I am a project assistant professor at "FIRST, Aihara Innovative Mathematical Modelling Project"

From April 2008 to August 2010, I was a postdoc at CompView at Tokyo Tech.

I received a PhD in information science and technology from University of Tokyo in March 2008.

- Matroids, Submodular Functions, Discrete Convex Analysis
- Approximation Algorithms
- Convex Optimization
- Machine Learning

- Kiyohito Nagano, and Yoshinobu Kawahara and Kazuyuki Aihara:

Size-constrained submodular minimization through minimum norm base.

In Proceedings of the 28th International Conference on Machine Learning (ICML 2011), pp. 977-984.

- Yoshinobu Kawahara, Kiyohito Nagano, and Yoshio Okamoto:

Submodular fractional programming for balanced clustering.

*Pattern Recognition Letters*, 32 (2011), pp. 235-243.

- Kiyohito Nagano, Yoshinobu Kawahara, and Satoru Iwata:

Minimum average cost clustering.

In Advances in Neural Information Processing Systems 23 (NIPS 2010), pp. 1759-1767.

- Yoshinobu Kawahara, Kiyohito Nagano, Koji Tsuda, and Jeff Bilmes:

Submodularity Cuts and Applications.

In Advances in Neural Information Processing Systems 22 (NIPS 2009), pp. 916-924.

- Satoru Iwata and Kiyohito Nagano:

Submodular function minimization under covering constraints.

In Proceedings of the 50th Annual Symposium on Foundations of Computer Science (FOCS 2009), pp. 671-680.

- Satoru Fujishige and Kiyohito Nagano:

A structure theory for the parametric submodular intersection problem.

*Mathematics of Operations Research*, 34 (2009), pp. 513-521.

- Satoru Fujishige, Takumi Hayashi, and Kiyohito Nagano:

Minimizing discrete convex functions with linear inequality constraints.

*SIAM Journal on Optimization*, 20 (2009), pp. 856-867.

- Kiyohito Nagano:

On convex minimization over base polytopes.

In Proceedings of the 12th IPCO Conference, Lecture Notes in Computer Science, LNCS 4513, Springer-Verlag (2007), pp. 252-266. - Fabián Chudak and Kiyohito Nagano:

Efficient solutions to relaxations of combinatorial problems with submodular penalties via the Lovász extension and non-smooth convex optimization.

In Proceedings of the 18th ACM-SIAM Symposium on Discrete Algorithms (SODA 2007), pp. 79-88. - Kiyohito Nagano:

A strongly polynomial algorithm for line search in submodular polyhedra.

*Discrete Optimization*4 (2007), pp. 349-359.

- Kiyohito Nagano:

A faster parametric submodular function minimization algorithm and applications.

Mathematical Engineering Technical Reports, METR 2007-43, University of Tokyo, July 2007.