Accuracy defined

The optimum can be located with a high degree of accuracy (defined by the user). 

Simulation calculations on finite systems will entail some error associated with the submacroscopic size considered (Lebowitz and Percus, 1961a b 1963). For example, periodic boundary conditions will influence molecular correlations to some extent (Pratt and Haan, 1981a b). Support of a claim of accuracy would typically involve some practical investigation of the thermodynamic limit. A claim of preference for calculations in one ensemble over another is typically made first on the basis of convenience rather than on the basis of accuracy defined in some absolute way. Thus, advantages of practical accuracy for ensemble-specialized alternatives to Eq. (3.18) are not proven typically, and they are not necessary fundamentally. 

Accuracy defines how closely the measured concentration agrees with the true (fortified) value. For most analytical applications, laboratories should achieve a level of accuracy within 5-10% of certified concentrations in reference materials. Accuracy is often expressed as a percentage difference from the true value ... 

Criterion 1 - the achieving of the system target state the variation of which in less than the control accuracy defined by the design is considered satisfying... 

Statistical methods provide tools for assessing univariate data (replicate measurements of a single parameter) resulting in measurements of i) accuracy, defined as the difference between an experimental value and the true value the latter is generally not known for a real-world analytical sample, so that accuracy must be estimated using a surrogate sample e.g., a blank matrix spiked with a known amount of analytical standard) ii) precision, such as the relative standard deviation (RSD, also known as the coefficient of variance, COV or CV) iii) methods for calculation of propagation of experimental error in calculations. 

The accuracy defined as the deviation of deduced concentrations from the respective true values depends first on the accuracy obtained in the calibration of the measuring configuration. For thin samples, a careful calibration and evaluation procedure can result in the estimated accuracy of 2-3% between 22 < Z < 30 and 5% between 11 < Z < 20. However, it should be kept in mind that the analytical accuracy in measurements performed on actual thin samples may be degraded by effects pertinent to the applied sampling technique. As described in Sect. 33.1.4.2 special care should be taken with regard to stopping, absorption, and matrix effects in thick sample cases. 

Because NIR is typically a low-resolution technique, the importance of accurate wavelengths or wavenumbers was not emphasized. The proposed USP method for wavelength accuracy defines three peaks with tolerances of 1 nm at 2000, 1600, 1200 nm. This translates to allowable errors of 5.0, 7.8, and 13.9 cm A typical FT-NIR spectrophotometer has a precision of better than 0.01 cm . In Figure 5.13, a three-week monitoring of the water-vapor peak at 7299 shows a standard deviation of 0.0027 cm (0.0005 nm). This precision has required careful evaluations of the standards that are used for NIR. 

Quantitative sorting results of the sequences are displayed in Fig. 22. The sorting accuracies defined by (65) are listed in Table 5 as a performance measure to compare the results. In those sequences, improved performance is observed by sorting the derivative of spikes rather the original waveforms. 

At each phase of a project cost information is required to enable decisions to be taken. In the conceptual phase these estimates may be very approximate (e.g. + 35% accuracy), reflecting the degree of uncertainty regarding both reservoir development and surface options. As the project becomes better defined the accuracy of estimates should improve. 

An experimental activity on the stress measurement of a pressure vessel using the SPATE technique was carried out. It was demontrated that this approach allows to define the distribution of stress level on the vessel surface with a quite good accuracy. The most significant advantage in using this technique rather than others is to provide a true fine map of stresses in a short time even if a preliminary meticolous calibration of the equipment has to be performed. 

The main sources of error which define the accuracy are counting statistics in tracer concentration measurements, the dispersion of the tracer cloud in the flare gas stream, and the stationarity of the flow during measurements. 

Since and depend only on die valence charge densities, they can be detennined once the valence pseudo- wavefiinctions are known. Because the pseudo-wavefiinctions are nodeless, the resulting pseudopotential is well defined despite the last temi in equation Al.3.78. Once the pseudopotential has been constructed from the atom, it can be transferred to the condensed matter system of interest. For example, the ionic pseudopotential defined by equation Al.3.78 from an atomistic calculation can be transferred to condensed matter phases without any significant loss of accuracy. 

Equilibrium constants for protein-small molecule association usually are easily measured with good accuracy it is normal for standard free energies to be known to within 0.5 kcal/mol. Standard conditions define temperature, pressure and unit concentration of each of the three reacting species. It is to be expected that the standard free energy difference depends on temperature, pressure and solvent composition AA°a also depends on an arbitrary choice of standard unit concentrations. 

Accuracy, however, in biomolecular trajectories, must be defined somewhat subjectively. In the absence of exact reference data (from experiment or from an analytical solution), the convention has been to measure accuracy with respect to reference trajectories by a Verlet-like integrator [18, 19] at a timestep of 1 or 0.5 fs (about one tenth or one twentieth the period, respectively, of the fastest period an 0-H or N-H stretch). As pointed out by Deufihard et al. [20], these values are still larger than those needed to... 

In order to compare the efficiency of the SISM with the standard LFV method, we compared computational performance for the same level of accuracy. To study the error accumulation and numerical stability we monitored the error in total energy, AE, defined as... 

Accuracy is defined here as relative to an infinitely periodic reference system. The values of the energies and forces in the reference system can be determined to... 

Any set of one-eleelrori ftinctions can be a basis set in the IjCAO approximation. However, a well-defined basis set will predict electron ic properties using fewer leriii s th an a poorly-defiri ed basis set. So, choosin g a proper basis set in ah inilio calculation s is critical to the rcliabililv and accuracy of the calculated results. 

For small molecules, the accuracy of solutions to the Schrtidinger equation competes with the accuracy of experimental results. However, these accurate a i initw calculations require enormous com putation an d are on ly suitable for the molecular system s with small or medium size. Ah initio calculations for very large molecules are beyond the realm of current computers, so HyperChern also supports sern i-em p irical quantum meclian ics m eth ods. Sem i-em pirical approximate solutions are appropriate and allow extensive cliem ical exploration, Th e in accuracy of the approxirn ation s made in semi-empirical methods is offset to a degree by recourse to experimental data in defining the parameters of the method. 

Handbook 44 defines five accuracy classes for scales in terms of the value of the scale division and the number of divisions. Class I appHes to precision laboratory weighing. Class II appHes to laboratory weighing (precious metals, gems, and grain test scales). Class III appHes to the majority of industrial and retail scales, and to all scales not specified in the other categories. Class III L appHes to vehicle, Hvestock, railway, crane, and hopper scales. Class nil appHes to portable scales used for highway weight enforcement. 

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