scholarly journals Safety Behavior Analysis of a Delayed Control System

2021 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Time Delays ◽  
Large Range ◽  
Chaotic Behavior ◽  
System Behavior ◽  
Safety Behavior ◽  
Safety Issues ◽  
Delayed System ◽  
Complex Phenomena ◽  
Parameter Values ◽  
Range Of Values

Time delays in systems are becoming important phenomena now-a-days in regards to its safety issues. A continuous delayed system proposed by A. Uçar is considered for this work. Detailed works are concentrated on finding behavior of this system of continuous delayed system with respect to different system parameters. Self-written code is used to observe the behavior of the system. Self-written code gives flexibility to see behaviors of the system in more in depth. System behavior is observed for a very large range of parameters and comparison is made with others works. Results indicate that for a certain range of values of parameters the system show predictable behavior but after certain range of parameter values the system goes to unpredictable chaotic behavior. In addition, parametric relation is shown for same type of chaotic behavior. It is expected that this finding will increase understanding of complex phenomena involved in delayed dynamical system when safety is prime importance.

scholarly journals Multistability in Horizontal Platform System with and without Time Delays

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Karthikeyan Rajagopal ◽  
Prakash Duraisamy ◽  
Riessom Weldegiorgis ◽  
Anitha Karthikeyan
Keyword(s):  
Time Delay ◽  
Bifurcation Analysis ◽  
Time Delays ◽  
State Feedback ◽  
Chaotic Behavior ◽  
Constant Time Delay ◽  
Constant Time ◽  
System Behavior ◽  
Coexisting Attractors ◽  
Platform System

Chaotic behavior and bifurcation analysis of horizontal platform systems (HPS) have been investigated widely by many researchers. However, the multistable features of such systems have not been investigated, and hence we identified the multistable parameter and investigated the coexisting attractors of the HPS. To understand the effects of time delays on the nonautonomous and autonomous HPS, we introduced a constant time delay in the state feedback variable. Investigation of the bifurcation of the time delayed HPS with time delay and parameters reveals that the system behavior differs between the autonomous and nonautonomous HPS. To investigate the multistability existence in time delayed HPS, we plot the bifurcation of the autonomous HPS and show the multistability and coexisting attractors.

Oscillatory Dynamics of P53 Network With Time Delays

2018 ◽  
Vol 21 (6) ◽  
pp. 411-419 ◽  
Author(s):  
Conghua Wang ◽  
Fang Yan ◽  
Yuan Zhang ◽  
Haihong Liu ◽  
Linghai Zhang
Keyword(s):  
Hopf Bifurcation ◽  
Cell Fate ◽  
Time Delays ◽  
Sustained Oscillation ◽  
Multiple Time ◽  
Cell Fate Decisions ◽  
Oscillatory Dynamics ◽  
Main Components ◽  
Parameter Values ◽  
P53 Network

Aims and Objective: A large number of experimental evidences report that the oscillatory dynamics of p53 would regulate the cell fate decisions. Moreover, multiple time delays are ubiquitous in gene expression which have been demonstrated to lead to important consequences on dynamics of genetic networks. Although delay-driven sustained oscillation in p53-based networks is commonplace, the precise roles of such delays during the processes are not completely known. Method: Herein, an integrated model with five basic components and two time delays for the network is developed. Using such time delays as the bifurcation parameter, the existence of Hopf bifurcation is given by analyzing the relevant characteristic equations. Moreover, the effects of such time delays are studied and the expression levels of the main components of the system are compared when taking different parameters and time delays. Result and Conclusion: The above theoretical results indicated that the transcriptional and translational delays can induce oscillation by undergoing a super-critical Hopf bifurcation. More interestingly, the length of these delays can control the amplitude and period of the oscillation. Furthermore, a certain range of model parameter values is essential for oscillation. Finally, we illustrated the main results in detail through numerical simulations.

Discussion of Calculation of Power Function with Special Reference to Respiratory Metabolism in Fish

1969 ◽  
Vol 26 (10) ◽  
pp. 2643-2650 ◽  
Author(s):  
Norman R. Glass
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Power Function ◽  
Body Weight Data ◽  
Fitting Method ◽  
Wide Range ◽  
Curve Fitting Method ◽  
Parameter Values ◽  
Weight Data ◽  
Range Of Values

The rationale for employing a nonlinear iterative least-squares technique for fitting the well-known power function to oxygen consumption–body weight data is set forth. Twenty-six sets of routine or standard metabolism data from six authors were used to demonstrate the relative merits of two methods of calculating parameter values for the power function. The conclusion was reached that if accuracy in predicting oxygen consumption over a wide range of values of body weight is desired, an iterative curve fitting method may be superior to the much used technique of performing a linear regression on logarithmically transformed data.

