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- Genre: Masters Thesis
- Creators: Arizona State University
- Creators: Chakraborty, Bijeta
- Creators: Peterson, Cory
- Member of: ASU Electronic Theses and Dissertations
Description
Health knowledge alone does not appear to lead to sustained healthy behavior, suggesting the need for alternative methods for improving diet. Recent research shows a possible role of moral contexts of food production on diet related behaviors; however no studies have been conducted to specifically explore the relationship between moral constructs and food consumption. This study examined the relationship between fast food consumption and two measures of morality, Moral Foundations Questionnaire (MFQ), specifically harm/care and purity/sanctity foundations, and the Ethical Concern in food choice (EC) questionnaire, which includes animal welfare, environment protection, political values, and religion subscales. The study also examined the association between the measures of morality. 739 participants, primarily female (71.4%) and non-Hispanic Whites (76.5%), completed an online survey that included the MFQ, the EC questionnaire, and a brief fast food screener. Participant's morality scores in relation to their fast food consumption were examined first using bivariate ANOVA analysis and then using logistic regression to control for covariates. The MFQ foundations were compared with the EC subscales using Pearson correlation coefficient. Significant bivariate relationships were seen between fast food consumption and the MFQ's purity/sanctity foundation and EC's religion subscales (p<0.05). However these significant bivariate relationships did not hold after controlling for gender, race, university education, and religion in the logistic regression analysis. The foundations of the MFQ were positively correlated with the subscales for the EC questionnaire (r values ranging from .233-.613 (p<0.01). MFQ's purity/sanctity foundation and EC's religion subscale were the two most highly correlated (r=.613, p<0.01) showing that moral intuitions may be associated with eating decision making. The study did not find significant associations between MFQ or EC scores and fast food consumption.
ContributorsMartinelli, Sarah (Author) / Ohri-Vachaspati, Punam (Thesis advisor) / Hekler, Eric B. (Committee member) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2013
Description
The increase in obesity since the 1980's has been associated with fast-food consumption. In hopes that calorie labeling will be an effective tool to combat obesity, congress included a provision in the Patient Protection and Affordable Care Act of 2010 (ACA) that will require all restaurants with twenty or more locations to post calorie information for each menu item. Current research has provided mixed results regarding the effectiveness of calorie labeling, but overall seems to suggest that calorie labeling may only be effective among certain populations. In September, 2012 McDonald's began to post calorie labels on their menu boards before it was federally mandated under the ACA. This policy provided the opportunity to study the impact of calorie labeling on the purchasing behavior of McDonald's patrons. This cross-sectional study was designed to determine if self-perception of diet, self-perception of health, smoking, physical activity, fruit and vegetable intake, or knowledge of daily calorie requirements is associated with the likelihood of noticing or using calorie labels, or total calories purchased. In addition, relationships between noticing or using calorie labels with total calories purchased were also examined. Receipts and survey responses were collected from 330 participants who purchased food and beverage items from 27 different McDonald's locations within a 20 mile radius of downtown Phoenix, Arizona. Results indicated that only 16.1% of the sample reported using calorie labels, and those who reported using calorie labels purchased an average of 136 fewer calories. Multivariate analysis indicated there were no statistically significant relationships between self-perception of diet, self-perception of health, smoking, physical activity, fruit and vegetable intake, or knowledge of daily calorie requirements with the likelihood of noticing or using calorie labels, or total calories purchased. However, it is possible that the small sample size of participants using calorie labeling precluded any statistically significant relationships among these variables from emerging. Further research with larger sample sizes should be conducted, to investigate individual level factors that may be associated with use of calorie labeling.
ContributorsBrown, Alan (Author) / Ohri-Vachaspati, Punam (Thesis advisor) / Bruening, Meredith (Committee member) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Arizona State University (Publisher)
Created2013
Description
Efficiency of components is an ever increasing area of importance to portable applications, where a finite battery means finite operating time. Higher efficiency devices need to be designed that don't compromise on the performance that the consumer has come to expect. Class D amplifiers deliver on the goal of increased efficiency, but at the cost of distortion. Class AB amplifiers have low efficiency, but high linearity. By modulating the supply voltage of a Class AB amplifier to make a Class H amplifier, the efficiency can increase while still maintaining the Class AB level of linearity. A 92dB Power Supply Rejection Ratio (PSRR) Class AB amplifier and a Class H amplifier were designed in a 0.24um process for portable audio applications. Using a multiphase buck converter increased the efficiency of the Class H amplifier while still maintaining a fast response time to respond to audio frequencies. The Class H amplifier had an efficiency above the Class AB amplifier by 5-7% from 5-30mW of output power without affecting the total harmonic distortion (THD) at the design specifications. The Class H amplifier design met all design specifications and showed performance comparable to the designed Class AB amplifier across 1kHz-20kHz and 0.01mW-30mW. The Class H design was able to output 30mW into 16Ohms without any increase in THD. This design shows that Class H amplifiers merit more research into their potential for increasing efficiency of audio amplifiers and that even simple designs can give significant increases in efficiency without compromising linearity.
