Matching Items (43,913)
Description
It is common in the analysis of data to provide a goodness-of-fit test to assess the performance of a model. In the analysis of contingency tables, goodness-of-fit statistics are frequently employed when modeling social science, educational or psychological data where the interest is often directed at investigating the association among multi-categorical variables. Pearson's chi-squared statistic is well-known in goodness-of-fit testing, but it is sometimes considered to produce an omnibus test as it gives little guidance to the source of poor fit once the null hypothesis is rejected. However, its components can provide powerful directional tests. In this dissertation, orthogonal components are used to develop goodness-of-fit tests for models fit to the counts obtained from the cross-classification of multi-category dependent variables. Ordinal categories are assumed. Orthogonal components defined on marginals are obtained when analyzing multi-dimensional contingency tables through the use of the QR decomposition. A subset of these orthogonal components can be used to construct limited-information tests that allow one to identify the source of lack-of-fit and provide an increase in power compared to Pearson's test. These tests can address the adverse effects presented when data are sparse. The tests rely on the set of first- and second-order marginals jointly, the set of second-order marginals only, and the random forest method, a popular algorithm for modeling large complex data sets. The performance of these tests is compared to the likelihood ratio test as well as to tests based on orthogonal polynomial components. The derived goodness-of-fit tests are evaluated with studies for detecting two- and three-way associations that are not accounted for by a categorical variable factor model with a single latent variable. In addition the tests are used to investigate the case when the model misspecification involves parameter constraints for large and sparse contingency tables. The methodology proposed here is applied to data from the 38th round of the State Survey conducted by the Institute for Public Policy and Michigan State University Social Research (2005) . The results illustrate the use of the proposed techniques in the context of a sparse data set.
ContributorsMilovanovic, Jelena (Author) / Young, Dennis (Thesis advisor) / Reiser, Mark R. (Thesis advisor) / Wilson, Jeffrey (Committee member) / Eubank, Randall (Committee member) / Yang, Yan (Committee member) / Arizona State University (Publisher)
Created2011
Description
In nineteenth-century France, in rural areas, women washed laundry in the nearest streams or in the sea and hung the linens where they could, on lavender bushes, rocks and grass fields, where it had a quaint, if not artistic quality. In villages, laundresses washed linens in fountains, or other water sources, which were often found at or near the center of town. In either case, laundresses operated in public spaces without problem. I argue that, in Paris, changing ideas about the functioning of city space, the management of public hygiene and decisions about the use of public space, made laundresses and laundry operations matter out of place in the city. This study will demonstrate the changes laundering and laundresses underwent during the nineteenth century in Paris, making them out of place. City administrators and public health officials changed the occupation and places where laundry could be done as they sought to render laundry and laundresses invisible within Paris. In the early nineteenth century the Préfet de la Seine forbade women from using the river banks. In the mid-nineteenth century complaints about the disgraceful aspect of women laundering on the river prompted the Préfet to try to eliminate bateaux-lavoirs. In the late nineteenth century the discovery of microbes focused attention on laundry and laundresses and their potential to transmit diseases prompting another wave of hygiene regulations and questions about closing bateaux-lavoirs and lavoirs. The Préfet and Conseil d'Hygiène's struggle to make them invisible by moving them into approved facilities continued until the end of the nineteenth century. Studying laundresses and laundry sheds light on how the shifts in politics, changes in acceptable uses of public space and public hygiene affected working women. It illustrates the manner in which public hygiene- the Conseil de Salubrité and later the Conseil d'Hygiène, functioned and to what degree they could demand changes to the city in the name of hygiene. Through identifying subtle policy shifts, historians may learn how laundry demonstrates policies on the use of urban space, public hygiene or issues about work.
