Steekproeven uit de halve cauchy verdeling

Summary Let x₁…, x_n be a sample from a distribution with infinite expectation, then for n→∞ the sample average x?_n tends to +∞ with probability 1 (see [4]). Sometimes x?_n contains high jumps due to large observations. In this paper we consider samples from the “absolute Cauchy” distribution. In practice, on may consider the logarithm of the observations as a sample from a normal distribution. So we found in our simulation. After rejecting the log-normality assumption, one will be tempted to regard the extreme observations as outliers. It is shown that the discarding of the outlying observations gives an underestimation of the expectation, variance and 99 percentile of the actual distribution.     

Inleiding over de verdeling van extremen

Summary This paper is an introduction to the exact and asymptotic distribution of univariate statistical extremes and gives the methods of estimation of the parameters of the double exponential distribution.     

Een steekproef ter vaststelling van de verdeling van de hoenderstapel

A sample estimate of the poultry distribution
In 1954 a sample survey was carried out of the returns of the agricultural census, May 1954, in order to establish the distribution of the number of holdings and the number of poultry, by size-group of arable land and by size-group of number of poultry. A simple 10 per cent, sample was planned and the expected variances of the numbers of poultry in each size-group were estimated beforehand. The method of estimation is indicated in this paper. This resulted in comparatively high relative errors in the size-groups above 500 hens and also in the size-groups of arable land. Therefore holdings with 500 hens and over were enumerated completely. Some tests were performed with the sample results and finally the efficiency of the stratification is discussed.     

Het voorspellen van levertijden uit gegevens over de voort-gang van een project

Estimation of dates of delivery by extrapolation of progress-data for a project.
The problem can be put in mathematical form with the aid of some assumptions with regard to the occurrence of interruptions.
The progress of the project is supposed to be interrupted by time-intervals during which progress is fully stopped. These intervals start at irregularly distributed moments and have a variable size. The points on the time axis corresponding with the moments of stagnation will show a constant average density, if a constant average production capacity or development capacity is available. This means that the results are valid only if no alterations are made which influence the general progress of the project involved.
The application of probability theory to problems connected with promises of delivery may, in general, look unacceptable.
Many projects, however, have an experimental character and unforeseen technical and organisational troubles are unavoidable.
In such cases the theory makes it possible to obtain a maximum amount of information contained in the progress-data and may help management to make the best decisions.     

Afleiding van kwartaalcijfers uit jaartotalen

Summary Quarterly figures may be required when only a sequence of annual totals is available. This article presents two reasonable methods for “interpolating” quarterly figures by means of appropriate minimizing procedures. The first method relates to minimizing the sum of squared second differences of the quarterly figures, the other one is a linear programming procedure which refers to the absolute second differences. Both methods are illustrated by a numerical example, the first one giving somewhat better results.     

Afleiding van kwartaalcijfers uit jaartotalen

Summary  Quarterly figures may be required when only a sequence of annual totals is available. This article presents two reasonable methods for "interpolating" quarterly figures by means of appropriate minimizing procedures.
The first method relates to minimizing the sum of squared second differences of the quarterly figures, the other one is a linear programming procedure which refers to the absolute second differences. Both methods are illustrated by a numerical example, the first one giving somewhat better results.     

Statistisch onderzoek van contrôle-analyse cijfers: (De verdeling van het droge stofgehalte van het brood tijdens de tweede wereldoorlog)

Summary  (Statistical investigation of the distribution of data for the solids of bread (in loaves analysed in the Food Inspection Laboratory in Amsterdam))
The distributions of the data of the solids of bread as analysed during the years of the war are investigated. The means and the standard deviations are calculated, also χ², kurtosis and skewness supposing the distributions to be normal. An example of calculation is given in table I. Actual numbers for different years are given in table II and in table III. The distributions were tested on normality because former investigations showed that the distribution of under survey prepared loaves did not deviate significantly from the normal.
It is found that generally the investigated distributions cannot be regarded as normal. Though symmetric they show leptokurtosis and the χ²-test for the goodness of fit of normal equation gives values of P 0,01 (or a little more). Similar distributions were found by Clancey¹⁾ in his investigation of numbers of chemical analyses of industrial products (about 10% of the distributions showed this shape, some 10% were truncated leptokurtic curves) and by us for the fat percentage of meals from the governmental eating-houses. The distributions are represented on probability-paper. This way of representing results gives a clear view of the variations of the mean and the standarddeviation in the course of the years (fig. 1). The deviations of the shape of the normal straight line on probability paper by special causes is investigated (fig. 3, fig. 4, fig. 5, fig. 6 to be compared with fig. 2). With this "spectrum" of possibilities of deviations from the normal distribution in mind the special cause for the leptokurtic shape in our special case has been discussed.     

