Section: Partnerships and Cooperations

International Initiatives

INRIA Associate Teams

COMET

• Title: Computational Methods for the analysis of high-dimensional data

• INRIA principal investigator: Steve Y. Oudot

• International Partner:

  • Institution: Stanford University (United States)

  • Laboratory: Computer Science Department

  • Researcher: Leonidas J. Guibas

• International Partner:

  • Institution: Ohio State University (United States)

  • Laboratory: Computer Science and Engineering

  • Researcher: Yusu Wang

• Duration: 2011 - 2013

• See also: http://geometrica.saclay.inria.fr/collaborations/CoMeT/index.html

• CoMeT is an associate team between the Geometrica group at INRIA, the Geometric Computing group at Stanford University, and the Computational Geometry group at the Ohio State University. Its focus is on the design of computational methods for the analysis of high-dimensional data, using tools from metric geometry and algebraic topology. Our goal is to extract enough structure from the data, so we can get a higher-level informative understanding of these data and of the spaces they originate from. The main challenge is to be able to go beyond mere dimensionality reduction and topology inference, without the need for a costly explicit reconstruction. To validate our approach, we intend to set our methods against real-life data sets coming from a variety of applications, including (but not restricted to) clustering, image or shape segmentation, sensor field monitoring, shape classification and matching. The three research groups involved in this project have been active contributors in the field of Computational Topology in the recent years, and some of their members have had long-standing collaborations. We believe this associate team can help create new synergies between these groups.

DDGM

• Title: Discrete Differential Geometric Modeling

• INRIA principal investigator: Pierre Alliez

• International Partner:

  • Institution: California Institute of Technology (United States)

  • Laboratory: Applied Geometry Lab

• Duration: 2009 - 2011

• See also: http://www-sop.inria.fr/geometrica/collaborations/ddgm/

• Our initial goals were to collaborate on geometry processing and modeling. Our initial focus in 2009 was on the notion of quality of the computational models or discretizations: we carried out research on the generation of quality meshes through variational methods, on the generation of surface mesh parameterizations with low distortion, and on simplifications with guaranteed error bounds. The motivation was to meet the requirements imposed by simulations in computational engineering and computer animation. Amidst the completion of our project, we partially shifted our research goals when we realized that streamlining the geometry processing pipeline could be greatly facilitated if in addition to guaranteeing the output quality, we could provide robustness (i.e., resilience) to defect-laden inputs. This explains our recent focus on methods which are robust to heterogeneous data and to data hampered with a variety of defects. Sampling defects (such as non uniform, widely variable sampling, missing data) and uncertainty (noise, background noise, registration noise, outliers) are indeed increasingly present in datasets coming from cheaper and cheaper sensors. Our quest for ironclad robustness is best illustrated by two shape reconstruction methods we contributed, able to deal with noise and outliers.

OrbiCG

• Title: Triangulations and meshes in new spaces

• INRIA principal investigator: Monique Teillaud

• International Partner:

  • Institution: University of Groningen (Netherlands)

  • Laboratory: Johann Bernoulli Institute of Mathematics and Computing Science

• International Partner:

  • Institution: University of Groningen (Netherlands)

  • Laboratory: Kapteyn Astronomical Institute

• Duration: 2009 - 2011

• See also: http://www-sop.inria.fr/geometrica/collaborations/OrbiCG/

• Due to the now established emergence of standardized software libraries, such as the Computational Geometry Algorithms Library CGAL, a result of concerted efforts by groups of researchers in Europe, and whose Geometrica is one of the leaders, the so-far mostly theoretical results developed in computational geometry are being used and extended for practical use like never before for the benefit of researchers in academia and of industry. To fulfill the promise of applicability of computational geometry and to expand the scope of initial efforts, extending the traditional focus on the Euclidean space Rd ("urbi") to encompass various spaces ("orbi") has become important and timely.

Visits of International Scientists

Exterior research visitors

• Alla Sheffer, University of British Columbia, one week in March

• David Bommes, RWTH Aachen, one week in June

• Konstantin Mischaikow Rutgers University, 6 weeks in June-July

• Vin de Silva Pomona College, one month in June

• Mathieu Desbrun, Caltech, one week in July

• Tetsuo Asano, Japan Advanced Institute of Science and Technology, one week in September

• Jian Sun (Tsinghua University, Pékin), two weeks, September.

• Gert Vegter, Institute of Mathematics and Computing Science, University of Groningen, NL, three weeks in October

• Pratyush Pranav, Kapteyn Astronomical Institute, University of Groningen, NL, two weeks in October

• Mathijs Wintraecken, Institute of Mathematics and Computing Science, University of Groningen, NL, two weeks in October

• Rien van de Weijgaert, Kapteyn Astronomical Institute, University of Groningen, NL, two weeks in October

Visiting Phd students

• Kan-Le Shi, Tsinghua University Beijing, 4 months.