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2010


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Dimensional Reduction of High-Frequency Accelerations for Haptic Rendering

Landin, N., Romano, J. M., McMahan, W., Kuchenbecker, K. J.

In Haptics: Generating and Perceiving Tangible Sensations: Part II (Proceedings of EuroHaptics), 6192, pages: 79-86, Lecture Notes in Computer Science, Springer, Amsterdam, Netherlands, 2010, Poster presentation given by Landin (inproceedings)

hi

[BibTex]

2010


[BibTex]


Graph signature for self-reconfiguration planning of modules with symmetry
Graph signature for self-reconfiguration planning of modules with symmetry

Asadpour, M., Ashtiani, M. H. Z., Spröwitz, A., Ijspeert, A. J.

In Proceedings of the 2009 IEEE/RSJ International Conference on Intelligent Robots and Systems, pages: 5295-5300, IEEE, St. Louis, MO, 2010 (inproceedings)

Abstract
In our previous works we had developed a framework for self-reconfiguration planning based on graph signature and graph edit-distance. The graph signature is a fast isomorphism test between different configurations and the graph edit-distance is a similarity metric. But the algorithm is not suitable for modules with symmetry. In this paper we improve the algorithm in order to deal with symmetric modules. Also, we present a new heuristic function to guide the search strategy by penalizing the solutions with more number of actions. The simulation results show the new algorithm not only deals with symmetric modules successfully but also finds better solutions in a shorter time.

dlg

DOI [BibTex]

DOI [BibTex]


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Policy learning algorithmis for motor learning (Algorithmen zum automatischen Erlernen von Motorfähigkigkeiten)

Peters, J., Kober, J., Schaal, S.

Automatisierungstechnik, 58(12):688-694, 2010, clmc (article)

Abstract
Robot learning methods which allow au- tonomous robots to adapt to novel situations have been a long standing vision of robotics, artificial intelligence, and cognitive sciences. However, to date, learning techniques have yet to ful- fill this promise as only few methods manage to scale into the high-dimensional domains of manipulator robotics, or even the new upcoming trend of humanoid robotics. If possible, scaling was usually only achieved in precisely pre-structured domains. In this paper, we investigate the ingredients for a general ap- proach policy learning with the goal of an application to motor skill refinement in order to get one step closer towards human- like performance. For doing so, we study two major components for such an approach, i. e., firstly, we study policy learning algo- rithms which can be applied in the general setting of motor skill learning, and, secondly, we study a theoretically well-founded general approach to representing the required control structu- res for task representation and execution.

am

link (url) [BibTex]


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Modellbasierte Echtzeit-Bewegungsschätzung in der Fluoreszenzendoskopie

Stehle, T., Wulff, J., Behrens, A., Gross, S., Aach, T.

In Bildverarbeitung für die Medizin, 574, pages: 435-439, CEUR Workshop Proceedings, Bildverarbeitung für die Medizin, 2010 (inproceedings)

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pdf [BibTex]

pdf [BibTex]


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VerroTouch: A Vibrotactile Feedback System for Minimally Invasive Robotic Surgery

Kuchenbecker, K. J., Gewirtz, J., McMahan, W., Standish, D., Bohren, J., Martin, P., Wedmid, A., Mendoza, P. J., Lee, D. I.

In Proc. 28th World Congress of Endourology, 2010, PS8-14. Poster presentation given by Wedmid (inproceedings)

hi

[BibTex]

[BibTex]


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On a disparity between relative cliquewidth and relative NLC-width

Müller, H., Urner, R.

Discrete Applied Mathematics, 158(7):828-840, 2010 (article)

ei

link (url) DOI [BibTex]

link (url) DOI [BibTex]


{Robust one-shot 3D scanning using loopy belief propagation}
Robust one-shot 3D scanning using loopy belief propagation

Ulusoy, A., Calakli, F., Taubin, G.

In Computer Vision and Pattern Recognition Workshops (CVPRW), 2010 IEEE Computer Society Conference on, pages: 15-22, IEEE, 2010 (inproceedings)

Abstract
A structured-light technique can greatly simplify the problem of shape recovery from images. There are currently two main research challenges in design of such techniques. One is handling complicated scenes involving texture, occlusions, shadows, sharp discontinuities, and in some cases even dynamic change; and the other is speeding up the acquisition process by requiring small number of images and computationally less demanding algorithms. This paper presents a “one-shot” variant of such techniques to tackle the aforementioned challenges. It works by projecting a static grid pattern onto the scene and identifying the correspondence between grid stripes and the camera image. The correspondence problem is formulated using a novel graphical model and solved efficiently using loopy belief propagation. Unlike prior approaches, the proposed approach uses non-deterministic geometric constraints, thereby can handle spurious connections of stripe images. The effectiveness of the proposed approach is verified on a variety of complicated real scenes.

