PROGRAM

Professor Yongguang Yu

Title : Qualitative analysis and control research of fractional order systems
with stochastic noises

Session : To be scheduled
School of Mathematics and Statistics, Beijing Jiaotong University, China

Bio : Yongguang Yu received the Ph.D. degree at the Institute of Applied Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, China, in 2004. Since 2010, he has been a professor with the School of Mathematics and Statistics, Beijing Jiaotong University, China. He is currently mainly engaged in the research of complex networks, neural network computing, and the qualitative theory of fractional differential equations. As the first author, he has published 2 academic monographs, and as the first author or corresponding author, he has published more than 200 academic papers, including more than 160 papers indexed in Web of Science (SCI). His papers have been cited more than 5,000 times on Google Scholar. From 2014 to 2024, he was consecutively selected into the Elsevier ‘Computer Science’ field of China’s Highly Cited Scholars list. He has been recognized as one of the top 2% of scientists globally by Stanford University and listed among the “Top 100,000 Scientists in the World” in the Global Scholars Database.

Abstract : Fractional order systems are dynamic systems described by non-integer order calculus equations, which compensate for the shortcomings of poor agreement between integer-order model theory and experimental results. Therefore, researchers have widely applied fractional calculus in various fields, including anomalous diffusion problems, constitutive relationships of viscoelastic materials, automatic control, mathematical biology, and seismic singularity analysis. Furthermore, based on various advanced control strategies and criteria for system controllability, the dynamic behavior of fractional systems has been thoroughly studied. However, in many practical problems, stochastic noises in complex environments are inevitable, which can more or less affect the dynamic characteristics of complex systems. To better understand and handle the behavior of complex systems and explore the design of strategies to deal with random disturbances, this paper applies fractional calculus theory, stochastic stability theory, and stochastic optimal control theory to establish the fractional system with stochastic noises, explore its qualitative characteristics, and design a reasonable control protocol to achieve relevant collaborative control and optimal control.

Professor Abdelfatah Charef

Title : New Simulations Perspectives of Variable Order Fractional Integrator I^m(t), Differentiator D^m(t) and PI^λ(t)D^μ(t) Controller

Session : To be scheduled
Université des Frères Mentouri – Constantine 1, Algeria

Bio : Abdelfatah Charef has received the Diplôme des Etudes Supérieures (DES) from the University of Constantine, Algeria, in 1984, the Master and Ph.D Degrees in Electrical Engineering from Drexel University, Philadelphia, Pennsylvania, USA, in 1987 and 1991, respectively. In September 1991, he has joined the Department of Electronics of the University of Constantine, Algeria, where he is currently Professor and member of the Signal Processing Laboratory. His current research interests are in the areas Fractional Order Operators and Systems, Fractional Order Control, Fractional Order Signal Processing and Applications of Fractional Operators and Systems in Biomedical Signal Processing.

Abstract : In the literature, most of the variable order fractional operator approximation models are impractical in on-line mode because it is necessary to recalculate all the involved models parameters with respect to variations of the time varying fractional. Therefore, there is a need for models that will reproduce their required characteristics with sufficient precision and accuracy and can easily operate in on-line mode without large memory for samples storage and without lot of computations.
This work presents, in a complete different way than the ones given in the literature, an original analog realizations and the numerical evaluations of the variable order fractional integrator I^m(t){●}, the variable order fractional differentiator D^m(t){●}, and the variable order fractional PI^λ(t)D^μ(t){●} controller using dynamical models derived from an adjustable order fractional integrator model based on Charef’s approximation using the first definition of the variable order fractional operators of Lorenzo and Hartley.
The numerical evaluations of the variable order fractional operators and controller of a given input are just the time responses of their respective proposed analog dynamical models. Illustrative examples are presented to confirm the usefulness and the efficiency of the proposed variable or-der fractional operators and controller analog realizations and numerical evaluations scheme. The obtained results are also compared to some works in the literature to show its accuracy.

