Header logo is


2018


no image
Kernel Recursive ABC: Point Estimation with Intractable Likelihood

Kajihara, T., Kanagawa, M., Yamazaki, K., Fukumizu, K.

Proceedings of the 35th International Conference on Machine Learning, pages: 2405-2414, PMLR, July 2018 (conference)

Abstract
We propose a novel approach to parameter estimation for simulator-based statistical models with intractable likelihood. Our proposed method involves recursive application of kernel ABC and kernel herding to the same observed data. We provide a theoretical explanation regarding why the approach works, showing (for the population setting) that, under a certain assumption, point estimates obtained with this method converge to the true parameter, as recursion proceeds. We have conducted a variety of numerical experiments, including parameter estimation for a real-world pedestrian flow simulator, and show that in most cases our method outperforms existing approaches.

pn

Paper [BibTex]

2018


Paper [BibTex]


no image
Travelling Ultrasonic Wave Enhances Keyclick Sensation

Gueorguiev, D., Kaci, A., Amberg, M., Giraud, F., Lemaire-Semail, B.

In Haptics: Science, Technology, and Applications, pages: 302-312, Springer International Publishing, Cham, 2018 (inproceedings)

Abstract
A realistic keyclick sensation is a serious challenge for haptic feedback since vibrotactile rendering faces the limitation of the absence of contact force as experienced on physical buttons. It has been shown that creating a keyclick sensation is possible with stepwise ultrasonic friction modulation. However, the intensity of the sensation is limited by the impedance of the fingertip and by the absence of a lateral force component external to the finger. In our study, we compare this technique to rendering with an ultrasonic travelling wave, which exerts a lateral force on the fingertip. For both techniques, participants were asked to report the detection (or not) of a keyclick during a forced choice one interval procedure. In experiment 1, participants could press the surface as many time as they wanted for a given trial. In experiment 2, they were constrained to press only once. The results show a lower perceptual threshold for travelling waves. Moreover, participants pressed less times per trial and exerted smaller normal force on the surface. The subjective quality of the sensation was found similar for both techniques. In general, haptic feedback based on travelling ultrasonic waves is promising for applications without lateral motion of the finger.

hi

[BibTex]

[BibTex]


Dissecting Adam: The Sign, Magnitude and Variance of Stochastic Gradients
Dissecting Adam: The Sign, Magnitude and Variance of Stochastic Gradients

Balles, L., Hennig, P.

In Proceedings of the 35th International Conference on Machine Learning (ICML), 2018 (inproceedings) Accepted

Abstract
The ADAM optimizer is exceedingly popular in the deep learning community. Often it works very well, sometimes it doesn't. Why? We interpret ADAM as a combination of two aspects: for each weight, the update direction is determined by the sign of stochastic gradients, whereas the update magnitude is determined by an estimate of their relative variance. We disentangle these two aspects and analyze them in isolation, gaining insight into the mechanisms underlying ADAM. This analysis also extends recent results on adverse effects of ADAM on generalization, isolating the sign aspect as the problematic one. Transferring the variance adaptation to SGD gives rise to a novel method, completing the practitioner's toolbox for problems where ADAM fails.

pn

link (url) Project Page [BibTex]

link (url) Project Page [BibTex]


no image
Exploring Fingers’ Limitation of Texture Density Perception on Ultrasonic Haptic Displays

Kalantari, F., Gueorguiev, D., Lank, E., Bremard, N., Grisoni, L.

In Haptics: Science, Technology, and Applications, pages: 354-365, Springer International Publishing, Cham, 2018 (inproceedings)

Abstract
Recent research in haptic feedback is motivated by the crucial role that tactile perception plays in everyday touch interactions. In this paper, we describe psychophysical experiments to investigate the perceptual threshold of individual fingers on both the right and left hand of right-handed participants using active dynamic touch for spatial period discrimination of both sinusoidal and square-wave gratings on ultrasonic haptic touchscreens. Both one-finger and multi-finger touch were studied and compared. Our results indicate that users' finger identity (index finger, middle finger, etc.) significantly affect the perception of both gratings in the case of one-finger exploration. We show that index finger and thumb are the most sensitive in all conditions whereas little finger followed by ring are the least sensitive for haptic perception. For multi-finger exploration, the right hand was found to be more sensitive than the left hand for both gratings. Our findings also demonstrate similar perception sensitivity between multi-finger exploration and the index finger of users' right hands (i.e. dominant hand in our study), while significant difference was found between single and multi-finger perception sensitivity for the left hand.

hi

[BibTex]

[BibTex]


no image
Direct observations of sub-100 nm spin wave propagation in magnonic wave-guides

Träger, N., Gruszecki, P., Lisiecki, F., Förster, J., Weigand, M., Kuswik, P., Dubowik, J., Schütz, G., Krawczyk, M., Gräfe, J.

