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Systematic errors description

The flowsheet shown in the introduction and that used in connection with a simulation (Section 1.4) provide insights into the pervasiveness of errors at the source, random errors are experienced as an inherent feature of every measurement process. The standard deviation is commonly substituted for a more detailed description of the error distribution (see also Section 1.2), as this suffices in most cases. Systematic errors due to interference or faulty interpretation cannot be detected by statistical methods alone control experiments are necessary. One or more such primary results must usually be inserted into a more or less complex system of equations to obtain the final result (for examples, see Refs. 23, 91-94, 104, 105, 142. The question that imposes itself at this point is how reliable is the final result Two different mechanisms of action must be discussed ... [Pg.169]

The ultimate goal of multivariate calibration is the indirect determination of a property of interest (y) by measuring predictor variables (X) only. Therefore, an adequate description of the calibration data is not sufficient the model should be generalizable to future observations. The optimum extent to which this is possible has to be assessed carefully when the calibration model chosen is too simple (underfitting) systematic errors are introduced, when it is too complex (oveifitting) large random errors may result (c/. Section 10.3.4). [Pg.350]

So far, we have been mainly following the most logical route from an ansatz for the DM1 to its resulting OF-KEDF. However, if the DM1 and the XEDF or more general XCEDF are not om major interests, is there any simpler way to approximate the OF-KEDF This is indeed a legitimate question. First, munerous numerical tests show that the WDA and the ADA only improve the description of the XCEDF marginally it is very hard to further refine the systematic error cancellation built in the EDA for the XCEDF.. . i36 i4i,26o,3i5 318,32M42 p j. [Pg.154]

The deviations due to some of these destructive influences are reversible. These are usually described as systematic errors. Many of the degradation processes that affect images and most recorded data are classified as systematic errors. For many of these cases the error may be expressed as a function known as the impulse response function. Much mathematical theory has been devoted to its description and correction of the degradation due to its influence. This has been discussed in some detail by Jansson in Chapter 1 of this volume. In that correction of this type of error usually involves increasing the higher frequencies of the Fourier spectrum relative to the lower frequencies, this operation (deconvolution) may also be classified as an example of form alteration. ... [Pg.263]

The approximate nature of a model of this kind, the large number of parameters needed for its description, and the likely occurrence of many overlapping interactions, can make the results ambiguous and lead to systematic errors in the refined parameter values. Usually, therefore, diffraction data for a single solution are not sufficient for a complete and unbiased derivation of the structure of a specific complex. If iso-structural substitution can be used to eliminate some of the pair interactions, then much more precise and detailed information about the... [Pg.168]

The orthodox and standard quantum measurement theory uses a probability density view focused on the particle conception. The physical nature of the interaction that may lead to an event (click) is not central. Generally, it is true that a click will be eliciting the quantum state, but due to external factors, a click can be related to noise or any source of systematic error (lousy detectors) from the QM viewpoint developed here such events have no direct QM-related cause see Ref. [17], The probabilities cannot be primary. They can be useful as actually they are. One thing is sure the clicks do have a cause. But causality is a concept more related to a particle description it belongs to classical physics. [Pg.70]

The direction of the deviations between the theoretical and experimental data. Are the deviations randomly distributed, sometimes above and sometimes below the curve, or are they clustered, above the curve in one region and below in another If the deviations are not randomly distributed, this indicates that the theoretical curve is not a satisfactory fit to the experimental data. One reason for this is that the model is wrong and is not an adequate description of the situation another is that systematic errors have been made in carrying out the experiment. [Pg.324]

Bias errors are systematic errors that do not have a mean value of zero and that cannot be attributed to an inadequate descriptive model of the system. Bias errors can arise from instrument artifacts, parts of the measured system that are not part of the system under investigation, and nonstationary behavior of the system. Some types of bias errors lead the data to be inconsistent with the Kramers-Kronig relations. In those cases, bias errors can be identified by checking the impedance data for inconsistencies with the Kramers-Kronig relations. As some bias errors are themselves consistent with the Kramers-Kronig relations, the Kramers-Kronig relations cannot be viewed as providing a definitive tool for identification of bias errors. [Pg.414]

The objective of any review of experimental values is to evaluate the accuracy and precision of the results. The description of a procedure for the selection of the evaluated values (EvV) of electron affinities is one of the objectives of this book. The most recent precise values are taken as the EvV. However, this is not always valid. It is better to obtain estimates of the bias and random errors in the values and to compare their accuracy and precision. The reported values of a property are collected and examined in terms of the random errors. If the values agree within the error, the weighted average value is the most appropriate value. If the values do not agree within the random errors, then systematic errors must be investigated. In order to evaluate bias errors, at least two different procedures for measuring the same quantity must be available. [Pg.97]

If all or a large majority of the data show positive or negative deviations from the zero line, systematic errors, a weakness of the chosen model (e.g., wrong description of the vapor phase nonidealities), or a failure of the regression program can be the reason. The parameter fit must not be accepted. [Pg.702]

Where Aij (x , x ,2) is the 3D NOESY-NOESY volume and r, is the interproton distance between spins a and b. This model provides a simple description of the 3D NOESY-NOESY interaction, however it does not include the effects of spin diffusion (multiple relaxation pathways). This oversimplification leads to dramatic systematic errors in the form of overestimation of all distances. [Pg.168]


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See also in sourсe #XX -- [ Pg.6 ]

See also in sourсe #XX -- [ Pg.255 ]




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Errors description

Systematic errors

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