ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- Creators: Johnston, Carol
- Creators: Shen, Wei
- Creators: Zhang, Yanchao
Description
The body is capable of regulating hunger in several ways. Some of these hunger regulation methods are innate, such as genetics, and some, such as the responses to stress and to the smell of food, are innate but can be affected by body conditions such as BMI and physical activity. Further, some hunger regulation methods stem from learned behaviors originating from cultural pressures or parenting styles. These latter regulation methods for hunger can be grouped into the categories: emotion, environment, and physical. The factors that regulate hunger can also influence the incidence of disordered eating, such as eating in the absence of hunger (EAH). Eating in the absence of hunger can occur in one of two scenarios, continuous EAH or beginning EAH. College students are at a particularly high risk for EAH and weight gain due to stress, social pressures, and the constant availability of energy dense and nutrient poor food options. The purpose of this study is to validate a modified EAH-C survey in college students and to discover which of the three latent factors (emotion, environment, physical) best predicts continual and beginning EAH. To do so, a modified EAH-C survey, with additional demographic components, was administered to students at a major southwest university. This survey contained two questions, one each for continuing and beginning EAH, regarding 14 factors related to emotional, physical, or environmental reasons that may trigger EAH. The results from this study revealed that the continual and beginning EAH surveys displayed good internal consistency reliability. We found that for beginning and continuing EAH, although emotion is the strongest predictor of EAH, all three latent factors are significant predictors of EAH. In addition, we found that environmental factors had the greatest influence on an individual's likelihood to continue to eat in the absence of hunger. Due to statistical abnormalities and differing numbers of factors in each category, we were unable to determine which of the three factors exerted the greatest influence on an individual's likelihood to begin eating in the absence of hunger. These results can be utilized to develop educational tools aimed at reducing EAH in college students, and ultimately reducing the likelihood for unhealthy weight gain and health complications related to obesity.
ContributorsGoett, Taylor (Author) / Johnston, Carol (Thesis advisor) / Lee, Chong (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2013
Description
The rapid advancement of wireless technology has instigated the broad deployment of wireless networks. Different types of networks have been developed, including wireless sensor networks, mobile ad hoc networks, wireless local area networks, and cellular networks. These networks have different structures and applications, and require different control algorithms. The focus of this thesis is to design scheduling and power control algorithms in wireless networks, and analyze their performances. In this thesis, we first study the multicast capacity of wireless ad hoc networks. Gupta and Kumar studied the scaling law of the unicast capacity of wireless ad hoc networks. They derived the order of the unicast throughput, as the number of nodes in the network goes to infinity. In our work, we characterize the scaling of the multicast capacity of large-scale MANETs under a delay constraint D. We first derive an upper bound on the multicast throughput, and then propose a lower bound on the multicast capacity by proposing a joint coding-scheduling algorithm that achieves a throughput within logarithmic factor of the upper bound. We then study the power control problem in ad-hoc wireless networks. We propose a distributed power control algorithm based on the Gibbs sampler, and prove that the algorithm is throughput optimal. Finally, we consider the scheduling algorithm in collocated wireless networks with flow-level dynamics. Specifically, we study the delay performance of workload-based scheduling algorithm with SRPT as a tie-breaking rule. We demonstrate the superior flow-level delay performance of the proposed algorithm using simulations.
ContributorsZhou, Shan (Author) / Ying, Lei (Thesis advisor) / Zhang, Yanchao (Committee member) / Zhang, Junshan (Committee member) / Xue, Guoliang (Committee member) / Arizona State University (Publisher)
Created2013
Description
In October, 2009, participants of the Arizona Special Supplemental Nutrition Program for Women, Infants and Children (WIC) began receiving monthly Cash Value Vouchers (CVV) worth between six and 10 dollars towards the purchase of fresh fruits and vegetables. Data from the Arizona Department of Health Services (ADHS) showed CVV redemption rates in the first two years of the program were lower than the national average of 77% redemption. In response, the ADHS WIC Food List was expanded to also include canned and frozen fruits and vegetables. More recent data from ADHS suggest that redemption rates are improving, but variably exist among different WIC sub-populations. The purpose of this project was to identify themes related to the ease or difficulty of WIC CVV use amongst different categories of low-redeeming WIC participants. A total of 8 focus groups were conducted, four at a clinic in each of two Valley cities: Surprise and Mesa. Each of the four focus groups comprised one of four targeted WIC participant categories: pregnant, postpartum, breastfeeding, and children with participation ranging from 3-9 participants per group. Using the general inductive approach, recordings of the focus groups were transcribed, hand-coded and uploaded into qualitative analysis software resulting in four emergent themes including: interactions and shopping strategies, maximizing WIC value, redemption issues, and effect of rule change. Researchers identified twelve different subthemes related to the emergent theme of interactions and strategies to improve their experience, including economic considerations during redemption. Barriers related to interactions existed that made their purchase difficult, most notably anger from the cashier and other shoppers. However, participants made use of a number of strategies to facilitate WIC purchases or extract more value out of WIC benefits, such as pooling their CVV. Finally, it appears that the fruit and vegetable rule change was well received by those who were aware of the change. These data suggest a number of important avenues for future research, including verifying these themes are important within a larger, representative sample of Arizona WIC participants, and exploring strategies to minimize barriers identified by participants, such as use of electronic benefits transfer-style cards (EBT).