In 2018 IEEE International Magnetics Conference (INTERMAG 2018), IEEE, Singapore, 2018 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


no image
Interpreting FORC diagrams beyond the Preisach model: an experimental permalloy micro array investigation

Gross, F., Ilse, S., Schütz, G., Gräfe, J., Goering, E.

In 2018 IEEE International Magnetics Conference (INTERMAG 2018), IEEE, Singapore, 2018 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]

2015


Automatic LQR Tuning Based on Gaussian Process Optimization: Early Experimental Results
Automatic LQR Tuning Based on Gaussian Process Optimization: Early Experimental Results

Marco, A., Hennig, P., Bohg, J., Schaal, S., Trimpe, S.

Machine Learning in Planning and Control of Robot Motion Workshop at the IEEE/RSJ International Conference on Intelligent Robots and Systems (iROS), pages: , , Machine Learning in Planning and Control of Robot Motion Workshop, October 2015 (conference)

Abstract
This paper proposes an automatic controller tuning framework based on linear optimal control combined with Bayesian optimization. With this framework, an initial set of controller gains is automatically improved according to a pre-defined performance objective evaluated from experimental data. The underlying Bayesian optimization algorithm is Entropy Search, which represents the latent objective as a Gaussian process and constructs an explicit belief over the location of the objective minimum. This is used to maximize the information gain from each experimental evaluation. Thus, this framework shall yield improved controllers with fewer evaluations compared to alternative approaches. A seven-degree-of-freedom robot arm balancing an inverted pole is used as the experimental demonstrator. Preliminary results of a low-dimensional tuning problem highlight the method’s potential for automatic controller tuning on robotic platforms.

am ei ics pn

PDF DOI Project Page [BibTex]

2015


PDF DOI Project Page [BibTex]


no image
Toward a large-scale visuo-haptic dataset for robotic learning

Burka, A., Hu, S., Krishnan, S., Kuchenbecker, K. J., Hendricks, L. A., Gao, Y., Darrell, T.

In Proc. CVPR Workshop on the Future of Datasets in Vision, 2015 (inproceedings)

hi

Project Page [BibTex]

Project Page [BibTex]


no image
Detecting Lumps in Simulated Tissue via Palpation with a BioTac

Hui, J., Block, A., Kuchenbecker, K. J.

In Proc. IEEE World Haptics Conference, 2015, Work-in-progress paper. Poster presentation given by Hui (inproceedings)

hi

[BibTex]

[BibTex]


no image
Analysis of the Instrument Vibrations and Contact Forces Caused by an Expert Robotic Surgeon Doing FRS Tasks

Brown, J. D., O’Brien, C., Miyasaka, K., Dumon, K. R., Kuchenbecker, K. J.

In Proc. Hamlyn Symposium on Medical Robotics, pages: 75-76, London, England, June 2015, Poster presentation given by Brown (inproceedings)

hi

[BibTex]

[BibTex]


no image
Should Haptic Texture Vibrations Respond to User Force and Speed?

Culbertson, H., Kuchenbecker, K. J.

In IEEE World Haptics Conference, pages: 106 - 112, Evanston, Illinois, USA, June 2015, Oral presentation given by Culbertson (inproceedings)

hi

[BibTex]

[BibTex]


no image
Enabling the Baxter Robot to Play Hand-Clapping Games

Fitter, N. T., Neuburger, M., Kuchenbecker, K. J.

In Proc. IEEE World Haptics Conference, June 2015, Work-in-progress paper. Poster presentation given by Fitter (inproceedings)

hi

[BibTex]

[BibTex]


no image
Using IMU Data to Teach a Robot Hand-Clapping Games

Fitter, N. T., Kuchenbecker, K. J.

