Nikolaos S. Sapidis

Professor

Industrial R&D and Software Development:

General Motors Design Center (1991-1993): Software Systems for Point-Cloud Processing, 

Surface Reconstruction, Curve/Surface Fairing. Related General Motors Research Publications:

N. Sapidis, P. Besl: Direct Construction of Polynomial Surfaces from Dense Range Images. GMR-AP-4, 1993.

 H. Burchard, J. Ayers, W. Frey, N. Sapidis: Approximation with Aesthetic Constraints. GMR-7814, 1993.

 N. Sapidis, W. Frey: Controlling the Curvature of a Quadratic Bezier Curve. GMR-7401, 1991.

NTUA/Ship-Design Laboratory/CAGD Group (1996-2001): Research and Software 

Development on  Solid Modeling and Processing of Complex Mechanical Systems,   in the framework of the Autodesk Developer Network. Related Publications:

 N. Sapidis and G. Theodosiou: Informationally-Complete Product Models of Complex Arrangements for Simulation-Based Engineering: Modeling Design-Constraints Using Virtual Solids. To appear in Engineering with Computers, 2001.

 N. Sapidis and G. Theodosiou: Planar Domain Simplification for Modelling Virtual Solids in Plant and Machinery Layout. Computer-Aided Design 31(10), pp. 597-610, 1999. 

Editorial Duties:

Member of Advisory Editorial Board of the journal  COMPUTER-AIDED DESIGN.

Member of the International Program Committee of the conferences:

COMPUTER GRAPHICS INTERNATIONAL '99, Calgary, June 7-11, 1999.
COMPUTER GRAPHICS INTERNATIONAL '98, Hannover, June 22-26, 1998.
PACIFIC GRAPHICS '98, Singapore, October 26-29, 1998. 

Member of the Local Organizing Committee of the conference:

10th INTERNATIONAL CONFERENCE ON COMPUTER APPLICATIONS IN SHIPBUILDING  (ICCAS'99),  MIT, Cambridge, MA, June 7-11, 1999.

Academic Service:

• Mathematics Department, University of Athens. Member of the Examination Committee of the Graduate Thesis of Efthimios Kapsalis (January 1999 - Present)
• Laboratoire d'Informatique Graphique Image et Modelisation, UFR d'Informatique, Universite Claude Bernard Lyon 1, France.  Member of the Examination Committee of the  Ph.D. Theses:
  1. "Segmentation d'ensembles non organises de points 3-D d'une surface: diffusion anisotrope basee sur les graphes" of Raphaelle Chaine (November 1999 - January 2000)
  2. "Segmentation des images de profondeur utilisant les analyses multiresolution" of Mourad Djebali (July-September 1998)

Referee and Review Activities:
 

Contributing Reviewer for the Journal  ACM: COMPUTING REVIEWS
Referee for the Journals: ACM: TRANS. ON GRAPHICS                       GRAPHICAL MODELS
COMPUTER-AIDED DESIGN		IEEE: COMPUTER GRAPHICS & APPLICATIONS
INTEGRATED CAE		IEEE: TRANS. VISUALIZATION & COMPUTER GRAPHICS
JOURNAL OF SHIP RESEARCH		COMPUTER AIDED GEOMETRIC DESIGN
THE VISUAL COMPUTER		ENGINEERING WITH COMPUTERS
COMPUTER GRAPHICS FORUM		J. OF COMPUTAT. & APPL. MATHEMATICS
Referee for the International Conferences:
6th ACM Symposium on Solid Modeling & Applications, Ann Arbor, USA, June 2001,  SMI2001 International Conference on Shape Modeling & Applications, Genoa, Italy, May 2001,  10th International Conference on Computer Applications in Shipbuilding, MIT, USA, June 1999,  Computer Graphics International Conference '99, Calgary, June 1999,  Computer Graphics International Conference '98, Hannover, June 1998,  Pacific Graphics '97 Conference, Seoul, Korea, October 1997,  13th Annual ACM Symposium on Computational Geometry, Nice, France, June 1997,  Fourth ACM/IEEE Symposium on Solid Modeling, Atlanta, USA, May 1997, Eurographics'96, Poitiers, France, August 1996, Computer Graphics International '96, Pohang, Korea, June 1996,  12th Annual Symposium on Computational Geometry, Philadelphia, USA, May 1996,  3rd ACM/IEEE Symposium on Solid Modeling, Salt Lake City, UT, USA, May 1995, etc.

