Publications | Max Planck Institute for Intelligent Systems

2008

mms Smith, T. H. R., Vasilyev, O., Abraham, D. B., Maciolek, A., Schmidt, M. Interfaces in confined Ising models: Kawasaki, Glauber and sheared dynamics {Journal of Physics: Condensed Matter}, 20(49), 2008 (article)

Critical fields of an exchange coupled two-layer composite particle

Goll, D., Kronmüller, H.

{Physica B}, 403, pages: 1854-1859, 2008 (article)

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mms Goll, D., Kronmüller, H. Critical fields of an exchange coupled two-layer composite particle {Physica B}, 403, pages: 1854-1859, 2008 (article)

Coercivity and domain structure of nanograined Fe-C alloys after high-pressure torsion

Protasova, S. G., Straumal, B., Dobatkin, S. V., Goll, D., Schütz, G., Baretzky, B., Mazilkin, A. A., Nebrasov, A. N.

{Journal of Materials Science}, 43, pages: 3775-3781, 2008 (article)

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mms Protasova, S. G., Straumal, B., Dobatkin, S. V., Goll, D., Schütz, G., Baretzky, B., Mazilkin, A. A., Nebrasov, A. N. Coercivity and domain structure of nanograined Fe-C alloys after high-pressure torsion {Journal of Materials Science}, 43, pages: 3775-3781, 2008 (article)

Near-surface compositional oscillations of Co diffused into Si(100) at -60\mbox^∘C: a study by high-resolution Rutherford backscattering

Dash, S. P., Goll, D., Carstanjen, H. D.

{Applied Physics A}, 91, pages: 379-383, 2008 (article)

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mms Dash, S. P., Goll, D., Carstanjen, H. D. Near-surface compositional oscillations of Co diffused into Si(100) at -60\mbox^∘C: a study by high-resolution Rutherford backscattering {Applied Physics A}, 91, pages: 379-383, 2008 (article)

Epitaxial growth and properties of (001)-oriented TbBaCo2O6-αfilms

Kasper, N. V., Wochner, P., Vigliante, A., Dosch, H., Jakob, G., Carstanjen, H. D., Kremer, R. K.

{Journal of Applied Physics}, 103, 2008 (article)

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mms Kasper, N. V., Wochner, P., Vigliante, A., Dosch, H., Jakob, G., Carstanjen, H. D., Kremer, R. K. Epitaxial growth and properties of (001)-oriented TbBaCo2O6-αfilms {Journal of Applied Physics}, 103, 2008 (article)

Magnetic properties of exchange-coupled L10-FePt/Fe composite elements

Goll, D., Breitling, A., Macke, S.

{IEEE Transactions on Magnetics}, 44(11):3472-3475, 2008 (article)

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mms Goll, D., Breitling, A., Macke, S. Magnetic properties of exchange-coupled L10-FePt/Fe composite elements {IEEE Transactions on Magnetics}, 44(11):3472-3475, 2008 (article)

Colloidal cobalt-doped ZnO nanorods: synthesis, structural, and magnetic properties

Büsgen, T., Hilgendorff, M., Irsen, S., Wilhelm, F., Rogalev, A., Goll, D., Giersig, M.

{Journal of Physical Chemistry C}, 112(7):2412-2417, 2008 (article)

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mms Büsgen, T., Hilgendorff, M., Irsen, S., Wilhelm, F., Rogalev, A., Goll, D., Giersig, M. Colloidal cobalt-doped ZnO nanorods: synthesis, structural, and magnetic properties {Journal of Physical Chemistry C}, 112(7):2412-2417, 2008 (article)

Raman studies of hydrogen adsorbed on nanostructured porous materials

Panella, B., Hirscher, M.

{Physical Chemistry Chemical Physics}, 10, pages: 2910-2917, 2008 (article)

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mms Panella, B., Hirscher, M. Raman studies of hydrogen adsorbed on nanostructured porous materials {Physical Chemistry Chemical Physics}, 10, pages: 2910-2917, 2008 (article)

Thermal evolution and grain boundary phase transformations in severely deformed nanograined Al-Zn alloys

Straumal, B., Valiev, R., Kogtenkova, O., Zieba, P., Czeppe, T., Bielanska, E., Faryna, M.

{Acta Materialia}, 56(20):6123-6131, 2008 (article)

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mms Straumal, B., Valiev, R., Kogtenkova, O., Zieba, P., Czeppe, T., Bielanska, E., Faryna, M. Thermal evolution and grain boundary phase transformations in severely deformed nanograined Al-Zn alloys {Acta Materialia}, 56(20):6123-6131, 2008 (article)

Hydrogen storage properties of Pd nanoparticle/carbon template composites

Campesi, R., Cuevas, F., Gadiou, R., Leroy, E., Hirscher, M., Vix-Guterl, C., Latroche, M.

