bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some mathematical aspects of reliability problems*
Authors: de Boer J. 
Published: April 2008

SamenvattingDe vraag naar het verband tussen de betrouwbaarheid van een systeem en die van zijn onderdeien leidt tot problemen waarvan enkele behandeld worden. Bij systemen met overtolligheid {die de betrouwbaarheid niet altijd verhoogt) wordt onderscheid gemaakt tussen warme en koude reserves.Elk van deze gevallen heeft een analogie met een bepaald wachtprobleem. Een practisch voorbeeld met een koude reserve wordt uitgewerkt.
Wachten in het wegverkeer*
Authors: de Lange S. J. 
Published: April 2008

SummaryFirst a brief survey of different waiting situations in road traffic is given, classified after the applicability ofqueueing theory. In section 3 and 4 is indicated to what extent queueing theory may be used to solve problems related to respectively, an intersection with fixed‐cycle traffic lights, and to the crossing of a highway.The article concludes with some considerations about the interpretation of mean waiting time.
On a waiting time problem in physiology
Authors: ten Hoopen M. , Reuver H. A. 
Published: April 2008

SamenvattingVoor een wachttijdprobleem, dat ter sprake komt in de quantum theorie van de visuele waarneming en bij een onderwerp uit de theoretische neurofysiologie, wordt een benaderde oplossing gegeven.Vergelijkingen worden gemaakt met de exacte oplossing en met uitkomsten van een Monte Carlo simulatie.
Interne leveringen in de inzet‐afzetanalyse
Authors: Neudecker H. 
Published: April 2008

SummaryBy applying this relation all results in the two definition systems can be translated into each other. In this note we will analyze some relationships between increments in gross and net production.It turns out that in case the external delivery structure changes {the non‐diagonal coefficients of A), relative increments in gross and net production are identical.A further result is that neither relative nor absolute increments in gross and net production are identical in case of changes in the internal delivery structure {the diagonal coefficients of A).The third result is that relative increments in gross and net production are identical in case of a change in final demand.Input‐output analysis can be set up in gross or net terms. In the first case the internal deliveries of a sector are included in the table, in the other case they are neglected. These two different approaches give rise to two different leontief matrices: A and D.Stone determined a relation between the two matrix multipliers (I‐A)‐1 and (I‐D)‐1
Wiskunde en besliskunde
Authors: Kriens J. , Aandacht Ik dank U voor Uw 
Published: April 2008

SummaryMijne Heren Curatoren en Leden van de Raad van Toezicht, Mijne Heren Professoren, Lectoren en Docenten, Dames en Heren Leden van de Wetenschappelijke Staf, Dames en Heren Studenten en voorts Gij alien, die door Uw aanwezigheid blijk geeft van Uw belangstelling,
Automatic processing of quality data of rayon tire yarns and cords*
Authors: Ottens F. 
Published: April 2008

SamenvattingAls voorbeeld voor automatische verwerking van kwaliteitsgegevens wordt een systeem beschreven voor het verwerken van een aantal garen‐ en koordeigen‐schappén van alle in de Nederlandse AKU‐bedrijven gesponnen rayon banden‐garens. Het routine‐onderzoek van de monsters wordt uitgevoerd op een Centraal Laboratorium, terwijl voor de bewerking van de waarnemingsuitkomsten gebruik wordt gemaakt van een tweetal computers (EL‐X1 en IBM 1401) van het AKU‐Rekencentrum.Eerst wordt de gang van zaken op het laboratorium en op het Rekencentrum besproken, waarna de, in de computerprogramma's ingebouwde, rekenkundige en statistische procedures uitvoerig worden toegelicht. Besloten wordt met een opsomming van de voordelen, welke door de invoering van het systeem zijn verkregen.
Variantieanalyse met behulp van een computer*
Authors: Kuipers H. A. 
Published: April 2008

