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Laboratory Evaluation of Hot-Mix Asphalt Concrete Fatigue Cracking ResistanceJamison, Brandon Parker 2010 December 1900 (has links)
The recent changes in the Texas Department of Transportation (TxDOT) hot mix asphalt (HMA) mix design procedures to ensure that the mixture types routinely used on Texas highways are not prone to rutting raised concerns that these mixture types are now more susceptible to fatigue cracking. The primary goal of this study was to evaluate fatigue cracking test methods and recommend that which is both simple and robust, especially in qualifying commonly used Texas mixture types. One way to minimize fatigue cracking is through material screening and selection of appropriate mix designs that are representative of fatigue-resistant HMA mixes. However, there are not many standardized laboratory fracture resistance tests that have been universally adopted for routine mix design and/or screening purposes for HMA fatigue resistance. In this study, four different fracture test methods: the Overlay Tester (OT), Direct Tension (DT), Indirect Tension (IDT), and Semicircular Bending (SCB) tests were comparatively evaluated for their potential application as surrogate tests for routine fracture resistance evaluation and screening of HMA mixes in the laboratory. The evaluation criteria included: rationality of the test concept and correlation to field performance, repeatability and variability, simplicity and practicality of the sample fabrication process, and simplicity of data analysis. Results and key findings based on the laboratory fatigue resistance characterization of various commonly used Texas coarse- and fine-graded HMA mixes (Type B, C, and D) are presented in this paper. Overall, preliminary findings indicated that no monotonically-loaded test would be appropriate as a surrogate fatigue resistance test; however, the SCB test showed potential as a repeated-loading test. Suggested SCB test improvements include developing the repeated SCB test protocol, determining the appropriate failure criterion, and correlating laboratory performance to field performance.
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Predicting the impact of prior physical activity on shooting performance / Prediktion av tidigare fysisk aktivitets inverkan på skytteprestandaBerkman, Anton, Andersson, Gustav January 2019 (has links)
The objectives of this thesis were to develop a machine learning tool-chain and to investigate the relationship between heart rate and trigger squeeze and shooting accuracy when firing a handgun in a simulated environment. There are several aspects that affects the accuracy of a shooter. To accelerate the learning process and to complement the instructors, different sensors can be used by the shooter. By extracting sensor data and presenting this to the shooter in real-time the rate of improvement can potentially be accelerated. An experiment which replicated precision shooting was conducted at SAAB AB using their GC-IDT simulator. 14 participants with experience ranging from zero to over 30 years participated. The participants were randomly divided into two groups where one group started the experiment with a heart rate of at least 150 beats per minute. The iTouchGlove2.3 was used to measure trigger squeeze and Polar H10 heart rate belt was used to measure heart rate. Random forest regression was then used to predict accuracy on the data collected from the experiment. A machine learning tool-chain was successfully developed to process raw sensor data which was then used by a random forest regression algorithm to form a prediction. This thesis provides insights and guidance for further experimental explorations of handgun exercises and shooting performance.
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Citation Context Analysis of Theory Use in Instructional Design and Technology Academic ArticlesGentry, Wendy Ann 03 November 2016 (has links)
Citations allow researchers to define relationships across articles and develop arguments by building on the work of others. This study explores citation of theory symbols in Instructional Design and Technology (IDT) academic articles. The term theory symbol is used to define a concept that, after its original publication, is subsequently incorporated by later writers through citation. Exploring the citation history of the seminal publications makes it possible to trace theory symbol use over time and thus to trace its dissemination in the field. A typology of theory symbol use in IDT academic publication is developed through a citation context analysis (CCA) of a sample of articles published in Educational Technology Research and Development (ETRD) and its predecessor journals (1953–2012) which incorporate theory symbols through citation. This analysis contributes to an understanding of how theory has shaped IDT disciplinary knowledge and augments discourse analysis and bibliometrics by examining the context in which theory is incorporated into academic publication. / Ph. D.
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Mobile Search : An empirical investigation of the next big thingBäcke, Louise, Hansen, Ellinor, Johansson, Linnea January 2012 (has links)
The remarkable spread of the Internet has generated new opportunities for companies to promote themselves and communicate with their customers. The most used Internet service of finding information today is search engines (e.g. Google, Bing, Yahoo) were almost three million searches are preformed every minute worldwide. This trend has led to an importance for companies having their websites visible on these search engines. In addition, people tend to be more and more on the go and are searching with their smartphones instead of traditional personal computer (PC). Meaning that companies’ websites can be available for customers 24 hour a day, 7 days a week, independent on customers location. Consequently, companies have the possibilities to reach the attention of customers when they actually search for a product/service and are therefore most likely to purchase. In this thesis a marketing strategy has been developed for managers regarding how to master this new communication tool, in order to reach success and competitive advantage. This strategy was developed by investigate in what characteristics and functions users desire when searching with their smartphone. Together with three hypotheses tested if the perceived user-friendliness, relative advantage and compatibility within mobile search have a positive affect on the intention of use this new technology. In this bachelor thesis a survey was conducted among people in generation C living in Sweden, which resulted in 397 completed responses. The hypotheses were tested with use of a regression analysis and the findings were that the relative advantage and compatibility in mobile search has a positive affect on the intention of use. Therefore, this thesis suggests companies to develop their mobile search engine marketing strategy with the aim of delivering value and satisfying the customer. Moreover, this thesis recommend managers to keep their mobile website quick, relevant and making sure having valuable and informative information about their business in the description text visible to users in the search engine hit list. Finally, the majority of the population does already act on this new market and it is therefore of great importance for companies satisfying these users in order to stay competitive.
