Department of Computer Science & Engineering Home Address: University of North Texas 1700 Kendolph Denton, TX 76203-1366 Denton, TX 76205 (940) 565-2816 (940) 566-5487 email: robert.renka@unt.edu EDUCATION: Year Degree Major Institution 1981 Ph.D. Computer Science University of Texas, Austin 1979 MA in Mathematics Mathematics University of Texas, Austin 1976 BS in Mathematics Mathematics University of Texas, Austin 1976 BA with High Honors Computer Science University of Texas, Austin PROFESSIONAL EXPERIENCE: Dates Position Organization Location 1999- Professor Univ. of North Texas Denton, TX 1989-1999 Associate Professor Univ. of North Texas Denton, TX 1984-1989 Assistant Professor Univ. of North Texas Denton, TX 1981-1984 Numerical Analyst Oak Ridge Natl. Lab. Oak Ridge, TN 1976-1981 Research Assistant University of Texas Austin TX PROFESSIONAL ACTIVITIES: Offices in Professional Organizations: Editor-in-Chief of Collected Algorithms from the ACM (1989 to 1994) Algorithms Editor of ACM Trans. Mathematical Software (1988 to 1994) Other Activities: Referee for journal articles and NSF grant proposals Consulting: Formal Systems Design & Development, Inc., United States Coast Guard, Applied Geophysical Software, Inc., Oak Ridge National Laboratory, J. S. Nolen & Associates, National Security Agency HONORS: Listed in American Men and Women of Science, Who's Who in America, Who's Who in American Education, Who's Who in Finance and Industry, Who's Who in Science and Engineering, Who's Who in the South and Southwest, and Who's Who in the World AREAS OF EXPERTISE: Computational Geometry Numerical Solution of Partial Differential Equations Curve and Surface Fitting UNIVERSITY COMMITTEES: Jan 2013 to present Oversight Committee on the Core Curriculum Sep 2006 to Sep 2009 Faculty Development Leave Committee Sep 2004 to Sep 2009 Faculty Workload subcommittee of Faculty Senate Sep 1992 to May 1998 Graduate Council Sep 1985 to Aug 1991 Federation of North Texas Area Universities, Computer Science Committee COLLEGE COMMITTEES: Sep 2012 to present Undergraduate Curriculum Committee Sep 2012 to present College of Engineering Scholarship Committee Sep 2009 to Aug 2010 College of Engineering PAC Sep 2005 to Aug 2007 Engineering Technology PAC Sep 2003 to Dec 2003 Materials Science P&T Committee Sep 1989 to Aug 1992 Graduate Curriculum Committee Jan 1988 to Dec 1989 Dean's Representative, University Computing Council, Academic Administrative Advisory Group DEPARTMENT COMMITTEES: Sep 2006 to present Personnel Affairs Committee Sep 2012 to present Undergraduate Committee (chair) Sep 2010 to Aug 2012 Undergraduate Committee Sep 2008 to present Executive Committee Sep 2010 to Aug 2010 Promotion Committee (chair) Sep 2007 to Sept 2009 Graduate Committee Sep 2007 to Aug 2008 Faculty Search Committee Sep 2006 to Aug 2007 Undergraduate Committee Jan 2005 to Aug 2006 Personnel Affairs Committee (chair) Sep 2005 to Aug 2006 Graduate Committee Sep 2003 to Aug 2005 Undergraduate Committee Sep 2004 to Dec 2004 Personnel Affairs Committee Sep 2002 to Aug 2004 Executive Committee Sep 2000 to Aug 2003 Personnel Affairs Committee Jan 2002 to Aug 2002 Faculty Search Committee (chair) Sep 1995 to Aug 2002 Undergraduate Committee (chair) Sep 2001 to Dec 2001 Faculty Search Committee Jan 2001 to Aug 2001 Chair Search Committee (chair) Aug 1994 to Aug 2001 Executive Committee Sep 1999 to Aug 2000 Personnel Affairs Committee (chair) Sep 1997 to Aug 1998 Personnel