University of Stuttgart

About: University of Stuttgart is a education organization based out in Stuttgart, Germany. It is known for research contribution in the topics: Laser & Finite element method. The organization has 27715 authors who have published 56370 publications receiving 1363382 citations. The organization is also known as: Universität Stuttgart.

Homogeneous catalysis by gold

Abstract: A comprehensive overview in the field of homogeneous catalysis by gold is given and the basic principles are discussed. It is also highlighted where homogeneous gold catalysts are already superior to other catalysts and where future possibilities for advantageous use of homogeneous gold catalysts exist.

Bounds for effective elastic moduli of disordered materials

Abstract: Recently P.H. Dederichs and R. Zeller (1973) have developed a formal theory of the bounds of odd order n for the effective elastic moduli of linearly elastic, disordered materials. The bounds are established by use of statistical information given in terms of correlation functions up to order n (= 1, 3, 5,…). This theory is extended to include the bounds of even order n. It is indicated how these bounds can be made optimum under the given statistical information. The results for bounds of even and odd order are obtained in forms which resemble Neumann series, containing multiple integrals up to order (n−1). These integrals can be calculated for certain materials which are classified in terms of a gradual statistical homogeneity, isotropy and disorder. Materials which possess these properties up to the correlation functions of nth order are called overall grade n materials. The optimum bounds for overall grade 2 and grade 3 materials are given explicitly. Optimum bounds for materials which are of grade ∞ in homogeneity and isotropy (i.e. (statistically) perfectly homogeneous and isotropic) and, at the same time, disordered of grade 2 or 3 are also derived. Those for grade 2 in disorder are the Z. Hashin and S. Shtrikman's (1963) bounds. Those for grade 3 are the narrowest, explicit bounds so far derived for random elastic materials. They contain within themselves the so-called self-consistent elastic moduli.

Time Limited Blackbox Security: Protecting Mobile Agents From Malicious Hosts

Abstract: In this paper, an approach to partially solve one of the most difficult aspects of security of mobile agents systems is presented, the problem of malicious hosts. This problem consists in the possibility of attacks against a mobile agent by the party that maintains an agent system node, a host. The idea to solve this problem is to create a blackbox out of an original agent. A blackbox is an agent that performs the same work as the original agent, but is of a different structure. This difference allows to assume a certain agent protection time interval, during which it is impossible for an attacker to discover relevant data or to manipulate the execution of the agent. After that time interval the agent and some associated data get invalid and the agent cannot migrate or interact anymore, which prevents the exploitation of attacks after the protection interval.