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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.
1

Moving or staying? : job mobility as a sorting process

Widerstedt, Barbro January 1998 (has links)
<p>Diss. (sammanfattning) Umeå : Umeå universitet, 1998</p> / digitalisering@umu
2

Novo procedimento para a realização de análise capwap no ensaio de carregamento dinâmico em estacas pré-moldadas. / New prodedure to perform CAPWAP analysis on dinamic load test in precast concrete piles.

Murakami, Daniel Kina 01 October 2015 (has links)
Desde a década de 1980 diversos autores apresentaram correlações entre provas de carga estática e ensaios de carregamento dinâmico em estacas. Para uma boa correlação é fundamental que os testes sejam bem executados e que atinjam a ruptura segundo algum critério, como o de Davisson, por exemplo, além de levar em conta o intervalo de tempo entre a execução da prova de carga estática e do ensaio dinâmico, face ao efeito \"set up\". Após a realização do ensaio dinâmico realiza-se a análise CAPWAP que permite a determinação da distribuição do atrito lateral em profundidade, a carga de ponta e outros parâmetros dos solos tais como quakes e damping. A análise CAPWAP é realizada por tentativas através do procedimento \"signal matching\", isto é, o melhor ajuste entre os sinais de força medido pelos sensores e o calculado. É relativamente fácil mostrar que a mesma solução pode ser obtida através de dados de entrada diferentes. Isso significa que apesar de apresentarem cargas mobilizadas próximas o formato da curva da simulação de prova de carga estática, obtida pelo CAPWAP, assim como a distribuição do atrito lateral, podem ser diferentes, mesmo que as análises apresentem \"match quality\" (MQWU) satisfatórios. Uma forma de corrigir o formato da curva simulada do CAPWAP, assim como a distribuição do atrito lateral, é através da comparação com provas de carga estática (PCE). A sobreposição das duas curvas, a simulada e a \"real\", permite a determinação do quake do fuste através do trecho inicial da curva carga-recalque da prova de carga estática, que por sua vez permite uma melhor definição da distribuição do atrito lateral e da reação de ponta. Neste contexto surge o conceito de \"match quality de recalques\" (MQR). Quando a PCE não está disponível, propõe-se efetuar um carregamento estático utilizando o peso próprio do martelo do bate-estaca (CEPM). Mostra-se, através de dois casos de obra, em que estavam disponíveis ensaios de carregamento dinâmico e PCEs, que esse procedimento permite obter uma melhor solução do ponto de vista físico, isto é consistente com as características do subsolo e com a curva carga-recalque da PCE, e não apenas matemático, através da avaliação do \"match quality\" (MQWU). / Since the 1980s a lot of authors showed correlations between static load tests and dynamic load tests on piles. For a good correlation it is necessary a good execution of the load test, also it is necessary to choose a capacity value from the results of the static load test, for example, the Davisson Offset limit load. The time of execution between the static load test and the dynamic load test should be considered because of the set up effect. Dynamic data may be further analyzed by CAPWAP Method to evaluate the soil resistance distribution, the toe resistance, quake and damping values. It is a signal matching method. Its results are based on the \"best possible match\" between computed pile top variable such as the pile top force and its measured equivalent. It is easy to demonstrate almost the same pile capacity on CAPWAP using different soil parameters. It means that even the pile capacity is almost the same, the shape of the pile top load-displacement of the CAPWAP Method and the shaft friction distribution can be different, although all results confirm good match quality. One way to correct the shape of the top loaddisplacement of the CAPWAP Method, as well as the shaft friction distribution, is by comparisson to a static load test. Overlaying both curves, the static load test and the CAPWAP Method, it is possible to determine the shaft quake value on the initial loads on the top load-displacement curve, allowing this way a improvement of the shaft resistance distribution and the toe resistance. In this context arises the concept of \"match quality of settlements\". When the static load test is not avaliabe, this thesis proposes a static load test using the hammer\'s weight of the pile driving machine. It is shown by two case studies that were available static load tests and dynamic load tests, this procedure allows a better solution on physics aspects, this is consistent with the subsoil conditions and the load-settlement curve of the static load test, not only a mathematical solution based on match quality.
3

Novo procedimento para a realização de análise capwap no ensaio de carregamento dinâmico em estacas pré-moldadas. / New prodedure to perform CAPWAP analysis on dinamic load test in precast concrete piles.