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Unidimensional and Evolution Methods for Optimal TransportationBonnotte, Nicolas 16 December 2013 (has links) (PDF)
In dimension one, optimal transportation is rather straightforward. The easiness with which a solution can be obtained in that setting has recently been used to tackle more general situations, each time thanks to the same method. First, disintegrate your problem to go back to the unidimensional case, and apply the available 1D methods to get a first result; then, improve it gradually using some evolution process.This dissertation explores that direction more thoroughly. Looking back at two problems only partially solved this way, I show how this viewpoint in fact allows to go even further.The first of these two problems concerns the computation of Yann Brenier's optimal map. Guillaume Carlier, Alfred Galichon, and Filippo Santambrogio found a new way to obtain it, thanks to an differential equation for which an initial condition is given by the Knothe--Rosenblatt rearrangement. (The latter is precisely defined by a series of unidimensional transformations.) However, they only dealt with discrete target measures; I~generalize their approach to a continuous setting. By differentiation, the Monge--Ampère equation readily gives a PDE satisfied by the Kantorovich potential; but to get a proper initial condition, it is necessary to use the Nash--Moser version of the implicit function theorem.The basics of optimal transport are recalled in the first chapter, and the Nash--Moser theory is exposed in chapter 2. My results are presented in chapter 3, and numerical experiments in chapter 4.The last chapter deals with the IDT algorithm, devised by François Pitié, Anil C. Kokaram, and Rozenn Dahyot. It builds a transport map that seems close enough to the optimal map for most applications. A complete mathematical understanding of the procedure is, however, still lacking. An interpretation as a gradient flow in the space of probability measures is proposed, with the sliced Wasserstein distance as the functional. I also prove the equivalence between the sliced and usual Wasserstein distances.
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Adoção e uso de tecnologia : uma análise entre as características de inovação tecnológica e o comportamento dos docentes em torno do uso do Moodle / Technology adoption and use: a analysis between the characteristics of technological innovation and the teacher s behavior around use of Moodle.Machado, Petruska de Araujo 25 February 2011 (has links)
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Previous issue date: 2011-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this study, the research model based on the technology acceptance model (TAM) (DAVIS et al., 1989) and innovation diffusion theory (IDT) (ROGERS, 2003) was used to analyze the relation between the characteristics of innovation and teacher s behavior in the process of adoption and use of Moodle in the undergraduate courses at distance. Survey was applied with 162 teachers at distance of Universidade Federal da Paraíba Virtual, issue focusing on the perceived characteristics of innovation, attitude and intention about the use of Moodle. Multivariate statistical techniques were performed: 1) content-vality to analyze the complete structure of scale for relevance and representativeness of items and to verify which items refer to construct in question; 2) exploratory factory analysis to know the structure of interrelationship of the original variables of IDT; 3) confirmatory factor analysis to guarantee conceptual validity for the pattern observed; 4) coefficient alpha to verify the homogeneity of set of items; 5) ANOVA to verify the likely differences between the groups of respondents; and 6) multiple regression analysis to analyze the relation between constructs. Results showed that not all factors of IDT had effect on attitude and intention. Only three constructs had significant effect on attitude and/or intention: relative advantage+compatibility for work style (β = 0,792), visibility (β = 0,166) and result demonstrability (β = 0,152). Moreover, teachers had a positive attitude in relation to use of Moodle and a positive intention in relation to use in the future. It was not possible to confirm all the relation of TAM, probably this verification was been compromised for some problems in the measurement process, thus, the only unsupported relationship of TAM was the effect of complexity on attitude. An academic contribution was that although some constructs of IDT did not show effect on the constructs of TAM, the model provided evidence of appropriated application of constructs of TAM with IDT to measure attitude and intention of use of Moodle. A management contribution was the understanding and prediction the teacher s behavior in relation to adoption and use process of Moodle, being possible to verify the effectiveness of innovative project of distance learning in the UFPB Virtual. / Nesse estudo, o modelo de pesquisa baseado no modelo de aceitação da tecnologia (Technology Acceptance Model - TAM) (DAVIS et al., 1989) e na teoria da difusão da inovação (Innovation Diffusion Theory - IDT) (ROGERS, 2003) foi usado para analisar a relação entre as características de inovação e o comportamento dos docentes no processo de adoção e de uso do Moodle em cursos de graduação a distância. Foi utilizada uma estratégia de levantamento (survey) aplicado a 162 docentes