bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistiek, Operationele Research en Computer*
Authors: Wiggers B. G. 
Published: April 2008

SummaryThe computer, which has penetrated practically all sectors of human activity, has also influenced the fields of statistics and operational research.In this lecture a bird's eye view is given, in which the lectures held in the different sections are quoted as detailed examples.In the first place the attention is drawn to the use of the computer for the computational and clerical work, inherent to well‐known statistical techniques such as computation of estimates of parameters from samples, analysis of variance, regression and correlation analysis, factor analysis and the analysis of time series.Another group of application relates to the processing of large amounts of data, with or without application of more advanced statistical methods, e.q. processing of survey data, processing and analysis of large amounts of laboratory data or quality control data in a plant. Special attention is paid to the rôle of the computer in promoting the cooperation between quality control experts and control engineers, both of which are active in the process‐control field. The computer plays an analogous role with respect to OR experts and control engineers, because of the common interest in optimization techniques.Further, the computer has played an important role in the application of OR methods and techniques. Special mention should be made of linear programming and of the use of simulation methods, in which both statisticians and OR‐analists are involved.The development of “management information systems” is mentioned, a close cooperation between administrative experts and statisticians andjor OR‐analists being urged upon.On the other hand statistics and operational research in their turn serve the computer, e.q. in the design of efficient coding systems and maintenance systems.Further, inside the computer there are many complicated priority and queueing problems, because of the enormous amount of data transported.Finally the important contribution is mentioned, which statistics and OR can make towards the efficient use of computers.
Enkele facetten van numerieke weersverwachtingen*
Authors: Heijna B. 
Published: April 2008

SummaryThe numerical prediction of weather is a subject which is still in an early stage of rapid growth. Although it has already reached a degree of reliability, comparable with the conventional method of prediction, there still remain a number of problems to be resolved.These problems are partly of meteorological, partly of mathematical and partly of statistical nature. Some of them are discussed in this article.
Ervaringen met toepassing van computer programma's bij het sociologisch onderzoek aan het Centraal Bureau voor de Statistiek*
Authors: Wit J. W. W. A. 
Published: April 2008

SummaryThe Central Bureau of Statistics uses ‐ next to their conventional punchcard machines ‐ since 1960 a computer. This computer processes millions ofpunchcards for several monthly and yearly censuses. The influence of the use of this on the work at the Bureau is briefly discussed. Only a very small percentage of time it is used for econometrical work and other statistical research. An analysis of the savings‐habits of dutch families is given as an example of a small research‐job.
Levensduur en sloop van personenauto's in Nederland, 1950–1964*
Authors: Cramer J. S. 
Published: April 2008

SummaryThe life distribution of motorcars is examined over the period from 1950 to 1964. Age‐specific survival rates, derived from Dutch registrations, are averaged and lead to the life table shown in table 4. The deviations from average age‐specific survival rates show no significant variation over time nor over successive car generations. Since the registrations include an increasing number of used cars imported from Germany this apparent stability hides compensating changes in car scrap page.Since before the war the life expectancy of motorcars has increased from 8 to 11 years, and it is argued that this is due to the widening of the used car market. In the next stage, which is already well under way in Germany, new cars replace used cars, and rising apparent scrappage rates reflect the disposal of the latter by export.
De gemiddelde bezetting van personenauto's in interlokaal verkeer*
Authors: Geerllngs J. W. H. 
Published: April 2008

SummaryThis paper, read in Utrecht on October 14th 1965, deals with the average occupancy of cars outside urban areas. During the years 1962 and 1963 more than 500 samples (each consisting of 150 cars) have been taken on two points of the dutch road‐system. The samples covered the different months, days (sundays, Saturdays and week‐days) and hours (except those without daylight).The average occupancy turned out to be 1.8 on week‐days (with a minimum of 1.4), 2.5 on Saturdays (with a minimum of 2.1) and 3.1 on Sundays (the over‐all average for all days being 2.1). These results seem to be representative for the whole dutch car traffic as is shown by comparison with observations on other points and other data.Comparison of the seasonal, weekly and hourly patterns of the average occupancy with those of the car traffic density enable to draw conclusions about the responsibility of different kinds of traffic (commercial and commuter traffic versus social traffic) for congestion and for the construction and maintenance cost of the road‐system.
Sturen met Statistiek*
Authors: Tinbergen J. 
Published: April 2008