In Proc. IEEE Haptics Symposium, pages: 353-355, April 2015, Work-in-progress paper. Poster presentation given by Fitter (inproceedings)

hi

[BibTex]

[BibTex]


no image
Haptic Feedback in Transoral Robotic Surgery: A Feasibility Study

Bur, A. M., Gomez, E. D., Rassekh, C. H., Newman, J. G., Weinstein, G. S., Kuchenbecker, K. J.

In Proc. Annual Meeting of the Triological Society at COSM, April 2015, Poster presentation given by Bur (inproceedings)

hi

[BibTex]

[BibTex]


no image
Design and Validation of a Practical Simulator for Transoral Robotic Surgery

Bur, A. M., Gomez, E. D., Chalian, A. A., Newman, J. G., Weinstein, G. S., Kuchenbecker, K. J.

In Proc. Society for Robotic Surgery Annual Meeting: Transoral Program, (T8), February 2015, Oral presentation given by Bur (inproceedings)

hi

[BibTex]

[BibTex]


no image
Inference of Cause and Effect with Unsupervised Inverse Regression

Sgouritsa, E., Janzing, D., Hennig, P., Schölkopf, B.

In Proceedings of the 18th International Conference on Artificial Intelligence and Statistics, 38, pages: 847-855, JMLR Workshop and Conference Proceedings, (Editors: Lebanon, G. and Vishwanathan, S.V.N.), JMLR.org, AISTATS, 2015 (inproceedings)

ei pn

Web PDF [BibTex]

Web PDF [BibTex]


Probabilistic Line Searches for Stochastic Optimization
Probabilistic Line Searches for Stochastic Optimization

Mahsereci, M., Hennig, P.

In Advances in Neural Information Processing Systems 28, pages: 181-189, (Editors: C. Cortes, N.D. Lawrence, D.D. Lee, M. Sugiyama and R. Garnett), Curran Associates, Inc., 29th Annual Conference on Neural Information Processing Systems (NIPS), 2015 (inproceedings)

Abstract
In deterministic optimization, line searches are a standard tool ensuring stability and efficiency. Where only stochastic gradients are available, no direct equivalent has so far been formulated, because uncertain gradients do not allow for a strict sequence of decisions collapsing the search space. We construct a probabilistic line search by combining the structure of existing deterministic methods with notions from Bayesian optimization. Our method retains a Gaussian process surrogate of the univariate optimization objective, and uses a probabilistic belief over the Wolfe conditions to monitor the descent. The algorithm has very low computational cost, and no user-controlled parameters. Experiments show that it effectively removes the need to define a learning rate for stochastic gradient descent. [You can find the matlab research code under `attachments' below. The zip-file contains a minimal working example. The docstring in probLineSearch.m contains additional information. A more polished implementation in C++ will be published here at a later point. For comments and questions about the code please write to mmahsereci@tue.mpg.de.]

ei pn

Matlab research code link (url) [BibTex]

Matlab research code link (url) [BibTex]


no image
A Random Riemannian Metric for Probabilistic Shortest-Path Tractography

Hauberg, S., Schober, M., Liptrot, M., Hennig, P., Feragen, A.

In 18th International Conference on Medical Image Computing and Computer Assisted Intervention, 9349, pages: 597-604, Lecture Notes in Computer Science, MICCAI, 2015 (inproceedings)

ei pn

PDF DOI [BibTex]

PDF DOI [BibTex]


no image
Combined FORC and x-ray microscopy study of magnetisation reversal in antidot lattices

Gräfe, J., Haering, F., Stahl, C., Weigand, M., Skripnik, M., Nowak, U., Ziemann, P., Wiedwald, U., Schütz, G., Goering, E.

In IEEE International Magnetics Conference (INTERMAG 2015), IEEE, Beijing, China, 2015 (inproceedings)

mms

DOI Project Page Project Page [BibTex]

DOI Project Page Project Page [BibTex]


no image
Local control of domain wall dynamics in ferromagnetic rings

Richter, K., Mawass, M., Krone, A., Krüger, B., Weigand, M., Stoll, H., Schütz, G., Kläui, M.

In IEEE International Magnetics Conference (INTERMAG 2015), IEEE, Beijing, China, 2015 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


no image
Ultrafast demagnetization after laser pulse irradiation in Ni: Ab-initio electron-phonon scattering and phase space calculations

Illg, C., Haag, M., Fähnle, M.