a distância da Universidade Federal da Paraíba Virtual, focando questão sobre as características percebidas de inovação, atitude e intenção em torno do uso do Moodle. Foram realizadas técnicas estatísticas multivariadas: 1) validação de translação para analisar a estrutura completa das escalas em relação à pertinência e representatividade dos itens e a verificação de que os itens propostos remetem ao construto em questão; 2) análise fatorial exploratória para conhecer a estrutura das inter-relações das variáveis originais da IDT; 3) análise fatorial confirmatória para garantir a validade conceitual para os padrões observados; 4) alpha de Cronbach para verificar a homogeneidade do conjunto de itens das escalas; 5) ANOVA para verificar as possíveis diferenças entre os grupos de respondentes; e 6) análise de regressão múltipla para analisar a relação entre os construtos. Os resultados revelaram que nem todos os fatores da IDT tiveram efeito sobre atitude e intenção. Apenas três construtos apresentaram efeito significativo sobre a atitude e/ou intenção: avanço relativo+compatibilidade por estilo de trabalho (β = 0,792), visibilidade (β = 0,166) e demonstrabilidade de resultado (β = 0,152). Além disso, os docentes tiveram uma atitude positiva em relação ao uso do Moodle bem como uma intenção positiva em relação ao seu uso futuro. Não foi possível confirmar todos os relacionamentos do TAM, provavelmente essa verificação foi comprometida por alguns problemas no processo de mensuração das escalas, sendo assim, o único relacionamento do TAM não suportado foi o efeito de complexidade sobre atitude. Uma contribuição acadêmica foi que apesar de alguns construtos da IDT não terem apresentado efeito sobre os construtos do TAM, o modelo forneceu evidência de aplicação apropriada dos construtos do TAM com os da IDT para medir a atitude e intenção de uso do Moodle. Uma contribuição gerencial foi a compreensão e previsão do comportamento dos docentes EaD em relação ao processo de adoção e uso do Moodle, possibilitando verificar a efetividade do projeto inovador de EaD na UFPB Virtual.
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Evaluation of HMA fracture mechanics-based thermal cracking model.Lin, Sen January 2011 (has links)
Low temperature cracking is an important form of asphalt pavement deterioration in cold regions. The cracks develop when thermally induced stresses exceed the fracture resistance of the asphalt pavement. In this study, by incorporating HMA fracture mechanics into thermal cracking model, a new integrated model is introduced to investigate low temperature cracking performance. To evaluate its reliability and accuracy, the predicted thermally induced stress and failure temperature are compared with the fracture stress and fracture temperature obtained from thermal stress restrained specimen test. The findings indicate that this HMA fracture mechanics-based thermal cracking model has a great potential to reliably evaluate the performance of asphalt mixtures subjected to thermally induced damage.
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Validation of Thermally Induced Internal Cracking in Asphalt Mixtures using Indirect Tensile TestOklu, Joshua 24 May 2022 (has links)
No description available.
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Amélioration des méthodes de calcul de cœurs de réacteurs nucléaires dans APOLLO3 : décomposition de domaine en théorie du transport pour des géométries 2D et 3D avec une accélération non linéaire par la diffusion / Contribution to the development of methods for nuclear reactor core calculations with APOLLO3 code : domain decomposition in transport theory for 2D and 3D geometries with nonlinear diffusion accelerationLenain, Roland 15 September 2015 (has links)
Ce travail de thèse est consacré à la mise en œuvre d’une méthode de décomposition de domaine appliquée à l’équation du transport. L’objectif de ce travail est l’accès à des solutions déterministes haute-fidélité permettant de correctement traiter les hétérogénéités des réacteurs nucléaires, pour des problèmes dont la taille varie d’un motif d’assemblage en 3 dimensions jusqu’à celle d’un grand cœur complet en 3D. L’algorithme novateur développé au cours de la thèse vise à optimiser l’utilisation du parallélisme et celle de la mémoire. La démarche adoptée a aussi pour but la diminution de l’influence de l’implémentation parallèle sur les performances. Ces objectifs répondent aux besoins du projet APOLLO3, développé au CEA et soutenu par EDF et AREVA, qui se doit d’être un code portable (pas d’optimisation sur une architecture particulière) permettant de réaliser des modélisations haute-fidélité (best estimate) avec des ressources allant des machines de bureau aux calculateurs disponibles dans les laboratoires d’études. L’algorithme que nous proposons est un algorithme de Jacobi Parallèle par Bloc Multigroupe. Chaque sous domaine est un problème multigroupe à sources fixes ayant des sources volumiques (fission) et surfaciques (données par les flux d’interface entre les sous domaines). Le problème multigroupe est résolu dans chaque sous domaine et une seule communication des flux d’interface est requise par itération de puissance. Le rayon spectral de l’algorithme de résolution est rendu comparable à celui de l’algorithme de résolution classique grâce à une méthode d’accélération non linéaire par la diffusion bien connue nommée Coarse Mesh Finite Difference. De cette manière une scalabilité idéale est