Timothy Wolfe Bretl

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Research Output

2020

When Is a Helix Stable?

Borum, A. & Bretl, T., Aug 21 2020, In : Physical review letters. 125, 8, 088001.

Research output: Contribution to journalArticle

2019

Effect of discrete and continuous parameter variation on difficulty in automatic item generation

Chen, B., Zilles, C., West, M. & Bretl, T. W., Jan 1 2019, Artificial Intelligence in Education - 20th International Conference, AIED 2019, Proceedings. Isotani, S., Hastings, P., Ogan, A., McLaren, B., Millán, E. & Luckin, R. (eds.). Springer-Verlag, p. 71-83 13 p. (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); vol. 11625 LNAI).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Epstein, Project Maven, and Some Reasons to Think about Where We Get Our Funding [Ethical, Legal, and Societal Issues]

Bretl, T., Righetti, L. & Madhavan, R., Dec 2019, In : IEEE Robotics and Automation Magazine. 26, 4, p. 8-13 6 p., 8931077.

Research output: Contribution to journalArticle

Every university should have a computer-based testing facility

Zilles, C., West, M., Herman, G. & Bretl, T., 2019, CSEDU 2019 - Proceedings of the 11th International Conference on Computer Supported Education. Lane, H., Zvacek, S. & Uhomoibhi, J. (eds.). SciTePress, p. 414-420 7 p. (CSEDU 2019 - Proceedings of the 11th International Conference on Computer Supported Education; vol. 1).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Open Access

Large-area MRI-compatible epidermal electronic interfaces for prosthetic control and cognitive monitoring

Tian, L., Zimmerman, B., Akhtar, A., Yu, K. J., Moore, M., Wu, J., Larsen, R. J., Lee, J. W., Li, J., Liu, Y., Metzger, B., Qu, S., Guo, X., Mathewson, K. E., Fan, J. A., Cornman, J., Fatina, M., Xie, Z., Ma, Y., Zhang, J. & 9 others, Zhang, Y., Dolcos, F., Fabiani, M., Gratton, G., Bretl, T., Hargrove, L. J., Braun, P. V., Huang, Y. & Rogers, J. A., Mar 1 2019, In : Nature biomedical engineering. 3, 3, p. 194-205 12 p.

Research output: Contribution to journalArticle

Making testing less trying: Lessons learned from operating a computer-based testing facility

Zilles, C., West, M., Mussulman, D. & Bretl, T., Mar 4 2019, Frontiers in Education: Fostering Innovation Through Diversity, FIE 2018 - Conference Proceedings. Institute of Electrical and Electronics Engineers Inc., 8658551. (Proceedings - Frontiers in Education Conference, FIE; vol. 2018-October).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2018

Controlling sensation intensity for electrotactile stimulation in human-machine interfaces

Akhtar, A., Sombeck, J., Boyce, B. & Bretl, T., Apr 2018, In : Science Robotics. 3, 17, eaap9770.

Research output: Contribution to journalArticle

Open Access

Design and Development of a Dynamically, Scaled Distributed Electric Propulsion Aircraft Testbed

Pieper, K., Perry, A., Ansell, P. & Bretl, T., Nov 29 2018, 2018 AIAA/IEEE Electric Aircraft Technologies Symposium, EATS 2018. Institute of Electrical and Electronics Engineers Inc., 8552755. (2018 AIAA/IEEE Electric Aircraft Technologies Symposium, EATS 2018).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Experimental Evaluation of the Planar Assumption in Magnetic Positioning

Hanley, D., Zhang, X., Dantas De Oliveira, A. S., Steinberg, D. & Bretl, T., Nov 13 2018, IPIN 2018 - 9th International Conference on Indoor Positioning and Indoor Navigation. Institute of Electrical and Electronics Engineers Inc., 8533828. (IPIN 2018 - 9th International Conference on Indoor Positioning and Indoor Navigation).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

FEATS: Synthetic feature tracks for structure from motion evaluation

Degol, J., Lee, J. Y., Kataria, R., Yuan, D., Bretl, T. & Hoiem, D., Oct 12 2018, Proceedings - 2018 International Conference on 3D Vision, 3DV 2018. Institute of Electrical and Electronics Engineers Inc., p. 352-361 10 p. 8490986. (Proceedings - 2018 International Conference on 3D Vision, 3DV 2018).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Feature-constrained Active Visual SLAM for Mobile Robot Navigation

Deng, X., Zhang, Z., Sintov, A., Huang, J. & Bretl, T. W., Sep 10 2018, 2018 IEEE International Conference on Robotics and Automation, ICRA 2018. Institute of Electrical and Electronics Engineers Inc., p. 7233-7238 6 p. 8460721. (Proceedings - IEEE International Conference on Robotics and Automation).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Improved Structure from Motion Using Fiducial Marker Matching

