Matching Items (490)
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Description
The impact of increasing penetration of converter control-based generators (CCBGs) in a large-scale power system is assessed through a model based small signal stability analysis. Three test bed cases for the years 2010, 2020, and 2022 of the Western Electricity Coordinating Council (WECC) in the United States are used for

The impact of increasing penetration of converter control-based generators (CCBGs) in a large-scale power system is assessed through a model based small signal stability analysis. Three test bed cases for the years 2010, 2020, and 2022 of the Western Electricity Coordinating Council (WECC) in the United States are used for the analysis. Increasing penetration of wind-based Type 3 and wind-based Type 4 and PV Solar CCBGs is used in the tests. The participation and interaction of CCBGs and synchronous generators in traditional electromechanical interarea modes is analyzed. Two new types of modes dominated by CCBGs are identified. The characteristics of these new modes are described and compared to electromechanical modes in the frequency domain. An examination of the mechanism of the interaction between the CCBG control states and the synchronous generator control states is presented and validated through dynamic simulations. Actual system and forecast load data are used throughout.
Created2014-09-01
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Description
The Physics and Chemistry of Surfaces and Interfaces conference has maintained a focus on the interfacial and surface properties of materials since its initiation in 1974. The conference continues to be a major force in this field, bringing together scientists from a variety of disciplines to focus upon the science

The Physics and Chemistry of Surfaces and Interfaces conference has maintained a focus on the interfacial and surface properties of materials since its initiation in 1974. The conference continues to be a major force in this field, bringing together scientists from a variety of disciplines to focus upon the science of interfaces and surfaces. Here, a historical view of the development of the conference and a discussion of some of the themes that have been focal points for many years are presented.
Created2013
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Description
Background: National and international strategies to increase physical activity emphasize environmental and policy changes that can have widespread and long-lasting impact. Evidence from multiple countries using comparable methods is required to strengthen the evidence base for such initiatives. Because some environment and policy changes could have generalizable effects and others

Background: National and international strategies to increase physical activity emphasize environmental and policy changes that can have widespread and long-lasting impact. Evidence from multiple countries using comparable methods is required to strengthen the evidence base for such initiatives. Because some environment and policy changes could have generalizable effects and others may depend on each country's context, only international studies using comparable methods can identify the relevant differences. Methods: Currently 12 countries are participating in the International Physical Activity and the Environment Network (IPEN) study. The IPEN Adult study design involves recruiting adult participants from neighborhoods with wide variations in environmental walkability attributes and socioeconomic status (SES). Results: Eleven of twelve countries are providing accelerometer data and 11 are providing GIS data. Current projections indicate that 14,119 participants will provide survey data on built environments and physical activity and 7145 are likely to provide objective data on both the independent and dependent variables. Though studies are highly comparable, some adaptations are required based on the local context. Conclusions: This study was designed to inform evidence-based international and country-specific physical activity policies and interventions to help prevent obesity and other chronic diseases that are high in developed countries and growing rapidly in developing countries.
ContributorsKerr, Jacqueline (Author) / Sallis, James F. (Author) / Owen, Neville (Author) / De Bourdeaudhuij, Ilse (Author) / Cerin, Ester (Author) / Sugiyama, Takemi (Author) / Reis, Rodrigo (Author) / Sarmiento, Olga (Author) / Froemel, Karel (Author) / Mitas, Josef (Author) / Troelsen, Jens (Author) / Christiansen, Lars Breum (Author) / Macfarlane, Duncan (Author) / Salvo, Deborah (Author) / Schofield, Grant (Author) / Badland, Hannah (Author) / Guillen-Grima, Francisco (Author) / Aguinaga-Ontoso, Ines (Author) / Davey, Rachel (Author) / Bauman, Adrian (Author) / Saelens, Brian (Author) / Riddoch, Chris (Author) / Ainsworth, Barbara (Author) / Pratt, Michael (Author) / Schmidt, Tom (Author) / Frank, Lawrence (Author) / Adams, Marc (Author) / Conway, Terry (Author) / Cain, Kelli (Author) / Van Dyck, Delfien (Author) / Bracy, Nicole (Author) / College of Health Solutions (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2013
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Description
With the development of technology, using photographs to measure plate waste is an increasing
trend. These photographs are later analyzed when the data is being entered into a form or
system. Previously, these forms or systems have not been assessed for usability. This research
study looks at three iterations of a digital plate