Daniel Kina Murakami 01 October 2015 (has links)
Desde a década de 1980 diversos autores apresentaram correlações entre provas de carga estática e ensaios de carregamento dinâmico em estacas. Para uma boa correlação é fundamental que os testes sejam bem executados e que atinjam a ruptura segundo algum critério, como o de Davisson, por exemplo, além de levar em conta o intervalo de tempo entre a execução da prova de carga estática e do ensaio dinâmico, face ao efeito \"set up\". Após a realização do ensaio dinâmico realiza-se a análise CAPWAP que permite a determinação da distribuição do atrito lateral em profundidade, a carga de ponta e outros parâmetros dos solos tais como quakes e damping. A análise CAPWAP é realizada por tentativas através do procedimento \"signal matching\", isto é, o melhor ajuste entre os sinais de força medido pelos sensores e o calculado. É relativamente fácil mostrar que a mesma solução pode ser obtida através de dados de entrada diferentes. Isso significa que apesar de apresentarem cargas mobilizadas próximas o formato da curva da simulação de prova de carga estática, obtida pelo CAPWAP, assim como a distribuição do atrito lateral, podem ser diferentes, mesmo que as análises apresentem \"match quality\" (MQWU) satisfatórios. Uma forma de corrigir o formato da curva simulada do CAPWAP, assim como a distribuição do atrito lateral, é através da comparação com provas de carga estática (PCE). A sobreposição das duas curvas, a simulada e a \"real\", permite a determinação do quake do fuste através do trecho inicial da curva carga-recalque da prova de carga estática, que por sua vez permite uma melhor definição da distribuição do atrito lateral e da reação de ponta. Neste contexto surge o conceito de \"match quality de recalques\" (MQR). Quando a PCE não está disponível, propõe-se efetuar um carregamento estático utilizando o peso próprio do martelo do bate-estaca (CEPM). Mostra-se, através de dois casos de obra, em que estavam disponíveis ensaios de carregamento dinâmico e PCEs, que esse procedimento permite obter uma melhor solução do ponto de vista físico, isto é consistente com as características do subsolo e com a curva carga-recalque da PCE, e não apenas matemático, através da avaliação do \"match quality\" (MQWU). / Since the 1980s a lot of authors showed correlations between static load tests and dynamic load tests on piles. For a good correlation it is necessary a good execution of the load test, also it is necessary to choose a capacity value from the results of the static load test, for example, the Davisson Offset limit load. The time of execution between the static load test and the dynamic load test should be considered because of the set up effect. Dynamic data may be further analyzed by CAPWAP Method to evaluate the soil resistance distribution, the toe resistance, quake and damping values. It is a signal matching method. Its results are based on the \"best possible match\" between computed pile top variable such as the pile top force and its measured equivalent. It is easy to demonstrate almost the same pile capacity on CAPWAP using different soil parameters. It means that even the pile capacity is almost the same, the shape of the pile top load-displacement of the CAPWAP Method and the shaft friction distribution can be different, although all results confirm good match quality. One way to correct the shape of the top loaddisplacement of the CAPWAP Method, as well as the shaft friction distribution, is by comparisson to a static load test. Overlaying both curves, the static load test and the CAPWAP Method, it is possible to determine the shaft quake value on the initial loads on the top load-displacement curve, allowing this way a improvement of the shaft resistance distribution and the toe resistance. In this context arises the concept of \"match quality of settlements\". When the static load test is not avaliabe, this thesis proposes a static load test using the hammer\'s weight of the pile driving machine. It is shown by two case studies that were available static load tests and dynamic load tests, this procedure allows a better solution on physics aspects, this is consistent with the subsoil conditions and the load-settlement curve of the static load test, not only a mathematical solution based on match quality.
4

An examination of the mentoring strategies and match quality indices that effect both a child’s change in social competency and a mentor’s sense of sufficiency

