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SummaryA problem of communication arises as soon as the structure of an organization becomes too large for immediate total supervision.There are 5 main types of immaterial communication: directing, instructing, coordinating, controlling and informing communication. In practice there are many shortcomings of communication. The main cause is its self‐generation. Part of the communication generates by pressure on the side of the expedient, part of it generates by drawing on the side of the recipient. The consequence is too much and too little communication.For a good system of communication it is necessary to organize it instead of leaving it to uncontrollable forces of self‐generation. Some measures are given.

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.

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).

SummarySome statistical problems in the textile industryPart A. Production control in a spinning mill.It is pointed out that the function of planning is as important as the functioit of inspection. Sound planning requires reliable knowledge of the actual performances of men and machines. As to the machines, the actual amount of drafting of a spinning mill can not be computed from the speed and diameters of the rollers; instead it is necessary to use a working diameter of the roller found by experimental determination of the lengths of the ingoing and outgoing yarn. The amount of variation in outgoing yarn thickness can be computed from the variation in the ingoing yarn, the amount of draft and the amount of doubling. The necessary formulae are developed and illustrated.Part B. Weavers' efficiencyApart from servicing the machines, the weaver has to spend a certain portion of his time in reparing breaks in the yarn. If too many weavers are employed, they will part of their time have nothing to do; if too few, the machines will stand idle, because breaks can not be repaired soon enough. A formula is developed for finding the number of personnel that will reduce losses to a minimum.

Summary  (Statistical Aspects of Apparel Sizing).A description of the statistical principles underlying the design of a sizing system for apparel. The body measurements can be divided in primary and secundary measurements. The primary are independent variables, the secondary are highly correlated with the primary measurements. The choice of the primary measurements depends on the size of the tolerances, permitted in the other measurements and on the residual standard deviations after adaption of the regression equations. People are classified according to their primary measurements. The interval between two successive classes is two times the tolerance. The ideal class system is that in which as many people as possible fall within a limited number of classes.

The conditional expression of alternative life strategies is a widespread feature of animal life and a pivotal adaptation to life in seasonal environments. To optimally match suites of traits to seasonally changing ecological opportunities, animals living in seasonal environments need mechanisms linking information on environmental quality to resource allocation decisions. The butterfly Bicyclus anynana expresses alternative adult life histories in the alternating wet and dry seasons of its habitat as endpoints of divergent developmental pathways triggered by seasonal variation in preadult temperature. Pupal ecdysteroid hormone titers are correlated with the seasonal environment, but whether they play a functional role in coordinating the coupling of adult traits in the alternative life histories is unknown. Here, we show that manipulating pupal ecdysteroid levels is sufficient to mimic in direction and magnitude the shifts in adult reproductive resource allocation normally induced by seasonal temperature. Crucially, this allocation shift is accompanied by changes in ecologically relevant traits, including timing of reproduction, life span, and starvation resistance. Together, our results support a functional role for ecdysteroids during development in mediating strategic reproductive investment decisions in response to predictive indicators of environmental quality. This study provides a physiological mechanism for adaptive developmental plasticity, allowing organisms to cope with variable environments. ; European Union's FP6 Programme (Network of Excellence LifeSpan FP6/036894), FCT fellowship (SFRH/BD/45486/2008).