- Polynomial Approximation Theory
- Positive Operators
- Weighted polynomial inequalities
- Polynomial Interpolation Processes
- Rational Approximation
- Fourier Series
- Orthogonal Polynomials
- Quadrature Rules
- Integral Equations

- Member of the Organizing Committee of the VII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII Summer School of Computational Mathematics for young researchers;
- Member of the Organizing Committee of the ``First, Second, Third, Fourth, Fifth and Sixth Conference in Functional Analysis and Approximation Theory", which took place in Maratea (Potenza, Italy) in the month of September of 1989, 1992, 1996, 2000, in the month of June of 2004 and in the month of September 2009, respectively;
- Member of the Scientific Committee of the ``Third International Symposium on Orthogonal Polynomials and their Applications", Erice (Italy), June 1-8, 1990;
- Member of the Scientific Committee of the ``ICAOR '96", Cluj--Napoca (Romania) July 29-August 3, 1996;
- Member of the Scientific Committee of the ``Workshop on Advanced special functions and applications", Melfi (Potenza, Italy) May 9-11 1999;
- Member of the Organizing Committee of the "Workshop on Quadrature and Numerical Methods for Integral Equations", Rifreddo (Potenza, Italy), September 16-20, 2000;
- Member of the Scientific Committee of the Conference "Approximation & Computation 2008. Conference dedicated to Prof. Gradimir V. Milovanovic on the occasion of his 60-th anniversary", Nis (Serbia), August 25-29, 2008
- Member of the Organizing Committee of the Conference "Recent Developments in Functional Analysis and Approximation Theory. Celebrating Francesco Altomare's 60th birthday", Lecce, September 22--24, 2011.

- "Polinomi ortogonali e loro applicazioni", ex 60% of the Italian Ministry of the University and Research, leader G. Mastroianni (1996)
- "Analisi Numerica e Matematica Computazionale", ex 40% of the Italian Ministry of the University and Research, leader F. Fontanella (1996-97)
- "Approximation Theory and its Applications", Hungarian--Italian intergovernmental S&T cooperation program (1996--97)
- "Polinomi ortogonali e risoluzione numerica di equazioni integrali", bilateral project with University of Chemnitz (Germany) (Programma Vigoni, Prot.301/96/P/rg) (1996--98)
- "Metodi degli elementi al contorno per la risoluzione numerica di problemi di meccanica della frattura", C.N.R. (National Research Center) project, leader G. Monegato (1996--98)
- "Analisi Numerica: Metodi e Software Matematico", National Project, leader V. Ruggiero (1997--1999)
- "Opportuni operatori di interpolazione per metodi numerici per l'elaborazione di segnali", bilateral project with Institute GSF of Munich (Germany) (Programma Vigoni, Prot.1/98/P/rg) (1998-99)
- "Trattamento numerico di equazioni integrali e connessi problemi di quadratura ed algebra lineare", ex 60% of the Italian Ministry of the University and Research, leader G. Mastroianni (1999);
- "Teoria costruttiva delle funzioni e problemi connessi", GNIM project, leader M. Bozzini (1999-2000)
- "Approssimazione e quadratura numerica in una o più dimensioni", GNIM project, leader G. Mastroianni (2000--01)
- "Trattamento numerico di equazioni integrali e di connessi problemi di algebra lineare", GNCS project, leader G. Rodriguez (2001--02)
- "Metodi numerici per equazioni integrali", GNCS project, leader G. Mastroianni (2003)
- "Trattamento numerico di equazioni integrali singolari e connessi problemi di approssimazione e quadratura", GNCS project, leader G. Mastroianni (2004)
- "Trattamento numerico di equazioni integrali singolari e connessi problemi di approssimazione e algebra lineare", GNCS project, leader G. Mastroianni (2005)
- "Metodi numerici per l'algebra lineare strutturata e applicazioni", PRIN project, leader D. Bini (2007--08)
- "Tecniche numeriche per problemi di propagazione di onde elastiche in multidomini", GNCS project, leader A. Aimi (2011)
- "Accoppiamento di metodi numerici per BIEs e PDEs relative a problemi evolutivi esterni e multistrato", GNCS project, leader A. Aimi (2012)

- Annales Mathematicae et Informaticae (Eger, Hungary)
- Facta Universitatis, Series Mathematics and Informatics (Nis, Serbia)
- Studia Mathematica of the Babes-Bolyai University (Cluj-Napoca, Romania)

