Publikationen


6718 Publikationen gefunden
    Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    M. Clausen, A. Dress, Johannes Grabmeier, M. Karpinski

    On zero-testing and interpolation of k-sparse multivariate polynomials over finite fields

    Theoretical Computer Science, vol. 84, no. 2, pp. 151-164

    DOI: 10.1016/0304-3975(91)90157-W

    Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    A. Dress, Johannes Grabmeier

    The Interpolation Problem for k-sparse Polynomials and Character Sums

    Advances in Applied Mathematics, vol. 12, no. 1, pp. 57-75

    Abstract anzeigen

    Motivated by a remarkable result of D. Y. Grigoriev and M. Karpinski, the interpolation problem for k-sparse multivariate polynomials has received some attention in recent years. In this note we want to show that essentially all of the results obtained so far hold more generally for k-sparse sums of characters of abelian monoids, thereby providing a useful unified approach to this active field of research. As it turns out, there are basically two different situations, in the first one reduction to the (rather trivial) case of cyclic monoids is possible, in the general case we can handle direct products of abelian monoids by using informations about the factors. Basic ingredients of these approaches are the construction of distinction sets for characters and zero-test sets for k-sparse character sums.

    Angewandte Wirtschaftswissenschaften

    Buch (Monographie)

    G. Dueck, Johannes Grabmeier, G. Jaeschke

    VLSI Complexity of Basic Arithmetic Operations

    Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    H. Gollan, Johannes Grabmeier

    Algorithms in Representation Theory and their Realization in the Computer Algebra

    Bayreuther Mathematische Schriften, no. 33, pp. 1-23

    Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    Johannes Grabmeier, A. Kerber

    The evaluation of irreducible polynomial representations of the general linerar groups and of the unitary groups over fields of characteristic 0

    Acta Applicandae Mathematicae, no. 8, pp. 271-291

    Abstract anzeigen

    We describe an efficient method for the computer evaluation of the ordinary irreducible polynomial representations of general linear groups using an integral form of the ordinary irreducible representations of symmetric groups. In order to do this, we first give an algebraic explanation of D. E. Littlewood's modification of I. Schur's construction. Then we derive a formula for the entries of the representing matrices which is much more concise and adapted to the effective use of computer calculations. Finally, we describe how one obtains — using this time an orthogonal form of the ordinary irreducible representations of symmetric groups — a version which yields a unitary representation when it is restricted to the unitary subgroup. In this way we adapt D. B. Hunter's results which heavily rely on Littlewood's methods, and boson polynomials come into the play so that we also meet the needs of applications to physics.

    Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    Johannes Grabmeier

    On the socle of Weyl modules

    Archiv der Mathematik, vol. 50, no. 4, pp. 319-322

    Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    Johannes Grabmeier

    Unzerlegbare Moduln mit trivialer Youngquelle und Darstellungstheorie der Schuralgebra

    Bayreuther Mathematische Schriften, no. 20, pp. 9-152

    Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    Johannes Grabmeier

    Kombinatorische Probleme aus der Darstellungstheorie der GLm(k)

    Publications de l'I.R.M.A., Seminaire Lotharingien de Combinatoire, no. 314/S-12, pp. 131-136

    Maschinenbau und Mechatronik

    Vortrag

    Markus Schinhärl

    Schneller und genauer - Optimale Polierstrategie durch variable Abtragsfunktion

    BayTech Optik Seminar, Deggendorf

    Angewandte Naturwissenschaften und WirtschaftsingenieurwesenHochschulleitung und -einrichtungenMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Christian Schopf, K. Fathima, Andreas Geiss, Markus Schinhärl, Christian Vogt, Rolf Rascher, Peter Sperber

    Ultraschallunterstütztes Schleifen von Linsen

    Siebtes Symposium - Zukunft Glas - von der Tradition zum High-Tech-Produkt

    Angewandte Naturwissenschaften und WirtschaftsingenieurwesenHochschulleitung und -einrichtungenMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    K. Fathima, Christian Schopf, Andreas Geiss, Markus Schinhärl, Christian Vogt, Rolf Rascher, Peter Sperber

    Precision finishing of aspherical optical components using ELID grinding

    Siebtes Symposium - Zukunft Glas - von der Tradition zum High-Tech-Produkt

    Angewandte Naturwissenschaften und WirtschaftsingenieurwesenElektrotechnik und MedientechnikHochschulleitung und -einrichtungenMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Markus Schinhärl, R. Stamp, Elmar Pitschke, Rolf Rascher, L. Smith, G. Smith, Andreas Geiss, Peter Sperber

    Advanced techniques for computer-controlled polishing

    Current Developments in Lens Design and Optical Engineering IX, vol. 7060, no. 70600Q ff.

    DOI: 10.1117/12.808036

    Abstract anzeigen

    Computer-controlled polishing has introduced determinism into the finishing of high-quality surfaces, for example those used as optical interfaces. Computer-controlled polishing may overcome many of the disadvantages of traditional polishing techniques. The polishing procedure is computed in terms of the surface error-profile and the material removal characteristic of the polishing tool, the influence function. Determinism and predictability not only enable more economical manufacture but also facilitate considerably increased processing accuracy. However, there are several disadvantages that serve to limit the capabilities of computer-controlled polishing, many of these are considered to be issues associated with determination of the influence function. Magnetorheological finishing has been investigated and various new techniques and approaches that dramatically enhance the potential as well as the economics of computer-controlled polishing have been developed and verified experimentally. Recent developments and advancements in computer-controlled polishing are discussed. The generic results of this research may be used in a wide variety of alternative applications in which controlled material removal is employed to achieve a desired surface specification, ranging from surface treatment processes in technical disciplines, to manipulation of biological surface textures in medical technologies.

