Matching Items (4)
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- All Subjects: Measurement
- All Subjects: Stress
- Genre: Academic theses
- Creators: Ainsworth, Barbara
- Resource Type: Text
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
Introduction: Several faith-based or faith-placed programs have focused on the physical dimension of wellness in efforts to improve health by increasing physical activity and improving diet behaviors. However, these programs were not designed to intervene on the mental dimension of wellness which is critical for stress reduction and health behavior change. Purpose: To evaluate the feasibility of a spirituality-based stress reduction and health behavior change intervention using the Spiritual Framework of Coping (SFC) model. Methods: This study was a quasi-experimental one group pretest posttest design. The study was a total of eight weeks conducted at a non-denominational Christian church. Participants were recruited from the church through announcements and flyers. The Optimal Health program met once a week for 1.5 hours with weekly phone calls during an additional four week follow-up period. Feasibility was assessed by the acceptability, demand, implementation, practicality, integration, and limited efficacy of the program. Analysis: Frequencies for demographics were assessed. Statistical analyses of feasibility objectives were assessed by frequencies and distribution of responses to feasibility evaluations. Limited efficacy of pretest and posttest measures were conducted using paired t-test (p <.05). Results: The Optimal Health Program was positively accepted by participants. The demand for the program was shown with average attendance of 78.7%. The program was successfully implemented as shown by meeting session objectives and 88% homework completion. The program was both practical for the intended participants and was successfully integrated within the existing environment. Limited efficacy changes within the program were mostly non-significant. Conclusion: This study tested the feasibility of implementing the Optimal Health program that specifically targeted the structural components of the Spiritual Framework of Coping Model identified to create meaning making and enhance well-being. This program may ultimately be used to help individuals improve and balance the spiritual, mental, and physical dimensions of wellness. However, length of study and limited efficacy measures will need to be reevaluated for program success.
ContributorsWalker, Jenelle R (Author) / Swan, Pamela (Thesis advisor) / Ainsworth, Barbara (Committee member) / Chisum, Jack (Committee member) / Fleury, Julie (Committee member) / Hooker, Steven (Committee member) / Arizona State University (Publisher)
Created2012
Description
It is broadly accepted that physical activity provides substantial health benefits. Despite strong evidence, approximately 60% to 95% of US adults are insufficiently active to obtain these health benefits. This dissertation explored five projects that examined the measurement properties and methodology for a variety of physical activity assessment methods. Project one identified validity evidence for the new MyWellness Key accelerometer in sixteen adults. The MyWellness Key demonstrated acceptable validity evidence when compared to a criterion accelerometer during graded treadmill walking and in free-living settings. This supports the use of the MyWellness Key accelerometer to measure physical activity. Project two evaluated validity (study 1) and test-retest reliability evidence (study 2) of the Global Physical Activity Questionnaire (GPAQ) in a two part study. The GPAQ was compared to direct and indirect criterion measures including object and subjective physical activity instruments. These data provided preliminary validity and reliability evidence for the GPAQ that support its use to assess physical activity. Project three investigated the optimal h.d-1 of accelerometer wear time needed to assess daily physical activity. Using a semi-simulation approach, data from 124 participants were used to compare 10-13 h.d-1 to the criterion 14 h.d-1. This study suggested that a minimum accelerometer wear time of 13 h.d-1 is needed to provide a valid measure of daily physical activity. Project four evaluated validity and reliability evidence of a novel method (Movement and Activity in Physical Space [MAPS] score) that combines accelerometer and GPS data to assess person-environment interactions. Seventy-five healthy adults wore an accelerometer and GPS receiver for three days to provide MAPS scores. This study provided evidence for use of a MAPS score for future research and clinical use. Project five used accelerometer data from 1,000 participants from the 2005-2006 National Health and Nutrition Examination Study. A semi-simulation approach was used to assess the effect of accelerometer wear time (10-14 h.d-1) on physical activity data. These data showed wearing for 12 h.d-1 or less may underestimate time spent in various intensities of physical activity.
ContributorsHerrmann, Stephen (Author) / Ainsworth, Barbara (Thesis advisor) / Gaesser, Glenn (Committee member) / Der Ananian, Cheryl (Committee member) / Kang, Minsoo (Committee member) / Vega-Lopez, Sonia (Committee member) / Arizona State University (Publisher)
Created2011
Description
Physical inactivity is a continuing public health crisis because of its negative effects on health (e.g. hypertension, cardiovascular disease, type II diabetes). To combat the rising prevalence of these non-communicable diseases, physical activity (PA) promotion is a public health priority. However, current programs seem to be ineffective in the long-term promotion of PA. Resultingly new, effective interventions are needed. Recent studies have established a link between mindfulness and PA engagement. Based on the current literature, the present study sought to investigate the associations between trait mindfulness, behavioral regulation towards exercise, exercise intention, stress, and self-reported PA. This study also examined whether trait mindfulness was independently associated with meeting weekly, leisure-time, moderate-to-vigorous PA [MVPA] recommendations in university undergraduate students after controlling for demographic characteristics, past PA experience, exercise intention, stress, and motivation.
The study used a cross-sectional design and participants consisted of 180 undergraduate university students (aged 18 to 24 years). Participants completed a one-time survey that assessed demographic characteristics, trait mindfulness, behavioral regulation toward exercise, exercise intention, perceived stress and PA. Bivariate associations between the variables were assessed with Pearson or Spearman correlations. A logistic regression analysis was conducted to determine which variables were independently associated with meeting weekly, leisure-time MVPA guidelines. Results of this study found weak positive associations between the mindfulness domain of acceptance and leisure time MVPA ( = .168, p < .05), no associations between mindfulness and transportation PA, and negative associations between mindfulness (MAAS, = –.238, p < .01; acceptance, = –.175, p < .05) and sitting time. Results of logistic regression found that only relative autonomy (OR = 1.085, 95% CI [1.008, 1.168], p = .030) and intention (OR = 2.193, 95% CI [1.533, 3.138], p < .0001) were independently associated with meeting weekly, leisure- time MVPA recommendations. The results of this study show that while there is only a weak direct relationship between trait mindfulness and PA, mindfulness may be related with other factors associated with PA. More research is needed in order to better understand the potential mechanisms behind the results found in this, and past, studies.
The study used a cross-sectional design and participants consisted of 180 undergraduate university students (aged 18 to 24 years). Participants completed a one-time survey that assessed demographic characteristics, trait mindfulness, behavioral regulation toward exercise, exercise intention, perceived stress and PA. Bivariate associations between the variables were assessed with Pearson or Spearman correlations. A logistic regression analysis was conducted to determine which variables were independently associated with meeting weekly, leisure-time MVPA guidelines. Results of this study found weak positive associations between the mindfulness domain of acceptance and leisure time MVPA ( = .168, p < .05), no associations between mindfulness and transportation PA, and negative associations between mindfulness (MAAS, = –.238, p < .01; acceptance, = –.175, p < .05) and sitting time. Results of logistic regression found that only relative autonomy (OR = 1.085, 95% CI [1.008, 1.168], p = .030) and intention (OR = 2.193, 95% CI [1.533, 3.138], p < .0001) were independently associated with meeting weekly, leisure- time MVPA recommendations. The results of this study show that while there is only a weak direct relationship between trait mindfulness and PA, mindfulness may be related with other factors associated with PA. More research is needed in order to better understand the potential mechanisms behind the results found in this, and past, studies.
ContributorsNapolitano, Vinson (Author) / Der Ananian, Cheryl (Thesis advisor) / Sebren, Ann (Committee member) / Ainsworth, Barbara (Committee member) / Arizona State University (Publisher)
Created2019