ContributorsGrüring, Jaimee Kristin (Author) / Fuchs, Rachel G (Thesis advisor) / Thompson, Victoria E (Committee member) / Wright, Johnson K (Committee member) / Arizona State University (Publisher)
Created2011
Description
Buildings in the United States, account for over 68 percent of electricity consumed, 39 percent of total energy use, and 38 percent of the carbon dioxide emissions. By the year 2035, about 75% of the U.S. building sector will be either new or renovated. The energy efficiency requirements of current building codes would have a significant impact on future energy use, hence, one of the most widely accepted solutions to slowing the growth rate of GHG emissions and then reversing it involves a stringent adoption of building energy codes. A large number of building energy codes exist and a large number of studies which state the energy savings possible through code compliance. However, most codes are difficult to comprehend and require an extensive understanding of the code, the compliance paths, all mandatory and prescriptive requirements as well as the strategy to convert the same to energy model inputs. This paper provides a simplified solution for the entire process by providing an easy to use interface for code compliance and energy simulation through a spreadsheet based tool, the ECCO or the Energy Code COmpliance Tool. This tool provides a platform for a more detailed analysis of building codes as applicable to each and every individual building in each climate zone. It also facilitates quick building energy simulation to determine energy savings achieved through code compliance. This process is highly beneficial not only for code compliance, but also for identifying parameters which can be improved for energy efficiency. Code compliance is simplified through a series of parametric runs which generates the minimally compliant baseline building and 30% beyond code building. This tool is seen as an effective solution for architects and engineers for an initial level analysis as well as for jurisdictions as a front-end diagnostic check for code compliance.
ContributorsGoel, Supriya (Author) / Bryan, Harvey J. (Thesis advisor) / Reddy, T. Agami (Committee member) / Addison, Marlin (Committee member) / Arizona State University (Publisher)
Created2011
Description
The purpose of this study is to explore the local life stories of five youths in Belize City, Belize as they experience satellite mediated programming from Black Entertainment Television (BET). It illuminates the manner in which social imagination plays a role in the liberatory practices of the Kriol youth in Belize City, Belize by documenting their life histories in relation to their interactions with BET. The study addresses the following: a) the ways that Kriol youth in Belize make sense of international cable programming; b) the degrees to which these negotiations result in liberatory moments. The study investigates the stories the youth in an through narrative inquiry research methods that can expose how, and to what degree local experiences in the Caribbean can help individuals employ their social imagination for personal growth. Readers of this text may become empowered to adopt the identities of others as their own, and may as a result witness the world from a fresh perspective, perhaps even experiencing moments in which their own life stories are altered. The contextualized categories involving popular BET programming emerged based on how power was distributed and organized in the every day lives of the informants. Empirical examples of hegemonic levels of interaction arose from within the stories. An analysis based on the works of Caribbean scholar Rex Nettleford (1978) was used to study relationships between these levels. There emerged from within the narratives four kinds of hegemonic power negotiations based on degrees of social: Dependence, Impulsive Resistance, Conscious Subordination, Leverage, and Creolization.
ContributorsRichards, Calvin Centae (Author) / Barone, Thomas (Thesis advisor) / Fischman, Gustavo (Committee member) / Hinds, David (Committee member) / Sandlin, Jennifer (Committee member) / Arizona State University (Publisher)
Created2011
Description
Although there are many forms of organization on the Web, one of the most prominent ways to organize web content and websites are tags. Tags are keywords or terms that are assigned to a specific piece of content in order to help users understand the common relationships between pieces of content. Tags can either be assigned by an algorithm, the author, or the community. These tags can also be organized into tag clouds, which are visual representations of the structure and organization contained implicitly within these tags. Importantly, little is known on how we use these different tagging structures to understand the content and structure of a given site. This project examines 2 different characteristics of tagging structures: font size and spatial orientation. In order to examine how these different characteristics might interact with individual differences in attentional control, a measure of working memory capacity (WMC) was included. The results showed that spatial relationships affect how well users understand the structure of a website. WMC was not shown to have any significant effect; neither was varying the font size. These results should better inform how tags and tag clouds are used on the Web, and also provide an estimation of what properties to include when designing and implementing a tag cloud on a website.