ContributorsBertmann, Farryl M. W (Author) / Wharton, Christopher (Christopher Mack), 1977- (Thesis advisor) / Ohri-Vachaspati, Punam (Committee member) / Johnston, Carol (Committee member) / Hampl, Jeffrey (Committee member) / Dixit-Joshi, Sujata (Committee member) / Barroso, Cristina (Committee member) / Arizona State University (Publisher)
Created2013
Description
The rapid advances in wireless communications and networking have given rise to a number of emerging heterogeneous wireless and mobile networks along with novel networking paradigms, including wireless sensor networks, mobile crowdsourcing, and mobile social networking. While offering promising solutions to a wide range of new applications, their widespread adoption and large-scale deployment are often hindered by people's concerns about the security, user privacy, or both. In this dissertation, we aim to address a number of challenging security and privacy issues in heterogeneous wireless and mobile networks in an attempt to foster their widespread adoption. Our contributions are mainly fivefold. First, we introduce a novel secure and loss-resilient code dissemination scheme for wireless sensor networks deployed in hostile and harsh environments. Second, we devise a novel scheme to enable mobile users to detect any inauthentic or unsound location-based top-k query result returned by an untrusted location-based service providers. Third, we develop a novel verifiable privacy-preserving aggregation scheme for people-centric mobile sensing systems. Fourth, we present a suite of privacy-preserving profile matching protocols for proximity-based mobile social networking, which can support a wide range of matching metrics with different privacy levels. Last, we present a secure combination scheme for crowdsourcing-based cooperative spectrum sensing systems that can enable robust primary user detection even when malicious cognitive radio users constitute the majority.
ContributorsZhang, Rui (Author) / Zhang, Yanchao (Thesis advisor) / Duman, Tolga Mete (Committee member) / Xue, Guoliang (Committee member) / Zhang, Junshan (Committee member) / Arizona State University (Publisher)
Created2013
Description
There are several visual dimensions of food that can affect food intake, example portion size, color, and variety. This dissertation elucidates the effect of number of pieces of food on preference and amount of food consumed in humans and motivation for food in animals. Chapter 2 Experiment 1 showed that rats preferred and also ran faster for multiple pieces (30, 10 mg pellets) than an equicaloric, single piece of food (300 mg) showing that multiple pieces of food are more rewarding than a single piece. Chapter 2 Experiment 2 showed that rats preferred a 30-pellet food portion clustered together rather than scattered. Preference and motivation for clustered food pieces may be interpreted based on the optimal foraging theory that animals prefer foods that can maximize energy gain and minimize the risk of predation. Chapter 3 Experiment 1 showed that college students preferred and ate less of a multiple-piece than a single-piece portion and also ate less in a test meal following the multiple-piece than single-piece portion. Chapter 3 Experiment 2 replicated the results in Experiment 1 and used a bagel instead of chicken. Chapter 4 showed that college students given a five-piece chicken portion scattered on a plate ate less in a meal and in a subsequent test meal than those given the same portion clustered together. This is consistent with the hypothesis that multiple pieces of food may appear like more food because they take up a larger surface area than a single-piece portion. All together, these studies show that number and surface area occupied by food pieces are important visual cues determining food choice in animals and both food choice and intake in humans.
