Reliability statistics

R. Dovich, Reliability Statistics, ASQC Quality Press, Milwaukee, Wis., 1990. 

Once tlie system components and their failure modes have been identified, tlie acceptability of risks taken as a result of such failures must be determined. Tlie risk assessment process yields more comprehensive and better results when reliable statistical and probability data are available. In tlie absence of such data, tlie results are a strong function of tlie engineering judgment of tlie design team. The important issue is tliat both tlie severity and probability (frequency) of the accident must be taken into account. 

With respect to sampling, sufficient numbers of environmental samples should be obtained to permit reliable statistical and biologic Interpretation of results. At the same time, the samples collected should be from environmental locations where human exposure Is most likely to occur (or did occur. If questions of past exposures require assessment). They should also be targeted for those environmental media which can be expected to have the greatest potential for human exposure and absorption. Finally, the samples must be obtained and preserved so that the chemicals which pose the greatest threat for human health In terms of toxicity and tissue persistence can be accurately measured. 

On the other hand, the prediction by content approach is applicable regardless of the variety of sorting pathways. It may be applied to partial sequences, which are now massively produced day by day. In addition, this approach allows a simple and unified treatment, which is convenient for objective testing (e.g., cross validation). However, there is no guarantee that the amino acid composition of proteins in each localization site is well conserved. Even when a clear tendency is observed for a known set of proteins, it can be an artifact resulting from the deviation of data because the size of known proteins for each site is often insufficient to perform reliable statistical analyses. It is also evident that this approach cannot handle the differences among isoforms with different localization (see Section III,K,3). 

Reliable statistical calculation of the data is performed by the cytometer s software, resulting in a simple evaluation of the association assays performed to characterize the interaction between targeted systems and the cells. The individual cell populations are usually described by the relative mean, either arithmetic or geometric, and the coefficient of variation of a particular parameter, as well as the number of cells within the respective population. 

We have chosen animal cell cultures for that purpose, bearing in mind the following advantages of such system (i) the action of peptide results in a limited number of integral responses, when a variety of biochemical mechanisms gives rise to uniform effects, such as cell death or stimulation/inhibition of cell proliferation rate (ii) the test requires low, picomolar amounts of peptides (iii) the results are treated by simple and reliable statistic methods. 

In comparisons of eqnilibrium constants collected from the literature (e.g.. Fig. 4.22 or [47]), or correlations of data for a large number of systems (e.g.. Figs. 4.20-4.23), it is desirable to present both the statistical uncertainty of each point which is often given by the standard deviation (one or several a s) of the point, and the general reliability (statistical significance) of the whole correlation [76], for which the chi-square test offers a deeper insight into the reliability of the experimental results [77]. More advanced statistical tests for systems of our kind have been described by Ekberg [78]. 

From equations 13 16, the standard error for each measurement as a function of the elution time can be obtained. Additional propagation of these errors through the Integration across the chromatogram results in estimates of the errors associated with the SEC calculation of the average polymer properties. Therefore, it enables reliable statistical comparisons between SEC estimates and static measurements... 

Closely related to the striking uniformity of inner-city heroin prices at retail level in the United States is the gigantic discrepancy between known levels of opium production for illegal purposes and consumption by the world s addict population. Fairly reliable statistical data are available for both. Within great margins of fluctuation depending on weather, enforcement, and other conditions, available supply exceeds demand by roughly a factor often. 

A large amount of e-waste is flowing into Asian countries mainly from developed countries and a substantial part of the e-waste is not appropriately treated. There is no reliable statistics available on how much e-waste is flowing into Asia or circulating within Asia for inappropriate recycling operations however, it seems that at least a part of exported electric appliances are coming back to their birth places after their product lives end. 

The whole procedure, with or without salts, may not be based upon sound statistical principles. Rather than using various object functions, it appears better to use a reliable statistical technique such as the method of maximum likelihood (24) or the Bayesian approach (25), both of which take into account the errors in all experimental observations in a logically justifiable fashion. The various discrepancies and anomalies noted in the present work would be moderated by using either... 

QSRR are derived statistically. To get reliable statistics one needs a large amount of appropriate data. The great advantage of QSRR analysis over other quantitative structure-property relationship studies is that chromatography can readily produce a laige amount of relatively precise and reproducible data. In addition, in a chromatographic process all conditions may be kept constant and hence the structure of the analyte becomes the single independent variable in the system [12],... 

Longer simulations or a series of shorter simulations will give a more reliable sampling of the phase space. Especially conformational phase spaces of flexible molecules. Also longer simulations are needed to get reliable statistics for dynamical phenomena with long time constants. 

The use of these two measures is very scarce in secondary structure prediction literature, despite their obvious superiority over Q3. In one of the few publications that utilize Mathews correlation coefficients, Holley and Karplus (1989) reported values of Ca=41%, Cp=32% and Cc=36%. In the new analysis those values were sensibly decreased (Ca=32%, Cp=25% and Cc=31%), clearly indicating there is a poor generalization power of the method to a larger set of proteins. It also strengthens an important fact for secondary structure evaluation, already noted by Rost and Sander (1994), which is the need of a representative testing set in terms of size and structural composition that permits gathering reliable statistical information from the results. 

Kinetics of nucleation may be studied by microscopic examinations of surfaces from which numbers of growth nuclei/unit area (N) are counted after known reaction times. Photographs of the surface may be taken at appropriate intervals and used to obtain the quantitative information. The nucleation law is sometimes also inferred from the overall kinetic behaviour. Precise fits to rate laws (including nucleation) require large numbers of accurate observations to enable reliable statistical analyses of the data to be made and it is frequently difficult to obtain sufficient numbers of reliable (N,t) values. The rate equations in Table 3.1. represent, to an acceptable approximation, all types of behaviour that can realistically be expected [10]. 

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