Publications | Max Planck Institute for Intelligent Systems

Babbar, R., Schölkopf, B.

Data scarcity, robustness and extreme multi-label classification

Machine Learning, 108(8):1329-1351, September 2019, Special Issue of the ECML PKDD 2019 Journal Track (article)

ei Babbar, R., Schölkopf, B. Data scarcity, robustness and extreme multi-label classification Machine Learning, 108(8):1329-1351, September 2019, Special Issue of the ECML PKDD 2019 Journal Track (article)

Programmable Collective Behavior in Dynamically Self‐Assembled Mobile Microrobotic Swarms

Berk Yigit, Y. A. M. S.

Advanced Science, 6, March 2019 (article)

pi Berk Yigit, Y. A. M. S. Programmable Collective Behavior in Dynamically Self‐Assembled Mobile Microrobotic Swarms Advanced Science, 6, March 2019 (article)

X-ray Optics Fabrication Using Unorthodox Approaches

Sanli, U., Baluktsian, M., Ceylan, H., Sitti, M., Weigand, M., Schütz, G., Keskinbora, K.

Bulletin of the American Physical Society, APS, 2019 (article)

mms pi

mms pi Sanli, U., Baluktsian, M., Ceylan, H., Sitti, M., Weigand, M., Schütz, G., Keskinbora, K. X-ray Optics Fabrication Using Unorthodox Approaches Bulletin of the American Physical Society, APS, 2019 (article)

A 32-channel multi-coil setup optimized for human brain shimming at 9.4T

Aghaeifar, A., Zhou, J., Heule, R., Tabibian, B., Schölkopf, B., Jia, F., Zaitsev, M., Scheffler, K.

Magnetic Resonance in Medicine, 2019, (Early View) (article)

ei Aghaeifar, A., Zhou, J., Heule, R., Tabibian, B., Schölkopf, B., Jia, F., Zaitsev, M., Scheffler, K. A 32-channel multi-coil setup optimized for human brain shimming at 9.4T Magnetic Resonance in Medicine, 2019, (Early View) (article)

Temperature Gradients Drive Bulk Flow Within Microchannel Lined by Fluid–Fluid Interfaces

Amador, G. J., Ren, Z., Tabak, A. F., Alapan, Y., Yasa, O., Sitti, M.

Small, 15, Wiley Online Library, 2019 (article)

pi Amador, G. J., Ren, Z., Tabak, A. F., Alapan, Y., Yasa, O., Sitti, M. Temperature Gradients Drive Bulk Flow Within Microchannel Lined by Fluid–Fluid Interfaces Small, 15, Wiley Online Library, 2019 (article)

Microrobotics and Microorganisms: Biohybrid Autonomous Cellular Robots

Alapan, Y., Yasa, O., Yigit, B., Yasa, I. C., Erkoc, P., Sitti, M.

Annual Review of Control, Robotics, and Autonomous Systems, 2019 (article)

pi Alapan, Y., Yasa, O., Yigit, B., Yasa, I. C., Erkoc, P., Sitti, M. Microrobotics and Microorganisms: Biohybrid Autonomous Cellular Robots Annual Review of Control, Robotics, and Autonomous Systems, 2019 (article)

Woodward, M. A., Sitti, M.

Tailored Magnetic Springs for Shape-Memory Alloy Actuated Mechanisms in Miniature Robots

IEEE Transactions on Robotics, 35, 2019 (article)

