Noise, Synchronization and Coherence in Chaotic Oscillators

2003 ◽  
Vol 17 (22n24) ◽  
pp. 4023-4044 ◽  
Author(s):  
Jürgen Kurths ◽  
Changsong Zhou
Keyword(s):  
Phase Space ◽  
The Other ◽  
Collective Oscillation ◽  
Time Intervals ◽  
Chaotic Oscillators ◽  
Phase Dynamics ◽  
Homoclinic Chaos ◽  
Coherent Phase ◽  
Spike Sequences ◽  
Coherent Behavior

We study effects of noise in two types of chaotic oscillators. The first one, represented by the Rössler system, has very coherent phase dynamics while the amplitude fluctuates strongly. The other type, homoclinic chaos characterized by chaotic spiking behavior, has regular orbits in the phase space while the interspike time intervals vary enormously. We demonstrate that in both classes of systems, noise may play a constructive role to enhance synchronization and generate the most coherent behavior in the collective oscillation of coupled phase coherent oscillators or in the spike sequences of homoclinic chaos.

scholarly journals SYNCHRONIZATION AS A PROCESS OF SHARING AND TRANSFERRING INFORMATION

2012 ◽  
Vol 22 (11) ◽  
pp. 1250261 ◽  
Author(s):  
ERIK M. BOLLT
Keyword(s):  
Symbolic Dynamics ◽  
Slow Manifold ◽  
Transfer Entropy ◽  
The Other ◽  
Chaotic Oscillators ◽  
Smale Horseshoe ◽  
Global System ◽  
Identity Function ◽  
Transfer Operators ◽  
First Time

Synchronization of chaotic oscillators has become well characterized by errors which shrink relative to a synchronization manifold. This manifold is the identity function in the case of identical systems, or some other slow manifold in the case of generalized synchronizaton in the case of nonidentical components. On the other hand, since many decades beginning with the Smale horseshoe, chaotic oscillators can be well understood in terms of symbolic dynamics as information producing processes. We study here the synchronization of a pair of chaotic oscillators as a process for sharing information bearing bits transferred between each other, by measuring the transfer entropy tracked as the global system transitions to the synchronization state. Further, we present for the first time the notion of transfer entropy in the measure theoretic setting of transfer operators.

scholarly journals Aferição do pH de diferentes agentes clareadores indicados para o clareamento intracoronário

2018 ◽  
Author(s):  
João Felipe Besegato ◽  
Gabriela Dos Santos Ribeiro Rocha ◽  
Marlene De Sousa Amorim ◽  
Fabio Martins Salomão ◽  
Daniel Poletto ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Statistical Analysis ◽  
Multiple Comparisons ◽  
The Other ◽  
Sodium Perborate ◽  
Distilled Water ◽  
Friedman Test ◽  
Time Intervals ◽  
Ph Values ◽  
Evaluation Time

Objective: to measure pH values of bleaching agents that are indicated to intracoronal bleaching technique in different time intervals. Methods: Each group (G) received five samples (n=5): G1 – distilled water (AD); G2 – hydrogen peroxide (H2O2) 30%; G3 – sodium perborate (PbS) + AD; G4 – PbS + H2O2 30%; G5 – sodium percarbonate (PcS) + AD; and G6 – PcS + H2O2 30%. pH values were stated using a digital pHmeter, in different time intervals: immediately after handling (T0), 24 hours (T1) and 168 hours after handling (T2). The results were submitted to statistical analysis through Kruskal-Wallis and Mann Whitney tests, in this order, allowing multiple comparisons among the groups. To verify the effect of time in each group, Friedman test was applied. Results: In the evaluation of the effect of time in each group, it was observed that G2 presented acid behavior, while the other groups exhibited values close to neutrality or alkaline. Conclusions: H2O2 30% was the only agent that showed acidic behavior in every evaluation time. Meanwhile, PcS + H2O had the highest pH values.

Epitopic characterisation of Turkish bovine viral diarrhoea virus (bvdv) isolates using monoclonal antibodies

2003 ◽  
Vol 51 (2) ◽  
pp. 237-244 ◽  
Author(s):  
K. Yeşilbağ ◽  
I. Burgu
Keyword(s):  
Monoclonal Antibodies ◽  
Plaque Assay ◽  
Bovine Viral Diarrhoea Virus ◽  
The Other ◽  
Bovine Viral Diarrhoea ◽  
Time Intervals ◽  
Field Isolates ◽  
Epitope Analysis ◽  
Diarrhoea Virus ◽  
Limiting Dilution

