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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

Deltagande integrerar individ och organisation : En teoretisk studie i integrationens former, mekanismer och processer

Lindquist, Bert January 2011 (has links)
The aim of the present study is to clarify the nature of integration between the individual and the organization. I have utilized four analytical tools in this endeavor – forms of association, theoretical starting points, integrating factors, and principles of integration. The forms of association have been taken from Amitai Etzioni's model for describing the interplay between members' experience of an organization and organizational sanctions. These in turn provide us with three categories – coercion, when association is steered by constraint exercised by the organization; interest, when integration proceeds deliberately and voluntarily; and normative or institutional integration, when association is steered by a normative community. The starting point selected is important, and often decisive, for any effort to understand the connection between the individual and the organization. In the present effort to theoretically explain how a particular association between individual and organization emerges, I have deliberately selected human nature (the integrating unit) from the choice of two alternatives for the starting point. That is to say that the starting point for integration should be sought not in the organization, but in people. The reason for this decision is my contention that organizations have no organic form, and that they can be steered and influenced in a completely differently way than people. In order for the theoretical starting point to function as a explanatory factor, it should provide the location for an active element. I have chosen the individual's striving for development and maturity as the active element or integrating factor in this regard. The integration of individual and organization is fostered to the extent that the individual's striving for development is satisfied within the framework of the organization. I argue that participation is the principle of integration that serves this goal. In conclusion, participation promotes the integration of the individual and organization, and it drives the process of integration in respect to three forms of coordination – coercion, interest, and institutional integration. Submission (the absence of participation) leads to coercion. Negotiation (the preliminary stage of participation) leads to interest integration. Participation, finally, leads to institutional integration.
2

Intégrateurs exponentiels modifiés pour la simulation des vagues non linéaires / Non disponible

Eichwald, Brice 05 July 2013 (has links)
Pour réaliser des simulations précises aux temps longs pour des vagues non linéaires, il faut faire appel à des algorithmes d’évolution temporelle précis. En particulier, la combinaison d’un pas de temps adaptatif avec un facteur intégrant est connue pour être très efficace. Nous proposons une modification de cette technique. Le principe consiste à soustraire un certain polynôme à une EDP. Puis, comme pour le facteur intégrant, nous faisons un changement de variable pour retirer la partie linéaire. Mais nous espérons retirer quelque chose de plus afin de rendre l’EDP moins raide pour les calculs numériques. Le polynôme choisi est une expansion de Taylor autour du temps initial de la solution. Afin de calculer les différentes dérivées nécessaires, nous utilisons le Dense Output qui donne la possibilité d’approximer les dérivées de la solution à tout temps. Une fois le facteur intégrant modifié appliqué, nous faisons appel à une avance temporelle classique afin de résoudre l’équation d’évolution. Il a été considéré plusieurs schémas de Runge-Kutta avec pas de temps adaptatif. Nous avons tiré avantage des méthodes emboîtées, afin de ne pas calculer de nouvelles fonctions et perdre du temps de calcul, en utilisant uniquement des données déjà calculées durant l’évolution temporelle. Les résultats numériques montrent que l’efficacité de notre méthode varie selon les cas. Par exemple, nous avons vérifié que plus le profil de l’onde est pentue, plus notre méthode est efficace. Pour le modèle de vagues non linéaires le plus compliqué à notre disposition, le modèle HOS, nous avons pu réduire le nombre de pas de temps de calcul jusqu’à près de 30 % avec un schéma de Runge-Kutta de Dormand-Prince et jusqu’à plus de 99 % pour un schéma de Bogacki-Shampine. / Efficient time stepping algorithms are crucial for accurate long time simulations of nonlinear waves. In particular, adaptive time stepping combined with an integrating factor are known to be very effective. We propose a modification of the existing technique. The trick consists in subtracting a certain-order polynomial to a PDE. Then, like for the integrating factor, a change of variables is performed to remove the linear part. But, here, we hope to remove something more to make the PDE less stiff to numerical resolution. The polynomial is chosen as a Taylor expansion around the initial time of the solution. In order to calculate the different derivatives, we use a dense output which gives a possibility to approximate the derivatives of the solution at any time. The modified integrating factor being applied, a classical time-stepping method can be used to solve the remaining equation. We focus on various Runge-Kutta schemes with a varying step size. We take advantage of embedded methods and use an evolved adaptive step control. We do not need to calculate new functions and loose time of calculation only by using already estimated values during the temporal evolution. Numerical tests show that the actual efficiency of the method varies along cases. For example, we verified that steeper waves profiles give rise to better behaviour of the method. For fully nonlinear water wave simulations with the HOS model, we can save up to 30% of total time steps with a Dormand-Prince Runge-Kutta scheme and we can save up to 99% with the Bogacki-Shampine scheme.

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