Integrated noise

The external review pointed up several types of occurrences that had to be addressed at the laboratories. In some cases, corrections had to be made, for example if elution peaks had been misidentifled or if the laboratory data system integrated noise and reported a peak where there was none. Such occurrences were observed primarily in the early stages of the study and decreased as the laboratories refined integration parameters for their individual commodities. In other cases, it became apparent that... 

The uncertainty in the determination of the area of a prak c us l by (stationary) noise can be calculated both in the time domain and in the frequency domain. In a derivation ofctf, i.e. the variance of the integrated noise, is given ... 

Fig. 10. Calibration graph for phenol with fluorimetric detection for 5 concentrations (I0" to lO" gl ) s indicates single injection and c indicates correlation chromatography. The numbers below the data points indicate the correlation time (minutes) (ppt = ng 1" ). The bars represent 3 x standard deviation of the integrated noise (confidence interval).

The minimum U = 1 is assumed for a constant white power spectrum with X[k] 2 = N. All deviations from the constant power spectrum increase the integral noise amplification U. They may, however, be useful for noise suppression at... 

The energy E of this spin system may be defined as the integral noise amplification U as given in Eq. (70), which can be expressed as a function of the pair products of all spins ... 

The problem of determining the variance of integrated noise is not restricted to peak parameter determination. Measurement and calculation of the average intensity of a spectroscopic line means integrating too, however, the final result including the standard deviation of the integrated noise has to be divided by the integration time. 

P2(T) has to be minimized with respect to T. The normalized integrated peak area in case of a known peak shape is known, and we have derived an expression for the integrated noise variance. As usual, we can determine the derivative, setting it equal to zero and the desired result can be calculated. This procedure leads to ... 

Figure 9. Standard deviation of the integrated noise after drift correction versus the integration time, with the correction interval width as a parameter.

The rms fluctuations in the GMR signal are proportional to the integrated noise spectrum A0, which we approximate as the product of Eq.23 and the square root of the electronic bandwidth A/-... 

For integer a, a closed loop expression of the integrated noise after derivative (Ni) can be obtained from (58). With a further assumption that the sampling frequency is sufficiently higher than the signal spectrum, the expression of Ni could be generalized to noninteger a as ... 

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