With the development of technology, using photographs to measure plate waste is an increasing
trend. These photographs are later analyzed when the data is being entered into a form or
system. Previously, these forms or systems have not been assessed for usability. This research
study looks at three iterations of a digital plate waste observation system developed for the
School Lunch Study at Arizona State University. The System Usability Scale was used to
understand the functionality of the digital plate waste observation system. An area for free
responses was used to understand aspects of the system that were liked by research assistants
and what technical difficulties the research assistants encountered. These responses were used to
develop the next version of the digital plate waste observation system. Time to complete a task
was calculated to see the trends across all versions of the system. With each version, the System
Usability Scale scores increased along with the time to complete a task. This study found that
following the workflow of research assistants, being able to manipulate a photograph, having
menu items populated, and decreasing the amount of typing performed by adding selections to be
useful design aspects. Future digital plate waste observation systems can implement the
successful design aspects of this system, be aware of errors experienced, and implement helpful
features not found in this system. Future studies can look at the effect proctored training sessions
have on the time to complete a task and the relation of System Usability Scale scores with the
success of data entry.
ContributorsStott, Dahlia (Author) / Adams, Marc (Thesis director) / Barto, Henry (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2019-12
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Description
The objective of this study was to evaluate and compare the content of nutrition marketing materials within the cafeterias of schools in Central Arizona. By collecting photographs of marketing material from three elementary schools, one K-8 school, three middle schools and three high schools, 59 pieces of nutrition marketing were

The objective of this study was to evaluate and compare the content of nutrition marketing materials within the cafeterias of schools in Central Arizona. By collecting photographs of marketing material from three elementary schools, one K-8 school, three middle schools and three high schools, 59 pieces of nutrition marketing were gathered. The schools chosen were a convenience sample and selected from schools that were already participating in ASU' s School Lunch Study. The photographs were sorted by grade level and then coded quantitatively and qualitatively for their purpose, visual components, strategies used and relevance. Results from this novel study provided insight into prevalence, size, textual content, educational content, strategies for fruit and vegetable marketing, messaging and overall design of existing nutrition marketing within the sample schools. This study found that the prevalence of nutrition marketing within all school cafeterias appeared to be low, particularly within elementary and middle schools. Diverse types of messaging were present among elementary, middle and high schools and a variety of appeals were utilized with little consistency. Many of the strategies used in the nutrition marketing appeared disconnected from the population it was intended to appeal to. Educational components were notably lacking within middle school cafeterias but were often effectively integrated into high school nutrition marketing. The results are unique to this population, and further research is required to evaluate the content of existing nutrition material on a larger scale, so efforts can be made to improve the persuasiveness of nutrition marketing in promoting fruit and vegetable consumption.
Created2018-12
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Description
Background
African American women report insufficient physical activity and are disproportionally burdened by associated disease conditions; indicating the need for innovative approaches to promote physical activity in this underserved population. Social media platforms (i.e. Facebook) and text messaging represent potential mediums to promote physical activity. This paper reports the results of