Affairs Committee Jan 1997 to Aug 1997 Graduate Committee Jan 1996 to Aug 1996 Personnel Affairs Committee Sep 1995 to Aug 1996 Graduate Committee Sep 1992 to Aug 1995 Personnel Affairs Committee Sep 1991 to Aug 1993 Faculty Search Committee (chair) Sep 1991 to Aug 1992 Graduate Committee Sep 1989 to Aug 1991 Personnel Affairs Committee (chair) Sep 1987 to Aug 1991 Executive Committee Jan 1988 to Dec 1988 Faculty Search Committee Jan 1988 to Dec 1988 Chairman Search Committee Jan 1985 to Aug 1987 Research Committee (chair) Sep 1985 to Dec 1986 Graduate Committee FUNDED GRANTS: 2008- "Digital Image Interpolation and Analysis in the Presence of Noise and Artifacts", with S. Betelu, R. Kallman, and J. W. Neuberger, National Security Agency, $72,750. 2000-2001 "Superconductivity Simulations", with J. W. Neuberger, National Security Agency, $27,350. 1999-2000 "Simulation of Superconductivity for Crossbar", with J. W. Neuberger, National Security Agency, $24,994. 1993 "Snowflake Harmonics", with J. W. Neuberger, Cornell Theory Center, 10 service units on the supercomputer facility. 1991-1993 "Software for Scattered Data Fitting with a Constrained Surface under Tension", National Science Foundation, $98,057. 1990-1991 "Software for Curve Fitting with Exponential Tension Splines", National Science Foundation, $42,997. 1989 "A Three-dimensional Constrained Delaunay Triangulation", University of North Texas, $3800. 1988-1989 "Nonlinear estimation techniques applied to exoatmospheric homing missile engagements", Formal Systems Design & Development, Inc, $9,000. 1988-1989 "Numerical methods and software for ray tracing", Applied Geophysical Software, Inc., $35,046. 1988 "Constrained Surface Fitting", University of North Texas, $3200. 1987 "A Smoothing Surface Based on Shepard's Method", University of North Texas, $3200. 1986 "Software for Curve Fitting with Tension Splines", University of North Texas, $1500. 1985 "Scattered Data Smoothing", University of North Texas, $3700. 1984 "Scattered Data Interpolation with a Surface Under Tension", University of North Texas, $4500. REFEREED JOURNAL ARTICLES: A. K. Cline and R. J. Renka, A storage-efficient method for construction of a Thiessen triangulation, Rocky Mountain J. Math., 14, Winter 1984, pp. 119-139. R. J. Renka and A. K. Cline, A triangle-based C1 interpolation method, ocky Mountain J. Math., 14, Winter 1984, pp. 223-237. R. J. Renka, Interpolation of data on the surface of a sphere, ACM Trans. Math. Software, 10, 4, December 1984, pp. 417-436. R. J. Renka, ALGORITHM 623: Interpolation on the surface of a sphere, ACM Trans. Math. Software, 10, 4, December 1984, pp. 437-439. R. J. Renka, ALGORITHM 624: Triangulation and interpolation at arbitrarily distributed points in the plane, ACM Trans. Math. Software, 10, 4, December 1984, pp. 440-442. D. W. Noid, S. K. Knudson, M. L. Koszykowski, and R. J. Renka, Semiclassical calculation of molecular vibrations from ab initio potentials using splines: ozone, J. Physical Chemistry, 90, 1986, pp. 6135-6138. R. J. Renka, Interpolatory tension splines with automatic selection of tension factors, SIAM J. Sci. Stat. Comp., 8, 3, May, 1987, pp. 393-415. [download Postscript file] R. J. Renka, Multivariate interpolation of large sets of scattered data, ACM Trans. Math. Software, 14, 2, June 1988, pp. 139-148. R. J. Renka, ALGORITHM 660. QSHEP2D: Quadratic Shepard method for bivariate interpolation of scattered data, ACM Trans. Math. Software, 14, 