Results 81 to 90 of about 3,260 (185)
A Data‐Driven Closed‐Loop Control Approach to Drive Neural State Transitions for Mechanistic Insight
Human Brain Mapping, Volume 47, Issue 11, 01 August 2026.The study introduces a data‐driven framework combining dynamical systems reconstruction and closed‐loop control to analyze brain‐state transitions in remitted depression. Using fMRI data, we show that these individuals more easily enter but struggle to exit sad mood states, revealing altered connectivity and potential neuromodulation targets for ...
Niklas Emonds +8 more
wiley +1 more source
New 4-D Hyperchaotic System Derived from the Rikitake 3-D System:Properties and Application
NTU Journal of Pure SciencesA novel 4D hyperchaotic system with two positive Lyapunov exponents is created from a Rikitake 3D system using a feedback control strategy. Several dynamical properties are investigated both theoretically and numerically, including phase, equilibrium ...
Anmar Mohammed Shaker +1 more
doaj +1 more source
Quantifying Chaos by Various Computational Methods. Part 1: Simple Systems
Entropy, 2018 The aim of the paper was to analyze the given nonlinear problem by different methods of computation of the Lyapunov exponents (Wolf method, Rosenstein method, Kantz method, the method based on the modification of a neural network, and the synchronization
Jan Awrejcewicz +5 more
doaj +1 more source
A New Hyperchaotic 4D-FDHNN System with Four Positive Lyapunov Exponents and Its Application in Image Encryption. [PDF]
Entropy (Basel), 2022 Liu Z, Li J, Di X.
europepmc +1 more source
Mathematical Analysis and Simulations of a Cancer Model With Interleukins and Delayed Immunotherapy
Mathematical Methods in the Applied Sciences, Volume 49, Issue 12, Page 13946-13970, August 2026.ABSTRACT A new system of delayed differential equations for tumor‐immune system interactions is proposed and studied. The system describes the interactions between tumor cells and the immune system at the most aggressive phase of cancer, where tumor cells have developed mechanisms from earlier stages to evade immune responses.
Laid Boudjellal +2 more
wiley +1 more source
International Journal of Robust and Nonlinear Control, Volume 36, Issue 12, Page 6047-6067, August 2026.ABSTRACT In this work, a new event‐triggered adaptive first‐order sliding mode control method is proposed for nonlinear systems with constant time delays, modeled by interval type‐2 Takagi–Sugeno (T–S) fuzzy systems. To handle matched disturbances with unknown upper bounds, a non‐overestimating adaptation strategy for the control coefficient is ...
Rodrigo Possidonio Noronha +1 more
wiley +1 more source
Numerical Approximation of LYAPUNOV-Exponents for Quasiperiodic Motions
MATEC Web of Conferences, 2018 This paper proposes an approach to approximate the LYAPUNOV -spectrum of quasiperiodic flows on isolated invariant manifolds numerically. Once the invariant manifold has been determined, integrations over the infinite, one dimensional time interval – as ...
Fiedler Robert, Hetzler Hartmut
doaj +1 more source
Lyapunov Characteristic Exponents are Nonnegative [PDF]
Proceedings of the American Mathematical Society, 1993 We prove that, for an arbitrary rational map f f on the Riemann sphere and an arbitrary probability invariant measure on ...
openaire +1 more source
Miners' Reward Elasticity and Stability of Competing Proof‐of‐Work Cryptocurrencies
International Economic Review, Volume 67, Issue 3, Page 957-976, August 2026.ABSTRACT Proof‐of‐Work cryptocurrencies employ miners to sustain the system through algorithmic reward adjustments. We develop a stochastic model of the multicurrency mining and identify conditions for stable transaction speeds. Bitcoin's algorithm requires hash supply elasticity <$<$1 for stability, while ASERT remains stable for any elasticity and ...
Kohei Kawaguchi +2 more
wiley +1 more source
Hyperchaos Numerical Simulation and Control in a 4D Hyperchaotic System
Discrete Dynamics in Nature and Society, 2013 A hyperchaotic system is introduced, and the complex dynamical behaviors of such system are investigated by means of numerical simulations. The bifurcation diagrams, Lyapunov exponents, hyperchaotic attractors, the power spectrums, and time charts are ...
Junhai Ma, Yujing Yang
doaj +1 more source