Abstract

Animals can incorporate large numbers of actuators because of the characteristics of muscles; whereas, robots cannot, as typical motors tend to be large, heavy, and inefficient. However, shape-memory alloys (SMA), materials that contract during heating because of change in their crystal structure, provide another option. SMA, though, is unidirectional and therefore requires an additional force to reset (extend) the actuator, which is typically provided by springs or antagonistic actuation. These strategies, however, tend to limit the actuator's work output and functionality as their force-displacement relationships typically produce increasing resistive force with limited variability. In contrast, magnetic springs-composed of permanent magnets, where the interaction force between magnets mimics a spring force-have much more variable force-displacement relationships and scale well with SMA. However, as of yet, no method for designing magnetic springs for SMA-actuators has been demonstrated. Therefore, in this paper, we present a new methodology to tailor magnetic springs to the characteristics of these actuators, with experimental results both for the device and robot-integrated SMA-actuators. We found magnetic building blocks, based on sets of permanent magnets, which are well-suited to SMAs and have the potential to incorporate features such as holding force, state transitioning, friction minimization, auto-alignment, and self-mounting. We show magnetic springs that vary by more than 3 N in 750 $\mu$m and two SMA-actuated devices that allow the MultiMo-Bat to reach heights of up to 4.5 m without, and 3.6 m with, integrated gliding airfoils. Our results demonstrate the potential of this methodology to add previously impossible functionality to smart material actuators. We anticipate this methodology will inspire broader consideration of the use of magnetic springs in miniature robots and further study of the potential of tailored magnetic springs throughout mechanical systems.

pi Woodward, M. A., Sitti, M. Tailored Magnetic Springs for Shape-Memory Alloy Actuated Mechanisms in Miniature Robots IEEE Transactions on Robotics, 35, 2019 (article)

Magnetically Actuated Soft Capsule Endoscope for Fine-Needle Biopsy

Son, D., Gilbert, H., Sitti, M.

Soft robotics, Mary Ann Liebert, Inc., publishers 140 Huguenot Street, 3rd Floor New …, 2019 (article)

pi Son, D., Gilbert, H., Sitti, M. Magnetically Actuated Soft Capsule Endoscope for Fine-Needle Biopsy Soft robotics, Mary Ann Liebert, Inc., publishers 140 Huguenot Street, 3rd Floor New …, 2019 (article)

Thrust and Hydrodynamic Efficiency of the Bundled Flagella

Danis, U., Rasooli, R., Chen, C., Dur, O., Sitti, M., Pekkan, K.

Micromachines, 10, 2019 (article)

pi Danis, U., Rasooli, R., Chen, C., Dur, O., Sitti, M., Pekkan, K. Thrust and Hydrodynamic Efficiency of the Bundled Flagella Micromachines, 10, 2019 (article)

DOI Project Page Project Page [BibTex]

Multidimensional Contrast Limited Adaptive Histogram Equalization

Stimper, V., Bauer, S., Ernstorfer, R., Schölkopf, B., Xian, R. P.

IEEE Access, 7, pages: 165437-165447, 2019 (article)

arXiv link (url) DOI [BibTex]

ei Stimper, V., Bauer, S., Ernstorfer, R., Schölkopf, B., Xian, R. P. Multidimensional Contrast Limited Adaptive Histogram Equalization IEEE Access, 7, pages: 165437-165447, 2019 (article)

arXiv link (url) DOI [BibTex]

Enhancing Human Learning via Spaced Repetition Optimization

Tabibian, B., Upadhyay, U., De, A., Zarezade, A., Schölkopf, B., Gomez Rodriguez, M.

Proceedings of the National Academy of Sciences, 2019, PNAS published ahead of print January 22, 2019 (article)

ei Tabibian, B., Upadhyay, U., De, A., Zarezade, A., Schölkopf, B., Gomez Rodriguez, M. Enhancing Human Learning via Spaced Repetition Optimization Proceedings of the National Academy of Sciences, 2019, PNAS published ahead of print January 22, 2019 (article)

DOI Project Page Project Page [BibTex]

Learning to Control Highly Accelerated Ballistic Movements on Muscular Robots

Büchler, D., Calandra, R., Peters, J.

2019 (article) Submitted

Abstract

High-speed and high-acceleration movements are inherently hard to control. Applying learning to the control of such motions on anthropomorphic robot arms can improve the accuracy of the control but might damage the system. The inherent exploration of learning approaches can lead to instabilities and the robot reaching joint limits at high speeds. Having hardware that enables safe exploration of high-speed and high-acceleration movements is therefore desirable. To address this issue, we propose to use robots actuated by Pneumatic Artificial Muscles (PAMs). In this paper, we present a four degrees of freedom (DoFs) robot arm that reaches high joint angle accelerations of up to 28000 °/s^2 while avoiding dangerous joint limits thanks to the antagonistic actuation and limits on the air pressure ranges. With this robot arm, we are able to tune control parameters using Bayesian optimization directly on the hardware without additional safety considerations. The achieved tracking performance on a fast trajectory exceeds previous results on comparable PAM-driven robots. We also show that our system can be controlled well on slow trajectories with PID controllers due to careful construction considerations such as minimal bending of cables, lightweight kinematics and minimal contact between PAMs and PAMs with the links. Finally, we propose a novel technique to control the the co-contraction of antagonistic muscle pairs. Experimental results illustrate that choosing the optimal co-contraction level is vital to reach better tracking performance. Through the use of PAM-driven robots and learning, we do a small step towards the future development of robots capable of more human-like motions.

