The main character's actions ultimately destroy every relationship that she's established, including the connection to her own family. This film, in short, is about the walls people build between each other, both physical and social.
ContributorsStabley, Justin E. (Author) / Bradley, Christopher (Thesis director) / Baker, Aaron (Committee member) / Department of English (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Observations of four times ionized iron and nickel (Fe V & Ni V) in the G191-B2B white dwarf spectrum have been used to test for variations in the fine structure constant, α, in the presence of strong gravitational fields. The laboratory wavelengths for these ions were thought to be the cause of inconsistent conclusions regarding the
variation of α as observed through the white dwarf spectrum. This thesis presents 129 revised Fe V wavelengths (1200 Å to 1600 Å) and 161 revised Ni V wavelengths (1200 Å to 1400 Å) with uncertainties of approximately 3 mÅ. A systematic calibration error
is identified in the previous Ni V wavelengths and is corrected in this work. The evaluation of the fine structure variation is significantly improved with the results
found in this thesis.
variation of α as observed through the white dwarf spectrum. This thesis presents 129 revised Fe V wavelengths (1200 Å to 1600 Å) and 161 revised Ni V wavelengths (1200 Å to 1400 Å) with uncertainties of approximately 3 mÅ. A systematic calibration error
is identified in the previous Ni V wavelengths and is corrected in this work. The evaluation of the fine structure variation is significantly improved with the results
found in this thesis.
ContributorsWard, Jacob Wolfgang (Author) / Treacy, Michael (Thesis director) / Alarcon, Ricardo (Committee member) / Nave, Gillian (Committee member) / Department of Physics (Contributor) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The Walt Disney Company has been a worldwide phenomenon for over half a century. Disney's animated films in particular impact a large number of individuals around the world. The fact that they rerelease popular films every few years lends to the lasting influence these movies will hold in the lives of children to come. It is important to examine the messages Disney animated films can teach children in regards to women's roles, United States history, and racial difference. This essay examines these topics as they appear in Disney's Snow White and the Seven Dwarves, The Little Mermaid, Pocahontas, and The Lion King. Lastly, it examines the potential impact these films can leave on children and suggests ways in which adults can help children analyze what they see in the media.
ContributorsMonnig, Elizabeth Ann (Author) / Baker, Aaron (Thesis director) / Sandlin, Jennifer (Committee member) / Barrett, The Honors College (Contributor) / School of Film, Dance and Theatre (Contributor) / Department of English (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2014-12
Description
In this paper, it is determined that learning retention decreases with age and there is a linear rate of decrease. In this study, four male Long-Evans Rats were used. The rats were each trained in 4 different tasks throughout their lifetime, using a food reward as motivation to work. Rats were said to have learned a task at the age when they received the highest accuracy during a task. A regression of learning retention was created for the set of studied rats: Learning Retention = 112.9 \u2014 0.085919 x (Age at End of Task), indicating that learning retention decreases at a linear rate, although rats have different rates of decrease of learning retention. The presence of behavioral training was determined not to have a positive impact on this rate. In behavioral studies, there were statistically significant differences between timid/outgoing and large ball ability between W12 and Z12. Rat W12 had overall better learning retention and also was more compliant, did not resist being picked up and traveled more frequently at high speeds (in the large ball) than Z12. Further potential studies include implanting an electrode into the frontal cortex in order to compare neuro feedback with learning retention, and using human subjects to find the rate of decrease in learning retention. The implication of this study, if also true for human subjects, is that older persons may need enhanced training or additional refresher training in order to retain information that is learned at a later age.
ContributorsSpinrad, Amelia (Author) / Si, Jennie (Thesis director) / Thompson, Patrick (Committee member) / Ma, Weichao (Committee member) / Barrett, The Honors College (Contributor)
Created2014-05