SummaryAnalysis of variance with the aid of a computerThe outlines are given of a multi‐purpose program for the analysis of a factorial design with at most four factors by means of an electronic computer. Special attention is paid to its possibilities and to the difficulties which can arise in designing such a program, that is to be used for more than one purpose, e.g. for a simple Student‐test as well as for fitting regression lines, testing their parallelism and determining their horizontal distances.
Enkele algemene beschouwingen in verband met de uit‐voering van het Deltaplan*
Authors: Dronkers Dr. J. J. 
Published: April 2008

SummaryThe object of this paper is to show some statistical investigations concerning the determination of the design of the dams of the Delta Plan in the Netherlands.For the determination of the height of the dams, regarding overflow, statistical analysis must be applied on the actual observations of stormflood levels and wave heights. The extrapolation of the frequency curves of these data is one of the basic problems. The frequency curves of wave heights, periods etc. are determined by means of an electronic computer. An important object of study is the wave attack on the dam or dike. The damage due to wave attack will usually be determined by means of model wave tests in an Hydraulic Laboratory. The results determine the shape of the dike, especially the incline of the slopes and the materials of which the slope is constructed e.g. stone or asphalt.The economic decision problem shows the background of the determination of the optimal dike construction, in connection with the amount of money to be invested in dikebuilding: after optimal dike construction the expected capitalized values of all future losses by damage and the costs to be invested must be minimal. It is clear that the determination of these expected losses also depends on statistical investigations.
Een studie omtrent de cirkulatie van materieel*
Authors: van Rees J. 
Published: April 2008

SummaryThe circulation of rolling‐stock‐units in a scheduled transportation system is formulated in terms of Flows In Networks.This formulation enables us to develop a convenient method to find a circulation of rolling‐stock which is optimal with respect to the total cost.Basic data are the time‐table and the capacity, needed in each scheduled train, tram, bus or flight. In addition also the case in which there are two different types of rolling‐stock‐units with respect to their capacity is considered. Especially the rate of using the two types is investigated against total cost.
Enige ervaringen bij de ontwikkeling van een standaard‐toetsingsprogramma*
Authors: Mokken R. J. 
Published: April 2008

SummaryThe continuous improvement in velocity and capacity in the construction of modern computers, the development of programming languages and the possibilities of exchange and wider application of programmes might easily lead the uninitiated to overoptimistic views and expectations considering the saving of time and even the elimination of programming effort.
Opmerkingen en berekeningen betreffende “Poisson‐proces met interrupties” van J. C. A. Zaat
Authors: Runnenburg J. Th. , Vervaat W. 
Published: April 2008

SummaryIn an earlier paper by J.C. A. ZAAT an interrupted Poisson process was studied. Here we clarify some of the results there obtained. The process is obtained from a stationary Poisson process on the real axis by covering the axis with a sequence of adjoining intervals which have alternatively length a and b, the first left‐hand endpoint of an a‐interval to the right of 0 being chosen in a stochastic point &#x006e;̈ with &#x006e;̈ <a + b, where y is independent of the Poisson process, and omitting the points indicated by the Poisson process in the intervals with length b. It is here shown, that the distribution of the length of an interval between two successive points in the interrupted Poisson process is the same for all intervals that do not contain 0 if and only if &#x006e;̈ has a rectangular distribution over [b, a + b]. The interrupted process is periodic and non‐stationary. The common distribution function of the interval lengths in the interrupted process is denoted by G(y). Its Laplace‐Stieltjes transform is obtained.If&#x006e;̈ has a rectangular distribution on [0, a + b] the interrupted Poisson process is stationary, but the distribution of the length of an interval between two successive points in the interrupted process is now different for different intervals. For each distribution ofy over [0, a + b] the distribution of the length of the interval between the nth and the (n + I)st point to the right ofO in the interrupted Poisson process tends to the distribution function G(y) as n tends to infinity. Somehow ZAAT based his calculations exclusively on this stationary distribution.
Een prijsindex van nieuwe personenauto's, 1950–1965*
Authors: Cramer J. S. 
Published: April 2008