{Carbon}, 46, pages: 206-214, 2008 (article)

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mms Campesi, R., Cuevas, F., Gadiou, R., Leroy, E., Hirscher, M., Vix-Guterl, C., Latroche, M. Hydrogen storage properties of Pd nanoparticle/carbon template composites {Carbon}, 46, pages: 206-214, 2008 (article)

Reversible transformation of a grain-boundary facet into a rough-to-rough ridge in zinc

Straumal, B. B., Gornakova, A. S., Sursaeva, V. G.

{Philosophical Magazine Letters}, 88(1):27-36, 2008 (article)

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mms Straumal, B. B., Gornakova, A. S., Sursaeva, V. G. Reversible transformation of a grain-boundary facet into a rough-to-rough ridge in zinc {Philosophical Magazine Letters}, 88(1):27-36, 2008 (article)

A library for locally weighted projection regression

Klanke, S., Vijayakumar, S., Schaal, S.

Journal of Machine Learning Research, 9, pages: 623-626, 2008, clmc (article)

Abstract

In this paper we introduce an improved implementation of locally weighted projection regression (LWPR), a supervised learning algorithm that is capable of handling high-dimensional input data. As the key features, our code supports multi-threading, is available for multiple platforms, and provides wrappers for several programming languages.

link (url) [BibTex]

am Klanke, S., Vijayakumar, S., Schaal, S. A library for locally weighted projection regression Journal of Machine Learning Research, 9, pages: 623-626, 2008, clmc (article)

link (url) [BibTex]

Preface to the Journal of Micro-Nano Mechatronics

Dario, P., Fukuda, T., Sitti, M.

Journal of Micro-Nano Mechatronics, 4(1-2):1-1, Springer-Verlag, 2008 (article)

pi Dario, P., Fukuda, T., Sitti, M. Preface to the Journal of Micro-Nano Mechatronics Journal of Micro-Nano Mechatronics, 4(1-2):1-1, Springer-Verlag, 2008 (article)

A legged anchoring mechanism for capsule endoscopes using micropatterned adhesives

Glass, P., Cheung, E., Sitti, M.

IEEE Transactions on Biomedical Engineering, 55(12):2759-2767, IEEE, 2008 (article)

Project Page [BibTex]

pi Glass, P., Cheung, E., Sitti, M. A legged anchoring mechanism for capsule endoscopes using micropatterned adhesives IEEE Transactions on Biomedical Engineering, 55(12):2759-2767, IEEE, 2008 (article)

Project Page [BibTex]

The hole is important! The quest for ferromagnetism in doped ZnO

Tietze, T., Gacic, M., Schütz, G., Jakob, G., Brück, S., Goering, E.

{BESSY Highlights 2007}, pages: 14-15, 2008 (article)

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mms Tietze, T., Gacic, M., Schütz, G., Jakob, G., Brück, S., Goering, E. The hole is important! The quest for ferromagnetism in doped ZnO {BESSY Highlights 2007}, pages: 14-15, 2008 (article)

Limitations of a simple quantum mechanical model: Magnetic dichroism in a relativistic one-electron atom

Rodr\’\iguez, J. C., Kostoglou, C., Singer, R., Seib, J., Fähnle, M.

{Physica Status Solidi (B)}, 245(4):735-739, 2008 (article)

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mms Rodr\’\iguez, J. C., Kostoglou, C., Singer, R., Seib, J., Fähnle, M. Limitations of a simple quantum mechanical model: Magnetic dichroism in a relativistic one-electron atom {Physica Status Solidi (B)}, 245(4):735-739, 2008 (article)

Impact of irradiation-induced point defects on electronically and ionically induced magnetic relaxation mechanisms in titano-magnetites

Walz, F., Brabers, V. A. M., Kronmüller, H.

{Physica Status Solidi (A)}, 205(12):2934-2942, 2008 (article)

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mms Walz, F., Brabers, V. A. M., Kronmüller, H. Impact of irradiation-induced point defects on electronically and ionically induced magnetic relaxation mechanisms in titano-magnetites {Physica Status Solidi (A)}, 205(12):2934-2942, 2008 (article)

Polarization selective magnetic vortex dynamics and core reversal in rotating magnetic fields

Curcic, M., van Waeyenberge, B., Vansteenkiste, A., Weigand, M., Sackmann, V., Stoll, H., Fähnle, M., Tyliszczak, T., Woltersdorf, G., Back, C. H., Schütz, G.

