Matching Items (474)
Description
Eigenvalues of the 3D critical point equation (∇u)ν = λν are normally computed numerically. In the letter, we present analytic solutions for 3D swirling strength in both compressible and incompressible flows. The solutions expose functional dependencies that cannot be seen in numerical solutions. To illustrate, we study the difference between using fluctuating and total velocity gradient tensors for vortex identification. Results show that mean shear influences vortex detection and that distortion can occur, depending on the strength of mean shear relative to the vorticity at the vortex center.
ContributorsChen, Huai (Author) / Adrian, Ronald (Author) / Zhong, Qiang (Author) / Wang, Xingkui (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2014-08-01
Description
The flexural behavior of epoxies was investigated by performing mechanical tests and applying statistical Weibull theory and analytical methods to the results. The effects of loading systems and environmental conditions were also considered. Three kinds of epoxies were studied: Epon E863, PRI 2002, and PR520. In total, 53 three-point-bending (3PB) Epon E863 samples and 26 3PB PR520 were tested immediately after curing, together with 26 four-point-bending (4PB) PRI2002 samples stored at 60°C and 90% Rh for 48 weeks. The Weibull parameters were estimated using both linear regression and the moments method. The statistical character of the Weibull model leads to uncertainty in the evaluated parameters, even for a large number of experiments. This study analyzed the ratio of flexural strength to tensile strength in bulk epoxy resin polymers. An analytical method previously developed by the authors to study the relationship between uniaxial tension/compression stress-strain curves and flexural load-deflection response was used to obtain the ratio. The results show that the Weibull model overpredicted the aforementioned ratio in different load arrangements.
ContributorsYekani Fard, Masoud (Author) / Raji, B. (Author) / Chattopadhyay, Aditi (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2014-12-01
Description
Identification of early damage in polymer composites is of great importance. We have incorporated cyclobutane-containing cross-linked polymers into an epoxy matrix, studied the effect on thermal and mechanical properties, and, more importantly, demonstrated early damage detection through mechanically induced fluorescence generation. Two cinnamate derivatives, 1,1,1-tris(cinnamoyloxymethyl) ethane (TCE) and poly(vinyl cinnamate) (PVCi), were photoirradiated to produce cyclobutane-containing polymer. The effects on the thermal and mechanical properties with the addition of cyclobutane-containing polymer into epoxy matrix were investigated. The emergence of cracks was detected by fluorescence at a strain level just beyond the yield point of the polymer blends, and the fluorescence intensified with accumulation of strain. Overall, the results show that damage can be detected through fluorescence generation along crack propagation.
ContributorsZou, Jin (Author) / Liu, Yingtao (Author) / Shan, Bohan (Author) / Chattopadhyay, Aditi (Author) / Dai, Lenore (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2014-09-01
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 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.
ContributorsQuintero, Jaime (Author) / Vittal, Vijay (Author) / Heydt, Gerald (Author) / Zhang, Hui (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School of Electrical, Computer and Energy Engineering (Contributor)
Created2014-09-01
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 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.
ContributorsFerry, David (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School of Electrical, Computer and Energy Engineering (Contributor)
Created2013
Learning Sparse Representations for Fruit-Fly Gene Expression Pattern Image Annotation and Retrieval
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, 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.
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
Description
The importance of second language learning in today’s ever-increasing globalized world is becoming ever more paramount. Despite seeming trends which indicate aversion to globalization, the international phenomenon which describes the connection made between peoples and cultures, will only increase its influence in coming years. With the advances globalization has made, it is becoming more important to learn and study foreign languages in order to keep abreast of this trend and not be left behind by globalization. Why electronic translation is not so viable in the long run (at least currently) is that culture and syntax are not things which can be simply ascertained via mediums such as application use. Due to the fact that advanced language proficiency is considered to be an integral piece towards stronger sentiments of “integration” (i.e. Syrian refugees integrating into EU and US) it is of more importance that increasing second language proficiency receives the adequate study and implementation to reflect a more cohesive globalized world. Accompanying this necessity is the simple fact that adult second language learners often struggle to overcome difficulty to the challenging yet rewarding task of learning and eventually mastering a second language.
To truly understand the difficulty some adult second language learners have with learning a second language it can be helpful to compare second language acquisition to how one naturally, and seemingly effortlessly in many cases, acquires their native language. How can a comparative analysis of how native speakers and adult second language learners each learn their first and second language respectively be successfully converted to a specific means of assisting adult second language learners achieve the highest level of possible fluency? In order to more accurately propose a viable solution to the overarching question, the following three questions have been proposed as a means to springboard into better understanding the nature of the main topic.
