Development of a new isogeometric finite element and its application for Lamb wave based structural health monitoring

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2012

Simulation gleitgelagerter Systeme in Mehrkörperprogrammen unter Berücksichtigung mechanischer und thermischer Deformationen

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2013

Elemente des Trainings sozialer Kompetenzen als ein Bestandteil der Hilfen zur Erziehung bzw. der sozialen Gruppenarbeit nach § 29 SGB VIII

[s.c.]

Simulation von gleit- und wälzgelagerten Systemen auf Basis eines Mehrkörpersystems für rotordynamische Anwendungen

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2013

Simulation von Wälzlagerschäden unter Berücksichtigung variabler Betriebsbedingungen

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2013

A Wireless Mesh Network NS-3 Simulation Model: Implementation and Performance Comparison With a Real Test-Bed

Wireless mesh networks present an attractive communication solution for various research and industrial projects. However, in many cases, the appropriate preliminary calculations which allow predicting the network behavior have to be made before the actual deployment. For such purposes, network simulation environments emulating the real network operation are often used. Within this paper, a behavior comparison of real wireless mesh network (based on 802.11s amendment) and the simulated one has been performed. The main objective of this work is to measure performance parameters of a real 802.11s wireless mesh network (average UDP throughput and average one-way delay) and compare the derived results with characteristics of a simulated wireless mesh network created with the NS-3 network simulation tool. Then, the results from both networks are compared and the corresponding conclusion is made. The corresponding results were derived from simulation model and real-worldtest-bed, showing that the behavior of both networks is similar. It confirms that the NS-3 simulation model is accurate and can be used in further research studies.

Higher order finite elements and the fictitious domain concept for wave propagation analysis

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2014

Factory Acceptance Test des Prozessleitsystems PCS 7 und Anlagenfeld Simulation mit WinMOD

Das Prozessleitsystem PCS 7 beinhaltet softwaretechnische Lösungen für alle Hierarchieebenen der industriellen Automatisierung von der Unternehmensleitebene bis zur Anlagenfeldebene. Mit der Simulationssoftware WinMOD können Komponenten,Signale und Prozesse einer Industrieanlage nachgebildet werden. Zudem bietet WinMOD Schnittstellenlösungen für gängige Speicherprogrammierbare Steuerungen und eignet sich somit für den Factory Acceptance Test (FAT) von Prozessleitsystemen. Die FATs sollen sich hauptsächlich auf die Überprüfung von Signaladressierungen und von Ursache und Wirkung konzentrieren. Im Rahmen der vorliegenden Arbeit wurden ausgewählte PCS 7–Projekte untersucht und auf deren Grundlage Aussagen getroffen wie zukünftig Simulationen effektiv erstellt werden können. Hierzu wurden mithilfe von WinMOD Simulationsmodule angelegt - welche reale Komponenten des Anlagenfeldes ersetzen – , ihr Aufbau beschrieben und in einer Bibliothek zusammengefasst. Im Anschluss wird auf die Verwendung der Bibliothek für verschiedene Anwendungsfälle eingegangen und eine Lösung präsentiert, welche das Erstellen einer Simulation für spezifische Projekte optimiert. Das Ergebnis zeigt auf, dass WinMOD sowohl neue Möglichkeiten der Durchführung für einen FAT liefert, wobei die Simulationserstellung nur einen geringen Mehraufwand bedeutet und sich die Durchführung der Simulation ergonomischer und kürzer gestaltet.

Simulation von Koexistenzszenarien für die Automation mit SEAMCAT an einem Anwendungsbeispiel

Diese Arbeit beschäftigt sich mit Koexistenzaussagen von Funktechnologien. Dafür wurden verschiedene Simulationstools auf ihre Eignung untersucht. Einen besonderen Schwerpunkt nimmt das Tool SEAMCAT ein. In der Arbeit wurde ein Modell ausgearbeitet, das für die Simulation mit SEAMCAT geeignet ist. Ergebnisse wurden mit Messungen verglichen, die das ifak Magdeburg für das System erstellt haben. Empfehlungen und Ausblicke für Funktechnologien in der Automation wurden abschließend benannt.

A comparative analysis of Cobb-Douglas model with additive and multiplicative error

This paper dis cusses the fitting of a Cobb-Doug las response curve Yi = αXβi, with additive error, Yi = αXβi + e i, instead of the usual multiplicative error Yi = αXβi (1 + e i). The estimation of the parameters A and B is discussed. An example is given with use of both types of error.

Sensitivity of simulation results to competing SAM updates

Recently there has been a renewed research interest in the properties of non survey updates of input-output tables and social accounting matrices (SAM). Along with the venerable and well known scaling RAS method, several alternative new procedures related to entropy minimization and other metrics have been suggested, tested and used in the literature. Whether these procedures will eventually substitute or merely complement the RAS approach is still an open question without a definite answer. The performance of many of the updating procedures has been tested using some kind of proximity or closeness measure to a reference input-output table or SAM. The first goal of this paper, in contrast, is the proposal of checking the operational performance of updating mechanisms by way of comparing the simulation results that ensue from adopting alternative databases for calibration of a reference applied general equilibrium model. The second goal is to introduce a new updatin! g procedure based on information retrieval principles. This new procedure is then compared as far as performance is concerned to two well-known updating approaches: RAS and cross-entropy. The rationale for the suggested cross validation is that the driving force for having more up to date databases is to be able to conduct more current, and hopefully more credible, policy analyses.

Voting by committees with exit

We study the problem of a society choosing a subset of new members from a finite set of candidates (as in Barberà, Sonnenschein, and Zhou, 1991). However, we explicitly consider the possibility that initial members of the society (founders) may want to leave it if they do not like the resulting new society. We show that, if founders have separable (or additive) preferences, the unique strategy-proof and stable social choice function satisfying voters' sovereignty (on the set of candidates) is the one where candidates are chosen unanimously and no founder leaves the society.

Infinite index subgroups and finiteness properties of intersections of geometrically finite groups

We explore which types of finiteness properties are possible for intersections of geometrically finite groups of isometries in negatively curved symmetric rank one spaces. Our main tool is a twist construction which takes as input a geometrically finite group containing a normal subgroup of infinite index with given finiteness properties and infinite Abelian quotient, and produces a pair of geometrically finite groups whose intersection is isomorphic to the normal subgroup.

Orthogonal systems in finite grahps

To a finite graph there corresponds a free partially commutative group: with the given graph as commutation graph. In this paper we construct an orthogonality theory for graphs and their corresponding free partially commutative groups. The theory developed here provides tools for the study of the structure of partially commutative groups, their universal theory and automorphism groups. In particular the theory is applied in this paper to the centraliser lattice of such groups.

Ab initio modeling and molecular dynamics simulation of the alpha 1b-adrenergic receptor activation.

This work describes the ab initio procedure employed to build an activation model for the alpha 1b-adrenergic receptor (alpha 1b-AR). The first version of the model was progressively modified and complicated by means of a many-step iterative procedure characterized by the employment of experimental validations of the model in each upgrading step. A combined simulated (molecular dynamics) and experimental mutagenesis approach was used to determine the structural and dynamic features characterizing the inactive and active states of alpha 1b-AR. The latest version of the model has been successfully challenged with respect to its ability to interpret and predict the functional properties of a large number of mutants. The iterative approach employed to describe alpha 1b-AR activation in terms of molecular structure and dynamics allows further complications of the model to allow prediction and interpretation of an ever-increasing number of experimental data.