{Physical Review Letters}, 101, 2008 (article)

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mms Curcic, M., van Waeyenberge, B., Vansteenkiste, A., Weigand, M., Sackmann, V., Stoll, H., Fähnle, M., Tyliszczak, T., Woltersdorf, G., Back, C. H., Schütz, G. Polarization selective magnetic vortex dynamics and core reversal in rotating magnetic fields {Physical Review Letters}, 101, 2008 (article)

X-ray spectroscopic investigations of Zn0.94Co0.06O thin films

Mayer, G., Fonin, M., Voss, S., Rüdiger, U., Goering, E.

{IEEE Transactions on Magnetics}, 44(11):2700-2703, 2008 (article)

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mms Mayer, G., Fonin, M., Voss, S., Rüdiger, U., Goering, E. X-ray spectroscopic investigations of Zn0.94Co0.06O thin films {IEEE Transactions on Magnetics}, 44(11):2700-2703, 2008 (article)

Experimental realization of graded L10-FePt/Fe composite media with perpendicular magnetization

Goll, D., Breitling, A., Gu, L., van Aken, P. A., Sigle, W.

{Journal of Applied Physics}, 104, 2008 (article)

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mms Goll, D., Breitling, A., Gu, L., van Aken, P. A., Sigle, W. Experimental realization of graded L10-FePt/Fe composite media with perpendicular magnetization {Journal of Applied Physics}, 104, 2008 (article)

Hard magnetic L10 FePt thin films and nanopatterns

Breitling, A., Goll, D.

{Journal of Magnetism and Magnetic Materials}, 320, pages: 1449-1456, 2008 (article)

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mms Breitling, A., Goll, D. Hard magnetic L10 FePt thin films and nanopatterns {Journal of Magnetism and Magnetic Materials}, 320, pages: 1449-1456, 2008 (article)

Spin-reorientation transition in Co/Pt multilayers on nanospheres

Eimüller, T., Ulbrich, T. C., Amaladass, E., Guhr, I. L., Tyliszczak, T., Albrecht, M.

{Physical Review B}, 77, 2008 (article)

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mms Eimüller, T., Ulbrich, T. C., Amaladass, E., Guhr, I. L., Tyliszczak, T., Albrecht, M. Spin-reorientation transition in Co/Pt multilayers on nanospheres {Physical Review B}, 77, 2008 (article)

Non-destructive compositional analysis of historic organ reed pipes

Manescu, A., Fiori, F., Giuliani, A., Kardjilov, N., Kasztovszky, Z., Rustichelli, F., Straumal, B.

{Journal of Physics: Condensed Matter}, 20, 2008 (article)

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mms Manescu, A., Fiori, F., Giuliani, A., Kardjilov, N., Kasztovszky, Z., Rustichelli, F., Straumal, B. Non-destructive compositional analysis of historic organ reed pipes {Journal of Physics: Condensed Matter}, 20, 2008 (article)

An advanced magnetic reflectometer

Brück, S., Bauknecht, S., Ludescher, B., Goering, E., Schütz, G.

{Review of Scientific Instruments}, 79, 2008 (article)

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mms Brück, S., Bauknecht, S., Ludescher, B., Goering, E., Schütz, G. An advanced magnetic reflectometer {Review of Scientific Instruments}, 79, 2008 (article)

Optimization strategies in human reinforcement learning

Hoffmann, H., Theodorou, E., Schaal, S.

Advances in Computational Motor Control VII, Symposium at the Society for Neuroscience Meeting, Washington DC, 2008, 2008, clmc (article)

PDF [BibTex]

am Hoffmann, H., Theodorou, E., Schaal, S. Optimization strategies in human reinforcement learning Advances in Computational Motor Control VII, Symposium at the Society for Neuroscience Meeting, Washington DC, 2008, 2008, clmc (article)

PDF [BibTex]

Dynamic modeling of stick slip motion in an untethered magnetic microrobot

Pawashe, C., Floyd, S., Sitti, M.

Proceedings of Robotics: Science and Systems IV, Zurich, Switzerland, 2008 (article)

pi Pawashe, C., Floyd, S., Sitti, M. Dynamic modeling of stick slip motion in an untethered magnetic microrobot Proceedings of Robotics: Science and Systems IV, Zurich, Switzerland, 2008 (article)

Frequency analysis with coupled nonlinear oscillators

Buchli, J., Righetti, L., Ijspeert, A.

