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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Assessment Of Second-order Analysis Methods Presented In Design Codes

Yildirim, Ufuk 01 April 2009 (has links) (PDF)
The main objective of the thesis is evaluating and comparing Second-Order Elastic Analysis Methods defined in two different specifications, AISC 2005 and TS648 (1980). There are many theoretical approaches that can provide exact solution for the problem. However, approximate methods are still needed for design purposes. Simple formulations for code applications were developed, and they are valid as acceptable results can be obtained within admissible error limits. Within the content of the thesis, firstly background information related to second-order effects will be presented. The emphasis will be on the definition of geometric non-linearity, also called as P-&amp / #948 / and P-&amp / #916 / effects. In addition, the approximate methods defined in AISC 2005 (B1 &ndash / B2 Method), and TS648 (1980) will be discussed in detail. Then, example problems will be solved for the demonstration of theoretical formulations for members with and without end translation cases. Also, the results obtained from the structural analysis software, SAP2000, will be compared with the results acquired from the exact and the approximate methods. Finally, conclusions related to the study will be stated.
132

Evidentiality And Second-order Social Cognition

Arslan, Burcu 01 January 2012 (has links) (PDF)
In this study, the development of a second-order false belief task is investigated by considering the impact of the acquisition of Turkish evidential markers, namely &ndash / DI (direct evidence) and &ndash / mIs (inference or hearsay). A neutral version of the tasks served as a control form. 21 kindergarten children (aged 4-5 years), 47 primary school children (aged 6- 12 years) and 10 adults participated in the study. Our results revealed that there is no effect of acquisition of evidentials on false belief understanding. Together with the other studies, there is a facilitative effect of &ndash / DI (direct evidence) in understanding of stories/narratives in general rather than false belief understanding for the children at the age of 4 to 6/7. In addition to the second-order false belief tasks (FBT_2), a simple working memory task (WST), a complex working memory task (LST), a perspective taking task (PTT) and a double- embedded relative clause task (REL_2) were used in order to investigate the developmental trend of these tasks and their possible relationship with second-order false belief understanding. Also, to the best of our knowledge this is the first time that a REL_2 task has been devised in a Turkish study. The general developmental trend was found for all tasks. Even if some significant correlations were found for FBT_2 score predicted from other tasks, analyses showed that only the contribution of age was significant. Since all of these domains are not related to second-order false belief reasoning but develop at the same time, it is not incompatible with the serial bottleneck hypothesis. In sum, the findings are matching with the modularity view that ToM is a faculty of the human mind at their own pace that does not share intrinsic content with other faculties such as language and working memory (Leslie et al., 2004). However, it develops together with those other faculties and they may constrain the expression of child
133

The birthing experience : towards an ecosystemic approach

Carpenter, Marisa 01 January 2002 (has links)
The birth of a child is a life-changing event in a woman's life. However, women's subjective experiences of giving birth have not been extensively researched, while the literature reflects an inherent realist approach. This has resulted in a decontextualised account of this critical event in women's lives. This conceptual study discusses the body of knowledge on the birthing experience from a widened perspective that includes not only the birthing woman, but also the people she interacts with and the context in which birth is embedded. The study comments on the way birth is managed in technological society and how its inherent Newtonian epistemology impacts on a woman's experience of birth. Ecosystemic epistemology is presented as an alternative approach which provides an holistic understanding of this experience. A reconceptualisation is proposed which acknowledges the social construction of birth. Lastly, the alternative birth movement as a more holistic approach to birth is discussed
134

Preliminary Design of Slender Reinforced Concrete Highway Bridge Pier Systems

Kuzmanovic, Aleksandar 26 June 2014 (has links)
Feasible span-to-depth ratios for many modern bridge systems have been identified and documented in literature. No such parameters have been adequately identified in terms of proportioning bridge piers. This thesis includes a study of 22 existing reinforced concrete highway bridges and their respective pier systems to determine the state-of-the-art in design. The effect of different geometric and material parameters such as concrete strength, reinforcement ratio and slenderness ratio on the structural behavior of individual piers and multiple pier systems was examined. Approximate methods, which may be used for the purposes of preliminary design are discussed and reviewed. Serviceability and ultimate limit states design aids that can be used to identify appropriate preliminary cross-sectional pier dimensions and reinforcement ratios for individual piers given various slenderness ratios were developed. The structural behavior as well as an approach to the preliminary design of multiple pier bridge systems is presented.
135

