Personal Info
Affiliation: Silveregg Technology Email: kimikazu _at_ gmail.com
LinkedIn: http://linkedin.com/in/kimikazukato
SummaryI work as Chief Scientist at Silver Egg Technology. My main job is to design an algorithm to improve the accuracy of the existing recommender system for shopping sites. I specialize in machine learning, algorithms, and mathematical modeling.
I have been engaged in many kinds of projects in 10+ years of my career, but most of them are, to some extent, related to mathematics. I regard mathematics is the core of my skill.
Experience in  software design  algorithm design for geometric computation and data mining  technology consulting
Specialties:  algorithm design (especially for computational geometry and mathematical optimization)  numerical computation  mathematical modeling  hardware conscious performance tuning  GPGPU (General Purpose computing on GPU)  technical leadership especially about research planning  technical communication My Background While in Nihon Unisys, Ltd., engaged in:
 Customer analysis in direct marketing
 CAD system for industrial design
 Graphical presentation of CAD data
 Master's degree in mathematics, Ph.D in computer science
 Programming skills in Python, Haskell, Scala, C, C++, C#, Java, OCaml, VB, etc.
Recent presentations (Preparing) Papers
 K. Kato and T. Hosino. MultiGPU algorithm for knearest neighbor problem. Concurrency and Computation: Practice and Experience, 23, 2011.
 K.Kato, On Degeneracy of Lower Envelopes of Algebraic Surfaces, In Proc. Canadian Conference on Computational Geometry (CCCG2010), Winnipeg, Canada, 2010. [paper, ppt]
 K.Kato and T.Hosino, Singular Value Decomposition for Collaborative Filtering on a GPU, IOP Conference Series: Materials Science and Engineering 10 012017, 2010. [paper, ppt]
 K.Kato and T.Hosino, Solving kNearest Neighbor Problem on Multiple Graphics Processors, In Proc. The 10th IEEE/ACM International Symposium on Cluster, Cloud, and Grid Computing (CCGrid2010), Melbourne, Australia, pp 769773, 2010. [preprint]
 Kimikazu Kato, Mayumi Oto, Hiroshi Imai, and Keiko Imai, Computational Geometry Analysis of Quantum State Space and Its Applications, In "Generalized Voronoi Diagrams: StateoftheArt in Intelligent Treatment of Applied Problems", Studies in Computational Intelligence Vol. 158 Springer 2008.
 Kimikazu Kato, Hiroshi Imai, and Keiko Imai,
Smallest Enclosing Ball Problem in a Quantum State Space and Its Application,
In Proceedings of the 4th International Symposium on Voronoi Diagrams in Science and Engineering (ISVD08).
Kiev, Ukraine, 2008.
 Kimikazu Kato,
Voronoi Diagrams for Quantum States and Its Application to a Numerical Estimation of a Quantum Channel Capacity, Ph.D thesis, Universisy of Tokyo,
2008, http://arxiv.org/abs/0803.3109
 Kimikazu Kato, Mayumi Oto, Hiroshi Imai, and Keiko Imai,
Coincidence of Voronoi Diagrams in a Quantum State Space,
Asian Conference on Quantum Science (AQIS2007), Kyoto, Japan, 2007.
 Kimikazu Kato, Hiroshi Imai, and Keiko Imai,
Error Analysis of a Numerical Calculation about OneQubit Quantum Channel Capacity,
In Proceedings of the 4th International Symposium on Voronoi Diagrams in Science and Engineering (ISVD07), Wales, UK, Jul. 2007.
 Hidetoshi Muta and Kimikazu Kato,
Degeneracy of Angular Voronoi Diagram,
ISVD07, 2007, http://arxiv.org/abs/0710.0925
 Kimikazu Kato, Mayumi Oto, Hiroshi Imai, and Keiko Imai, Voronoi Diagrams and a Numerical Estimation of a Quantum Channel Capacity, In Proceedings of 2nd Doctoral Workshop on Mathematical and Engineering Methods in Computer Science (MEMICS 2006), Mikulov, Czech, Oct. 2006, arXiv:quantph/0611146.
 Jiro Nishitoba, Kimikazu Kato, Sonoko Moriyama, Hiroki Nakayama, and Hiroshi Imai,
Smallest Enclosing Balls and an Effective Calculation of a Quantum Channel Capacity, MEMICS 2006.
 Kimikazu Kato, Mayumi Oto, Hiroshi Imai, and Keiko Imai, On a Geometric Structure of Pure Multiqubit Quantum States and Its
Applicability to a Numerical Computation, In Proceedings of the 3rd International Symposium on Voronoi Diagrams in Science and Engineering, Banff, Canada, Jul. 2006, arXiv:quantph/0607029.
 Kimikazu Kato, Mayumi Oto, Hiroshi Imai, and Keiko Imai, Voronoi Diagrams for 1qubit Pure Quantum States, In Proceedings
of the 2nd International Symposium on Voronoi Diagrams, Seoul, Korea, Oct. 2005, arXiv:quantph/0604101.

