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## Popa, Constantin Gh.

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 Author ID: popa.constantin-gh Published as: Popa, Constantin; Popa, C.; Popa, C. G.; Popa, Const. Gh.; Popa, Constantin Gh. Homepage: http://www.ima.ro/people/cpopa.html External Links: ORCID · Google Scholar · ResearchGate · dblp
 Documents Indexed: 110 Publications since 1959, including 1 Book Reviewing Activity: 586 Reviews
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#### Co-Authors

 58 single-authored 9 Nicola, Aurelian 9 Rüde, Ulrich 6 Juncu, Gheorghe 5 Carp, Doina 4 Preclik, Tobias 3 Golubovici, Gabriel 3 Pelican, Elena 3 Petra, Stefania 2 Jebelean, Petru 2 Mohr, Marcus 2 Pantelimon, Ioana 2 Petcu, Dana 2 Pomparău, Ioana 2 Serban, Cristina 1 Aniculaesei, Gheorghe 1 Barbu, Viorel 1 Bobe, Alexandru 1 Bucevschi, Mircea Dan 1 Censor, Yair 1 Da Prato, Giuseppe 1 Dumitrasc, Andrei 1 Evans, David John 1 Gheorghiu, Gheorghe Th. 1 Graf, M. 1 Grecu, Lăcrămioara 1 Köstler, Harald 1 Leleux, Philippe 1 Mosekilde, Erik 1 Nicolescu, Bogdan-Nicuşor 1 Peterfi, L. 1 Ruiz, Daniel 1 Schnörr, Christoph 1 Serban, Calin-Constantin 1 Sharaniuk, A. V. 1 Udrescu, Tudor 1 Zdunek, Rafal
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#### Serials

 12 International Journal of Computer Mathematics 8 Analele Ştiinţifice ale Universităţii “Ovidius” Constanţa. Seria: Matematică 7 Numerical Algorithms 6 Lucrările Ştienţifice ale Institutului Pedagogie Timişoara. Matematică-Fizică 5 Mathematics and Computers in Simulation 5 Studii şi Cercetări Matematice 5 Carpathian Journal of Mathematics 4 Analele Universitaţii din Timişoara. Seria Ştiinţe Matematice-Fizice 3 BIT 3 Linear Algebra and its Applications 3 Revue d’Analyse Numérique et de Théorie de l’Approximation 3 The Korean Journal of Computational & Applied Mathematics 2 Applied Mathematics and Computation 2 Analele Universităţii din Timişoara. Seria Matematică-Informatică 2 Buletinul Ştiinţific al Universităţii Politehnica din Timişoara. Seria Matematică-Fizică 2 ZAMM. Zeitschrift für Angewandte Mathematik und Mechanik 2 Proceedings of the Romanian Academy. Series A: Mathematics, Physics, Technical Sciences, Information Science 2 Advanced Modeling and Optimization 2 PAMM. Proceedings in Applied Mathematics and Mechanics 2 ROMAI Journal 2 Annals of the Academy of Romanian Scientists. Mathematics and its Applications 1 Inverse Problems 1 Revue Roumaine de Mathématiques Pures et Appliquées 1 Analele Universității București. Matematică 1 Analele Universităţii din Timişoara. Ştiinţe Matematice 1 Annales Polonici Mathematici 1 Applied Numerical Mathematics 1 Buletinul Institutului Politehnic din Iaşi. Secţia I 1 Revue Roumaine des Sciences Techniques. Série de Mécanique Appliquée 1 Studia Universitatis Babeş-Bolyai. Mathematica 1 Bollettino della Unione Matemàtica Italiana. Serie VII. B 1 SIAM Journal on Scientific Computing 1 ETNA. Electronic Transactions on Numerical Analysis 1 NoDEA. Nonlinear Differential Equations and Applications 1 Analele Universităţii “Ovidius” Constanţa. Seria: Matematică 1 Computer Science Journal of Moldova 1 Academia Republicii Populare Romîne, Studii Şi Cercetări Matematice 1 Monografii Matematice (Timişoara) 1 Inverse Problems and Imaging 1 Journal of Applied Mathematics & Informatics 1 Nonlinear Analysis. Theory, Methods & Applications
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#### Fields