SummaryThis lecture deals with a general view on forecasting and planning with special emphasis on the application in less developed countries.After some introductory remarks attention is paid to the evaluation of the results of forecasting by means of statistical methods in comparing forecasts and realization.The paper gives some outlook on the general features of planning in the less developed countries. Special attention is drawn to a rather new aspect of the matter: the importance of non‐economic factors which may have great influence on the process of development. Thorough investigation in this field seems necessary as it may contribute to a better planning and to more efficient activities in these countries.
Automatische Marktregulering*
Authors: Hamming G. 
Published: April 2008

SummaryAutomatic market regulation.The free market system can be considered as a cybernetic process. Due to time lags between decisions and realisation this type of process can generate cycles (Cobweb theorem).It is often tried to puts limits to desastrous price fluctuations be means of international product agreements. It cannot be claimed, however, that these agreements are satisfactory. The author's opinion is that the main difficulty is caused by the fact that the governments do not negociate on a working cybernetic process but on price limits.The author shows the possibility to smooth price fluctuations by means of buffer stocks. Selling and buying are exactly defined by given formulae. The system allows the market to find its equilibrium price; this essential task of a market mechanism is not affected by the buffer system.A system has been given in detail for the pork market. The consumer's price has to be increased by some 0,7 % in order to compensate the costs of reducing the price fluctuations to about 60 % of the original value. This example has only illustrative value.
Underlining random variables*
Authors: Hemelrijk J. 
Published: April 2008

SummaryThis paper gives an exposition of the convention, introduced by D. VAN DANTZIG in of indicating randomness by underlining the relevant symbols. This method of distinguishing between random variables (or elements) and non‐random ones serves a multiple purpose. It saves symbols and may be applied to symbols which have been introduced first in a non‐random quality. It clearly marks the line between measure theory and probability theory and, in statistics, between descriptive and stochastic models. This underlining notation has proved to be very useful during its nearly twenty years of use in Holland and many Dutch authors use it in their publications. The present description of the rules of this convention is meant to facilitate the reading of these papers and to deepen the understanding of the merits of this notation.
Network planning with stochastic activity durations, an evaluation of PERT
Authors: Lootsma F.A. 
Published: April 2008

SummaryThis paper deals with an examination of the well‐known Project Evaluation and Review Technique (PERT). Every activity duration is supposed to have a gamma distribution whose parameter values are determined from the optimistic, the most likely, and the pessimistic estimate of the duration. The expectation and the variance of the earliest event times are computed according to a method given by CHARLES E. CLARK in reference 2.One can then estimate the risk that a PERT planning, which is essentially a planning according to the critical path method, will be infeasible.During the examination it was found that errors in the pessimistic estimates may have serious consequences.
Estimation of the distribution of diameters of spherical particles from a given grouped distribution of diameters of observed circles formed by a plane section
Authors: Meisner J. 
Published: April 2008

SummaryA procedure is derived for estimating the distribution of diameters of spherical particles embedded in an opaque solid from a given grouped distribution of diameters of observed circles formed by their intersection with a random plane. The precision of the estimates can be characterized by the dispersion matrix of the joint estimates, which in its turn can also be estimated. Some numerical examples are given as well, one of them concerning the distribution of second‐phase spheroids in a sample of a high‐impact polystyrene.
Experimental determination of the power functions of the two‐sample rank tests of WILCOXON, VAN DER WAERDEN and TERRY by Monte Carlo techniques
Authors: van der Laan P. , Oosterhoff J. 
Published: April 2008

