Alexandru Tudorache
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Alexandru Tudorache has a total of 8 co-authors. Here are the top co-authors by number of shared publications:
- Rodica Luca
Department of Mathematics, Gheorghe Asachi Technical University, 700506 Iasi, Romania
29 shared publications - Johnny Henderson
Baylor Univ, Dept Math, Waco, TX 76798 USA
7 shared publications - Vasile-Ion Manta
Department of Computer Science and Engineering, Faculty of Automatic Control and Computer Engineering, “Gheorghe Asachi” Technical University of Iasi, D. Mangeron 27, 700050 Iasi, Romania
4 shared publications - Simona Caraiman
Faculty of Automatic Control and Computer Engineering, Gheorghe Asachi Technical University of Iaşi, Iaşi, Romania
2 shared publications Adrian Prodan
“Gheorghe Asachi” Technical University Iaşi, Romania, Iaşi, Romania
1 shared publication- Adrian Prodan
Department of Computer Science and Engineering, Faculty of Automatic Control and Computer Engineering, “Gheorghe Asachi” Technical University of Iasi, D. Mangeron 27, 700050 Iasi, Romania
1 shared publication
Latest Publications
- Open Access
- 13 November 2026
- Published by MDPI AG in Fractal and Fractional
- Vol. 10 (11) , 793
On an ω-Riemann–Liouville Fractional Differential Equation on an Infinite Interval
We investigate the existence and multiplicity of positive solutions for an -Riemann–Liouville fractional differential equation on an infinite interval supplemented with nonlocal boundary conditions containing Riemann–Stieltjes integrals and -Riemann–Liouville fractional derivatives of various orders. In the proof of our main results we use the Guo–Krasnosel’skii fixed point theorem and the Leggett–Williams fixed point theorem.- 13 November 2026
- Published by MDPI AG in Fractal and Fractional
- Vol. 10 (11) , 793
Open AccessOn an ω-Riemann–Liouville Fractional Differential Equation on an Infinite Interval
We investigate the existence and multiplicity of positive solutions for an -Riemann–Liouville fractional differential equation on an infinite interval supplemented with nonlocal boundary conditions containing Riemann–Stieltjes integrals and -Riemann–Liouville fractional derivatives of various orders. In the proof of our main results we use the Guo–Krasnosel’skii fixed point theorem and the Leggett–Williams fixed point theorem. - Open Access
- 22 October 2026
- Published by MDPI AG in Preprints.org
On an ω-Riemann-Liouville Fractional Differential Equation on an Infinite Interval
We investigate the existence and multiplicity of positive solutions for an ω-Riemann-Liouville fractional differential equation on an infinite interval supplemented with nonlocal boundary conditions containing Riemann-Stieltjes integrals and ω-Riemann-Liouville fractional derivatives of various orders. In the proof of our main results we use the Guo-Krasnosel’skii fixed point theorem and the Leggett-Williams fixed point theorem.
- 22 October 2026
- Published by MDPI AG in Preprints.org
Open AccessOn an ω-Riemann-Liouville Fractional Differential Equation on an Infinite Interval
We investigate the existence and multiplicity of positive solutions for an ω-Riemann-Liouville fractional differential equation on an infinite interval supplemented with nonlocal boundary conditions containing Riemann-Stieltjes integrals and ω-Riemann-Liouville fractional derivatives of various orders. In the proof of our main results we use the Guo-Krasnosel’skii fixed point theorem and the Leggett-Williams fixed point theorem.
- Open Access
A New Quantum Video Processing Algorithm Based on the NEQR Technique
The main goal of this paper is to present a new way of processing a video file using a combination of multiple quantum methods. The design is built upon the novel enhanced quantum representation technique, NEQR, which is then expanded using ideas such as image segmentation, implemented with the help of one or multiple comparators, binarization and cycle shift. This approach allows us to process all frames in parallel according to the desired parameters—one or more thresholds. A demonstration circuit for the proposed design, using a couple of frames, that sums together all the concepts is implemented using the Python programming language and Qiskit open-source framework, made available by IBM. The circuits are analyzed in the experimental section, using the Simulator component and configured using the noise properties of real devices, where we present different relevant metrics obtained by processing the simulation results.
Open AccessA New Quantum Video Processing Algorithm Based on the NEQR Technique
The main goal of this paper is to present a new way of processing a video file using a combination of multiple quantum methods. The design is built upon the novel enhanced quantum representation technique, NEQR, which is then expanded using ideas such as image segmentation, implemented with the help of one or multiple comparators, binarization and cycle shift. This approach allows us to process all frames in parallel according to the desired parameters—one or more thresholds. A demonstration circuit for the proposed design, using a couple of frames, that sums together all the concepts is implemented using the Python programming language and Qiskit open-source framework, made available by IBM. The circuits are analyzed in the experimental section, using the Simulator component and configured using the noise properties of real devices, where we present different relevant metrics obtained by processing the simulation results.
