The Measurement of Fundamental Constants (Metrology) and Its Effect on Scientific and Technical Progress
It is perhaps appropriate that in this year 1975, which marks the centenary of the Systeme Metrique and that of the Bureau International des Poids et Mesures, scientific activity in the field of Metrology appears to be flourishing. This is witnessed on the one hand by the number, range and quality of the contributions to this Symposium and, on the other, by the importance which most of the 44 Governments affiliated to the BIPM attach both to their Basic Laboratories and to the network of technical centers engaged in developing measuring methods and in disseminating their results to all levels of the various branches of industry. Should this state of affairs be considered a happy but ephemeral stage in the march of science, or does it represent a tendency of fundamental importance in the evolution of science and technology ? Enough is now known about the history of civilization for us to affirm that, even since the Renaissance, Metrology has payed an ever greater part in both scientific and civic activities.
Detection of very weak magnetic fields (10−9gauss) by 87Rb zero-field level crossing resonances
Zero-field level crossing resonances have been observed on the ground state of 87Rb. The width, a few microgauss, and the signal to noise ratio, about 2.5 × 103, allow the measurement of 10−9 gauss fields.
Transformation from availability expression to failure frequency expression
The problem of computing the system's Failure Frequency is reduced to the problem of computing its Availability. This is performed by a transformation operator. However, the existing transformation operator is not practical because its transformation time increases exponentially with system size. To overcome this difficulty, this paper proposes a new method of transforming the Availability expression of a system into the corresponding Failure Frequency expression of the system. This method is based on a matrix approach using a 2 /spl times/ 2 matrix consisting of 0, Availability, and Failure Frequency in an appropriate manner. This transformation also enables algorithms for computing the Availability of a system to be transformed into algorithms for computing its Failure Frequency by replacing parameters and operations with matrix parameters and operations. The computation time after transformation is linear with respect to the original Availability algorithm. This implies that the problems of computing other well-known reliability measures including, Availability, Unavailability, MTBF, MTTR, MCT, Failure Rate, Failure Rate, and Failure Frequency, are reduced to only the Availability computation problem.