Prof. Dr. S. Kobe
Professur für Theorie ungeordneter Festkörper

• Prof. Dr. S. Kobe
  

  Frau G. Schädlich (Sekretärin)

Teaching

• Brückenkurs Physik 2006

• Elektrodynamik WS 2005/2006

• Technische Neuroinformatik: Physikalische Grundlagen und Modelle
  Wintersemester 2007/2008
  Montags, 5. DS 14:50 Uhr, PHYS C213 (Beginn 22. Oktober)
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  Applet Neuronale Netze

• Themen für Diplomarbeiten (und andere Abschlußarbeiten):
  
  • Interessante Resultate mit einfachen Modellen der theoretischen Physik
  • Computersimulationen: "Rechnen, was zuvor noch nicht gerechnet und denken, was zuvor noch nicht gedacht"
  Konkret geht es hierbei um die Vorhersage der räumlichen Struktur von Proteinen aus der sogenannten Primärstruktur (d.h. der Sequenz der Aminosäuren; letztere werden durch die Buchstaben A R N D C Q E G H I L K M F P S T W Y V codiert, dabei steht A für Alanin, R für Arginin, ... V für Valin).

  Ein Beispiel:
  Primärstruktur für Epithermal Growth Factor (EGF), eines Liganden im Signalweg der Zellteilung:
  NSDSECPLSHDGYCLHDGVCMYIEALDKYACNCVVGYIGERCQYRDLKWWELR
  Berechnete räumliche Struktur mit Hilfe eines "coarse grained" Proteinmodells (tubes) im Vergleich mit dem experimentellen Resultat (sticks):
  

Research

• Spin glasses and neural networks
  (see publications)

• Dynamical Lattice Model (DLM) for Proteins (F. Dressel and S. Kobe)
  

Publications up to 1989 (selected papers)

• S. Kobe, K. Handrich
  Correlation function and misfit in a computer–simulated two–dimensional amorphous Ising antiferromagnet
  phys. stat. sol. (b) 73 (1976) K65–K67
  3 times cited
• S. Kobe
  Ground state of an Ising antiferromagnet with dense random packing structure
  in: Amorphous Magnetism II (R.A. Levy, R. Hasegawa, eds.), Plenum Press, New York and London, 1977, p. 529–534
• S. Kobe, A. Hartwig
  Exact ground state of finite amorphous Ising systems
  Comp. Phys. Commun. 16 (1978) 1–4
  9 times cited
• F. Daske, S. Kobe
  Field dependence of the ground state in finite amorphous Ising systems with frustration
  J. Magn. Magn. Mater 31–34 (1983) 1317–1318
  2 times cited
• A. Hartwig, F. Daske, S. Kobe
  A recursive branch–and–bound algorithm for the exact ground state of Ising spin-glass models
  Comp. Phys. Commun. 32 (1984) 133–138
  16 times cited
• S. Kobe, A. Schütte
  Ground state of neural network models
  Acta Phys. Polonica A75 (1989) 891–895

Publications 1990–2007

• S. Kobe, A.R. Ferchmin
  Liquid–quenched and sputtered alloys of 3d elements and main group elements
  in: Landolt–Börnstein, New Series, Group III, Vol. 19/h
  Springer-Verlag Berlin, Heidelberg, New York, London, Paris, Tokyo, Hong Kong, Barcelona, Budapest 1991 p. 1–207
• S. Roth, A.R. Ferchmin, S. Kobe
  Application–oriented amorphous ferromagnetic Alloys
  ibid., Vol. 19/i1, 1994, p. 144–192
• T. Klotz, S. Kobe
  "Valley structures" in the phase space of a finite 3D Ising spin glass with +–I interactions
  figures: 1 2 3 4 5 6 7
  J. Phys. A27 (1994) L95–100
  27 times cited
• T. Klotz, S. Kobe
  Exact low–energy landscape and relaxation phenomena in Ising spin glasses
  acta physica slovaca 44 (1994) 347–356
  7 times cited
• S. Kobe
  Persönliches: Ernst Ising zum 95. Geburtstag
  Physikalische Blätter 51 (1995) Nr. 5, 426
• S. Kobe, T. Klotz
  Frustration: How it can be measured
  Phys. Rev. E52 (1995) 5660–5663
  5 times cited
  Erratum: S. Kobe, cond–mat/0311657
• S. Kobe
  Ernst Ising — physicist and teacher
  Actas: Noveno Taller sur de Fisica del Solida, Misión Boroa 26 al 29 de Abril 1995, Universidad de la Frontera, Temuco, Chile, p. 01–02
  J. Stat. Phys. 88 (1997) 991–995
  2 times cited
  see also: Zh. Fiz. Dosl. (J. Phys. Studies) 2 (1998) 1–2 (in Ukrainian)

