Eung Il Ko Professor Emeritus
Eungil Ko is a professor in Department of Mathematics. His own focus is the study of a functional analysis. He got Ph.D. from Indiana University in USA. He has published around 120 papers in SCI(E) Journals. He is especially interested in the structures of operators, the complex symmetric operators, the local spectral theory including the invariant subspace problems, operator theory for composition and weighted composition operators and Toeplitz operators on complex function spaces, and matrix theory.
Research Record
- Remark on square roots of self-adjoint weighted composition operators on H2 Journal of Mathematical Analysis and Applications, 2025, v.543 no.2, 128970
- Expansivity and Contractivity of Toeplitz Operators on Newton Spaces Mediterranean Journal of Mathematics, 2024, v.21 no.2, 57
- H-Toeplitz operators on the function spaces Monatshefte fur Mathematik, 2024, v.205 no.4, 757-786
- Matrix representation of Toeplitz operators on Newton spaces Journal of Inequalities and Applications, 2024, v.2024 no.1, 43
- On C-Normal Operator Matrices Results in Mathematics, 2024, v.79 no.5, 195
- On the generalized Sylvester operator equation AX−Y B = C Linear and Multilinear Algebra, 2024, v.72 no.4, 585-596
- THE OPERATOR EQUATION AXB = X AND THE FUGLEDE-PUTNAM TYPE PROPERTY OPERATORS AND MATRICES, 2024, v.18 no.2, 427-440
- Characterizations of a Complex Symmetric Truncated Backward Shift Type Operator Matrix and its Transforms Results in Mathematics, 2023, v.78 no.1, 13
- Hankel and Toeplitz operators, block matrices and derivations Filomat, 2023, v.37 no.10, 3091-3104
- Hyponormal Toeplitz Operators with Non-harmonic Symbols on the Generalized Derivative Hardy Space Mediterranean Journal of Mathematics, 2023, v.20 no.1, 3
- On properties of C-normal operators II Annals of Functional Analysis, 2023, v.14 no.2, 29
- Properties of Newton polynomials and Toeplitz operators on Newton spaces Annals of Functional Analysis, 2023, v.14 no.3, 55
- Remark on the dilation of truncated Toeplitz operators FILOMAT, 2023, v.37 no.26, 8765-8776
- Remarks on n-power quasinormal operators Filomat, 2023, v.37 no.11, 3371-3381
- Characterizations of Square Roots of Unitary Weighted Composition Operators on H-2 COMPLEX ANALYSIS AND OPERATOR THEORY, 2022, v.16 no.1, 14
- Complex symmetric Toeplitz operators on the generalized derivative Hardy space Journal of Inequalities and Applications, 2022, v.2022 no.1, 74
- Complex symmetric Toeplitz operators on the weighted Bergman space Complex Variables and Elliptic Equations, 2022, v.67 no.6, 1393-1408
- Conjugations and complex symmetric block Toeplitz operators on the weighted Hardy space Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales - Serie A: Matematicas, 2022, v.116 no.1, 18
- ON BACKWARD ALUTHGE ITERATES OF COMPLEX SYMMETRIC OPERATORS MATHEMATICAL INEQUALITIES & APPLICATIONS, 2022, v.25 no.2, 379-395
- On Hyponormality of the Sum of Two Composition Operators FILOMAT, 2022, v.36 no.11, 3561-3572
- Remarks on Composition Operators on the Newton Space MEDITERRANEAN JOURNAL OF MATHEMATICS, 2022, v.19 no.5, 205
- Conjugations and Complex Symmetric Toeplitz Operators on the Weighted Hardy Space Mediterranean Journal of Mathematics, 2021, v.18 no.4, 125
- ON AMPLIATION QUASIAFFINE TRANSFORMS OF OPERATORS BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY, 2021, v.58 no.3, 699-710
- ON QUASINORMALITY OF SINGULAR INTEGRAL OPERATORS WITH CAUCHY KERNEL ON L-2 JOURNAL OF INTEGRAL EQUATIONS AND APPLICATIONS, 2021, v.33 no.1, 77-89