Lg magnitudes and yield estimates for underground Novaya Zemlya nuclear explosions

1988 ◽  
Vol 78 (2) ◽  
pp. 873-884
Author(s):  
Otto W. Nuttli
Keyword(s):  
Large Range ◽  
Test Site ◽  
Nevada Test Site ◽  
P Values ◽  
Underground Nuclear Explosions ◽  
Nuclear Explosions ◽  
Novaya Zemlya ◽  
Short Period ◽  
Lg Wave ◽  
Range Of Values

Abstract Lg-wave amplitudes of 30 Novaya Zemlya underground nuclear explosions, as recorded by short-period seismographs in Denmark, Finland, Germany, Norway, Spitsbergen, and Sweden, are used to determine mb(Lg) values. Assuming that the mb(Lg) versus explosion yield relation derived from Nevada Test Site data applies to all continental areas, the yields of the explosions are estimated. They cover a large range of values, from 2.5 to 4900 kt. The largest explosion since April 1976 had an estimated yield of 145 kt. The mb(Lg) values, when subtracted from the mb(P) values, can be used to estimate the mb(P) bias between two test sites. In this way, the mb(P) bias between Novaya Zemlya and the Nevada Test Site is estimated to be 0.20 magnitude units.

Basic Definitions

2010 ◽  
pp. 17-50
Author(s):  
Eleonora Bilotta ◽  
Pietro Pantano
Keyword(s):  
Cellular Automata ◽  
Dynamic Systems ◽  
Chaotic Behavior ◽  
Crucial Importance ◽  
Von Neumann ◽  
3 Dimensional ◽  
Straight Line ◽  
Discrete Dynamic Systems ◽  
Complex Phenomena ◽  
Emergent Behaviors

Cellular Automata (CAs) are discrete dynamic systems that exhibit chaotic behavior and self-organization and lend themselves to description in rigorous mathematical terms. The main aim of this chapter is to introduce CAs from a formal perspective. Ever since the work of von Neumann (1966), von Neumann & Burks (1970), Toffoli & Norman (1987), Wolfram (1983; 1984), and Langton (1984; 1986; 1990), specialists have recognized CAs as a model of crucial importance for complexity studies. Like other models used in the investigation of complex phenomena (Chua & Yang, 1988; Chua, 1998), a CA consists of a number of elementary components, whose interactions determine its dynamics. In this and the following chapters, we will sometimes refer to these elementary components as cells, sometimes as sites. The cells of a CA can be positioned along a straight line or on a 2 or 3-dimensional grid, creating 1-D, 2-D and 3-D CAs. Automata consisting of cells whose only possible states are 0 or 1, are Boolean Automata; automata whose cells can assume more than 2 states are multi-state CAs. In both cases, the CA contains “elementary particles” whose dynamics are governed by simple rules. These rules determine sometimes unpredictable, emergent behaviors, ranging from the simple, through the complex to the chaotic.

scholarly journals MHD instabilities at the disk-magnetosphere boundary: 3D simulations

2007 ◽  
Vol 3 (S243) ◽  
pp. 291-298
Author(s):  
Akshay K. Kulkarni ◽  
Marina M. Romanova
Keyword(s):  
Accretion Disk ◽  
Equatorial Plane ◽  
Polar Region ◽  
Large Range ◽  
3D Simulations ◽  
Mhd Instabilities ◽  
Parameter Values

AbstractWe present results of 3D simulations of MHD instabilities at the accretion disk-magnetosphere boundary. The instability is Rayleigh-Taylor, and develops for a large range of parameter values. It manifests itself in the form of tall, thin tongues of plasma that reach the star by penetrating through the magnetosphere in the equatorial plane. The tongues rotate around the star in the equatorial plane, and their shape and number changes with time on inner-disk dynamical timescales. In contrast with funnel flows, which deposit matter mainly in the polar region, the tongues deposit matter much closer to the stellar equator.

scholarly journals Estimating the state of a geophysical system with sparse observations: time delay methods to achieve accurate initial states for prediction

2017 ◽  
Vol 24 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Zhe An ◽  
Daniel Rey ◽  
Jingxin Ye ◽  
Henry D. I. Abarbanel
Keyword(s):  
Time Delays ◽  
Time Series Data ◽  
Chaotic Behavior ◽  
Weather Prediction ◽  
Series Data ◽  
State Variables ◽  
Nonlinear Shallow Water Equations ◽  
Delayed Measurements ◽  
Lagrangian Drifter ◽  
Geophysical System