Arxiv Video [BibTex]

ei Büchler, D., Calandra, R., Peters, J. Learning to Control Highly Accelerated Ballistic Movements on Muscular Robots 2019 (article) Submitted

Arxiv Video [BibTex]

3D-Printed Biodegradable Microswimmer for Theranostic Cargo Delivery and Release

Ceylan, H., Yasa, I. C., Yasa, O., Tabak, A. F., Giltinan, J., Sitti, M.

ACS Nano, ACS Publications, 2019 (article)

pi Ceylan, H., Yasa, I. C., Yasa, O., Tabak, A. F., Giltinan, J., Sitti, M. 3D-Printed Biodegradable Microswimmer for Theranostic Cargo Delivery and Release ACS Nano, ACS Publications, 2019 (article)

The near and far of a pair of magnetic capillary disks

Koens, L., Wang, W., Sitti, M., Lauga, E.

Soft Matter, 2019 (article)

pi Koens, L., Wang, W., Sitti, M., Lauga, E. The near and far of a pair of magnetic capillary disks Soft Matter, 2019 (article)

Multifarious Transit Gates for Programmable Delivery of Bio‐functionalized Matters

Hu, X., Torati, S. R., Kim, H., Yoon, J., Lim, B., Kim, K., Sitti, M., Kim, C.

Small, Wiley Online Library, 2019 (article)

pi Hu, X., Torati, S. R., Kim, H., Yoon, J., Lim, B., Kim, K., Sitti, M., Kim, C. Multifarious Transit Gates for Programmable Delivery of Bio‐functionalized Matters Small, Wiley Online Library, 2019 (article)

Precise Control of Lyotropic Chromonic Liquid Crystals Alignment through Surface Topography

Guo, Y., Shahsavan, H., Davidson, Z., Sitti, M.

ACS applied materials \& interfaces, ACS Publications, 2019 (article)

pi Guo, Y., Shahsavan, H., Davidson, Z., Sitti, M. Precise Control of Lyotropic Chromonic Liquid Crystals Alignment through Surface Topography ACS applied materials \& interfaces, ACS Publications, 2019 (article)

Multi-functional soft-bodied jellyfish-like swimming

Ren, Z., Hu, W., Dong, X., Sitti, M.

Nature communications, 10, 2019 (article)

pi Ren, Z., Hu, W., Dong, X., Sitti, M. Multi-functional soft-bodied jellyfish-like swimming Nature communications, 10, 2019 (article)

Welcome to Progress in Biomedical Engineering

Sitti, M.

Progress in Biomedical Engineering, 1, IOP Publishing, 2019 (article)

pi Sitti, M. Welcome to Progress in Biomedical Engineering Progress in Biomedical Engineering, 1, IOP Publishing, 2019 (article)

Inferring causation from time series with perspectives in Earth system sciences

Runge, J., Bathiany, S., Bollt, E., Camps-Valls, G., Coumou, D., Deyle, E., Glymour, C., Kretschmer, M., Mahecha, M., van Nes, E., Peters, J., Quax, R., Reichstein, M., Scheffer, M. S. B., Spirtes, P., Sugihara, G., Sun, J., Zhang, K., Zscheischler, J.

