I am an assistant professor in the Grado Department of Industrial and Systems Engineering (ISE) at Virginia Tech. I obtained my PhD at the University of California, Davis under the supervision of Matthias Köppe. Afterwards, I spent two years in Zurich, Switzerland as a postdoctoral researcher at the Institute for Operations Research in the Department for Mathematics at ETH Zurich. Subsequently, I was a Goldstine Fellow Postdoctoral Researcher at IBM Watson Research Center in Yorktown Heights, New York. In 2017, I participated in the semester-long Simons Institute program on Bridging Continuous and Discrete Optimization at UC Berkeley.
E-mail: rhil@vt.edu
Mixed-Integer Nonlinear Optimization
Cutting Plane Theory and Practice
Convex Analysis and Discrete Geometry
Complexity
Operations Research
Redistricting
Ph.D. in Applied Mathematics, University of California, Davis, June 2013
B.Sc. in Mathematics, University of Puget Sound, May 2008
Air Force Office of Scientific Research - Young Investigator Program
1.5.25
Aussois! I'm speaking at the Combinatorial Optimization Workshop in Aussois, France on our recent work Complexity of integer programming in reverse convex sets via boundary hyperplane cover.
12.20.24
Seed Funding! Together with Junghwan Kim and Mengxi Zhang, we received $40,000 from the Whole Health Consortium at Virginia Tech to start work on our project Geospatial Analysis and Optimization for Veterans’ Healthcare Access in Pain Management.
10.18.24
Thesis Defense! Congratulations to Jamie Fravel for completing his thesis defense!
7.21.24
ISMP! WI will be speaking about complexity in mixed integer nonlinear programming at a session at the International Symposium on Mathematical Programming in Montreal in July. I'm also organizing a session on Advances in Mixed Integer Programming theory.
7.9.24
Preprint! Work with Adrian Göß, Complexity of integer programming in reverse convex sets via boundary hyperplane cover, 2024. arXiv: 2409.05308 [math.OC]. [Online]. Available: https://arxiv.org/abs/2409.05308.
7.5.24
Preprint! Work with my student, Jamie Fravel Automating idealness proofs for binary programs with application to rectangle packing, 2024. arXiv: 2407.04867 [math.OC]. [Online]. Available: https://arxiv.org/abs/2407.04867.
6.2.24
Summer School Lecture! With Dr. Santanu Dey and Dr. Phillip Richard, we will be giving a summer school session on Cutting Planes prior to the Mixed Integer Programming Workshop, 2024.
2.7.24
Paper Accepted! With Dr. Nicholas Goedert, Dr. Laurel Travis, and Matthew Pierson, our paper "Asymmetries in Potential for Partisan Gerrymandering" has been published in Legislative Studies Quarterly. See the paper here.
1.30.24
Paper Accepted! With Dr. Ben Beach (former student), Lukas Hager, Robert Burlacu, and Andreas Barman, our paper Enhancements of Discretization Approaches for Non-Convex Mixed-Integer Quadratically Constraint Quadratic Programming Part I is published in Computational Optimization and Applications. This paper handles new techniques for discretizing quadratics. Part II will be available shortly.
10.25.23
Paper Accepted! With Dr. Ben Beach (former student), William Chapin, Samantha Chapin, and Dr. Erik Komendera, our paper "Force-Controlled Pose Optimization and Trajectory Planning for Chained Stewart Platforms" has been approved for production and accepted for publication in Frontiers in Mechanical Engineering, section Digital Manufacturing.
This paper uses quadratically constrained quadratic programming to optimize robotics movements developed in the FASER lab.
10.17.23
INFORMS Presentation! Graduate student Hyunwoo Lee of Virginia Tech spoke at the INFORMS annual conference on our work Integer Programming Games for Invasive Species Prevention. This is joint work Dr. Esra Toy and Dr. Selina Cai. Preprint will be available soon!
10.12.23
Seed Grant! With Dr. Erik Komendera, we were awarded the Virginia Tech ICTAS EFO-O Seed Grant for 2023 (FY24) for our grant proposal: Optimizing Autonomous Fleets: Algorithms for Space Exploration.
This work involves mixed-integer optimization, optimization under uncertainty, online optimization, machine learning and artificial intelligence.
8.14.23
Continuation Grant! With Dr. Esra Buyuktahtakin Toy, Dr. Wenbo Selina Cai and Dr. Amy Kinsley, we were awarded a continuation grant by .Minnesota Aquatic Invasive Species Research Center for our project: County collaborations for watercraft inspection planning.
This work involves mixed-integer optimization, game theory, and mechanism design.
List of collaborators:
Amitabh Basu, Jörg Bader, Lebron Baptiste, Benjamin Beach, Daniel Beinstock, Robert Burlacu, Samantha Chapin, William Chapin, Stephen R. Chestnut, Sanjeeb Dash, Alberto Del Pia, Kimberly Ellis, Jamie Fravel, Nicholas Goedert, A. G ̈oß, Oktay Günlük, Lukas Hagar, Julia Hoffman, Joey Huchette, Erik Komendera, Matthias Köppe, Marco Molinaro, Joshua Moser, Timm Oertel, Laurel Travis, Robert Weismantel, Kevin Zemmer, Rico Zenklusen, Yuan Zhou,
Former graduate students:
Brannon King. MS (CS). 2024.
Jamie Fravel. PhD (ISE). 2024. Thesis: Embeddings for Disjunctive Programs with Applications to Political Districting and Rectangle Packing
Benjamin Beach. PhD (ISE). 2022. Thesis: Discrete Approximations, Relaxations, and Applications in Quadratically Constrained Quadratic Programming