The points to consider while analyzing the main question throughout this analysis are as follows: How would it be best for an adult second language learner to achieve the same level off proficiency as a native speaker of a given language whom has been exposed to all of its intricacies since birth? At what point exactly is someone considered to have the same level of proficiency which a native speaker of a given language would have and how does that differ from being a heritage speaker? With the final supporting question being: What type of learning would be best suited in helping a heritage speaker (someone who learns a language in the home by virtue of their heritage) or adult second language learner to become highly proficient in a second language?
In order to propose a wide variety of integration between these questions with the conjoined purpose of answering the inquiry of this thesis, many different sources supporting each of the above questions will contain certain overlap, providing a clear basis for constructing a tri-fold argument in answering the thesis question as acutely as possible. In regards to the first question, the question of “proficiency” will be a subsection committed to understanding the nature of how language proficiency works and at what point (if ever) one can ever be considered “highly proficient” in a second language.
All three exploratory questions are compatible with a theory known as Critical Period Theory, a theory in linguistics proposed by Montreal neurologist Wilder Penfield, which states, “There is a critical age, before puberty, that one must learn language. If one has not learned to speak before puberty it is much more difficult, and sometimes impossible, to learn language and speak in a meaningful way.” The overlap which this method binds to Universal Grammar is a rather close-knit relationship. Research composed by certain linguists suggest that “children are born with a certain universal grammar wired into their brains.” This will be compared and cross-examined to a higher degree in a later section of the paper.
The importance of Universal Grammar in relation to Critical Period Theory cannot be overstated. Universal Grammar in relation to the second language Critical Period Theory will help explain at which point, someone is considered to be a “native speaker” of a given language. The third question posed of how would it be best for heritage and second language learners to increase their proficiency in a second language really touches on both of these theories in regards to at which age someone is exposed to a specific language in addition to how Universal Grammar affects the development of second language acquisition. In the realm of perpetually working towards mitigating an answer to this analysis’s thesis, the connecting thread or “roter Faden”, as it is said in German, will be the integrative domain the above questions will have on arriving to a clearer understanding of the nature of how a comparative analysis of second language learners and mother-tongue speakers can expedite the language learning process of second language learners, using techniques of native speakers which they inherently pick-up.
To truly understand the difficulty some adult second language learners have with learning a second language it can be helpful to compare second language acquisition to how one naturally, and seemingly effortlessly in many cases, acquires their native language. How can a comparative analysis of how native speakers and adult second language learners each learn their first and second language respectively be successfully converted to a specific means of assisting adult second language learners achieve the highest level of possible fluency? In order to more accurately propose a viable solution to the overarching question, the following three questions have been proposed as a means to springboard into better understanding the nature of the main topic.
The points to consider while analyzing the main question throughout this analysis are as follows: How would it be best for an adult second language learner to achieve the same level off proficiency as a native speaker of a given language whom has been exposed to all of its intricacies since birth? At what point exactly is someone considered to have the same level of proficiency which a native speaker of a given language would have and how does that differ from being a heritage speaker? With the final supporting question being: What type of learning would be best suited in helping a heritage speaker (someone who learns a language in the home by virtue of their heritage) or adult second language learner to become highly proficient in a second language?
In order to propose a wide variety of integration between these questions with the conjoined purpose of answering the inquiry of this thesis, many different sources supporting each of the above questions will contain certain overlap, providing a clear basis for constructing a tri-fold argument in answering the thesis question as acutely as possible. In regards to the first question, the question of “proficiency” will be a subsection committed to understanding the nature of how language proficiency works and at what point (if ever) one can ever be considered “highly proficient” in a second language.
All three exploratory questions are compatible with a theory known as Critical Period Theory, a theory in linguistics proposed by Montreal neurologist Wilder Penfield, which states, “There is a critical age, before puberty, that one must learn language. If one has not learned to speak before puberty it is much more difficult, and sometimes impossible, to learn language and speak in a meaningful way.” The overlap which this method binds to Universal Grammar is a rather close-knit relationship. Research composed by certain linguists suggest that “children are born with a certain universal grammar wired into their brains.” This will be compared and cross-examined to a higher degree in a later section of the paper.
The importance of Universal Grammar in relation to Critical Period Theory cannot be overstated. Universal Grammar in relation to the second language Critical Period Theory will help explain at which point, someone is considered to be a “native speaker” of a given language. The third question posed of how would it be best for heritage and second language learners to increase their proficiency in a second language really touches on both of these theories in regards to at which age someone is exposed to a specific language in addition to how Universal Grammar affects the development of second language acquisition. In the realm of perpetually working towards mitigating an answer to this analysis’s thesis, the connecting thread or “roter Faden”, as it is said in German, will be the integrative domain the above questions will have on arriving to a clearer understanding of the nature of how a comparative analysis of second language learners and mother-tongue speakers can expedite the language learning process of second language learners, using techniques of native speakers which they inherently pick-up.