- Acta Matematica Hungarica
- Applied Numerical Mathematics
- Bullettin of the Malaysian Mathematical Sciences Society
- Calcolo
- Computers and Mathematics with applications
- Contructive Approximation
- Electronic Transaction of Numerical Analysis
- Jaén Journal on Approximations
- Journal of Applied Mathematics and Computing
- Journal of Approximation Theory
- Journal of Computational and Applied Mathematics
- Journal of Inequalities and Applications
- Journal of Integral Equations and Applications
- Journal of Zhejiang University Sciences
- Mathematics of Computation
- Numerische Mathematik
- Numerical Algorithm
- SIAM Journal of Numerical Analysis
- Soochow Journal of Mathematics
- Studia Scientiarum Mathematicarum Hungarica

- "Erdos Visiting Professorship" at the Alfred Renyi Institute of Mathematics of the Hungarian Academy of Sciences, Budapest, Hungary, in the period June 17 - July 4, 1999;
- Department of Mathematics, University of Witwaterstrand, Johannesburg, South Africa, in the period October 13 - 30, 1999;
- Alfred Renyi Institute of Mathematics of the Hungarian Academy of Sciences, Budapest, Hungary, in the period May 26 - June 30, 2002;
- Bolyai Institute Szeged, Hungary;
- Department of Mathematics, Faculty of Electronic Engineering, Nis, Serbia;
- Department of Mathematics of the Technische Universität Chemnitz, Chemnitz, Germany, in the period May 17-22, 2010 (ERASMUS);
- Alfred Renyi Institute of Mathematics of the Hungarian Academy of Sciences, Budapest, Hungary, in the period August 19 - 29, 2010;
- University of Megatrend of Belgrade, Serbia, in the period September 18-22, 2010;
- Department of Mathematics of the Technische Universität Chemnitz, Chemnitz, Germany, in the period October 4-8, 2010 (Summer School on Applied Analysis).
- Department of Mathematics of the Technische Universität Chemnitz, Chemnitz, Germany, in the period May 22-28, 2011 (ERASMUS);
- Department of Mathematics of the Technische Universität Chemnitz, Chemnitz, Germany, in the period June 17-23, 2012 (ERASMUS);

- Department of Mathematics, Faculty of Engineering, University of Pisa, Italy;
- Department of Mathematics, Faculty of Engineering, University of Rome "La Sapienza", Italy;
- Department of Mathematics, Politecnico of Milan, Italy;
- Department of Mathematics, University of Pavia, Italy;
- Department of Mathematics, University of Pisa, Italy;
- Department of Mathematics, University of Turin, Italy;
- Department of Mathematics, Politecnico of Turin, Italy;
- Department of Mathematics, University of Modena, Italy;
- Department of Mathematics, University of L'Aquila, Italy;
- Department of Mathematics, ``G.Castelnuovo", University of Rome ``La Sapienza", Italy;
- Department of Mathematics, University of Cosenza, Italy;
- Department of Mathematics, University of Messina, Italy;
- Accademia Peloritana dei Pericolanti, Messina, Italy;
- Alfred Renyi Institute of Mathematics, Hungarian Academy of Sciences, Budapest, Hungary;
- Institute of Mathematics A. Bolyai, University of Szeged, Hungary;
- Academy of Sciences, Berlin, Germany;
- Istituto per Applicazioni della Matematica, CNR, Naples, Italy;
- Banach Center, Varsavia, Poland;
- Department of Mathematics, Faculty of Electronic Engineering, University of Nis, Serbia;
- Department of Computer Science, Purdue University, Lafayette (Indiana), USA;
- Department of Mathematics, University of South Florida, Tampa (Florida), USA;
- Department of Mathematics, Ohio State University, Columbus (Ohio), USA;
- Institut für Mathematik, Universität Hildesheim, Hildesheim, Germany;
- Facultät für Mathematik, Technische Universität Chemnitz--Zwickau, Chemnitz, Germany;
- Institut für Biomathematik und Biometrie, GSF, Munich, Germany;
- Department of Mathematics, University of Witwaterstrand, Johannesburg, South Africa;
- Department of Mathematics, Stellenbosch University, South Africa.
- Department of Mathematics, Faculty of Engineering, University of Cagliari, Italy;
- Department of Mathematics, University of Lecce, Italy;
- Department of Mathematics, Seconda Università di Napoli, Italy;
- Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Puebla, Mexico;
- School of Mathematics, Georgia Institute of Technology, Atlanta, USA;
- University of Megatrend of Belgrade, Serbia;
- Serbian Academy of Sciences, Belgrade, Serbia.

