Prof. dr. **Costică Mustăţa** – outstanding member of the Institute, at present honorary member.

He was employed at the Institute between 1968-2013, and he served as Secretary of the Scientific Council.

He is a member of the Cluj Team on Numerical Analysis and Approximation Theory.

At present, he serves as a member of the Editorial Board of *Journal of Numerical Analysis and Approximation Theory*, edited under the auspices of the Romanian Academy, and of the (ISI ranked) journal *Carpathian Journal of Mathematics. *(2008-2015?)

Version of July 16, 2017.

In Romanian:

Membru marcant al Institutului (în prezent, membru de onoare).

A fost angajat la Institut în perioada 1968-2013, unde a fost membru al Consiliului Ştiinţific.

In prezent este membru al colectivului de redactie al revistei de specialitate *Journal of Numerical Analysis and Approximation Theory*, editata sub egida Academiei Romane, precum si la *Carpathian Journal of Mathematics* (jurnal ISI).

**Personal Data**

Date and place of birth | 11 June 1942 Băileşti, district Dolj Romania |

**Education and degrees**

1975 | Ph.D. in Mathematics, University Babeş-Bolyai, Cluj-Napoca Scientific advisor: Prof. Dr. Elena Popoviciu Thesis “The best approximation of the functions with given behavior” |

1963-1968 | Batchelor Degree, Mathematics University Babeş-Bolyai, Cluj-Napoca |

1953-1956 | High school Băileşti, district Dolj |

**Employment history**

1968-1971 | Research assistant at Tiberiu Popoviciu Institute of Numerical Analysis |

1971-1979 | Researcher at Tiberiu Popoviciu Institute of Numerical Analysis |

1979-1990 | Senior researcher (III) at Tiberiu Popoviciu Institute of Numerical Analysis |

1990-1994 | Senior researcher (II) at Tiberiu Popoviciu Institute of Numerical Analysis |

1998-2004 | Associate Professor at North University of Baia-Mare |

1994-2013 | Senior researcher (I) at Tiberiu Popoviciu Institute of Numerical Analysis |

**Editorial activities**

- Member of the Editorial Board of the (ISI ranked) journal
*Carpathian Journal of Mathematics*(2008-2015?) - Member of the Editorial Board of
*Journal of Numerical Analysis and Approximation Theory*, edited at the Institute, under the auspices of the Romanian Academy (since ?) - Deputy Editor-in-Chief of the journal Mathematica, edited at the
*Babes-Bolyai University*, under the auspices of the Romanian Academy (between ?) - Member of the Editorial Board of the journal
*Creative Mathematics and Informatics*(between 2008-2015) - Member of the Editorial Board of the journal
*Southwest Journal of Pure and Applied Mathematics*Cameron University, Lawton, USA (between 1997-2004)

**Recent research domains**

- Approximation and best approximation in function spaces and abstract spaces
- Theorems of extension and relationship with problems of best approximation
- Existence and study of properties for selections associated to metric projections

**Past research activity:**

- Approximation by linear and positive operators
- Approximation of solutions of boundary problems for differential equations
- Spline functions and applications
- M-ideals in metric spaces

**Grants**

- GAR nr.4122GR/1998,1990 cu MCT, Theme: Appromaximations of the solutions for PDE by means of spline functionms and wavelets. (coordinatortor).
- GAR nr.6100GR/2000 cu ANSTI, Theme: Numerical mathods for solving boundary problems for ODE and PDE (cooordinator).
- GAR nr.65/2001 of the Romanian Academy, Theme: The unknown incremental method applied to diffusion-convection problems (coordinator)
- GAR nr.46/2002 of the Romanian Academy, Theme: The unknown incremental method applied to diffusion-convection problems (coordinator)
- GAR no.15/2003 of the Romanian Academy
- GAR no.13/2004 of the Romanian Academy

**Other professional activities**

- Scientific secretary at Tiberiu Popoviciu Institute of Numerical Analysis
- Reviewer at “Zentralblatt fur Mathematik” and “Mathematical Reviews”.
- Member in the Expert Committee of CNCSIS.