Physica D: Nonlinear Phenomena, 237(13):1705-1718, August 2008 (article)

Abstract

We present a method to obtain the frequency spectrum of a signal with a nonlinear dynamical system. The dynamical system is composed of a pool of adaptive frequency oscillators with negative mean-field coupling. For the frequency analysis, the synchronization and adaptation properties of the component oscillators are exploited. The frequency spectrum of the signal is reflected in the statistics of the intrinsic frequencies of the oscillators. The frequency analysis is completely embedded in the dynamics of the system. Thus, no pre-processing or additional parameters, such as time windows, are needed. Representative results of the numerical integration of the system are presented. It is shown, that the oscillators tune to the correct frequencies for both discrete and continuous spectra. Due to its dynamic nature the system is also capable to track non-stationary spectra. Further, we show that the system can be modeled in a probabilistic manner by means of a nonlinear Fokker–Planck equation. The probabilistic treatment is in good agreement with the numerical results, and provides a useful tool to understand the underlying mechanisms leading to convergence.

link (url) DOI [BibTex]

mg Buchli, J., Righetti, L., Ijspeert, A. Frequency analysis with coupled nonlinear oscillators Physica D: Nonlinear Phenomena, 237(13):1705-1718, August 2008 (article)

link (url) DOI [BibTex]

In situ observation of cracks in gold nano-interconnects on flexible substrates

Olliges, S., Gruber, P. A., Orso, S., Auzelyte, V., Ekinci, Y., Solak, H. H., Spolenak, R.

{Scripta Materialia}, 58(3):175-178, 2008 (article)

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mms Olliges, S., Gruber, P. A., Orso, S., Auzelyte, V., Ekinci, Y., Solak, H. H., Spolenak, R. In situ observation of cracks in gold nano-interconnects on flexible substrates {Scripta Materialia}, 58(3):175-178, 2008 (article)

Transmission electron microscopy study of the intermixing of Fe-Pt multilayers

Kaiser, T., Sigle, W., Goll, D., Goo, N. H., Srot, V., van Aken, P. A., Detemple, E., Jäger, W.

{Journal of Applied Physics}, 103, 2008 (article)

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mms Kaiser, T., Sigle, W., Goll, D., Goo, N. H., Srot, V., van Aken, P. A., Detemple, E., Jäger, W. Transmission electron microscopy study of the intermixing of Fe-Pt multilayers {Journal of Applied Physics}, 103, 2008 (article)

Spin state and orbita moments across the metal-insulator-transition of REBaCo2O5.5 investigated by XMCD

Lafkioti, M., Goering, E., Gold, S., Schütz, G., Barilo, S. N., Shiryaev, S. V., Bychkov, G. L., Lemmens, P., Hinkov, V., Deisenhofer, J., Loidl, A.

{New Journal of Physics}, 10, 2008 (article)

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mms Lafkioti, M., Goering, E., Gold, S., Schütz, G., Barilo, S. N., Shiryaev, S. V., Bychkov, G. L., Lemmens, P., Hinkov, V., Deisenhofer, J., Loidl, A. Spin state and orbita moments across the metal-insulator-transition of REBaCo2O5.5 investigated by XMCD {New Journal of Physics}, 10, 2008 (article)

A crucial role for primary cilia in cortical morphogenesis

Willaredt, M. A., Hasenpusch-Theil, K., Gardner, H. A. R., Kitanovic, I., Hirschfeld-Warneken, V. C., Gojak, C. P., Gorgas, K., Bradford, C. L., Spatz, J. P., Wölfl, S., Theil, T., Tucker, K. L.

{The Journal of Neuroscience}, 28(48):12887-12900, 2008 (article)

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mms Willaredt, M. A., Hasenpusch-Theil, K., Gardner, H. A. R., Kitanovic, I., Hirschfeld-Warneken, V. C., Gojak, C. P., Gorgas, K., Bradford, C. L., Spatz, J. P., Wölfl, S., Theil, T., Tucker, K. L. A crucial role for primary cilia in cortical morphogenesis {The Journal of Neuroscience}, 28(48):12887-12900, 2008 (article)

Exchange coupled composite layers for magnetic recording

Goll, D., Macke, S., Kronmüller, H.

{Physica B}, 403, pages: 338-341, 2008 (article)

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mms Goll, D., Macke, S., Kronmüller, H. Exchange coupled composite layers for magnetic recording {Physica B}, 403, pages: 338-341, 2008 (article)

XMCD studies on Co and Li doped ZnO magnetic semiconductors

Tietze, T., Gacic, M., Schütz, G., Jakob, G., Brück, S., Goering, E.