2, June 1988, pp. 149-150. R. J. Renka, ALGORITHM 661. QSHEP3D: Quadratic Shepard method for trivariate interpolation of scattered data, ACM Trans. Math. Software, 14, 2, June 1988, pp. 151-152. R. J. Renka and F. Vest, Graphical representation of complex functions, Mathematics and Computer Education, 22, 1, Winter 1988, pp. 33-45. J. F. Fohlmeister, R. J. Renka, and J. H. Stout, Lithospheric plate motions predicted by a quantitative theory, Transactions of the American Geophysical Union, Vol. 71, No. 43, October 1990, p. 1630. A. K. Cline and R. J. Renka, A constrained two-dimensional triangulation and the solution of closest node problems in the presence of barriers, SIAM J. Numerical Analysis, 27, 5, October 1990, pp. 1305-1321. R. J. Renka and A. K. Cline, Scattered data fitting using a constrained Delaunay triangulation, IMACS Transactions on Scientific Computing 91 Volume 3: AI, Expert Systems, and Symbolic Computation, North Holland, June 1992. R. J. Renka, ALGORITHM 716. TSPACK: Tension spline curve fitting package, ACM Trans. Math. Software, 19, 1, March 1993, pp. 81-94. [download Postscript file] J. F. Fohlmeister and R. J. Renka, Hotspots, mantle convection and plate tectonics: a synthetic calculation, Pure and Applied Geophysics, 143, 4, 1994, pp. 673-695. R. J. Renka and J. W. Neuberger, Minimal surfaces and Sobolev gradients, SIAM J. Sci. Comput., 16, 6, November 1995, pp. 1412-1427. R. J. Renka, ALGORITHM 751. TRIPACK: Constrained two-dimensional Delaunay triangulation package, ACM Trans. Math. Software, 22, 1, March 1996, pp. 1-8. R. J. Renka, ALGORITHM 752. SRFPACK: Software for scattered data fitting with a constrained surface under tension, ACM Trans. Math. Software, 22, 1, March 1996, pp. 9-17. M. L. Lapidus, J. W. Neuberger, R. J. Renka, and C. A. Griffith, Snowflake harmonics and computer graphics: numerical computation of spectra on fractal drums, International Journal of Bifurcation and Chaos in Applied Sciences and Engineering, 6, 7, 1996, pp. 1185-1210. J. W. Neuberger and R. J. Renka, Numerical calculation of singularities for Ginzburg-Landau functionals, Electr. J. Diff. Eqns., 1997, 10, June 1997, pp. 1-4. [download Postscript file] R. J. Renka, ALGORITHM 772. STRIPACK: Delaunay triangulation and Voronoi diagram on the surface of a sphere, ACM Trans. Math. Software, 23, 3, Sept. 1997, pp. 416-434. R. J. Renka, ALGORITHM 773. SSRFPACK: Interpolation of scattered data on the surface of a sphere with a surface under tension, ACM Trans. Math. Software, 23, 3, Sept. 1997, pp. 435-442. J. F. Fohlmeister and R. J. Renka, Fracture of a superplate: the proximal cause of the Hawaiian-emperor seamount bend?, Pure and Applied Geophysics, 151, 1998, pp. 119-146. J. W. Neuberger and R. J. Renka, Sobolev gradients and the Ginzburg- Landau functional, SIAM J. Sci. Comp., 20, 2, 1998, pp. 582-590. [download Postscript file] R. J. Renka and R. Brown, Remark on Algorithm 761, ACM Trans. Math. Software, 24, 4, Dec. 1998, pp. 383-385. R. J. Renka, Algorithm 790. CSHEP2D: Cubic Shepard method for bivariate interpolation of scattered data, ACM Trans. Math. Software, 25, 1, Mar. 1999, pp. 70-73. R. J. Renka and R. Brown, Algorithm 791. TSHEP2D: Cosine series Shepard method for bivariate interpolation of scattered data, ACM Trans. Math. Software, 25, 1, Mar. 1999, pp. 74-77. R. J. Renka and R. Brown, Algorithm 792. Accuracy tests of ACM algorithms for interpolation of scattered data in the plane, ACM Trans. Math. Software, 