ContributorsRoselius, Thomas Jacob (Author) / Lee, Sara (Thesis director) / Reves, Christiane (Committee member) / College of Public Service and Community Solutions (Contributor) / College of Integrative Sciences and Arts (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
This study examined the type and frequency of questions asked by attorneys in cases of children alleging sexual abuse. Of interest was whether child age would affect the questions asked. The participants included 25 child witnesses testifying in criminal trials in Maricopa County over a recent ten-year period. Children were placed into two groups: younger (five to seven-year-olds) and older (eight to nine-year-olds). Every question asked, and answer provided, during children's testimony, was systematically and reliably coded for the content of the interaction. Attorneys exhibited developmental sensitivity, varying the amount of question they asked across content areas by the age of the child. In addition, attorneys varied in what they asked about: the prosecution focused more on the plausibility of abuse, whereas the defense focused more on how others may have suggestively influenced the child's report. Both attorneys were equally concerned about the consistency of narratives. The findings from the present study have direct policy implications for how attorneys structure their arguments, both in an attempt to establish, and question, children's credibility in these important cases. Keywords: children, age, suggestibility, consistency, inconsistency, plausibility
ContributorsHogan, Caitlyn Rose (Author) / Stolzenberg, Stacia (Thesis director) / Fradella, Hank (Committee member) / College of Public Service and Community Solutions (Contributor) / School of Criminology and Criminal Justice (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Throughout history, terrorism has had major effects on tourists and tourism destinations that are targeted. When terrorists execute an attack in order to communicate a message, resulting impacts go far beyond lives lost. Included in these impacts is the fear that terror attacks leave on tourists, sometimes creating such an impression that tourists change travel plans as a result. Although there are many studies on destination image, risk perception, and decision-making, very few focus specifically on the millennial generation. Because millennials are changing the travel and tourism scene - as they now make up the largest percentage of the population \u2014 it is important for stakeholders in the tourism industry and DMOs to understand this shift and the implications that come with these changes. This study provides a qualitative analysis of millennials' views, attitudes, and beliefs regarding terror impacted tourist destinations. Specifically, it will explore how millennials develop their destination images, if millennials view international travel to be risky, and if millennials are willing to travel to terror impacted tourist destinations. Using focus group methodology, this study gathered data from students from a number of disciplines, genders, and travel experience, in order to understand the themes listed above. Analysis of the findings and implications for officials and DMOs follow, as well as a conclusion including limitations and recommendations for future studies.
ContributorsBacon, Laura Elizabeth (Author) / Buzinde, Christine (Thesis director) / Nyaupane, Gyan (Committee member) / Department of Management and Entrepreneurship (Contributor) / W. P. Carey School of Business (Contributor) / College of Public Service and Community Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
This study examines the The Disney College Program, a semester-long paid internship hosted by the Walt Disney Company employing more than 10,000 students each year. With over 120,000 alumni in the past 10 years, this program offers students housing and community building opportunities within the "Living" component, college credit courses within the "Learning" component, and on-the-job experience at Disneyland Resort and Walt Disney World theme parks through the "Earning" component. Specifically, the research focuses on Walt Disney World in Orlando, Florida. The researcher conducted a 39-question online survey prompting 1,749 responses from Disney College Program alumni to help answer the following research questions: (1) Who are Disney College Program Cast Members, (2) What is their level of satisfaction with the program, and (3) Are they influencers? This study uses theoretical elements (e.g. levels of adoption, influencers and brand loyalty) to describe influence and psychological effects to describe satisfaction (e.g. indoctrination, human motivation and Stockholm Syndrome). With the findings showing discrepancies between the ratings of "Living," "Learning," and "Earning" and the average overall rating, some questions arise about the program's tendencies to form tightly cohesive groups approaching elements of Stockholm Syndrome and cult-like ethos. Focusing on the 1,490 of 1,749 respondents from Walt Disney World in the past 10 years, the study concludes that Walt Disney World College Program alumni are not influencers nor advocates, but rather evangelists (i.e., zealous advocate) and loyalists.
ContributorsMcgowan, Sloane Shea (Author) / Matera, Fran (Thesis director) / Archer, Ciara (Committee member) / School of Community Resources and Development (Contributor) / Walter Cronkite School of Journalism and Mass Communication (Contributor) / College of Public Service and Community Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05