Selected Refereed Publications:

 CAD/CAE: Algorithms, Software, and Systems 

• N. Sapidis & G. Theodosiou, ``Operational Constraints in Computer-Aided Ship Design: Modeling the Required "Virtual Solids"'', in Proceedings of The 10th International Conference on Computer Applications in Shipbuilding, Vol. I, Massachusetts Institute of Technology, Cambridge, USA 1999. 
• N. Sapidis, ``Variable-Order Surface Reconstruction Through Region Growing'', in CAD Systems Development: Tools and Methods, D. Roller & P. Brunet (eds), pp. 207-218, Springer, Germany 1997.
• N. Sapidis, ``Towards Automatic Shape Improvement of Curves and Surfaces for Computer Graphics and CAD/CAM Applications'', in Progress in Computer Graphics, C. Sabharwal & G. Zobrist (eds), pp. 216-253, Ablex, USA 1992.

Virtual Reality and Product Modeling for Complex Systems with Design Constraints 

• N. Sapidis & G. Theodosiou, ``Informationally-Complete Product Models of Complex Arrangements for Simulation-Based Engineering: Modeling Design-Constraints Using Virtual Solids'', to appear in Engineering with Computers, 2001.
• G. Farin & N. Sapidis, ``Shape Representation of Sculptured Objects: the Fairness of Curves and Surfaces'', in Automation in the Design and Manufacture of Large Marine Systems (MIT Sea Grant Program Seminar), Hemisphere, USA 1990.

Solid Modeling: Virtual Solids, Discrete Solid-Models 

• N. Sapidis & G. Theodosiou, ``Planar Domain Simplification for Modelling Virtual Solids in Plant and Machinery Layout'', Computer-Aided Design. 31(10), pp. 597-610, 1999.
• N. Sapidis & R. Perucchio, ``Solid/Solid Classification Operations for Recursive Spatial Decomposition and Domain Triangulation of Solid Models'', Computer-Aided Design 24(10), pp. 517-529, 1992.
• N. Sapidis & R. Perucchio, ``Domain Delaunay Tetrahedrization of Arbitrarily Shaped Curved Polyhedra Defined in a Solid Modeling System'', in Proceedings of the ACM/SIGGRAPH Symposium on Solid Modeling Foundations and CAD/CAM Applications, Austin, 1991.

Curve and Surface Design: Shape Preserving Interpolation, Fairing

•  N. Sapidis, I. Sarantidis, P. Kaklis, ``A Spline-in-Tension with a Parabolic Limit-Curve'', Proceedings of the International Workshop on ``Creating Fair and Shape Preserving Curves and Surfaces'' (Berlin, 1997, Organized by the Network FAIRSHAPE). 
• K. Pigounakis, N. Sapidis & P. Kaklis, ``Fairing Spatial B-spline Curves'', Journal of Ship Research 40(4), pp.351-367, 1996.
• P. Kaklis & N. Sapidis, ``Convexity-Preserving Interpolatory Parametric Splines of Non Uniform Polynomial Degree'', Computer Aided Geometric Design 12(1), pp. 1-26, 1995.

Computational (Discrete) Geometry 

• N. Sapidis & R. Perucchio, ``Domain Delaunay Tetrahedrization of Solid Models'', International Journal of Computational Geometry & Applications 1(3), pp. 299-325, 1991.
• N. Sapidis & R. Perucchio, ``Delaunay Triangulation of Arbitrarily Shaped Planar Domains'', Computer Aided Geometric Design 8(6), pp. 421-437, 1991. 

Computer Graphics and Visualization 

• N. Sapidis & G. Koras, ``Visualization of Curvature Plots and Evaluation of  Fairness: An Analysis of the Effect of Scaling'', Computer Aided Geometric Design 14(4), pp. 299-311, 1997.
• G. Farin & N. Sapidis, ``Curvature and the Fairness of Curves and Surfaces'', IEEE: Computer Graphics and Applications 9(2), pp. 52-57, 1989.

Finite Element Methods 

• N. Sapidis & R. Perucchio, ``Combining Recursive Spatial Decompositions and Domain Delaunay Tetrahedrizations for Meshing Arbitrarily Shaped Curved Solid Models'', Computer Methods in Applied Mechanics and Engineering 108(3), pp. 281-302, 1993.
• R. Perucchio & N. Sapidis, ``Solid/Solid Classification Operations for Automatic Meshing from Solid Models'', in Proceedings of the 1990 ASME Computers in Engineering Conference, Vol. I, pp. 53-60, Boston 1990.