DeGol, J., Bretl, T. & Hoiem, D., Jan 1 2018, Computer Vision – ECCV 2018 - 15th European Conference, 2018, Proceedings. Ferrari, V., Sminchisescu, C., Hebert, M. & Weiss, Y. (eds.). Springer-Verlag Berlin Heidelberg, p. 281-296 16 p. (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); vol. 11207 LNCS).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Motion planning of fully actuated closed kinematic chains with revolute joints: A comparative analysis

Sintov, A., Borum, A. & Bretl, T., Oct 2018, In : IEEE Robotics and Automation Letters. 3, 4, p. 2886-2893 8 p.

Research output: Contribution to journalArticle

Teaching undergraduate courses on robotics and control in prison

Bretl, T., Sep 2018, Mechanical Engineering, 140, 9, p. S11-S16.

Research output: Contribution to specialist publicationArticle

Open Access

The performance of 9-11-year-old children using an SSVEP-based BCI for target selection

Norton, J. J. S., Mullins, J., Alitz, B. E. & Bretl, T., Jul 27 2018, In : Journal of Neural Engineering. 15, 5, 056012.

Research output: Contribution to journalArticle

2017

A compliant four-bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant

Choi, K. Y., Akhtar, A. & Bretl, T., Jul 21 2017, ICRA 2017 - IEEE International Conference on Robotics and Automation. Institute of Electrical and Electronics Engineers Inc., p. 6694-6699 6 p. 7989791. (Proceedings - IEEE International Conference on Robotics and Automation).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

A portable, arbitrary waveform, multichannel constant current electrotactile stimulator

Cornman, J., Akhtar, A. & Bretl, T., Aug 10 2017, 8th International IEEE EMBS Conference on Neural Engineering, NER 2017. IEEE Computer Society, p. 300-303 4 p. 8008350. (International IEEE/EMBS Conference on Neural Engineering, NER).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

ChromaTag: A Colored Marker and Fast Detection Algorithm

Degol, J., Bretl, T. & Hoiem, D., Dec 22 2017, Proceedings - 2017 IEEE International Conference on Computer Vision, ICCV 2017. Institute of Electrical and Electronics Engineers Inc., p. 1481-1490 10 p. 8237426. (Proceedings of the IEEE International Conference on Computer Vision; vol. 2017-October).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Computational curriculum for MatSE undergraduates

Kononov, A., Bellon, P., Bretl, T., Ferguson, A. L., Herman, G. L., Kilian, K. A., Krogstad, J. A., Leal, C., Maass, R., Schleife, A., Shang, J. K., Trinkle, D. R. & West, M., Jun 24 2017, In : ASEE Annual Conference and Exposition, Conference Proceedings. 2017-June

Research output: Contribution to journalConference article

Estimation of distal arm joint angles from EMG and shoulder orientation for transhumeral prostheses

Akhtar, A., Aghasadeghi, N., Hargrove, L. & Bretl, T., Aug 2017, In : Journal of Electromyography and Kinesiology. 35, p. 86-94 9 p.

Research output: Contribution to journalArticle

MagPIE: A dataset for indoor positioning with magnetic anomalies

Hanley, D., Faustino, A. B., Zelman, S. D., Degenhardt, D. A. & Bretl, T., Nov 20 2017, 2017 International Conference on Indoor Positioning and Indoor Navigation, IPIN 2017. Institute of Electrical and Electronics Engineers Inc., p. 1-8 8 p. (2017 International Conference on Indoor Positioning and Indoor Navigation, IPIN 2017; vol. 2017-January).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Reduction of Sufficient Conditions for Optimal Control Problems with Subgroup Symmetry

Borum, A. & Bretl, T., Jul 2017, In : IEEE Transactions on Automatic Control. 62, 7, p. 3209-3224 16 p., 7742897.

Research output: Contribution to journalArticle

The elicitation of steady-state visual evoked potentials during sleep

Norton, J. J. S., Umunna, S. & Bretl, T., Apr 1 2017, In : Psychophysiology. 54, 4, p. 496-507 12 p.