ContributorsBajaj, Devina (Author) / Phillips, Elizabeth D. (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Bimonte-Nelson, Heather A. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Dietary protein is known to increase postprandial thermogenesis more so than carbohydrates or fats, probably related to the fact that amino acids have no immediate form of storage in the body and can become toxic if not readily incorporated into body tissues or excreted. It is also well documented that subjects report greater satiety on high- versus low-protein diets and that subject compliance tends to be greater on high-protein diets, thus contributing to their popularity. What is not as well known is how a high-protein diet affects resting metabolic rate over time, and what is even less well known is if resting metabolic rate changes significantly when a person consuming an omnivorous diet suddenly adopts a vegetarian one. This pilot study sought to determine whether subjects adopting a vegetarian diet would report decreased satiety or demonstrate a decreased metabolic rate due to a change in protein intake and possible increase in carbohydrates. Further, this study sought to validate a new device called the SenseWear Armband (SWA) to determine if it might be sensitive enough to detect subtle changes in metabolic rate related to diet. Subjects were tested twice on all variables, at baseline and post-test. Independent and related samples tests revealed no significant differences between or within groups for any variable at any time point in the study. The SWA had a strong positive correlation to the Oxycon Mobile metabolic cart but due to a lack of change in metabolic rate, its sensitivity was undetermined. These data do not support the theory that adopting a vegetarian diet results in a long-term change in metabolic rate.
ContributorsMoore, Amy (Author) / Johnston, Carol (Thesis advisor) / Appel, Christy (Thesis advisor) / Gaesser, Glenn (Committee member) / Arizona State University (Publisher)
Created2012
Description
The cyber-physical systems (CPS) are emerging as the underpinning technology for major industries in the 21-th century. This dissertation is focused on two fundamental issues in cyber-physical systems: network interdependence and information dynamics. It consists of the following two main thrusts. The first thrust is targeted at understanding the impact of network interdependence. It is shown that a cyber-physical system built upon multiple interdependent networks are more vulnerable to attacks since node failures in one network may result in failures in the other network, causing a cascade of failures that would potentially lead to the collapse of the entire infrastructure. There is thus a need to develop a new network science for modeling and quantifying cascading failures in multiple interdependent networks, and to develop network management algorithms that improve network robustness and ensure overall network reliability against cascading failures. To enhance the system robustness, a "regular" allocation strategy is proposed that yields better resistance against cascading failures compared to all possible existing strategies. Furthermore, in view of the load redistribution feature in many physical infrastructure networks, e.g., power grids, a CPS model is developed where the threshold model and the giant connected component model are used to capture the node failures in the physical infrastructure network and the cyber network, respectively. The second thrust is centered around the information dynamics in the CPS. One speculation is that the interconnections over multiple networks can facilitate information diffusion since information propagation in one network can trigger further spread in the other network. With this insight, a theoretical framework is developed to analyze information epidemic across multiple interconnecting networks. It is shown that the conjoining among networks can dramatically speed up message diffusion. Along a different avenue, many cyber-physical systems rely on wireless networks which offer platforms for information exchanges. To optimize the QoS of wireless networks, there is a need to develop a high-throughput and low-complexity scheduling algorithm to control link dynamics. To that end, distributed link scheduling algorithms are explored for multi-hop MIMO networks and two CSMA algorithms under the continuous-time model and the discrete-time model are devised, respectively.
ContributorsQian, Dajun (Author) / Zhang, Junshan (Thesis advisor) / Ying, Lei (Committee member) / Zhang, Yanchao (Committee member) / Cochran, Douglas (Committee member) / Arizona State University (Publisher)
Created2012
Description
Objective: Vinegar consumption studies have demonstrated possible therapeutic effects in reducing HbA1c and postprandial glycemia. The purpose of the study was to closely examine the effects of a commercial vinegar drink on daily fluctuations in fasting glucose concentrations and postprandial glycemia, and on HbA1c, in individuals at risk for Type 2 Diabetes Mellitus (T2D). Design: Thirteen women and one man (21-62 y; mean, 46.0±3.9 y) participated in this 12-week parallel-arm trial. Participants were recruited from a campus community and were healthy and not diabetic by self-report. Participants were not prescribed oral hypoglycemic medications or insulin; other medications were allowed if use was stable for > 3 months. Subjects were randomized to one of two groups: VIN (8 ounces vinegar drink providing 1.5 g acetic acid) or CON (1 vinegar pill providing 0.04 g acetic acid). Treatments were taken twice daily immediately prior to the lunch and dinner meals. Venous blood samples were drawn at trial weeks 0 and 12 to measure insulin, fasting glucose, and HbA1c. Subjects recorded fasting glucose and 2-h postprandial glycemia concentrations daily using a glucometer. Results: The VIN group showed significant reductions in fasting capillary blood glucose concentrations (p=0.05) that were immediate and sustained throughout the duration of the study. The VIN group had reductions in 2-h postprandial glucose (mean change of −7.6±6.8 mg/dL over the 12-week trial), but this value was not significantly different than that for the CON group (mean change of 3.3±5.3 mg/dL over the 12-week trial, p=0.232). HbA1c did not significantly change (p=0.702), but the reduction in HbA1c in the VIN group, −0.14±0.1%, may have physiological relevance. Conclusions: Significant reductions in HbA1c were not observed after daily consumption of a vinegar drink containing 1.5 g acetic acid in non-diabetic individuals. However, the vinegar drink did significantly reduce fasting capillary blood glucose concentrations in these individuals as compared to a vinegar pill containing 0.04 g acetic acid. These results support a therapeutic effect for vinegar in T2D prevention and progression, specifically in high-risk populations.
