bluuebunny/crossref_metadata_2025_split huggingface dataset:
Statistiek en experiment*
Authors: Hamaker H. C. 
Published: April 2008

SummaryStatistics and ExperimentsAfter a brief survey of the general importance of the statistical design of experiments, two particular examples are discussed in detail, one dealing with a series of 7 simple experiments on the proper conditions for the production of swaged joints, the other being a 3 × 3 × 3 design on emission in radiovalves. These examples provide illustrative material for some problems of a general nature, to which little attention is paid in textbooks on the subject. Often more factors are mentioned than can be conveniently incorporated in a single experiment. One of the secrets of succesful experimentation lies in making a proper choice of those factors which should go into an experiment. Where experimentation is easy and rapid a series of simple two — or three — factor experiments is better than one complex design. Analysis of variance is not always needed; frequently too the data resulting from an experiment indicate that text‐book methods of analysis do not apply and the statistician or experimenter should be trained in recognizing such situations and in dealing with them. The paper ends with some general conclusions concerning the present and future status of statistics as an integral part of experimental science.
Statistiek of experiment*
Authors: van der Burg A. R. 
Published: April 2008

SummaryStatistics or ExperimentIn a manufacturing firm one has often the choice between study of the normal process of production and observation by means of experiments. A drawback of the first method is the complexity of factors (relevant and irrelevant) influencing the observed process. However, the arsenal of statistical techniques allows to dissect even the more complex processes into its separate factors. In this way statistics makes experiments superfluous.The choice between the two working methods is essentially a problem of economic optimum (see figure). The minimum net return has to be found from the difference between the gross return (O) and the cost of the experiment (E) and the analysis (A).
Optimale revisietijd
Authors: van der Burg A. R. 
Published: April 2008

SummaryOptimum period of overhaul, a case‐studyA general formula is given, when to proceed to an overhaul in such a way that the costs of wear and those of overhaul together will be a minimum (par. 2). In par. 3 the practical solution for cells in electrolysis is discussed. First a nonstochastic model is considered, then the more realistic stochastic model. It is proved that an overhaul is not indicated after a certain space of time or after a certain increase in the costs, but when a certain absolute level of the costs (corresponding with a certain electrical tension) is reached irrespective of what went before. A formula (14) to this end is given. Attention is also paid to the problem of the numerical evaluation.
De meting van de produktiviteit
Authors: Nanninga H. G. C. 
Published: April 2008

SummaryThis article presents a survey of the different methods of productivity measurement, it describes what hitherto has been done in the Netherlands in this field. After an explanation of the concept of productivity and a description of some pre‐war and recent publications on productivity trends in a number of branches of manufacturing industry, the main object is formed by a description of the so called interfirm comparisons of productivity. It stresses the practical importance of comparisons based on quantitive ratios (labour requirements per unit of product, etc.).
Produktiviteitsverhoging op grote schaal: Maatnormalisatie van kleding
Authors: Sittig J. 
Published: April 2008

SummaryThe article contains a short review of a campaign, undertaken in Holland during the last 12 years to arrive at standardized sizes for women's and men's clothing. The first campaign was undertaken by a department store, the second one by the clothing industry.The operational value of a sizing system depends on the value of three parameters which are not, of course, independent of each other: coverage of the system, number of sizes and average cost of alterations.The basis of the standardization is furnished by measuring a sample of the population of customers and by measuring the fitting‐tolerances of clothing.The proposed sizing systems are:a. Ladies' dresses — a two‐dimensional system based on waist girth and length of back, containing 14 sizes and giving a coverage of 90%.b. Men's suits — a system with a variable number of dimensions (2 to 4). The identification dimensions are waist girth, length of leg, hip girth and inclination of shoulder. The proposed system gives a coverage of 90% with 34 sizes. Both systems have been experimentally verified.Stress is laid on the necessity of an international sizing standardization.
Efficiency by statistics*
Authors: Moroney M. J. 
Published: April 2008