Reverse Engineering using Computer Vision and CAD 

• N. Sapidis & P. Besl, ``Surface Reconstruction from Dense Point-Sets Using Image Processing Techniques'', Reverse Engineering, J. Hoschek & W. Dankwort (eds), pp. 133-141, Teubner, Germany 1996.
• N. Sapidis & P. Besl, ``Direct Construction of Polynomial Surfaces from Dense Range Images through Region Growing'', ACM: Transactions on Graphics 14(2), pp. 171-200, 1995.

Journal Special Issues:

• P.D. Kaklis, N.S. Sapidis, N.M. Patrikalakis (editors), Special Issue on Geometric Modeling Techniques, Mathematical Engineering in Industry, Volume 7, No. 2, 1999.
• P.D. Kaklis, N.S. Sapidis, N.M. Patrikalakis (editors), Special Issue on Reverse Engineering Techniques, International Journal of Shape Modeling, Volume 4, No. 3&4, 1998.

Books:

• P. Kaklis & N. Sapidis (editors), Computer Aided Geometric Design: From Theory to Practice, National Technical University of Athens, Greece 1995/96, ISBN 960-254-068-0.
• N. Sapidis (editor), Designing Fair Curves and Surfaces: Shape Quality in Geometric Modeling and CAD, Society for Industrial and Applied Mathematics (SIAM), USA 1994, ISBN 0-89871-332-3.

Major Invited Lectures:

• ``Designing with Volumes: An Approach to Facilitating Complex System Arrangement'', Seminar, Laboratoire d'Informatique Graphique, Images et Modelisation, UFR d'Informatique, Universite Claude Bernard Lyon 1, France, 24 January, 2000.
• ``Curves and Surfaces for Defining Geometric Models", Seminar, Mathematics Department, Aristotle University of Thessaloniki, Greece, December 15, 1998.
• ``Discrete Solid/Surface Models for Simplifying and Accelerating CAD/CAE Processes'', Seminar, F.B. Mathematik, Technical University of Darmstadt, Germany, Febr. 22, 1996.
• ``Hybrid Methods for Constructing Fair Curves and Surfaces in CAD'', Seminar, Mathematics Department, University of Crete, Greece, May 31, 1995.
• ``Collaboration of Solid Models with Discrete Models in CAD/CAM/CAE'', Seminar, Computer Science Department, University of Crete, Greece, May 30, 1995.
• ``Automatic Tetrahedrization of Solid Models for CAD/CAE'', Joint Design Laboratory (Ocean Engg.) and CADLAB (Mechanical Engg.) Seminar, MIT, USA, April 18, 1990.
• ``Automatic Tetrahedrization of Solid Models for CAD/CAE Applications'', Aries Technology, Inc., Lowell, MA, USA, April 17, 1990.
• ``An Efficient Fairing Method for B-spline Curves'', Computer Aided Geometric Design Seminars, Computer Science Department, Arizona State University, USA, April 16, 1987.

Invited Conference "Keynote Lecture":

• 7th ISPE International Conference on Concurrent Engineering: Research & Applications (CE2000), Sponsor: The International Society for Productivity Enhancement (ISPE), Lyon, France, 17/7/00 - 20/7/00.

Major Invited Conference/Workshop Presentations:

• Dagstuhl Seminar on CAD-Tools and Algorithms for Product Design, International Computer Science Research Center Schloss Dagstuhl, Germany, 15/11/98 - 20/11/98.
• International Workshop on ``Creating Fair and Shape-Preserving Curves and Surfaces'', Berlin, Germany, 14/9/97 - 17/9/97.
• Third Dagstuhl Seminar on Geometric Modeling, International Computer Science Research Center Schloss Dagstuhl, Wadern, Germany, 27/5/96 - 31/5/96.
• Second Workshop on Current CAX-Problems: Reverse Engineering - State of the Art & Solutions of System Vendors, Tauberbischofsheim, Germany, 26/2/96 - 29/2/96.
• Workshop on CAD Tools for Products, International Computer Science Research Center Schloss Dagstuhl, Wadern, Germany, 4/9/95 - 8/9/95.
• Second Dagstuhl Seminar on Geometric Modeling, International Computer Science Research Center Schloss Dagstuhl, Wadern, Germany, 28/6/93 - 2/7/93.
•  ASME Pressure Vessels & Piping Conference, New Orleans, LA,USA, 21/6/92 - 25/6/92.