 89 Numerical analysis (65-XX) 14 Partial differential equations (35-XX) 8 Information and communication theory, circuits (94-XX) 6 Linear and multilinear algebra; matrix theory (15-XX) 6 Difference and functional equations (39-XX) 6 Integral equations (45-XX) 4 Operator theory (47-XX) 4 Operations research, mathematical programming (90-XX) 3 Ordinary differential equations (34-XX) 3 Computer science (68-XX) 3 Systems theory; control (93-XX) 2 Calculus of variations and optimal control; optimization (49-XX) 2 Mechanics of particles and systems (70-XX) 2 Fluid mechanics (76-XX) 2 Biology and other natural sciences (92-XX) 1 Combinatorics (05-XX) 1 Group theory and generalizations (20-XX) 1 Approximations and expansions (41-XX) 1 Functional analysis (46-XX) 1 Mechanics of deformable solids (74-XX)

#### Citations contained in zbMATH Open

42 Publications have been cited 167 times in 103 Documents Cited by Year
Extensions of block-projections methods with relaxation parameters to inconsistent and rank-deficient least-squares problems. Zbl 1005.65038
Popa, Constantin
1998
Sur l’équation fonctionnelle $$f(x+yf(x)) = f(x)f(y)$$. Zbl 0141.32804
Popa, C. G.
1965
Least-squares solution of overdetermined inconsistent linear systems using Kaczmarz’s relaxation. Zbl 0830.65027
Popa, Constantin
1995
Convergence rates for Kaczmarz-type algorithms. Zbl 1398.65049
Popa, Constantin
2018
Single projection Kaczmarz extended algorithms. Zbl 1376.65062
Petra, Stefania; Popa, Constantin
2016
On Kaczmarz’s projection iteration as a direct solver for linear least squares problems. Zbl 1238.65031
Popa, C.; Preclik, T.; Köstler, H.; Rüde, U.
2012
A fast Kaczmarz-Kovarik algorithm for consistent least-squares problems. Zbl 0970.65036
Popa, Constantin
2001
Existence and uniqueness of the dynamic programming equation in Hilbert space. Zbl 0508.49024
Barbu, V.; Da Prato, G.; Popa, C.
1983
A Kaczmarz-Kovarik algorithm for symmetric ill-conditioned matrices. Zbl 1120.65318
Popa, Constantin
2004
Block-projections algorithms with blocks containing mutually orthogonal rows and columns. Zbl 1126.65307
Popa, Constantin
1999
Extended and constrained diagonal weighting algorithm with application to inverse problems in image reconstruction. Zbl 1191.94022
Popa, Constantin
2010
Characterization of the solutions set of inconsistent least-squares problems by an extended Kaczmarz algorithm. Zbl 0920.65023
Popa, Constantin
1999
Mesh independence of the condition number of discrete Galerkin systems by preconditioning. Zbl 0828.65053
Popa, Constantin
1994
Preconditioning conjugate gradient method for nonsymmetric systems. Zbl 0846.65010
Popa, Constantin
1995
A method for improving orthogonality of rows and columns of matrices. Zbl 1005.65039
Popa, Constantin
2001
Projections and preconditioning for inconsistent least-squares problems. Zbl 1005.65037
Evans, David J.; Popa, Constantin
2001
Extension of an approximate orthogonalization algorithm to arbitrary rectangular matrices. Zbl 1016.65021
Popa, Constantin
2001
Penalized least-squares image reconstruction for borehole tomography. Zbl 1182.94007
Popa, Constantin; Zdunek, Rafal
2005
A hybrid Kaczmarz-conjugate gradient algorithm for image reconstruction. Zbl 1194.94038
Popa, Constantin
2010
Han-type algorithms for inconsistent systems of linear inequalities – a unified approach. Zbl 1338.65163
Popa, C.; Şerban, C.
2014
Preconditioning by gram matrix approximation for diffusion-convection-reaction equations with discontinuous coefficients. Zbl 1005.68044
Juncu, Gh.; Popa, C.