SummaryIn this paper the authors present the results of a sampling experiment to determine the power functions of the two‐sample rank tests of WILCOXON, VAN DER WAERDEN and TERRY against shift alternatives for normal parent distributions, based on 2000 trials for each alternative. The sample sizes considered are m = n = 6 and m = n = 10. The powers of the three rank tests are compared with the power of the STUDENT t‐test and with each other. The results indicate that in small samples (i) the power of the WILCOXON test is not much smaller than the power of the t‐test and (ii) the normal scores tests are only slightly superior to the WILCOXON test, if at all.
Vergelijking van voorspelling en realisatie als bijdrage tot economisch bestuur*
Authors: van den Beld C. A. 
Published: April 2008

SummaryA rather long time has elapsed since the predictions of the Central Planning Bureau were considered critically. It therefore seemed highly desirable to make a new study on forecasts and realization. The present article summarizes very briefly some conclusions from such a study.An important statistic in this context is the inequality coefficient, which presents a numerical measure of predictive accuracy. It is easily derived from the difference between forecast and realization and it may refer to one variable, to a group of variables or to each annual Central Economic Plan as a whole. It enables to draw valuable conclusions about the predictive work done by the Bureau in the past. Generally a satisfactory progress in the results is found, but on the other hand there remain some weak points which need improvement. Given the limited scope of this lecture reference may be made to the more elaborate study of the whole problem, published in Monograph No. 10 of the Central Planning Bureau, entitled: “Forecasts and realization. The forecasts by the Netherlands Central Planning Bureau, 1953–1963”.
Uitgedund en gerekt Poissonproces.
Authors: Vervaat W. 
Published: April 2008

Summary.This paper generalizes an interrupted Poisson process first studied by ZAAT [8] and later by RUNNENBURG and VERVAAT [7]. The process is obtained by combining two independent stochastic processes on the non‐negative real axis. The first of these processes is a stationary Poisson process with intensity Λ and the second an alternating renewal process [1] dividing the axis in a‐ and b‐intervals alternatively. By omitting those points of the stationary Poisson process that fall in b‐intervals we create a new point process that we prefer to call a “thinned Poisson process”. The alternating renewal process is determined by the distribution functions A and B of the lengths of the a‐ and b‐intervals which are not the first interval to the right ofO and by an “initial distribution” (p, A0, B0), where p is the probability of starting with an a‐interval in 0, A0 the distribution function of the length of the first a‐interval provided that we begin with an a‐interval in 0, and B0 the distribution function of the first b‐interval provided that we begin with a b‐interval in 0.It is here shown that there always exist initial distributions for which the distribution function of the length of an interval between two successive points in the thinned Poisson process is the same for all intervals, and the class of initial distributions with this property is obtained. The common distribution function G of these lenghts has Laplace‐Stieltjes transform G as given in (3.15); it turns out that G depends on A, B and Λ only.For any initial distribution the distribution function of the distance between the nth and the (n + l)st point to the right ofO in the thinned Poisson process tends to the distribution function G as n tends to infinity. Finally the covariance of two successive distances between three successive points in the thinned Poisson process is studied. Some examples are given in which both positive and negative correlations occur.
How to poison Poisson (when approximating binomial tails)*
Authors: Molenaar W. 
Published: April 2008