atteignable lors de la parallélisation. L’organisation de la mémoire, tirant parti du parallélisme à mémoire partagée, permet d’optimiser les ressources en évitant les copies de données redondantes entre les sous domaines. Les architectures de calcul à mémoire distribuée sont rendues accessibles par un parallélisme hybride qui combine le parallélisme à mémoire partagée et à mémoire distribuée. Pour des problèmes de grande taille, ces architectures permettent d’accéder à un plus grand nombre de processeurs et à la quantité de mémoire nécessaire aux modélisations haute-fidélité. Ainsi, nous avons réalisé plusieurs exercices de modélisation afin de démontrer le potentiel de la réalisation : calcul de cœur et de motifs d’assemblages en 2D et 3D prenant en compte les contraintes de discrétisation spatiales et énergétiques attendues. / This thesis is devoted to the implementation of a domain decomposition method applied to the neutron transport equation. The objective of this work is to access high-fidelity deterministic solutions to properly handle heterogeneities located in nuclear reactor cores, for problems’ size ranging from colorsets of assemblies to large reactor cores configurations in 2D and 3D. The innovative algorithm developed during the thesis intends to optimize the use of parallelism and memory. The approach also aims to minimize the influence of the parallel implementation on the performances. These goals match the needs of APOLLO3 project, developed at CEA and supported by EDF and AREVA, which must be a portable code (no optimization on a specific architecture) in order to achieve best estimate modeling with resources ranging from personal computer to compute cluster available for engineers analyses. The proposed algorithm is a Parallel Multigroup-Block Jacobi one. Each subdomain is considered as a multi-group fixed-source problem with volume-sources (fission) and surface-sources (interface flux between the subdomains). The multi-group problem is solved in each subdomain and a single communication of the interface flux is required at each power iteration. The spectral radius of the resolution algorithm is made similar to the one of a classical resolution algorithm with a nonlinear diffusion acceleration method: the well-known Coarse Mesh Finite Difference. In this way an ideal scalability is achievable when the calculation is parallelized. The memory organization, taking advantage of shared memory parallelism, optimizes the resources by avoiding redundant copies of the data shared between the subdomains. Distributed memory architectures are made available by a hybrid parallel method that combines both paradigms of shared memory parallelism and distributed memory parallelism. For large problems, these architectures provide a greater number of processors and the amount of memory required for high-fidelity modeling. Thus, we have completed several modeling exercises to demonstrate the potential of the method: 2D full core calculation of a large pressurized water reactor and 3D colorsets of assemblies taking into account the constraints of space and energy discretization expected for high-fidelity modeling.
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Factors affecting computing students’ awareness of the latest ICTsAdegbehingbe, Oluwakemi D. January 2015 (has links)
Submitted in fulfillment of the requirements for the degree of Master of Technology: Information Technology, Durban University of Technology, Durban, South Africa, 2015. / Education is constantly challenged by rapid technological changes both in terms of curriculum renewal and in terms of students’ awareness of these new technologies. This is the reason why the aim of this study is to analyse factors affecting computing students’ awareness of the latest ICTs. This aim is further divided into four research sub-aims: the selection of the relevant theories for this research; the design of an appropriate conceptual model to support it; the empirical testing of the above mentioned model; and finally, recommendations arising from the research results. The first research sub-aim is accomplished through selection of the Innovation Diffusion Theory (IDT) as the theoretical framework of this study after a review of different theories of technology adoption. The second research sub-aim is accomplished through the design of a conceptual model which is an adaptation of the relationship between the prior conditions construct and the knowledge/awareness construct of IDT. The prior conditions that were studied are students’ perceived exposure to career guidance and students’ perceived curriculum currency. These prior conditions were analysed as possible predictors of computing students’ technology awareness. The third sub-aim is accomplished by means of a survey of 116 computing students from the four universities of the KwaZulu-Natal province of South Africa, the results of which validated most of the relationships hypothesized by the above mentioned model. Having knowledge/awareness as the main variable of the current study can be seen as its main contribution in view of the fact that only two studies from the reviewed literature on IDT are examining the awareness/knowledge construct. The fourth sub-aim is accomplished by means of some recommendations, one of which is that gender and ethnicity be considered when curriculating computing courses both at the high school level and at the university level.
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