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pdf link (url) DOI [BibTex]

pdf link (url) DOI [BibTex]


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Naı̈ve Security in a Wi-Fi World

Swanson, C., Urner, R., Lank, E.

In Trust Management IV - 4th IFIP WG 11.11 International Conference Proceedings, pages: 32-47, (Editors: Nishigaki, M., Josang, A., Murayama, Y., Marsh, S.), IFIPTM, 2010 (inproceedings)

ei

link (url) DOI [BibTex]

link (url) DOI [BibTex]


Roombots - Towards decentralized reconfiguration with self-reconfiguring modular robotic metamodules
Roombots - Towards decentralized reconfiguration with self-reconfiguring modular robotic metamodules

Spröwitz, A., Laprade, P., Bonardi, S., Mayer, M., Moeckel, R., Mudry, P., Ijspeert, A. J.

In Proceedings of the 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages: 1126-1132, IEEE, Taipeh, 2010 (inproceedings)

Abstract
This paper presents our work towards a decentralized reconfiguration strategy for self-reconfiguring modular robots, assembling furniture-like structures from Roombots (RB) metamodules. We explore how reconfiguration by loco- motion from a configuration A to a configuration B can be controlled in a distributed fashion. This is done using Roombots metamodules—two Roombots modules connected serially—that use broadcast signals, lookup tables of their movement space, assumptions about their neighborhood, and connections to a structured surface to collectively build desired structures without the need of a centralized planner.

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DOI [BibTex]

DOI [BibTex]


Roombots: Reconfigurable Robots for Adaptive Furniture
Roombots: Reconfigurable Robots for Adaptive Furniture

Spröwitz, A., Pouya, S., Bonardi, S., van den Kieboom, J., Möckel, R., Billard, A., Dillenbourg, P., Ijspeert, A.

Computational Intelligence Magazine, IEEE, 5(3):20-32, 2010 (article)

Abstract
Imagine a world in which our furniture moves around like legged robots, interacts with us, and changes shape and function during the day according to our needs. This is the long term vision we have in the Roombots project. To work towards this dream, we are developing modular robotic modules that have rotational degrees of freedom for locomotion as well as active connection mechanisms for runtime reconfiguration. A piece of furniture, e.g. a stool, will thus be composed of several modules that activate their rotational joints together to implement locomotor gaits, and will be able to change shape, e.g. transforming into a chair, by sequences of attachments and detachments of modules. In this article, we firstly present the project and the hardware we are currently developing. We explore how reconfiguration from a configuration A to a configuration B can be controlled in a distributed fashion. This is done using metamodules-two Roombots modules connected serially-that use broadcast signals and connections to a structured ground to collectively build desired structures without the need of a centralized planner. We then present how locomotion controllers can be implemented in a distributed system of coupled oscillators-one per degree of freedom-similarly to the concept of central pattern generators (CPGs) found in the spinal cord of vertebrate animals. The CPGs are based on coupled phase oscillators to ensure synchronized behavior and have different output filters to allow switching between oscillations and rotations. A stochastic optimization algorithm is used to explore optimal CPG configurations for different simulated Roombots structures.

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DOI [BibTex]

DOI [BibTex]


Scene Carving: Scene Consistent Image Retargeting
Scene Carving: Scene Consistent Image Retargeting

Mansfield, A., Gehler, P., Van Gool, L., Rother, C.

In European Conference on Computer Vision (ECCV), 2010 (inproceedings)

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webpage+code pdf supplementary poster [BibTex]

webpage+code pdf supplementary poster [BibTex]


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Gait planning based on kinematics for a quadruped gecko model with redundancy

Son, D., Jeon, D., Nam, W. C., Chang, D., Seo, T., Kim, J.