SummaryIn constructing a price index of new motorcars the main problem is how to deal with the introduction of new models and with quality variation generally. The first difficulty is turned by compiling year‐to‐year indices based on models that each account for 2 per cent or more of total sales in either year. The shifting basis of these indices comprises from 7 to 15 models which together account for 45 to 70 per cent of total registrations. All models are subject to minor improvements; this quality variation is taken into account by representing increases in horse power and overall length by equivalent price reductions. The elasticity coefficients involved in this translation are derived from a cross section analysis of prices and technical characteristics of some fifty widely ranging models in 1964.A price index for the period from 1950 to 1965 is then obtained by linking successive year‐to‐year indices. Over the whole period list prices have risen by a third, to a large extent as the result of changes in purchase tax; this price rise is just about offset by imporvements in quality of some 2 per cent per annum.
De fout bij het gebruik van een tweetal benaderingsformules
Authors: van Noerssen R. F. 
Published: April 2008

SummaryFor the sake of efficiency, the use of simplified formulae in item analysis is recommended. For adequate use of such formulae the systematic error must be known. For two important formulae this error is estimated: the KUDER‐RICHARD‐SON‐21 (instead of 20) and a formula for the correction of the spurious part‐whole correlation.As for the KR, if itemscores are 1 andO, the KR20 is given in (I) and the KR21 in (2). The difference dr between them, given in (5), is directly proportional to the variance of the itemdifficulties. This variance turns out to be rarely greater than 0,05. If the distribution of itemdifficulties is unimodal, a value greater than 0,05 is indeed improbable in four‐choice tests. The KR21, which does not need an item analysis, can be used as a substitute of the KR20. The KR21 coefficient itself is an lower limit, the KR21 plus dr ‐ estimated by (6) ‐ a probable upper limit of the KR20 coefficient.The part‐whole correlation of tests is spurious. If one wants to correct for this spuriousness it is theoretically preferable to estimate the part‐parallel test correlation instead ofthe part rest correlation. This is done here with the assumptions of classical test theory. The part‐parallel test correlation is given in (12), the easily computed first approximation, called A, in (13) and the second approximation in (75), in which last formula the corrected correlation is expressed as a function of A, the standard deviations of part and whole, and the reliability of the test. One can compute with this formula a maximum A, below which the first approximation is sufficiently precise.
Tolerantiegebieden en toetsen voor Kwantielen*
Authors: Adriaanse R. P. 
Published: April 2008

SummaryAfter some general remarks about tolerance regions two simple cases are considered: the distribution‐free tolerance region and a one‐sided tolerance region for a normal distribution. For a p‐content tolerance region at confidence level γ the equivalent hypothesis‐testing problem is considered which, as a special case, includes the one sided quantile‐tests.
Statistiek en planning in de sociale sector*
Authors: Verstegt J. Ch. W. 
Published: April 2008

SummaryStatistics and planning do not function as yet in the social sector in the same way as they do in the economic sector, where national accounts and balances are used as frameworks for the integration of the various economic statistics.On the one hand economic sector studies can be made for the social sector as well, giving a picture of the total costs and the financing of the various kinds of social care; on the other hand it is necessary that for each kind of social care (education, medical care, care for the maintainance of law, order and safety, religious care, care for labour and spending of leisure time, housing and social work) social input‐output tables be composed regarding the “cared‐for” as well as the “caretakers”, giving in the form of a matrix the flows of persons passing through each sector of care.If projections are based on such matrices, planning becomes possible and in this way shortages and surpluses can be located in time and a long term policy can be pursued.The various basic statistics will have to be brought into harmony with the requirements of the composition of such input‐output tables for each cohort. To reach this goal two ways are open: either by collecting information for each individual entering a care‐sector about one or more previous situations or by following the individuals through various situations of entering, passing through and leaving care‐sectors. This latter method, the method of the so‐called longitudinal statistics, provides greater possibilities because extrapolation is easier and one can link the different previous situations. The relevant factors can be quantified and the data for model building become available.The development in registration and in automation makes the compilation of longitudinal statistics ‐far as necessary on a sample basis ‐ a practical possibility.
A Sequential distribution‐free two‐sample grouped test with three possible decisions*
Authors: van der Laan P. 
Published: April 2008