Preliminary Design of Slender Reinforced Concrete Highway Bridge Pier Systems

Kuzmanovic, Aleksandar 26 June 2014 (has links)
Feasible span-to-depth ratios for many modern bridge systems have been identified and documented in literature. No such parameters have been adequately identified in terms of proportioning bridge piers. This thesis includes a study of 22 existing reinforced concrete highway bridges and their respective pier systems to determine the state-of-the-art in design. The effect of different geometric and material parameters such as concrete strength, reinforcement ratio and slenderness ratio on the structural behavior of individual piers and multiple pier systems was examined. Approximate methods, which may be used for the purposes of preliminary design are discussed and reviewed. Serviceability and ultimate limit states design aids that can be used to identify appropriate preliminary cross-sectional pier dimensions and reinforcement ratios for individual piers given various slenderness ratios were developed. The structural behavior as well as an approach to the preliminary design of multiple pier bridge systems is presented.
136

Refined macroscopic traffic modelling via systems of conservation laws

Richardson, Ashlin D. 24 October 2012 (has links)
We elaborate upon the Herty-Illner macroscopic traffic models which include special non-local forces. The first chapter presents these in relation to the traffic models of Aw-Rascle and Zhang, arguing that non-local forces are necessary for a realistic description of traffic. The second chapter considers travelling wave solutions for the Herty-Illner macroscopic models. The travelling wave ansatz for the braking scenario reveals a curiously implicit nonlinear functional differential equation, the jam equation, whose unknown is, at least to conventional tools, inextricably self-argumentative! Observing that analytic solution methods fail for the jam equation yet succeed for equations with similar coefficients raises a challenging problem of pure and applied mathematical interest. An unjam equation analogous to the jam equation explored by Illner and McGregor is derived. The third chapter outlines refinements for the Herty-Illner models. Numerics allow exploration of the refined model dynamics in a variety of realistic traffic situations, leading to a discussion of the broadened applicability conferred by the refinements: ultimately the prediction of stop-and-go waves. The conclusion asserts that all of the above contribute knowledge pertinent to traffic control for reduced congestion and ameliorated vehicular flow. / Graduate
137

Oscillation Of Second Order Dynamic Equations On Time Scales

Kutahyalioglu, Aysen 01 August 2004 (has links) (PDF)
During the last decade, the use of time scales as a means of unifying and extending results about various types of dynamic equations has proven to be both prolific and fruitful. Many classical results from the theories of differential and difference equations have time scale analogues. In this thesis we derive new oscillation criteria for second order dynamic equations on time scales.
138

An exploratory study of the psychology of forgiveness: an interpersonal perspective

Kotzé, Hilda Norma 30 November 2006 (has links)
This qualitative study explores the meaning of interpersonal forgiveness, using a both/and or postmodern epistemology and a phenomenological methodology. Forgiveness is seen as a reframe that could transform a limiting, disempowering dominant narrative into a more empowering and useful story. The researcher interviews three participants to co-create stories of forgiveness. Themes of emotional discomfort; blame and responsibility; shift to empathy; forgiveness as process; and lasting change or forgiveness incorporated into way of life, are identified. / Psychology / M.A. (Clinical Psychology)
139

Sensitivity Analysis of Longitudinal Measurement Non-Invariance: A Second-Order Latent Growth Model Approach with Ordered-Categorical Indicators

January 2016 (has links)
abstract: Researchers who conduct longitudinal studies are inherently interested in studying individual and population changes over time (e.g., mathematics achievement, subjective well-being). To answer such research questions, models of change (e.g., growth models) make the assumption of longitudinal measurement invariance. In many applied situations, key constructs are measured by a collection of ordered-categorical indicators (e.g., Likert scale items). To evaluate longitudinal measurement invariance with ordered-categorical indicators, a set of hierarchical models can be sequentially tested and compared. If the statistical tests of measurement invariance fail to be supported for one of the models, it is useful to have a method with which to gauge the practical significance of the differences in measurement model parameters over time. Drawing on studies of latent growth models and second-order latent growth models with continuous indicators (e.g., Kim & Willson, 2014a; 2014b; Leite, 2007; Wirth, 2008), this study examined the performance of a potential sensitivity analysis to gauge the practical significance of violations of longitudinal measurement invariance for ordered-categorical indicators using second-order latent growth models. The change in the estimate of the second-order growth parameters following the addition of an incorrect level of measurement invariance constraints at the first-order level was used as an effect size for measurement non-invariance. This study investigated how sensitive the proposed sensitivity analysis was to different locations of non-invariance (i.e., non-invariance in the factor loadings, the thresholds, and the unique factor variances) given a sufficient sample size. This study also examined whether the sensitivity of the proposed sensitivity analysis depended on a number of other factors including the magnitude of non-invariance, the number of non-invariant indicators, the number of non-invariant occasions, and the number of response categories in the indicators. / Dissertation/Thesis / Doctoral Dissertation Psychology 2016
140

