scholarly journals Steady-state rotational motion of the Photon M-2 satellite

2021 ◽  
pp. 1-36
Author(s):  
Denis Mikhailovich Bulanov ◽  
Victor Vasil’yevich Sazonov
Keyword(s):  
Low Frequency ◽  
Conservative System ◽  
Frequency Component ◽  
Secular Change ◽  
Order System ◽  
Attitude Motion ◽  
Secular Motion ◽  
Axis Of Symmetry ◽  
The Relationship ◽  
Kinetic Moment

At the end of the flight, the attitude motion of the Photon M-2 satellite (it was in orbit 2005.05.31-2005.06.16) can be described by a generalized conservative system of differential equations. The secular change in the own kinetic moment of this satellite is described by the so-called evolutionary equations of Beletsky, which also form a generalized conservative system. The preprint examines the relationship between these systems. The satellite motion equations are reduced to equations of the 4th order describing the motion of the satellite axis of symmetry. Beletsky's equations are of the second order and describe the secular motion of the ort of the satellite's own kinetic moment. The solutions of these systems of equations corresponding to the real movements of the satellite are, respectively, conditionally periodic and periodic. The solutions of the 4th-order system are dominated by two frequencies – high and low ones. The spectral analysis showed that the low frequency coincides with the frequency of solutions of Beletsky’s equations. And the solutions of these equations coincide with the low-frequency component in the solution of the 4th-order system with respect to the variables that determine the direction of the axis of symmetry of the satellite.

LOW-FREQUENCY VOLATILITY AND MACROECONOMIC DYNAMICS: CONVENTIONAL VERSUS ISLAMIC STOCK MARKETS

2020 ◽  
pp. 1-28 ◽  
Author(s):  
HONG-BAE KIM ◽  
A.S.M. SOHEL AZAD
Keyword(s):  
Interest Rates ◽  
Stock Markets ◽  
Low Frequency ◽  
Frequency Component ◽  
Market Volatility ◽  
Macroeconomic Dynamics ◽  
Macroeconomic Factors ◽  
Macroeconomic Risk ◽  
Islamic Countries ◽  
The Relationship

This study investigates the relationship between macroeconomic risk and low-frequency volatility of conventional and Islamic stock markets from around the world. Using a panel of 36 countries, representing developed, emerging and Islamic countries for the period from 2000 to 2016, the study finds that low-frequency market volatility is lower for Islamic countries and, markets with more number of listed companies, higher market capitalization relative to GDP and larger variability in industrial production. The study also finds that low-frequency component of volatility is greater when the macroeconomic factors of GDP, unemployment, short-term interest rates, inflation, money supply and foreign exchange rates are more volatile. The empirical results are robust to various alternative specifications and split sample analyses. The findings imply that religiosity has an influence on the correction of market volatility and investors may consider the Islamic stocks to diversify their risks.

scholarly journals Intensity Variations in Extragalactic Radio Sources at 13 cm

1972 ◽  
Vol 44 ◽  
pp. 224-224 ◽  
Author(s):  
G. D. Nicolson
Keyword(s):  
Low Frequency ◽  
Secular Change ◽  
Radio Sources ◽  
Complete Sample ◽  
Frequency Spectra ◽  
Extragalactic Radio Sources ◽  
The Relationship

Results of a three-year investigation into the variability of 55 Parkes sources at 13 cm are presented. Thirty-six of the sources comprise a complete sample of QSS with fluxes exceeding 2 flux units. The remaining sources include most other known or likely variables stronger than 2 flux units. The relationship between spectra and variability in QSS is investigated and it is confirmed that variables generally have flat low frequency spectra. A possible relationship between redshift and specific types of intensity variations is considered. Limits on the secular change in the intensity of non-variable QSS are set and are generally found to be ± 1.5% p.a. at 13 cm. Results for the remaining 19 sources are discussed and some preliminary findings of an extension patrol to include weaker sources in the range 1-2 flux units are given.

scholarly journals Observación automatizada: la variabilidad de la frecuencia cardíaca y su relación con las variables psicológicas determinantes del rendimiento en nadadores jóvenes

