scholarly journals A New Three-Oscillator Model for the Heart System in the Case of Time Delay and Designing Appropriate Controller for Its Synchronization

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Siroos Nazari ◽  
Aghileh Heydari ◽  
Mahboobeh Tavakoli ◽  
Javad Khaligh
Keyword(s):  
Time Delay ◽  
Delay Time ◽  
The State ◽  
Time Factor ◽  
Oscillator Model ◽  
Oscillator System ◽  
Simulation Results

If the SA and AV oscillators are not synchronized, it may arise some kinds of blocking arrhythmias in the system of heart. In this paper, in order to examine the heart system more precisely, we apply the three-oscillator model of the heart system, and to prevent arrhythmias, perform the following steps. Firstly, we add a voltage with rang a1 and ω frequency to SA node. Then, we use delay time factor in oscillators and finally the appropriate control is designed. In this paper, we have explained how simulating and curing these arrhythmias are possible by designing a three-oscillator system for heart in the state of delay and without delay and by applying an appropriate control. In the end, we present the simulation results.

scholarly journals Time delay effect in a three coupled oscillator system of the physarum plasmodium

2000 ◽  
Vol 40 (supplement) ◽  
pp. S100
Author(s):  
A. Takamatsu ◽  
T. Fujii ◽  
I. Endo
Keyword(s):  
Time Delay ◽  
Delay Effect ◽  
Coupled Oscillator ◽  
Oscillator System ◽  
Time Delay Effect

Comprehensive Analysis for Influence of Controllable Damper Time Delay on Semi-Active Suspension Control Strategies

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Yechen Qin ◽  
Feng Zhao ◽  
Zhenfeng Wang ◽  
Liang Gu ◽  
Mingming Dong
Keyword(s):  
Time Delay ◽  
Dynamic Characteristics ◽  
Ride Comfort ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Active Suspension ◽  
Test System ◽  
Suspension Control ◽  
Simulation Results

This paper presents a comprehensive comparison and analysis for the effect of time delay on the five most representative semi-active suspension control strategies, and refers to four unsolved problems related to semi-active suspension performance and delay mechanism that existed. Dynamic characteristics of a commercially available continuous damping control (CDC) damper were first studied, and a material test system (MTS) load frame was used to depict the velocity-force map for a CDC damper. Both inverse and boundary models were developed to determine dynamic characteristics of the damper. In addition, in order for an improper damper delay of the form t+τ to be corrected, a delay mechanism of controllable damper was discussed in detail. Numerical simulation for five control strategies, i.e., modified skyhook control SC, hybrid control (HC), COC, model reference sliding mode control (MRSMC), and integrated error neuro control (IENC), with three different time delays: 5 ms, 10 ms, and 15 ms was performed. Simulation results displayed that by changing control weights/variables, performance of all five control strategies varied from being ride comfort oriented to being road handling oriented. Furthermore, increase in delay time resulted in deterioration of both ride comfort and road handling. Specifically, ride comfort was affected more than road handling. The answers to all four questions were finally provided according to simulation results.

scholarly journals Spatiotemporal Patterns Formed by a Discrete Nutrient-Phytoplankton Model with Time Delay

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Feifan Zhang ◽  
Wenjiao Zhou ◽  
Lei Yao ◽  
Xuanwen Wu ◽  
Huayong Zhang
Keyword(s):  
Steady State ◽  
Time Delay ◽  
Numerical Simulations ◽  
Functional Response ◽  
Bifurcation Analysis ◽  
Discrete Model ◽  
Continuous Model ◽  
Spatiotemporal Patterns ◽  
Homogeneous Steady State ◽  
Simulation Results

In this research, a continuous nutrient-phytoplankton model with time delay and Michaelis–Menten functional response is discretized to a spatiotemporal discrete model. Around the homogeneous steady state of the discrete model, Neimark–Sacker bifurcation and Turing bifurcation analysis are investigated. Based on the bifurcation analysis, numerical simulations are carried out on the formation of spatiotemporal patterns. Simulation results show that the diffusion of phytoplankton and nutrients can induce the formation of Turing-like patterns, while time delay can also induce the formation of cloud-like pattern by Neimark–Sacker bifurcation. Compared with the results generated by the continuous model, more types of patterns are obtained and are compared with real observed patterns.

