Tiberiu Popoviciu Institute of Numerical Analysis

Since 1951

Founded in 1951 by T. Popoviciu

Research fields

Numerical Analysis & Modeling

Most notable

invent. B-splines (nonunif. grids)

The institute has organized during 3-6 November 2025 the international conference Numerical Analysis, Numerical Modeling, Approximation Theory (NA-NM-AT 2025) as part of the 2025 edition of the Cluj Academic Days.

The conversion of the LaTeX files into HTML (with their posting on the website) has been started for the scientific papers published in the last 10 years (see, e.g., paper1, paper2, paper3, paper4, paper5, paper6, etc.).

This operation is required in order to improve the interaction of our website with the search engine, as this standard is de facto for certain publishing houses (e.g., Springer, Elsevier, etc.).

This process has been finalized for the papers published since 2010 in the journal edited at ICTP, J. Numer. Anal. Approx. Theory.

The institute has started recovering and posting its Annual Reports, since its foundation, in 1951.

The list of papers are completed for the years 1951-1956, 1957-1975 (in progress), 1976-1989 (March 7, 2024), while the full activity reports of 1990-present were already posted for some years.

Here we see the first page of the Annual Report of 1957, when the Institute started to build electronic computers (see the history page).

One of the most viewed pages87%
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Institute history (please use your browser translator).

In 2022 Journal of Numerical Analysis and Approximation Theory – edited by the Institute – has celebrated 50 years.

Dr. Emil Cătinaș, Editor-in-Chief, has given the talk “The 50th anniversary of the Journal of Numerical Analysis and Approximation Theory“, at the opening ceremony of the Cluj Academic Days 2022 (October 7).

On October 12, 2023, the editorial board is organizing a workshop with the members of the Editorial Board and with the members of ICTP who are supporting the JNAAT activities in order to discuss further management strategies.

In 2021 the Institute has celebrated 70 years from its foundation.

The symposium 70 years from the foundation of the „Tiberiu Popoviciu” Institute of Numerical Analysis was organized on October 28, 2021, in the frame of Academic Days of Cluj-Napoca 2021.

Notable results

  • Papers (in journals: SIAM Rev., Numer. Math., Math. Comp., Found. Comput. Math., J. Comp. Phys., Adv. Water Res.,…)
  • Books (in: Springer, Birkhauser,…)
  • Survey, JCR/ISI,… papers
  • Honors,…

Works, categorized -as posts- by

Birkhäuser/Springer

Springer

Springer

Lambert

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Supercomputing experience

Cooperation agreements with Forschungszentrum Jülich (Germany), allowing numerical applications on supercomputers.

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Journal of Numerical Analysis and Approximation Theory

A peer-reviewed journal since 1972 (last year, in 2022, it has celebrated its semicentennial). Covered by Scopus since 2022.

cover JNAAT
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acad. Tiberiu Popoviciu

 

One of the greatest Romanian mathematicians.

One of the Romanian computer pioneers.

Appears in the select History of Approximation Theory.

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Some of the first electronic computers in Romania built here:

  • MARICA, ’59, relay computer;
  • DACICC-1, ’63, 3rd in Romania, but 1st with transistors & RAM memory;
  • DACICC-200, ’68, most powerful Romanian computer; 1st with OS & compiler.
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The tree of the PhD descendants of T. PopoviciuG. Călugăreanu and D.V. Ionescu.

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LinkedIn
YouTube

Seminar Talks

Announcements

Rareș Răhăian: The elliptic Cauchy problem with applications in Electrocardiographic Imaging (ECGi) (Seminar Talk)

Announcements
On Wednesday 20th of May 2026 starting at 10am, Rareș Răhăian will give a talk at the Institute Seminar. Title: The elliptic Cauchy problem with applications in Electrocardiographic Imaging (ECGi) Abstract: This talk…

Radu Precup: Triad: modelling – theory – computation in control (Seminar Talk)

Announcements
On Wednesday 6th of May 2026 starting at 10am, Radu Precup will give a talk at the Institute Seminar. Title: Triad: modelling – theory – computation in control Abstract: We consider the general…

Octavian Agratini: Asymptotic expansion for Post-Widder operators (Seminar Talk)

Announcements
On Wednesday 29th of April 2026 starting at 10am, Octavian Agratini will give a talk at the Institute Seminar. Title: Asymptotic expansion for Post-Widder operators Abstract: We present a study of the asymptotic…

Publications

Convex functions

Books, convexity, divided differences, html, Mathematical Analysis, not-at-ICTP, Numerical Analysis, PDF, works
Abstract AuthorsTiberiu Popoviciu Tiberiu Popoviciu Keywordsconvex functions of higher order. Paper coordinatesT. Popoviciu, Les fonctions convexes, Hermann, Paris, 1944 (in French). PDF1944-a -182 -Popoviciu- Actualites scientifiques et industrielles 992 – Les…

On best approximation of the continous functions by polynomials

approximation of multivariate functions, approximation of univariate functions, Approximation Theory, best approximation, Books, html, Modulus of continuity, modulus of smoothness, not-at-ICTP, Numerical Analysis, remainder estimation, works
Abstract AuthorsTiberiu Popoviciu Tiberiu Popoviciu Keywords? Paper coordinatesT. Popoviciu, On the best approximation of continuous functions by polynomials, Cluj, Editura Ardealul, 1937. PDF1937 a -135- Popoviciu- Monografii Matematice – Despre…

Solving polynomial operator equations of degree 2 by Steffensen-type iterations with approximate inverses

(proceedings), Convergence order, eigenvalue/eigenvector problems, html, nonlinear systems in Rn, Numerical Analysis, numerical linear algebra, paper, PDF, Schulz type iterations, solving F(x)=0 iteratively, Steffenssen methods, works
Abstract AuthorsI. Păvăloiu (Tiberiu Popoviciu Institute of Numerical Analysis) Ion Păvăloiu Emil Cătinaş (Tiberiu Popoviciu Institute of Numerical Analysis) Emil Cătinaş Keywords? Paper coordinatesE. Cătinaş, I. Păvăloiu, Solving polynomial operator…

Some aspects of the problem of accuracy in numerical computations

(original), accuracy/perturbations, Numerical Analysis, paper
Abstract ? AuthorsTiberiu Popoviciu (Institutul de Calcul) Original title (in French)Certains aspects du problème de la précision dans les calcules numériques Keywords? Cite this paper asT. Popoviciu, Certains aspects du problème…

On some formulas for numerical differentiation

(original), Numerical Analysis, numerical derivative, paper, PDF, works
Abstract AuthorsD.V. Ionescu (Institutul de Calcul) Dumitru V. Ionescu (1901-1985) Keywords? Paper coordinatesD.V. Ionescu, Sur quelques formules de dérivation numérique. (French) Bull. Math. Soc. Sci. Math. R. S. Roumanie (N.S.) 12 (60) 1968 no. 2,…