A new scheme for optimizing direct current component in photonics-assisted OFDM MMW system

2021 ◽  
Author(s):  
Li Zhao ◽  
Bohan Sang ◽  
Wen Zhou ◽  
yi wei ◽  
Jianjun Yu
Keyword(s):  
Direct Current ◽  
Current Component

Inter-Method Reliability of Pulse Volume Related Measures Derived Using Finger-Photoplethysmography

2018 ◽  
Vol 32 (4) ◽  
pp. 182-190 ◽  
Author(s):  
Kenta Matsumura ◽  
Koichi Shimizu ◽  
Peter Rolfe ◽  
Masanori Kakimoto ◽  
Takehiro Yamakoshi
Keyword(s):  
Light Intensity ◽  
Adverse Effects ◽  
Light Source ◽  
Direct Current ◽  
Resting State ◽  
Current Component ◽  
Psychophysiological Measures ◽  
Pulse Volume ◽  
Optical Paths ◽  
Sensor Positions

Abstract. Pulse volume (PV) and its related measures, such as modified normalized pulse volume (mNPV), direct-current component (DC), and pulse rate (PR), derived from the finger-photoplethysmogram (FPPG), are useful psychophysiological measures. Although considerable uncertainties exist in finger-photoplethysmography, little is known about the extent of the adverse effects on the measures. In this study, we therefore examined the inter-method reliability of each index across sensor positions and light intensities, which are major disturbance factors of FPPG. From the tips of the index fingers of 12 participants in a resting state, three simultaneous FPPGs having overlapping optical paths were recorded, with their light intensity being changed in three steps. The analysis revealed that the minimum values of three coefficients of Cronbach’s α for ln PV, ln mNPV, ln DC, and PR across positions were .948, .850, .922, and 1.000, respectively, and that those across intensities were .774, .985, .485, and .998, respectively. These findings suggest that ln mNPV and PR can be used for psychophysiological studies irrespective of minor differences in sensor attachment positions and light source intensity, whereas and ln DC can also be used for such studies but under the condition of light intensity being fixed.

Fiber Bragg gratings with refractive index direct current component modulation

2008 ◽  
Author(s):  
Binbin Yan ◽  
Gang-Ding Peng ◽  
Kuiru Wang ◽  
Chongxiu Yu ◽  
Xiangjun Xin ◽  
...  
Keyword(s):  
Refractive Index ◽  
Direct Current ◽  
Fiber Bragg Gratings ◽  
Bragg Gratings ◽  
Current Component

Feasibility Study on the Fault Line Selection Method Based on Overall Trend of Zero Sequence Current

2013 ◽  
Vol 341-342 ◽  
pp. 1235-1238
Author(s):  
Li Gao ◽  
Hong Chun Shu
Keyword(s):  
Phase Angle ◽  
Direct Current ◽  
Initial Phase ◽  
Travelling Wave ◽  
Current Component ◽  
Fault Line ◽  
Preliminary Stage ◽  
Fault Line Selection ◽  
Zero Sequence ◽  
Line Selection

Two results were obtained by analysing electromagnetism transition condition: firstly, when the initial phase angle of fault is larger, the characteristic of travelling wave is obvious, and the polarity of the first travelling wave head is consistent with the overall trend of zero sequence current in preliminary stage; secondly, when the initial phase angle of fault is smaller, the characteristic of travelling wave is not obvious, but the fault lines and perfect lines can be recognized through the direction of decaying direct current component in zero sequence current, and the direction of decaying direct current component is consistent with the overall trend of zero sequence current in preliminary stage. Research suggests that it is feasible to make the overall trend of zero sequence current in preliminary stage as characteristic for line selection.

