Shankarachary Ragi

________________________________________ Assistant Professor, Department of Electrical Engineering South Dakota School of Mines and Technology ________________________________________ Office: EEP 319 Email: shankarachary.ragi@sdsmt.edu Google Scholar Profile Curriculum Vitae

I received my bachelor’s and master’s degrees in electrical engineering from Indian Institute of Technology Madras in 2009, and the Ph.D. degree in electrical and computer engineering from Colorado State University in 2014 under the supervision of Prof. Edwin K. P. Chong. Before joining SDSMT, I held a postdoctoral position at Arizona State University in the School of Mathematical and Statistical Sciences working with Prof. Hans D. Mittelmann.

My research primarily deals with optimal control, decision making under uncertainty, predictive modeling, data analytics, and optimization in autonomous/semi-autonomous systems.

I am a Senior Member of IEEE.

News

Publications

Journal Papers:

[J13] S. Ragi, H. Rahman, J. Duckworth, K. Jawaharraj, P. Chundi, and V. Gadhamshetty, "Artificial Intelligence-driven Image Analysis of Bacterial Cells and Biofilms," IEEE/ACM Transactions on Computational Biology and Bioinformatics, to appear. (pre-print available at DOI: 10.1109/TCBB.2021.3138304)

[J12] S. Doly, A. Chiriyath, H. D. Mittelmann, D. W. Bliss, S. Ragi, "Waveform codesign for radar-communications spectral coexistence via dynamic programming," IEEE Transactions on Aerospace and Electronic Systems, to appear.

[J11] S. Ragi, H. D. Mittelmann, "Random-sampling Monte-Carlo tree search methods for cost approximation in long-horizon optimal control," IEEE Control Systems Letters (L-CSS), vol. 5, no. 5, pp. 1759--1764, November 2021.

[J10] M. A. Hossen, P. Diwakar, S. Ragi, "Total nitrogen estimation in agricultural soils via aerial multispectral imaging and LIBS," Scientific Reports, vol. 11, no. 12693, June 2021.

[J9] M. Azam, H. D. Mittelmann, and S. Ragi "UAV Formation Shape Control via Decentralized Markov Decision Processes," Algorithms, special issue on Algorithms in Stochastic Models, vol. 14, no. 3, March 2021.

[J8] A. Chiriyath, S. Ragi, H. D. Mittelmann, D. W. Bliss, "Radar Waveform Optimization for Joint Radar Communications Performance," Electronics, special issue on Cooperative Communications for Future Wireless Systems, vol. 8, no. 12, December 2019.

[J7] S. Ragi, E. K. P. Chong, and H. D. Mittelmann, "Polynomial-time methods to solve unimodular quadratic programs with performance guarantees," IEEE Transactions on Aerospace and Electronic Systems, vol. 55, no. 5, pp. 2118--2127, October 2019, DOI: 10.1109/TAES.2018.2881366.

[J6] A. Chiriyath, S. Ragi, H. D. Mittelmann, D. W. Bliss, "Novel Radar Waveform Optimization for a Cooperative Radar-Communications System," IEEE Transactions on Aerospace and Electronic Systems , vol. 55, no. 3, pp. 1160--1173, April 2019.

[J5] S. Ragi, H. D. Mittelmann, and E. K. P. Chong, "Directional sensor control: Heuristic approaches," IEEE Sensors Journal, vol. 15, no. 1, pp. 374--381, January 2015. DOI.

[J4] S. Ragi and E. K. P. Chong, "Decentralized guidance control of UAVs with explicit optimization of communication," Journal of Intelligent and Robotic Systems, special issue on Unmanned Aircraft Systems (UAS), Part I, vol. 73, no. 1-4, pp. 811--822, January 2014. DOI.

[J3] S. Ragi and E. K. P. Chong, "UAV path planning in a dynamic environment via partially observable Markov decision process," IEEE Transactions on Aerospace and Electronic Systems, vol. 49, no. 4, pp. 2397--2412, October 2013.

[J2] S. Ragi, C. S. Tan and E. K. P. Chong, "Guidance of autonomous amphibious vehicles for flood rescue support," Mathematical Problems in Engineering, special issue on Mathematical Modeling for Resources and Environmental Systems, vol. 2013, Article ID 528162, 9 pages, 2013. DOI. Link

[J1] A. V. Weigel, S. Ragi, M. L. Reid, E. K. P. Chong, M. M. Tamkun, and D. Krapf, "Obstructed diffusion propagator analysis for single-particle tracking," Physical Review E, vol. 85, no. 4, paper 041924, April 2012. DOI

Conference Papers and Presentations:

[C16] D. Abeyrathna, T. Life, S. Ragi, R. Sani, and P. Chundi, "Segmentation of Bacterial Cells in Biofilms Using an Overlapped Ellipse Fitting Technique," in Proceedings of the IEEE Computational Biofilm Engineering and Applications Workshop, Houston, TX, Dec 09--12, 2021, to appear.