Research output: Contribution to journalArticle

2016

A low-cost, open-source, compliant hand for enabling sensorimotor control for people with transradial amputations

Akhtar, A., Choi, K. Y., Fatina, M., Cornman, J., Wu, E., Sombeck, J., Yim, C., Slade, P., Lee, J., Moore, J., Gonzales, D., Wu, A., Anderson, G., Rotter, D., Shin, C. & Bretl, T., Oct 13 2016, 2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2016. Institute of Electrical and Electronics Engineers Inc., p. 4642-4645 4 p. 7591762. (Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS; vol. 2016-October).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

An Epidermal Stimulation and Sensing Platform for Sensorimotor Prosthetic Control, Management of Lower Back Exertion, and Electrical Muscle Activation

Xu, B., Akhtar, A., Liu, Y., Chen, H., Yeo, W. H., Park, S., Boyce, B., Kim, H., Yu, J., Lai, H. Y., Jung, S., Zhou, Y., Kim, J., Cho, S., Huang, Y., Bretl, T. & Rogers, J. A., Jan 1 2016, In : Advanced Materials. 28, 22, p. 4462-4471 10 p.

Research output: Contribution to journalArticle

An improved model-based observer for inertial navigation for quadrotors with low cost IMUs

Hanley, D. & Bretl, T., 2016, AIAA Guidance, Navigation, and Control Conference. American Institute of Aeronautics and Astronautics Inc, AIAA, (2016 AIAA Guidance, Navigation, and Control Conference).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Automatic grasp selection using a camera in a hand prosthesis

Degol, J., Akhtar, A., Manja, B. & Bretl, T., Oct 13 2016, 2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2016. Institute of Electrical and Electronics Engineers Inc., p. 431-434 4 p. 7590732. (Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS; vol. 2016-October).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Epidermal mechano-acoustic sensing electronics for cardiovascular diagnostics and human-machine interfaces

Liu, Y., Norton, J. J. S., Qazi, R., Zou, Z., Ammann, K. R., Liu, H., Yan, L., Tran, P. L., Jang, K. I., Lee, J. W., Zhang, D., Kilian, K. A., Jung, S. H., Bretl, T., Xiao, J., Slepian, M. J., Huang, Y., Jeong, J. W. & Rogers, J. A., Nov 2016, In : Science Advances. 2, 11, e1601185.

Research output: Contribution to journalArticle

Flexible Electronics: An Epidermal Stimulation and Sensing Platform for Sensorimotor Prosthetic Control, Management of Lower Back Exertion, and Electrical Muscle Activation (Adv. Mater. 22/2016)

Xu, B., Akhtar, A., Liu, Y., Chen, H., Yeo, W. H., Park, S. I. I., Boyce, B., Kim, H., Yu, J., Lai, H. Y., Jung, S., Zhou, Y., Kim, J., Cho, S., Huang, Y., Bretl, T. & Rogers, J. A., Jun 8 2016, In : Advanced Materials. 28, 22, 1 p.

Research output: Contribution to journalComment/debate

Helices, relative equilibria, and optimality on the special Euclidean group

Borum, A. & Bretl, T. W., Dec 27 2016, 2016 IEEE 55th Conference on Decision and Control, CDC 2016. Institute of Electrical and Electronics Engineers Inc., p. 185-190 6 p. 7798267. (2016 IEEE 55th Conference on Decision and Control, CDC 2016).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Sufficient conditions for a path-connected set of local solutions to an optimal control problem

Borum, A. & Bretl, T., Jan 1 2016, In : SIAM Journal on Applied Mathematics. 76, 3, p. 976-999 24 p.

Research output: Contribution to journalArticle

2015

An SSVEP-based brain-computer interface for text spelling with adaptive queries that maximize information gain rates

Akce, A., Norton, J. J. S. & Bretl, T. W., Sep 1 2015, In : IEEE Transactions on Neural Systems and Rehabilitation Engineering. 23, 5, p. 857-866 10 p., 6971133.

Research output: Contribution to journalArticle

A passive mechanism for relocating payloads with a quadrotor

Degol, J., Hanley, D., Aghasadeghi, N. & Bretl, T., Dec 11 2015, IROS Hamburg 2015 - Conference Digest: IEEE/RSJ International Conference on Intelligent Robots and Systems. Institute of Electrical and Electronics Engineers Inc., p. 4337-4342 6 p. 7353992. (IEEE International Conference on Intelligent Robots and Systems; vol. 2015-December).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Manipulation planning with contacts for an extensible elastic rod by sampling on the submanifold of static equilibrium configurations

Roussel, O., Borum, A., Taix, M. & Bretl, T., Jun 29 2015, In : Proceedings - IEEE International Conference on Robotics and Automation. 2015-June, June, p. 3116-3121 6 p., 7139627.

Research output: Contribution to journalConference article

Soft, curved electrode systems capable of integration on the auricle as a persistent brain-computer interface

Norton, J. J. S., Lee, D. S., Lee, J. W., Lee, W., Kwon, O., Won, P., Jung, S. Y., Cheng, H., Jeong, J. W., Akce, A., Umunna, S., Na, I., Kwon, Y. H., Wang, X. Q., Liu, Z. J., Paik, U., Huang, Y., Bretl, T., Yeo, W. H., Rogers, J. A. & 1 others, Bao, Z., Mar 31 2015, In : Proceedings of the National Academy of Sciences of the United States of America. 112, 13, p. 3920-3925 6 p.

