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Now showing items 51-60 of 153
Buch
Gärten als Alltagskultur
(Universität Kassel, FB 6, ASL, Infosystem Planung, 2007)
Der Wunsch nach einem eigenen Garten scheint ungebrochen. Aktuelle Tendenzen in der Stadtentwicklung verlangen auch in diesem Bereich nach zeitgemäßen Ansätzen. Die Ausweisung von innerstädtischen Reihenhausgebieten ist nur eine Antwort darauf. Anhand unterschiedlicher Beispiele erstellt die vorliegende Tagungsdokumentation neu aufkommende Gartenformen abseits klassischer Konzepte vor. Drei Beiträge gehen außerdem der Frage nach, wie sich innovative Projekte aus dem frühen 20. Jahrhundert heute darstellen. Den ...
Dissertation
Künstliche Randbedingungen und Algebraische Äquivalenzen in der Elastizitätstheorie
(2007-07-18)
In dieser Arbeit werden zwei Aspekte bei Randwertproblemen der linearen Elastizitätstheorie untersucht: die Approximation von Lösungen auf unbeschränkten Gebieten und die Änderung von Symmetrieklassen unter speziellen Transformationen. Ausgangspunkt der Dissertation ist das von Specovius-Neugebauer und Nazarov in "Artificial boundary conditions for Petrovsky systems of second order in exterior domains and in other domains of conical type"(Math. Meth. Appl. Sci, 2004; 27) eingeführte Verfahren zur Untersuchung von ...
Preprint
The Navier-Stokes Equations with Particle Methods
(2007)
The non-stationary nonlinear Navier-Stokes equations describe the motion of a viscous incompressible fluid flow for 0<t≤T in some bounded three-dimensional domain.
Up to now it is not known wether these equations are well-posed or not. Therefore we use a particle method to develop a system of approximate equations. We show that this system can be solved uniquely and globally in time and that its solution has a high degree of spatial regularity. Moreover we prove that the system of approximate solutions has an ...
Preprint
Lagrangian approximations and weak solutions of the Navier-Stokes equations
(2007)
The motion of a viscous incompressible fluid flow in bounded domains with a smooth boundary can be described by the nonlinear Navier-Stokes equations. This description corresponds to the so-called Eulerian approach. We develop a new approximation method for the Navier-Stokes equations in both the stationary and the non-stationary case by a suitable coupling of the Eulerian and the Lagrangian representation of the flow, where the latter is defined by the trajectories of the particles of the fluid. The method leads to ...
Preprint
Computations in Relative Algebraic K-Groups
(2007)
Let G be finite group and K a number field or a p-adic field with ring of integers O_K. In the first part of the manuscript we present an algorithm that computes the relative algebraic K-group K_0(O_K[G],K) as an abstract abelian group. We solve the discrete logarithm problem, both in K_0(O_K[G],K) and the locally free class group cl(O_K[G]). All algorithms have been implemented in MAGMA for the case K = \IQ. In the second part of the manuscript we prove formulae for the torsion subgroup of K_0(\IZ[G],\IQ) for large ...
Preprint
Computing Generators of Free Modules over Orders in Group Algebras
(2007)
Let E be a number field and G be a finite group. Let A be any O_E-order of full rank in the group algebra E[G] and X be a (left) A-lattice. We give a necessary and sufficient condition for X to be free of given rank d over A. In the case that the Wedderburn decomposition E[G] \cong \oplus_xM_x is explicitly computable and each M_x is in fact a matrix ring over a field, this leads to an algorithm that either gives elements \alpha_1,...,\alpha_d \in X such that X = A\alpha_1 \oplus ... \oplusA\alpha_d or determines ...
Preprint
The Navier-Stokes Equations with Time Delay
(2007)
In the present paper we use a time delay epsilon > 0 for an energy conserving approximation of the nonlinear term of the non-stationary Navier-Stokes equations. We prove that the corresponding initial value problem (N_epsilon)in smoothly bounded domains G \subseteq R^3 is well-posed. Passing to the limit epsilon \rightarrow 0 we show that the sequence of stabilized solutions has an accumulation point such that it solves the Navier-Stokes problem (N_0) in a weak sense (Hopf).
Dissertation
Palestinian Non-Governmental Organisations caught between Reality and Challenges
(2007-09-10)
Non-governmental Organisations (NGOs) have not only gained more and more relevance in the development process of Near Eastern developing societies, but they have also raised an increasing scholarly interest. The traditional civil society in the Middle East, which used to be in charge of the tribe or large families, has been altered by new groups, which are organized around new social structures, interests and goals. The number of NGOs has experienced a swift increase in number and size, and the extent of some renders ...