    Angewandte Naturwissenschaften und WirtschaftsingenieurwesenHochschulleitung und -einrichtungenMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Markus Schinhärl, Christian Vogt, Andreas Geiss, R. Stamp, Peter Sperber, L. Smith, G. Smith, Rolf Rascher

    Forces acting between polishing tool and workpiece surface in magnetorheological finishing

    Proceedings of SPIE, Volume 7060, Current Developments in Lens Design and Optical Engineering IX (Optical Engineering + Applications, San Diego, CA, USA; August 10-14, 2008)

    DOI: 10.1117/12.794196

    Abstract anzeigen

    Magnetorheological finishing is a computer-controlled polishing technique that is used mainly in the field of high-quality optical lens production. The process is based on the use of a magnetorheological polishing fluid that is able, in a reversible manner, to change its viscosity from a liquid state to a solid state under the control of a magnetic field. This outstanding characteristic facilitates rapid control (in milliseconds) of the yield stress, and thus the pressure applied to the workpiece surface to be polished. A three-axis dynamometer was used to measure the forces acting between the magnetorheological fluid and the workpiece surface during determination of the material removal characteristic of the polishing tool (influence function). The results of a testing series using a QED Q22-X MRF polishing machine with a 50 mm wheel assembly show that the normal forces range from about 2 to 20 N. Knowledge of the forces is essential, especially when thin workpieces are to be polished and distortion becomes significant. This paper discusses, and gives examples of, the variation in the parameters experienced during a programme of experiments, and provides examples of the value of this work.

    Angewandte Naturwissenschaften und WirtschaftsingenieurwesenHochschulleitung und -einrichtungenMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Andreas Geiss, Rolf Rascher, J. Slabeycius, Markus Schinhärl, Peter Sperber, K. Fathima

    Material removal study at silicon nitride molds for the precision glass molding using MRF process

    Current Developments in Lens Design and Optical Engineering IX, vol. 7060, no. August

    DOI: 10.1117/12.794583

    Abstract anzeigen

    High-technology applications which are using high precision optic components in high and medium quantities have increased during recent years. One possibility to mass-produce e.g. such lenses is the precision glass molding (PGM) process. Especially for aspheric and free-form elements the PGM process has certain advantages. Premise is to manufacture accurate press molds, which have to feature smaller figure errors as the required lenses and may be made of materials, which are difficult to machine, like silicon nitride ceramics. These work pieces have to be machined in economical and steady process chains. However, due to the complex shapes and the corresponding accuracy an error dependent polishing is required. The Magnetorheological Finishing (MRF) as a high precision computer controlled polishing (CCP) technique is used and will further be presented in this work. To achieve the postulated demands a previous study of the material removal at selected machining parameters is needed. Changing machining parameters modify the removal, which is presented through values like the peak and volume removal rate. The value changes during the controlled variation of process parameters are described and discussed. Magnetorheological Finishing (MRF) provides one of the best methods to finish PGM molds that are relatively inaccurate to high precision in an economical, steady and efficient way. This work indicates the MRF removal selection and removal interference for the correction and finishing of precise silicon nitride molds for the precision glass molding.

    Maschinenbau und Mechatronik

    Zeitschriftenartikel

    Helmut Hansmaier

    Polymerbeton sorgt für Ruhe - Reduzierung der Vibrationsneigung lang auskragender Bohrstangen

    WB - Werkstatt + Betrieb, no. 11

    Maschinenbau und Mechatronik

    Zeitschriftenartikel

    Helmut Hansmaier

    Dynamische Eigenschaften im Visier - Untersuchungen an Vorrichtungskörpern aus Polymerbeton

    WB - Werkstatt + Betrieb, no. 9

    Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Vortrag

    Rolf Rascher

    Advanced technologies in precision optics manufacturing - a view to 2015?

    Maschinenbau und Mechatronik

    Vortrag

    Andreas Geiss

    Vom µm zu lamda/20 - MRF bei advanced materials

    BayTech Optik Seminar, Deggendorf

    Angewandte Naturwissenschaften und WirtschaftsingenieurwesenHochschulleitung und -einrichtungen

    Vortrag

    Rolf Rascher, Peter Sperber

    Blick in die Zukunft - Eine Agenda zur Optikfertigung 2015?

    BayTech Optik Seminar, Deggendorf

    Bauingenieurwesen und Umwelttechnik

    Beitrag (Sammelband oder Tagungsband)

    Hans Bulicek

    Vergleich der Anwendung interner Längsspannglieder ohne Verbund bzw. mit nachträglichem Verbund am Beispiel der Talbrücke Schallermühle

    Tagungsband zu den Innsbrucker Baufachtagen, 29. - 30.01.2009, Technische Universität Innsbruck