- On Extended Commuting Operators FILOMAT, 2021, v.35 no.3, 883-893
- On local spectral properties of operator matrices JOURNAL OF INEQUALITIES AND APPLICATIONS, 2021, v.2021 no.1, 164
- On properties of C-normal operators BANACH JOURNAL OF MATHEMATICAL ANALYSIS, 2021, v.15 no.4, 65
- Crystal complex symmetric operators BANACH JOURNAL OF MATHEMATICAL ANALYSIS, 2020, v.14 no.4, 1711-1727
- ON OPERATORS T COMMUTING WITH CTC WHERE C IS A CONJUGATION BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY, 2020, v.57 no.1, 69-79
- ON THE ITERATED MEAN TRANSFORMS OF OPERATORS MATHEMATICAL INEQUALITIES & APPLICATIONS, 2020, v.23 no.2, 597-610
- On the generalized mean transforms of complex symmetric operators BANACH JOURNAL OF MATHEMATICAL ANALYSIS, 2020, v.14 no.3, 842-855
- Operator Matrices and Their Weyl Type Theorems FILOMAT, 2020 , 3191-3204
- PROPERTIES OF OPERATOR MATRICES JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY, 2020, v.57 no.4, 893-913
- Remarks on Hyponormal Toeplitz Operators on the Weighted Bergman Spaces Complex Analysis and Operator Theory, 2020, v.14 no.8, 83
- n-FOLD JORDAN PRODUCT COMMUTING MAPS WITH A lambda-ALUTHGE TRANSFORM OPERATORS AND MATRICES, 2020, v.14 no.2, 305-316
- Binormal Toeplitz operators on the Hardy space INTERNATIONAL JOURNAL OF MATHEMATICS, 2019, v.30 no.1, 1950001
- Generalizations of the relation of quasisimilarity for operators Acta Scientiarum Mathematicarum, 2019, v.85 no.3-4, 681-691
- Hyperinvariant subspaces for a class of quasinilpotent operators STUDIA MATHEMATICA, 2019, v.245 no.3, 289-296
- Hyperinvariant subspaces for some 2 × 2 operator matrices, II Kyungpook Mathematical Journal, 2019, v.59 no.2, 225-231
- Hyponormality of Toeplitz operators on the Fock spaces COMPLEX VARIABLES AND ELLIPTIC EQUATIONS, 2019, v.64 no.11, 1825-1843
- Hyponormality of singular Cauchy integral operators with matrix-valued symbols HOKKAIDO MATHEMATICAL JOURNAL, 2019, v.48 no.2, 443-459
- Local Spectral Property of 2 x 2 Operator Matrices FILOMAT, 2019, v.33 no.7, 1845-1854
- Multiplication and Toeplitz Operators on the Generalized Derivative Hardy Space COMPLEX ANALYSIS AND OPERATOR THEORY, 2019, v.13 no.8, 4143-4164
- On Power Similarity of Complex Symmetric Operators FILOMAT, 2019, v.33 no.11, 3577-3586
- On the Dilation of Truncated Toeplitz Operators II Complex Analysis and Operator Theory, 2019, v.13 no.8, 3549-3568
- Remark on complex symmetric operator matrices LINEAR & MULTILINEAR ALGEBRA, 2019, v.67 no.6, 1198-1216
- Skew m-Complex Symmetric Operators FILOMAT, 2019, v.33 no.10, 2975-2983
- m-Isometric block Toeplitz operators Journal of Inequalities and Applications, 2019, v.2019 no.1, 185
- ALMOST INVARIANT HALF-SPACES FOR OPERATORS ON HILBERT SPACE BULLETIN OF THE AUSTRALIAN MATHEMATICAL SOCIETY, 2018, v.97 no.1, 133-140
- ON m-ISOMETRIC TOEPLITZ OPERATORS BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY, 2018, v.55 no.2, 367-378
- On Symmetric and Skew-Symmetric Operators FILOMAT, 2018, v.32 no.1, 293-303
- On operators with similar positive parts Journal of Mathematical Analysis and Applications, 2018, v.463 no.1, 276-293
- On properties of the operator equation TT* = T plus T* FILOMAT, 2018, v.32 no.6, 2247-2256
- REMARKS ON NEARLY EQUIVALENT OPERATORS OPERATORS AND MATRICES, 2018, v.12 no.2, 537-547
- (∞,C)-isometric operators Operators and Matrices, 2017, v.11 no.3, 793-806
- A characterization of binormal matrices Linear and Multilinear Algebra, 2017 , 1-14
