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2000


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The liquid ferromagnet Co80Pd20 and its critical exponent γ

Bührer, C., Beckmann, M., Fähnle, M., Maier, K.

{Journal of Magnetism and Magnetic Materials}, 212, pages: 211-224, 2000 (article)

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2000


[BibTex]


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Irreversible magnetization processes in a soft magnetic platelet

Hertel, R., Kronmüller, H.

{Physica B}, 275, pages: 1-4, 2000 (article)

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[BibTex]


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Micromagnetic and microstructural analysis of the temperature dependence of the coercive field of Sm2(Co, Cu, Fe, Zr)17 permanent magnets

Goll, D., Sigle, W., Hadjipanayis, G. C., Kronmüller, H.

In Proceedings of the 16th International Workshop on Rare-Earth Magnets and Their Applications, pages: 61-70, Kaneko, H.; Homma, M.; Okada, M., 2000 (inproceedings)

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[BibTex]


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Measurement of the Zener relaxation in high-purity FeCr single crystals

Hirscher, M., Brossmann, U., Henes, R.

{Materials Transactions, JIM}, 41, pages: 82-86, 2000 (article)

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[BibTex]


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Ab-initio statistical mechanics for alloy phase diagrams and ordering phenomena including the effect of vacancies

Lechermann, F., Fähnle, M.

{Physical Review B}, 63, 2000 (article)

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[BibTex]


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MeV Positron Beams

Stoll, H.

In Positron Beams and Their Applications, pages: 237-257, World Scientific, Singapore, 2000 (incollection)

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[BibTex]


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Reactions in TiO2/Ti3Al and TiO2/TiAl bilayers: Application of target-factor analysis in auger electron spectroscopy

van Lier, J., Baretzky, B., Zalar, A., Mittemeijer, E. J.

{Surface and Interface Analysis}, 30, pages: 124-129, 2000 (article)

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[BibTex]


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Ab-initio treatment of noncollinear spin systems within the atomic-sphere approximation and beyond

Grotheer, O., Ederer, C., Fähnle, M.

{Physical Review B}, 62, pages: 5601-5608, 2000 (article)

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[BibTex]

[BibTex]


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On-line learning for humanoid robot systems

Conradt, J., Tevatia, G., Vijayakumar, S., Schaal, S.

In Proceedings of the Seventeenth International Conference on Machine Learning (ICML 2000), 1, pages: 191-198, Stanford, CA, 2000, clmc (inproceedings)

Abstract
Humanoid robots are high-dimensional movement systems for which analytical system identification and control methods are insufficient due to unknown nonlinearities in the system structure. As a way out, supervised learning methods can be employed to create model-based nonlinear controllers which use functions in the control loop that are estimated by learning algorithms. However, internal models for humanoid systems are rather high-dimensional such that conventional learning algorithms would suffer from slow learning speed, catastrophic interference, and the curse of dimensionality. In this paper we explore a new statistical learning algorithm, locally weighted projection regression (LWPR), for learning internal models in real-time. LWPR is a nonparametric spatially localized learning system that employs the less familiar technique of partial least squares regression to represent functional relationships in a piecewise linear fashion. The algorithm can work successfully in very high dimensional spaces and detect irrelevant and redundant inputs while only requiring a computational complexity that is linear in the number of input dimensions. We demonstrate the application of the algorithm in learning two classical internal models of robot control, the inverse kinematics and the inverse dynamics of an actual seven degree-of-freedom anthropomorphic robot arm. For both examples, LWPR can achieve excellent real-time learning results from less than one hour of actual training data.

am

link (url) [BibTex]

link (url) [BibTex]


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Humanoid Robot DB

Kotosaka, S., Shibata, T., Schaal, S.

In Proceedings of the International Conference on Machine Automation (ICMA2000), pages: 21-26, 2000, clmc (inproceedings)

am

[BibTex]

[BibTex]


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Wing transmission for a micromechanical flying insect

Fearing, R. S., Chiang, K. H., Dickinson, M. H., Pick, D., Sitti, M., Yan, J.

In Robotics and Automation, 2000. Proceedings. ICRA’00. IEEE International Conference on, 2, pages: 1509-1516, 2000 (inproceedings)

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[BibTex]

[BibTex]


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Is d-Al-Cu-Co a random tiling?