2002
Modified Kovarik algorithm for approximate orthogonalization of arbitrary matrices. Zbl 1022.65045
Popa, Constantin
2003
Preconditioning by approximations of the Gram matrix for convection-diffusion equations. Zbl 0930.65028
Juncu, Gh.; Popa, C.
1998
Family constraining of iterative algorithms. Zbl 1297.65056
Censor, Yair; Pantelimon, Ioana; Popa, Constantin
2014
A general extending and constraining procedure for linear iterative methods. Zbl 1256.65027
Nicola, Aurelian; Petra, Stefania; Popa, Constantin; Schnörr, Christoph
2012
Hamilton-Jacobi equations and synthesis of optimal bilinear controls in Hilbert spaces. Zbl 0647.93039
Aniculaesei, G.; Popa, C.
1987
Constrained Kaczmarz extended algorithm for image reconstruction. Zbl 1157.65022
Popa, Constantin
2008
Interpolation and related coarsening techniques for the algebraic multigrid method. Zbl 0809.65116
Golubovici, G.; Popa, C.
1994
An iterative algorithm for approximate orthogonalisation of symmetric matrices. Zbl 1053.65029
Mohr, M.; Popa, C.; Rüde, U.
2004
Constrained SART algorithm for inverse problems in image reconstruction. Zbl 1272.65033
Grecu, Lacramioara; Popa, Constantin
2013
Regularized solution of LCP problems with application to rigid body dynamics. Zbl 1322.65069
Popa, Constantin; Preclik, Tobias; Rüde, Ulrich
2015
Kaczmarz extended versus augmented system solution in image reconstruction. Zbl 1265.65068
Nicola, Aurelian; Popa, Constantin
2010
Direct and iterative Kaczmarz-like solvers. Zbl 1073.65522
Popa, Constantin
2002
A new version of Kovarik’s approximate orthogonalization algorithm without matrix inversion. Zbl 1085.65038
Petcu, D.; Popa, C.
2005
Algebraic multigrid smoothing property of Kaczmarz’s relaxation for general rectangular linear systems. Zbl 1188.65036
Popa, Constantin
2008
Constraining by a family of strictly nonexpansive idempotent functions with applications in image reconstruction. Zbl 1273.65035
Pantelimon, Ioana; Popa, Constantin
2013
Supplementary projections for the acceleration of Kaczmarz algorithm. Zbl 1410.65117
Pomparău, I.; Popa, C.
2014
A note on Kaczmarz algorithm with remotest set control sequence. Zbl 1438.65054
Popa, Constantin
2018
On remotest set and random controls in Kaczmarz algorithm. Zbl 1438.65055
Popa, Constantin
2018
Modified Han algorithm for inconsistent linear inequalities. Zbl 1349.65192
Carp, Doina; Popa, Constantin; Serban, Cristina
2015
Numerical extremal solutions for a mixed problem with singular $${\phi}$$-Laplacian. Zbl 1305.34037
Jebelean, Petru; Popa, Constantin; Şerban, Călin
2014
Numerical solutions to singular $$\phi$$-Laplacian with Dirichlet boundary conditions. Zbl 1323.65084
Jebelean, Petru; Popa, Constantin
2014
Convergence rates for Kaczmarz-type algorithms. Zbl 1398.65049
Popa, Constantin
2018
A note on Kaczmarz algorithm with remotest set control sequence. Zbl 1438.65054
Popa, Constantin
2018
On remotest set and random controls in Kaczmarz algorithm. Zbl 1438.65055
Popa, Constantin
2018
Single projection Kaczmarz extended algorithms. Zbl 1376.65062
Petra, Stefania; Popa, Constantin
2016
Regularized solution of LCP problems with application to rigid body dynamics. Zbl 1322.65069
Popa, Constantin; Preclik, Tobias; Rüde, Ulrich
2015
Modified Han algorithm for inconsistent linear inequalities. Zbl 1349.65192
Carp, Doina; Popa, Constantin; Serban, Cristina
2015
Han-type algorithms for inconsistent systems of linear inequalities – a unified approach. Zbl 1338.65163
Popa, C.; Şerban, C.
