Header logo is


2016


no image
Quantifying Therapist Practitioner Roles Using Video-based Analysis: Can We Reliably Model Therapist-Patient Interactions During Task-Oriented Therapy?

Mendonca, R., Johnson, M. J., Laskin, S., Adair, L., Mohan, M.

pages: E55-E56, Abstract in the Archives of Physical Medicine and Rehabilitation, October 2016 (misc)

hi

DOI [BibTex]

2016


DOI [BibTex]


Gaussian Process-Based Predictive Control for Periodic Error Correction
Gaussian Process-Based Predictive Control for Periodic Error Correction

Klenske, E. D., Zeilinger, M., Schölkopf, B., Hennig, P.

IEEE Transactions on Control Systems Technology , 24(1):110-121, 2016 (article)

ei pn

PDF DOI [BibTex]

PDF DOI [BibTex]


Dual Control for Approximate Bayesian Reinforcement Learning
Dual Control for Approximate Bayesian Reinforcement Learning

Klenske, E. D., Hennig, P.

Journal of Machine Learning Research, 17(127):1-30, 2016 (article)

ei pn

PDF link (url) [BibTex]

PDF link (url) [BibTex]


no image
Design of a Low-Cost Platform for Autonomous Mobile Service Robots

Eaton, E., Mucchiani, C., Mohan, M., Isele, D., Luná, J. M., Clingerman, C.

Workshop paper (7 pages) presented at the 25th International Joint Conference on Artificial Intelligence (IJCAI) Workshop on Autonomous Mobile Service Robots, New York, USA, 2016 (misc)

Abstract
Most current autonomous mobile service robots are either expensive commercial platforms or custom manufactured for research environments, limiting their availability. We present the design for a lowcost service robot based on the widely used TurtleBot 2 platform, with the goal of making service robots affordable and accessible to the research, educational, and hobbyist communities. Our design uses a set of simple and inexpensive modifications to transform the TurtleBot 2 into a 4.5ft (1.37m) tall tour-guide or telepresence-style robot, capable of performing a wide variety of indoor service tasks. The resulting platform provides a shoulder-height touchscreen and 3D camera for interaction, an optional low-cost arm for manipulation, enhanced onboard computation, autonomous charging, and up to 6 hours of runtime. The resulting platform can support many of the tasks performed by significantly more expensive service robots. For compatibility with existing software packages, the service robot runs the Robot Operating System (ROS).

hi

link (url) [BibTex]

link (url) [BibTex]

2015


no image
Probabilistic Interpretation of Linear Solvers

Hennig, P.

SIAM Journal on Optimization, 25(1):234-260, 2015 (article)

ei pn

Web PDF link (url) DOI [BibTex]

2015


Web PDF link (url) DOI [BibTex]


no image
Probabilistic numerics and uncertainty in computations

Hennig, P., Osborne, M. A., Girolami, M.

Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 471(2179), 2015 (article)

Abstract
We deliver a call to arms for probabilistic numerical methods: algorithms for numerical tasks, including linear algebra, integration, optimization and solving differential equations, that return uncertainties in their calculations. Such uncertainties, arising from the loss of precision induced by numerical calculation with limited time or hardware, are important for much contemporary science and industry. Within applications such as climate science and astrophysics, the need to make decisions on the basis of computations with large and complex data have led to a renewed focus on the management of numerical uncertainty. We describe how several seminal classic numerical methods can be interpreted naturally as probabilistic inference. We then show that the probabilistic view suggests new algorithms that can flexibly be adapted to suit application specifics, while delivering improved empirical performance. We provide concrete illustrations of the benefits of probabilistic numeric algorithms on real scientific problems from astrometry and astronomical imaging, while highlighting open problems with these new algorithms. Finally, we describe how probabilistic numerical methods provide a coherent framework for identifying the uncertainty in calculations performed with a combination of numerical algorithms (e.g. both numerical optimizers and differential equation solvers), potentially allowing the diagnosis (and control) of error sources in computations.

ei pn

PDF DOI [BibTex]

PDF DOI [BibTex]

2013


Quasi-Newton Methods: A New Direction
Quasi-Newton Methods: A New Direction

Hennig, P., Kiefel, M.

Journal of Machine Learning Research, 14(1):843-865, March 2013 (article)

Abstract
Four decades after their invention, quasi-Newton methods are still state of the art in unconstrained numerical optimization. Although not usually interpreted thus, these are learning algorithms that fit a local quadratic approximation to the objective function. We show that many, including the most popular, quasi-Newton methods can be interpreted as approximations of Bayesian linear regression under varying prior assumptions. This new notion elucidates some shortcomings of classical algorithms, and lights the way to a novel nonparametric quasi-Newton method, which is able to make more efficient use of available information at computational cost similar to its predecessors.

ei ps pn

website+code pdf link (url) [BibTex]

2013


website+code pdf link (url) [BibTex]


no image
Analytical probabilistic modeling for radiation therapy treatment planning

Bangert, M., Hennig, P., Oelfke, U.

Physics in Medicine and Biology, 58(16):5401-5419, 2013 (article)

ei pn

PDF DOI [BibTex]

PDF DOI [BibTex]