SamenvattingEfficiency door Statistiek.Management (bedrijfsleiding) heeft een vocabulaire, maar geen grammatica. – De wiskunde heeft een grammatica, maar geen vocabulaire. – De wiskunde heeft een beperkt toepassingsbereik, dat de verleiding biedt, vervormingen toe te passen. – Het inzicht in de natuur van het probleem is belangrijker dan het goochelen met symbolen. – De grote moeilijkheid is de vertaling van het probleem in mathematische termen. – De manager (leider van het bedrijf) heeft recht op een proef voordat hij tijd en inspanning aan de zaak besteedt. – Aspecten van bedrijfsleiding, waarbij het statistische contact vaak onderschat wordt. – Kort beschreven gevallen, die de praktische resultaten van efficiency door statistieken illustreren.
Rationalisatieonderzoek in de bosbouw*
Authors: Bol M. , Gerritsen A. G. 
Published: April 2008

SummaryEfficiency research in forestryIn this and in a preceding paper (Statistica Neerlandica 13 nr 2) some applications of statistical methods in forest research, particularly in the field of rationalization of forest‐labour, are described.In the first article comparative investigations of hand‐tools and working‐methods used in the planting of pine forests are discussed, in this second paper the composition of a measured time‐tariff for felling, lopping and barking of Scotch pine (Pinus sylvestris L.) is described.
Bedrijfsvergelijking als efficiencymeter*
Authors: Nonninga H. G. C. 
Published: April 2008

SummaryBusiness comparison as an efficiency measure.The statistical comparisons of the various degrees of productivity are made in such a way that the differences stated between the participating enterprises are to be attributed to the differing efficiency of the internal organization of those enterprises.On the one hand those differences are expressed by means of a comparison of ratios per section of the enterprises, such as manhours, or machine hours per unit of product, on the other hands by means of establishing the relationship between the level of a particular sort of costs and the various factors influencing the extent of those costs.
Een nomogram voor betrouwbaarheidsgrenzen van quantielen en overschrijdingskansen bij normaal verdeelde grootheden
Authors: Levert C. 
Published: April 2008

SummaryA nomogram for confidence intervals and exceedance probabilities.In this paper two problems are considered regarding the probability β that an observation on a normally (μ, σ2)‐distributed random variable exceeds a given value W: If μ and σ2 are unknown, the two problems are as follows:1)if Wis given, to determine a confidence interval for β and2)if β is given, to determine a confidence interval for W.For these two essentially equivalent problems graphs are given from which the confidence intervals can be determined. The graphs are given in terms of: and are based on an approximation for the distribution of x¯+ks.
The statistics of systems of simultaneous economic relationships*
Authors: Thell H. , Kloek T. 
Published: April 2008

SamenvattingDe statistische problemen van stelsels van simultane economische relaties.Dit artikel handelt over de schattingsproblematiek van stelsels van simultane vergelijkingen in de economie. Na een uiteenzetting van een aantal essentiele begrippen in § 2 (zoals structurele en herleide vorm‐vergelijkingen, volledigheid van net stelsel, exogene en endogene variabelen, tevoren bepaalde en gezamenlijk afhankelijke variabelen) worden in § 3 de klassieke veronderstellingen gespecificeerd waaronder schatting van de coefficienten van de vergelijkingen plaats heeft. In § 4 wordt de methode van kleinste kwadraten in twee ronden behandeld, in § 6 een aantal verwante schattingsmethoden; § 5 geeft een korte uiteenzetting van het identificatieprobleem.De verdere bijdragen hebben betrekking op het gebruik van principale compo‐nenten van tevoren bepaalde variabelen voor het geval het aantal van deze variabelen niet gering is in vergelijking met het aantal waamemingen (§ 7); op een iteratieve methode die gebruikt maakt van alle a priori informatie van het stelsel (§ 8); op de schatting uit eindige steekproeven benaderd aan de hand van een reeksontwikkeling naar machten van het aantal waamemingen (§ 9–11); en tenslotte op de relatie tussen dit onderwerp en dat van de canonische correlatie‐theorie (§ 12), zulks in verband met een doelmatige definitie van een correlatie‐coëfficiënt die de mate beschrijft waarin de variatie van de groep van tevoren bepaalde variabelen weerspiegeld wordt in de variatie van de groep van gezamenlijk afhankelijke variabelen.
Het Indian Statistical Institute te Calcutta Organisatie en werkprogramma
Authors: Derksen J. B. D. 
Published: April 2008