2014
Family constraining of iterative algorithms. Zbl 1297.65056
Censor, Yair; Pantelimon, Ioana; Popa, Constantin
2014
Supplementary projections for the acceleration of Kaczmarz algorithm. Zbl 1410.65117
Pomparău, I.; Popa, C.
2014
Numerical extremal solutions for a mixed problem with singular $${\phi}$$-Laplacian. Zbl 1305.34037
Jebelean, Petru; Popa, Constantin; Şerban, Călin
2014
Numerical solutions to singular $$\phi$$-Laplacian with Dirichlet boundary conditions. Zbl 1323.65084
Jebelean, Petru; Popa, Constantin
2014
Constrained SART algorithm for inverse problems in image reconstruction. Zbl 1272.65033
Grecu, Lacramioara; Popa, Constantin
2013
Constraining by a family of strictly nonexpansive idempotent functions with applications in image reconstruction. Zbl 1273.65035
Pantelimon, Ioana; Popa, Constantin
2013
On Kaczmarz’s projection iteration as a direct solver for linear least squares problems. Zbl 1238.65031
Popa, C.; Preclik, T.; Köstler, H.; Rüde, U.
2012
A general extending and constraining procedure for linear iterative methods. Zbl 1256.65027
Nicola, Aurelian; Petra, Stefania; Popa, Constantin; Schnörr, Christoph
2012
Extended and constrained diagonal weighting algorithm with application to inverse problems in image reconstruction. Zbl 1191.94022
Popa, Constantin
2010
A hybrid Kaczmarz-conjugate gradient algorithm for image reconstruction. Zbl 1194.94038
Popa, Constantin
2010
Kaczmarz extended versus augmented system solution in image reconstruction. Zbl 1265.65068
Nicola, Aurelian; Popa, Constantin
2010
Constrained Kaczmarz extended algorithm for image reconstruction. Zbl 1157.65022
Popa, Constantin
2008
Algebraic multigrid smoothing property of Kaczmarz’s relaxation for general rectangular linear systems. Zbl 1188.65036
Popa, Constantin
2008
Penalized least-squares image reconstruction for borehole tomography. Zbl 1182.94007
Popa, Constantin; Zdunek, Rafal
2005
A new version of Kovarik’s approximate orthogonalization algorithm without matrix inversion. Zbl 1085.65038
Petcu, D.; Popa, C.
2005
A Kaczmarz-Kovarik algorithm for symmetric ill-conditioned matrices. Zbl 1120.65318
Popa, Constantin
2004
An iterative algorithm for approximate orthogonalisation of symmetric matrices. Zbl 1053.65029
Mohr, M.; Popa, C.; Rüde, U.
2004
Modified Kovarik algorithm for approximate orthogonalization of arbitrary matrices. Zbl 1022.65045
Popa, Constantin
2003
Preconditioning by gram matrix approximation for diffusion-convection-reaction equations with discontinuous coefficients. Zbl 1005.68044
Juncu, Gh.; Popa, C.
2002
Direct and iterative Kaczmarz-like solvers. Zbl 1073.65522
Popa, Constantin
2002
A fast Kaczmarz-Kovarik algorithm for consistent least-squares problems. Zbl 0970.65036
Popa, Constantin
2001
A method for improving orthogonality of rows and columns of matrices. Zbl 1005.65039
Popa, Constantin
2001
Projections and preconditioning for inconsistent least-squares problems. Zbl 1005.65037
Evans, David J.; Popa, Constantin
2001
Extension of an approximate orthogonalization algorithm to arbitrary rectangular matrices. Zbl 1016.65021
Popa, Constantin
2001
Block-projections algorithms with blocks containing mutually orthogonal rows and columns. Zbl 1126.65307
Popa, Constantin
1999
Characterization of the solutions set of inconsistent least-squares problems by an extended Kaczmarz algorithm. Zbl 0920.65023
Popa, Constantin
1999
Extensions of block-projections methods with relaxation parameters to inconsistent and rank-deficient least-squares problems. Zbl 1005.65038
Popa, Constantin
1998
Preconditioning by approximations of the Gram matrix for convection-diffusion equations. Zbl 0930.65028
Juncu, Gh.; Popa, C.