Robotics and Autonomous Systems, 58, 2010 (article)

pi

[BibTex]

[BibTex]


Epione: An Innovative Pain Management System Using Facial Expression Analysis, Biofeedback and Augmented Reality-Based Distraction
Epione: An Innovative Pain Management System Using Facial Expression Analysis, Biofeedback and Augmented Reality-Based Distraction

Georgoulis, S., Eleftheriadis, S., Tzionas, D., Vrenas, K., Petrantonakis, P., Hadjileontiadis, L. J.

In Proceedings of the 2010 International Conference on Intelligent Networking and Collaborative Systems, pages: 259-266, INCOS ’10, IEEE Computer Society, Washington, DC, USA, 2010 (inproceedings)

Abstract
An innovative pain management system, namely Epione, is presented here. Epione deals with three main types of pain, i.e., acute pain, chronic pain, and phantom limb pain. In particular, by using facial expression analysis, Epione forms a dynamic pain meter, which then triggers biofeedback and augmented reality-based destruction scenarios, in an effort to maximize patient's pain relief. This unique combination sets Epione not only a novel pain management approach, but also a means that provides an understanding and integration of the needs of the whole community involved i.e., patients and physicians, in a joint attempt to facilitate easing of their suffering, provide efficient monitoring and contribute to a better quality of life.

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Paper Project Page DOI [BibTex]

Paper Project Page DOI [BibTex]


Automatic Gait Generation in Modular Robots: to Oscillate or to Rotate? that is the question
Automatic Gait Generation in Modular Robots: to Oscillate or to Rotate? that is the question

Pouya, S., van den Kieboom, J., Spröwitz, A., Ijspeert, A. J.

In Proceedings of the 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages: 514-520, IEEE, Taipei, 2010 (inproceedings)

Abstract
Modular robots offer the possibility to design robots with a high diversity of shapes and functionalities. This nice feature also brings an important challenge: namely how to design efficient locomotion gaits for arbitrary robot structures with many degrees of freedom. In this paper, we present a framework that allows one to explore and identify highly different gaits for a given arbitrary- shaped modular robot. We use simulated robots made of several Roombots modules that have three rotational joints each. These modules have the interesting feature that they can produce both oscillatory movements (i.e. periodic movements around a rest position) and rotational movements (i.e. with continuously increasing angle), leading to very rich locomotion patterns. Here we ask ourselves which types of movements —purely oscillatory, purely rotational, or a combination of both— lead to the fastest gaits. To address this question we designed a control architecture based on a distributed system of coupled phase oscillators that can produce synchronized rotations and oscillations in many degrees of freedom. We also designed a specific optimization algorithm that can automatically design hybrid controllers, i.e. controllers that use oscillations in some joints and rotations in others, for fast gaits. The proposed framework is verified by multiple simulations for several robot morphologies. The results show that (i) the question whether it is better to oscillate or to rotate depends on the morphology of the robot, and that in general it is best to do both, (ii) the optimization framework can successfully generate hybrid controllers that outperform purely oscillatory and purely rotational ones, and (iii) the resulting gaits are fast, innovative, and would have been hard to design by hand.

dlg

DOI [BibTex]

DOI [BibTex]


Molecular QED of coherent and incoherent sum-frequency and second-harmonic generation in chiral liquids in the presence of a static electric field
Molecular QED of coherent and incoherent sum-frequency and second-harmonic generation in chiral liquids in the presence of a static electric field

Fischer, P., Salam, A.

MOLECULAR PHYSICS, 108(14):1857-1868, 2010 (article)

Abstract
Coherent second-order nonlinear optical processes are symmetry forbidden in centrosymmetric environments in the electric-dipole approximation. In liquids that contain chiral molecules, however, and which therefore lack mirror image symmetry, coherent sum-frequency generation is possible, whereas second-harmonic generation remains forbidden. Here we apply the theory of molecular quantum electrodynamics to the calculation of the matrix element, transition rate, and integrated signal intensity for sum-frequency and second-harmonic generation taking place in a chiral liquid in the presence and absence of a static electric field, to examine which coherent and incoherent processes exist in the electric-dipole approximation in liquids. Third- and fourth-order time-dependent perturbation theory is employed in combination with single-sided Feynman diagrams to evaluate two contributions arising from static field-free and field-induced processes. It is found that, in addition to the coherent term, an incoherent process exists for sum-frequency generation in liquids. Surprisingly, in the case of dc-field-induced second-harmonic generation, the incoherent contribution is found to always vanish for isotropic chiral liquids even though hyper-Rayleigh second-harmonic generation and electric-field-induced second-harmonic generation are both independently symmetry allowed in any liquid.

pf

DOI [BibTex]


Phantom Limb Pain Management Using Facial Expression Analysis, Biofeedback and Augmented Reality Interfacing
Phantom Limb Pain Management Using Facial Expression Analysis, Biofeedback and Augmented Reality Interfacing

Tzionas, D., Vrenas, K., Eleftheriadis, S., Georgoulis, S., Petrantonakis, P. C., Hadjileontiadis, L. J.