- LOCAL SPECTRAL PROPERTY OF RELATIVELY REGULAR OPERATORS MATHEMATICAL INEQUALITIES & APPLICATIONS, 2017, v.20 no.1, 123-137
- ON OPERATORS SATISFYING THE GENERALIZED CAUCHY-SCHWARZ INEQUALITY PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY, 2017, v.145 no.8, 3447-3453
- ON ∞-COMPLEX SYMMETRIC OPERATORS Glasgow Mathematical Journal, 2017 , 1-16
- On Analytic Roots of Hyponormal Operators Mediterranean Journal of Mathematics, 2017, v.14 no.5
- Properties of m-complex symmetric operators Studia Universitatis Babes-Bolyai Mathematica, 2017, v.62 no.2, 233-248
- Weyl Type Theorems for Complex Symmetric Operator Matrices FILOMAT, 2017, v.31 no.9, 2891-2900
- Note on some operator equations and local spectral properties Operators and Matrices, 2016, v.10 no.2, 397-417
- On (m, C)-Isometric Operators Complex Analysis and Operator Theory, 2016, v.10 no.8, 1-16
- On -Complex Symmetric Operators II MEDITERRANEAN JOURNAL OF MATHEMATICS, 2016, v.13 no.5, 3255-3264
- Spectra of some weighted composition operators on H2 Acta Scientiarum Mathematicarum, 2016, v.82 no.42371.0, 221-234
- Characterizations of binormal composition operators with linear fractional symbols on H2 Applied Mathematics and Computation, 2015, v.261, 252-263
- Class A composition operators on H2 Journal of Mathematical Analysis and Applications, 2015, v.435 no.1
- Iterated Aluthge transforms of composition operators on H2 International Journal of Mathematics, 2015, v.26 no.10
- Normal truncated Toeplitz operators on finite-dimensional spaces Linear and Multilinear Algebra, 2015, v.63 no.10, 1947-1971
- On Fuglede–Putnam properties Positivity, 2015
- On Tu-Toeplitzness of weighted composition operators on H2 Complex Variables and Elliptic Equations, 2015, v.60 no.11, 1522-1538
- On backward Aluthge iterates of hyponormal operators Mathematical Inequalities and Applications, 2015, v.18 no.3, 1121-1133
- On complex symmetric Toeplitz operators Journal of Mathematical Analysis and Applications, 2015, v.434 no.1
- On m-Complex Symmetric Operators Mediterranean Journal of Mathematics, 2015, v.13 no.4
- On operators which are power similar to hyponormal operators Osaka Journal of Mathematics, 2015, v.52 no.3, 833-847
- On rank one perturbations of complex symmetric operators Filomat, 2015, v.29 no.8, 1795-1809
- On the Dilation of Truncated Toeplitz Operators Complex Analysis and Operator Theory, 2015, v.10 no.4
- Paranormal operators and some operator equations Filomat, 2015, v.29 no.6, 1195-1207
- Remarks on Complex Symmetric Operators Mediterranean Journal of Mathematics, 2015
- Skew complex symmetric operators and Weyl type theorems Bulletin of the Korean Mathematical Society, 2015, v.52 no.4, 1269-1283
- Subscalarity of operator transforms Mathematische Nachrichten, 2015, v.288 no.17-18
- Commutators of weighted composition operators INTERNATIONAL JOURNAL OF MATHEMATICS, 2014, v.25 no.6
- Complex symmetric weighted composition operators on H-2(D) JOURNAL OF FUNCTIONAL ANALYSIS, 2014, v.267 no.2, 323-351
- Composition operators for which and commute Complex Variables and Elliptic Equations, 2014, v.59 no.12, 1608-1625
- Erratum to Self-commutators of invertible weighted composition operators on H2 Complex Variables and Elliptic Equations, 2014, v.59 no.5, 750
- Operator equations and subscalarity Studia Mathematica, 2014, v.225 no.2, 97-113
- PROPERTIES OF COMPLEX SYMMETRIC OPERATORS OPERATORS AND MATRICES, 2014, v.8 no.4, 957-974