1998
Least-squares solution of overdetermined inconsistent linear systems using Kaczmarz’s relaxation. Zbl 0830.65027
Popa, Constantin
1995
Preconditioning conjugate gradient method for nonsymmetric systems. Zbl 0846.65010
Popa, Constantin
1995
Mesh independence of the condition number of discrete Galerkin systems by preconditioning. Zbl 0828.65053
Popa, Constantin
1994
Interpolation and related coarsening techniques for the algebraic multigrid method. Zbl 0809.65116
Golubovici, G.; Popa, C.
1994
Hamilton-Jacobi equations and synthesis of optimal bilinear controls in Hilbert spaces. Zbl 0647.93039
Aniculaesei, G.; Popa, C.
1987
Existence and uniqueness of the dynamic programming equation in Hilbert space. Zbl 0508.49024
Barbu, V.; Da Prato, G.; Popa, C.
1983
Sur l’équation fonctionnelle $$f(x+yf(x)) = f(x)f(y)$$. Zbl 0141.32804
Popa, C. G.
1965
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#### Cited by 124 Authors

 22 Popa, Constantin Gh. 9 Needell, Deanna 7 Ostaszewski, Adam J. 5 Abbasi, Mokhtar 5 Nikazad, Touraj 4 Bingham, Nicholas Hugh 3 Echebest, Nélida E. 3 Elfving, Tommy 3 Faggian, Silvia 3 Goberna, Miguel Angel 3 Gozzi, Fausto 3 Guardarucci, M. T. 3 Haddock, Jamie 3 Jabłońska, Eliza 3 Juncu, Gheorghe 3 Rüde, Ulrich 3 Scolnik, Hugo D. 2 Bai, Zhongzhi 2 Chudziak, Jacek 2 Kang, Chuangang 2 Loizou, Nicolas 2 Ma, Anna 2 Mohr, Marcus 2 Pantelimon, Ioana 2 Petra, Stefania 2 Preclik, Tobias 2 Ramdas, Aaditya K. 2 Richtárik, Peter 2 Steinerberger, Stefan 2 Volle, Michel 1 Aczél, János Dezső 1 Aniculaesei, Gheorghe 1 Barbu, Viorel 1 Bilić, Nataša 1 Briskman, Jonathan 1 Cabada, Alberto 1 Censor, Yair 1 Chen, Jiaqi 1 Chung, Julianne M. 1 Chung, Matthias 1 Davideanu, Cătălina 1 De Loera, Jesús A. 1 Dhombres, Jean G. 1 Du, Kui 1 Du, Yishu 1 Dumitrescu, Bogdan Alexandru 1 Eibl, Sebastian 1 Esmaeili, Hamid 1 Evans, David John 1 Fabbri, Giorgio 1 Favini, Angelo 1 Gower, Robert Mansel 1 Guan, Ying-Jun 1 Guo, Yumeng 1 Hansen, Per Christian 1 Hayami, Ken 1 Hefny, Ahmed 1 Henson, Van Emden 1 Herman, Gabor T. 1 Hiriart-Urruty, Jean-Baptiste 1 Hochstenbach, Michiel E. 1 Huang, Zhengda 1 Islam, Md. Saiful 1 Ivanov, Andreĭ Aleksandrovich 1 Jebelean, Petru 1 Jørgensen, Palle E. T. 1 Karimpour, Mehdi 1 Kisela, Tomáš 1 Köstler, Harald 1 Li, Weiguo 1 Lin, Chuan 1 Liu, Ji 1 Liu, Xinguo 1 López-Cerdá, Marco Antonio 1 Meier Yang, Ulrike 1 Mirzapour, Mahdi 1 Molitor, Denali 1 Moorman, Jacob D. 1 Morikuni, Keiichi 1 Morshed, Muhammad Sarowar 1 Motreanu, Dumitru 1 Mureńko, Anna 1 Nicola, Aurelian 1 Noor-E-Alam, Muhammad 1 Petcu, Dana 1 Pomparău, Ioana 1 Pralat, Andrzej 1 Qiao, Tiantian 1 Schnörr, Christoph 1 Seidman, Thomas I. 1 Serban, Calin-Constantin 1 Si, Wu-Tao 1 Slagel, J. Tanner 1 Song, Myung-Sin 1 Srebro, Nathan 1 Steinbach, Olaf 1 Sun, Xiaohui 1 Tenorio, Luis 1 Tian, James F. 1 Tropp, Joel A. ...and 24 more Authors
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#### Cited in 50 Serials