Avaliação da aplicação da análise de segunda ordem em pórticos de edifícios correntes em aço / Assessment of the application of second order analysis to current steel building frames

Pires Filho, Carlos Augusto Bonifácio 01 March 2011 (has links)
Made available in DSpace on 2015-03-26T13:28:04Z (GMT). No. of bitstreams: 1 texto completo.pdf: 6612372 bytes, checksum: b13d5987ee6587979e4a1d61f6ce7737 (MD5) Previous issue date: 2011-03-01 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / This work presents the assessment of the application of second-order analysis to currents steel structures. Aspects related to the structural analysis, structural stability and design, are discussed according to the requirements of ABNT NBR8800:1986 and ABNT NBR8800:2008. The first-order analysis and the effective length approach are compared with the second-order analysis considering the initial imperfections proposed by ABNT NBR8800:2008. The results of the second-order analysis performed with a computer program are compared with the results obtained with the Notional Load Approach (MAES), regarded in the Annex D of ABNT NBR8800:2008. Eight case studies are presented in order to compare the responses of the different types of analysis carried out and to compare the results of the ultimate load-carrying capacity of structural members according to the methodology proposed by ABNT NBR8800:1986 and ABNT NBR8800:2008. It was found out that the results obtained with MAES were very close to those obtained with an approximated second-order analysis (ASO) performed with SAP2000. Moreover, it was noted a close proximity between the results of normal force, shear force and bending moment for the different types of analysis performed (APO, ASO and ASO-MAES), confirming the hypothesis that to "non-sway" frames the influence of second-order effects is not relevant. Regarding the ultimate load-carrying capacity verification of columns, it was found that the ABNT NBR8800:2008 interaction equation led, systematically, to a more economical design. On the other hand, the ABNT NBR8800:1986 approach, using the effective length concept, was always conservative. / Neste trabalho apresenta-se uma avaliação da aplicabilidade da análise de segunda ordem a estruturas de aço correntes. Aspectos relacionados à análise estrutural, à estabilidade estrutural e ao dimensionamento, são discutidos segundo as prescrições da ABNT NBR8800:1986 e da ABNT NBR8800:2008. A análise de primeira ordem e o método do coeficiente de flambagem (K) são avaliados e confrontados com a análise de segunda ordem e a consideração das imperfeições iniciais proposto pela ABNT NBR8800:2008. Os resultados das análises realizadas de acordo com as normas citadas anteriormente, obtidos com auxílio de um programa computacional, são comparados com os resultados obtidos por meio da aplicação do Método de Amplificação dos Esforços Solicitantes (MAES), previsto no Anexo D da ABNT NBR8800:2008. São apresentados oito estudos de caso com o intuito de comparar as respostas dos diferentes tipos de análise e comparar os resultados da verificação da capacidade última de elementos estruturais, segundo a metodologia proposta pela ABNT NBR8800:1986 e pela ABNT NBR8800:2008. Os resultados obtidos por meio do MAES foram muito próximos daqueles obtidos por meio da análise de segunda ordem aproximada (ASO), realizada com auxílio do programa computacional SAP 2000. Notou-se uma grande proximidade entre os resultados de esforços normal, cortante e momento fletor para os diferentes tipos de análise realizados (APO, ASO e ASO-MAES), confirmando a premissa de que em estruturas de pequena deslocabilidade a influência dos efeitos de segunda ordem não é relevante, ou seja, não há um aumento considerável dos esforços internos solicitantes. Com relação às verificações da capacidade última dos pilares, observou-se que a metodologia da ABNT NBR8800:2008 conduziu, sistematicamente, a um dimensionamento mais econômico. Por outro lado, a metodologia prevista na ABNT NBR8800:1986, que utiliza o conceito do comprimento efetivo de flambagem, mostrou-se sempre a favor da segurança.

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