Collins, Sarah Margaret, 1977- 30 September 2010 (has links)
Much of the recent literature in mentoring centers on the effectiveness of volunteers who donate their time to relationships with children in need of a positive adult role model (DuBois & Karcher, 2005). Because mentors generally take on a great deal of responsibility with youth who are often at-risk either personally or academically (Commonwealth Fund, 1998; McLearn, Colasanto & Schoen, 1998; McLearn et al., 1999), researchers want to identify those variables and practices that increase the chance of a successful and beneficial relationship (Nakkula & Harris, 2005). This study examined the benefits of adult-child mentoring and looked for connections between the mentees’ growth in social competence and the relationship length, match quality, and specific mentoring strategies employed. The mentors’ perceptions of sufficiency about the match, the mentee’s additional resources, and their own abilities were also examined. A survey was distributed electronically to 890 Austin, Texas mentors about their relationships, and a separate school level survey was distributed to the 90 mentor contacts located in each school that utilizes mentors. School demographic data was also collected from the Texas Education Agency. The results indicate that longer and more high-quality matches, an increased importance placed on getting the mentee to care more about others, and spending more time with the mentee’s teachers all predict higher levels of growth in specific social competencies. The strength of the match was also a positive predictor of the mentors’ sense of sufficiency about themselves and about the impact of mentoring with their mentee. The results suggest a need for increased training in the specific caring and teacher-involvement mentor strategies, and for more discussion with mentors about the importance of committing to long-term, high-quality matches. / text
5

The phase-out of the nuclear family? : empirical studies on the economics and structure of modern Swedish families

Norberg-Schönfeldt, Magdalena January 2007 (has links)
<p>This thesis consists of three papers on the economics and structure of Swedish families.</p><p>Paper [I] examines the determinants of children’s educational achievement in Sweden. Special attention is given to the labour market work by mothers and fa-thers in terms of its influence on the educational outcome of their children, measured as grade point average (GPA) in compulsory as well as upper secon-dary school. The results show that there is a positive relationship between paren-tal income and GPA. Regarding the number of hours worked in the labour mar-ket, the results differ between mothers and fathers. Having a mother that works less than full time has positive effects on the child’s grades throughout the schooling of the child, whereas significant effects of the hours of work that the father puts in are found during upper secondary school only.</p><p>Paper [II] explores the role of financial surprises and match quality in the disso-lution of relationships. The analysis is carried out both for surprises in the short term earnings and surprises in the long-run earnings capacity. It is found that positive surprises in short term earnings have a destabilizing effect for a rela-tionship. Generally, a negative surprise in long-run earnings capacity for males has a destabilizing effect. However, if it is combined with a female positive sur-prise, the effect is stabilizing. Commitments become more stable the older the spouses are at the start, and if young children are present.</p><p>Paper [III] studies the role of unemployment in the dissolution of relationships by applying a two-step estimation method to an extensive data set, which con-tains information about young Swedish males and females. Unemployment is recognized as endogenous in the separation decision, and the results show that the effect of unemployment on separation is biased when unemployment is as-sumed to be exogenous in the separation equation. The probability of separation is found to be increasing with male unemployment, while female unemployment decreases the probability of dissolution.</p>
6

The phase-out of the nuclear family? : empirical studies on the economics and structure of modern Swedish families

Norberg-Schönfeldt, Magdalena January 2007 (has links)
This thesis consists of three papers on the economics and structure of Swedish families. Paper [I] examines the determinants of children’s educational achievement in Sweden. Special attention is given to the labour market work by mothers and fa-thers in terms of its influence on the educational outcome of their children, measured as grade point average (GPA) in compulsory as well as upper secon-dary school. The results show that there is a positive relationship between paren-tal income and GPA. Regarding the number of hours worked in the labour mar-ket, the results differ between mothers and fathers. Having a mother that works less than full time has positive effects on the child’s grades throughout the schooling of the child, whereas significant effects of the hours of work that the father puts in are found during upper secondary school only. Paper [II] explores the role of financial surprises and match quality in the disso-lution of relationships. The analysis is carried out both for surprises in the short term earnings and surprises in the long-run earnings capacity. It is found that positive surprises in short term earnings have a destabilizing effect for a rela-tionship. Generally, a negative surprise in long-run earnings capacity for males has a destabilizing effect. However, if it is combined with a female positive sur-prise, the effect is stabilizing. Commitments become more stable the older the spouses are at the start, and if young children are present. Paper [III] studies the role of unemployment in the dissolution of relationships by applying a two-step estimation method to an extensive data set, which con-tains information about young Swedish males and females. Unemployment is recognized as endogenous in the separation decision, and the results show that the effect of unemployment on separation is biased when unemployment is as-sumed to be exogenous in the separation equation. The probability of separation is found to be increasing with male unemployment, while female unemployment decreases the probability of dissolution.
7

A influência da qualidade do professor sobre a proficiência dos alunos: uma análise longitudinal

