Matching Items (4)
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- All Subjects: Measurement
- Genre: Academic theses
- Creators: Papova, Anna
- Creators: Atkin, Annabelle L.
Description
Dimensional Metrology is the branch of science that determines length, angular, and geometric relationships within manufactured parts and compares them with required tolerances. The measurements can be made using either manual methods or sampled coordinate metrology (Coordinate measuring machines). Manual measurement methods have been in practice for a long time and are well accepted in the industry, but are slow for the present day manufacturing. On the other hand CMMs are relatively fast, but these methods are not well established yet. The major problem that needs to be addressed is the type of feature fitting algorithm used for evaluating tolerances. In a CMM the use of different feature fitting algorithms on a feature gives different values, and there is no standard that describes the type of feature fitting algorithm to be used for a specific tolerance. Our research is focused on identifying the feature fitting algorithm that is best used for each type of tolerance. Each algorithm is identified as the one to best represent the interpretation of geometric control as defined by the ASME Y14.5 standard and on the manual methods used for the measurement of a specific tolerance type. Using these algorithms normative procedures for CMMs are proposed for verifying tolerances. The proposed normative procedures are implemented as software. Then the procedures are verified by comparing the results from software with that of manual measurements.
To aid this research a library of feature fitting algorithms is developed in parallel. The library consists of least squares, Chebyshev and one sided fits applied on the features of line, plane, circle and cylinder. The proposed normative procedures are useful for evaluating tolerances in CMMs. The results evaluated will be in accordance to the standard. The ambiguity in choosing the algorithms is prevented. The software developed can be used in quality control for inspection purposes.
To aid this research a library of feature fitting algorithms is developed in parallel. The library consists of least squares, Chebyshev and one sided fits applied on the features of line, plane, circle and cylinder. The proposed normative procedures are useful for evaluating tolerances in CMMs. The results evaluated will be in accordance to the standard. The ambiguity in choosing the algorithms is prevented. The software developed can be used in quality control for inspection purposes.
ContributorsVemulapalli, Prabath (Author) / Shah, Jami J. (Thesis advisor) / Davidson, Joseph K. (Committee member) / Takahashi, Timothy (Committee member) / Arizona State University (Publisher)
Created2014
Description
Self-control has been shown to predict both health risk and health protective outcomes. Although top-down or “good” self-control is typically examined as a unidimensional construct, research on “poor” self-control suggests that multiple dimensions may be necessary to capture aspects of self-control. The current study sought to create a new brief survey measure of top-down self-control that differentiates between self-control capacity, internal motivation, and external motivation. Items were adapted from the Brief Self-Control Scale (BSCS; Tangney, Baumeister, & Boone, 2004) and were administered through two online surveys to 347 undergraduate students enrolled in introductory psychology courses at Arizona State University. The Self-Control Motivation and Capacity Survey (SCMCS) showed strong evidence of validity and reliability. Exploratory and confirmatory factor analyses supported a 3-factor structure of the scale consistent with the underlying theoretical model. The final 15-item measure demonstrated excellent model fit, chi-square = 89.722 p=.077, CFI = .989, RMSEA = .032, SRMR = .045. Despite several limitations including the cross-sectional nature of most analyses, self-control capacity, internal motivation, and external motivation uniquely related to various self-reported behavioral outcomes, and accounted for additional variance beyond that accounted for by the BSCS. Future studies are needed to establish the stability of multiple dimensions of self-control, and to develop state-like and domain-specific measures of self-control. While more research in this area is needed, the current study demonstrates the importance of studying multiple aspects of top-down self-control, and may ultimately facilitate the tailoring of interventions to the needs of individuals based on unique profiles of self-control capacity and motivation.