- Self-commutators of invertible weighted composition operators on H-2 COMPLEX VARIABLES AND ELLIPTIC EQUATIONS, 2014, v.59 no.5, 693-705
- Transitivity and structure of operator algebras with a metric property INDAGATIONES MATHEMATICAE-NEW SERIES, 2014, v.25 no.1, 1-23
- WEAK FORMS OF SUPERCYCLITY AND A CLASS OF PARANORMAL OPERATORS MATHEMATICAL INEQUALITIES & APPLICATIONS, 2014, v.17 no.3, 831-842
- [학술지논문] Characterizations of a Complex Symmetric Truncated Backward Shift Type Operator Matrix and its Transforms RESULTS IN MATHEMATICS, 2023, v.78 no.1 , 1-18
- [학술지논문] Hankel and Toeplitz operators, block matrices and derivations FILOMAT, 2023, v.37 no.10 , 3091-3104
- [학술지논문] Hyponormal Toeplitz Operators with Non-harmonic Symbols on the Generalized Derivative Hardy Space MEDITERRANEAN JOURNAL OF MATHEMATICS, 2023, v.20 no.1 , 1-16
- [학술지논문] On properties of C-normal operators II ANNALS OF FUNCTIONAL ANALYSIS, 2023, v.14 no.2 , 1-12
- [학술지논문] Remarks on n-power quasinormal operators Filomat, 2023, v.37 no.11 , 3371-3381
- [학술지논문] (m, C)-Isometric Toeplitz operators with rational symbols LINEAR & MULTILINEAR ALGEBRA, 2022, v.70 no.19 , 4360-4376
- [학술지논문] Characterizations of Square Roots of Unitary Weighted Composition Operators on H-2 COMPLEX ANALYSIS AND OPERATOR THEORY, 2022, v.16 no.1 , 14-14
- [학술지논문] Complex symmetric Toeplitz operators on the generalized derivative Hardy space JOURNAL OF INEQUALITIES AND APPLICATIONS, 2022, v.2022 no.74 , 74-74
- [학술지논문] Complex symmetric Toeplitz operators on the weighted Bergman space COMPLEX VARIABLES AND ELLIPTIC EQUATIONS, 2022, v.67 no.6 , 1393-1408
- [학술지논문] Conjugations and complex symmetric block Toeplitz operators on the weighted Hardy space REVISTA DE LA REAL ACADEMIA DE CIENCIAS EXACTAS FISICAS Y NATURALES SERIE A-MATEMATICAS, 2022, v.116 no.1 , 18-18
- [학술지논문] ON BACKWARD ALUTHGE ITERATES OF COMPLEX SYMMETRIC OPERATORS MATHEMATICAL INEQUALITIES & APPLICATIONS, 2022, v.25 no.2 , 379-395
- [학술지논문] ON QUASINORMALITY OF THE DILATION OF TRUNCATED TOEPLITZ OPERATORS MATHEMATICAL INEQUALITIES & APPLICATIONS, 2022, v.25 no.3 , 679-690
- [학술지논문] On Hyponormality of the Sum of Two Composition Operators FILOMAT, 2022, v.36 no.11 , 3561-3572
- [학술지논문] On solutions of operator equations satisfying the similarity of real and positive parts LINEAR & MULTILINEAR ALGEBRA, 2022, v.70 no.17 , 3271-3286
- [학술지논문] Remarks on Composition Operators on the Newton Space MEDITERRANEAN JOURNAL OF MATHEMATICS, 2022, v.19 no.5 , 205-205
- [학술지논문] Remarks on complex symmetric Toeplitz operators LINEAR & MULTILINEAR ALGEBRA, 2022, v.70 no.18 , 3466-3476
- [학술지논문] Conjugations and Complex Symmetric Toeplitz Operators on the Weighted Hardy Space MEDITERRANEAN JOURNAL OF MATHEMATICS, 2021, v.18 no.4 , 125-125
- [학술지논문] Hyponormality of the dilation of truncated Toeplitz operators COMPLEX VARIABLES AND ELLIPTIC EQUATIONS, 2021, v.66 no.10 , 1664-1675
- [학술지논문] ON AMPLIATION QUASIAFFINE TRANSFORMS OF OPERATORS BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY, 2021, v.58 no.3 , 699-710
- [학술지논문] ON QUASINORMALITY OF SINGULAR INTEGRAL OPERATORS WITH CAUCHY KERNEL ON L-2 JOURNAL OF INTEGRAL EQUATIONS AND APPLICATIONS, 2021, v.33 no.1 , 77-89
- [학술지논문] On Extended Commuting Operators FILOMAT, 2021, v.35 no.3 , 883-893
- [학술지논문] On local spectral properties of operator matrices JOURNAL OF INEQUALITIES AND APPLICATIONS, 2021, v.2021 no.1 , 164-164
- [학술지논문] On properties of C-normal operators BANACH JOURNAL OF MATHEMATICAL ANALYSIS, 2021, v.15 no.4 , 65-65