**Didactic activity**

- Linear algebra and analytical geometry
- Functional analysis
- The best approximation
- Operators theory
- Applied mathematics in economy

## Articles

- C. Mustăța,
*Sandwich theorems for radiant functions,*J. Numer. Anal. Approx. Theory, 44 (2015) no. 1, 81-90. - C. Mustăţa,
*On the extensions preserving the shape of semi-Holder function*, Results Math. 63 (2013), 425-433. - C. Mustăţa,
*On the existence and uniqueness of extensions of semi-Holder real-valued functions*, Rev. Anal. Numer. Theor. Approx., 39 (2010) no. 2, 134-140. - C. Mustăţa,
*Extensions of semi-Hölder real valued functions on a quasi-metric space*, Rev. Anal. Numer. Theor. Approx., 38 (2009), no. 2, pp. 164-169. - C. Mustăţa,
*On the approximation of the global extremum of a semi-Lipschitz function*, Mediterr. J. Math. 6 (2009), pp. 169-180. - C. Mustăţa,
*Asupra extensiei si aproximarii functiilor semi-Lipschitz reale*, Seminarul Tiberiu Popoviciu de Ecuatii Functionale, Aproximare si convexitate, 24 – 27 septembrie 2008, Cluj-Napoca, pp. 25-29. - C. Mustăţa,
*On a theorem of Baire about lower semi-continuous functions*, Rev. Anal. Numer. Theor. Approx. 37 (2008) no. 1, 71-75. - C. Mustăţa,
*Best uniform approximation of a bounded function by extensions of semi-Lipschitz functions*, Annals of the Tiberiu Popoviciu Seminar of Functional Equations Approximation and Convexity, vol. 5, 2007, 87-98. - C. Mustăţa,
*Extension and approximation of semi-Lipschitz functions*, Analele Univ. de Vest Timişoara, Seria Matematică-Informatică, 45 (2007) no. 2, 83-92. (pdf, abstr, kw, refs, ??) - C. Mustăţa,
*Best uniform approximation of semi-Lipschitz function by extension*, Rev. Anal. Numér. Théor. Approx. 36 (2007) 2, pp. 161-171. - C. Mustăţa,
*On the converses of the reduction principle in inner product spaces*, Studia Univ. Babeş-Bolyai, Mathematica, vol LI (2006) no. 3, 97-104. - S. Cobzas, C. Mustăţa,
*Best approximation in spaces with asymmetric norm*, Rev. Anal. Numer. Theor. Approx. 35 (2006) no. 1, 17-31. - C. Mustăţa,
*On the extension of semi-Lipschitz functions on asymmetric normed spaces*, Rev. Anal. Numer. Theor. Approx. 34 (2005) no.2 , 139-150. - C. Mustăţa,
*On the characterization of generalized nearest point*, Annals of the Tiberiu Popoviciu Seminar of Functional Equations, Approximation and Convexity, vol. 2 (2004), 65-74. (refs, abstr, pdf) - C. Mustăţa,
*Characterization of ε-nearest points in space with asymmetric seminorm*, Rev. Anal. Numer. Theor. Approx. 33 (2004) no. 2, 203-208. - C. Mustăţa and Şt. Cobzaş,
*Extension of bounded linear functionals and best approximation in space with asymmetric norm*, Rev. Anal. Numer. Theor. Approx.. 33 (2004) no. 1, 39-50. - C. Mustăţa,
*On the uniqueness of extension and unique best approximation in the dual of an asymmetric normed linear space*, Rev. Anal. Numer. Theor. Approx. 32 (2003) no. 2, 187-192. - C. Mustăţa,
*A Phelps type result for spaces with asymmetric norms*, Bul. Şt. Univ. Baia Mare, Seria B, Fascicola matematică-informatică, 18 (2002) no. 2, 275-280. - C. Mustăţa,
*On the extremal semi-Lipschitz function*, Rev. Anal. Numer. Theor. Approx. 31 (2002) Nr. 1, 103-108. - C. Mustăţa,
*Extension and approximation of semi-Lipschitz functions on quasi-metric linear spaces*, Proceedings of the International Symposium on Numerical Analysis and Approximation Theory 9-11 May 2002, 362-385. - C. Mustăţa,
*Extension of convex semi-Lipschitz Functions on quasi-metric linear spaces*, Seminaire de la Théorie de la Meilleure Approximation, Convexité et Optimization, Cluj-Napoca, 29 November 2001, 85-92. - C. Mustăţa,
