Ordering the data for Lee's algorithm

It is shown that, when using Lee's algorithm for interconnection programs, if the order in which the tracks are routed is determined by the distance between the start and end points of each tracks, on average more paths may be placed than if the order is chosen at random.     

The interpretation of detection data through direct multivariate frequency analysis.

Many psychological experiments generate data that form multidimensional tables of frequencies. Although these tables are conventionally analyzed by such theoretical models as signal-detection theory, a direct and atheoretical analysis of the associations present in the data gives additional valuable information about the underlying detection processes. The present article demonstrates an application of these models to psychophysiological data, which provides an attractive compliment to the more usual signal-detection theory analysis. It is suggested that direct frequency analysis can investigate quite complicated patterns of association; furthermore, it allows approximate statistical test of specific hypotheses to be run. Thus, it provides a valuable adjunct to theoretical models. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Consistency of performance under stable conditions of work.

Weekly production data were obtained over a 3?-yr period from a group of 27 women sewing-machine operators and a group of 19 women in folding and packaging jobs. Average intercorrelations (r̄) computed between work periods separated by time intervals (K) ranging from 1–278 wks revealed an orderly decline in the magnitude of r̄ as K assumed larger values. For both groups, the regression of r̄ on K can be described by an equation of hyperbolic form with an added constant. The constant serves as an estimate of an asymptotic level approached by r̄ as the interval between production periods increased. Subsequent analyses indicated that a major portion of the correlation between production periods was attributable to week-to-week stability in absolute levels of output. Factors believed to contribute to the consistency of performance data are discussed. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermoelastic and thermomechanical studies on natural rubber vulcanized in the swollen state

Three samples of natural rubber were crosslinked in n-decane solution. After the solvent had been removed, a thermodynamic investigation was made of the elastic behaviour of the samples in simple extension. Thermoelastic measurements at constant pressure and length were carried out on the first two samples. The third sample was subjected to a thermomechanical heat of extension study using a Calvet microcalorimeter. The experiments enabled the temperature coefficient of the mean-square unperturbed dimensions, 〈r²₀〉, to be derived. From the thermoelastic measurements average values for dln $\text{〈r}{}^2{}_0\text{d}\text{T}$ of (0.44 ± 0.08) × 10^?3deg^?1 and (0.38 ± 0.07) × 10^?3deg^?1 were obtained, whilst the thermomechanical measurements gave a value of (0.54 ± 0.04) × 10^?3deg^?1.     

Behavioral consequences of crowding in the deermouse (Peromyscus maniculatus).

Hypothesized that, when the degree of crowding is manipulated by varying group size in cages of equal size, it is probable that crowded animals will engage in more contact than uncrowded animals. Home-cage observation of 24 male and 24 female deer mice indicates that crowded Ss do, in fact, engage in more contact behavior. Both home-cage observation and testing in pairs for pain-elicited aggression reveal that (a) crowded Ss display more agonistic behavior than uncrowded Ss, and (b) agonistic behavior increases with prolonged crowding. Support is obtained for the theory that the effect of crowding derives from contact with conspecifics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parabolic reflectors formed by inflation

Paraboloids of revolution over 1 meter in diameter have been formed from flat sheets by inflation without the use of a mold or template. Quality is adequate for microwave use and for most high-concentration applications for focusing solar energy. The process is suitable for making reflectors in ones or twos to special focal lengths and diameters, but could also be automated for production runs.     

Replicating sequences of bernoulli trials in simulation modeling

An efficient method for computer generation of replicated sequences of Bernoulli trials is described. The sequences are utilized as input for simulation models of systems where the output response is a function of the number and timing of successes in a Bernoulli input sequence. The method is evaluated on the basis of unit costs for the required computations. The proposed method is preferred provided a certain inequality involving the unit costs is satisfied. The condition is almost always satisfied in cases where the simulation modeling approach is most appropriate, that is when the success probabilities of the Bernoulli trials are small.