Marioni, Larissa da Silva 21 February 2014 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-02-12T10:34:36Z No. of bitstreams: 1 larissadasilvamarioni.pdf: 1596321 bytes, checksum: 14da9f2ee7d3c42e2dc4982065995603 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-02-26T12:07:08Z (GMT) No. of bitstreams: 1 larissadasilvamarioni.pdf: 1596321 bytes, checksum: 14da9f2ee7d3c42e2dc4982065995603 (MD5) / Made available in DSpace on 2016-02-26T12:07:08Z (GMT). No. of bitstreams: 1 larissadasilvamarioni.pdf: 1596321 bytes, checksum: 14da9f2ee7d3c42e2dc4982065995603 (MD5) Previous issue date: 2014-02-21 / Uma importante questão que vem recebendo a atenção de estudos na literatura de economia da educação se refere a identificação dos insumos relevantes para o aprendizado escolar das crianças e a possibilidade de implementação de políticas públicas que sejam efetivas. Em particular, os resultados de desempenho educacional decorrentes da qualidade do professor não são consensuais. Uma questão que ainda precisa ser melhor investigada é se um professor de boa qualidade afeta positivamente o desempenho escolar do aluno no decorrer do tempo. Nesse sentido, o objetivo do presente estudo é identificar o impacto das contribuições dos professores para o aprendizado através da proficiência dos alunos de escolas públicas e privadas em municípios selecionados do Brasil. A partir dos microdados longitudinais do projeto GERES - Geração Escolar, que acompanhou o desempenho dos alunos da primeira etapa do Ensino Fundamental nos anos de 2005 a 2008 utilizou-se a Função de Produção Educacional (FPE) incluindo os efeitos fixos de alunos, professores e o match entre eles para detectar o efeito da qualidade observada do professor e buscar evitar o viés decorrente da omissão de variáveis sobre o resultado dos alunos. A relevância do formato longitudinal dos dados possibilita avaliar a evolução do aprendizado das crianças e utilizar hipóteses menos restritivas na estimação dos resultados. Esse tipo de especificação, até onde foi investigado, não foi utilizado na literatura empírica do efeito do professor na proficiência dos alunos. A partir dos resultados foi verificado que com o controle dos efeitos fixos, inclusive do match, questões como o professor possuir outro trabalho tem impacto negativo na proficiência de seus alunos. As variáveis como educação, experiência e renda são significativas para português e os resultados são coerentes. Já para matemática, essas mesmas variáveis não são significativas, indicando que as características não observadas, quando controladas são capazes de explicar as diferenças nas notas. Através dos coeficientes das dummies dos professores o aluno que muda do pior para o melhor professor em português pode sair do primeiro nível de aprendizagem e atingir o terceiro de acordo com a escala do GERES. O aluno que muda do pior para o melhor professor em matemática pode sair do primeiro nível de aprendizagem e ir para o quinto nível de acordo com a escala para esta proficiência. / An important issue that has received attention in studies of the economics of education literature refers to identifying relevant inputs to children’s educational performance and the possibility of implementing public policies that are effective. In particular, the results of educational performance coming from teacher quality are not consensual. One issue that still needs to be investigated is whether a good quality teacher positively affects the academic performance of students over time. In this sense, the aim of this study is to identify the impact of teachers’ contributions to learning through the proficiency of students in public and private schools in selected municipalities in Brazil. From the longitudinal micro project GERES – Geração Escolar, which accompanied the students' performance in the first stage of elementary school in the years 2005 to 2008, we used the educational production function (EPF) including fixed effects for students, teachers and the match between them to detect the effect of the observed teacher’s quality and seek to avoid the bias caused by the omission of variables on the students’ outcomes. The relevance of longitudinal data allows to evaluate the evolution of children's learning and use less restrictive assumptions on the estimation results. This type of specification, as far as we investigated, was not used in the empirical literature of the teacher’s effect in student proficiency. From the results it was found that controlling for fixed effects, including the match, issues such as the teacher has other work has a negative impact on the proficiency of their students. Variables such as education, experience and income are significant for reading and the results are consistent. For math, these same variables are not significant, indicating that the unobserved characteristics when controlled are able to explain the differences in the notes. Using the coefficients of the dummies of the teachers, students that changes from worst to best teacher in portuguese can achieve the third level of learning according to the scale of GERES. A student who changes from worst to best math teacher can leave the first level of learning and achieve the fifth level in accordance with the scale for this proficiency.

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