Table of contents : Title......Page 1 Copyright ......Page 2 PREFACE ......Page 3 PARTICIPANTS ......Page 4 BOOLEAN METHODS IN FOURIER APPROXIMATION ......Page 7 ILL-POSED PROBLEMS IN MULTIVARIATE APPROXIMATION by E.W. Cheney ......Page 19 ON MULTIVARIATE VERTEX SPLINES AND APPLICATIONS by Charles K. Chui and Mingjun Lai ......Page 25 ON THE THEORY AND APPLICATION OF EXPONENTIAL SPLINES by W.Dahmen and C.A. Micchelli ......Page 43 INTERPOLATION OF SCATTERED DATA BY RADIAL FUNCTIONS by N.Dyn ......Page 53 SHAPE PRESERVING SURFACE INTERPOLATION by F.Fontanella ......Page 69 RECENT ADVANCES IN THE APPROXIMATION OF SURFACES FROM SCATTERED DATA by R.Franke ......Page 85 METAHARMONIC SPLINES FOR SOLVING THE EXTERIOR DIRICHLET PROBLEM FOR THE HELMHOLTZ EQUATION by W.Freeden ......Page 105 APPROXIMATION BY HARMONIC FUNCTIONS by Werner Haussmann ......Page 117 A SHORT SURVEY ON CARDINAL INTERPOLATION BY BOX SPLINES by K. Jetter......Page 131 UNISOLVENT INTERPOLATION IN ]Rn AND THE SIMPLICIAL POLYNOMIAL FINITE ELEMENT METHOD by A.J.Y. Le Mehaute ......Page 147 ON INTERPOLATION SYSTEMS AND ?-REDUCIBLE INTERPOLATION PROBLEMS by J. Lorente and V. Ramirez ......Page 159 ATTENUATION FACTORS AND MULTIVARIATE PERIODIC SPLINE INTERPOLATION by H.G. ter Morsche ......Page 171 COORDINATE FREE SCATTERED DATA INTERPOLATION by G.M. Nielson ......Page 181 APPROXIMATION BY POSITIVE ELEMENTS OF SUBALGEBRAS OF REAL-VALUED FUNCTIONS by J.B. Prolla......Page 191 NUMERICAL GENERATION OF NESTED SERIES OF GENERAL TRIANGULAR GRIDS by M.-C.Rivara ......Page 199 COMPOSITE FINITE ELEMENTS OF CLASS C2 by P.Sablonniere ......Page 213 TRIANGULATION METHODS by L.L. Schumaker ......Page 225 CONSTRAINED SURFACE CONSTRUCTION by F.I.Utreras ......Page 239 CONSTRAINED SURFACE CONSTRUCTION by F.I.Utreras ......Page 239 POLYNOMIAL REPRODUCING FORMULAS AND THE COMMUTATOR OF A LOCALLY SUPPORTED SPLINE by J.D.Ward ......Page 261 ON INEQUALITIES ARISING FROM BEST LOCAL APPROXIMATIONS IN RECTANGLES by F.Zo......Page 271 A BIBLIOGRAPHY OF MULTIVARIATE APPROXIMATION by R.Franke and L.L. Schumaker ......Page 281