Summary In these days some sportsmen are given dangerous drugs in order to stimulate them into still higher efforts. The present paper wants to add some poison to the classical approximation of a binomial by a Poisson distribution. The relatively harmless drug of a little extra calculation shall be seen to result in a much better accuracy.This paper reports both on theoretical considerations, following from series expansions of Poisson‐type parameters, and on extensive numerical investigations of accuracy by means of an Electrologica X8 computer. The main conclusion is that the probability of at most k successes in n Bernoulli trials with success probability p <.5 can be very closely approximated by the probability of at most k events in a Poisson distribution with expectation not np but (12–2p)n‐7kζ= (12–8p)n‐k+k/nnp.In the case p > 5 one should make p < .5 by a reversal, i.e. the interchanging of successes and failures, before the application of a Poisson‐type approximation (with one exception mentioned in section 4). For the probability of at least j successes one should approximate the complementary probability of at most j—1 successes.After an introductory section 1 and a discussion of measures of accuracy in section 2, the existing Poisson‐type approximations are treated in section 3. The fourth section introduces a new parameter and discusses the advantages of reversal in other situations than p > 5. In section 5 a series expansion for the exact Poisson parameter is derived. Two new parameters, among which is ζ, are introduced in section 6, where the series expansions for parameters given in table 4 lead to conclusions about the various approximations, summarized in table 6. The final section 7 gives some numerical results, which confirm to a large extent the conclusions from the asymptotic expansions.
De ontwikkeling van de inkomensongelijkheid gemeten volgens informatietheoretische maatstaven
Authors: Massizzo A. I. V. , Kok W. , Lisman J. H. C. 
Published: April 2008

Summary Some years ago Theil introduced new inequality measures, originating from information theory. He applied them 8.0. to income distributions in the United States.This inequality coefficient is ‐ in contrast to Pareto's constant ‐ based on the whole income distribution. Moreover, the inequality can be disaggregated into inequalities for groups of population.The numerical value of the inequality depends on the chosen class intervals; this may be inconvenient when making comparisons between countries, between different periods and the like. Hence we suggest an appropriate standardizing procedure.The inequality of income distributions has been calculated for the period 1950–1964 and a cornparison is made with Pmm's constant. The investigation relates to three groups of population: wage earners, self employed and others. A remark is made about between‐province inequalities.
Toepassing van Kosten's lotingsas in sirnulaties
Authors: Boer J. de 
Published: April 2008

SummaryA method known as Kosten's roulette model, for production of arrivals and departures in a simulated system, is described. This method seem to be not very well known outside the field of telecommunications. Some generalizations and restrictions of the method are described. Its advantages and disadvantages, compared with the ordinary method using a time axis, are outlined.
Stemmingen zonder winnaar
Authors: Zwet W. R. van 
Published: April 2008

Summary A group of n persons has to decide on one out of k alternatives. To achieve this end each pair of alternatives is put to a vote. It is assumed that each person ranks the k alternatives according to an individual preference scale and that on every vote between two alternatives he will vote for the alternative that occurs higher on his scale. If n is odd and an alternative obtains a majority on each of the (k ‐ 1) occasions on which it is put to a vote, the group will decide on that alternative. If no such winning alternative exists, a paradox of voting is said to occur. For even values of n the definition of a paradox is slightly more complicated.On the assumption that the preference scales of the n persons are obtained by n independent random drawings from the k! permutations of the numbers 1, 2,…,k, we discuss the computation of the probability of a paradox of voting Pk,n. Values of P3,n and Pk= lim Pk,n are given.
Raised conditional level of significance for the 2 × 2‐table when testing the equality of two probabilities
Authors: Boschloo R. D. 
Published: April 2008

SummaryIn this paper it is to be shown that Fisher's non‐randomizing exact test for 2 × 2‐tables, which is a conditional test, can by simple means be changed into an unconditional test using raised levels of significance; not seldom, especially for not too large samples, the level of significance can be doubled. This leads in many cases to a considerable increase of power of the test. A table with raised levels has been prepared up to sample sizes of 50 and a rule of thumb, which can be used if this table is not available, has been developEd.
Boekbespreking
Authors: Holtzer J. P. A. 
Published: April 2008

