The analysis showed that the errors of amplitude mainly depend on aperture angle θ, the other parameters such as frequency f,velocity υand normal distance z only have limited influence on errors of phase.

This paper introduces the basic idea of applying DSP in the measuring of electric power parameters. The method is given to compensate errors of active power and reactive power caused by errors of phase.

The usual adaptive filter can not be directly used in an active noise control system because there is an acoustic channel between the loudspeaker and the error microphone, and this acoustic channel will enable the system unstable. Based on the phase characteristic of the acoustic channel, we propose a method such that the transmission characteristic of the acoustic channel can be identified experimently. In room test, the errors of phase factor of a single channel are studied.

This paper analyses the reasons causing non linear error when the phase difference is close to 0° or 360°, and proposes a method of inverting phase to eliminate the non linear errors of phase detector. It is proved that the measurement accuracy of the phase detector at higher comparing frequency has been improved.

Phase difference is the main reason which can lead to measuring errors in Sound Intensity Measurement. In this thesis,the main reason which lead to phase difference can be found by calculation and analysis,and update methods with errors of phase difference of system can be posed in the measurement way of FFT.

A system for balancing out the systematic errors of phase-measuring instruments

For that, the errors of phase angle and amplitude of the measuring transformers must be known.

The determination of the errors of phase angle and amplitude of measuring transformers is carried out on the basis of calibrated standard measuring transformers which are traceable to national standard equipment at rated frequency, e.g.

For the load loss measurement of power transformers, current and voltage transformers with usually extremely low errors of phase angle and amplitude are used.

This paper gives a simplified method which can be used to reduce the order of high-order system. This method is based on following: if the reduced frequency-response characteristics are compared with those which are not reduced, the error of logarithmic magnitude characteristics is lessthan 1 dB, and the error of phase-angle characteristics is less than 5 degree.Within certain range of frequency, then, this reduction is a success. Thus, the reduced system doesn't change the stability of the original...

This paper gives a simplified method which can be used to reduce the order of high-order system. This method is based on following: if the reduced frequency-response characteristics are compared with those which are not reduced, the error of logarithmic magnitude characteristics is lessthan 1 dB, and the error of phase-angle characteristics is less than 5 degree.Within certain range of frequency, then, this reduction is a success. Thus, the reduced system doesn't change the stability of the original system.This paper develops detailed calculations for the reduction of some ordinary links and systems, and proves the rationality of this reduction separately from complex frequency-domain and time-domain. We think this"5 °- ldB" method which is introduced in this paper is worth using.

In this paper, the effect of Legendre expansion of scattering phase function with a finite number of terms on solving radiative transfer equation is studied and an improved algorithm suggested.Both theoretical analysis and numerical experiments have shown that the multiple-scattering component of radiance and radiative flux are not much more sensitive to the expansion error of phase function than the single-scattering component, and through correcting the single-scattering component by the exact...

In this paper, the effect of Legendre expansion of scattering phase function with a finite number of terms on solving radiative transfer equation is studied and an improved algorithm suggested.Both theoretical analysis and numerical experiments have shown that the multiple-scattering component of radiance and radiative flux are not much more sensitive to the expansion error of phase function than the single-scattering component, and through correcting the single-scattering component by the exact phase function, an accurate radiance solution can be obtained under Legendre expansion of phase function with less terms, thus the computing time can be down by a factor of about 5 for the optical depth less than unity.

A discussion is made on the relationship between the random error of the time and phase measurements and the signal-to-noise ratio when range and phase are determined by an acoustic transponder. The rms error of time measurements is given and the rms error of phase-descri-minating signal. in a homogenuous limited band white noise field is slso provided.