Het vergelijken van twee verschillende schatters voor een percentiel P van een normale verdeling

A comparison is made between two different methods to estimate the probability that a normally distributed observation is less than a certain value. One method is based on the binomial distribution, the other one on HALD'S maximum likelihood estimates of the parameters of a censored normal distribution. For large sample sizes a graph of the relative efficiency of these two estimates is constructed. A sampling experiment was performed in order to investigate for one particular situation the possible bias of HALD'S maximum likelihood estimate, which is only asymptotically unbiassed.     

Simplified estimation of parameters in a cauchy distribution

Simplified estimators of the location and scale parameters of a Cauchy distribution are constructed along the lines developed by D ixon [3, 4]. Symmetrically censored samples are considered. The efficiency of these estimators is shown to be high enough to make them useful in practice.     

Toespraak door de directeur van de Stichting "Kwaliteitsdienst voor de Industrie"

Adress of the Director of the Foundation Industrial Quality Service.
The increasing of productivity also has an important qualitative aspect, To promote the qualitative increase of productivity the "Kwaliteitsdienst voor de Industrie" (Industrial Quality Service) wants to organize courses through which the statistical quality control methods can for each separate branch of industry be made available to those who are able to apply these methods, but who cannot spare the time and the energy required to take fully note of the mathematical and statistical backgrounds.     

Propuesta de indicadores SMARTER de trabajo decente para la agenda de desarrollo posterior a 2015

Los indicadores actuales de los ODM sobre empleo presentan deficiencias importantes, como problemas de medición, uso inadecuado de estadísticas agregadas, ambigüedad interpretativa y supuestos de base no aplicables a los países en desarrollo. Tratando de superar estos problemas, los autores proponen cuatro nuevos indicadores de empleo productivo y trabajo decente: el crecimiento de la contribución del trabajo al valor añadido por trabajador, la tasa de trabajadores pobres y los porcentajes de trabajadores que ganan menos de un ingreso laboral mínimo absoluto y relativo (el 60 por ciento de la mediana del ingreso laboral). Aplican empíricamente estos indicadores a los casos de Uganda y Perú.     

La igualdad de género y la gobernanza de las cadenas de valor mundiales. Promoción de los derechos de las trabajadoras

La gobernanza privada, canalizada por conducto de programas de cumplimiento social e iniciativas de las empresas multinacionales en favor de la igualdad de género, no basta por sí sola para poner coto a la discriminación por razón de género en las cadenas de valor mundiales (CVM). Los Principios Rectores de las Naciones Unidas sobre las empresas y los derechos humanos (en adelante, Principios Rectores) proporcionan un marco que conjuga la gobernanza pública y la gobernanza privada a fin de abordar los derechos humanos en su globalidad, con inclusión de la igualdad de género. En el presente artículo se analiza si tales principios pueden ofrecer un marco de gobernanza más eficaz para atender los derechos de las trabajadoras en las CVM. Se sostiene que para poner fin a la discriminación por razón de género en las CVM y promover el ejercicio de la debida diligencia en materia de derechos humanos con una perspectiva de género es indispensable recurrir a una gobernanza en la que se articulen, en colaboración sinérgica, las entidades públicas, privadas y sociales.     

Oneindige verwachting en de wet van de grote aantallen

De beide wetten van de grote aantallen (de zwakke en de sterke) vormen een centraal punt van de kansrekening. In het onderstaande wordt op eenvoudige wijze aangetoond, dat zij ook gelden voor steekproeven uit verdelingen met oneindige verwachting. Een minder eenvoudig bewijs is te vinden in M. LOÈVE, Probability Theory, Princeton 1963.
Dehiergebruikte bewijsmethode werddeschrijver aanbevolen door dr. J. FABIUS.     

Incumplimiento de la Ley de fábricas de la India. Alcance y pautas

Existen pocos datos sistemáticos sobre el alcance del incumplimiento de la legislación en los países en desarrollo, que se cree generalizado. Con datos de dos encuestas de empresas, los autores cuantifican el incumplimiento de la Ley de fábricas de la India y observan que las empresas infractoras doblan a las conformes y superan con mucho a las que eluden la ley mediante ciertos ajustes. Analizan las principales tendencias y pautas de incumplimiento y las ponen en relación con la ausencia de empresas de tamaño medio en la India y los debates sobre reglamentación. También destacan cuestiones para investigaciones futuras.