- International Conference on Constructive Theory of Functions, Varna, Bulgaria, May 1987;
- ICIAM Conference, Paris, France, June 1987;
- UMI Conference, Turin, Italy, 1987;
- Third Conference on Numerical Methods and Approximation Theory, Nis, Serbia, August 1987;
- XII IMACS WORLD Congress, Paris, France, July 1988;
- Conference on Numerical Analysis, Rome, Italy, 1988;
- College Station, Texas, USA, January 1989;
- NATO School on Orthogonal Polynomials, Columbus, Ohio-State, USA, 1989;
- Conference on Special Function, Winnipeg, Manitoba, USA, 1989;
- First Trend in Functional Analysis and Approximation Theory, Maratea (Potenza), Italy, 1989;
- First USA--URSS Conference on Approximation Theory, Tampa, Florida, USA, June 18--24 1990;
- Third Conference on Orthogonal Polynomials and their Applications, Erice, Italia, June 1--8, 1990;
- Conference on Approximation Theory, Kecskemet, Hungary, August 5--11, 1990;
- NATO--ASI Conference on Approximation Theory, Spline Functions and Applications, Maratea (Potenza), Italy, April 28--May 3, 1990;
- International Conference on Constructive Theory of Functions, Varna, Bulgaria, May 28--June 1, 1991;
- XIV UMI Conference, Catania, Italy, September 19--25, 1991;
- Fifth International Congress on Computational on Applied Mathematics, Leuven, Belgium, July 27--August 1, 1992;
- Second International Conference in Functional Analysis and Approximation Theory, Maratea (Potenza), Italy, September 14--19, 1992;
- International Symposium on Operator Equation and Numerical Analysis, Gosen, Berlin, Germany, September 28--October 2, 1992;
- Numerische Integration, Oberwolfach, Germany, November 8--14, 1992;
- Conference on Approximation Theory, Budapest, Hungary, April 1993;
- Coference in honour of the 70th birthday of Prof. L. Gatteschi, Turin, Italy, October 1993;
- Conference in honour of prof. W. Gautschi, Lafayette, USA, December 1993;
- Integral and Pseudo--Differential Equation, Oberwolfach, Germany, January 1994;
- Special semester in Approximation Theory, Tel Aviv, Israel, May 1994;
- Recent Developments in Approximation Theory, Wavelets and Applications, Maratea (Potenza), Italy, May 1994;
- VI International Congress on Computational on Applied Mathematics, Leuven, Belgium, July 26--August 1, 1992;
- Orthogonality, Moment Problems and Continued Fractions, Delft, Holland, November 1994;
- IDOMAT Approximation Theory, Dortmund, Germany, March 1995;
- International Conference on Approximation Theory and Function Series, Budapest, Hungary, August 1995;
- Workshop on Approximation Theory and Results in Numerical Study of Differential and Integral Equations, Cortona, Italy, October 1995;
- Mitrinovic International Conference, Nis, Serbia, June 19--23, 1996;
- Third International Conference on Functional Analysis and Approximation Theory, Acquafredda di Maratea (Potenza), Italia, September 23-28, 1996;
- ICAOR '96, Cluj--Napoca, Romania, July 29--August 3, 1996;
- International workshop on Approximation Theory and Numerical Analysis, Dedicated to Professor M.R. Occorsio for his 65th birthday, Vico Equense (Napoli), Italy, September 9-11, 1997;
- VIII Simposium sobre polinomios ortogonales y applicaciones, Siviglia, Spain, September 22--26, 1997;
- IDOMAT '98, Dortmund, Germany, February 23--27, 1998;
- Applications and computation of orthogonal polynomials, Oberwolfach, Germany, March 23--28, 1998;
- ICCAM '98, Leuven, Belgium, July 27--August 1, 1998;
- "When does the Lagrange polynomial behave like the best approximation?", Approximation Theory, Workshop in occasion of the 60th birthday of J. Szabados, Budapest, Hungary, August 21--23, 1998;
- Applied Sciences and Mathematics, Workshop in occasion of the 65th birthday of R. Dordevic, Nis, Serbia, August 28--29, 1998;
- "Integral Equations in some Weighted Besov Spaces", Recent advances in analytical and numerical treatment of operator equations, Conference in memory of S. Prössdorf, Chemnitz, Germany, March 25--29, 1999;
- Workshop on Advanced special functions and applications, Melfi (Potenza), Italy, May 9--11, 1999;
- "Weighted Lagrange Interpolation", Paul Erdös and his mathematics, Conference in memory of Paul Erdös, Budapest, Hungary, July 4--11, 1999;
