scholarly journals Nonlinear Coupling of Drift Waves and High Frequency Fluctuation on PANTA

2017 ◽  
Vol 12 (0) ◽  
pp. 1201034-1201034
Author(s):  
Kazunobu HASAMADA ◽  
Yusuke KOSUGA ◽  
Fumiyoshi KIN ◽  
Sigeru INAGAKI ◽  
Yoshihiko NAGASHIMA ◽  
...  
Keyword(s):  
High Frequency ◽  
Frequency Fluctuation ◽  
Drift Waves ◽  
Nonlinear Coupling ◽  
High Frequency Fluctuation

Bursting high-frequency fluctuation observed in biased plasma in TU-Heliac

2014 ◽  
Vol 54 (11) ◽  
pp. 114013
Author(s):  
S. Koike ◽  
S. Kitajima ◽  
A. Okamoto ◽  
K. Ishii ◽  
Y. Sato ◽  
...  
Keyword(s):  
High Frequency ◽  
Frequency Fluctuation ◽  
High Frequency Fluctuation

scholarly journals An improved EEMD-based hybrid approach for the short-term forecasting of hog price in China

2017 ◽  
Vol 63 (No. 3) ◽  
pp. 136-148 ◽  
Author(s):  
Xiong Tao ◽  
Li Chongguang ◽  
Bao Yukun
Keyword(s):  
High Frequency ◽  
Hybrid Approach ◽  
Low Frequency ◽  
Frequency Fluctuation ◽  
Price Forecasting ◽  
Short Term ◽  
Price Series ◽  
Short Term Forecasting ◽  
High Frequency Fluctuation ◽  
Improved Eemd

Short-term forecasting of hog price, which forms the basis for the decision making, is challenging and of great interest for hog producers and market participants. This study develops improved ensemble empirical mode decomposition (EEMD)-based hybrid approach for the short-term hog price forecasting. Specifically, the EEMD is first used to decompose the original hog price series into several intrinsic-mode functions (IMF) and one residue. The fine-to-coarse reconstruction algorithm is then applied to compose the obtained IMFs and residue into the high-frequency fluctuation, the low-frequency fluctuation, and the trend terms which can highlight new features of the hog price fluctuations. Afterwards, the extreme learning machine (ELM) is employed to model the low-frequency fluctuation, while the autoregressive integrated moving average (ARIMA) and the polynomial function are used to fit the high-frequency fluctuation and trend term, respectively, in a multistep-ahead fashion. The commonly used iterated prediction strategy is adopted for the implementation of the multistep-ahead forecasting. The monthly hog price series from January 2000 to May 2015 in China is employed to evaluate the forecasting performance of the proposed approach with the selected counterparts. The numerical results indicate that the improved EEMD-based hybrid approach is a promising alternative for the short-term hog price forecasting.  

Unsteady Heat Release of Stratified Swirling Flames in a Partially Premixed Pre-Vaporized Combustor

2016 ◽  
Author(s):  
Jing Wang ◽  
Xin Hui ◽  
Hao Qin ◽  
Chi Zhang ◽  
Yuzhen Lin
Keyword(s):  
Heat Release ◽  
High Frequency ◽  
Low Frequency ◽  
Frequency Fluctuation ◽  
Band Pass Filter ◽  
Bulk Motion ◽  
Swirling Flames ◽  
Partially Premixed ◽  
Stratified Flames ◽  
High Frequency Fluctuation

Unsteady heat release of stratified swirling flames in a partially premixed pre-vaporized combustor at elevated pressure and temperature is experimentally investigated. Stratified flames produced by a pilot swirler and a main one which are fueled by different flow rates of aviation kerosene. Three fuel staging ratios (SR) of 25%, 30%, and 35% are tested to study its effect on the heat release of stratified flame. CH* chemiluminescence emissions are recorded by a high speed ICCD camera with a 430±10 nm band-pass filter. The Proper Orthogonal Decomposition (POD) analysis is employed to identify the most prominent energetic modes of flame fluctuations. Test results show that the low frequency fluctuation of the flame global heat release is weakened as the SR decreases while the high frequency fluctuation is enhanced. According to the analysis of average heat release of the flame, SR affects the structure of flame by changing the flame angle. The stratified flame dynamics mainly performs the bulk motion, asymmetric motion, and flame shedding. It is found that the flame bulk motion modes contain higher energy than those of other modes. While the other two lower energy modes would transit from asymmetric motion to flame shedding mode as the SR decreases. From the Fast Fourier Transform (FFT) analysis, the low frequency fluctuation of global heat release is dominated by modes of higher energy, while the high frequency fluctuation is related to all the modes.

High frequency drift waves with wavelengths below the ion gyroradius in equatorial spread F

1978 ◽  
Vol 5 (8) ◽  
pp. 695-698 ◽  
Author(s):  
J. D. Huba ◽  
P. K. Chaturvedi ◽  
S. L. Ossakow ◽  
D. M. Towle
Keyword(s):  
High Frequency ◽  
Frequency Drift ◽  
Drift Waves ◽  
Equatorial Spread F ◽  
Spread F

Stabilization of drift waves by a non-uniform high-frequency field

1971 ◽  
Vol 11 (2) ◽  
pp. 167-175 ◽  
Author(s):  
T.I. Gutkin ◽  
G.I. Boleslavskaya
Keyword(s):  
High Frequency ◽  
Drift Waves ◽  
High Frequency Field ◽  
Frequency Field

scholarly journals Modulational instabilities of surface plasmons on metallic plasma surfaces with nanoparticles

2008 ◽  
Vol 74 (3) ◽  
pp. 287-291 ◽  
Author(s):  
P. K. SHUKLA ◽  
L. STENFLO
Keyword(s):  
Surface Plasmons ◽  
Growth Rates ◽  
High Frequency ◽  
Low Frequency ◽  
Finite Amplitude ◽  
Nonlinear Coupling ◽  
Charged Nanoparticles ◽  
Modulational Instabilities

AbstractThe nonlinear coupling between high-frequency surface plasmons (SPs) and low-frequency ion oscillations on metallic plasma surfaces with charged nanoparticles is considered. It is shown that a finite-amplitude SP wave is modulationally unstable against the excitation of non-resonant ion oscillations. The growth rates and thresholds of the modulational instabilities are presented.

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