25, 1, Mar. 1999, pp. 78-94. F. J. Testa and R. J. Renka, Remark on Algorithm 716, ACM Trans. Math. Software, 25, 1, Mar. 1999, pp. 95-96. R. J. Renka, Remark on Algorithm 751, ACM Trans. Math. Software, 25, 1, Mar. 1999, pp. 97-98. R. J. Renka, Remark on Algorithm 752, ACM Trans. Math. Software, 25, 1, Mar. 1999, pp. 99-100. N. K. Leung and R. J. Renka, C1 convexity-preserving interpolation of scattered data, SIAM J. Sci. Comput., 20, 5, May 1999, pp. 1732-1752. [download Postscript file] J. W. Neuberger and R. J. Renka, Numerical calculation of the essential spectrum of a Laplacian, Experimental Math., 8, 3, Sep. 1999, pp. 301-308. [download Postscript file] C. Zoppou, S. Roberts, and R. J. Renka, Exponential spline interpolation in characteristic based scheme for solving the advective-diffusion equation, Int. J. Num. Meth. Fluids, 33, 3, June, 2000, pp. 429-452. J. W. Neuberger and R. J. Renka, Critical points of the Ginzburg- Landau functional on multiply-connected domains, Experimental Math., 9, 4, winter 2000, pp. 523-533. [download Postscript file] J. W. Neuberger and R. J. Renka, Numerical approximation of critical points of the Ginzburg-Landau functional, J. Nonlinear Analysis, 47, 2001, pp. 3259-3270. [download Postscript file] J. F. Fohlmeister and R. J. Renka, Distribution of mantle up-welling determined from plate motions: a case for large-scale Benard convection, Pure and Applied Geophysics, 159, 11-12, 2002, pp. 2585-2612. J. W. Neuberger and R. J. Renka, Computational simulation of vortex phenomena in superconductors, Electronic Journal of Differential Equations, Conference 10, 2003, pp. 241-250. [download pdf file] R. J. Renka, Algorithm 828. DNSPLIN1: Discrete nonlinear spline interpolation, ACM Trans. Math. Software, 29, 4, Dec. 2003, pp. 1-11. J. W. Neuberger and R. J. Renka, Numerical determination of vortices in superconductors: simulation of cooling, Superconductor Science and Technology, 16, 12, 2003, pp. 1413-1416. [download pdf file] R. J. Renka, Constructing fair curves and surfaces with a Sobolev gradient method, Computer Aided Geometric Design, 21, 2, 2004, pp. 137-149. Pawel A. Penczek, Robert Renka, and Hermann Schomberg, Gridding-based direct Fourier inversion of the three-dimensional ray transform, J. Opt. Soc. Am. A, 21, 4, April 2004, pp. 499-509. R. J. Renka, Algorithm 833: CSRFPACK -- Interpolation of scattered data with a C^1 convexity-preserving surface, ACM Trans. Math. Software, 30, 2, June 2004, pp. 200-211. [download pdf file] R. J. Renka, Algorithm 834: glsurf -- An interactive surface plotting program using OpenGL, ACM Trans. Math. Software, 30, 2, June 2004, pp. 212-217. [download pdf file] J. W. Neuberger and R. J. Renka, Sobolev gradients: introduction, applications, problems, Contemporary Mathematics, 357, 2004, pp. 85-99. Peter M. Lyster, Stephen E. Cohn, Banglin Zhang, Lang-ping Chang, Richard Menard, Kevin Olson, and Robert Renka, A Lagrangian trajectory filter for constituent data assimilation, Quarterly Journal of the Royal Meteorological Society, 130, July 2004, Part B, No. 601, pp. 2315-2334. J. W. Neuberger and R. J. Renka, Least squares and chaotic behavior in initial value problems, J. Nonlinear and Convex Analysis, 6, 1, 2005, pp. 65-70. R. J. Renka, A Sobolev gradient method for construction of elastic curves in regular surfaces, J. Nonlinear Analysis: Theory, Methods and Applications, 63, 2005, pp. e1789-e1796, doi: 10.1016/ j.na.2005.02.101. A. Linner and