ContributorsPapova, Anna (Author) / Corbin, William R. (Thesis advisor) / Karoly, Paul (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2016
Description
Self-control has been shown to be an important influence behind a variety of risk and protective behaviors, such as substance abuse. Although prior research points to the existence of multiple dimensions of self-control, this concept is not consistently defined and frequently only studied as a conglomerate in clinical research. The current study sought to examine how two experimental manipulations of subcomponents of self-control (motivation and self-efficacy) affect real-world consumptive behavior after accounting for executive function. Additionally, the validity and reliability of a brief state survey measure of perceived self-control capacity, internal motivation, and external motivation was tested. The goal was to examine how basic scientific principles involved in self-control translate into clinically relevant behaviors, which may inform understanding of momentary lapses in self-control behavior, potentially leading to novel prevention and intervention efforts. 94 college students completed a 1-2 hour laboratory protocol during which they completed survey and laboratory-based tasks of self-control and related behaviors, executive function, and ad libitum alcohol consumption. Results showed that the self-efficacy manipulation successfully increased perceived self-control capacity, although this did not lead to a significant reduction in consumption. The motivation manipulation neither increased motivation nor reduced consumption in this sample. However, the brief state survey measure of self-control subcomponents demonstrated strong test-retest reliability and distinction from trait self-control, demonstrating its viability for use in future research. By elucidating the relationships between specific mechanisms of self-control, laboratory-based tasks and manipulations, and real-world consumptive behaviors, prevention and intervention efforts for problems such as alcohol abuse may be tailored to the needs of the individual and made more impactful and cost-effective.
ContributorsPapova, Anna (Author) / Corbin, William R. (Thesis advisor) / Brewer, Gene (Committee member) / Karoly, Paul (Committee member) / McClure, Samuel (Committee member) / Arizona State University (Publisher)
Created2020
Description
Pew Research Center reported in 2015 that already one-in-seven infants born in the United States are Multiracial (Livingston, 2017). Therefore, the number of Multiracial families is growing, and there is a need to understand how parents are engaging in racial-ethnic socialization, or the transmission of messages to Multiracial children about race, ethnicity, and culture (Atkin & Yoo, 2019; Hughes et al., 2006). I conducted a qualitative interview study with 20 Multiracial emerging adults to understand the types of racial-ethnic socialization messages Multiracial youth receive from their parents, and used these themes to inform the development and validation of the first measure of racial-ethnic socialization for Multiracial youth, the Multiracial Youth Socialization (MY-Soc) Scale.
Study 1 identified nine themes of racial-ethnic socialization content: cultural socialization, racial identity socialization, preparation for bias socialization, colorblind socialization, race conscious socialization, cultural diversity appreciation socialization, negative socialization, exposure to diversity socialization, and silent socialization. Study 2 utilized a sample of 902 Multiracial emerging adults to develop and validate the MY-Soc scale. Items were written to assess all of the themes identified in Study 1, with the exception of exposure to diversity socialization, and the survey was designed to collect responses regarding the socialization practices of two of the youths’ primary caregivers. The sample was split to run exploratory factor analysis and confirmatory factor analysis, finding support for a 62-item scale measuring all eight themes. The MY-Soc Scale was also supported by validity and reliability tests. The two studies advance the literature by increasing understanding of the racial-ethnic socialization experiences of Multiracial youth of diverse racial backgrounds. The MY-Soc Scale contributes an important tool for scholars and practitioners to learn which racial-ethnic socialization messages are promotive for Multiracial youth development in different contexts.
Study 1 identified nine themes of racial-ethnic socialization content: cultural socialization, racial identity socialization, preparation for bias socialization, colorblind socialization, race conscious socialization, cultural diversity appreciation socialization, negative socialization, exposure to diversity socialization, and silent socialization. Study 2 utilized a sample of 902 Multiracial emerging adults to develop and validate the MY-Soc scale. Items were written to assess all of the themes identified in Study 1, with the exception of exposure to diversity socialization, and the survey was designed to collect responses regarding the socialization practices of two of the youths’ primary caregivers. The sample was split to run exploratory factor analysis and confirmatory factor analysis, finding support for a 62-item scale measuring all eight themes. The MY-Soc Scale was also supported by validity and reliability tests. The two studies advance the literature by increasing understanding of the racial-ethnic socialization experiences of Multiracial youth of diverse racial backgrounds. The MY-Soc Scale contributes an important tool for scholars and practitioners to learn which racial-ethnic socialization messages are promotive for Multiracial youth development in different contexts.
ContributorsAtkin, Annabelle L. (Author) / Yoo, Hyung Chol (Thesis advisor) / Jackson, Kelly F. (Committee member) / Tran, Alisia G.T.T. (Committee member) / White, Rebecca M.B. (Committee member) / Arizona State University (Publisher)
Created2020