Zeger, G., Plachke, D., Carstanjen, H. D., Trebin, H. R.

{Materials Science and Engineering A}, 294, pages: 291-294, 2000 (article)

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[BibTex]


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Nonlinear magnetoelastic coupling coefficients in Fe from an ab-initio calculation

Komelj, M., Fähnle, M.

{Journal of Magnetism and Magnetic Materials}, 220, pages: L 7-L 12, 2000 (article)

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[BibTex]

[BibTex]


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Current densities in low-angle grain boundaries of YBCO

Albrecht, J., Warthmann, R., Leonhardt, S., Kronmüller, H.

{Physica C}, 341-348, pages: 1459-1460, 2000 (article)

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[BibTex]


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The hydrogen desorption kinetics of Pd-coated LaNi5-type films

Cuevas, F., Hirscher, M.

{Journal of Alloys and Compounds}, 313, pages: 269-275, 2000 (article)

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The structure of the trihydride GdH3

Ellner, M., Reule, H., Mittemeijer, E. J.

{Journal of Alloys and Compounds}, 309, pages: 127-131, 2000 (article)

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[BibTex]


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Corrosion resistance of the vacuum arc deposited Ti, TiN and TiO2 coatings on large area glass substrates

Vershinin, N., Filonov, K., Straumal, B., Gust, W., Dimitriou, R., Kovalev, A., Camacho, J.

{Surface and Coatings Technology}, 125, pages: 223-228, 2000 (article)

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[BibTex]


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Is the insulator-metal transition in perovskites associated with the bulk magnetic phase transition?

Baszynski, J., Walz, F., Tolinski, T.

{Sensors and Actuators}, 81, pages: 37-39, 2000 (article)

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[BibTex]


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Correlated molecular-field theory of amorphous ferromagnets and the Gibbs free energy

Fähnle, M.

{Journal of Magnetism and Magnetic Materials}, 210, pages: L 1-L 4, 2000 (article)

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[BibTex]

[BibTex]


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Pinning mechanism of vortices at antiphase boundaries in YBa2Cu3O7-δ

Jooss, C., Warthmann, R., Kronmüller, H.

{Physical Review B}, 61, pages: 12433-12446, 2000 (article)

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Critical behaviour of V2H in a defective near-surface skin layer

Trenkler, J., Moss, S. C., Reichert, H., Paniago, R., Gebhardt, U., Carstanjen, H. D., Metzger, T. H., Peisl, J.

In Exploration of Subsurface Phenomena by Particle Scattering, pages: 155-164, International Advanced Studies Institute IASI Press, North East/MD, 2000 (incollection)

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Spectral distribution of activation energies in YBa2Cu3O7-δthin films

Warthmann, R., Albrecht, J., Kronmüller, H., Joos, C.

{Physical Review B}, 62, pages: 15226-15229, 2000 (article)

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[BibTex]

[BibTex]


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Ab-initio calculation of the formation and migration energies for Monovacancies in Mg

Krimmel, H., Fähnle, M.

{Physical Review B}, 62, pages: 5489-5491, 2000 (article)

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[BibTex]

[BibTex]


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Controlled pushing of nanoparticles: modeling and experiments

Sitti, M., Hashimoto, H.

IEEE/ASME transactions on mechatronics, 5(2):199-211, IEEE, 2000 (article)

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[BibTex]

[BibTex]


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Investigation of strain softening of icosahedral AlPdMn single quasicrystals

Brunner, D., Plachke, D., Carstanjen, H. D.

{Physica Status Solidi (A)}, 177, pages: 203-217, 2000 (article)

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Formation and evolution of the transverse anisotropy with nanocrystallization in amorphous Fe73.5CuNb3Si13.5B9 ribbons

Guo, H. Q., Kronmüller, H., Dragon, T., Cheng, Z. H., Shen, B. G.

{Physical Review}, 62, pages: 5760-5764, 2000 (article)

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Deflection of 32.8 TeV/c fully stripped Pb ions by means of a bent Si crystal

Biino, C., Clement, M., Doble, N., Elsener, K., Gatignon, L., Grafström, P., Herr, W., Keppler, P., Major, J., Mikkelsen, U., Taratin, A., Velasco, M.