scholarly journals New delay-dependent observer-based control for uncertain stochastic time-delay systems

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Xiu-feng Miao ◽  
Long-suo Li
Keyword(s):  
Time Delay ◽  
The State ◽  
Delay Systems ◽  
Linear Matrix ◽  
Time Delay Systems ◽  
Parameter Uncertainties ◽  
Noise Disturbances ◽  
System States ◽  
Delay Dependent ◽  
Stochastic Time

AbstractThis paper considers the problem of estimating the state vector of uncertain stochastic time-delay systems, while the system states are unmeasured. The system under study involves parameter uncertainties, noise disturbances and time delay, and they are dependent on the state. Based on the Lyapunov–Krasovskii functional approach, we present a delay-dependent condition for the existence of a state observer in terms of a linear matrix inequality. A numerical example is exploited to show the validity of the results obtained.

Simulation on the Regulating Characteristics of the Pulse Modulation Hydraulic Hammer

2011 ◽  
Vol 422 ◽  
pp. 176-183
Author(s):  
Gang Wang ◽  
Yu Wan Cen
Keyword(s):  
Time Delay ◽  
Simulation Model ◽  
Impact Energy ◽  
High Speed ◽  
Impact Frequency ◽  
Pulse Modulation ◽  
Motion Equations ◽  
Hydraulic Hammer ◽  
Working Frequency ◽  
Simulation Results

To improve the regulating characteristics of impact energy, simplify structure of hydraulic hammer, a new pulse modulation hydraulic hammer is presented in the paper which can help regulate its impact frequency easily. The motion equations of the hydraulic hammer are established, its simulation model is obtained and the dynamic simulation is carried out on AMESim. The dynamics of high-speed ON/OFF valve is taken into account in the simulation model. The tendency of simulation results conforms to experimental results; it shows that the pulse modulation hydraulic hammer is feasible, and the hydraulic hammer model is reasonable. The time delay in high working frequency is also analyzed.

Measurement of the Pulverized Coal Concentration by Measuring the Time Delay of Ultrasonic with Digital Correlation Method

2013 ◽  
Vol 333-335 ◽  
pp. 359-364
Author(s):  
Ke Wang
Keyword(s):  
Time Delay ◽  
Power Plant ◽  
Correlation Method ◽  
The State ◽  
Pulverized Coal ◽  
Measuring System ◽  
Digital Correlation ◽  
Coal Boiler ◽  
Key Parameter

The pulverized coal concentration in blast pipe in front of firebox is one key parameter in coal boiler used in a power plant; it will affect the state of burning in firebox. This paper proposes a new digital correlation method to measure the time delay of ultrasonic for measuring the pulverized coal concentration. The principle of measurement is discussed in detail and the measuring system is designed.

scholarly journals Experience Rating of ARIMA Processes by the Kalman Filter

1986 ◽  
Vol 16 (1) ◽  
pp. 19-31 ◽  
Author(s):  
Jukka Rantala
Keyword(s):  
Kalman Filter ◽  
Time Delay ◽  
State Space ◽  
Theoretical Approach ◽  
Space Form ◽  
The State ◽  
Experience Rating ◽  
Filter Technique ◽  
Main Emphasis ◽  
Arima Processes

AbstractThis paper deals with experience rating of claims processes of ARIMA structures. By experience rating we mean that future premiums should be only a function of past values of the claims process. The main emphasis is on demonstrating the usefulness of the control-theoretical approach in the search for optimal rating rules. Optimality is here defined to mean as smooth a flow of premiums as possible when the variation in the accumulated profit is restricted to a certain amount. First it is shown how the underlying model in its simplest form can be transformed into the state-space form. Then the Kalman filter technique is used to find the optimal rules. Also a time delay in information is taken into account. The optimal rules are illustrated by examples.

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