  Ernst Ising (May 10 1900 – May 11 1998), Photo: March 1996
  Bradley University Physics Department

• S. Kobe, T. Klotz
  Frustration: How it can be measured?
  Actas: Noveno Taller sur de Fisica del Solida, Misión Boroa 26 al 29 de Abril 1995, Universidad de la Frontera, Temuco, Chile, p. 49–53
  
• S. Kobe
  Exact low–energy landscape of Ising spin glass models
  ibid., p. 55–56
• J. Richter, S. Kobe, P. Ziesche
  Magnetische Festkörper mit Unordnung und Frustration — Modellsysteme für komplexe Erscheinungen in Natur und Technik
  Magdeburger Wissenschaftsjournal 1/96 (1996) 13–22
• T. Klotz, S. Kobe
  Cluster structure in the configuration space and relaxation in 3d +–I Ising spin–glass models
  Hayashibara Forum '95: Int. Symp. Coherent Approaches to Fluctuations, Kyoto, 1995
  World Scientific, Singapore, 1996, p. 192–195
• S. Kobe
  Application of combinatorial optimization to the problem of configuration space of Ising spin glasses
  Computer Simulation Studies in Condensed–Matter Physics IX, Proceedings of the Ninth Workshop, Athens, GA, USA, March 4–9 1996, (D.P Landau, K.K. Mon, H.–B. Schüttler, eds.), Springer Proceedings in Physics 82, Springer–Verlag Berlin Heidelberg, 1997, p. 178–181
• S. Kobe, E.E. Vogel
  Microscopic description of real and configuration spaces for +–J Ising lattices
  Actas X Simposio Chileno de Fisica, Valparaiso, Chile, Nov. 27–29, 1996, p. 129–130
• G. Milde, S. Kobe
  An exact learning algorithm for autoassociative neural networks with binary couplings
  J. Phys.A: Math. Gen., 30 (1997) 2349–2352
  3 times cited
• T. Klotz, S. Kobe
  Geometry of ground–state clusters in the configuration space of finite 3d +–J spin glasses
  J. Magn. Magn. Mater. 177–181 (1998) 1359–1360
• J.F. Valdés, J. Cartes, E.E. Vogel, S. Kobe, T. Klotz
  Relationship between the structure of the ground level and frustration in +–J Ising lattices
  Physica A 257 (1998) 557–562
• S. Kobe
  Das Ising–Modell — gestern und heute
  Physikalische Blätter 54 (1998) No. 10, 917–920
• E.E. Vogel, J. Cartes, P. Vargas, D. Altbir, S. Kobe, T. Klotz, M. Nogala
  Hysteresis in +–J Ising square lattices, figures 1a 1b 2 3
  Phys. Rev. B59 (1999) 3325–3328
• J. Klos, S. Kobe
  Simulated Annealing with Tsallis Weights for +–J Spin Glass
  Acta Physica Polonica A 97 (2000) 943–946
• S. Kobe
  Ernst Ising (1900 – 1998), figures 1 2 3 4 5 6 7
  Brazilian Journal of Physics 30 (2000) 649–653
• J. Klos, S. Kobe
  Generalized Simulated Annealing Algorithms Using Tsallis Statistics: Application to +–J Spin Glass Model
  in: Nonextensive Statistical Mechanics and Its Applications (S. Abe, Y. Okamo, eds.),
  Springer Series: Lecture Notes in Physics, Vol. 560, Springer Verlag Berlin Heidelberg (2001) 253–258
• J. Klos, S. Kobe
  Time decay of the remanent magnetization in +/– J spin glass model at T=0
  Phys. Rev. E 63 (2001) 066111–1 – 066111–4
• J. Klos, S. Kobe
  Simulated annealing with Tsallis weights for a system of interacting hard spheres
  J. Phys. A: Math. Gen. 35 (2002) 6261–6269
  Online at stack.iop.org/JPhysA/35/6261
  
