Randomness test

Stich-kultur, /. stab culture, -loch, n. tap hole, -pfropf, m. tap-hole plug, -probe, /. sample at random sample taken by tapping or piercing random test, spot check (Metal.) assay of tapped metal (Brewing) pricking teat. 

Van der Voet [21] advocates the use of a randomization test (cf. Section 12.3) to choose among different models. Under the hypothesis of equivalent prediction performance of two models, A and B, the errors obtained with these two models come from one and the same distribution. It is then allowed to exchange the observed errors, and c,b, for the ith sample that are associated with the two models. In the randomization test this is actually done in half of the cases. For each object i the two residuals are swapped or not, each with a probability 0.5. Thus, for all objects in the calibration set about half will retain the original residuals, for the other half they are exchanged. One now computes the error sum of squares for each of the two sets of residuals, and from that the ratio F = SSE/JSSE. Repeating the process some 100-2(K) times yields a distribution of such F-ratios, which serves as a reference distribution for the actually observed F-ratio. When for instance the observed ratio lies in the extreme higher tail of the simulated distribution one may... 

H. van der Voet, Comparing the predictive accuracy of models using a simple randomization test. Chemom. Intell. Lab. Syst., 25 (1994) 313-323. 

The objective with the certification is to ensure that the certified products present no danger to human health to the best current knowledge. Furthermore, the product undergoes testing and will continue to undergo random tests after the mark is issued. 

The samples (minimum four batches) included in the study should cover the expected normal variation of the process (target 3 sigma). If the batches used do not represent the full and normal process variation, the calculations are based on a historical value for process variation. The same batches are analyzed by multiple analysts (minimum 2) in different laboratories (minimum 3) using their own instruments, reagents, and solvents. Each analyst performs the entire method as described. Every sample should be analyzed at least twice (with independent sample preparation) in the same run. The replicates should also be blinded and randomly tested. 

Dejaegher, B., Capron, X., Smeyers-Verbeke, J., and Vander Heyden, Y. (2006). Randomization tests to identify significant effects in experimental designs for robustness testing. Anal. Chim. Acta 564, 184-200. 

A widely used approach to establish model robustness is the randomization of response [25] (i.e., in our case of activities). It consists of repeating the calculation procedure with randomized activities and subsequent probability assessments of the resultant statistics. Frequently, it is used along with the cross validation. Sometimes, models based on the randomized data have high q values, which can be explained by a chance correlation or structural redundancy [26]. If all QSAR models obtained in the Y-randomization test have relatively high values for both and LOO (f, it implies that an acceptable QSAR model cannot be obtained for the given dataset by the current modeling method. 

Bestatin has been st ]died clinically during the last 6 years. Dally oral administration of 30 or 60 mg to cauicer patients restored the lowered immunity indices in stx h patients (64). Clinical randomization tests for the therapeutic effects of bestatin have been conducted. For instance, the survival period of patients with melanoma after the macroscopic elimination of tumors by surgery emd chemotherapy has been significantly prolonged by bestatin administration (30 mg, dally, orally) compared with the cases of controls without stich bestatin treatment. 

State laws regulating workplace drug testing vary. Some states ban or limit the use of random tests without individual suspicion. Some states also provide for some form of appeals process or retesting for employees found to test positive. 

From Table 2.3, C3 cre = Cf, so for this random test the multiplication of two matrix representations again gives the same result as the group multiplication table. 

In September 2001, the National Football League (NFL) joined the National College Athletic Association (NCAA) and the International Olympic Committee (IOC) and banned its players from using ephedrine. The ephedrine ban means that NFL players can be randomly tested throughout the year for ephedrine use. 

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