Abstract. The problem of forecasting the behavior of a complex dynamical system through analysis of observational time-series data becomes difficult when the system expresses chaotic behavior and the measurements are sparse, in both space and/or time. Despite the fact that this situation is quite typical across many fields, including numerical weather prediction, the issue of whether the available observations are "sufficient" for generating successful forecasts is still not well understood. An analysis by Whartenby et al. (2013) found that in the context of the nonlinear shallow water equations on a β plane, standard nudging techniques require observing approximately 70 % of the full set of state variables. Here we examine the same system using a method introduced by Rey et al. (2014a), which generalizes standard nudging methods to utilize time delayed measurements. We show that in certain circumstances, it provides a sizable reduction in the number of observations required to construct accurate estimates and high-quality predictions. In particular, we find that this estimate of 70 % can be reduced to about 33 % using time delays, and even further if Lagrangian drifter locations are also used as measurements.

scholarly journals O, H and C isotopic systematics of Icelandic groundwater

2019 ◽  
Vol 98 ◽  
pp. 07031
Author(s):  
Arny E. Sveinbjörnsdóttir ◽  
Andri Stefánsson ◽  
Jan Heinemeier
Keyword(s):  
Isotopic Composition ◽  
Carbon Isotopes ◽  
Upper Mantle ◽  
Lower Crust ◽  
Natural Waters ◽  
Large Range ◽  
Carbon Sources ◽  
Water Isotopes ◽  
Stable Water Isotopes ◽  
Range Of Values

Stable water isotopes of oxygen and hydrogen have been studied in Icelandic natural waters since 1960 for hydrological and geothermal research. All the waters are of meteoric and seawater origin. The measured range in δD and δ18O is large -131 to +3.3‰ and -20.8 to +2.3‰ respectively. Some of the waters are more depleted than any present-day precipitation suggesting a pre-Holocene component in the groundwater. Carbon isotopes of streams, rivers, soil and groundwater have been studied since 1990 in order to evaluate the carbon sources and reactions that possibly influence the carbon systematics of the water. Results show large range of values, for δ13CDIC -27.4 to +4.5‰ and for 14CDIC +0.6 to +118 pMC. Apart from atmospheric, organic and rock leaching, input of gas at depth with similar isotopic composition as the pre-erupted melt of the upper mantle and lower crust beneath Iceland have been identified as sources for carbon in the deeper groundwater.

STABILITY AND RESPONSIVENESS OF THE CARDIOVASCULAR SYSTEM UNDER A PHYSIOLOGICALLY INSPIRED BAROREFLEX MODEL

2015 ◽  
Vol 15 (02) ◽  
pp. 1540014 ◽  
Author(s):  
ANDREA DUGGENTO ◽  
NICOLA TOSCHI ◽  
ANTONIO CANICHELLA ◽  
ITALO VANNUCCI ◽  
MARIA GUERRISI
Keyword(s):  
Control Mechanism ◽  
Chaotic Behavior ◽  
Compartment Model ◽  
Whole Body ◽  
Total Blood Volume ◽  
Total Blood ◽  
Return Maps ◽  
Model Flexibility ◽  
Simulation Parameters ◽  
Parameter Values

We investigate the Seidel–Herzel model of the human baroreflex feedback control mechanism in terms of parameter choices and its ability to mimic heart rate physiology. We show that this model has the potential to be re-parameterized to better mimic features commonly observed in human physiology. We investigate the modification of the RR return maps as a function of parameter values and show that the model exhibits chaotic behavior. Extensive simulations are performed to establish which parameters mostly contribute to model flexibility in terms of observable output, and critical considerations are cast about potential pitfalls in model re-parameterization to mimic health and pathological behaviors. The Seidel–Herzel model is then merged with a detailed 21-compartment model for the vascular bed in order to examine sensitivity of RR dynamics to whole body simulation parameters. Pathological situations are simulated by altering total blood volume, ventricular compliances and baroreflex gains. The RR solutions show bifurcation diagrams typical of chaotic behavior, where the extension of the chaotic regions is in general smaller in simulated pathological states when compared to baseline (healthy) situations. We speculate that, despite the limits of the model and the limitations of the physiological parameterization, a loss of chaotic behavior correlates with the presence of disease-related aberrations.

Inviscid quasi-geostrophic flow over topography: testing statistical mechanical theory

1996 ◽  
Vol 309 ◽  
pp. 85-91 ◽  
Author(s):  
William J. Merryfield ◽  
Greg Holloway
Keyword(s):  
Numerical Simulations ◽  
Large Range ◽  
Initial Conditions ◽  
Steady Flows ◽  
Mechanical Theory ◽  
Geostrophic Flow ◽  
Mechanical Description ◽  
Flow Over Topography ◽  
Statistical Mechanical ◽  
Parameter Values

Numerical simulations are employed in a detailed test of the statistical mechanical description of topographic turbulence. Predictions of steady flows correlated with topography are given particular attention. Agreement between numerical and statistical mechanical results is demonstrated for a large range of parameter values, and over an ensemble of random choices of topography and initial conditions.

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