In Proceedings of the 3rd International Conferenceon Software Development for EnhancingAccessibility and Fighting Info-Exclusion, pages: 23-30, DSAI ’10, UTAD - Universidade de Trás-os-Montes e Alto Douro, 2010 (inproceedings)

Abstract
Post-amputation sensation often translates to the feeling of severe pain in the missing limb, referred to as phantom limb pain (PLP). A clear and rational treatment regimen is difficult to establish, as long as the underlying pathophysiology is not fully known. In this work, an innovative PLP management system is presented, as a module of an holistic computer-mediated pain management environment, namely Epione. The proposed Epione-PLP scheme is structured upon advanced facial expression analysis, used to form a dynamic pain meter, which, in turn, is used to trigger biofeedback and augmented reality-based PLP distraction scenarios. The latter incorporate a model of the missing limb for its visualization, in an effort to provide to the amputee the feeling of its existence and control, and, thus, maximize his/her PLP relief. The novel Epione-PLP management approach integrates edge-technology within the context of personalized health and it could be used to facilitate easing of PLP patients' suffering, provide efficient progress monitoring and contribute to the increase in their quality of life.

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Paper Project Page link (url) [BibTex]

Paper Project Page link (url) [BibTex]


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Flat dry elastomer adhesives as attachment materials for climbing robots

Unver, O., Sitti, M.

IEEE transactions on robotics, 26(1):131-141, IEEE, 2010 (article)

pi

[BibTex]

[BibTex]


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Adhesion recovery and passive peeling in a wall climbing robot using adhesives

Kute, C., Murphy, M. P., Mengüç, Y., Sitti, M.

In Robotics and Automation (ICRA), 2010 IEEE International Conference on, pages: 2797-2802, 2010 (inproceedings)

pi

[BibTex]

[BibTex]


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A Bayesian approach to nonlinear parameter identification for rigid-body dynamics

Ting, J., DSouza, A., Schaal, S.

Neural Networks, 2010, clmc (article)

Abstract
For complex robots such as humanoids, model-based control is highly beneficial for accurate tracking while keeping negative feedback gains low for compliance. However, in such multi degree-of-freedom lightweight systems, conventional identification of rigid body dynamics models using CAD data and actuator models is inaccurate due to unknown nonlinear robot dynamic effects. An alternative method is data-driven parameter estimation, but significant noise in measured and inferred variables affects it adversely. Moreover, standard estimation procedures may give physically inconsistent results due to unmodeled nonlinearities or insufficiently rich data. This paper addresses these problems, proposing a Bayesian system identification technique for linear or piecewise linear systems. Inspired by Factor Analysis regression, we develop a computationally efficient variational Bayesian regression algorithm that is robust to ill-conditioned data, automatically detects relevant features, and identifies input and output noise. We evaluate our approach on rigid body parameter estimation for various robotic systems, achieving an error of up to three times lower than other state-of-the-art machine learning methods.

am

link (url) [BibTex]


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A first optimal control solution for a complex, nonlinear, tendon driven neuromuscular finger model

Theodorou, E. A., Todorov, E., Valero-Cuevas, F.

Proceedings of the ASME 2010 Summer Bioengineering Conference August 30-September 2, 2010, Naples, Florida, USA, 2010, clmc (article)

Abstract
In this work we present the first constrained stochastic op- timal feedback controller applied to a fully nonlinear, tendon driven index finger model. Our model also takes into account an extensor mechanism, and muscle force-length and force-velocity properties. We show this feedback controller is robust to noise and perturbations to the dynamics, while successfully handling the nonlinearities and high dimensionality of the system. By ex- tending prior methods, we are able to approximate physiological realism by ensuring positivity of neural commands and tendon tensions at all timesthus can, for the first time, use the optimal control framework to predict biologically plausible tendon tensions for a nonlinear neuromuscular finger model. METHODS 1 Muscle Model The rigid-body triple pendulum finger model with slightly viscous joints is actuated by Hill-type muscle models. Joint torques are generated by the seven muscles of the index fin-

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PDF [BibTex]

PDF [BibTex]


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Are reaching movements planned in kinematic or dynamic coordinates?