 8 International Journal of Computer Mathematics 7 Linear Algebra and its Applications 6 SIAM Journal on Scientific Computing 5 Journal of Mathematical Analysis and Applications 5 BIT 5 Aequationes Mathematicae 4 Mathematics and Computers in Simulation 4 Numerical Algorithms 3 Applied Mathematics and Computation 3 Journal of Computational and Applied Mathematics 2 Inverse Problems 2 Mathematics of Computation 2 Calcolo 2 SIAM Journal on Matrix Analysis and Applications 2 Mathematical Programming. Series A. Series B 2 Indagationes Mathematicae. New Series 2 Computational Optimization and Applications 2 Journal of Inverse and Ill-Posed Problems 2 International Transactions in Operational Research 2 Mathematical Population Studies 1 Computers & Mathematics with Applications 1 Journal of the Franklin Institute 1 Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg 1 Applied Mathematics and Optimization 1 Archiv der Mathematik 1 Journal of Mathematical Economics 1 Journal of Optimization Theory and Applications 1 Mathematica Slovaca 1 Nonlinear Analysis. Theory, Methods & Applications. Series A: Theory and Methods 1 Numerische Mathematik 1 Quarterly of Applied Mathematics 1 Rendiconti del Seminario Matematico della Università di Padova 1 SIAM Journal on Numerical Analysis 1 Acta Mathematica Hungarica 1 Applied Numerical Mathematics 1 Computational Mechanics 1 Applied Mathematics Letters 1 Journal of Global Optimization 1 Journal of Mathematical Imaging and Vision 1 International Journal of Numerical Methods for Heat & Fluid Flow 1 NoDEA. Nonlinear Differential Equations and Applications 1 Vietnam Journal of Mathematics 1 Optimization Methods & Software 1 Communications in Nonlinear Science and Numerical Simulation 1 Applied Mathematics E-Notes 1 Discrete and Continuous Dynamical Systems. Series S 1 Set-Valued and Variational Analysis 1 Nonlinear Analysis. Theory, Methods & Applications 1 Advances in Operator Theory 1 SIAM Journal on Mathematics of Data Science
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#### Cited in 30 Fields

 68 Numerical analysis (65-XX) 21 Operations research, mathematical programming (90-XX) 17 Linear and multilinear algebra; matrix theory (15-XX) 14 Difference and functional equations (39-XX) 13 Computer science (68-XX) 10 Calculus of variations and optimal control; optimization (49-XX) 9 Information and communication theory, circuits (94-XX) 6 Partial differential equations (35-XX) 5 Real functions (26-XX) 5 Operator theory (47-XX) 4 Ordinary differential equations (34-XX) 3 Measure and integration (28-XX) 3 Approximations and expansions (41-XX) 3 Functional analysis (46-XX) 3 Probability theory and stochastic processes (60-XX) 3 Mechanics of particles and systems (70-XX) 3 Game theory, economics, finance, and other social and behavioral sciences (91-XX) 3 Biology and other natural sciences (92-XX) 2 Dynamical systems and ergodic theory (37-XX) 2 Integral transforms, operational calculus (44-XX) 2 Integral equations (45-XX) 2 Systems theory; control (93-XX) 1 Group theory and generalizations (20-XX) 1 Special functions (33-XX) 1 Harmonic analysis on Euclidean spaces (42-XX) 1 Abstract harmonic analysis (43-XX) 1 Convex and discrete geometry (52-XX) 1 Global analysis, analysis on manifolds (58-XX) 1 Mechanics of deformable solids (74-XX) 1 Fluid mechanics (76-XX)