• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Efeito da inovação e difusão tecnológica sobre a mobilidade intersetorial de trabalhadores

Taveira, Juliana Gonçalves 10 February 2012 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-06-10T11:42:43Z No. of bitstreams: 1 julianagoncalvestaveira.pdf: 1804737 bytes, checksum: 4acd7844c33eb68437a0a59689439ae9 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T13:47:58Z (GMT) No. of bitstreams: 1 julianagoncalvestaveira.pdf: 1804737 bytes, checksum: 4acd7844c33eb68437a0a59689439ae9 (MD5) / Made available in DSpace on 2016-07-13T13:47:58Z (GMT). No. of bitstreams: 1 julianagoncalvestaveira.pdf: 1804737 bytes, checksum: 4acd7844c33eb68437a0a59689439ae9 (MD5) Previous issue date: 2012-02-10 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Essa dissertação se baseia na suposição teórica de que a distância tecnológica entre os setores reduz a propensão à mobilidade laboral intersetorial. Do ponto de vista empírico, o trabalho usa um painel com dados individuais da RAIS-Migra e dados setoriais da PINTEC e de insumo-produto, para os anos de 2003 a 2008. Estimaram-se modelos econométricos logit multinomial e logit multinomial com interceptos aleatórios, via GLLAMM (generalized linear latente and mixed models), para as subamostras de dados longitudinais de indivíduos qualificados e não qualificados e trabalhadores de setores intensivos e não intensivos em tecnologia. O método GLLAMM prescinde da suposição de independência das alternativas relevantes e, ao mesmo tempo, controla para as características não observáveis. A comparação dos resultados obtidos com os dois métodos mostra constância dos sinais dos coeficientes estimados, embora possam ser observadas variações em suas magnitudes e significâncias. Portanto, aponta-se para a necessidade do controle para as características individuais não observadas. Como principais resultados, destaca-se que a difusão tecnológica aumenta as chances de mudança de emprego em quase todos os tipos de mobilidade, para todas as subamostras. Em relação à inovação tecnológica, observam-se efeitos positivos e negativos na relação entre mobilidade e inovação. No primeiro caso, argumenta-se que a assimilação do conhecimento produzido externamente facilita tal mobilidade, enquanto que, no segundo caso, a inovação torna o conhecimento do trabalhador mais específico e, assim, aumenta a distância tecnológica entre os setores. Destaca-se ainda que as variáveis tecnológicas possuem maior importância para os trabalhadores qualificados do que para os não qualificados. Ademais, quando se analisa os setores não intensivos, uma nova tecnologia pode na verdade contribuir para a redução da distância entre os setores, assim, o impacto positivo da variável de inovação ocorre quando além de uma mudança de firma, há uma mudança de setor. / This thesis is based on the theoretical assumption that the technology distance among industries reduces the probability to intersectoral labor mobility. From the empirical point of view, this paper uses a labor market micro data from Brazilian Ministry of Labor - RAIS-Migra and manufacturing data from Technological Innovation Survey (PINTEC) and input-output tables, both stemming from Brazilian Statistical and Census Office (IBGE), for the years 2003 to 2008. We estimate the multinomial logit and the multinomial logit with random intercepts, via GLLAMM (generalized linear latent and mixed models), for four longitudinal data subsamples, such as skilled and unskilled workers and intensive and non-intensive technology manufacturing industries. The GLLAMM method is not based on the assumption of independence of the irrelevant alternative, and at the same time, it controls for unobservable characteristics. Using both methods, we reach robustness of the results, considering the signs of the estimated coefficients, even though there are differences in their significance and magnitude in some cases. As main results, we find that the technology diffusion increases the chances of a job change in almost all types of mobility for all subsamples. Focusing on technological innovation, there are positive and negative relationships between mobility and innovation. In the first case, it is argued that the assimilation of the knowledge externally produced increases the mobility. In the second case, the innovation makes the worker’s knowledge more specific and therefore increases the technological distance among the industries. It’s worth noticing that the technological variables are more important for skilled workers than for unskilled workers. Furthermore, when analyzing the non-intensive technology industries, a new technology can actually help to reduce the distance between the sectors, so the positive impact of innovation flow occurs when there is a change of both firm and industry.
2

Méthodes d'analyse statistique pour données répétées dans les essais cliniques : intérêts et applications au paludisme / Statistical method for analysis of recurrent events in clinical trials : interest and applications to malaria data

Sagara, Issaka 17 December 2014 (has links)
De nombreuses études cliniques ou interventions de lutte ont été faites ou sont en cours en Afrique pour la lutte contre le fléau du paludisme. En zone d'endémie, le paludisme est une maladie récurrente. La revue de littérature indique une application limitée des outils statistiques appropriés existants pour l'analyse des données récurrentes de paludisme. Nous avons mis en oeuvre des méthodes statistiques appropriées pour l'analyse des données répétées d'essais thérapeutiques de paludisme. Nous avons également étudié les mesures répétées d'hémoglobine lors du suivi de traitements antipaludiques en vue d'évaluer la tolérance ou sécurité des médicaments en regroupant les données de 13 essais cliniques.Pour l'analyse du nombre d'épisodes de paludisme, la régression binomiale négative a été mise en oeuvre. Pour modéliser la récurrence des épisodes de paludisme, quatre modèles ont été utilisés : i) Les équations d'estimation généralisées (GEE) utilisant la distribution de Poisson; et trois modèles qui sont une extension du modèle Cox: ii) le modèle de processus de comptage d'Andersen-Gill (AG-CP), iii) le modèle de processus de comptage de Prentice-Williams-Peterson (PWP-CP); et iv) le modèle de Fragilité partagée de distribution gamma. Pour l'analyse de sécurité, c'est-à-dire l'évaluation de l'impact de traitements antipaludiques sur le taux d'hémoglobine ou la survenue de l'anémie, les modèles linéaires et latents généralisés mixtes (« GLLAMM : generalized linear and latent mixed models ») ont été mis en oeuvre. Les perspectives sont l'élaboration de guides de bonnes pratiques de préparation et d'analyse ainsi que la création d'un entrepôt des données de paludisme. / Numerous clinical studies or control interventions were done or are ongoing in Africa for malaria control. For an efficient control of this disease, the strategies should be closer to the reality of the field and the data should be analyzed appropriately. In endemic areas, malaria is a recurrent disease. Repeated malaria episodes are common in African. However, the literature review indicates a limited application of appropriate statistical tools for the analysis of recurrent malaria data. We implemented appropriate statistical methods for the analysis of these data We have also studied the repeated measurements of hemoglobin during malaria treatments follow-up in order to assess the safety of the study drugs by pooling data from 13 clinical trials.For the analysis of the number of malaria episodes, the negative binomial regression has been implemented. To model the recurrence of malaria episodes, four models were used: i) the generalized estimating equations (GEE) using the Poisson distribution; and three models that are an extension of the Cox model: ii) Andersen-Gill counting process (AG-CP), iii) Prentice-Williams-Peterson counting process (PWP-CP); and (iv) the shared gamma frailty model. For the safety analysis, i.e. the assessment of the impact of malaria treatment on hemoglobin levels or the onset of anemia, the generalized linear and latent mixed models (GLLAMM) has been implemented. We have shown how to properly apply the existing statistical tools in the analysis of these data. The prospects of this work remain in the development of guides on good practices on the methodology of the preparation and analysis and storage network for malaria data.

Page generated in 0.0196 seconds