- Open Access
- 15 October 2025
- Published by MDPI AG in Mathematics
- Vol. 13 (20) , 3292
Positive Solutions for a Semipositone Singular ψ–Riemann–Liouville Fractional Boundary Value Problem
We explore the existence of positive solutions to a –Riemann–Liouville fractional differential equation with a parameter and a sign-changing singular nonlinearity, supplemented with nonlocal boundary conditions which contain Riemann–Stieltjes integrals and various fractional derivatives. To establish our main results, we use the Guo–Krasnosel’skii fixed-point theorem.- 15 October 2025
- Published by MDPI AG in Mathematics
- Vol. 13 (20) , 3292
Open AccessPositive Solutions for a Semipositone Singular ψ–Riemann–Liouville Fractional Boundary Value Problem
We explore the existence of positive solutions to a –Riemann–Liouville fractional differential equation with a parameter and a sign-changing singular nonlinearity, supplemented with nonlocal boundary conditions which contain Riemann–Stieltjes integrals and various fractional derivatives. To establish our main results, we use the Guo–Krasnosel’skii fixed-point theorem. - Open Access
- 13 June 2025
- Published by MDPI AG in Fractal and Fractional
- Vol. 9 (6) , 378
A Hadamard Fractional Boundary Value Problem on an Infinite Interval at Resonance
This paper addresses the existence of solutions to a Hadamard fractional differential equation of arbitrary order on an infinite interval, subject to integral boundary conditions that incorporate both Riemann–Stieltjes integrals and Hadamard fractional derivatives. Due to the presence of nontrivial solutions in the associated homogeneous boundary value problem, the problem is classified as resonant. The Mawhin continuation theorem is utilized to derive the main findings.
- 13 June 2025
- Published by MDPI AG in Fractal and Fractional
- Vol. 9 (6) , 378
Open AccessA Hadamard Fractional Boundary Value Problem on an Infinite Interval at Resonance
This paper addresses the existence of solutions to a Hadamard fractional differential equation of arbitrary order on an infinite interval, subject to integral boundary conditions that incorporate both Riemann–Stieltjes integrals and Hadamard fractional derivatives. Due to the presence of nontrivial solutions in the associated homogeneous boundary value problem, the problem is classified as resonant. The Mawhin continuation theorem is utilized to derive the main findings.
- Open Access
- 14 February 2025
- Published by MDPI AG in Fractal and Fractional
- Vol. 9 (2) , 119
Existence of Solutions for a Hadamard Fractional Boundary Value Problem at Resonance
We explore the existence of solutions for a Hadamard fractional differential equation, subject to nonlocal boundary conditions, which contain Hadamard fractional derivatives and Riemann–Stieltjes integrals. This problem is a resonant one in the sense that the corresponding homogeneous boundary-value problem has nontrivial solutions. In the proof of the main result, we use the Mawhin continuation theorem.
- 14 February 2025
- Published by MDPI AG in Fractal and Fractional
- Vol. 9 (2) , 119
Open AccessExistence of Solutions for a Hadamard Fractional Boundary Value Problem at Resonance
We explore the existence of solutions for a Hadamard fractional differential equation, subject to nonlocal boundary conditions, which contain Hadamard fractional derivatives and Riemann–Stieltjes integrals. This problem is a resonant one in the sense that the corresponding homogeneous boundary-value problem has nontrivial solutions. In the proof of the main result, we use the Mawhin continuation theorem.
- Open Access
- 19 September 2024
- Published by MDPI AG in Fractal and Fractional
- Vol. 8 (9) , 543
Positive Solutions to a System of Coupled Hadamard Fractional Boundary Value Problems
We explore the existence, uniqueness, and multiplicity of positive solutions to a system of Hadamard fractional differential equations that contain fractional integral terms. Defined on a finite interval, this system is subject to general coupled nonlocal boundary conditions encompassing Riemann–Stieltjes integrals and Hadamard fractional derivatives. To establish the main results, we employ several fixed-point theorems, namely the Banach contraction mapping principle, the Schauder fixed-point theorem, the Leggett–Williams fixed-point theorem, and the Guo–Krasnosel’skii fixed-point theorem.
