ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1949.tb00379.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

SummaryStatistical experiences in 1948.A great difficulty in the execution of our building programme is caused by the continual changes in the prices of building materials, and by the financial risks occasioned thereby.Since complete discounting of these risks for each finished building separately would require an enormous administration, a statistical solution of the problem has been sought. The risks are computed not for the buildings themselves, but for “equivalent” buildings composed of suitably chosen, standardized component parts and building elements. This procedure, which has been found sufficiently accurate and has been adopted by the Dutch government, is described in outline. Details have been published elsewh

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1949.tb00380.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

SummaryStatistical research in the science of insurance.This article brings a survey of some of the statistical problems, solved or unsolved, encountered in the science of insurance. Whereas life insurance rests on a fairly sound basis, the foundations of fire insurance still involve some speculative arguments, owing to lack of data and to the irregular influence of meteorological and economic factors. The insurance against hospital costs has to take into account the fact that the length of stay in hospital is not independent of the amount insured. These various problems are briefly discussed.

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1949.tb00381.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

SummaryNoise in radio valves as a statistical phenomenon.If an electric current is interpreted as. the passage of a certain number of electrons per second, it is evident that such a current will be subject to statistical fluctuations. These fluctuations, commonly designated as “noise”, limit the maximum amplification applicable in radio reception. Some of the fundamental principles of noise formation are treated in this article from a statistical point of view. The formation of noise, noise suppression by space charge, current‐distribution noise, and noise due to secondary emission are successively disc

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1949.tb00382.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

SummaryA statistical method for the detection of immunity by means of the rabbit skin test.This paper discusses the statistical basis of a technique that has already, without detailed explanation, been applied in a previous paper by Dr Winsser (1).5 plots, arranged in 5 rows (25 plots in all) laid across the skin of a rabbits back, are injected with infectious matter in amounts inc easing in geometric progression. To four of these rows sera prepared from four different test persons are added; and the immunity is judged by the resulting decline in skin reaction as compared with the row, mostly situated at the caudal end, which serves as control.Since at the lowest concentrations of infectious matter the skin reactions were altogether too weak to show any marked decline, these were ignored. The sum, y, for each serum of the reaction values at the remaining four concentrations is compared with the corresponding sum, yk, for the control, and for the difference (yk‐y), 5 % and 1 % levels of significance are determined.To determine these limits, variations in sensibility between animals and over the area of skin of each individual had to be taken into account. This was done by analysing the skin reactions of 5 animals infected without serum; the use of more animals being considered too costly. The results show significant differences between individual means, insignificant differences between individual regressions along the back, and a significant common regression. In calculating the 5% and 1% percent limits it was assumed that the residuals with respect to individual regression lines are normally distributed, which they clearly are not; and that the individual regressions are equal, which, despite the insignificance observed, is probably not correct. To atone for these deficiencies the limits imposed were more severe than those commonly adopted. Some of the criticisms that may be directed against this procedure are recognized and discusse

ISSN:0039-0402    

DOI:10.1111/j.1467-9574.1949.tb00383.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY