Error factor

The described method can generate a first-order backward or a first-order forward difference scheme depending whether 0 = 0 or 0 = 1 is used. For 9 = 0.5, the method yields a second order accurate central difference scheme, however, other considerations such as the stability of numerical calculations should be taken into account. Stability analysis for this class of time stepping methods can only be carried out for simple cases where the coefficient matrix in Equation (2.106) is symmetric and positive-definite (i.e. self-adjoint problems Zienkiewicz and Taylor, 1994). Obviously, this will not be the case in most types of engineering flow problems. In practice, therefore, selection of appropriate values of 6 and time increment At is usually based on trial and error. Factors such as the nature of non-linearity of physical parameters and the type of elements used in the spatial discretization usually influence the selection of the values of 0 and At in a problem. 

The error factor (EF) defined as equation 2.5-16 relates the 50th percentile to the 95th percentile (equation 2.5-17) and the 5th percentile (equatin 2.5-18). 

Since dependency analysis is not needed, we can go on to the BUILD program. Go to FTAPSUIT and select 5 "Run Build." It asks you for the input file name including extender. Type "pv.pch," It asks you for name and extender of the input file for IMPORTANCE. Type, for examle, "pv.ii . It next asks for the input option. Type "5" for ba.sic event failure probabilities. This means that any failure rates must be multiplied by their mission times as shown in Table 7.4-1. (FTAPlus was written only for option 5 which uses probabilities and error factors. Other options will require hand editing of the pvn.ii file. The switch 1 is for failure rate and repair time, switch 2 is failure rate, 0 repair time, switch 3 is proportional hazard rate and 0 repair time, and switch 4 is mean time to failure and repair time.)... 

OPTION 5 BASIC EVENT PROBABiLtriES AND ERROR FACTORS RIRNBAUM (NO). CRITICALITY (NO), UPGRADING FUNCTION (NO) FUSSELL-VESELY (YES), INITIATOR (BARLOW PROSCHAN)(N0), ENABLER (CONTRIBUTORY) (NO). STRUCTURAL (NO)... 

The mean core damage frequency from all internal events is 1.8E-4/yr, with an error factor (95% percentile divided by the median) of 5.0. The percentage contributions to the core dai e frequencies are Large Reactivity Insertion 28% Large LOCA, 28% Reactivity Insertion L P ramp, 12% Spurious/normal shutdown, 11% Loss of commercial power, 10% and others, 5 ... 

Number and type of record The number of data points or tables of data presented in the resource or the number of events the data set reflects where available, the form in which the data are presented, such as failure rates or availability data, confidence intervals or error factors the raw data source used, sueh as surveys, plant records, tests, or judgment. 

Estimates of hourly and per demand lailure rates for 20 categories with error factors generated by experts... 

Data Summaries of Licensee Event Reports at U.S. Commercial Nuclear Power Plants (Vanous Components) Nuclear 11209 one-fine event descriptions on specific component types failure rates and error factors Pumps, valves, diesels inverters, relays, circuit breakers (in separate reports) 100. 

NFAIL DEMAND ENP TIME UNIT MEAN MEDIAN STH 95TH ERROR FACTOR... 

Error factor The ratio of the 95th percentile value to the median value of a lognormal distribution. 

For air at room temperature, the error in this equation is less than 1 per cent for pressures as high as 400 psia. For air at one atmosphere of pressure, the error is less than 1 per cent for temperatures as low as —200°F. These error factors will vary for different gases. 

Active matter (anionic surfactant) in AOS consists of alkene- and hydroxy-alkanemonosulfonates, as well as small amounts of disulfonates. Active matter (AM) content is usually expressed as milliequivalents per 100 grams, or as weight percent. Three methods are available for the determination of AM in AOS calculation by difference, the two-phase titration such as methylene blue-active substances (MBAS) and by potentiometric titration with cationic. The calculation method has a number of inherent error factors. The two-phase titration methods may not be completely quantitative and can yield values differing by several percent from those obtained from the total sulfur content. These methods employ trichloromethane, the effects from which the analyst must be protected. The best method for routine use is probably the potentiometric titration method but this requires the availability of more expensive equipment. 

This should come as no surprise, since the physical behavior of materials is non-linear and unpredictable, especially when materials are formulated or in combination. Two examples will suffice high temperature ceramic superconductors and insulators above their critical temperatures or at non-ideal stoichiometries composite structures may show several times the strength or impact resistance than would be expected from their component materials. Materials discovery will always require a good deal of trial and error, factors that may be mitigated by techniques that permit the simultaneous synthesis of large numbers of materials, followed by rapid or parallel screening for desired properties. 

If open sampling is provided, the sampling point should be located where adequate dispersion of released vapors will occur. The sampling point should be located so it is easily accessible so human error factors are reduced. 

NIOSH states that acceptable air monitoring methods must come within 25% of the true concentration for 95% of the samples taken. The error factor attributed to sampling pumps is a coefficient of variation of 5% ( 2). If there is no bias in the sampling pump, the accuracy is ... 

Trace element concentrations are obtained in the semi-quantitative mode by ICP-MS, LA-ICP-MS, SSMS or SNMS with an error factor of about 0.3-3 for most elements. The results of semi-quantitative trace analysis, e.g., for high purity materials, are sometimes sufficient to estimate the purity of the matrix investigated. 

In order to maintain a constant error factor inside and outside pad pairs were analyzed on the same day. Blank analyses were run on each lot of solvent and pads to insure there were no interfering peaks. Each blank was concentrated from 50 ml to 1 ml prior to injection, thus insuring that the field samples which needed concentrating would be free of interfering peaks in the ethion position. No such peaks were found in any of the blanks. 

After having studied the method above systematically, NRCCRM established a practical analysis procedure which could control the error factors effectively at the same time. 

Uncompensated resistance — A modern 3-electrode potentiostat compensates for the solution resistance between the counter and reference electrodes, but not for the solution resistance between the reference electrode and the working electrode. Such resistance is referred to as the uncompensated resistance (Ru). The resistance of the working electrode itself also contributes to the uncompensated resistance (but is almost always negligible with metal electrodes). The voltage drop across Ru due to a current flow is IRU and results in a potential control error. Factors that influence Ru (and thus IRU) include conductivity of the electrolyte, shape and size of the cell, the location of the reference electrode, the shape of the working electrode, and the size and position of the counter electrode [i,ii]. Ru can be lowered by addition of supporting electrolyte... 

Step 6. Having identified such structural factors (the real root causes), the model must allow interpretation of these, i.e. it must suggest ways of influencing these factors, to eliminate or diminish error factors and to promote or introduce recovery opportunities in the human-machine systems and indeed in the organisation as a whole. 

The presence or absence of a fourth band represents a margin-of-error factor (commonly called the resistor s tolerance range). 

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