Calibration of photoelastic modulator using direct current component

Optik ◽  
2017 ◽  
Vol 140 ◽  
pp. 304-307
Author(s):  
Liyuan Gu ◽  
Jian Wang ◽  
Linglin Zhu ◽  
Jing Zhu ◽  
Aijun Zeng ◽  
...  
Keyword(s):  
Direct Current ◽  
Current Component ◽  
Photoelastic Modulator

The Direct Current Component of the Electroretinogram in Man

1972 ◽  
Vol 73 (2) ◽  
pp. 243-249 ◽  
Author(s):  
Kazuo Kawasaki ◽  
Yutaka Tsuchida ◽  
Jerry H. Jacobson
Keyword(s):  
Direct Current ◽  
Current Component

A WIDE RANGE VACUUM TUBE VOLTMETER CIRCUIT

1935 ◽  
Vol 12 (1) ◽  
pp. 1-5 ◽  
Author(s):  
G. A. Woonton
Keyword(s):  
Direct Current ◽  
Current Component ◽  
Vacuum Tube ◽  
Fundamental Frequencies ◽  
Wide Range ◽  
Tube Voltmeter ◽  
Conventional Type ◽  
Input Wave ◽  
Plate Current

The conventional type of vacuum tube voltmeter has been found to be unsatisfactory when used to check amplifiers designed to reproduce e.m.f's whose fundamental frequencies range from a few to 100 cycles per second. These difficulties can be overcome by the use of a symmetrical tube circuit which integrates the two halves of the input wave to produce a smoothed direct current component. Certain other advantages which result from the use of the same circuit are reported. The choice of Type 31 tubes makes the use of an inexpensive plate current meter possible.

scholarly journals Important Factors for Consideration during the Specification of SF6 Circuit Breakers for High Voltage Generators

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3608
Author(s):  
Avni Alidemaj ◽  
Qendrim Nika
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Circuit Breaker ◽  
Energy System ◽  
Fault Current ◽  
Current Component ◽  
Circuit Breakers ◽  
High Voltage Circuit Breaker ◽  
Short Time ◽  
A Current

This paper describes and analyzes the phenomena that occur in the case of a current interruption due to faults in the high voltage circuit breaker. That happens during connection of a generator to the network without meeting the synchronization conditions. This paper also describes and analyzes the important factors that have to be considered during the specification of SF6 circuit breakers for high voltage generators. A high direct current component in the fault current poses a major problem during such interruptions. To investigate this problem and propose possible solutions, simulations were performed on a power network model completed with the network’s data, using software such as EMTP-ATP, PSS-E and MATLAB. Various modes of operation were simulated, which are important for analyzing the strain on circuit breakers near the generator. Based on the performed simulations, it can be concluded that circuit breakers with rapid reactions in interrupting the fault current in an energy system are not always a favorable solution due to the high value of the direct current component in the fault current, which prevents the current from passing through zero within a short time.

Time domain parameter identification of transient electromechanical oscillations

2019 ◽  
Vol 38 (2) ◽  
pp. 574-595
Author(s):  
Julián Sotelo-Castañón ◽  
José Alberto Gutiérrez-Robles ◽  
Brian Johnson ◽  
Pablo Moreno ◽  
Armando Guzman
Keyword(s):  
Power Systems ◽  
Direct Current ◽  
Test Cases ◽  
Current Component ◽  
Observation Window ◽  
Short Delay ◽  
Content Type ◽  
Electromechanical Oscillations ◽  
Signal Parameters

Purpose The power systems behavior is nonlinear, and this is reflected in that the measurement signals are composed by multi-components. Thus, this paper aims to present a method for analyzing multi-component signals that allow calculating signal parameters such as frequency, damping constant, amplitude and phase for each component, as well as determining the direct current component. Design/methodology/approach The method proposed is based in the Z-transform of a damped sinusoidal signal with direct current. Only the Z-transform poles are used to form equation systems which are used to obtain frequency and damping. Then, the amplitude, the phase and the direct current component are determined by the above results. Findings The method is able to determine frequencies, damping constants, phases and amplitudes of the different modal components of a signal using only a few measurements. Moreover, the method does not require filter banks tuned with some previous knowledge of signal’s characteristics. The presented test cases of field measured signals show the good performance of the proposed method, which is able to obtain the parameters of interest with a very short observation window. Originality/value One quality of this method is that it has a very short delay to reach the first solution and from there you get one result each sample; the delay time is equivalent to 2 + 4C samples where C is the number of components in the signal. Finally, it is concluded that because of the small number of samples that are needed and the low algorithmic complexity of the methodology, the method is apt to make applications in real time.

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