{New Journal of Physics}, 10, 2008 (article)

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mms Tietze, T., Gacic, M., Schütz, G., Jakob, G., Brück, S., Goering, E. XMCD studies on Co and Li doped ZnO magnetic semiconductors {New Journal of Physics}, 10, 2008 (article)

Desorption studies of hydrogen in metal-organic frameworks

Panella, B., Hönes, K., Müller, U., Trukhan, N., Schubert, M., Pütter, H., Hirscher, M.

{Angewandte Chemie International Edition}, 47, pages: 2138-2142, 2008 (article)

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mms Panella, B., Hönes, K., Müller, U., Trukhan, N., Schubert, M., Pütter, H., Hirscher, M. Desorption studies of hydrogen in metal-organic frameworks {Angewandte Chemie International Edition}, 47, pages: 2138-2142, 2008 (article)

Wetting transition of grain-boundary triple junctions

Straumal, B. B., Kogtenkova, O., Zieba, P.

{Acta Materialia}, 56, pages: 925-933, 2008 (article)

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mms Straumal, B. B., Kogtenkova, O., Zieba, P. Wetting transition of grain-boundary triple junctions {Acta Materialia}, 56, pages: 925-933, 2008 (article)

Time-resolved X-ray microscopy of spin-torque-induced magnetic vortex gyration

Bolte, M., Meier, G., Krüger, B., Drews, A., Eiselt, R., Bocklage, L., Bohlens, S., Tyliszczak, T., Vansteenkiste, A., Van Waeyenberge, B., Chou, K. W., Puzic, A., Stoll, H.

{Physical Review Letters}, 100, 2008 (article)

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mms Bolte, M., Meier, G., Krüger, B., Drews, A., Eiselt, R., Bocklage, L., Bohlens, S., Tyliszczak, T., Vansteenkiste, A., Van Waeyenberge, B., Chou, K. W., Puzic, A., Stoll, H. Time-resolved X-ray microscopy of spin-torque-induced magnetic vortex gyration {Physical Review Letters}, 100, 2008 (article)

The Gilbert equation revisited: anisotropic and nonlocal damping of magnetization dynamics

Fähnle, M., Steiauf, D., Seib, J.

{Journal of Physics D}, 41, 2008 (article)

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mms Fähnle, M., Steiauf, D., Seib, J. The Gilbert equation revisited: anisotropic and nonlocal damping of magnetization dynamics {Journal of Physics D}, 41, 2008 (article)

2007

A Tutorial on Spectral Clustering

von Luxburg, U.

Statistics and Computing, 17(4):395-416, December 2007 (article)

Abstract

In recent years, spectral clustering has become one of the most popular modern clustering algorithms. It is simple to implement, can be solved efficiently by standard linear algebra software, and very often outperforms traditional clustering algorithms such as the k-means algorithm. On the first glance spectral clustering appears slightly mysterious, and it is not obvious to see why it works at all and what it really does. The goal of this tutorial is to give some intuition on those questions. We describe different graph Laplacians and their basic properties, present the most common spectral clustering algorithms, and derive those algorithms from scratch by several different approaches. Advantages and disadvantages of the different spectral clustering algorithms are discussed.

2007

ei von Luxburg, U. A Tutorial on Spectral Clustering Statistics and Computing, 17(4):395-416, December 2007 (article)

Jäkel, F., Schölkopf, B., Wichmann, F.

A Tutorial on Kernel Methods for Categorization

Journal of Mathematical Psychology, 51(6):343-358, December 2007 (article)

Abstract

The abilities to learn and to categorize are fundamental for cognitive systems, be it animals or machines, and therefore have attracted attention from engineers and psychologists alike. Modern machine learning methods and psychological models of categorization are remarkably similar, partly because these two fields share a common history in artificial neural networks and reinforcement learning. However, machine learning is now an independent and mature field that has moved beyond psychologically or neurally inspired algorithms towards providing foundations for a theory of learning that is rooted in statistics and functional analysis. Much of this research is potentially interesting for psychological theories of learning and categorization but also hardly accessible for psychologists. Here, we provide a tutorial introduction to a popular class of machine learning tools, called kernel methods. These methods are closely related to perceptrons, radial-basis-function neural networks and exemplar theories of catego rization. Recent theoretical advances in machine learning are closely tied to the idea that the similarity of patterns can be encapsulated in a positive definite kernel. Such a positive definite kernel can define a reproducing kernel Hilbert space which allows one to use powerful tools from functional analysis for the analysis of learning algorithms. We give basic explanations of some key conceptsthe so-called kernel trick, the representer theorem and regularizationwhich may open up the possibility that insights from machine learning can feed back into psychology.

ei Jäkel, F., Schölkopf, B., Wichmann, F. A Tutorial on Kernel Methods for Categorization Journal of Mathematical Psychology, 51(6):343-358, December 2007 (article)

Accurate Splice site Prediction Using Support Vector Machines

Sonnenburg, S., Schweikert, G., Philips, P., Behr, J., Rätsch, G.

