San Bruno, CA USA
jramakrishnan [ at ] walmartlabs [ dot ] com
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Welcome! I am a staff data scientist on the smart pricing team at
Walmart Labs. Previously, I was a research associate in the optimization group at the Wisconsin Institute for Discovery (WID), University of Wisconsin-Madison. My primary research area is operations research; I typically use mathematical modeling, optimization, statistical/data analysis, and machine learning approaches to make better decisions for real-world problems. I enjoy working on various kinds of applications, including problems in revenue management (e.g., price optimization), in medical decision making (e.g., radiation therapy cancer treatment), agricultural management, and energy management (e.g., stochastic unit commitment).
I received my Ph.D. degree at
MIT, Department of Electrical Engineering and Computer Science
(EECS), and was affiliated with the Laboratory for Information and Decision Systems (LIDS). My advisors were Prof. John N. Tsitsiklis (MIT), Prof. David Craft (MGH), and Prof. Thomas Bortfeld (MGH). I previously received my Bachelor's and Master's degrees in Electrical and Computer Engineering (ECE) from Georgia Tech.
H. Badri, J. Ramakrishnan, and K. Leder, "Minimizing metastatic risk in radiotherapy fractionation schedules," accepted, Physics in Medicine and Biology, Sept 2015.
T. Bortfeld, J. Ramakrishnan, J. N. Tsitsiklis, and J. Unkelbach, "Optimization of radiation therapy fractionation schedules in the presence of tumor repopulation," accepted May 2015, INFORMS Journal on Computing.
J. Unkelbach, D. Craft, T. Hong, D. Papp, J. Ramakrishnan, E. Salari, J. Wolfgang, and T. Bortfeld, "Exploiting tumor shrinkage through temporal optimization of radiotherapy," Physics in Medicine and Biology, Vol. 59, 2014, pp. 3059-3079, doi.
J. Unkelbach, D. Craft, E. Salari, J. Ramakrishnan, and T. Bortfeld, "The dependence of optimal fractionation schemes on the spatial dose distribution," Physics in Medicine and Biology, Vol. 58, 2013, pp. 159-167, doi. News article featured on medicalphysicsweb ( link)
J. Ramakrishnan, D. Craft, T. Bortfeld, and J. N. Tsitsiklis, "A dynamic programming approach to adaptive fractionation," Physics in Medicine and Biology, Vol. 57, 2012, pp. 1203-1216, doi.
S. Dirkse, M. C. Ferris, and J. Ramakrishnan, "GDXMRW: Interfacing GAMS and MATLAB,", [see also wisc link ], documentation part of GAMS 24.3, Aug 2014.
J. Ramakrishnan and M. C. Ferris, "SOCP Radiotherapy Benchmark Test Case in CBLIB," documentation of test case in , Oct 2014. Poster reference cblib, the conic benchmark library here.
Minimizing metastatic risk in radiotherapy
(Poster) Health Systems Optimization Workshop, Northwestern University, Chicago, IL, Sept 2014
Interfacing GAMS and Matlab for large-scale optimization
(Invited) INFORMS Annual Meeting, San Francisco, CA, Nov 2014
( Poster) High-performance numerical methods supporting radiation therapy treatment planning workshop II, Lehigh University, Bethlehem, PA, May 2014
Dynamic optimization in radiation therapy
(Invited) Arizona State University, Tempe, AZ, Jan 2015
Systems Information Learning Optimization (SILO) Seminar, University of Wisconsin, Madison, WI, Nov 2013
(Invited) INFORMS Annual Meeting, Minneapolis, MN, Oct 2013
Ph.D. Defense, MIT, Cambridge, MA, May 2013
Optimization of radiation therapy fractionation schedules in the presence of tumor repopulation
9th International Conference on Dose, Time and Fractionation in Radiation Oncology, University of Wisconsin, Madison, WI, Sept 2013
(Invited) INFORMS Healthcare Meeting, Chicago, IL, June 2013
LIDS Student Conference, MIT, Cambridge, MA, Feb 2013
(Invited) INFORMS Annual Meeting, Phoenix, AZ, Oct 2012
Dynamic programming approach to adaptive delivery in radiation therapy
(Poster) The American Association of Physicists in Medicine (AAPM) Meeting, Charlotte, NC, July 2012
LIDS Student Conference, MIT, Cambridge, MA, Feb 2012, Jan 2011
INFORMS Healthcare Meeting, Montreal, Canada, June 2011
(Poster) High-performance numerical methods supporting radiation therapy treatment planning workshop, Banff, Canada, March 2011
(Invited) Physics Seminar, Massachusetts General Hospital, Boston, MA, June 2010
List of Co-Authors
Thomas Bortfeld (MGH), David Craft (MGH), Steven Dirkse (GAMS), Michael C. Ferris (UW-Madison), Ted Hong, MD (MGH), Kevin Leder (UMN), Dávid Papp (MGH), Ehsan Salari (Wichita), John N. Tsitsiklis (MIT), Jan Unkelbach (MGH), John Wolfgang (MGH)
Linear Programming, Optimization Modeling -- GAMS (UW-Madison), Guest Lecturer (2014 - 2015)
Probabilistic Systems Analysis (MIT), Teaching Assistant ( Fall 2011, Fall 2012)
Some videos of me working problems appear in the Spring 2014 online course 6.041x as part of edX / MITx, and also in the Fall 2013 course 6.041SC as part of MIT's OCW initiative. You can also view videos from this online course on youtube!
Computing for Engineers -- MATLAB (Georgia Tech), Teaching Assistant (Fall 2007)
Last Modified: 2015/10/05, Erdös number = 4 :) [me -> J. N. Tsitsiklis -> K. Xu -> J. H. Spencer -> P. Erdös]