Ellmer, A., Schaal, S.

In Abstracts of Neural Control of Movement Conference (NCM 2010), Naples, Florida, 2010, 2010, clmc (inproceedings)

Abstract
Whether human reaching movements are planned and optimized in kinematic (task space) or dynamic (joint or muscle space) coordinates is still an issue of debate. The first hypothesis implies that a planner produces a desired end-effector position at each point in time during the reaching movement, whereas the latter hypothesis includes the dynamics of the muscular-skeletal control system to produce a continuous end-effector trajectory. Previous work by Wolpert et al (1995) showed that when subjects were led to believe that their straight reaching paths corresponded to curved paths as shown on a computer screen, participants adapted the true path of their hand such that they would visually perceive a straight line in visual space, despite that they actually produced a curved path. These results were interpreted as supporting the stance that reaching trajectories are planned in kinematic coordinates. However, this experiment could only demonstrate that adaptation to altered paths, i.e. the position of the end-effector, did occur, but not that the precise timing of end-effector position was equally planned, i.e., the trajectory. Our current experiment aims at filling this gap by explicitly testing whether position over time, i.e. velocity, is a property of reaching movements that is planned in kinematic coordinates. In the current experiment, the velocity profiles of cursor movements corresponding to the participant's hand motions were skewed either to the left or to the right; the path itself was left unaltered. We developed an adaptation paradigm, where the skew of the velocity profile was introduced gradually and participants reported no awareness of any manipulation. Preliminary results indicate that the true hand motion of participants did not alter, i.e. there was no adaptation so as to counterbalance the introduced skew. However, for some participants, peak hand velocities were lowered for higher skews, which suggests that participants interpreted the manipulation as mere noise due to variance in their own movement. In summary, for a visuomotor transformation task, the hypothesis of a planned continuous end-effector trajectory predicts adaptation to a modified velocity profile. The current experiment found no systematic adaptation under such transformation, but did demonstrate an effect that is more in accordance that subjects could not perceive the manipulation and rather interpreted as an increase of noise.

am

[BibTex]

[BibTex]


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Combining depth and color cues for scale- and viewpoint-invariant object segmentation and recognition using Random Forests

Stueckler, J., Behnke, S.

In Proc. of the IEEE/RSJ Int. Conf. on Intelligent Robots and Systems (IROS), pages: 4566-4571, October 2010 (inproceedings)

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link (url) DOI [BibTex]

link (url) DOI [BibTex]


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Intuitive Multimodal Interaction for Domestic Service Robots

Nieuwenhuisen, M., Stueckler, J., Behnke, S.

In Proc. of the ISR/ROBOTIK, VDE Verlag, 2010 (inproceedings)

ev

link (url) [BibTex]

link (url) [BibTex]


 Automated Home-Cage Behavioral Phenotyping of Mice
Automated Home-Cage Behavioral Phenotyping of Mice

Jhuang, H., Garrote, E., Mutch, J., Poggio, T., Steele, A., Serre, T.

Nature Communications, Nature Communications, 2010 (article)

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software, demo pdf [BibTex]

software, demo pdf [BibTex]


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An automated action initiation system reveals behavioral deficits in MyosinVa deficient mice

Pandian, S., Edelman, N., Jhuang, H., Serre, T., Poggio, T., Constantine-Paton, M.

Society for Neuroscience, 2010 (conference)

ps

pdf [BibTex]

pdf [BibTex]


Dense Marker-less Three Dimensional Motion Capture
Dense Marker-less Three Dimensional Motion Capture

Soren Hauberg, Bente Rona Jensen, Morten Engell-Norregaard, Kenny Erleben, Kim S. Pedersen

In Virtual Vistas; Eleventh International Symposium on the 3D Analysis of Human Movement, 2010 (inproceedings)

ps

Conference site [BibTex]

Conference site [BibTex]


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Dzyaloshinskii-Moriya interactions in systems with fabrication induced strain gradients: ab-initio study

Beck, P., Fähnle, M

{Journal of Magnetism and Magnetic Materials}, 322, pages: 3701-3703, 2010 (article)

mms

DOI [BibTex]

DOI [BibTex]


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On the nature of displacement bursts during nanoindentation of ultrathin Ni films on sapphire

Rabkin, E., Deuschle, J. K., Baretzky, B.