Nature Communications, 2019 (article) In revision

ei Runge, J., Bathiany, S., Bollt, E., Camps-Valls, G., Coumou, D., Deyle, E., Glymour, C., Kretschmer, M., Mahecha, M., van Nes, E., Peters, J., Quax, R., Reichstein, M., Scheffer, M. S. B., Spirtes, P., Sugihara, G., Sun, J., Zhang, K., Zscheischler, J. Inferring causation from time series with perspectives in Earth system sciences Nature Communications, 2019 (article) In revision

Mechanics of a pressure-controlled adhesive membrane for soft robotic gripping on curved surfaces

Song, S., Drotlef, D., Paik, J., Majidi, C., Sitti, M.

Extreme Mechanics Letters, Elsevier, 2019 (article)

pi Song, S., Drotlef, D., Paik, J., Majidi, C., Sitti, M. Mechanics of a pressure-controlled adhesive membrane for soft robotic gripping on curved surfaces Extreme Mechanics Letters, Elsevier, 2019 (article)

Graphene oxide synergistically enhances antibiotic efficacy in Vancomycin resistance Staphylococcus aureus

Singh, V., Kumar, V., Kashyap, S., Singh, A. V., Kishore, V., Sitti, M., Saxena, P. S., Srivastava, A.

ACS Applied Bio Materials, ACS Publications, 2019 (article)

pi Singh, V., Kumar, V., Kashyap, S., Singh, A. V., Kishore, V., Sitti, M., Saxena, P. S., Srivastava, A. Graphene oxide synergistically enhances antibiotic efficacy in Vancomycin resistance Staphylococcus aureus ACS Applied Bio Materials, ACS Publications, 2019 (article)

Review of emerging concepts in nanotoxicology: opportunities and challenges for safer nanomaterial design

Singh, A. V., Laux, P., Luch, A., Sudrik, C., Wiehr, S., Wild, A., Santamauro, G., Bill, J., Sitti, M.

Toxicology Mechanisms and Methods, 2019 (article)

pi Singh, A. V., Laux, P., Luch, A., Sudrik, C., Wiehr, S., Wild, A., Santamauro, G., Bill, J., Sitti, M. Review of emerging concepts in nanotoxicology: opportunities and challenges for safer nanomaterial design Toxicology Mechanisms and Methods, 2019 (article)

Hakan Ceylan, I. C. Y. U. K. W. H. M. S.

Translational prospects of untethered medical microrobots

Progress in Biomedical Engineering, 1, 2019 (article)

pi Hakan Ceylan, I. C. Y. U. K. W. H. M. S. Translational prospects of untethered medical microrobots Progress in Biomedical Engineering, 1, 2019 (article)

Multifunctional magnetic hairbot for untethered osteogenesis, ultrasound contrast imaging and drug delivery

Singh, A. V., Ansari, M. H. D., Dayan, C. B., Giltinan, J., Wang, S., Yu, Y., Kishore, V., Laux, P., Luch, A., Sitti, M.

Biomaterials, 219, Elsevier, 2019 (article)

pi Singh, A. V., Ansari, M. H. D., Dayan, C. B., Giltinan, J., Wang, S., Yu, Y., Kishore, V., Laux, P., Luch, A., Sitti, M. Multifunctional magnetic hairbot for untethered osteogenesis, ultrasound contrast imaging and drug delivery Biomaterials, 219, Elsevier, 2019 (article)

Pena-Francesch, A., Giltinan, J., Sitti, M.

Multifunctional and biodegradable self-propelled protein motors

Nature communications, 10, Nature Publishing Group, 2019 (article)

pi Pena-Francesch, A., Giltinan, J., Sitti, M. Multifunctional and biodegradable self-propelled protein motors Nature communications, 10, Nature Publishing Group, 2019 (article)

Cohesive self-organization of mobile microrobotic swarms

Yigit, B., Alapan, Y., Sitti, M.

arXiv preprint arXiv:1907.05856, 2019 (article)

pi Yigit, B., Alapan, Y., Sitti, M. Cohesive self-organization of mobile microrobotic swarms arXiv preprint arXiv:1907.05856, 2019 (article)

Kübler, J. M., Muandet, K., Schölkopf, B.

Quantum mean embedding of probability distributions

Physical Review Research, 1(3):033159, American Physical Society, 2019 (article)

ei Kübler, J. M., Muandet, K., Schölkopf, B. Quantum mean embedding of probability distributions Physical Review Research, 1(3):033159, American Physical Society, 2019 (article)

Mobile microrobots for active therapeutic delivery

Erkoc, P., Yasa, I. C., Ceylan, H., Yasa, O., Alapan, Y., Sitti, M.