2017 ◽  
Vol 33 (3) ◽  
pp. 436 ◽  
Author(s):  
Jesús M. Ortigosa-Márquez ◽  
Rafael E. Reigal ◽  
Mariona Portell ◽  
Verónica Morales-Sánchez ◽  
Antonio Hernández-Mendo
Keyword(s):  
Sleep Quality ◽  
Low Frequency ◽  
Frequency Component ◽  
Self Esteem ◽  
High Frequency Component ◽  
Quality Performance ◽  
Psychological Variables ◽  
Psychological Determinants ◽  
Predicting Performance ◽  
The Relationship

<p style="margin: 0cm 0cm 0pt; line-height: 150%;"><span style="font-size: medium;"><span style="font-family: 'Times New Roman',serif; mso-ansi-language: EN-US;" lang="EN-US">Correct interpretation of performance markers from</span><span style="font-family: 'Times New Roman',serif; mso-ansi-language: EN-US; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi;" lang="EN-US"> a psychophysiological perspective is important in young developing athletes. This study had two objectives. The first was to analyze the relationship between heart rate variability (HRV) and the psychological variables sleep quality, self-esteem, and mood states in young swimmers from a professional swimming club. The second was to study the relationship between performance and HRV and psychological determinants. The sample was composed of nine swimmers (11.7<span style="color: #1c1c1c;">±1.4 years) base on purposive sampling method. Data were collected once a week during training sessions for 3 weeks. The statistical analysis showed that anxiety was negatively correlated with the high frequency component of HRV (Ln HF) and positively correlated with the very low frequency component (Ln LVF). No significant correlations were observed for self-esteem or sleep quality. Performance in a 200-m freestyle event was negatively correlated with the parasympathetic HRV indices. Our results suggest that HRV could be a valid tool for predicting performance and improving interpretation of psychometric tests. </span></span></span></p>

Acceleration sound design for vehicles using distortion products

2021 ◽  
Vol 263 (4) ◽  
pp. 2494-2500
Author(s):  
Yu Aburagi ◽  
Natsuki Yamagiwa ◽  
Noriyuki Tanimoto ◽  
Shunsuke Ishimitsu ◽  
Mitsunori Matsumoto ◽  
...  
Keyword(s):  
Low Frequency ◽  
Frequency Component ◽  
Second Step ◽  
Sound Design ◽  
Complex Sounds ◽  
Acoustic Design ◽  
Distortion Products ◽  
Order Components ◽  
The Relationship ◽  
Different Order

When considering the acoustic design of automobiles, low-frequency sounds can increase the excitement levels for users. However, there are several problems accompany an increase in the low-frequency levels of an engine sound. For example, it is difficult to create a balance between silence and excitement when a sound's different order components are changed. It is also difficult to generate heavy bass engine sounds in practical scenarios. Thus, the application of distortion products in the auditory system of the cochlea is considered. Distortion products are perceived when two or more sounds with slightly different frequencies are played simultaneously. This study was conducted to examine the possibility of achieving powerful engine sounds using distortion products. At first, the relationship between different combinations of complex sounds and the pitch perception of distortion products was investigated. As a second step, the application of distortion products to the acceleration sound was also considered. The results suggested the possibility of synthesizing a low-frequency component using distortion products inside a cochlea.

The Relationship Between Ictal Multi-Unit Activity and the Electrocorticogram

2018 ◽  
Vol 28 (10) ◽  
pp. 1850027 ◽  
Author(s):  
Tahra L. Eissa ◽  
Catherine A. Schevon ◽  
Ronald G. Emerson ◽  
Guy M. Mckhann ◽  
Robert R. Goodman ◽  
...  
Keyword(s):  
Microelectrode Array ◽  
Linear Time ◽  
Physiological Mechanism ◽  
Low Frequency ◽  
Frequency Component ◽  
Sinc Function ◽  
Brick Wall ◽  
Linear Time Invariant ◽  
Linear Time Invariant System ◽  
The Relationship