Research output: Contribution to journalArticle

Tact: Design and performance of an open-source, affordable, myoelectric prosthetic hand

Slade, P., Akhtar, A., Nguyen, M. & Bretl, T. W., Jun 29 2015, In : Proceedings - IEEE International Conference on Robotics and Automation. 2015-June, June, p. 6451-6456 6 p., 7140105.

Research output: Contribution to journalConference article

The free configuration space of a Kirchhoff elastic rod is path-connected

Borum, A. & Bretl, T., Jun 29 2015, In : Proceedings - IEEE International Conference on Robotics and Automation. 2015-June, June, p. 2958-2964 7 p., 7139604.

Research output: Contribution to journalConference article

2014

A two-stage suboptimal approximation for variable compliance and torque control

Geoffroy, P., Bordron, O., Mansard, N., Raison, M., Stasse, O. & Bretl, T., Jul 22 2014, 2014 European Control Conference, ECC 2014. Institute of Electrical and Electronics Engineers Inc., p. 1151-1157 7 p. 6862557. (2014 European Control Conference, ECC 2014).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Controlling many differential-drive robots with uniform control inputs

Becker, A., Onyuksel, C., Bretl, T. & McLurkin, J., Nov 11 2014, In : International Journal of Robotics Research. 33, 13, p. 1626-1644 19 p.

Research output: Contribution to journalArticle

Demonstration: Passive mechanical skin stretch for multiple degree-of-freedom proprioception in a hand prosthesis

Akhtar, A., Nguyen, M., Wan, L., Boyce, B., Slade, P. & Bretl, T., Jan 1 2014, Haptics: Neuroscience, Devices, Modeling, and Applications - 9th International Conference, EuroHaptics 2014, Proceedings. Auvray, M., Duriez, C., Duriez, C. & Auvray, M. (eds.). Springer-Verlag Berlin Heidelberg, p. 413-415 3 p. (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); vol. 8619).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Efficient motion planning for quasi-static elastic rods using geometry neighborhood approximation

Roussel, O., Taïx, M. & Bretl, T., 2014, AIM 2014 - IEEE/ASME International Conference on Advanced Intelligent Mechatronics. Institute of Electrical and Electronics Engineers Inc., p. 1024-1029 6 p. 6878215. (IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Geometric optimal control for symmetry breaking cost functions

Borum, A. D. & Bretl, T., Jan 1 2014, In : Proceedings of the IEEE Conference on Decision and Control. 2015-February, February, p. 5855-5861 7 p., 7040306.

Research output: Contribution to journalConference article

Interpreting lateral dynamic weight shifts using a simple inverted pendulum model

Kennedy, M. W., Bretl, T. & Schmiedeler, J. P., May 2014, In : Gait and Posture. 40, 1, p. 134-139 6 p.

Research output: Contribution to journalArticle

Inverse optimal control for differentially flat systems with application To locomotion modeling

Aghasadeghi, N. & Bretl, T., Sep 22 2014, In : Proceedings - IEEE International Conference on Robotics and Automation. p. 6018-6025 8 p., 6907746.

Research output: Contribution to journalConference article

Passive mechanical skin stretch for multiple degree-of-freedom proprioception in a hand prosthesis

Akhtar, A., Nguyen, M., Wan, L., Boyce, B., Slade, P. & Bretl, T., Jan 1 2014, Haptics: Neuroscience, Devices, Modeling, and Applications - 9th International Conference, EuroHaptics 2014, Proceedings. Auvray, M., Duriez, C., Duriez, C. & Auvray, M. (eds.). Springer-Verlag, p. 120-128 9 p. (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics); vol. 8619).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Playing checkers with your mind: An interactive multiplayer hardware game platform for brain-computer interfaces

Akhtar, A., Norton, J. J. S., Kasraie, M. & Bretl, T., Nov 2 2014, 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2014. Institute of Electrical and Electronics Engineers Inc., p. 1650-1653 4 p. 6943922. (2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC 2014).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Quasi-static manipulation of a planar elastic rod using multiple robotic grippers

Mukadam, M., Borum, A. & Bretl, T., Oct 31 2014, IROS 2014 Conference Digest - IEEE/RSJ International Conference on Intelligent Robots and Systems. Institute of Electrical and Electronics Engineers Inc., p. 55-60 6 p. 6942540. (IEEE International Conference on Intelligent Robots and Systems).

Research output: Chapter in Book/Report/Conference proceedingConference contribution