Advanced Therapeutics, Wiley Online Library, 2019 (article)

pi Erkoc, P., Yasa, I. C., Ceylan, H., Yasa, O., Alapan, Y., Sitti, M. Mobile microrobots for active therapeutic delivery Advanced Therapeutics, Wiley Online Library, 2019 (article)

Shape-encoded dynamic assembly of mobile micromachines

Alapan, Y., Yigit, B., Beker, O., Demirörs, A. F., Sitti, M.

Nature, 18, 2019 (article)

pi Alapan, Y., Yigit, B., Beker, O., Demirörs, A. F., Sitti, M. Shape-encoded dynamic assembly of mobile micromachines Nature, 18, 2019 (article)

Microfluidics Integrated Lithography‐Free Nanophotonic Biosensor for the Detection of Small Molecules

Sreekanth, K. V., Sreejith, S., Alapan, Y., Sitti, M., Lim, C. T., Singh, R.

Advanced Optical Materials, 2019 (article)

pi Sreekanth, K. V., Sreejith, S., Alapan, Y., Sitti, M., Lim, C. T., Singh, R. Microfluidics Integrated Lithography‐Free Nanophotonic Biosensor for the Detection of Small Molecules Advanced Optical Materials, 2019 (article)

ENGINEERING Bio-inspired robotic collectives

Sitti, M.

Nature, 567, pages: 314-315, Macmillan Publishers Ltd., London, England, 2019 (article)

pi Sitti, M. ENGINEERING Bio-inspired robotic collectives Nature, 567, pages: 314-315, Macmillan Publishers Ltd., London, England, 2019 (article)

Immihan Ceren Yasa, A. F. T. O. Y. H. C. M. S.

3D‐Printed Microrobotic Transporters with Recapitulated Stem Cell Niche for Programmable and Active Cell Delivery

Advanced Functional Materials , 29, 2019 (article)

pi Immihan Ceren Yasa, A. F. T. O. Y. H. C. M. S. 3D‐Printed Microrobotic Transporters with Recapitulated Stem Cell Niche for Programmable and Active Cell Delivery Advanced Functional Materials , 29, 2019 (article)

Reliable Real-Time Ball Tracking for Robot Table Tennis

Gomez-Gonzalez, S., Nemmour, Y., Schölkopf, B., Peters, J.

Robotics, 8(4):90, 2019 (article)

ei Gomez-Gonzalez, S., Nemmour, Y., Schölkopf, B., Peters, J. Reliable Real-Time Ball Tracking for Robot Table Tennis Robotics, 8(4):90, 2019 (article)

Peptide-Induced Biomineralization of Tin Oxide (SnO2) Nanoparticles for Antibacterial Applications

Singh, A. V., Jahnke, T., Xiao, Y., Wang, S., Yu, Y., David, H., Richter, G., Laux, P., Luch, A., Srivastava, A., Saxena, P. S., Bill, J., Sitti, M.

Journal of nanoscience and nanotechnology, 19, American Scientific Publishers, 2019 (article)

pi Singh, A. V., Jahnke, T., Xiao, Y., Wang, S., Yu, Y., David, H., Richter, G., Laux, P., Luch, A., Srivastava, A., Saxena, P. S., Bill, J., Sitti, M. Peptide-Induced Biomineralization of Tin Oxide (SnO2) Nanoparticles for Antibacterial Applications Journal of nanoscience and nanotechnology, 19, American Scientific Publishers, 2019 (article)

Electromechanical actuation of dielectric liquid crystal elastomers for soft robotics

Davidson, Z., Shahsavan, H., Guo, Y., Hines, L., Xia, Y., Yang, S., Sitti, M.

Bulletin of the American Physical Society, APS, 2019 (article)

pi Davidson, Z., Shahsavan, H., Guo, Y., Hines, L., Xia, Y., Yang, S., Sitti, M. Electromechanical actuation of dielectric liquid crystal elastomers for soft robotics Bulletin of the American Physical Society, APS, 2019 (article)

arXiv link (url) DOI Project Page [BibTex]

Optimizing the Execution of Dynamic Robot Movements With Learning Control

Koc, O., Maeda, G., Peters, J.