R. J. Renka, Discrete periodic geodesics in a surface, Experimental Math., 14, 2, 2005, pp. 145-152. R. J. Renka, Shape-preserving interpolation by fair discrete G3 space curves, Computer Aided Geometric Design, 22, No. 8, 2005, pp. 793-809, doi: 10.1016/j.cagd.2005.03.003. R. J. Renka, Curve fitting with a Sobolev gradient method, Proceedings in Applied Mathematics and Mechanics, 7, 1, December 2007, pp. 1025503-1025504. R. J. Renka, Image segmentation with a Sobolev gradient method, J. Nonlinear Analysis: Theory, Methods and Applications, 71, 12, 2009, pp. e774-e780, doi: 10.1016/j.na.2008.11.070. [download pdf file] R. J. Renka, Algorithm 893: TSPACK: Tension spline package for curve design and data fitting, ACM Trans. Math. Softw. 36, 1, Article 7 (February 2009), 8 pages. DOI = 10.1145/1486525.1486532 http://doi.acm.org/10.1145/1486525.1486532 P. Kazemi and R. J. Renka, A Levenberg-Marquardt method based on Sobolev gradients, Nonlinear Analysis Series A: Theory, Methods & Applications, 75, 2012, pp. 6170-6179, http://dx.doi.org/10.1016/ j.na.2012.06.022. [download pdf file] P. Kazemi and R. J. Renka, Minimization of the Ginzburg-Landau energy functional by a Sobolev gradient trust-region method, Appl. Math. Comput., 219, 11, 2013, pp. 5936-5942, http://dx.doi.org/10.1016/ j.amc.2012.12.038. [download pdf file] R. J. Renka, Nonlinear least squares and Sobolev gradients, Applied Numerical Mathematics, 65, 2013, pp. 91-104, http://dx.doi.org/ 10.1016/j.apnum.2012.12.002. [download pdf file] R. J. Renka, A Sobolev gradient method for treating the steady-state incompressible Navier-Stokes equations, Cent. Eur. J. Math., 11 (2013), 630-641, http://dx.doi.org/10.2478/s11533-013-0201-4. [download pdf file] I. Knowles and R. J. Renka, Methods for numerical differentiation of noisy data, Electron. J. Diff. Eqns., Conference 21 (2014), pp. 235-246. [download pdf file] P. Kazemi and R. J. Renka, Tikhonov regularization and Sobolev metrics, Electron. J. Diff. Eqns., Conference 21 (2014), pp. 173-181. [download pdf file] R. J. Renka, A trust region method for constructing triangle-mesh approximations of parametric minimal surfaces, Applied Numerical Mathematics, 76C (2014), pp. 93-100, http://dx.doi.org/10.1016/ j.apnum.2013.10.006. [download pdf file] R. J. Renka, Mesh improvement by minimizing a weighted sum of squared element volumes, International Journal for Numerical Methods in Engineering, 101 (2015), pp. 870-886. [download pdf file] R. J. Renka, Two simple methods for improving a triangle mesh surface, Computer Graphics Forum, 35 (2016), pp. 46-58. [download pdf file] R. J. Renka, A simple and efficient method for modeling constant mean curvature surfaces, SIAM J. Sci. Comput. 37 (2015), pp. A2076-A2099. [download pdf file] REFEREED CONFERENCE PROCEEDINGS: G. F. Carey, T. T. Pan, and R. J. Renka, Two problems in nonlinear finite element analysis, Applied Nonlinear Analysis, V. Lakshmikantham, Ed., Academic Press, pp. 467-477, 1979. R. J. Renka, PDE2D: A nonlinear PDE solver, Sparse Matrix Symposium 1982 Software Catalog, October 1982, p. 120. R. J. Renka and A. K. Cline, Scattered data fitting using a con- strained Delaunay triangulation, Proceedings of the 13th IMACS World Congress on Computation and Applied Mathematics, July 22-26, 1991, Dublin, Ireland, Vol. 1, pp. 122-123 (invited). J. W. Neuberger and R. J. Renka, Approximation of eigenvalues of the Dirichlet Laplacian on a fractal drum, Proceedings of the Third IMACS