ContributorsBanas, Steven (Author) / Sanchez, Christopher A (Thesis advisor) / Branaghan, Russell (Committee member) / Cooke, Nancy J. (Committee member) / Arizona State University (Publisher)
Created2011
Description
The occurrence of exogenic, meteoritic materials on the surface of any world presents opportunities to explore a variety of significant problems in the planetary sciences. In the case of Mars, meteorites found on its surface may help to 1) constrain atmospheric conditions during their time of arrival; 2) provide insights into possible variabilities in meteoroid type sampling between Mars and Earth space environments; 3) aid in our understanding of soil, dust, and sedimentary rock chemistry; 4) assist with the calibration of crater-age dating techniques; and 5) provide witness samples for chemical and mechanical weathering processes. The presence of reduced metallic iron in approximately 88 percent of meteorite falls renders the majority of meteorites particularly sensitive to oxidation by H2O interaction. This makes them excellent markers for H2O occurrence. Several large meteorites have been discovered at Gusev Crater and Meridiani Planum by the Mars Exploration Rovers (MERs). Significant morphologic characteristics interpretable as weathering features in the Meridiani suite of iron meteorites include a 1) large pit lined with delicate iron protrusions suggestive of inclusion removal by corrosive interaction; 2) differentially eroded kamacite and taenite lamellae on three of the meteorites, providing relative timing through cross-cutting relationships with deposition of 3) an iron oxide-rich dark coating; and 4) regmaglypted surfaces testifying to regions of minimal surface modification; with other regions in the same meteorites exhibiting 5) large-scale, cavernous weathering. Iron meteorites found by Mini-TES at both Meridiani Planum and Gusev Crater have prompted laboratory experiments designed to explore elements of reflectivity, dust cover, and potential oxide coatings on their surfaces in the thermal infrared using analog samples. Results show that dust thickness on an iron substrate need be only one tenth as great as that on a silicate rock to obscure its infrared signal. In addition, a database of thermal emission spectra for 46 meteorites was prepared to aid in the on-going detection and interpretation of these valuable rocks on Mars using Mini-TES instruments on both MER spacecraft. Applications to the asteroidal sciences are also relevant and intended for this database.
ContributorsAshley, James Warren (Author) / Christensen, Philip R. (Thesis advisor) / Sharp, Thomas G (Committee member) / Shock, Everett L (Committee member) / Hervig, Richard L (Committee member) / Zolotov, Mikhail Y (Committee member) / Arizona State University (Publisher)
Created2011
Description
A method of determining nanoparticle temperature through fluorescence intensity levels is described. Intracellular processes are often tracked through the use of fluorescence tagging, and ideal temperatures for many of these processes are unknown. Through the use of fluorescence-based thermometry, cellular processes such as intracellular enzyme movement can be studied and their respective temperatures established simultaneously. Polystyrene and silica nanoparticles are synthesized with a variety of temperature-sensitive dyes such as BODIPY, rose Bengal, Rhodamine dyes 6G, 700, and 800, and Nile Blue A and Nile Red. Photographs are taken with a QImaging QM1 Questar EXi Retiga camera while particles are heated from 25 to 70 C and excited at 532 nm with a Coherent DPSS-532 laser. Photographs are converted to intensity images in MATLAB and analyzed for fluorescence intensity, and plots are generated in MATLAB to describe each dye's intensity vs temperature. Regression curves are created to describe change in fluorescence intensity over temperature. Dyes are compared as nanoparticle core material is varied. Large particles are also created to match the camera's optical resolution capabilities, and it is established that intensity values increase proportionally with nanoparticle size. Nile Red yielded the closest-fit model, with R2 values greater than 0.99 for a second-order polynomial fit. By contrast, Rhodamine 6G only yielded an R2 value of 0.88 for a third-order polynomial fit, making it the least reliable dye for temperature measurements using the polynomial model. Of particular interest in this work is Nile Blue A, whose fluorescence-temperature curve yielded a much different shape from the other dyes. It is recommended that future work describe a broader range of dyes and nanoparticle sizes, and use multiple excitation wavelengths to better quantify each dye's quantum efficiency. Further research into the effects of nanoparticle size on fluorescence intensity levels should be considered as the particles used here greatly exceed 2 ìm. In addition, Nile Blue A should be further investigated as to why its fluorescence-temperature curve did not take on a characteristic shape for a temperature-sensitive dye in these experiments.
ContributorsTomforde, Christine (Author) / Phelan, Patrick (Thesis advisor) / Dai, Lenore (Committee member) / Adrian, Ronald (Committee member) / Arizona State University (Publisher)
Created2011
Description
Climate change is not a thing of the future. Indigenous people are being affected by climate changes now. Native American Earth scientists could help Native communities deal with both climate change and environmental pollution issues, but are noticeably lacking in Earth Science degree programs. The Earth Sciences produce the lowest percentage of minority scientists when compared with other science and engineering fields. Twenty semi-structured interviews were gathered from American Indian/ Alaska Native Earth Scientists and program directors who work directly with Native students to broaden participation in the field. Data was analyzed using qualitative methods and constant comparison analysis. Barriers Native students faced in this field are discussed, as well as supports which go the furthest in assisting achievement of higher education goals. Program directors give insight into building pathways and programs to encourage Native student participation and success in Earth Science degree programs. Factors which impede obtaining a college degree include financial barriers, pressures from familial obligations, and health issues. Factors which impede the decision to study Earth Science include unfamiliarity with geoscience as a field of study and career choice, the uninviting nature of Earth Science as a profession, and curriculum that is irrelevant to the practical needs of Native communities or courses which are inaccessible geographically. Factors which impede progress that are embedded in Earth Science programs include educational preparation, academic information and counseling and the prevalence of a Western scientific perspective to the exclusion of all other perspectives. Intradepartmental relationships also pose barriers to the success of some students, particularly those who are non-traditional students (53%) or women (80%). Factors which support degree completion include financial assistance, mentors and mentoring, and research experiences. Earth scientists can begin broaden participation by engaging in community-inspired research, which stems from the needs of a community and is developed in collaboration with it. Designed to be useful in meeting the needs of the community, it should include using members of the community to help gather and analyze data. These community members could be students or potential students who might be persuaded to pursue an Earth Science degree.