SummaryA sequential two‐sample grouped rank test with two possible decisions (onesided testing) developed by WILCOXON, RHODES and BRADLEY (1963) is generalized to a sequential test with three possible decisions (two‐sided testing) using a method given by SOBEL and WALD (1949). An auxiliary table with some moments concerning LEHMANN'S alternatives for the normal distribution, is given in order to facilitate the choice of the alternative hypotheses.
Bias in estimation from type I censored samples
Authors: van Zwet W. R. 
Published: April 2008

SummaryLet be a family of probability distributions on R1. This paper raises the question whether a parameter θ=θ (P), Pt, is estimable on the basis of a type I censored sample (i.e. censored on a fixed set C). Two theorems are given that state conditions on θ and C that ensure that θ is not estimable. The results are applied to estimation problems for the normal and POISSON distributions; it turns out that unbiased estimation is impossible in the majority of practical cases.
Steekproeven uit de halve cauchy verdeling
Authors: MIJNHEER J. L. 
Published: April 2008

Summary  Let x1…, xn be a sample from a distribution with infinite expectation, then for n→∞ the sample average x̄n tends to +∞ with probability 1 (see [4]).Sometimes x̄n 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.
Een indelingsprobleem
Authors: ANTHONISSE JAC. M. 
Published: April 2008

Summary  A branch and bound algorithm is given to solve the following problem: To each pair of elements (i,j) from a set X={l,…, n} a number rij with rij≥ 0, rij=rij and rij= 0 has been assigned. Find a prescribed number of disjoint subsets P1…,Pm from X, such that Experiments indicate that an optimal solution is usually found in a small number of iterations, but the verification may be rather time consuming.The algorithm may be used to find the minimum value of m for which a partitioning of X with z= 0 exists. The algorithm appears to be efficient for finding this ‘chromatic number of a graph’.
Autoverkopen en autopark in Nederland, 1950–1970
Authors: CRAMER J. S. 
Published: April 2008

Summary  This is a study of the demand for the ownership of new or firsthand cars, i.e. the demand of ‘first owners’ who habitually buy new cars which are then traded in long before they are obsolescent. Upon combining the evidence of various surveys with time‐series for 1950‐64 it is found that this ownership has an income elasticity of 2 and a price elasticity of – 1.25 in respect of the constant‐quality index of new car prices earlier provided. On the average new cars are traded in after three years so that roughly one third of the existing stock is replaced every year. These values together determine an equation for purchases of new cars which accurately predicts new registrations in 1965 and 1966. Projections for the years 1967‐70 are provided.In the model employed the total number of cars (including used cars) is determined by the active demand exerted by ‘first owners’ on one hand and by the hitherto fairly constant scrappage rates on the other. Projections of the overall ownership rate can therefore be derived from the forecasts of new registrations. The ownership rate will approach 80% around 1970, and it is likely that at that stage the current scrappage rates will cease to apply in view of the greater predilection for comparatively younger cars.
Het rekenkundig gemiddelde stijgingspercentage – een ondoelmatige groei‐indicator
Authors: TILANUS C. B. 
Published: April 2008

Summary  In business practice it happens that annual growth is measured by the ordinary (arithmetic) average of yearly growth percentages. It is argued that there are better methods in any case. A method requiring relatively much time is least squares. Methods requiring very little time are a) determining growth graphically, using semi‐logarithmic graph paper b) computing the geometrical average, which is nothing else than the n‐th root (if there are n+l observations) of the ratio between the last and first observation.In a table, a survey of bias and dispersion of three estimators is given for a few numerical cases.
Representation of ANOVA models with vectors and vector spaces
Authors: Verdooren L. R. 
Published: April 2008