{Acta Materialia}, 58, pages: 1589-1598, 2010 (article)

mms

DOI [BibTex]

DOI [BibTex]


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Nanospheres generate out-of-plane magnetization

Amaladass, E., Ludescher, B., Schütz, G., Tyliszczak, T., Lee, M., Eimüller, T.

{Journal of Applied Physics}, 107, 2010 (article)

mms

DOI [BibTex]

DOI [BibTex]


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Absence of element specific ferromagnetism in Co doped ZnO investigated by soft X-ray resonant reflectivity

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

In 200, Glasgow, Scotland, 2010 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


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Probing the local magnetization dynamics in large systems with spatial inhomogeneity

Li, J, Lee, M.-S., Amaladass, E., He, W., Eimüller, T.

In 200, Glasgow, Scotland, 2010 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


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Temperature dependence of the magnetic properties of L10-FePt nanostructures and films

Bublat, T., Goll, D.

{Journal of Applied Physics}, 108(11), 2010 (article)

mms

DOI [BibTex]

DOI [BibTex]


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Wetting of grain boundaries in Al by the solid Al3Mg2 phase

Straumal, B. B., Baretzky, B., Kogtenkova, O. A., Straumal, A. B., Sidorenko, A. S.

In 45, pages: 2057-2061, Athens, Greek, 2010 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


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Damping of near-adiabatic magnetization dynamics by excitations of electron-hole pairs

Seib, J., Steiauf, D., Fähnle, M.

In 200, Karlsruhe, Germany, 2010 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


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Magnetic properties of Fe nanoclusters on Cu(111) studied with X-ray magnetic circular dichroism

Fauth, K., Ballentine, G., Praetorius, C., Kleibert, A., Wilken, N., Voitkans, A., Meiwes-Broer, K.-H.

{Physica Status Solidi B}, 247(5):1170-1179, 2010 (article)

mms

DOI [BibTex]

DOI [BibTex]


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An experimental analysis of elliptical adhesive contact

Sümer, B., Onal, C. D., Aksak, B., Sitti, M.

Journal of Applied Physics, 107(11):113512, AIP, 2010 (article)

pi

Project Page [BibTex]

Project Page [BibTex]


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Comparison of linear and nonlinear buck converter models with varying compensator gain values for design optimization

Sattler, Michael, Lui, Yusi, Edrington, Chris S

In North American Power Symposium (NAPS), 2010, pages: 1-7, 2010 (inproceedings)

pi

[BibTex]

[BibTex]


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Optimality in Neuromuscular Systems

Theodorou, E. A., Valero-Cuevas, F.

In 32nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2010, clmc (inproceedings)

Abstract
Abstract? We provide an overview of optimal control meth- ods to nonlinear neuromuscular systems and discuss their lim- itations. Moreover we extend current optimal control methods to their application to neuromuscular models with realistically numerous musculotendons; as most prior work is limited to torque-driven systems. Recent work on computational motor control has explored the used of control theory and esti- mation as a conceptual tool to understand the underlying computational principles of neuromuscular systems. After all, successful biological systems regularly meet conditions for stability, robustness and performance for multiple classes of complex tasks. Among a variety of proposed control theory frameworks to explain this, stochastic optimal control has become a dominant framework to the point of being a standard computational technique to reproduce kinematic trajectories of reaching movements (see [12]) In particular, we demonstrate the application of optimal control to a neuromuscular model of the index finger with all seven musculotendons producing a tapping task. Our simu- lations include 1) a muscle model that includes force- length and force-velocity characteristics; 2) an anatomically plausible biomechanical model of the index finger that includes a tendi- nous network for the extensor mechanism and 3) a contact model that is based on a nonlinear spring-damper attached at the end effector of the index finger. We demonstrate that it is feasible to apply optimal control to systems with realistically large state vectors and conclude that, while optimal control is an adequate formalism to create computational models of neuro- musculoskeletal systems, there remain important challenges and limitations that need to be considered and overcome such as contact transitions, curse of dimensionality, and constraints on states and controls.

am

PDF [BibTex]

PDF [BibTex]


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Efficient learning and feature detection in high dimensional regression

Ting, J., D’Souza, A., Vijayakumar, S., Schaal, S.