ContributorsQuagliano, Samantha (Author) / Johnston, Carol (Thesis advisor) / Appel, Christy (Committee member) / Dixon, Kathleen (Committee member) / Arizona State University (Publisher)
Created2013
Description
Objective: The purpose of this randomized parallel arm trial was to demonstrate the effects of daily fish oil supplementation (600mg per day for eight weeks) on body composition and body mass in young healthy women, aged 18-38, at a large southwestern university. Design: 26 non-obese (mean BMI 23.7±0.6 kg/m2), healthy women (18-38y; mean, 23.5±1.1 y) from a southwestern Arizona university campus community completed the study. Subjects were healthy, non-smokers, consuming less than 3.5 oz of fish per week according to self-report. Participants were randomized to one of two groups: FISH (600 mg omega-3 fatty acids provided in one gel capsule per day), or CON (1000 mg coconut oil placebo provided in one gel capsule per day). Body weight, BMI, and percent body fat were measured using a stadiometer and bioelectrical impedance scale at the screening visit and intervention weeks 1, 4, and 8. 24-hour dietary recalls were also performed at weeks 1 and 8. Results: 8 weeks of omega-3 fatty acid supplementation did not significantly alter body weight (p=0.830), BMI (p=1.00), or body fat percentage (p=0.600) as compared to placebo. Although not statistically significant, 24-hour dietary recalls performed at the beginning and end of the intervention revealed a trend towards increased caloric intake in the FISH group and decreased caloric intake in the CON group throughout the course of the study (p=0.069). If maintained, this difference in caloric intake could have physiological relevance. Conclusions: Omega-3 fatty acids do not significantly alter body weight or body composition in healthy young females. These findings do not refute the current recommendations for Americans to consume at least 8 oz of omega-3-rich seafood per week, supplying 250 mg EPA and DHA per day. More research is needed to investigate the potential for omega-3 fatty acids to modulate daily caloric intake.
ContributorsTeran, Bianca (Author) / Johnston, Carol (Thesis advisor) / Johnson, Melinda (Committee member) / Ohri-Vachaspati, Punam (Committee member) / Arizona State University (Publisher)
Created2013
Description
In 2002, a scientifically derived food guide pyramid for vegetarians, the Modified Food Guide for Lacto-ovo-vegetarians and Vegans was published and well received. Now that 10 years have passed, new scientific literature regarding the bioavailability of the nutrients of key concern in vegetarian diets has been published, and the graphical format of the nation's food guide has evolved from a pyramid shape into a circular plate. The objective of this research was to examine the post-2002 literature regarding the bioavailability of key nutrients in vegetarian diets; to use this information to update the recommendations made in the 2002 Modified Food Guide Pyramid for Lacto-ovo-vegetarians and Vegans; and to adapt this revised food plan to the new USDA MyPlate format. This process involved reviewing the scientific literature to determine if the DRIs for the nutrients of key concern in vegetarian diets are adequate for the vegetarian population and using this information to develop new recommendations for vegetarians if necessary, analyzing the nutrient content of representative foods in different food groups, reconfiguring the food groups so that foods with like nutrient components were grouped together, determining the number of servings of each food group required to meet vegetarians' nutrient requirements at three caloric levels, and developing sample menus. A circular plate graphic, the Vegetarian Plate, was designed to illustrate the recommendations of this updated food guide. This updated, scientifically derived food guide provides a sound base for diet planning for lacto-ovo-vegetarians and vegans. Further research is needed to assess the Vegetarian Plate's adequacy for children, pregnant and lactating women, athletes, and individuals with medical conditions or chronic diseases.
ContributorsFladell, Lauren (Author) / Johnston, Carol (Thesis advisor) / Vaughan, Linda (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2013