[C15] S. A. Doly, A. Chiriyath, H. D. Mittelmann, D. W. Bliss, and S. Ragi, "A decision theoretic approach for waveform design in joint radar communications applications," in Proceedings of the 54th Asilomar Conference on Signals, Systems and Computers (Asilomar 2020), Pacific Grove, CA, Nov 01--04, 2020, pp. 6-11.

[C14] A. D. Chakravarthy, P. Chundi, M. Subramaniam, S. Ragi, and V. R. Gadhamshetty, "A Thrifty Annotation Generation Approach for Semantic Segmentation of Biofilms," in Proceedings of the 20th IEEE International Conference on Bioinformatics and Bioengineering (BIBE), Virtual Conference, Oct 26--28, 2020, pp. 602--607.

[C13] S. Ragi and H. D. Mittelmann, "Random-Sampling Multipath Hypothesis Propagation for Cost Approximation in Long-Horizon Optimal Control," in Proceedings of the 2020 IEEE Conference on Control Technology and Applications (CCTA), Montreal, Canada, August 24--26, 2020, pp. 14--18.

[C12] H. Rahman, J. Duckworth, S. Ragi, P. Chundi, G. Chilkoor, and V. Gadhamshetty, "Deep Learning Approach to Extract Geometric Features of Bacterial Cells in Biofilms," in The 16th International Conference on Data Science (ICDATA'20), Las Vegas, NV, July 27--30, 2020, to appear.

[C11] M. Azam and S. Ragi, "Decentralized formation shape control of UAV swarm using dynamic programming," in Proceedings of SPIE 11423, Signal Processing, Sensor/Information Fusion, and Target Recognition XXIX, 114230I, Anaheim, CA, April 26--30, 2020.

[C10] M. Azam, S. Dey, H. D. Mittelmann, and S. Ragi, "Average consensus-based data fusion in networked sensor systems for target tracking," in 2020 10th Annual Computing and Communication Workshop and Conference (CCWC), Las Vegas, NV, Jan 06--08, 2020, pp. 964--969.

[C9] S. Ragi, S. Dey, M. Azam, and H. D. Mittelmann, "Competing objective optimization in networked swarm systems," in Proceedings of the 2019 IEEE National Aerospace & Electronics Conference (NAECON) , Dayton, OH, July 15--19, 2019, pp. 88--91.

[C8] C. Kaji, R. Hoover, and S. Ragi, "Underwater navigation using geomagnetic field variations," in Proceedings of the 2019 IEEE International Conference on Electro Information Technology (EIT), Brookings, SD, May 20--22, 2019, pp. 339--344.

[C7] S. Ragi and H. D. Mittelmann, "Mixed-integer nonlinear programming formulation of a UAV path optimization problem ," in Proceedings of the 2017 American Control Conference (ACC 2017), Seattle, WA, May 24--26, 2017, pp. 406--411.

[C6] S. Ragi, E. K. P. Chong, and H. D. Mittelmann, "Heuristic methods for designing unimodular code sequences with performance guarantees," in Proceedings of IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2017), New Orleans, LA, March 5--9, 2017, pp. 3221--3225.

[C5] S. Ragi, H. D. Mittelmann, and E. K. P. Chong, "Directional sensor control for maximizing information gain," in Proceedings of SPIE Optical Engineering + Applications (SPIE Vol. 8857), part of SPIE Optics + Photonics Symposium, San Diego, California, August 25--29, 2013, paper number 8857-19.

[C4] S. Ragi, C. S. Tan, and E. K. P. Chong, "Feasibility study of POMDP in autonomous amphibious vehicle guidance," in Proceedings of the 2013 IFAC Symposium on Intelligent Autonomous Vehicles (IAV 2013), Gold Coast, Australia, June 26--28, June 2013, pp. 85--90.

[C3] S. Ragi and E. K. P. Chong, "Decentralized control of unmanned aerial vehicles for multitarget tracking," in Proceedings of the 2013 International Conference on Unmanned Aircraft Systems (ICUAS'13), Atlanta, Georgia, May 28--31, 2013, pp. 260--268.

[C2] S. Ragi and E. K. P. Chong, "Dynamic UAV path planning for multitarget tracking," in Proceedings of the 2012 American Control Conference (ACC 2012), Montreal, Canada, June 27--29, 2012, Paper ThC04.3, pp. 3845--3850.

[C1] S. Ragi and E. K. P. Chong, "Dynamic UAV path planning for multi-target tracking," presented (poster) at the 1st Southwest Workshop on Theory and Applications of Cyber-Physical Systems, Tucson, Arizona, March 10--11, 2011.

Book Chapters

• S. Ragi and E. K. P. Chong, "UAV guidance algorithms via partially observable Markov decision processes," in Handbook of Unmanned Aerial Vehicles, K. P. Valavanis and G. J. Vachtsevanos, Eds., Dordrecht, Netherlands: Springer, ISBN 978-90-481-9706-4, 2015, ch. 73, Section XIII, pp. 1775--1810.