BMC Bioinformatics, 8(Supplement 10):1-16, December 2007 (article)

Abstract

Background: For splice site recognition, one has to solve two classification problems: discriminating true from decoy splice sites for both acceptor and donor sites. Gene finding systems typically rely on Markov Chains to solve these tasks. Results: In this work we consider Support Vector Machines for splice site recognition. We employ the so-called weighted degree kernel which turns out well suited for this task, as we will illustrate in several experiments where we compare its prediction accuracy with that of recently proposed systems. We apply our method to the genome-wide recognition of splice sites in Caenorhabditis elegans, Drosophila melanogaster, Arabidopsis thaliana, Danio rerio, and Homo sapiens. Our performance estimates indicate that splice sites can be recognized very accurately in these genomes and that our method outperforms many other methods including Markov Chains, GeneSplicer and SpliceMachine. We provide genome-wide predictions of splice sites and a stand-alone prediction tool ready to be used for incorporation in a gene finder. Availability: Data, splits, additional information on the model selection, the whole genome predictions, as well as the stand-alone prediction tool are available for download at http:// www.fml.mpg.de/raetsch/projects/splice.

PDF DOI [BibTex]

ei Sonnenburg, S., Schweikert, G., Philips, P., Behr, J., Rätsch, G. Accurate Splice site Prediction Using Support Vector Machines BMC Bioinformatics, 8(Supplement 10):1-16, December 2007 (article)

PDF DOI [BibTex]

Experimental design for efficient identification of gene regulatory networks using sparse Bayesian models

Steinke, F., Seeger, M., Tsuda, K.

BMC Systems Biology, 1(51):1-15, November 2007 (article)

ei Steinke, F., Seeger, M., Tsuda, K. Experimental design for efficient identification of gene regulatory networks using sparse Bayesian models BMC Systems Biology, 1(51):1-15, November 2007 (article)

A unifying framework for robot control with redundant DOFs

Peters, J., Mistry, M., Udwadia, F., Nakanishi, J., Schaal, S.

Autonomous Robots, 24(1):1-12, October 2007 (article)

Abstract

Recently, Udwadia (Proc. R. Soc. Lond. A 2003:17831800, 2003) suggested to derive tracking controllers for mechanical systems with redundant degrees-of-freedom (DOFs) using a generalization of Gauss principle of least constraint. This method allows reformulating control problems as a special class of optimal controllers. In this paper, we take this line of reasoning one step further and demonstrate that several well-known and also novel nonlinear robot control laws can be derived from this generic methodology. We show experimental verifications on a Sarcos Master Arm robot for some of the derived controllers. The suggested approach offers a promising unification and simplification of nonlinear control law design for robots obeying rigid body dynamics equations, both with or without external constraints, with over-actuation or underactuation, as well as open-chain and closed-chain kinematics.

ei Peters, J., Mistry, M., Udwadia, F., Nakanishi, J., Schaal, S. A unifying framework for robot control with redundant DOFs Autonomous Robots, 24(1):1-12, October 2007 (article)

The Need for Open Source Software in Machine Learning

Sonnenburg, S., Braun, M., Ong, C., Bengio, S., Bottou, L., Holmes, G., LeCun, Y., Müller, K., Pereira, F., Rasmussen, C., Rätsch, G., Schölkopf, B., Smola, A., Vincent, P., Weston, J., Williamson, R.

Journal of Machine Learning Research, 8, pages: 2443-2466, October 2007 (article)

Abstract

Open source tools have recently reached a level of maturity which makes them suitable for building large-scale real-world systems. At the same time, the field of machine learning has developed a large body of powerful learning algorithms for diverse applications. However, the true potential of these methods is not realized, since existing implementations are not openly shared, resulting in software with low usability, and weak interoperability. We argue that this situation can be significantly improved by increasing incentives for researchers to publish their software under an open source model. Additionally, we outline the problems authors are faced with when trying to publish algorithmic implementations of machine learning methods. We believe that a resource of peer reviewed software accompanied by short articles would be highly valuable to both the machine learning and the general scientific community.