Professor Mouffak Benchohra

Title : Degree of Nondensifiability and Applications
Session : To be scheduled
Department of mathematics at Djillali Liabes University, Sidi Bel Abbes, Algeria

Bio : Dr. Mouffak Benchohra (born 1964, Algeria) is a Full Professor at the department of mathematics of Djillali Liabes university of Sidi Bel Abbes since October 1994. Benchohra received the master’s degree in nonlinear analysis from Tlemcen university, Algeria 1994 and Ph.D. degree in mathematics from Djillali Liabes university, Sidi Bel Abbes, Algeria 1999. His research fields include fractional differential equations, evolution equations and inclusions, control theory and applications, etc. Benchohra has published more than 500 papers, and 11 monographs. He is a Highly Cited Researcher in Mathematics from Thompson Reuters (2014) and Clarivate Analytics (2017 and 2018), and word’s top 2% researcher from Stanford university (2020, 2021, 2022, 2023, 2024). Benchohra has also occupied the position of head of department of mathematics at Djillali Liabes University, Sidi Bel Abbes. He is in the Editorial Board of 12 international journals.

Abstract : In this talk we introduce the notion of degree of nondensifiability and its relationship with the measure of noncompactness. Some applications to the fixed point theory and the study of initial and boundary value problems for fractional differential equations are presented.

1. A. Bensalem, A. Salim, M. Benchohra, E. Karapinar, Fixed Point Theorems for Multi-valued Operators via the Degree of Nondensifiability and their Application to Integrodifferential Inclusions (Submitted).
2. A. Bensalem, I. Meradjah, A. Salim, M. Benchohra, and J. Nieto, Fixed Point Theorems Based on the Degree of Nondensifiability in $b$-Norm Spaces and Applications to Differential Problems, Fixed Point Theory.
3. K.E. Bensatal, A. Salim, M. Benchohra, Impulsive Integro-Differential Equations via Densifiability Techniques (Submitted)
4. N. Bettayed, A. Salim, J. E. Lazreg, M. Benchohra, On Tempered $\psi$-Caputo Fractional Differential Boundary value Problem via Densifiability Techniques, (Submitted).
5. C. Derbazi, Z. Baitiche, M. Benchohra, Y. Zhou, Boundary value problem for psi-Caputo fractional differential equations in Banach spaces via densifiability techniques, Mathematics, (2022), 10, 153.
6. G. Garcia and G. Mora, The degree of convex nondensifiability in Banach spaces, J. Convex Anal. Vol. 22 No. 3 (2015), 871-888.

Professor Carla Pinto

Title : Searching for Fractional Behavior in Epidemic Modeling: ‘Where’s Waldo?’
Session : To be scheduled
School of Engineering, Polytechnic of Porto, Portugal

Bio : Dr. Carla M. A. Pinto is a Coordinating (Associate) Professor at the School of Engineering, Polytechnic of Porto (P.PORTO), Portugal. She received her Ph.D. in Mathematics in January 2004. Her principal field of research is Mathematical Epidemiology, with broader interests in mathematical modeling and its applications to public health policy. Dr. Pinto has an extensive background in Nonlinear Dynamics and Bifurcation Theory. Her previous research encompasses the study of Central Pattern Generators for animal and robotic locomotion, coupled cell networks, and neuron-like systems, including the Hodgkin–Huxley, FitzHugh–Nagumo, and Morris–Lecar models. She currently serves as Editor of Chaos, Solitons and Fractals and Chaos X, and as Associate Editor for Computational and Applied Mathematics (Springer) and the International Journal of Dynamics and Control (Springer). In addition, she is a member of the editorial boards of several international journals, including Mathematical Methods in the Applied Sciences and the International Journal of Advanced Robotic Systems. She has also chaired and organized numerous international conferences in Applied Mathematics. Since 2017, Dr. Pinto has broadened her research to include Mathematics Education, with active participation in several Erasmus+ projects. She has served as Coordinator of the MATH-DIGGER and DrIVE-MATH projects and as Local Coordinator for multiple other Erasmus+ initiatives at P.PORTO.