{Nuclear Instruments and Methods in Physics Research B}, 160, pages: 536-543, 2000 (article)

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Replacing muons by protons: polarized beam NMR

Schüth, J., Eversheim, P.-D., Herzog, P., Maier, K., Majer, G., Meyer, P., Roduner, E.

{Physica B}, 289-290, pages: 672-675, 2000 (article)

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Charge transport mechanisms in single crystalline yttrium iron garnet as resolved by magnetic relaxation

Walz, F., Torres, L., Iñiguez, J., Kronmüller, H.

{Physica Status Solidi (A)}, 180, pages: 507-522, 2000 (article)

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[BibTex]


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Theory of self-diffusion in alkali metals I. Results for monovacancies in Li, Na, and K

Schott, V., Fähnle, M., Madden, P. A.

{Journal of Physics: Condensed Matter}, 12, pages: 1171-1194, 2000 (article)

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Theory of self-diffusion in alkali metals II. The influence of divacancies in Li

Schott, V., Fähnle, M., Madden, P. A.

{Journal of Physics: Condensed Matter}, 12, pages: 1195-1198, 2000 (article)

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[BibTex]

[BibTex]


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Decay kinetics of nonequilibrium Al-Si solid solutions

Sluchanko, N. E., Glushkov, V. V., Demishev, S. V., Kondrin, M. V., Ischenko, T. V., Gust, W., Brazhkin, V. V., Straumal, B. B., Bruynseraede, Y., Moshchalkov, V. V.

{Physical Review B}, 61, pages: 6019-6027, 2000 (article)

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[BibTex]


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Vacuum arc deposition of Ti coatings

Straumal, B., Gust, W., Vershinin, N., Dimitriou, R., Rabkin, E.

{Surface and Coatings Technology}, 125, pages: 157-160, 2000 (article)

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[BibTex]

[BibTex]


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Internal friction in Ni-rich B2-NiAl

Brossmann, U., Hirscher, M., Schaible, D., Kronmüller, H.

{Scripta Materialia}, 42, pages: 1193-1197, 2000 (article)

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[BibTex]

[BibTex]


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Spectral distribution of activation energies in YBa2Cu3O7-δthin films

Warthmann, R., Albrecht, J., Kronmüller, H., Joos, C.

{Physical Review B}, 62, pages: 15226-15229, 2000 (article)

mms

[BibTex]

[BibTex]


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Pre-treatment of large area strips with the aid of a high power hall current accelerator

Vershinin, N., Dimitriou, R., Benmalek, M., Straumal, B., Gust, W., Vivas, J., Shulga, J.

{Surface and Coatings Technology}, 125, pages: 35-39, 2000 (article)

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[BibTex]

[BibTex]

1998


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Programmable pattern generators

Schaal, S., Sternad, D.

In 3rd International Conference on Computational Intelligence in Neuroscience, pages: 48-51, Research Triangle Park, NC, Oct. 24-28, October 1998, clmc (inproceedings)

Abstract
This paper explores the idea to create complex human-like arm movements from movement primitives based on nonlinear attractor dynamics. Each degree-of-freedom of an arm is assumed to have two independent abilities to create movement, one through a discrete dynamic system, and one through a rhythmic system. The discrete system creates point-to-point movements based on internal or external target specifications. The rhythmic system can add an additional oscillatory movement relative to the current position of the discrete system. In the present study, we develop appropriate dynamic systems that can realize the above model, motivate the particular choice of the systems from a biological and engineering point of view, and present simulation results of the performance of such movement primitives. Implementation results on a Sarcos Dexterous Arm are discussed.

am

link (url) [BibTex]

1998


link (url) [BibTex]


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SVMs — a practical consequence of learning theory

Schölkopf, B.