PDF Web [BibTex]

ei Sonnenburg, S., Braun, M., Ong, C., Bengio, S., Bottou, L., Holmes, G., LeCun, Y., Müller, K., Pereira, F., Rasmussen, C., Rätsch, G., Schölkopf, B., Smola, A., Vincent, P., Weston, J., Williamson, R. The Need for Open Source Software in Machine Learning Journal of Machine Learning Research, 8, pages: 2443-2466, October 2007 (article)

PDF Web [BibTex]

Some observations on the masking effects of Mach bands

Curnow, T., Cowie, DA., Henning, GB., Hill, NJ.

Journal of the Optical Society of America A, 24(10):3233-3241, October 2007 (article)

Abstract

There are 8 cycle / deg ripples or oscillations in performance as a function of location near Mach bands in experiments measuring Mach bands masking effects on random polarity signal bars. The oscillations with increments are 180 degrees out of phase with those for decrements. The oscillations, much larger than the measurement error, appear to relate to the weighting function of the spatial-frequency-tuned channel detecting the broad- band signals. The ripples disappear with step maskers and become much smaller at durations below 25 ms, implying either that the site of masking has changed or that the weighting function and hence spatial-frequency tuning is slow to develop.

ei Curnow, T., Cowie, DA., Henning, GB., Hill, NJ. Some observations on the masking effects of Mach bands Journal of the Optical Society of America A, 24(10):3233-3241, October 2007 (article)

Mining complex genotypic features for predicting HIV-1 drug resistance

Saigo, H., Uno, T., Tsuda, K.

Bioinformatics, 23(18):2455-2462, September 2007 (article)

Abstract

Human immunodeficiency virus type 1 (HIV-1) evolves in human body, and its exposure to a drug often causes mutations that enhance the resistance against the drug. To design an effective pharmacotherapy for an individual patient, it is important to accurately predict the drug resistance based on genotype data. Notably, the resistance is not just the simple sum of the effects of all mutations. Structural biological studies suggest that the association of mutations is crucial: Even if mutations A or B alone do not affect the resistance, a significant change might happen when the two mutations occur together. Linear regression methods cannot take the associations into account, while decision tree methods can reveal only limited associations. Kernel methods and neural networks implicitly use all possible associations for prediction, but cannot select salient associations explicitly. Our method, itemset boosting, performs linear regression in the complete space of power sets of mutations. It implements a forward feature selection procedure where, in each iteration, one mutation combination is found by an efficient branch-and-bound search. This method uses all possible combinations, and salient associations are explicitly shown. In experiments, our method worked particularly well for predicting the resistance of nucleotide reverse transcriptase inhibitors (NRTIs). Furthermore, it successfully recovered many mutation associations known in biological literature.

ei Saigo, H., Uno, T., Tsuda, K. Mining complex genotypic features for predicting HIV-1 drug resistance Bioinformatics, 23(18):2455-2462, September 2007 (article)

Real-Time Fetal Heart Monitoring in Biomagnetic Measurements Using Adaptive Real-Time ICA

Waldert, S., Bensch, M., Bogdan, M., Rosenstiel, W., Schölkopf, B., Lowery, C., Eswaran, H., Preissl, H.

IEEE Transactions on Biomedical Engineering, 54(10):1867-1874, September 2007 (article)

Abstract

Electrophysiological signals of the developing fetal brain and heart can be investigated by fetal magnetoencephalography (fMEG). During such investigations, the fetal heart activity and that of the mother should be monitored continuously to provide an important indication of current well-being. Due to physical constraints of an fMEG system, it is not possible to use clinically established heart monitors for this purpose. Considering this constraint, we developed a real-time heart monitoring system for biomagnetic measurements and showed its reliability and applicability in research and for clinical examinations. The developed system consists of real-time access to fMEG data, an algorithm based on Independent Component Analysis (ICA), and a graphical user interface (GUI). The algorithm extracts the current fetal and maternal heart signal from a noisy and artifact-contaminated data stream in real-time and is able to adapt automatically to continuously varying environmental parameters. This algorithm has been na med Adaptive Real-time ICA (ARICA) and is applicable to real-time artifact removal as well as to related blind signal separation problems.

ei Waldert, S., Bensch, M., Bogdan, M., Rosenstiel, W., Schölkopf, B., Lowery, C., Eswaran, H., Preissl, H. Real-Time Fetal Heart Monitoring in Biomagnetic Measurements Using Adaptive Real-Time ICA IEEE Transactions on Biomedical Engineering, 54(10):1867-1874, September 2007 (article)

Book Review: Computational Intelligence: Principles, Techniques and Applications by Amit Konar

Peters, J.