*Extension of starshaped bounded semi-Lipschitz function on a quasi metric linear spaces*. ”135-th Pannonian Applied Mathematical Meeting” 4-7 oct. 2001, 285-291. - C. Mustăţa,
*Extension of semi Lipschitz function on quasi-metric spaces*, Rev. Anal. Numer. Theor. Approx. 30 (2001) nr. 1, 61-67. - C. Mustăţa,
*Uniqueness of extension of semi-Lipschitz functions on quasi-metric spaces*, Bul. Ştiinţ. Univ. Baia Mare, Seria B, Fascicola matematică-informatică, 16 (2000) no. 2, pp. 207-212. - C. Mustăţa,
*Some remarks concerning norm preserving extension and best approximation*, Rev. Anal. Numer. Theor. Approx., 29 (2000) No. 2, pp. 173-180. - C. Mustăţa, Şt. Cobzaş,
*Extension of Lipschitz functions and best approximation*, in ”Research on Theory of Allure, Approximation, Convexity and Optimization, SRIMA, Cluj-Napoca, (1999), 3-21. - C. Mustăţa,
*The approximation by spline functions of the solution of a polylocal problem for a differential equation of order**p*, ”Conference on Analysis, Functional Equations, Approximation and Convexity”, Cluj-Napoca, October 15-16, (1999), 197-201. - C. Mustăţa,
*On a problem of B.A. Karpilovskaya*, Rev. Anal. Numér. Théor. Approx. 29 (1999) no. 2, pp. 179-189. - A.C. Mureşan, C. Mustăţa,
*A Galerkin Methods for a singularly perturbed bilocal problem*, Bull. Şt. Univ. Baia Mare, Seria B, Fascicola Matematică-informatică, 15 (1999) nos. 1-2, 89-102. - C. Mustăţa,
*On the derivative-interpolating spline functions of even degree*, Bull. Şt. Univ. Baia Mare, Seria B, Fascicola Matematică-informatică, 14 (1998) no. 1, 51-58. - C. Mustăţa, Şt. Cobzaş,
*Extension of bilinear functionals and best approximation in 2-normed space*, Studia Univ. ”Babeş-Bolyai”, Seria Mathematica, XLIII, Nr.2 (1998), 1-13. - C. Mustăţa, A. Mureşan and R. Mustăţa,
*The approximation by spline functions of the solutions of a singularly perturbed bilocal problem*, Rev. Anal. Numér. Théor. Approx. 27 (1998). - C. Mustăţa,
*Approximation by spline functions of the solutions of a linear bilocal problem*, Rev. Anal. Numér. Théor. Approx. 26 (1997) 1-2. 137-148. - C. Mustăţa, Şt. Cobzaş,
*Extension of bilinear operators and best approximation in 2-normed spaces*, Rev. Anal. Numér. Théor. Approx., 25 (1996) nos. 1-2, 63-75. - C. Mustăţa,
*On the metric projection and the quotient mapping*, Rev. Anal. Numér. Théor. Approx., 24 (1995) nos. 1-2, 191-199. - C. Mustăţa, Şt. Cobzaş,
*Selections associated to the metric projection*, Rev. Anal. Numér. Théor. Approx., 24 (1995) nos. 1-2, 45-52. - C. Mustăţa,
*On the selections associated to the metric projection*, Rev. Anal. Numér. Théor. Approx. 23 (1994) 1, 89-93 (MR # 96b: 46019). - C. Mustăţa,
*Common selections for the metric projections*, Mathematica 35 (58) (1993) 2, 193-200. - C. Mustăţa,
*Selections with values Bernstein polynomials associated to the extension operator for Lipschitz functions*, Rev. Anal. Numér. Théor. Approx. 22 (1993) 2, 207-216. - C. Mustăţa,
*Selections associated to McShane’s extension theorem for Lipschitz functions*, Rev. Anal. Numér. Théor. Approx. 21 (1992) 2, 135-145. - C. Mustăţa,
*On a problem of extremum*, ”Babeş-Bolyai” Univ., Research Seminars, Seminar on Mathematical Analysis, Preprint nr.7 (1991), 87-93. - C. Mustăţa,
*Extension of Hölder functions and some related problems of best approximation*, ”Babeş-Bolyai” Univ., Research Seminars, Seminar on Mathematical Analysis, Preprint nr. 7 (1991), 71-86. - C. Mustăţa,
*An application of a theorem of McShane*, Seminar on Functional Analysis and Numerical Methods, Preprint Nr. 1 (1989), 75-84. - C. Mustăţa, D. Andrica,
*An abstract Korovkin type theorem and applications*, Studia Univ. ”Babeş-Bolyai” XXXIV, fasc. 2 (1989), 44-41. - C. Mustăţa,
