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Related papers: Stable Solar Periodicities: The Time Stability

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A fundamental description of time can be consistent not only with the usual monotonic behavior but also with a periodic physical clock variable, coupled to the degrees of freedom of a system evolving in time. Generically, one would in fact…

Quantum Physics · Physics 2022-05-25 Martin Bojowald , Luiz Martinez , Garrett Wendel

The increasing penetration of non-synchronous renewable energy sources (NS-RES) alters the dynamic characteristic, and consequently, the frequency behaviour of a power system. To accurately identify these changing trends and address them in…

Systems and Control · Computer Science 2017-08-03 Ahmad Shabir Ahmadyar , Shariq Riaz , Gregor Verbic , Archie Chapman , David J. Hill

We analyzed intermittency in the solar wind, as observed on the ecliptic plane, looking at magnetic field and velocity fluctuations between 0.3 and 1 AU, for both fast and slow wind and for compressive and directional fluctuations. Our…

Astrophysics · Physics 2015-06-24 R. Bruno , V. Carbone , L. Sorriso-Valvo , B. Bavassano

Context. Solar activity cycles vary in amplitude and duration. The variations can be at least partly explained by fluctuations in dynamo parameters. Aims. We want to restrict uncertainty in fluctuating dynamo parameters and find out which…

Solar and Stellar Astrophysics · Physics 2018-07-18 L. L. Kitchatinov , A. V. Mordvinov , A. A. Nepomnyashchikh

In this paper, we demonstrate the importance of embedding temporal information for an accurate prediction of solar irradiance. We have used two sets of models for forecasting solar irradiance. The first one uses only time series data of…

Solar and Stellar Astrophysics · Physics 2021-10-20 T. A. Fathima , Vasudevan Nedumpozhimana , Yee Hui Lee , Soumyabrata Dev

Seismology allows for direct observational constraints on the interior structures of stars and planets. Recent observations of Saturn's ring system have revealed the presence of density waves within the rings excited by oscillation modes…

Earth and Planetary Astrophysics · Physics 2015-04-30 Jim Fuller

Using the input energy per cycle as a quantifier of stochastic resonance (SR), we show that SR is observed in superharmonic (hard) potentials. However, it is not observed in subharmonic (soft) potentials, even though the potential is…

Statistical Mechanics · Physics 2012-11-02 Shubhashis Rana , Sourabh Lahiri , A. M. Jayannavar

The solar-cyle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic…

Solar and Stellar Astrophysics · Physics 2016-12-07 R. Howe , S. Basu , G. R. Davies , W. H. Ball , W. J. Chaplin , Y. Elsworth , R. Komm

Using wavelet analysis approach, the temporal variations of solar activity on time scales ranging from days to decades, are examined from the daily time series of sunspot numbers. A hierarchy of changing complex periods are careful detected…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Stefano Sello

Solar activity undergoes a variation over time scales of several months known as Rieger-type periodicity, which usually occurs near maxima of sunspot cycles. An early analysis showed that the periodicity appears only in some cycles, and is…

We investigate different measures of stability of quantum statistical ensembles with respect to local measurements. We call a quantum statistical ensemble "stable" if a small number of local measurements cannot significantly modify the…

Quantum Physics · Physics 2018-02-15 Walter Hahn , Boris V. Fine

Millisecond and binary pulsars are the most stable astronomical standards of frequency. They can be applied to solving a number of problems in astronomy and time-keeping metrology including the search for a stochastic gravitational wave…

Solar and Stellar Astrophysics · Physics 2015-05-14 Sergei Kopeikin

In electric power systems delivering alternating current, it is essential to maintain its synchrony of the phase with the rated frequency. The synchronization stability that quantifies how well the power-grid system recovers its synchrony…

Physics and Society · Physics 2019-10-24 Heetae Kim , Mi Jin Lee , Sang Hoon Lee , Seung-Woo Son

The ongoing energy transition challenges the stability of the electrical power system. Stable operation of the electrical power grid requires both the voltage (amplitude) and the frequency to stay within operational bounds. While much…

Systems and Control · Electrical Eng. & Systems 2021-12-07 Eder Batista Tchawou Tchuisseu , Eric-Donald Ndogmo , Pavel Procházka , Paul Woafo , Pere Colet , Benjamin Schäfer

The following work is motivated by the conceptual problems associated with the wave-particle duality and the notion of the photon. Two simple classical models for radiation from individual emitters are compared, one based on sines with…

Quantum Physics · Physics 2015-05-20 Borys Jagielski , Johanne Lein , Arnt Inge Vistnes

It is widely reported that the power spectra of magnetic field and velocity fluctuations in the solar wind have power law scalings with inertial-range spectral indices of -5/3 and -3/2 respectively. Studies of solar wind turbulence have…

Solar and Stellar Astrophysics · Physics 2018-09-26 Trevor A. Bowen , Alfred Mallet , John W. Bonnell , Stuart D. Bale

Context. In time-distance helioseismology, wave travel times are measured from the two-point cross-covariance function of solar oscillations and are used to image the solar convection zone in three dimensions. There is, however, also…

Solar and Stellar Astrophysics · Physics 2017-03-08 Kaori Nagashima , Damien Fournier , Aaron C. Birch , Laurent Gizon

Instabilities described by linear theory characterize an important form of wave-particle interaction in the solar wind. We diagnose unstable behavior of solar wind plasma between 0.3 and 1 au via the Nyquist criterion, applying it to fits…

Solar and Stellar Astrophysics · Physics 2021-12-22 Mihailo M. Martinovic , Kristopher G. Klein , Tereza Durovcova , Benjamin L. Alterman

In this paper we investigate spectral and phase coherence properties of magnetic fluctuations in the vicinity of the spectral transition from large, magnetohydrodynamic (MHD) to sub-ion scales using in-situ measurements of the Wind…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sonny Lion , Olga Alexandrova , Arnaud Zaslavsky

It is by now established that, remarkably, the addition of noise to a nonlinear system may sometimes facilitate, rather than hamper the detection of weak signals. This phenomenon, usually referred to as stochastic resonance, was originally…

Condensed Matter · Physics 2009-10-31 Redouane Fakir