Background
African American women report insufficient physical activity and are disproportionally burdened by associated disease conditions; indicating the need for innovative approaches to promote physical activity in this underserved population. Social media platforms (i.e. Facebook) and text messaging represent potential mediums to promote physical activity. This paper reports the results of a randomized pilot trial evaluating a theory-based (Social Cognitive Theory) multi-component intervention using Facebook and text-messages to promote physical activity among African American women.
Methods
Participants (N = 29) were randomly assigned to receive one of two multi-component physical activity interventions over 8 weeks: a culturally-relevant, Social Cognitive Theory-based, intervention delivered by Facebook and text message (FI) (n = 14), or a non-culturally tailored print-based intervention (PI) (n = 15) consisting of promotion brochures mailed to their home. The primary outcome of physical activity was assessed by ActiGraph GT3X+ accelerometers. Secondary outcomes included self-reported physical activity, physical activity-related psychosocial variables, and participant satisfaction.
Results
All randomized participants (N = 29) completed the study. Accelerometer measured physical activity showed that FI participants decreased sedentary time (FI = −74 minutes/week vs. PI = +118 minute/week) and increased light intensity (FI = +95 minutes/week vs. PI = +59 minutes/week) and moderate-lifestyle intensity physical activity (FI = + 27 minutes/week vs. PI = −34 minutes/week) in comparison to PI participants (all P’s < .05). No between group differences for accelerometer measured moderate-to-vigorous intensity physical activity were observed (P > .05). Results of secondary outcomes showed that in comparison to the PI, FI participants self-reported greater increases in moderate-to-vigorous physical activity (FI = +62 minutes/week vs. PI = +6 minutes/week; P = .015) and had greater enhancements in self-regulation for physical activity (P < .001) and social support from family for physical activity (P = .044). Satisfaction with the FI was also high: 100% reported physical activity-related knowledge gains and 100% would recommend the program to a friend.
Conclusions
A culturally-relevant Facebook and text message delivered physical activity program was associated with several positive outcomes, including decreased sedentary behavior, increased light- and moderate-lifestyle intensity physical activity, enhanced psychosocial outcomes, and high participant satisfaction. Future studies with larger samples are warranted to further explore the efficacy of technology-based approaches to promote physical activity among African American women.
Created2015-03-27
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Description
Background
Increasing empirical evidence supports associations between neighborhood environments and physical activity. However, since most studies were conducted in a single country, particularly western countries, the generalizability of associations in an international setting is not well understood. The current study examined whether associations between perceived attributes of neighborhood environments and physical

Background
Increasing empirical evidence supports associations between neighborhood environments and physical activity. However, since most studies were conducted in a single country, particularly western countries, the generalizability of associations in an international setting is not well understood. The current study examined whether associations between perceived attributes of neighborhood environments and physical activity differed by country.
Methods
Population representative samples from 11 countries on five continents were surveyed using comparable methodologies and measurement instruments. Neighborhood environment × country interactions were tested in logistic regression models with meeting physical activity recommendations as the outcome, adjusted for demographic characteristics. Country-specific associations were reported.
Results
Significant neighborhood environment attribute × country interactions implied some differences across countries in the association of each neighborhood attribute with meeting physical activity recommendations. Across the 11 countries, land-use mix and sidewalks had the most consistent associations with physical activity. Access to public transit, bicycle facilities, and low-cost recreation facilities had some associations with physical activity, but with less consistency across countries. There was little evidence supporting the associations of residential density and crime-related safety with physical activity in most countries.
Conclusion
There is evidence of generalizability for the associations of land use mix, and presence of sidewalks with physical activity. Associations of other neighborhood characteristics with physical activity tended to differ by country. Future studies should include objective measures of neighborhood environments, compare psychometric properties of reports across countries, and use better specified models to further understand the similarities and differences in associations across countries.
ContributorsDing, Ding (Author) / Adams, Marc (Author) / Sallis, James F. (Author) / Norman, Gregory J. (Author) / Hovell, Melbourn F. (Author) / Chambers, Christina D. (Author) / Hofstetter, C. Richard (Author) / Bowles, Heather R. (Author) / Hagstromer, Maria (Author) / Craig, Cora L. (Author) / Fernando Gomez, Luis (Author) / De Bourdeaudhuij, Ilse (Author) / Macfarlane, Duncan J. (Author) / Ainsworth, Barbara (Author) / Bergman, Patrick (Author) / Bull, Fiona C. (Author) / Carr, Harriette (Author) / Klasson-Heggebo, Lena (Author) / Inoue, Shigeru (Author) / Murase, Norio (Author) / Matsudo, Sandra (Author) / Matsudo, Victor (Author) / McLean, Grant (Author) / Sjostrom, Michael (Author) / Tomten, Heidi (Author) / Lefevre, Johan (Author) / Volbekiene, Vida (Author) / Bauman, Adrian E. (Author) / College of Health Solutions (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2013-05-14
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Description
Background
Neighborhood environment studies of physical activity (PA) have been mainly single-country focused. The International Prevalence Study (IPS) presented a rare opportunity to examine neighborhood features across countries. The purpose of this analysis was to: 1) detect international neighborhood typologies based on participants’ response patterns to an environment survey and 2)