IEEE Intelligent Systems and their Applications, 13(4):18-21, July 1998 (article)

Abstract
My first exposure to Support Vector Machines came this spring when heard Sue Dumais present impressive results on text categorization using this analysis technique. This issue's collection of essays should help familiarize our readers with this interesting new racehorse in the Machine Learning stable. Bernhard Scholkopf, in an introductory overview, points out that a particular advantage of SVMs over other learning algorithms is that it can be analyzed theoretically using concepts from computational learning theory, and at the same time can achieve good performance when applied to real problems. Examples of these real-world applications are provided by Sue Dumais, who describes the aforementioned text-categorization problem, yielding the best results to date on the Reuters collection, and Edgar Osuna, who presents strong results on application to face detection. Our fourth author, John Platt, gives us a practical guide and a new technique for implementing the algorithm efficiently.

ei

PDF Web DOI [BibTex]

PDF Web DOI [BibTex]


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Prior knowledge in support vector kernels

Schölkopf, B., Simard, P., Smola, A., Vapnik, V.

In Advances in Neural Information Processing Systems 10, pages: 640-646 , (Editors: M Jordan and M Kearns and S Solla ), MIT Press, Cambridge, MA, USA, Eleventh Annual Conference on Neural Information Processing (NIPS), June 1998 (inproceedings)

ei

PDF Web [BibTex]

PDF Web [BibTex]


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From regularization operators to support vector kernels

Smola, A., Schölkopf, B.

In Advances in Neural Information Processing Systems 10, pages: 343-349, (Editors: M Jordan and M Kearns and S Solla), MIT Press, Cambridge, MA, USA, 11th Annual Conference on Neural Information Processing (NIPS), June 1998 (inproceedings)

ei

PDF Web [BibTex]

PDF Web [BibTex]


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Learning view graphs for robot navigation

Franz, M., Schölkopf, B., Mallot, H., Bülthoff, H.

Autonomous Robots, 5(1):111-125, March 1998 (article)

Abstract
We present a purely vision-based scheme for learning a topological representation of an open environment. The system represents selected places by local views of the surrounding scene, and finds traversable paths between them. The set of recorded views and their connections are combined into a graph model of the environment. To navigate between views connected in the graph, we employ a homing strategy inspired by findings of insect ethology. In robot experiments, we demonstrate that complex visual exploration and navigation tasks can thus be performed without using metric information.

ei

PDF PDF DOI [BibTex]

PDF PDF DOI [BibTex]


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Surface second-order nonlinear optical activity

Fischer, P., Buckingham, A.

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS, 15(12):2951-2957, 1998 (article)

Abstract
Following the recent observation of a large second-harmonic intensity difference from a monolayer of chiral molecules with left and right circularly polarized light, the scattering theory is generalized and extended to predict linear and circular intensity differences for the more Versatile sum-frequency spectroscopy. Estimates indicate that intensity differences should be detectable for a typical experimental arrangement. The second-order nonlinear surface susceptibility tensor is given for different surface point groups in the electric dipole approximation; it is shown that nonlinear optical activity phenomena unambiguously probe molecular chirality only for molecular monolayers that are symmetric about the normal. Other surface symmetries can give rise to intensity differences from monolayers composed of achiral molecules. A water surface is predicted to show Linear and nonlinear optical activity in the presence of an electric field parallel to the surface. (C) 1998 Optical Society of America {[}S0740-3224(98)01311-3] OCIS codes: 190.0190, 190.4350, 240.6490.

pf

DOI [BibTex]

DOI [BibTex]


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Linear electro-optic effect in optically active liquids

Buckingham, A., Fischer, P.

CHEMICAL PHYSICS LETTERS, 297(3-4):239-246, 1998 (article)

Abstract
A linear effect of an electrostatic field F on the intensity of sum- and difference-frequency generation in a chiral liquid is predicted. It arises in the electric dipole approximation. The effect changes sign with the enantiomer and on reversing the direction of the electrostatic field. The sum-frequency generator chi(alpha beta gamma)((2)) (-omega(3);omega(1),omega(2)), where omega(3) = omega(1) + omega(2), and the electric field-induced sum-frequency generator chi(alpha beta gamma delta)((3))(-omega(3);omega(1),omega(2),0)F-delta interfere and their contributions to the scattering power can be distinguished. Encouraging predictions are given for a typical experimental arrangement. (C) 1998 Elsevier Science B.V. All rights reserved.

pf

DOI [BibTex]

DOI [BibTex]


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Monolayers of hexadecyltrimethylammonium p-tosylate at the air-water interface. 1. Sum-frequency spectroscopy

Bell, G., Li, Z., Bain, C., Fischer, P., Duffy, D.