Abstract : The Caputo fractional derivative has been extensively studied, with theoretical results and selected applications supporting its use. This talk raises foundational questions: Do Caputo fractional differential equations provide meaningful models? What memory effects are represented? How should these be interpreted in physical or biological contexts?
Within epidemiological and compartmental frameworks, the Riemann–Liouville derivative introduces non-Markovian features, linking past residence time in a compartment to current transition probabilities. Such mechanisms align with social or biological processes where long-term behavior reduces the likelihood of change, as in smoking cessation, addictions, or chronic diseases.
They also appear in scenarios where hazard rates decrease with time, such as survival after high-risk surgery. However, difficulties arise: not all epidemics exhibit memory; for instance, flu or COVID-19 recovery rates increase over time, contrary to a decaying hazard function. Moreover, initialization poses challenges: omitting pre-observation history can artificially inflate hazard rates at the model’s start. Example analyses suggest that integer-order models with time-varying parameters can capture decreasing hazards, potentially limiting the necessity of fractional terms.  While fractional formulations may slightly improve data fitting, the gain is often marginal compared with the added complexity. Thus, the justification for employing Caputo-type fractional models in epidemiology remains an open and nuanced question. 

Professor Horst Schulte

Title : Decentralized and Event-based Control of Distribution Grids by DVPP
Session : To be scheduled
School of Engineering, Polytechnic of Porto, Portugal

Bio : HORST SCHULTE (Member, IEEE) received the Diploma degree in electrical engineering from TU Berlin, the master’s degree in electrical engineering, focusing on automatic control and electrical power systems, and the Ph.D. degree in mechanical engineering from the University of Kassel, Germany. In 2005, he joined the Bosch Group, where he worked on research and development projects in modeling, optimization, and advanced control of actuators, power systems, and drive trains. Since November 2009, he has been a Full Professor at the University of Applied Sciences-HTW Berlin. His research interests include controller and observer design, active fault-tolerant control (FTC) system design with applications in wind energy systems and other renewab

Abstract : The keynote talk refers to advanced control strategies for managing distributed energy resources (DERs)—such as solar, wind, storage, and controllable loads—by aggregating them into virtual units (virtual power plants) that offer coordinated ancillary services to the distribution grid ¡and into the higher-level transmission grid. The main objective is to achieve grid resilience, flexibility, and efficient market participation via scalable, modular, and adaptive model-reference local power plant controller that operate with minimal centralized intervention and reduced communication overhead.
This is achieved through the Dynamic Virtual Power Plant (DVPP) concept, a paradigm that has attracted considerable research attention in recent years [1]. A DVPP dynamically aggregates heterogeneous DERs (e.g. wind power plants [2], solar photovoltaic power plants [3], storage, controllable loads) and coordinates their operation to provide grid-forming and ancillary services—such as frequency containment reserve, fast frequency control, and voltage support with the focus on short time scales (5 ms to 30 s).
The essential control-theoretic methods for decomposing a desired dynamic relationship between the measured frequency and voltage at selected network nodes and the distributed input power are presented. Both frequency-domain techniques for small-signal analysis around fixed operating points and time-domain formulations that capture the nonlinear local dynamics of generation units [4], as well as event-based global adaptation mechanisms [5], are employed.
The presentation includes simulation and experimental results and discusses how integrating fractional differentiation into both system modelling and controller design can substantially enhance the dynamic performance and robustness of local controllers.

[1] Marinescu, Bogdan., Gomis-Bellmunt, Oriol., DÅNorfler, Florian., Schulte, Horst and Sigrist, Lukas: Dynamic Virtual Power Plant: A New Concept for Grid Integration of Renewable Energy Sources, IEEE Access 2022

[2] Brunner, Johannes; Schulte, Horst: Takagi-Sugeno based Model Reference Control for Wind Turbine Systems in Frequency Containment Scenarios. In: at – Automatisierungstechnik 73, 10, 2025

[3] Schulte, Horst: Takagi-Sugeno Model Reference Control of Photovoltaic Power Plants to Provide Instantaneous Reserve. In: Proceedings of IEEE International Conference on Fuzzy Systems 2025 (FUZZ-IEEE). Reims, France: IEEE Xplore 2025

[4] Schulte, Horst; Resener, Mariana: Integration of Active Power-controlled Photovoltaic Energy Sources in Distribution Grids by Dynamic Virtual Power Plants. In: Proc. of 24th International Wind & Solar Integration Workshop (WIW2025). Berlin: 2025

[5] Schulte, Horst: Adaptive Model Reference Control for Multivariable Takagi- Sugeno Fuzzy Systems, In: Proceedings 34. Workshop Computational Intelligence. Karlsruhe, Germany: KIT Scientific Publishing 2025