Background
Neighborhood environment studies of physical activity (PA) have been mainly single-country focused. The International Prevalence Study (IPS) presented a rare opportunity to examine neighborhood features across countries. The purpose of this analysis was to: 1) detect international neighborhood typologies based on participants’ response patterns to an environment survey and 2) to estimate associations between neighborhood environment patterns and PA.
Methods
A Latent Class Analysis (LCA) was conducted on pooled IPS adults (N=11,541) aged 18 to 64 years old (mean=37.5 ±12.8 yrs; 55.6% women) from 11 countries including Belgium, Brazil, Canada, Colombia, Hong Kong, Japan, Lithuania, New Zealand, Norway, Sweden, and the U.S. This subset used the Physical Activity Neighborhood Environment Survey (PANES) that briefly assessed 7 attributes within 10–15 minutes walk of participants’ residences, including residential density, access to shops/services, recreational facilities, public transit facilities, presence of sidewalks and bike paths, and personal safety. LCA derived meaningful subgroups from participants’ response patterns to PANES items, and participants were assigned to neighborhood types. The validated short-form International Physical Activity Questionnaire (IPAQ) measured likelihood of meeting the 150 minutes/week PA guideline. To validate derived classes, meeting the guideline either by walking or total PA was regressed on neighborhood types using a weighted generalized linear regression model, adjusting for gender, age and country.
Results
A 5-subgroup solution fitted the dataset and was interpretable. Neighborhood types were labeled, “Overall Activity Supportive (52% of sample)”, “High Walkable and Unsafe with Few Recreation Facilities (16%)”, “Safe with Active Transport Facilities (12%)”, “Transit and Shops Dense with Few Amenities (15%)”, and “Safe but Activity Unsupportive (5%)”. Country representation differed by type (e.g., U.S. disproportionally represented “Safe but Activity Unsupportive”). Compared to the Safe but Activity Unsupportive, two types showed greater odds of meeting PA guideline for walking outcome (High Walkable and Unsafe with Few Recreation Facilities, OR= 2.26 (95% CI 1.18-4.31); Overall Activity Supportive, OR= 1.90 (95% CI 1.13-3.21). Significant but smaller odds ratios were also found for total PA.
Conclusions
Meaningful neighborhood patterns generalized across countries and explained practical differences in PA. These observational results support WHO/UN recommendations for programs and policies targeted to improve features of the neighborhood environment for PA.
ContributorsAdams, Marc (Author) / Ding, Ding (Author) / Sallis, James F. (Author) / Bowles, Heather R. (Author) / Ainsworth, Barbara (Author) / Bergman, Patrick (Author) / Bull, Fiona C. (Author) / Carr, Harriette (Author) / Craig, Cora L. (Author) / De Bourdeaudhuij, Ilse (Author) / Fernando Gomez, Luis (Author) / Hagstromer, Maria (Author) / Klasson-Heggebo, Lena (Author) / Inoue, Shigeru (Author) / Lefevre, Johan (Author) / Macfarlane, Duncan J. (Author) / Matsudo, Sandra (Author) / Matsudo, Victor (Author) / McLean, Grant (Author) / Murase, Norio (Author) / Sjostrom, Michael (Author) / Tomten, Heidi (Author) / Volbekiene, Vida (Author) / Bauman, Adrian (Author) / College of Health Solutions (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2013-03-07
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Description
Background
Fruit fly embryogenesis is one of the best understood animal development systems, and the spatiotemporal gene expression dynamics in this process are captured by digital images. Analysis of these high-throughput images will provide novel insights into the functions, interactions, and networks of animal genes governing development. To facilitate comparative analysis,

