A harmonious encoding of instrument values by a nineteenth-century Parisian violin dealer

The study of three ledgers from the archives of a prominent Parisian violin maker’s workshop (active from 1796 to 1948) reveals that some of their content was encrypted. Presented here are the deciphering of the code and a discussion of its use in the context of the workshop. Charles-Adolphe Gand introduced this code around 1847 to encrypt values of antique/used violins he would buy and resell. His successors maintained the use of this code at least until 1921. Taking a few examples of instruments by Stradivari and other violin makers, researchers illustrate how the decoded ledgers (listing transactions for more than 2,500 instruments) are of high interest as historical sources documenting the margins, rebates, and commercial practices of these violin dealers. More generally, this article will contribute to better describing the evolution of the market for antique instruments of the violin family.     

Nonlinear methods for inverse statistical problems

In the uncertainty treatment framework considered, the intrinsic variability of the inputs of a physical simulation model is modelled by a multivariate probability distribution. The objective is to identify this probability distribution-the dispersion of which is independent of the sample size since intrinsic variability is at stake-based on observation of some model outputs. Moreover, in order to limit the number of (usually burdensome) physical model runs inside the inversion algorithm to a reasonable level, a nonlinear approximation methodology making use of Kriging and a stochastic EM algorithm is presented. It is compared with iterated linear approximation on the basis of numerical experiments on simulated data sets coming from a simplified but realistic modelling of a dyke overflow. Situations where this nonlinear approach is to be preferred to linearisation are highlighted.     

Interface Mutation Test Adequacy Criterion: An Empirical Evaluation

An experiment was conducted to evaluate an inter-procedural test adequacy criterion named Interface Mutation. Program SPACE, developed for the European Space Agency (ESA), was used in this experiment. The development record available for this program was used to find the faults uncovered during its development. Using this information the test process was reproduced starting with a version of SPACE containing several faults and then applying Interface Mutation. Thus we could evaluate the fault revealing effectiveness of Interface Mutation. Results from the experiment suggest that (a) the application of Interface Mutation favors the selection of fault revealing test cases when they exist and (b) Interface Mutation tends to select fault revealing test cases more efficiently than in the case where random selection is used.     

Supermolecular structure of diacetate fibres which have been modified with polytetrafluoroethylene

Conclusions It has been found that the degree and character of structural transformations of acetate fibre in the process of graft polymerization of PTFE depend on the content of grafted-on polymer.The grafted-on polymer is localized both on the surface and also in free spaces inside the fibre.Translated from Khimicheskie Volokna, No. 3, pp. 27–29, May–June, 1988.     

Prediction of protective efficiency of corrosion-preventive compounds

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 8, pp. 31–32, August, 1990.