SummaryThe Indian Statistical Institute at Calcutta.After an introductory statement on the organisation of official statistics in India the author describes the various departments of the Indian Statistical Institute, and its contributions to the development of sampling methods, in mathematical statistics and theory of probability, biometrics, psychometrics, statistical quality control, demography and economic development planning. The Institute occupies a leading position in India as a national and international centre of statistical research and training at very advanced levels.
The conduct of the sample average when the first moment is infinite
Authors: MIJNHEER J. L. 
Published: April 2008

Summary  Many books about probability and statistics only mention the weak and the strong law of large numbers for samples from distributions with finite expectation. However, these laws also hold for distributions with infinite expectation and then the sample average has to go to infinity with increasing sample size.Being curious about the way in which this would happen, we simulated increasing samples (up to n= 40000) from three distributions with infinite expectation. The results were somewhat surprising at first sight, but understandable after some thought. Most statisticians, when asked, seem to expect a gradual increase of the average with the size of the sample. So did we. In general, however, this proves to be wrong and for different parent distributions different types of conduct appear from this experiment.The samples from the “absolute Cauchy”‐distribution are most interesting from a practical point of view: the average takes a high jump from time to time and decreases in between. In practice it might well happen, that the observations causing the jumps would be discarded as outlying observations.
Het verdelen van steekproeven over subpopulaties bij accountantscontroles
Authors: KRIENS J. 
Published: April 2008

Summary  “Stratificationprocedures for a typical auditing problem”.During the past ten years, much experience was gained in The Netherlands in using random sampling methods for typical auditing problems. Especially, a method suggested by VAN. HEERDEN [2] turned out to be very fruitful. In this method a register of entries is considered to be a population of T guilders, if all entries total up to T guilders. The sample size n0 is determined in such a way that the probability β not to find any mistake in the sample, if a fraction p0 or more of T is incorrect, is smaller than a preassigned value β0. So n0 should satisfy (l‐p)n0≤β0 for p≥p0. A complication arises if it is not possible to postpone sampling until the whole population T is available. One then wants to take samples from a population which is growing up to T. Suppose one is going to take samples ni from e.g. r subpopulations Using the minimax procedure, it is shown, that in this case one should choose the sizes ni equal to (Ti/T)n0. The minimax‐value of the probability not to find any incorrect guilder in the r samples, taken together is equal to β0.
Abraham de Moivre en zijn “Doctrine of Chances”
Authors: VAN VEEN S. C. 
Published: April 2008

Summary  ABRAHAM DE MOIVRE (1667 Vitry ‐ 1754 London) was one of the foremost pioneers in the domain of the theory of probability. His principal contributions are laid down in his “Doctrine of Chances” (three editions, 1718, 1738, 1756). This classic work, almost forgotten, is now republished, as a splendid photographic reprint of the third (last) edition, by Chelsea Publishing Company of New York (1967).In this article we specially mention his original contributions respecting the problem of the duration of play, the theory and application of recurrent series, the theory of runs, and especially his extension of the value of BERNOULLI'S theorem by the aid of STIRLING'S theorem.In the last mentioned research DE MOIVRE obtained the equation for the curve of error, thus antedating LAPLACE by about 50 and GAUSS by 76 years. This important fact is discovered by KARL PEARSON in 1924.
Steriel of niet steriel, dat is de vraag
Authors: DRION E. F. 
Published: April 2008