In this study, 15 bovine viral diarrhoea viruses (BVDV) isolated from the field in Turkey were characterised for their biotype, cloned and eventually analysed for their epitopic composition in terms of glycoprotein E2. Immunoplaque assay, plaque assay, limiting dilution and streptavidin-biotin-peroxidase techniques were used for biotype characterisation, cloning of cytopathic (cp) and noncytopathic (ncp) biotypes and epitope analysis, respectively. While 14 out of 15 BVDV isolates were distinguished as ncp biotype, 1 isolate was found to be containing both biotypes (cp + ncp). According to the reactivity patterns of isolates with 15 monoclonal antibodies, 4 different antigenic groups could be formed. There were no antigenic differences between the isolates derived from the same animal with various time intervals. On the other hand, biotype clones isolated from the same animal exhibited difference in one epitope. This is the first study describing antigenic characterisation of BVDV field isolates in Turkey.

Stratigraphic biases in the analysis of taxonomic survivorship

Paleobiology ◽  
1975 ◽  
Vol 1 (4) ◽  
pp. 343-355 ◽  
Author(s):  
J. John Sepkoski
Keyword(s):  
Simple Model ◽  
Lognormal Distribution ◽  
Fossil Record ◽  
The Other ◽  
Time Intervals ◽  
Survivorship Analysis ◽  
Other Hand ◽  
Incomplete Sampling ◽  
Biologic Factors

Taxonomic survivorship curves may reflect stratigraphic as well as biologic factors. The approximately lognormal distribution of lengths of Phanerozoic time intervals produces an error in the estimation of taxonomic durations that is also lognormally distributed. As demonstrated by several simulated examples, this error may cause concave taxonomic survivorship curves to appear linear, especially if the maximum durations involved are relatively short. The error of estimation also makes highly concave taxonomic survivorship curves virtually unrecognizable. Incomplete sampling of the fossil record, on the other hand, may not be a serious problem in survivorship analysis. Simulated paleontological sampling employing a simple model suggests that survivorship curves tend to retain their original shapes even when as few as 20% of the taxa have been discovered. However, concave taxonomic survivorship curves tend to lose their concavity as efficiency of sampling declines.

scholarly journals Assessing Quantitative Criteria for Characterization of Quality Categories for Grafted Watermelon Seedlings

Horticulturae ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Filippos Bantis ◽  
Athanasios Koukounaras ◽  
Anastasios Siomos ◽  
Georgios Menexes ◽  
Christodoulos Dangitsis ◽  
...  
Keyword(s):  
Dry Weight ◽  
The Other ◽  
Time Intervals ◽  
Important Species ◽  
Shoot Dry Weight ◽  
Shoot Ratio ◽  
Quality Categories ◽  
Critical Limits ◽  
Experienced Personnel

Vegetable grafting is a practice employed worldwide since it helps prevent biotic and abiotic disorders, and watermelon is one of the most important species grafted. The objective of this study was to set critical limits for the characterization of quality categories for grafted watermelon seedlings. Specifically, watermelon (scion) seedlings were grafted onto squash (rootstock) seedlings, moved into a healing chamber for 7 days, and then transferred into a greenhouse for seven more days. At 7 and 14 days after grafting, experienced personnel assessed grafted seedling quality by categorizing them. The categories derived were Optimum and Acceptable for both time intervals, plus Not acceptable at 14 days after grafting. Optimum seedlings showed greater leaf area, and shoot and root fresh and dry weights at both time intervals. Moreover, they had greater stem diameter, root-to-shoot ratio, shoot dry weight-to-length ratio and Dickson’s quality index compared to the other category at 14 days after grafting. Therefore, Optimum seedlings would likely develop into marketable plants of high quality, with better establishment in the field. Not acceptable seedlings showed considerably inferior development, while Acceptable seedlings were between the other categories, but were still marketable.

scholarly journals THE SKIN REACTIONS PRODUCED BY ALTERNATIONS OF HEAT AND X-RAY AT VARIOUS TIME INTERVALS

1931 ◽  
Vol 53 (3) ◽  
pp. 405-411 ◽  
Author(s):  
James A. Hawkins
Keyword(s):  
Guinea Pig ◽  
The Other ◽  
X Rays ◽  
Time Intervals ◽  
Skin Reactions ◽  
X Ray ◽  
Critical Dose

Areas on the abdomen of the same guinea pig were exposed to suberythemal doses of soft X-rays, to heat of an intensity below the critical dose for the production of burns, and to both radiations in sequence with various time intervals between the exposures. The only effect of exposure to X-ray or heat alone was a slight scaling of the skin. The areas exposed to heat and X-radiation developed well-marked and persistent burns when the exposure to one agent was made within 3 hours of the other. Scaling of the skin developed when the exposure to one agent was made 1 day after the other. This scaling was more marked and lasted longer than the scaling produced by either agent alone. The results were the same no matter in which sequence the agents were applied.