Summary The use of vectors and vector spaces for the representation of the fixed‐effects models for the analysis of variance (ANOVA) is well‐known. This representation gives a clear understanding of the estimation and hypothesis testing problems.A similar representation can be used for the random‐effects models and some mixed models. As a result the distribution and the expectation of the mean squares in the ANOVA table can easily be derived.
Rechtszekerheid bij onzekerheid
Authors: Sittig J. 
Published: April 2008

SummaryLegal security under uncertaintyThere are two sources of losses in decision making: collective judgment and uncertainty. The situation can be summarized as follows:Minimization of losses can be achieved by using optimal decision rules. The effect of this method differs in the three cases treated. The analogies and differences of the three cases are discussed in this paper.Lezing gehouden op de Statistische Dag 1969.
Some remarks concerning the quotient of sample median and sample range for a sample of size 2n+1 from a normal distribution
Authors: Haan L. de , Runnenburg J. Th. 
Published: April 2008

Introduction and summaryConsider an ordered sample (1), (2),…, (2n+1) of size 2n+1 from the normal distribution with parameters μ and s̀. We then have with probability one (1) < (2) < … < (2n+1).The random variable
n
=(n+1)/(2n+1)‐(1)that can be described as the quotient of the sample median and the sample range, provides us with an estimate for μ/s̀, that is easy to calculate. To calculate the distribution of hn is quite a different matter***. The distribution function of h1, and the density of h2 are given in section 1. Our results seem hardly promising for general hn. In section 2 it is shown that hn is asymptotically normal.In the sequel we suppose μ= 0 and s̀= 1, i.e. we consider only the “central” distribution. Note that hn can be used as a test statistic replacing Student's t. In that case the central hn is all that is needed.
Investeren en onzekerheid
Authors: Verheyen P. A. 
Published: April 2008

Summary Investment and uncertaintyAfter a few introductory remarks about the necessity of uniform definitions about plan horizon, returns, expenses, interest factor ett. for all investment alternatives and the necessity of an also uniform way of prediction, several models on investment analysis which are known from literature are briefly discussed. For simplicity there is only one decision variable (i.e. capacity); the variables influencing it are called exogeneous variables. These exogeneous variables may be deterministic and then one has to maximize the sum of the discounted cash flows from each project where different levels of investment into a project are supposed to exclude each other. The maximization may be subject to restrictions or not. If the exogeneous variables are stochastic one has to maximize the expected utility, mostly defined by the expected value and the variance of the discounted cash flows. The way to carry this out is simulation. Also portfolio analysis may be used, but there are some objections against this method, which are discussed.
Arm ‐ en ‐ rijk oftewel: leren ‐ de dommekracht onder de inkomenslift*
Authors: Somermeijer W. H. 
Published: April 2008

Summary This address deals with factors contributing to the inequality of income, with particular reference to the Netherlands and to the U.S.A. Sections 2 and 3 survey the shape of the income distribution curve, and the (possible) impact of the length of the reference period and of capital income on income variance.Section 4 shows the modest contribution of intergroup (compared with intra‐group) differences in (mean) income, after classification of income recipients by occupation, age and sex.Special attention is paid to estimation of schooling and intelligence effects in multivariate analysis. All systematic factors taken together appear to account for less than 1/3 of the total income variance, so that a major part of it is still unexplained; mainly entrepreneurial income seems to be responsible for it.Finally, possible changes in income distribution ‐ autonomous or resulting from policy measures ‐are discussed summarily.
Note on the generation of most probable frequency distributions
Authors: Lisman J. H. C. , Zuylen M. C. A. van 
Published: April 2008

SummaryThe most probable distribution of a stochastic variable is obtained by maximizing the entropy of its distribution under given constraints, by applying Lagrange's procedure.The constraints then determine the type of frequency distribution. The above holds for continuous as well as for discrete distributions.In this note we give a survey of various constraints and the corresponding frequency distributions.