Background
Fruit fly embryogenesis is one of the best understood animal development systems, and the spatiotemporal gene expression dynamics in this process are captured by digital images. Analysis of these high-throughput images will provide novel insights into the functions, interactions, and networks of animal genes governing development. To facilitate comparative analysis, web-based interfaces have been developed to conduct image retrieval based on body part keywords and images. Currently, the keyword annotation of spatiotemporal gene expression patterns is conducted manually. However, this manual practice does not scale with the continuously expanding collection of images. In addition, existing image retrieval systems based on the expression patterns may be made more accurate using keywords.
Results
In this article, we adapt advanced data mining and computer vision techniques to address the key challenges in annotating and retrieving fruit fly gene expression pattern images. To boost the performance of image annotation and retrieval, we propose representations integrating spatial information and sparse features, overcoming the limitations of prior schemes.
Conclusions
We perform systematic experimental studies to evaluate the proposed schemes in comparison with current methods. Experimental results indicate that the integration of spatial information and sparse features lead to consistent performance improvement in image annotation, while for the task of retrieval, sparse features alone yields better results.
ContributorsYuan, Lei (Author) / Woodard, Alexander (Author) / Ji, Shuiwang (Author) / Jiang, Yuan (Author) / Zhou, Zhi-Hua (Author) / Kumar, Sudhir (Author) / Ye, Jieping (Author) / Biodesign Institute (Contributor) / Center for Evolution and Medicine (Contributor) / Ira A. Fulton Schools of Engineering (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor)
Created2012-05-23
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Description
It is well established that physical activity (PA) directly correlates with many health benefits, especially when active habits are formed during childhood and adolescence. PA practiced in adolescence has been seen to carry into adulthood, helping to combat a host of chronic diseases, such as obesity and diabetes. However, in

It is well established that physical activity (PA) directly correlates with many health benefits, especially when active habits are formed during childhood and adolescence. PA practiced in adolescence has been seen to carry into adulthood, helping to combat a host of chronic diseases, such as obesity and diabetes. However, in recent years there has been a steady decline in PA among adolescents, followed by a resulting rise in sedentary behavior. Walking Intervention Through Texting for Adolescents, or WalkIT-A, was an 11.5-week intervention that built upon behavioral theory to provide an incentive-based, adaptive, physical activity intervention to inactive adolescents. The goal of this study was to investigate an intervention which combined walking with pointed behavior change strategies to incite a larger increase in PA. Using single-case, reversal (ABA) design, the study was aimed at shaping physical activity behavior in adolescents aged 12-17 through a mobile health intervention that paired adaptive goal setting with financial incentives to increase step count. The intervention was delivered using a semi-automated texting, mobile-Health (mHealth) platform, which incorporated FitBit tracking technology, adaptive goals, motivational messages, performance feedback, and points/incentives. It was hypothesized that during the adaptive intervention phase participants would increase both steps per day and active minutes compared to baseline values. Upon conclusion of the study, the three adolescent participants exhibited increased steps and active minutes during the intervention period compared to baseline and withdrawal phases. However, the specific trends identified suggest the need for future research to incorporate even stronger intervention components to overcome PA "drop-off" midway through the intervention, along with other external, environmental influencers. Despite this need, the use of adaptive goal setting combined with incentives can be an effective means to incite PA behavior change in adolescents.
ContributorsVan Bussum, Courtney Jessica (Author) / Adams, Marc (Thesis director) / Forzani, Erica (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2016-12