- "Weighted Lagrange Intepolation in some Sobolev Spaces", Functions, Series, Operators, Alexits Memorial Conference, Budapest, Hungary, August 9--14, 1999;
- "Polynomial Approximation on the real semiaxis", Third Workshop on Orthogonal Polynomials, Approximation and Harmonic Analysis, Inzell, Germany, April 14--18, 2000;
- "Polynomial Approximation of functions with singularities", Workshop on Analysis (to celebrate the 50th anniversary of the Mathematical Institute of the Hungarian Academy of Science of Budapest) Budapest, Hungary, June 1--3, 2000;
- Workshop on Advanced Special Functions and Integration Methods, Melfi (Potenza), Italy, June 18--23, 2000;
- ICCAM 2000, Leuven, Belgium, July 17-21, 2000;
- Workshop on Quadrature and Numerical Methods for Integral Equations, Rifreddo (Potenza), Italy, September 16-20, 2000;
- Fourth International Conference on Functional Analysis and Approximation Theory, Acquafredda di Maratea (Potenza), Italy, September 22-28, 2000;
- Toeplitz Matrices, Conference to celebrate B. Silbermann's 60th birtday, Pobershau, Germany, April 8--11, 2001;
- Conference in Analysis, Conference in honour of P. Vertesi, Budapest, Hungary, July 23--28, 2001;
- "Polynomial Approximation", Functional Spaces and Integral Equations, Workshop on Numerical Methods for Evolutionary Problems, Peschici, Italy, September 17--20, 2001;
- Filomath, Nis, Serbia, August 2001;
- "Numerical Integration and its Complexity", Numerical Integration and its Complexity, Oberwolfach, Germany, November 18--24, 2001;
- "Lagrange interpolation of functions having inner singularities", Contructive Approximation, Conference in honour of the 70th birthday of B. Sendov, Varna, Bulgaria, June 17-23, 2002;
- ICCAM 2002, Leuven, Belgium, July 22--26, 2002;
- "Metodi numerici per equazioni integrali di Fredholm di II tipo su intervalli limitati e illimitati", Equazioni integrali e problemi connessi di algebra lineare, Cagliari, Italy, September 10-11, 2002;
- Analisi Numerica: stato dell'arte, Arcavacata di Rende, Cosenza, Italy, September 26-28, 2002;
- "Fourier sum and Lagrange interpolation at Laguerre zeros", Semester in honour of Geza Freud, Budapest, Hungary, February 27, 2003;
- "Polynomial approximation on the semiaxis with Laguerre weights", IV International Meeting on Approximation, Ubeda, Spain, June 14-17, 2003;
- "Weighted approxiamtion on [0,\infty) and Fredholm equations", Fourteenth International Workshop on Operator Theory and Applications, Cagliari, Italy, June 24-27, 2003;
- Conference on Orthogonal Functions and Related topics, in honor of Professor Olav Njastad, Roros, Norway, August 12-16, 2003;
- "Christoffel functions and some applications", Giornate di Studio dedicate a Luigi Gatteschi, Università di Roma Tre, Roma, Italy, September 12-13, 2003;
- "Numerical Methods for Fredholm integral equations of the second kind", Workshop on Applied Orthogonal Systems, Constructive Approximation and Numerical Methods in honor of Professor Gradimir Milovanovic, Kragujevac, Serbia, October 10,2003;
- "Numerical Treatment of Fredholm integral equations and condition number", Convegno GNCS 2004, Montecatini Terme, Italy, February 9-11, 2004;
- "Some numerical methods for the second kind F.I.E. on the real semiaxis", International Workshop on the Technological Aspects of Mathematics (IWTAM II), in honor of Prof. Donato Trigiante for his 60-th birthday, Montecatini Terme, Italy, April 1-3, 2004;
- "Mapping properties of some singular operators", V International Meeting on Approximation, Ubeda, Spain, June 9-14, 2004;
- Fifth International Conference on Functional Analysis and Approximation Theory, Acquafredda di Maratea (Potenza), Italy, June 16-23, 2004;
- "Polinomial approximation on unbounded intervals", Fejer - Riesz Conference, Eger, Hungary, 9-13 giugno 2005;
- "Weighted polynomial approximation on [0,+\infty): polymomial inequalities, best approximation and embedding theorems", Conference on Numerical Analysis and Approximation Theory (NAAT 2006), Cluj-Napoca, Romania, July 5-8, 2006;
- "Numerical Treatment of some classes of Fredholm integral equations", Sixth International Conference on Numerical Methods and Applications, Borovets, Bulgaria, August 20-24, 2006;