scholarly journals Correction to “On a Class of Hermite-Obreshkov One-Step Methods with Continuous Spline Extension” [Axioms 7(3), 58, 2018]

Axioms ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 59
Author(s):  
Francesca Mazzia ◽  
Alessandra Sestini
Keyword(s):  
Kepler Problem ◽  
Hamiltonian Function ◽  
First Integrals ◽  
The Other ◽  
Time Intervals ◽  
One Step ◽  
Over Time

The authors of the above mentioned paper specify that the considered class of one-step symmetric Hermite-Obreshkov methods satisfies the property of conjugate-symplecticity up to order p + r , where r = 2 and p is the order of the method. This generalization of conjugate-symplecticity states that the methods conserve quadratic first integrals and the Hamiltonian function over time intervals of length O ( h − r ) . Theorem 1 of the above mentioned paper is then replaced by a new one. All the other results in the paper do not change. Two new figures related to the already considered Kepler problem are also added.

scholarly journals When is a dynamical system mean sensitive?

2017 ◽  
Vol 39 (06) ◽  
pp. 1608-1636 ◽  
Author(s):  
FELIPE GARCÍA-RAMOS ◽  
JIE LI ◽  
RUIFENG ZHANG
Keyword(s):  
Dynamical System ◽  
Phase Space ◽  
The Other ◽  
Positive Entropy ◽  
Topological Dynamical System ◽  
Other Hand ◽  
Open Question ◽  
Uniquely Ergodic ◽  
Mean Sensitivity ◽  
Transitive System

This article is devoted to studying which conditions imply that a topological dynamical system is mean sensitive and which do not. Among other things, we show that every uniquely ergodic, mixing system with positive entropy is mean sensitive. On the other hand, we provide an example of a transitive system which is cofinitely sensitive or Devaney chaotic with positive entropy but fails to be mean sensitive. As applications of our theory and examples, we negatively answer an open question regarding equicontinuity/sensitivity dichotomies raised by Tu, we introduce and present results of locally mean equicontinuous systems and we show that mean sensitivity of the induced hyperspace does not imply that of the phase space.

The relativistic clock problem

1952 ◽  
Vol 48 (4) ◽  
pp. 608-615
Author(s):  
F. I. Mikhail
Keyword(s):  
General Relativity ◽  
Special Relativity ◽  
Relative Motion ◽  
Circular Orbit ◽  
The Other ◽  
Time Interval ◽  
Time Intervals ◽  
Test Particles ◽  
Clock Paradox ◽  
The Difference

AbstractThe so-called ‘clock paradox’ is concerned with the difference in the time-intervals reckoned by two observers in relative motion for the lapse of time between two encounters. In this paper the problem is treated purely by general relativity by considering a particular example in which the two observers are attached to two test-particles moving freely in the field of a gravitating mass; one of these makes complete revolutions in a circular orbit while the other moves radially outwards and inwards. The time-interval between two successive encounters is shorter in the reckoning of the former than in that of the latter. The difference is found to agree qualitatively with a naïve application of special relativity.

COOPERATIVE PHASE DYNAMICS IN COUPLED NEPHRONS

2001 ◽  
Vol 15 (23) ◽  
pp. 3079-3098 ◽  
Author(s):  
D. E. POSTNOV ◽  
O. V. SOSNOVTSEVA ◽  
E. MOSEKILDE ◽  
N.-H. HOLSTEIN-RATHLOU
Keyword(s):  
Chaotic Dynamics ◽  
Phase Synchronization ◽  
Functional Unit ◽  
Flow Regulation ◽  
Tubuloglomerular Feedback ◽  
Phase Dynamics ◽  
The Individual ◽  
Fast Oscillations ◽  
Coherent Behavior ◽  
Different Time Scales

The individual functional unit of the kidney (the nephron) displays oscillations in its pressure and flow regulation at two different time scales: Relatively fast oscillations associated with the myogenic dynamics of the afferent arteriole, and slower oscillations related with a delay in the tubuloglomerular feedback. Neighboring nephrons interact via vascularly propagated signals. We study the appearance of various forms of coherent behavior in a model of two such interacting nephrons. Among the observed phenomena are in-phase and anti-phase synchronization of chaotic dynamics, multistability, and partial phase synchronization in which the nephrons attain a state of chaotic phase synchronization with respect to their slow dynamics, but the fast dynamics remains desynchronized.

Sign in / Sign up

Export Citation Format

Share Document