Summary  This paper deals with a practical problem of sampling inspection, viz. the bacterial control of imported fishmeal (which is used in food for pigs). It was suspected that this fishmeal was often contaminated by salmonella‐bacteria, but only in about 0.5% of the samples the presence of these bacteria could be proved. An investigation by the Dutch National Institute of Public Health, at which 4 bags of fishmeal (about 50 kg) after homogenization were divided into 1000 samples of 50 grams each which were individually tested on the presence of salmonella bacteria, showed that nothwithstanding the homogenization the bacteria were very irregularly distributed. Every bag was contaminated, but only about 1.8% of the samples were infected. So the density of infection was low, but the fraction of infected bags was high.If the fishmeal were fed in a dry condition to the pigs the relevant parameter on which the condition of the fishmeal should be judged would have been the mean number of bacteria per gram of fishmeal. However, as food for pigs is mixed with water the bacteria have the possibility to increase in number so the relevant parameter to judge a batch of fishmeal is the fraction of non‐sterile bags.At the end of this paper a sampling scheme is given, including a system of penalty for producers who regularly supply contaminated fishmeal which will in a relative short time improve the quality of the imported fishmeal.
Winstgevendheid en winstkansen bij valuta‐arbitrage
Authors: van de Panne C. , Stranders A. 
Published: April 2008

SummaryProfits and Profit Probabilities in Exchange Arbitrage.For the case in which in each of a number of countries buying and selling prices for the currencies of the other countries are quoted by a number of banks, a method is developed by means of which the chains of transactions which yield the highest profit, if any, are traced systematically. This method is applied to constellations of buying and selling prices in five countries at three different points of time; the maximum proft of chains was0.090, 0.477 and 0.143 per thousand, respectively.When it is assumed that the logarithms of changes of buying and selling prices are normally distributed around o with constant variance and temporally independent, the probability that there is a positive profit can be determined for each chain at each point of time as soon as an estimate of the variance is available. In the same way the mathematical expectation of profit, when possible losses are considered as o (no action being taken), can be determined. Both quantities are calculated for two points of time for a limited number of chains.
Some remarks on business tendency surveys
Authors: van Beeck J. G. , Engberts G. E. , Lisman J. H. C. 
Published: April 2008

SamenvattingEen onderzoek werd ingesteld naar de kwantitatieve betekenis van de uitkomstenvan de conjunctumtest. Resultaten, verkregen met behulp van de gebruikelijke methode van de conjunctuurtest, werden vergeleken met traditionele indices, in beide gevallen gebaseerd op het zelfde grondmateriaal, zodat storingen tengevolge van onvolkomenheden in berichtgeving en interpretatie a priori waren uitge‐schakeld.Het specifieke gebrek aan informatie, dat aan de begrippen “stijgen” en “dalen” inhaerent is, blijkt een aanwijsbare nadelige invloed te hebben op de kwaliteit van de regressie; men vindt coefficienten die in het algemeen tussen 0,8 en 0,9 liggen. In de praktijk zijn deze belangrijk lager. Indien men bovengenoemde onvolkomenheden in belangrijke mate zou kunnen opheffen, dan zouden de correlatiecoefficienten toch beneden dit niveau blijven. Van de omstandigheden zal dan afhangen of de relatie kwantitatief bruikbaar is.Introductie van het percentage gelijkblijvers in de regressievergelijking bleek geen verbetering te geven. Tot op zekere hoogte kan met lineaire regressie op het saldo van de percentages „stijgers” en „dalers” warden volstaan; de regressie‐coefficient houdt evenwel enig verband met het niveau van de te verklaren variabele.Indien een seizoenpatroon aanwezig is, geeft dit correlatie‐technisch aanleiding tot geflatteerde uitkomsten, zodat seizoencorrectie aanbeveling verdient.
Een onderzoek naar de invloed van 2 mg vitamine K1 bij vroeggeborenen*
Authors: de Bruijne J. I. , Bloemena En A. R. 
Published: April 2008

Summary An investigation on the influence of a dosage of 2 mg vitamin K1 in premature infants An investgation is described, which was designed to answer two questions: 1) whether a dosage of 2 mg vitamin K1 applied to premature infants is sufficient to warrant a rapid decrease of the prothrombintime during the first days of life, and 2) whether the dosage is innocuous with regard to the bilirubin content of the blood and the possibility of nuclear jaundice.
De kostprijs en statistiek*
Authors: Schmidt P. 
Published: April 2008