*M-ideals in metric spaces*, ”Babeş-Bolyai” University, Faculty of Math. and Physics, Research Seminars, Seminar on Mathematica Analysis, Preprint Nr.7 (1988), 67-74. - C. Mustăţa, C. Iancu,
*Error estimation in the approximation of function by interpolation cubic splines*, Mathematica 29 (52) 1 (1987), 33-39. - C. Mustăţa,
*On the exactity of the error evaluation in the approximation by cubic spline of interpolation*, ”Babeş-Bolyai” University, Faculty of Math. and Physics, Research Seminars, Seminar on Functional Analysis and Numerical Methods, Preprint no. 1 (1987), 93-102. - C. Mustăţa,
*On the uniqueness of extension of Lipschitz odd functions*, ”Babeş-Bolyai” University, Seminar on Optimization Theory, Report no. 8 (1987), 75-80. - C. Mustăţa,
*On the extension of Lipschitz functions*, Seminar of Funct. Analysis and Numerical Methods, Preprint Nr. 1 (1986), 83-92. - C. Mustăţa,
*On the extension of Hölder functions*, Seminar of Functional Analysis and Numerical Methods, Preprint Nr. 1 (1985), 85-92. - C. Mustăţa,
*On a surjectivity theorem*, Seminar of Functional Analysis and Numerical Methods, Preprint Nr. 1, (1985), 73-84. - C. Mustăţa,
*About the determination of extremes of Hölder functions*, Seminar of Functional Analysis and Numerical Methods, Preprint Nr. 1 (1983), 107-116. - C. Mustăţa,
*On the extension problem with prescribed norm*, Seminar Funct. Anal. and Num. Methods, Preprint Nr. 4 (1981), 93-99. - C. Mustăţa,
*Extension of bounded Lipschitz functions and some related problems of best approximation*, Seminar of Functional Analysis and Numerical Methods, Preprint Nr. 1 (1980), 1-22. - C. Mustăţa,
*On the uniqueness of the extension of real Hölder functions*, Sem. Itinerant de Ecuaţii Funcţionale, Aproximare şi Convexitate, 1980, Cluj-Napoca, 91-96 (in Romanian). - C. Mustăţa,
*The extension of starshaped bounded Lipschitz functions*, Anal. Numer. Théor. Approx. 9 (1980) 1, 93-99. - C. Mustăţa, Şt. Cobzaş,
*Norm preserving extension of convex Lipschitz functions*, J. Approx. Theory 24 (1978) no. 3, 238-244. - C. Mustăţa,
*A characterization of semi-chebyshevian sets in a metric space*, Anal. Numér. Théor. Approx., 7 (1978) 2, 169-170. - C. Mustăţa,
*Best approximation and unique extension of Lipschitz functions*, J. Approx. Theory 19 (1977) no. 3, 222-230. - C. Mustăţa,
*Norm preserving extension of starshaped Lipschitz functions*, Mathematica 19 (42) 2 (1977), 183-187. - C. Mustăţa,
*A characterization of Chebyshevian subspaces of \(Y^\perp\)-type*, Anal. Numér. Théor. Approx., 6 (1977) 1, 51-56. - C. Mustăţa,
*On the best approximation in metric spaces*, Anal. Numér. Théor. Approx., 4 (1975) 1, 45-50. - C. Mustăţa,
*A monotony property of the best approximation operator in the space of Lipschitz functions*, Rev. Anal. Numer. Teoria Approximatiei 3 (1974) 2, 153-160 (in Romanian). - C. Mustăţa,
*A classification of Lipschitz functions*, Rev. Anal. Numer. Teoria Approximatiei 3 (1974) 1, 107-111 (in Romanian). - C. Mustăţa, Gh. Lupu,
*Consideration on the ”equilibrium” electrons distribution function for a homogeneous high frequency, fully ionized plasma*, Rev. Roumaine de Physique 18 (1973) 3, 365-372. - C. Mustăţa,
*On the uniqueness of the extension of continuous p-seminorms*, Rev. Anal. Numer. Teoria Approximatiei 2 (1973) no. 2, 173-177 (in Romanian). - C. Mustăţa,
*On the Chebyshev subspaces in normed space of Lipschitz functions*, Rev. Anal. Numer. Teoria Approximatiei, 2 (1973) no. 1, 81-87 (in Romanian).

PhD Thesis

*The best approximation of the functions with given behavior*, Scientific advisor Prof. Dr. Elena Popoviciu, University Babeş-Bolyai, Cluj-Napoca, 1975.

Other works

Other works