International Symposium on Iterative Methods in Scientific Computation, July 9-12, 1997, Jackson Hole, Wyoming. J. W. Neuberger and R. J. Renka, Numerical determination of vortices in superconductors with holes: simulation of cooling, International Superconducting Electronics Conference, July 7-11, 2003, Sydney, Australia. Pawel Penczek, Robert Renka, and Hermann Schomberg, Gridding-based three-dimensional image reconstruction from projections with arbitrary directions, IEEE International Symposium on Biomedical Imaging, April 15-18, 2004, Arlington, Virginia. REFEREED POSTER SESSION: S. B. Johnson and R. J. Renka, Triangle mesh generation by edge splitting and angle-based smoothing, Posters, 25th International Meshing Roundtable, Sandia National Laboratories, September 26-30, 2016. BOOK CHAPTER: R. J. Renka, Geometric Curve Modeling with Sobolev Gradients, in J. W. Neuberger, Sobolev Gradients and Differential Equations, Springer Lecture Notes in Mathematics 1670, 2010, pp. 199-208. TECHNICAL REPORTS: G. F. Carey and R. J. Renka, Nonlinear Membrane Analysis, Texas Institute for Computational Mechanics Report # TICOM 79-1, May 1979. J. W. Neuberger and R. J. Renka, A Portable Software Package for Nonlinear Partial Differential Equations, Oak Ridge National Laboratory, Report # ORNL/CSD-102, March 1982. R. J. Renka, A Storage-efficient Method for Construction of a Thiessen Triangulation, Oak Ridge National Laboratory, Report # ORNL/CSD-101, April 1982. R. J. Renka, A Triangle-based C-1 Interpolation Method, Oak Ridge National Laboratory, Report # ORNL/CSD-103, April 1982. R. J. Renka, Interpolation of Data on the Surface of a Sphere, Oak Ridge National Laboratory, Report # ORNL/CSD-108, October 1983. R. J. Renka, A Low Level Fortran Graphics Package for the IBM PC, NTSU Dept. of Computer Sciences Technical Notes Series # NT86-001, February 1986. C. Zoppou, S. Roberts, and R. J. Renka, Exponential Interpolation in Characteristic Based Scheme for Solving the Advective-Diffusion Equation, Australian National University Mathematics Research Report No. MRR 039-97, October 1997. P. M. Lyster, B. Zhang, R. Menard, K. Olson, L. P. Chang, R. Renka, T. Janjic, and S. E. Cohn, A Lagrangian Trajectory Filter for Constituent Data Assimilation, Data Assimilation Office, Goddard Space Flight Center, DAO Office Note 00-XX, January 1, 2000. J. F. Fohlmeister and R. J. Renka, Distribution of Mantle Up-welling Determined from Plate Motions: A Case for Large-scale Benard Convection, University of Minnesota Supercomputing Institute Research Report UMSI 2000/250, December 2000. J. F. Fohlmeister, Hsin-ching Lin, and R. J. Renka, Nucleation and Accretion of Proto-continents and the Origin of Continental Drift: a Model Mechanism, University of Minnesota Supercomputing Institute Research Report UMSI 2004/25, February 2004. Parimah Kazemi and Robert Renka, Nonlinear Optimization in Hilbert Space using Sobolev Gradients with Applications, Ulmer Seminaire, Vol 17, 2012. PAPERS PRESENTED: R. J. Renka, Triangulation and Bivariate Interpolation for Irregular- ly Distributed Data Points, SIAM 1980 Fall meeting, November 6-8, 1980, Houston, Texas. R. J. Renka and J. W. Neuberger, A Portable Software Package for Nonlinear Partial Differential Equations, a) 1982 NASIG meeting, June 23-25, 1982, Los Alamos National Laboratory, Los Alamos, New Mexico. b) SIAM 30th Anniversary Meeting, July 19-23, 1982, Stanford University, Stanford, California. c) Sparse