- "Polynomial Approximation on the real semiaxis", VII International Meeting on Approximation Theory, Ubeda, Spain, August 31- September 3, 2006;
- "Approssimazione Globale e trattamento numerico di equazioni integrali", Equazioni integrarli: recenti sviluppi numerici e nuove applicazioni, Parma, Italy, September 27-28, 2007;
- "Approximation of function with doubling weights", VIII International Meeting on Approximation Theory, Ubeda, Spain, November 7-11, 2007;
- "Some Results in Weighted Polynomial Approximation", Conference on Approximation Theory Dedicated to the 70th Birthday of Jozsef Szabados, Budapest, Hungary, July 6-12, 2008;
- "Nyström method for Fredholm integral equations on the real semiaxis", Approximation & Computation, Conference dedicated to Prof. Gradimir V. Milovanovic on the occasion of his 60-th anniversary, Nis, Serbia, August 25-29, 2008;
- "Some results on Fourier sums in orthonormal systems", Sorok, függvények, véletlen változók, operátorok, Conference dedicated to the 70-th birthday of Professor Ferenc Móricz, Szeged, Hungary, May 29-30, 2009;
- "Polynomial approximation with exponential weights on [-1,1]", X International Meeting on Approximation Theory, Ubeda, Spain, June 27-July 2, 2009;
- "Revisiting a Quadrature Method", Workshop on Advances and Trends in Integral Equations. Dedicated to the memory of Siegfried Prössdorf, Chemnitz, Germany, October 5-9, 2009;
- "A Quadrature Method for CSIE", Workshop on Integral Equations: recent numerical developments and new applications, Parma, Italy, October 29-30, 2009.
- "Polynomial approximation with exponential weights", I Jaen Conference on Approximation, Ubeda, Spain, July 4--9, 2010.
- "Numerical treatment of Fredholm integral equations: some remarks and applications", Second International Conference on Numerical Analysis and Approximation Theory, Cluj-Napoca, Romany, September 23--26, 2010.
- "Lagrange Interpolation based on Pollaczek-type zeros", Workshop on Functional Analysis and Operator Theory, dedicated to Bernd Silbermann on his 70th birthday, Altenberg, Germany, March 29 - April 1, 2011.
- "Polynomial approximation with exponential weights on the real semiaxis", II Jaen Conference on Approximation Theory, Ubeda, Spain, June 26 - July 1, 2011.
- "Lagrange interpolation with exponential weights on the real semiaxis", Paul Turan Memorial Conference, Budapest, Hunghery, August 22-26, 2011.
- "Lagrange interpolation with exponential weights on [-1,1]", Peter Vertesi's 70--Workshop, Budapest, Hunghery, August 27, 2011.
- "Algebraic Fourier Sums. A short survey", Recent Developments in Functional Analysis and Approximation Theory, Lecce, September 22--24, 2011.
- "Weighted polynomial approximation", International Conference on Scientific Computing, S. Margherita di Pula, Sardinia, Italy, October 10-14, 2011.
- "Gaussian rules w.r.t. exponential weights in finite or infinite intervals", Congresso Nazionale SIMAI, Turin, Italy, June 25-28 , 2012.
- "Remarks on L^p convergence of Hermite interpolation", III Jaen Conference on Approximation Theory, Ubeda, Spain, July 15-20, 2012.
- "Weighted interpolation for functions defined on the real semiaxis", 3rd Dolomites Workshop on Constructive Approximation and Applications, Alba di Canazei (Trento, Italy), September 9-14, 2012.
- "Polynomial approximation on the real semiaxis", IV Jaen Conference on Approximation Theory, Ubeda, Spain, June 23-27, 2013 (Plenary lecture).
- "L^p-convergence of Lagrange and Hermite interpolation", Erdos Centennial, Budapest, Hungary, July 1-5, 2013.
- "Fredholm integral equations on the real semiaxis: a numerical method", Nonlinear Evolution Equations and Linear Algebra, Cagliari, Italy, September 2-5, 2013.
- "Some remarks on Lagrange interpolation in weighted L^p-norm", V Jaen Conference on Approximation Theory, Ubeda, Spain, June 23-26, 2014.
- "Lagrange interpolation at the zeros of Pollaczeck-type polynomials", International Conference on Numerical Analysis and Approximation Theory, Cluj-Napoca, Romania, September 17-20, 2014.
- "Some new interpolation processes", VI Jaen Conference on Approximation Theory, Ubeda, Spain, June 28-July 3, 2015