The Computer Journal, 50(6):758-758, September 2007 (article)

ei Peters, J. Book Review: Computational Intelligence: Principles, Techniques and Applications by Amit Konar The Computer Journal, 50(6):758-758, September 2007 (article)

Feature Selection for Trouble Shooting in Complex Assembly Lines

Pfingsten, T., Herrmann, D., Schnitzler, T., Feustel, A., Schölkopf, B.

IEEE Transactions on Automation Science and Engineering, 4(3):465-469, July 2007 (article)

Abstract

The final properties of sophisticated products can be affected by many unapparent dependencies within the manufacturing process, and the products integrity can often only be checked in a final measurement. Troubleshooting can therefore be very tedious if not impossible in large assembly lines. In this paper we show that Feature Selection is an efficient tool for serial-grouped lines to reveal causes for irregularities in product attributes. We compare the performance of several methods for Feature Selection on real-world problems in mass-production of semiconductor devices. Note to Practitioners We present a data based procedure to localize flaws in large production lines: using the results of final quality inspections and information about which machines processed which batches, we are able to identify machines which cause low yield.

ei Pfingsten, T., Herrmann, D., Schnitzler, T., Feustel, A., Schölkopf, B. Feature Selection for Trouble Shooting in Complex Assembly Lines IEEE Transactions on Automation Science and Engineering, 4(3):465-469, July 2007 (article)

Gene selection via the BAHSIC family of algorithms

Song, L., Bedo, J., Borgwardt, K., Gretton, A., Smola, A.

Bioinformatics, 23(13: ISMB/ECCB 2007 Conference Proceedings):i490-i498, July 2007 (article)

Abstract

Motivation: Identifying significant genes among thousands of sequences on a microarray is a central challenge for cancer research in bioinformatics. The ultimate goal is to detect the genes that are involved in disease outbreak and progression. A multitude of methods have been proposed for this task of feature selection, yet the selected gene lists differ greatly between different methods. To accomplish biologically meaningful gene selection from microarray data, we have to understand the theoretical connections and the differences between these methods. In this article, we define a kernel-based framework for feature selection based on the Hilbert–Schmidt independence criterion and backward elimination, called BAHSIC. We show that several well-known feature selectors are instances of BAHSIC, thereby clarifying their relationship. Furthermore, by choosing a different kernel, BAHSIC allows us to easily define novel feature selection algorithms. As a further advantage, feature selection via BAHSIC works directly on multiclass problems. Results: In a broad experimental evaluation, the members of the BAHSIC family reach high levels of accuracy and robustness when compared to other feature selection techniques. Experiments show that features selected with a linear kernel provide the best classification performance in general, but if strong non-linearities are present in the data then non-linear kernels can be more suitable.

ei Song, L., Bedo, J., Borgwardt, K., Gretton, A., Smola, A. Gene selection via the BAHSIC family of algorithms Bioinformatics, 23(13: ISMB/ECCB 2007 Conference Proceedings):i490-i498, July 2007 (article)

Phenotyping of Chondrocytes In Vivo and In Vitro Using cDNA Array Technology

Zien, A., Gebhard, P., Fundel, K., Aigner, T.

Clinical Orthopaedics and Related Research, 460, pages: 226-233, July 2007 (article)

Abstract

The cDNA array technology is a powerful tool to analyze a high number of genes in parallel. We investigated whether large-scale gene expression analysis allows clustering and identification of cellular phenotypes of chondrocytes in different in vivo and in vitro conditions. In 100% of cases, clustering analysis distinguished between in vivo and in vitro samples, suggesting fundamental differences in chondrocytes in situ and in vitro regardless of the culture conditions or disease status. It also allowed us to differentiate between healthy and osteoarthritic cartilage. The clustering also revealed the relative importance of the investigated culturing conditions (stimulation agent, stimulation time, bead/monolayer). We augmented the cluster analysis with a statistical search for genes showing differential expression. The identified genes provided hints to the molecular basis of the differences between the sample classes. Our approach shows the power of modern bioinformatic algorithms for understanding and class ifying chondrocytic phenotypes in vivo and in vitro. Although it does not generate new experimental data per se, it provides valuable information regarding the biology of chondrocytes and may provide tools for diagnosing and staging the osteoarthritic disease process.

ei Zien, A., Gebhard, P., Fundel, K., Aigner, T. Phenotyping of Chondrocytes In Vivo and In Vitro Using cDNA Array Technology Clinical Orthopaedics and Related Research, 460, pages: 226-233, July 2007 (article)