In Ultrafast Magnetism I. Proceedings of the International Conference UMC 2013, 159, pages: 131-133, Springer Proceedings in Physics, Springer, Strasbourg, 2015 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


no image
Automotive domain wall propagation in ferromagnetic rings

Richter, K., Mawass, M., Krone, A., Krüger, B., Weigand, M., Schütz, G., Stoll, H., Kläui, M.

In IEEE International Magnetics Conference (INTERMAG 2015), IEEE, Beijing, China, 2015 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


no image
The third dimension: Vortex core reversal by interaction with \textquotesingleflexure modes’

Noske, M., Stoll, H., Fähnle, M., Weigand, M., Dieterle, G., Förster, J., Gangwar, A., Slavin, A., Back, C. H., Schütz, G.

In IEEE International Magnetics Conference (INTERMAG 2015), IEEE, Beijing, China, 2015 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]


no image
Skyrmions at room temperature in magnetic multilayers

Moreau-Luchaire, C., Reyren, N., Moutafis, C., Sampaio, J., Van Horne, N., Vaz, C. A., Warnicke, P., Garcia, K., Weigand, M., Bouzehouane, K., Deranlot, C., George, J., Raabe, J., Cros, V., Fert, A.

In IEEE International Magnetics Conference (INTERMAG 2015), IEEE, Beijing, China, 2015 (inproceedings)

mms

DOI [BibTex]

DOI [BibTex]

2009


no image
Image-Enabled Force Feedback for Robotic Teleoperation of a Flexible Tool

Lindsey, Q., Tenenholtz, N., Lee, D. I., Kuchenbecker, K. J.

In Proc. IASTED International Conference on Robotics and Applications, pages: 224-233, Boston, Massachusetts, November 2009, Oral presentation given by Lindsey (inproceedings)

hi

[BibTex]

2009


[BibTex]


no image
GPU Methods for Real-Time Haptic Interaction with 3D Fluids

Yang, M., Lu, J., Safonova, A., Kuchenbecker, K. J.

In Proc. IEEE International Workshop on Haptic Audio-Visual Environments and Games, pages: 24-29, Lecco, Italy, November 2009, Oral presentation given by Kuchenbecker (inproceedings)

hi

[BibTex]

[BibTex]


no image
The AirWand: Design and Characterization of a Large-Workspace Haptic Device

Romano, J. M., Kuchenbecker, K. J.

In Proc. IEEE International Conference on Robotics and Automation, pages: 1461-1466, Kobe, Japan, May 2009, Oral presentation given by \uline{Romano} (inproceedings)

hi

[BibTex]

[BibTex]


no image
Stiffness Discrimination with Visual and Proprioceptive Cues

Gurari, N., Kuchenbecker, K. J., Okamura, A. M.

In Proc. IEEE World Haptics Conference, pages: 121-126, Salt Lake City, Utah, USA, March 2009, Poster presentation given by Gurari (inproceedings)

hi

[BibTex]

[BibTex]


no image
Toward Tactilely Transparent Gloves: Collocated Slip Sensing and Vibrotactile Actuation

Romano, J. M., Gray, S. R., Jacobs, N. T., Kuchenbecker, K. J.

In Proc. IEEE World Haptics Conference, pages: 279-284, Salt Lake City, Utah, USA, March 2009, Poster presentation given by Romano, Gray, and Jacobs (inproceedings)

hi

[BibTex]

[BibTex]


no image
A High-Fidelity Ungrounded Torque Feedback Device: The iTorqU 2.0

Winfree, K. N., Gewirtz, J., Mather, T., Fiene, J., Kuchenbecker, K. J.

In Proc. IEEE World Haptics Conference, pages: 261-266, Salt Lake City, Utah, USA, March 2009, Poster presentation given by Winfree and Gewirtz (inproceedings)

hi

[BibTex]

[BibTex]


no image
Real-Time Graphic and Haptic Simulation of Deformable Tissue Puncture

Romano, J. M., Safonova, A., Kuchenbecker, K. J.

In Proc. Medicine Meets Virtual Reality, Long Beach, California, USA, January 2009, Poster presentation given by Romano (inproceedings)

hi

[BibTex]

[BibTex]


no image
Haptic Display of Realistic Tool Contact Via Dynamically Compensated Control of a Dedicated Actuator

McMahan, W., Kuchenbecker, K. J.

In Proc. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages: 3171-3177, St. Louis, Missouri, USA, 2009, Oral presentation given by McMahan (inproceedings)

hi

[BibTex]

[BibTex]