• J. Krawczyk, S. Kobe
  Low–temperature dynamics of spin glasses: Walking in the energy landscape
  Physica A 315 (2002) 302–307
  1 times cited
• S. Kobe and J. Krawczyk
  Relationship between energy landscape and low–energy dynamics of +–J spin glasses
  J. Magn. Magn. Mater 272–276 (2004) 1284–1285
• S. Kobe
  Ground–state energy and frustration of the Sherrington–Kirkpatrick model and related models
  cond–mat/0311657
• S. Kobe and J. Krawczyk
  Ground states, energy landscape and low–temperature dynamics in +/–J spin glasses
  in: Computational Complexity and Statistical Physics,
  ed. A. Percus, G. Istrate, C. Moore,
  Oxford University Press, 2006, p. 141–155
• F. Dressel and S. Kobe
  Global optimization of proteins using a dynamical lattice model: Ground states and energy landscapes
  Chem. Phys. Letters 424 (2006) 369–373
• R. Schumann and S. Kobe
  Criticality conditions of the fully anisotropic Ising model with next–nearest neighbour interaction
  Physica A 386 (2007) 187–193
• F. Dressel and S. Kobe
  Exact Energy Landscapes of Proteins Using a Coarse–Grained Model
  in: Rugged Free Energy Landscapes (W. Janke, ed.),
  Springer Series: Lecture Notes in Physics, Vol. 736, Springer–Verlag Berlin Heidelberg (2008) 247–268
• M. Pelikan, H. G. Katzgraber, S. Kobe
  Finding Ground States of Sherrington-Kirkpatrick Spin Glasses with Hierarchical BOA and Genetic Algorithms
  MEDAL Report No. 2008004
  Genetic and Evolutionary Computation Conference (GECCO-2008), ACM Press, pp. 447–454

Recent Lectures

• S. Kobe
  Exact ground states of finite Ising spin glasses obtained by "branch–and–bound"
  Lecture, Universität Göttingen, June 16th, 2004

• S. Kobe
  Frustration and optimization:
  What magnetic materials and proteins have in common
  The Eight German–Vietnamese Seminar on Physics and Engineering,
  GVS8, Erlangen, April 3rd–9th, 2005,
  Book of Abstracts, ed. A. Pucci, D. T. Cat, A Winnacker, M. Batentschuk,
  Technische Fakultät Friedrich–Alexander–Universität Erlangen–Nürnberg, 2005, pp. 116–118
  (full lecture, April 7th, 2005)

• S. Kobe
  Optimierung und Frustration: Was magnetische Materialien und Proteine gemeinsam haben (2.5MByte)
  Vortrag, Theorie–Kolloquium, Fachgruppe Theoretische Physik,
  Martin-Luther-Universität Halle-Wittenberg, 4. Mai 2005

• S. Kobe and F. Dressel
  Optimization and frustration: The dynamical lattice model of proteins.
  Telluride Energy Landscapes Workshop, July 24th–August 5th, 2005,
  Lecture, Telluride, CO, USA, July 28th, 2005

• S. Kobe
  Ernst Ising — Physiker und Lehrer im 20. Jahrhundert
  Vortrag, Universität Augsburg, Augsburger Physikalisches Kolloquium, 21. November 2005
  (abstract)

• F. Dressel (with S. Kobe and M. Schroeder)
  Accurate prediction of protein structures — how to find the exact ground state
  8th International NTZ–Workshop on New Developments in Computational Physics CompPhys07,
  Institut für Theoretische Physik, Universität Leipzig, Germany
  29 Nov – 01 Dec 2007

Former co–workers

Dr. T. Klotz

Dissertation 1996
Zur Phasenraumstruktur in ungeordneten +/– Ising–Spinsystemen

S. Neef

Diplomarbeit 2001

Dr. J. Krawczyk

Dissertation 2003
Struktur der Energielandschaft und Relaxation von +–J Spinglas–Modellen

Dr. F. Dressel

Dissertation 2008
Sequenz, Energie, Struktur – Untersuchungen zur Beziehung zwischen Primär– und Tertiärstruktur in globulären und Membran-Proteinen

visits since Apr 10 2006