During neocortical seizures in patients with epilepsy, microelectrode array recordings from the ictal core show a strong correlation between the fast, cellular spiking activities and the low-frequency component of the potential field, reflected in the electrocorticogram (ECoG). Here, we model the relationship between the cellular spike activity and this low-frequency component as the input and output signals of a linear time invariant system. Our approach is based on the observation that this relationship can be characterized by a so-called sinc function, the unit impulse response of an ideal (brick-wall) filter. Accordingly, using a brick-wall filter, we are able to convert ictal cellular spike inputs into an output that significantly correlates with the observed seizure activity in the ECoG [Formula: see text], while ECoG recordings of subsequent seizures within patients also show significant, but lower, correlations [Formula: see text]. Furthermore, we can produce seizure-like output signals using synthetic spike trains with ictal properties. We propose a possible physiological mechanism to explain the observed properties associated with an ideal filter, and discuss the potential use of our approach for the evaluation of anticonvulsant strategies.

Practical High Resolution Microscopy

1968 ◽  
Vol 26 ◽  
pp. 302-303
Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Resolving Power ◽  
Careful Attention ◽  
Electron Microscopes ◽  
The Relationship ◽  
High Resolution Microscopy ◽  
New Facilities

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.

scholarly journals Slithering CSF: Cerebrospinal Fluid Dynamics in the Stationary and Moving Viper Boa, Candoia aspera

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 672
Author(s):  
Bruce A. Young ◽  
Skye Greer ◽  
Michael Cramberg
Keyword(s):  
Cerebrospinal Fluid ◽  
Cardiac Cycle ◽  
Low Frequency ◽  
Mean Amplitude ◽  
The Body ◽  
Body Waves ◽  
Lower Amplitude ◽  
Lateral Undulation ◽  
Recovery From Anesthesia ◽  
The Relationship

In the viper boa (Candoia aspera), the cerebrospinal fluid (CSF) shows two stable overlapping patterns of pulsations: low-frequency (0.08 Hz) pulses with a mean amplitude of 4.1 mmHg that correspond to the ventilatory cycle, and higher-frequency (0.66 Hz) pulses with a mean amplitude of 1.2 mmHg that correspond to the cardiac cycle. Manual oscillations of anesthetized C. aspera induced propagating sinusoidal body waves. These waves resulted in a different pattern of CSF pulsations with frequencies corresponding to the displacement frequency of the body and with amplitudes greater than those of the cardiac or ventilatory cycles. After recovery from anesthesia, the snakes moved independently using lateral undulation and concertina locomotion. The episodes of lateral undulation produced similar influences on the CSF pressure as were observed during the manual oscillations, though the induced CSF pulsations were of lower amplitude during lateral undulation. No impact on the CSF was found while C. aspera was performing concertina locomotion. The relationship between the propagation of the body and the CSF pulsations suggests that the body movements produce an impulse on the spinal CSF.

The Lightning Electromagnetic Pulse Coupling Effect Inside the Shielding Enclosure With Penetrating Wire

Frequenz ◽  
2017 ◽  
Vol 71 (11-12) ◽  
Author(s):  
Xue Jiao ◽  
Bo Yang
Keyword(s):  
Electromagnetic Pulse ◽  
Coupling Effect ◽  
Fdtd Method ◽  
Current Source ◽  
Low Frequency ◽  
Frequency Component ◽  
Lightning Current ◽  
Proper Size ◽  
Practical Engineering ◽  
Difference Time

AbstractTo study the lightning electromagnetic pulse (LEMP) coupling and protection problems of shielding enclosure with penetrating wire, we adopt the model with proper size which is close to the practical engineering and the two-step finite-difference time-domain (FDTD) method is used for calculation in this paper. It is shown that the coupling voltage on the circuit lead inside the enclosure increases about 34 dB, when add 1.0 m long penetrating wire at the aperture, comparing with the case without penetrating wire. Meanwhile, the waveform, has the same wave outline as the lightning current source, shows that the penetrating wire brings a large number of low frequency component into the enclosure. The coupling effect in the enclosure will reduce greatly when penetrating wire has electrical connection with the enclosure at the aperture and the coupling voltage increase only about 12 dB than the case without penetrating wire. Moreover, the results show that though the waveguide pipe can reduce the coupling effect brought by the penetrating wire, the exposing part of penetrating wire can increase the coupling when the penetrating wire outside the enclosure is longer than the waveguide pipe and the longer the exposing part is, the stronger the coupling is.

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