- [학술지논문] Operators commuting with self-adjoint weighted composition operators on H-2 COMPLEX VARIABLES AND ELLIPTIC EQUATIONS, 2021, v.66 no.12 , 2076-2089
- [학술지논문] Crystal complex symmetric operators BANACH JOURNAL OF MATHEMATICAL ANALYSIS, 2020, v.14 no.4 , 1711-1727
- [학술지논문] ON OPERATORS T COMMUTING WITH CTC WHERE C IS A CONJUGATION BULLETIN OF THE KOREAN MATHEMATICAL SOCIETY, 2020, v.57 no.1 , 69-79
- [학술지논문] ON THE ITERATED MEAN TRANSFORMS OF OPERATORS MATHEMATICAL INEQUALITIES & APPLICATIONS, 2020, v.23 no.2 , 597-610
- [학술지논문] On the generalized mean transforms of complex symmetric operators BANACH JOURNAL OF MATHEMATICAL ANALYSIS, 2020, v.14 no.3 , 842-855
- [학술지논문] Operator Matrices and Their Weyl Type Theorems FILOMAT, 2020, v.34 no.10 , 3191-3204
- [학술지논문] PROPERTIES OF OPERATOR MATRICES JOURNAL OF THE KOREAN MATHEMATICAL SOCIETY, 2020, v.57 no.4 , 893-913
- [학술지논문] Remarks on Hyponormal Toeplitz Operators on the Weighted Bergman Spaces COMPLEX ANALYSIS AND OPERATOR THEORY, 2020, v.14 no.8 , 83-102
- [학술지논문] n-FOLD JORDAN PRODUCT COMMUTING MAPS WITH A lambda-ALUTHGE TRANSFORM OPERATORS AND MATRICES, 2020, v.14 no.2 , 305-316
- [학술발표] Remark on polynomial similarity of operators 2022년도 대한수학회 봄 연구 발표회, 대한민국, 2022-04-28 봄 연구발표회 초록집, 2022
- [학술발표] Topic on generalized Sylvester operator equation AX-YB=C 2022년도 대한수학회 봄 연구 발표회, 대한민국, 2022-04-28 봄 연구발표회 초록집, 2022
- [학술발표] On properties of C-normal operators 2021년도 대한수학회 가을 연구 발표회, 대한민국, 2021-10-21 가을연구발표회 초록집, 2021
- [학술발표] On rank one perturbations of normal operators and their local spectral properties 2021년도 대한수학회 가을 연구 발표회, 대한민국, 2021-10-21 가을연구발표회 초록집, 2021
- [학술발표] Hyponormal Toeplitz operators on the Newton spaces 대한수학회 가을 연구 발표회, 대한민국, 2020-10-23 대한수학회 가을 연구 발표회, 2020
- [학술발표] On backward Aluthge iterates of complex symmetric operators 대한수학회 가을 연구 발표회, 대한민국, 2020-10-23 대한수학회 가을 연구 발표회, 2020
- [학술발표] Properties of multiplication and Toeplitz operators on the generalized derivative Hardy space 대한수학회 봄 연구 발표회, 대한민국, 2020-07-03 대한수학회 봄 연구 발표회, 2020
- [학술발표] Quasinormality of singular integral operators 대한수학회 가을 연구 발표회, 대한민국, 2020-10-23 대한수학회 가을 연구 발표회, 2020
- [학술발표] Remarks on hyponormal Toeplitz operators on the weighted bergman spaces 대한수학회 봄 연구 발표회, 대한민국, 2020-07-03 대한수학회 봄 연구 발표회, 2020
- [학술발표] Remarks on n-power quasinormal operator 대한수학회 봄 연구 발표회, 대한민국, 2020-07-03 대한수학회 봄 연구발표회, 2020
- [학술발표] Square roots of unitary weighted composition operators on H^2 대한수학회 가을 연구 발표회, 대한민국, 2020-10-23 대한수학회 가을 연구 발표회, 2020
- [학술발표] properties of operators with similar both real and positive parts 대한수학회 봄 연구 발표회, 대한민국, 2020-07-03 대한수학회 봄 연구 발표회, 2020
Courses
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2023-1st
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Calculus 강의 계획서 상세보기
- Subject No 20406Class No 01
- 1Year ( 3Credit , 3Hour) Mon 3~3 (POSCO452) , Wed 2~2 (POSCO452)
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Complex Analysis I 강의 계획서 상세보기
- Subject No 35291Class No 01
- 3Year ( 3Credit , 3Hour) Mon 5~5 (POSCO361) , Wed 4~4 (POSCO361)
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2022-2nd
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Calculus
- Subject No 20406Class No 01
- 1Year ( 3Credit , 3Hour) Mon 3~3 (POSCO363) , Wed 2~2 (POSCO363)
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Complex Analysis II
- Subject No 35292Class No 01
- 3Year ( 3Credit , 3Hour) Mon 5~5 (POSCO452) , Wed 4~4 (POSCO452)
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