Neural Computation, 22, pages: 831-886, 2010, clmc (article)

Abstract
We present a novel algorithm for efficient learning and feature selection in high- dimensional regression problems. We arrive at this model through a modification of the standard regression model, enabling us to derive a probabilistic version of the well-known statistical regression technique of backfitting. Using the Expectation- Maximization algorithm, along with variational approximation methods to overcome intractability, we extend our algorithm to include automatic relevance detection of the input features. This Variational Bayesian Least Squares (VBLS) approach retains its simplicity as a linear model, but offers a novel statistically robust â??black- boxâ? approach to generalized linear regression with high-dimensional inputs. It can be easily extended to nonlinear regression and classification problems. In particular, we derive the framework of sparse Bayesian learning, e.g., the Relevance Vector Machine, with VBLS at its core, offering significant computational and robustness advantages for this class of methods. We evaluate our algorithm on synthetic and neurophysiological data sets, as well as on standard regression and classification benchmark data sets, comparing it with other competitive statistical approaches and demonstrating its suitability as a drop-in replacement for other generalized linear regression techniques.

am

link (url) [BibTex]

link (url) [BibTex]


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Improving People Awareness of Service Robots by Semantic Scene Knowledge

Stueckler, J., Behnke, S.

In RobuCup, 6556, pages: 157-168, Lecture Notes in Computer Science, Springer, 2010 (inproceedings)

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link (url) [BibTex]

link (url) [BibTex]


Stick It! Articulated Tracking using Spatial Rigid Object Priors
Stick It! Articulated Tracking using Spatial Rigid Object Priors

Soren Hauberg, Kim S. Pedersen

In Computer Vision – ACCV 2010, 6494, pages: 758-769, Lecture Notes in Computer Science, (Editors: Kimmel, Ron and Klette, Reinhard and Sugimoto, Akihiro), Springer Berlin Heidelberg, 2010 (inproceedings)

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Publishers site Paper site Code PDF [BibTex]

Publishers site Paper site Code PDF [BibTex]


Gaussian-like Spatial Priors for Articulated Tracking
Gaussian-like Spatial Priors for Articulated Tracking

Soren Hauberg, Stefan Sommer, Kim S. Pedersen

In Computer Vision – ECCV 2010, 6311, pages: 425-437, Lecture Notes in Computer Science, (Editors: Daniilidis, Kostas and Maragos, Petros and Paragios, Nikos), Springer Berlin Heidelberg, 2010 (inproceedings)

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Publishers site Paper site Code PDF [BibTex]

Publishers site Paper site Code PDF [BibTex]


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Reach to grasp actions in rhesus macaques: Dimensionality reduction of hand, wrist, and upper arm motor subspaces using principal component analysis

Vargas-Irwin, C., Franquemont, L., Shakhnarovich, G., Yadollahpour, P., Black, M., Donoghue, J.

2010 Abstract Viewer and Itinerary Planner, Society for Neuroscience, 2010, Online (conference)

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[BibTex]

[BibTex]


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Nanoscale imaging using deep ultraviolet digital holographic microscopy

Faridian, A., Hopp, D., Pedrini, G., Eigenthaler, U., Hirscher, M., Osten, W.

{Optics Express}, 18(13):14159-14164, 2010 (article)

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DOI [BibTex]

DOI [BibTex]


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Metal-organic frameworks for hydrogen storage

Hirscher, M., Panella, B., Schmitz, B.

{Microporous and Mesoporous Materials}, 129, pages: 335-339, 2010 (article)

mms

DOI [BibTex]

DOI [BibTex]


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Samarium-cobalt 2:17 magnets: analysis of the coercive field of Sm2(CoFeCuZr)17 high-temperature permanent magnets

Goll, D., Stadelmaier, H. H., Kronmüller, H.

{Scripta Materialia}, 63, pages: 243-245, 2010 (article)

mms

DOI [BibTex]

DOI [BibTex]


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Low-temperature growth of silicon nanotubes and nanowires on amorphous substrates

Mbenkum, B. N., Schneider, A. S., Schütz, G., Xu, C., Richter, G., van Aken, P. A., Majer, G., Spatz, J. P.

{ACS Nano}, 4(4):1805-1812, 2010 (article)

mms

DOI [BibTex]

DOI [BibTex]