Nonlinear systems

This paper applies the homotopy analysis method to study nonlinear free vibrations. The paper has used the homotopy analysis method to find analytical solutions of a nonlinear two-degree-of-freedom system. Analytical results have found the natural oscillation frequencies, the displacement formula of the system are approximately calculated at the 10th order.

9p viengfa 28-10-2024 2 0   Download

In this article, we establish a Digital Radio over Fiber (DRoF) information system with two wireless channels utilizing two advanced phase modulation techniques, namely Differential Phase Shift Keying (DPSK), for the CRAN connection and investigate parameters related to nonlinearity such as refractive index n2.

6p viengfa 28-10-2024 2 2   Download

In this paper, we propose a wavelet type-2 fuzzy brain imitated controller (WT2FBIC) for nonlinear robotic systems. The suggested method combines a wavelet type-2 fuzzy system (WT2FS) and a brain imitated controller (BIC) to improve learning efficiency.

11p viling 11-10-2024 1 1   Download

This paper presents an improved method of direct torque control (DTC) for three–phase asynchronous motors with squirrel cage rotors. The improved method of DTC uses three sliding mode controllers to control torque and flux independently.

13p viling 11-10-2024 1 0   Download

This paper aims to propose a design of a type-2 fuzzy cerebellar model articulation controller for uncertain nonlinear systems, which achieves high stability and accuracy for controlling magnetic levitation systems. The proposed controller is a combination of a type 2 fuzzy logic system and a cerebellar model articulation controller.

10p viling 11-10-2024 4 1   Download

Layered structures are widely used in construction, such as pavement structures consisting of multiple layers of different materials or interfaces between bricks and mortar in masonry structures, etc. In analyzing such structures, understanding the properties of the interface between two layers of materials is essential.

15p vibecca 01-10-2024 2 1   Download

Seismic analysis of soil-structure interaction (SSI) is a challenge due to the nonlinearities of soil-foundation interaction (SFI). The reliability of the design and the analysis results will suffer if SSI is ignored. In this paper, a two-step method based on the superposition theorem is used to perform a seismic analysis of a soil-foundation-tank-liquid system (soil-liquid tank system).

13p vibecca 01-10-2024 1 1   Download

The inverted pendulum on a cart is a challenging and widely studied control problem in the fields of control systems and robotics. To address the need for more effective control strategies, this article presents a novel approach that combines the strengths of two powerful control techniques: Linear-Quadratic Regulator (LQR) and Takagi-Sugeno (T-S) fuzzy control.

15p viyoko 01-10-2024 3 1   Download

This paper introduces the shear lag effect, which is the phenomenon of nonlinear distribution in axial stress among the tube columns due to the difference in shear deformations of the structural system when subjected to lateral loads.

8p viyoko 24-09-2024 1 1   Download

In this article, a Python-programmed advanced design paradigm is firstly introduced to topology and size optimization of the X-bracing system of nonlinear inelastic space steel frames. For that purpose, an advanced analysis method considering both geometric and material nonlinearities is utilized as an effective finite element analysis (FEA) solver.

13p vifaye 20-09-2024 2 1   Download

The purpose of the field-oriented control (FOC) is therefore to create a tool that allows the decoupling control of the flux and torque-producing current components from the three-phase AC currents flowing in the coil. The FOC drive system is a system based on the principle of decoupling the above power components thanks to the stator current feedback control (the innermost circuit of the drive system). The FOC-type control method belongs to the class of vector control methods for electrical machines.

22p dianmotminh02 03-05-2024 6 2   Download

This paper presents a method for establishing the exact receptance function of a tapered axially functionally graded (AFG) beam with nonlinear ratios of properties using the Adomian method. In current papers, the Adomian method was applied for linearly tapered beams where the geometric series was used conveniently.

22p dianmotminh02 03-05-2024 5 2   Download

Magnetic bearing systems have received much attention in the research community for the past decades. Its inherent nonlinearity and open-loop instability present challenges for controller design. This thesis investigates and designs model predictive control (MPC) systems for an experimental Active Magnetic Bearing (AMB) laboratory system. A host-target development environment of real-time control system with hardware in the loop (HIL) is used for implementation of the predictive control systems. In this thesis, both continuous and discrete time model predictive controllers are studied.

172p runthenight05 01-03-2023 9 3   Download

In the course of current research the procedure of obtaining of the piecewise linear vibration systems time and frequency responses have been developed. The method is partly analytical and partly numerical and is based on combining of linear solutions of different sections in a cycle of motion. In a row with the method of obtaining of the exact steady state time and frequency response, also it is provided sensitivity analysis of the vibration isolator.

86p runthenight07 01-03-2023 10 3   Download

Model Predictive Control (MPC) refers to a class of algorithms that optimize the future behavior of the plant subject to operational constraints. The merits of the class algorithms include its ability to handle imposed hard constraints on the system and perform on-line optimization. This thesis investigates design and implementation of continuous time model predictive control using Laguerre polynomials and extends the design approaches proposed in to include intermittent predictive control, as well as to include the case of the nonlinear predictive control.

162p runthenight07 01-03-2023 9 4   Download

This paper considers the problem of a low-velocity normal impact of a rigid cone-shaped upon a viscoelastic plate. The contact force is defined by the modified Hertz's contact law. Approximate solutions of the system of nonlinear integro-differential equations for the contact force and local indentation have been obtained.

7p meyerowitz 25-12-2021 11 1   Download

Research aims: This thesis is concerned with the stability of some classes of nonlinear time-delay systems in neural networks. Investigating the problem of stability of non-autonomous neural networks with heterogeneous time-varying delays in the effect of destablizing impulses. Stabilizing Hopfiled neural networks with proposition delays subject to stabilizing and destablizing impulsive effects simultaneously.

27p tunelove 10-06-2021 22 4   Download

The studied object is the Kerr nonlinear optical systems and optical resonator tworing systems linear coupling with the presence of linear gain and nonlinear loss.

26p prisonbreak123 21-05-2021 12 4   Download

Research purpose: to build an analytical model representing the cross Kerr nonlinear coefficient of a four-energy quantum system in the inverse Y configuration in the presence of the Doppler effect. Apply the analytical results to the case of 87Rb at room temperature. Studying the ability to control and enhance the cross Kerr nonlinearity according to the parameters of the associated laser field and the temperature of the environment.

26p prisonbreak123 21-05-2021 17 4   Download

In recent years, optical orthogonal frequency division multiplexing (OOFDM) has emerged as a dominant research and development area in the field of high-speed optical communications. OFDM is a potential candidate as the most promising next-generation optical networks such as passive optical networks and optical transport networks, due to their simple configuration based on low cost, high speed data rates, high spectral efficiency, high quality of service and robustness against narrow band interference, frequency selective fading, and chromatic dispersion.

99p nguathienthan12 18-05-2021 21 7   Download