IEEE Transactions on Robotics, pages: 1-16, 2019 (article)

ei Koc, O., Maeda, G., Peters, J. Optimizing the Execution of Dynamic Robot Movements With Learning Control IEEE Transactions on Robotics, pages: 1-16, 2019 (article)

arXiv link (url) DOI Project Page [BibTex]

Learning to Serve: An Experimental Study for a New Learning From Demonstrations Framework

Koc, O., Peters, J.

IEEE Robotics and Automation Letters, 4(2):1784-1791, 2019 (article)

link (url) DOI Project Page [BibTex]

ei Koc, O., Peters, J. Learning to Serve: An Experimental Study for a New Learning From Demonstrations Framework IEEE Robotics and Automation Letters, 4(2):1784-1791, 2019 (article)

link (url) DOI Project Page [BibTex]

Simultaneous Six-Degree-of-Freedom Control of a Single-Body Magnetic Microrobot

Giltinan, J., Sitti, M.

IEEE Robotics and Automation Letters, 4, 2019 (article)

pi Giltinan, J., Sitti, M. Simultaneous Six-Degree-of-Freedom Control of a Single-Body Magnetic Microrobot IEEE Robotics and Automation Letters, 4, 2019 (article)

Monolithic shape-programmable dielectric liquid crystal elastomer actuators

Davidson, Z. S., Shahsavan, H., Aghakhani, A., Guo, Y., Hines, L., Xia, Y., Yang, S., Sitti, M.

arXiv preprint arXiv:1904.09606, 2019 (article)

pi Davidson, Z. S., Shahsavan, H., Aghakhani, A., Guo, Y., Hines, L., Xia, Y., Yang, S., Sitti, M. Monolithic shape-programmable dielectric liquid crystal elastomer actuators arXiv preprint arXiv:1904.09606, 2019 (article)

Bio-inspired composite microfibers for strong and reversible adhesion on smooth surfaces

Drotlef, D., Dayan, C., Sitti, M.

Integrative and comparative biology, 2019 (article)

pi Drotlef, D., Dayan, C., Sitti, M. Bio-inspired composite microfibers for strong and reversible adhesion on smooth surfaces Integrative and comparative biology, 2019 (article)

Elevation and Azimuth Rotational Actuation of an Untethered Millirobot by MRI Gradient Coils

Erin, O., Gilbert, H. B., Tabak, A. F., Sitti, M.

IEEE Transactions on Robotics, IEEE, 2019 (article)

pi Erin, O., Gilbert, H. B., Tabak, A. F., Sitti, M. Elevation and Azimuth Rotational Actuation of an Untethered Millirobot by MRI Gradient Coils IEEE Transactions on Robotics, IEEE, 2019 (article)

Learning to Navigate Endoscopic Capsule Robots

Turan, M., Almalioglu, Y., Gilbert, H. B., Mahmood, F., Durr, N. J., Araujo, H., Sarı, A. E., Ajay, A., Sitti, M.

IEEE Robotics and Automation Letters, 4, 2019 (article)

pi Turan, M., Almalioglu, Y., Gilbert, H. B., Mahmood, F., Durr, N. J., Araujo, H., Sarı, A. E., Ajay, A., Sitti, M. Learning to Navigate Endoscopic Capsule Robots IEEE Robotics and Automation Letters, 4, 2019 (article)

Eigendecompositions of Transfer Operators in Reproducing Kernel Hilbert Spaces

Klus, S., Schuster, I., Muandet, K.

Journal of Nonlinear Science, 2019, First Online: 21 August 2019 (article)

ei Klus, S., Schuster, I., Muandet, K. Eigendecompositions of Transfer Operators in Reproducing Kernel Hilbert Spaces Journal of Nonlinear Science, 2019, First Online: 21 August 2019 (article)

2009

Efficient Subwindow Search: A Branch and Bound Framework for Object Localization

Lampert, C., Blaschko, M., Hofmann, T.