Matrix Symposium 1982, October 24-27, 1982, Fairfield Glade, Tennessee. R. J. Renka and A. K. Cline, A Triangle-Based C-1 Interpolation Method, SIAM 30th Anniversary Meeting, July 19-23, 1982, Stanford University, Stanford, California. A. K. Cline and R. J. Renka, The Generation of a Triangular Grid to Given Nodes Arbitrarily Distributed in the Plane, SIAM 30th Anniversary Meeting, July 19-23, 1982, Stanford University, Stanford, California. R. J. Renka, A Practical Guide to Curve and Surface Fitting, Center for Applied Mathematics Seminar, March 22, 1984, National Bureau of Standards, Gaithersburg, Maryland (invited). R. J. Renka, Automatic Selection of Tension for Curve Fitting with Tension Splines, Third Regional Conference on Numerical Analysis, September 28-29, 1984, North Texas State University, Denton, Texas. R. J. Renka, A New Method for Automatic Finite Element Mesh Genera- tion in Two Dimensions, 1986 Texas Seminar in Differential Equations, April 19, 1986, North Texas State University, Denton, Texas. A. K. Cline and R. J. Renka, A Generalized Delaunay Triangulation, SIAM 1986 National Meeting, July 21-25, 1986, Boston Park Plaza Hotel, Boston, Mass. A. K. Cline and R. J. Renka, Scattered Data Interpolation with Surface Discontinuities or Missing Data, SIAM 1986 National Meeting, July 21-25, 1986, Boston Park Plaza Hotel, Boston, Mass. R. J. Renka, Fitting Curves and Surfaces to Discrete Data Sets, Physics Colloquium, October 14, 1986, North Texas State University, Denton, Texas. R. J. Renka, An Interpolatory Surface under Tension with Automatic Selection of Tension, SIAM Conference on Applied Geometry, July 20-24, 1987, Albany, N.Y. R. J. Renka, Scattered Data Interpolation, IMSL Seminar, March 16, 1990, IMSL, Inc., Houston, Texas (invited). R. J. Renka and A. K. Cline, Scattered Data Fitting Using a Constrained Delaunay Triangulation, Thirteenth IMACS World Congress on Computation and Applied Mathematics, July 22-26, 1991, Dublin, Ireland (invited). J. W. Neuberger and R. J. Renka, A Variable Metric Method for Solution of the Parametric Minimal Surface Problem, Fifteenth Annual Texas Partial Differential Equations Conference, March 7-8, 1992, University of North Texas, Denton, Texas. R. J. Renka and J. W. Neuberger, A Variable Metric Method for Constructing Minimal Surfaces, SMU Department of Mathematics Colloquium, December 8, 1993, Southern Methodist University, Dallas, Texas (invited). M. L. Lapidus, J. W. Neuberger, R. J. Renka, and C. A. Griffith, Snowflake Harmonics and Computer Graphics: Numerical Computation of Spectra on Fractal Drums, 103rd Annual Meeting of the AMS (Meeting #918), January 8-11, 1997, San Diego, California. J. W. Neuberger and R. J. Renka, Finding Critical Points of the Ginzburg-Landau Functional by means of Sobolev Gradients, 1997 Spring Southeastern AMS Sectional Meeting, March 21-22, 1997, Memphis, TN. J. W. Neuberger and R. J. Renka, Finding Critical Points of the Ginzburg-Landau Functional by means of Sobolev Gradients, SIAM Conference on Mathematical Aspects of Material Science, May 12-14, 1997, Philadelphia, PA. J. W. Neuberger and R. J. Renka, Approximation of Eigenvalues of the Dirichlet Laplacian on a Fractal Drum, Third IMACS Inter- national Symposium on Iterative Methods in Scientific Computation, July 9-12, 1997, Jackson Hole, Wyoming. J. W. Neuberger and R. J. Renka, Ginzburg-Landau Calculations for Superconductivity and Location of Singularities, Twenty-first Annual Texas