scholarly journals North-south asymmetry of ultra-low-frequency oscillations of Earth’s electromagnetic field

2017 ◽  
Vol 3 (4) ◽  
pp. 27-33
Author(s):  
Анатолий Гульельми ◽  
Anatol Guglielmi ◽  
Борис Клайн ◽  
Boris Klain ◽  
Александр Потапов ◽  
...  
Keyword(s):  
Nonlinear Dynamical System ◽  
Low Frequency ◽  
Auroral Oval ◽  
Forced Oscillations ◽  
Structural Elements ◽  
Geomagnetic Equator ◽  
Nonlinear Dynamical ◽  
Low Frequency Oscillations ◽  
Electromagnetic Oscillations ◽  
South Asymmetry

In the paper, we present the result of an experimental study of north-south asymmetry of ultra-low-frequency electromagnetic oscillations IPCL. This study is based on observations made at obs. Mirny (Antarctica). IPCL are excited in the dayside sector of the auroral oval in the range of 3–10 min periods and represent one of the most powerful types of oscillations of Earth’s magnetosphere. These oscillations were discovered in the 1970s during IPhE AS USSR polar expeditions organized by Prof. V.A. Troitskaya. We have shown that IPCL activity in Mirny depends on the inclination (north-south asymmetry) of interplanetary magnetic field (IMF) lines to the plane of the geomagnetic equator before the front of the magnetosphere. The result suggests a controlling exposure of IMF on the magnetospheric oscillations and gives rise to the hypothesis that IPCL are forced oscillations of a nonlinear dynamical system whose major structural elements are dayside polar cusps. The paper is dedicated to the memory of Professor V.A. Troitskaya (1917–2010).

scholarly journals North-south asymmetry of ultra-low-frequency oscillations of Earth’s electromagnetic field

2017 ◽  
Vol 3 (4) ◽  
pp. 26-31 ◽  
Author(s):  
Анатолий Гульельми ◽  
Anatol Guglielmi ◽  
Борис Клайн ◽  
Boris Klain ◽  
Александр Потапов ◽  
...  
Keyword(s):  
Nonlinear Dynamical System ◽  
Low Frequency ◽  
Auroral Oval ◽  
Forced Oscillations ◽  
Structural Elements ◽  
Nonlinear Dynamical ◽  
Ultralow Frequency ◽  
Low Frequency Oscillations ◽  
Electromagnetic Oscillations ◽  
South Asymmetry

In the paper, we present the result of an experimental study of north-south asymmetry of ultralow-frequency electromagnetic oscillations IPCL. This study is based on observations made at Mirny Observatory (Antarctica). IPCLs are excited in the dayside sector of the auroral oval in the range 3–10 min periods and represent one of the most powerful types of oscillations of Earth's magnetosphere. These oscillations were discovered in the 1970s during IPhE AS USSR polar expeditions organized by Prof. V.A. Troitskaya. We have shown that IPCL activity in Mirny depends on the inclination (north-south asymmetry) of interplanetary magnetic field (IMF) lines to the plane of the geomagnetic equator before the front of the magnetosphere. The result suggests a controlling exposure of IMF on the magnetospheric oscillations and gives rise to the hypothesis that IPCL are forced oscillations of a nonlinear dynamical system whose major structural elements are dayside polar cusps. The paper is dedicated to the memory of Professor V.A. Troitskaya (1917–2010).

scholarly journals Identification of Low Frequency Oscillations Based on Multidimensional Features and ReliefF-mRMR

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2762 ◽  
Author(s):  
Feng ◽  
Chen ◽  
Tang
Keyword(s):  
Power Systems ◽  
New England ◽  
System Analysis ◽  
Oscillation Mode ◽  
Low Frequency ◽  
Forced Oscillations ◽  
Support Vector ◽  
Feature Subset ◽  
Natural Oscillations ◽  
Low Frequency Oscillations

Low frequency oscillations (LFOs) in power systems usually fall into two types, i.e., forced oscillations and natural oscillations. Waveforms of the two are similar, but the suppression methods are different. Therefore, it is important to accurately identify LFO type. In this paper, a method for discriminating LFO type based on multi-dimensional features and a feature selection algorithm combining ReliefF and minimum redundancy maximum relevance algorithm (mRMR) is proposed. Firstly, 53 features are constructed from six aspects—time domain, frequency domain, energy, correlation, complexity, and modal analysis—which comprehensively characterize the multidimensional features of LFO. Then, the optimal feature subset with greater relevance and less redundancy is extracted by ReliefF-mRMR. In order to improve the classification performance, a modified Support Vector Machine (SVM) with Genetic Algorithm (GA) optimizing the key parameters is adopted, which is conducted in MATLAB. Finally, in 179-bus system, the samples of LFOs are generated by the Power System Analysis Toolbox (PSAT) and the accuracy of the LFO type identification model is verified. In ISO New England and East China power grid, it is proven that the proposed method can accurately identify LFO type considering the influences of noise, oscillation mode, and data incompletion. Hence, it has good robustness, noise immunity, and practicability.

Prediction of Solutions of the Duffing System with Tuned Mass Damper

2020 ◽  
Vol 22 (4) ◽  
pp. 983-990
Author(s):  
Konrad Mnich
Keyword(s):  
Dynamical System ◽  
Duffing Oscillator ◽  
Probabilistic Approach ◽  
Nonlinear Dynamical System ◽  
Tuned Mass Damper ◽  
Nonlinear Dynamical ◽  
Duffing System ◽  
Mass Damper ◽  
Basin Stability ◽  
Stability Concept

AbstractIn this work we analyze the behavior of a nonlinear dynamical system using a probabilistic approach. We focus on the coexistence of solutions and we check how the changes in the parameters of excitation influence the dynamics of the system. For the demonstration we use the Duffing oscillator with the tuned mass absorber. We mention the numerous attractors present in such a system and describe how they were found with the method based on the basin stability concept.

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