Book reviewed in this article: Combination of One‐sided Statistical Tests, J. Oosterhoff. Probability Models with Business Applications, R. C. Shook, H. J. Highland and E. H. Highland. Handbook of Nonparametric Statistics, III (Analysis of Variance) by Jonh E. Walsh. Mathematik für Mediziner und Biologen, G. Fuchs. Nonparametric Statistics, J. Hájek. Sampling Inspection and Quality Control, G. B. Wetherill.
An application of Pitman‐efficiency to acceptance sampling procedures*
Authors: Wouters J. , Zuylen M. C. A. van 
Published: April 2008

SummaryAs an exercise the concept of Pitman‐efficiency has been applied to the decision problem whether to use acceptance sampling “by attributes” or “by variables”.The Pitman‐efficiency has been calculated in the two cases that the variance of the underlying normal distribution is known and that it is unknown. Rather surprisingly the difference between these two cases proves to be considerable, even asymptotically. The asymptotic result is compared with the exact values of the relative efficiency in the case that s̀ is unknown. The asymptotic approximation appears to be rather good. The results derived also help to determine a suitable choice of the null hypothesis in order to increase the Pitman‐efficiency.
Principal components, analysis of variance and data structure
Authors: Mandel John 
Published: April 2008

AbstractThe relation between principal components and analysis of variance is examined. It is shown that the model underlying the extended analysis of variance developed by Gollob and Mandel is useful also as a model for principal component analysis. The elucidation of structure of two‐factor data using the new analysis of variance model is illustrated by an example taken from thermodynamics.
Exact distribution of Durbin's distribution‐free test statistic for Balanced Incomplete Block Designs, and comparison with the Chi‐square and F approximation
Authors: Laan P. van der , Prakken J. 
Published: April 2008

SummaryDurbin's distribution‐free rank test can be used to test the null hypothesis that there are no differences among the treatments in a Balanced Incomplete Block Design. Until now only the chi‐square and F approximations for the test statistic were known. In this paper the exact distribution has been given for 15 designs and comparison is made with the chi‐square and F approximation.
The pair chart*
Authors: Quade Dana 
Published: April 2008

Summary Given two random samples X1X2XnX and Y1, Y2Yny a “pair chart” is constructed as follows.Draw a rectangle of width nX units and height ny units. Starting from its lower left comer, draw a line one unit to the right (upwards) if the smallest observation in the combined samples is an X(a Y).Then, starting from the end of this line, draw another to the right (upwards) if the second smallest observation is an X (a Y).Continue through the largest observation, thus producing a path to the upper right comer of the rectangle.The paper explains how such a chart can be interpreted as a descriptive tool in comparing the two samples.There are figures which illustrate the typical effects on pair charts of differences between the underlying populations in location, scale, and shape.It is also shown how the pair chart can be used as an aid in calculating and interpreting various nonparametric procedures for the two‐sample problem These include: the one‐ and two‐ sided Kolmogorov‐Smirnov tests; the Wald‐Wolfowitz runs test; the Wilcoxon‐Mann‐Whitney test; Sukhatme's test for scale differences given both medians known; the Ansari‐Bradley scale test; Mood's squared‐rank test, and the Crouse‐Steffens modification of it; and Lehmann's two‐sample test. All of these are illustrated for three Examples, one of which has extensive ties.
On the existence of bivariate moments of lower order given the existence of moments of higher order
Authors: Vaart H. Robert van der 
Published: April 2008

SamenvattingDit artikel geeft een voorbeeld van een twee‐dimensionale waarschijnlijkheidsdcht‐heid met de eigenschap, dat het bestaan van momenten van de vorm E(gkyl) niet het bestaan garandeert van alle momenten van lagere orde, E(gmyn) met 0<m<k en 0<n<l, zulks in tegenstelling met de bekende situatie voor één‐dimensionale waarschijnlijkheidsverdelingen. Ook wordt bewezen, dat een noodzakelijke en voldoende voorwaarde voor het bestaan van alle momenten E(xmyn) met 0 < m < k en 0 < n < l is, dat de drie momenten E(xk), E(yl) en E(xkyl) bestaan, alsmede een iets algemener resultaat.