SummaryCost‐price and StatisticsThe cost‐price may be represented by the following formula: in whichK = the cost‐price;H = predetermined quantities of raw and other materials and of machine‐and manhours;P = prices of the quantities H per unit;R = fraction of interest;t = period during which the capital is tied up.It is demonstrated that in many cases the cost‐price factors are interdependent. Besides it is mentioned that under the presentday accounting practices the cost‐price is generally treated as an exactly determinable quantity, although its stochastic character is very often evident.A comparison is made with statistical quality‐control. The view is upheld that the technique used in such cases will be of importance in realizing a cost‐price which to a greater extent is adapted to statistical principles.
Een model voor discreet verdeelde grootheden met negatieve correlatie
Authors: Levert Dr. C. 
Published: April 2008

SummaryA model for negatively correlated variables.A mathematical model is described with which a bivariate distribution of two negatively correlated binomially distributed variables can be constructed. Let be given a vase with W white, Z black and R red balls; N = W + Z + R; P1= W: N;P2 = Z: N.Let be drawn a random sample with replacement of n balls. Let be w = number of white en z = number of black balls; w + z < n. Then and are binomially distributed variates, correlated according to (1).At the end of the paper the author formulates the following statistical problem: let be drawn a finite number of times () such random samples of n balls. The pairs w, z furnish a correlation coefficient r, which itself is a stochastical variable. How is the distribution of? In particular what are the expectation (, N) and the standard deviation (k, n, N)
De spreiding van inschrijvingsbedragen op openbare aanbestedingen
Authors: Bakker E. 
Published: April 2008

SummaryThe Dispersion of Bids in Public ContractingThe analysis is concerned with the coefficients of variation (standard deviation divided by mean) of bids in public contracting by the municipal authorities of a big city in the period 1946–1953. Three factors are investigated as to their impact on these coefficients of variation. The first is time; it is shown that the dispersion decreased gradually, probably as a result of increased cartelization. The second is the nature of the object (road building and earth‐work, waterworks, and sewerage); waterworks seem to be characterized by a smaller dispersion of bids. The third is the size of the object, and it is shown that the dispersion is smaller for large objects than for small ones, probably as a result of the greater care of cost calculation for large objects. An attempt is also made to ascertain the interaction of these factors.
Theoretical aspects of sequential designs*
Authors: Armitage P. 
Published: April 2008

SamenvattingTheoretische aspecten van sequente proefopzettenEr wordt een korte beschrijving gegeven van de theoretische achtergrond van afgeknotte sequente schema's. Deze methoden zijn het verste ontwikkeld voor de situatie, waarin de waarnemingen bestaan uit een serie preferenties voor één van twee te vergelijken behandelingen. Ook aan enige recente ontwikkelingen voor continue grootheden wordt in dit artikel aandacht besteed.
Practical estimators for sampling on successive occasions
Authors: de Vries M. 
Published: April 2008

SamenvattingIn een steekproefschema dat zich uitstrekt over enige tijd kan de steekproefomvang varieren van periode tot periode. Een aantal schattingsmethoden worden voorgesteld die zoveel mogelijk informatie benutten uit de voorafgaande waarnemingen. Ze worden vergeleken met de regressieschatting die theoretisch optimaal is. Bij net waarnemen echter van een zeer groot aantal kenmerken is de regressie‐schatting niet langer bruikbaar als gevolg van de grote aantallen berekeningen.De voorgestelde schatters verliezen aan precisie maar veroorzaken geen reken‐technische problemen.
Statistics, Past, Present and Future*
Authors: Kendallo M. G. 
Published: April 2008

SamenvattingIn deze voordracht wordt een overzicht gegeven van de ontwikkeling van de statistiek gedurende de afgelopen eeuwen, alsmede een visie op de toekomst. De beschrijving blijft daarbij uiteraard in grote brede lijnen, doch de markante gezichtspunten komen duidelijk uit. Ten aanzien van het toekomstig perspectief wordt aandacht gewijd aan: data‐processing, toepassingen van statistiek op juridisch en commercieel gebied, de taak van de electronische rekenmachines, besliskunde in bedrijven, problemen van menselijke en maatschappelijke organisatie e.d.