ContributorsBueno Watts, Nievita F (Author) / Baker, Dale R. (Thesis advisor) / Mckinley Jones Brayboy, Bryan (Committee member) / Margolis, Eric (Committee member) / Arizona State University (Publisher)
Created2011
Description
This dissertation describes the work on two projects which involves measuring molecular conductance and studying their properties on the nanoscale using various Scanning Tunneling Microscopy (STM) techniques. The first molecule studied was a porphyrin-fullerene moiety known as a molecular Dyad for photovoltaic applications. This project is further divided into two section, the first one involving the characterization of the Dyad monolayers and conductance measurement in the dark. The Dyads are designed to form charge separated states on illumination. The lifetime of the charged states have been measured efficiently but the single-molecule conductance through the molecules have yet to be characterized. The second part of the project describes the set-up of a novel sample stage which enables the study of molecular conductance under illumination. This part also describes the subsequent study of the molecule under illumination and the observation of a unique charge-separated state. It also contains the verification of the presence of this charge-separated using other characterization techniques like transient absorption spectroscopy. The second project described in the dissertation was studying and comparing the predicted rectifying nature of two molecules, identical in every way except for one stereocenter. This project describes the formation of monolayers of the molecule on gold and then studying and analyzing the current-voltage characteristics of the molecules and looking for rectification. Both the molecules proved to be rectifying, one more than the other as predicted by theoretical calculations.
ContributorsBhattacharyya, Shreya (Author) / Lindsay, Stuart (Thesis advisor) / Moore, Ana (Committee member) / Levitus, Marcia (Committee member) / Arizona State University (Publisher)
Created2011
Description
In the past decade, research on the motor control side of neuroprosthetics has steadily gained momentum. However, modern research in prosthetic development supplements a focus on motor control with a concentration on sensory feedback. Simulating sensation is a central issue because without sensory capabilities, the sophistication of the most advanced motor control system fails to reach its full potential. This research is an effort toward the development of sensory feedback specifically for neuroprosthetic hands. The present aim of this work is to understand the processing and representation of cutaneous sensation by evaluating performance and neural activity in somatosensory cortex (SI) during a grasp task. A non-human primate (Macaca mulatta) was trained to reach out and grasp textured instrumented objects with a precision grip. Two different textures for the objects were used, 100% cotton cloth and 60-grade sandpaper, and the target object was presented at two different orientations. Of the 167 cells that were isolated for this experiment, only 42 were recorded while the subject executed a few blocks of successful trials for both textures. These latter cells were used in this study's statistical analysis. Of these, 37 units (88%) exhibited statistically significant task related activity. Twenty-two units (52%) exhibited statistically significant tuning to texture, and 16 units (38%) exhibited statistically significant tuning to posture. Ten of the cells (24%) exhibited statistically significant tuning to both texture and posture. These data suggest that single units in somatosensory cortex can encode multiple phenomena such as texture and posture. However, if this information is to be used to provide sensory feedback for a prosthesis, scientists must learn to further parse cortical activity to discover how to induce specific modalities of sensation. Future experiments should therefore be developed that probe more variables and that more systematically and comprehensively scan somatosensory cortex. This will allow researchers to seek out the existence or non-existence of cortical pockets reserved for certain modalities of sensation, which will be valuable in learning how to later provide appropriate sensory feedback for a prosthesis through cortical stimulation.
ContributorsNaufel, Stephanie (Author) / Helms Tillery, Stephen I (Thesis advisor) / Santos, Veronica J (Thesis advisor) / Buneo, Christopher A (Committee member) / Robert, Jason S (Committee member) / Arizona State University (Publisher)
Created2011