Time filter

Source Type

Darmstadt, Germany

Braun M.,FH Darmstadt
Advances in Mathematics of Communications | Year: 2011

Network codes are sets of subspaces of a finite vectorspace over a finite field. Recently, this class of codes has found application in the error correction of message transmission within networks. Furthermore, binary codes can be represented as sets of subsets of a finite set. Hence, both kinds of codes can be regarded as substructures of lattices -in the first case it is the linear lattice and in the second case it is the power set lattice. This observation leads us to a more general investigation of similarities of both theories by means of lattice theory. In this paper we first examine general results of lattices in order to comprise basic considerations of network coding and binary vector coding theory. Afterwards we consider the issue of finding complements of subspaces. © 2011 AIMS-SDU. Source

May H.-O.,FH Darmstadt | Mausbach P.,Cologne University of Applied Sciences
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2012

The behavior of thermodynamic response functions and the thermodynamic scalar curvature in the supercritical region have been studied for a Lennard-Jones fluid based on a revised modified Benedict-Webb-Rubin equation of state. Response function extrema are sometimes used to estimate the Widom line, which is characterized by the maxima of the correlation lengths. We calculated the Widom line for the Lennard-Jones fluid without using any response function extrema. Since the volume of the correlation length is proportional to the Riemannian thermodynamic scalar curvature, the locus of the Widom line follows the slope of maximum curvature. We show that the slope of the Widom line follows the slope of the isobaric heat capacity maximum only in the close vicinity of the critical point and that, therefore, the use of response function extrema in this context is problematic. Furthermore, we constructed the vapor-liquid coexistence line for the Lennard-Jones fluid using the fact that the correlation length, and therefore the thermodynamic scalar curvature, must be equal in the two coexisting phases. We compared the resulting phase envelope with those from simulation data where multiple histogram reweighting was used and found striking agreement between the two methods. © 2012 American Physical Society. Source

Braun M.,FH Darmstadt
IEEE Transactions on Information Theory | Year: 2015

We visit generator matrices A0, A1, A2, ⋯ of all k-dimensional subspaces of the n-dimensional vector space over the field with two elements such that two consecutive matrices Ai and Ai+1 differ in exactly one bit. © 2014 IEEE. Source

Wolff K.E.,FH Darmstadt
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

In this paper we introduce the notion of a Temporal Relational Semantic System (TRSS) as a relational extension of a Temporal Conceptual Semantic System (TCSS) as defined by the author in 2007. TCSSs allow to represent states of distributed objects in concept lattices of specified views, the TRSSs enable the user to work in a conceptually simple way with arbitrary relational structures changing temporally. The flexible tools of conceptual scaling can now be applied also to relational structures. That yields for example a clear theoretical notion of the state of a temporal relation at some time granule. The main notions in TRSSs are visualized in some diagrams constructed from an example of a TRSS. © 2010 Springer-Verlag Berlin Heidelberg. Source

The invention is a device for influencing transfer of vibration between two units, one is mounted so that it can vibrate and the other is mounted to be quieted. A parallel circuit is connected indirectly or directly with both units, which comprises at least one elastically deformable element, with an associated first force path and at least one force generator, providing a second force path, oriented parallel to the first force path and associated with a lever, connected indirectly or directly with the one unit, which lever at one end is rotated about a first axis of rotation oriented orthogonally to both force paths.

Discover hidden collaborations