- 19 September 2024
- Published by MDPI AG in Fractal and Fractional
- Vol. 8 (9) , 543
Open AccessPositive Solutions to a System of Coupled Hadamard Fractional Boundary Value Problems
We explore the existence, uniqueness, and multiplicity of positive solutions to a system of Hadamard fractional differential equations that contain fractional integral terms. Defined on a finite interval, this system is subject to general coupled nonlocal boundary conditions encompassing Riemann–Stieltjes integrals and Hadamard fractional derivatives. To establish the main results, we employ several fixed-point theorems, namely the Banach contraction mapping principle, the Schauder fixed-point theorem, the Leggett–Williams fixed-point theorem, and the Guo–Krasnosel’skii fixed-point theorem.
- Open Access
- 27 April 2024
- Published by MDPI AG in Mathematics
- Vol. 12 (9) , 1335
Existence of Solutions to a System of Fractional -Difference Boundary Value ProblemsWe are investigating the existence of solutions to a system of two fractional -difference equations containing fractional -integral terms, subject to multi-point boundary conditions that encompass -derivatives and fractional -derivatives of different orders. In our main results, we rely on various fixed point theorems, such as the Leray–Schauder nonlinear alternative, the Schaefer fixed point theorem, the Krasnosel’skii fixed point theorem for the sum of two operators, and the Banach contraction mapping principle. Finally, several examples are provided to illustrate our findings.- 27 April 2024
- Published by MDPI AG in Mathematics
- Vol. 12 (9) , 1335
Open AccessExistence of Solutions to a System of Fractional -Difference Boundary Value ProblemsWe are investigating the existence of solutions to a system of two fractional -difference equations containing fractional -integral terms, subject to multi-point boundary conditions that encompass -derivatives and fractional -derivatives of different orders. In our main results, we rely on various fixed point theorems, such as the Leray–Schauder nonlinear alternative, the Schaefer fixed point theorem, the Krasnosel’skii fixed point theorem for the sum of two operators, and the Banach contraction mapping principle. Finally, several examples are provided to illustrate our findings. - Open Access
- 11 November 2023
- Published by MDPI AG in Fractal and Fractional
- Vol. 7 (11) , 816
Systems of Hilfer–Hadamard Fractional Differential Equations with Nonlocal Coupled Boundary Conditions
We study the existence and uniqueness of solutions for a system of Hilfer–Hadamard fractional differential equations. These equations are subject to coupled nonlocal boundary conditions that incorporate Riemann–Stieltjes integrals and a range of Hadamard fractional derivatives. To establish our key findings, we apply various fixed point theorems, notably including the Banach contraction mapping principle, the Krasnosel’skii fixed point theorem applied to the sum of two operators, the Schaefer fixed point theorem, and the Leray–Schauder nonlinear alternative.
- 11 November 2023
- Published by MDPI AG in Fractal and Fractional
- Vol. 7 (11) , 816
Open AccessSystems of Hilfer–Hadamard Fractional Differential Equations with Nonlocal Coupled Boundary Conditions
We study the existence and uniqueness of solutions for a system of Hilfer–Hadamard fractional differential equations. These equations are subject to coupled nonlocal boundary conditions that incorporate Riemann–Stieltjes integrals and a range of Hadamard fractional derivatives. To establish our key findings, we apply various fixed point theorems, notably including the Banach contraction mapping principle, the Krasnosel’skii fixed point theorem applied to the sum of two operators, the Schaefer fixed point theorem, and the Leray–Schauder nonlinear alternative.
- Open Access
Positive Solutions for a System of Hadamard Fractional Boundary Value Problems on an Infinite Interval
Our investigation is devoted to examining the existence, uniqueness, and multiplicity of positive solutions for a system of Hadamard fractional differential equations. This system is defined on an infinite interval and is subject to coupled nonlocal boundary conditions. These boundary conditions encompass both Hadamard fractional derivatives and Riemann–Stieltjes integrals, and the nonlinearities within the system are non-negative functions that may not be bounded. To establish the main results, we rely on the utilization of mathematical theorems such as the Schauder fixed-point theorem, the Banach contraction mapping principle, and the Avery–Peterson fixed-point theorem.
Open AccessPositive Solutions for a System of Hadamard Fractional Boundary Value Problems on an Infinite Interval
Our investigation is devoted to examining the existence, uniqueness, and multiplicity of positive solutions for a system of Hadamard fractional differential equations. This system is defined on an infinite interval and is subject to coupled nonlocal boundary conditions. These boundary conditions encompass both Hadamard fractional derivatives and Riemann–Stieltjes integrals, and the nonlinearities within the system are non-negative functions that may not be bounded. To establish the main results, we rely on the utilization of mathematical theorems such as the Schauder fixed-point theorem, the Banach contraction mapping principle, and the Avery–Peterson fixed-point theorem.