IEEE Transactions on Pattern Analysis and Machine Intelligence, 31(12):2129-2142, December 2009 (article)

Abstract

Most successful object recognition systems rely on binary classification, deciding only if an object is present or not, but not providing information on the actual object location. To estimate the object‘s location, one can take a sliding window approach, but this strongly increases the computational cost because the classifier or similarity function has to be evaluated over a large set of candidate subwindows. In this paper, we propose a simple yet powerful branch and bound scheme that allows efficient maximization of a large class of quality functions over all possible subimages. It converges to a globally optimal solution typically in linear or even sublinear time, in contrast to the quadratic scaling of exhaustive or sliding window search. We show how our method is applicable to different object detection and image retrieval scenarios. The achieved speedup allows the use of classifiers for localization that formerly were considered too slow for this task, such as SVMs with a spatial pyramid kernel or nearest-neighbor classifiers based on the chi^2 distance. We demonstrate state-of-the-art localization performance of the resulting systems on the UIUC Cars data set, the PASCAL VOC 2006 data set, and in the PASCAL VOC 2007 competition.

2009

ei Lampert, C., Blaschko, M., Hofmann, T. Efficient Subwindow Search: A Branch and Bound Framework for Object Localization IEEE Transactions on Pattern Analysis and Machine Intelligence, 31(12):2129-2142, December 2009 (article)

Generation of three-dimensional random rotations in fitting and matching problems

Habeck, M.

Computational Statistics, 24(4):719-731, December 2009 (article)

Abstract

An algorithm is developed to generate random rotations in three-dimensional space that follow a probability distribution arising in fitting and matching problems. The rotation matrices are orthogonally transformed into an optimal basis and then parameterized using Euler angles. The conditional distributions of the three Euler angles have a very simple form: the two azimuthal angles can be decoupled by sampling their sum and difference from a von Mises distribution; the cosine of the polar angle is exponentially distributed and thus straighforward to generate. Simulation results are shown and demonstrate the effectiveness of the method. The algorithm is compared to other methods for generating random rotations such as a random walk Metropolis scheme and a Gibbs sampling algorithm recently introduced by Green and Mardia. Finally, the algorithm is applied to a probabilistic version of the Procrustes problem of fitting two point sets and applied in the context of protein structure superposition.

ei Habeck, M. Generation of three-dimensional random rotations in fitting and matching problems Computational Statistics, 24(4):719-731, December 2009 (article)

Adaptive Importance Sampling for Value Function Approximation in Off-policy Reinforcement Learning

Hachiya, H., Akiyama, T., Sugiyama, M., Peters, J.

Neural Networks, 22(10):1399-1410, December 2009 (article)

Abstract

Off-policy reinforcement learning is aimed at efficiently using data samples gathered from a policy that is different from the currently optimized policy. A common approach is to use importance sampling techniques for compensating for the bias of value function estimators caused by the difference between the data-sampling policy and the target policy. However, existing off-policy methods often do not take the variance of the value function estimators explicitly into account and therefore their performance tends to be unstable. To cope with this problem, we propose using an adaptive importance sampling technique which allows us to actively control the trade-off between bias and variance. We further provide a method for optimally determining the trade-off parameter based on a variant of cross-validation. We demonstrate the usefulness of the proposed approach through simulations.

ei Hachiya, H., Akiyama, T., Sugiyama, M., Peters, J. Adaptive Importance Sampling for Value Function Approximation in Off-policy Reinforcement Learning Neural Networks, 22(10):1399-1410, December 2009 (article)

Guest editorial: special issue on structured prediction

Parker, C., Altun, Y., Tadepalli, P.

Machine Learning, 77(2-3):161-164, December 2009 (article)

ei Parker, C., Altun, Y., Tadepalli, P. Guest editorial: special issue on structured prediction Machine Learning, 77(2-3):161-164, December 2009 (article)

Structured prediction by joint kernel support estimation

Lampert, CH., Blaschko, MB.

Machine Learning, 77(2-3):249-269, December 2009 (article)

ei Lampert, CH., Blaschko, MB. Structured prediction by joint kernel support estimation Machine Learning, 77(2-3):249-269, December 2009 (article)