JOURNAL OF PHYSICAL CHEMISTRY B, 102(47):9461-9472, 1998 (article)

Abstract
Sum-frequency vibrational spectroscopy has been used to determine the structure of monolayers of the cationic surfactant, hexadecyltrimethylammonium p-tosylate (C(16)TA(+)Ts(-)), at the surface of water. Selective deuteration of the cation or the anion allowed the separate detection of sum-frequency spectra of the surfactant and of counterions that are bound to the monolayer. The p-tosylate ions an oriented with their methyl groups pointing away from the aqueous subphase and with the C-2 axis tilted, on average, by 30-40 degrees from the surface normal. The vibrational spectra of C(16)TA(+) indicate that the number of gauche defects in the monolayer does not change dramatically when bromide counterions are replaced by p-tosylate. The ends of the hydrocarbon chains of C16TA+ are, however, tilted much further from the surface normal in the presence of p-tosylate than in the presence of bromide. A quantitative analysis of the sum-frequency spectra requires a knowledge of the molecular hyperpolarizability tensor: the role of ab initio calculations and Raman spectroscopy in determining the components of this tensor is discussed.

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DOI [BibTex]

DOI [BibTex]


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Ultraviolet resonance Raman study of drug binding in dihydrofolate reductase, gyrase, and catechol O-methyltransferase

Couling, V., Fischer, P., Klenerman, D., Huber, W.

BIOPHYSICAL JOURNAL, 75(2):1097-1106, 1998 (article)

Abstract
This paper presents a study of the use of ultraviolet resonance Raman (UVRR) spectroscopic methods as a means of elucidating aspects of drug-protein interactions. Some of the RR vibrational bands of the aromatic amino acids tyrosine and tryptophan are sensitive to the microenvironment, and the use of UV excitation radiation allows selective enhancement of the spectral features of the aromatic amino acids, enabling observation specifically of their change in microenvironment upon drug binding. The three drug-protein systems investigated in this study are dihydrofolate reductase with its inhibitor trimethoprim, gyrase with novobiocin, and catechol O-methyltransferase with dinitrocatechol. It is demonstrated that UVRR spectroscopy has adequate sensitivity to be a useful means of detecting drug-protein interactions in those systems for which the electronic absorption of the aromatic amino acids changes because of hydrogen bonding and/or possible dipole-dipole and dipole-polarizability interactions with the ligand.

pf

DOI [BibTex]

DOI [BibTex]


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Robust local learning in high dimensional spaces

Vijayakumar, S., Schaal, S.

In 5th Joint Symposium on Neural Computation, pages: 186-193, Institute for Neural Computation, University of California, San Diego, San Diego, CA, 1998, clmc (inproceedings)

Abstract
Incremental learning of sensorimotor transformations in high dimensional spaces is one of the basic prerequisites for the success of autonomous robot devices as well as biological movement systems. So far, due to sparsity of data in high dimensional spaces, learning in such settings requires a significant amount of prior knowledge about the learning task, usually provided by a human expert. In this paper, we suggest a partial revision of this view. Based on empirical studies, we observed that, despite being globally high dimensional and sparse, data distributions from physical movement systems are locally low dimensional and dense. Under this assumption, we derive a learning algorithm, Locally Adaptive Subspace Regression, that exploits this property by combining a dynamically growing local dimensionality reduction technique as a preprocessing step with a nonparametric learning technique, locally weighted regression, that also learns the region of validity of the regression. The usefulness of the algorithm and the validity of its assumptions are illustrated for a synthetic data set, and for data of the inverse dynamics of human arm movements and an actual 7 degree-of-freedom anthropomorphic robot arm.

am

[BibTex]

[BibTex]


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Tele-nanorobotics using an atomic force microscope as a nanorobot and sensor

Sitti, M., Hashimoto, H.

Advanced Robotics, 13(4):417-436, Taylor & Francis, 1998 (article)

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[BibTex]

[BibTex]