ContributorsPeterson, Cory (Author) / Bakkaloglu, Bertan (Thesis advisor) / Barnaby, Hugh (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Description
As part of the recently passed Patient Protection and Affordable Care Act, chain restaurants with 20 or more locations nationwide are required to post calorie information on menus and menu boards in order to help consumers make healthier decisions when dining out. Previous studies that have evaluated menu-labeling policies show mixed results and the majority have been conducted in urban cities along the east coast. This study was the first to look at the effectiveness of menu labeling in a southwest population. The primary objective of this cross-sectional study was to determine if noticing or using calorie menu labels in a fast food restaurant was associated with purchasing fewer calories. A second aim of this study was to evaluate the relationship between socio-demographic characteristics and the likelihood of noticing and using menu labeling. Customer receipts and survey data were collected from 329 participants using street-intercept survey methodology at 29 McDonald's locations in low- and high-income neighborhoods throughout the Phoenix metropolitan area. The study population was 63.5% male, 53.8% non-Hispanic white, and 50.8% low-income. Results showed that almost 60% of the study sample noticed calorie menu labeling and only 16% of participants reported using the information for food or beverage purchases. Income was the only socio-demographic characteristic that was associated with noticing menu labeling, with higher-income individuals being more likely to notice the information (p=0.029). Income was also found to be associated with using menu labels, with higher income individuals being more likely to use the information (p=0.04). Additionally, individuals with a bachelors degree or higher were more likely to use the information (p=0.023) and individuals aged 36 to 49 were least likely to use the information (p=0.046). There were no significant differences in average calories purchased among those who noticed menu labeling; however, those who reported using calorie information purchased 146 fewer calories than those who did not use the information (p=0.001). Based on these findings it is concluded that calorie menu labeling is an effective public policy and that nutrition education campaigns should accompany national menu labeling implementation in order to make the policy more effective across all socio-demographic groups.
ContributorsGreen, Jessie (Author) / Ohri-Vachaspati, Punam (Thesis advisor) / Bruening, Meg (Committee member) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Arizona State University (Publisher)
Created2014
Description
Class D Amplifiers are widely used in portable systems such as mobile phones to achieve high efficiency. The demands of portable electronics for low power consumption to extend battery life and reduce heat dissipation mandate efficient, high-performance audio amplifiers. The high efficiency of Class D amplifiers (CDAs) makes them particularly attractive for portable applications. The Digital class D amplifier is an interesting solution to increase the efficiency of embedded systems. However, this solution is not good enough in terms of PWM stage linearity and power supply rejection. An efficient control is needed to correct the error sources in order to get a high fidelity sound quality in the whole audio range of frequencies. A fundamental analysis on various error sources due to non idealities in the power stage have been discussed here with key focus on Power supply perturbations driving the Power stage of a Class D Audio Amplifier. Two types of closed loop Digital Class D architecture for PSRR improvement have been proposed and modeled. Double sided uniform sampling modulation has been used. One of the architecture uses feedback around the power stage and the second architecture uses feedback into digital domain. Simulation & experimental results confirm that the closed loop PSRR & PS-IMD improve by around 30-40 dB and 25 dB respectively.
ContributorsChakraborty, Bijeta (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
The humans-food relationship is a 2.5 million year old, symbiotic connection of “living together” which encouraged a “system of communication up and down the food chain” (Pollan, 2008). (Reardon, 2015). Many researchers agree that this connection is a critical foundation for a beneficial relationship with food and engaging in healthy eating behaviors (McKeown, 2010; Neumark-Stainer et al., 2007; Ristovski-Slejepcevic et al., 2008; Simontacchi, 2007). Against the backdrop of a steadily increasing obesity rate and associated spending, it is critical to approach this issue from a systematic perspective such as understanding the powers that impact the consumer-food relationship (Aronne and Havas, 2009). Experts agree that the rapid increase in convenience food environments has contributed to an obesogenic foodscape that has negatively impacted consumers’ understanding of and interactions with food, resulting in consumption of nutritionally poor food, over-nutrition and chronic illness (Brownell and Battle-Horgen, 2004; Nestle, 2002). Additionally, designers and researchers are beginning to recognize the influence the built environment can have on actions (Patel, 2012; Wansink, 2010), behaviors and attitudes (Gallagher, 1993), even hindering or encouraging one to partake in healthy behaviors (Mikkelsen, 2011; Story et al., 2008). The goal of this study is to understand modern built convenience food environment design and its potential to impact the consumer-food relationship. This study utilizes a heavily qualitative approach, structured by a grounded theory methodology due to the lack of existing research (Martin & Hanington, 2012; O’Leary, 2010) and triangulates utilizing an analysis of secondary research, environmental audit through observations and a survey. The final result will be a compilation of design suggestions, based on those findings, for designing a BCCFE that encourages a healthy relationship between the consumer and food.
ContributorsPlattner, Lainie (Author) / Takamura, John (Thesis advisor) / Heywood, William (Committee member) / Krahe, Jennifer E (Committee member) / Arizona State University (Publisher)
Created2015
Description
In this thesis, a digital input class D audio amplifier system which has the ability
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
ContributorsBai, Jing (Author) / Bakkaloglu, Bertan (Thesis advisor) / Arizona State University (Publisher)
Created2015