Partial Differential Equations Conference, March 28-29, 1998, Texas A&M University, College Station, Texas. R. J. Renka and J. W. Neuberger, The Ginzburg-Landau Functional on a Rectangle with Holes, Fourth International Joint Meeting of the AMS and the Sociedad Matematica Mexicana (SMM), May 19-22, 1999, University of North Texas, Denton, Texas. J. W. Neuberger and R. J. Renka, Numerical Approximation of Critical Points of the Ginzburg-Landau Functional, Third World Congress of Nonlinear Analysts, July 19-26, 2000, Catania, Italy. J. W. Neuberger and R. J. Renka, Numerical Calculation of Critical Points of the Ginzburg-Landau Functional, AMS Annual Meeting, January 6-9, 2002, San Diego, California. R. J. Renka, A Sobolev Gradient Descent Method for Constructing Smooth Curves, Seventh SIAM Conference on Mathematical and Computational Issues in the Geosciences, March 17-20, 2003, Austin, Texas. J. W. Neuberger and R. J. Renka, Approximation of Eigenvalues of the Dirichlet Laplacian on a Fractal Drum, ICIAM 2003 -- 5th International Congress on Industrial and Applied Mathematics, July 7-11, 2003, Sydney, Australia. J. W. Neuberger and R. J. Renka, Numerical Determination of Vortices in Superconductors: Simulation of Cooling, ISEC 2003 -- International Superconducting Electronics Conference, July 7-11, 2003, Sydney, Australia. R. J. Renka, A Variable Metric Descent Method for Curve and Surface Fairing, AMS Annual Meeting, January 7-10, 2004, Phoenix, Arizona. R. J. Renka, A Sobolev Gradient Method for Construction of Elastic Curves in Regular Surfaces, Fourth World Congress of Nonlinear Analysts (WCNA-2004), June 30 through July 7, 2004, Orlando, Florida. R. J. Renka, Computational Differential Geometry and the Sobolev Gradient Method, UNT Mathematics Conference in Honor of John Neuberger's 70th Birthday, October 30-31, 2004, Denton, Texas. R. J. Renka, Constructing Fair Curves with a Gradient Descent Method, SIAM Conference on Geometric Design and Computing, October 31 through November 3, 2005, Phoenix, Arizona. R. J. Renka, Curve Fitting with a Sobolev Gradient Method, UNT Applied Mathematics Seminar, February 17, 2006, Denton, Texas. R. J. Renka, Curve Fitting with a Sobolev Gradient Method, 6th International Congress on Industrial and Applied Mathematics (ICIAM 07), July 16-20, 2007, Zurich, Switzerland. R. J. Renka, Image Segmentation with a Sobolev Gradient Method, Fifth World Congress of Nonlinear Analysts (WCNA-2008), July 2-9, 2008, Orlando, Florida. R. J. Renka, A Finite Element Method for the Steady-state Incompressible Navier-Stokes Equations, 7th International Congress of Industrial and Applied Mathematics, July 18-22, 2011, Vancouver, B.C., Canada. P. Kazemi and R. J. Renka, A Sobolev trust-region method for numerical solution of the Ginzburg-Landau equations, Variational and Topological Methods: Theory, Applications, Numerical Simulations, and Open Problems, June 6-9, 2012, Flagstaff, Arizona, USA. P. Kazemi and R. J. Renka, Convergence of the Levenberg-Marquardt method, Variational and Topological Methods: Theory, Applications, Numerical Simulations, and Open Problems, June 6-9, 2012, Flagstaff, Arizona, USA. P. Kazemi and R. J. Renka, A Levenberg-Marquardt method using Sobolev gradients, 2014 Joint Mathematics Meetings, January 15-18, 2014, Baltimore, MD, USA. R. J. Renka, A new method for finite element mesh smoothing, Texas PDE Conference 2014, March 1-2, 2014, Denton, TX, USA.

Last modified: 01/10/2017