Modelling and measuring multilateral co-authorship in international scientific collaboration. Part II. A comparative study on the extent and change of international scientific collaboration links

The present study is focused on international collaboration in science, involving more than two countries. The authors developed a promising model to measure and analyse the extent of multilateral co-authorship links in a previous study. The model is based on a series expansion approach which relates a new indicator, the Multilateral Collaboration Index (ρ), to the share of internationally co-authored papers (f). The model was found suitable to classify both the share of international papers, as well as the extent of multilateral links through the deviations from their expectations. A comparative analysis is made of changing collaboration patterns between 1983 and 1993 for 8 selected subfields, as well as all fields combined of the most active 38 countries. As expected an intensification of international scientific collaboration was observed, especially for a number of former COMECON countries. Different types of behaviour for different countries and science subfields emerged.     

On the Choice of Regression in Linear Calibration. Comments on a paper by R. G. Krutchkoff

In a paper by R. G. Krutchkoff, “Classical and Inverse Regression Methods of Calibration,” two methods of Calibration are compared by means of the Monte Carlo technique. He comes to the conclusion that the inverse approach to the Calibration problem has a uniformly smaller mean square error than the classical approach. Our theoretical treatment of the problem shows that the conclusion is true only for small samples. It is shown that when more than one observation is made on y the advantage of the inverse approach is reduced. A large sample formula for the ratio of the two mean square errors is derived which mainly conforms to the result by Krutchkoff.     

J. H. Kulick, J. M. Jarem, R. G. Lindquist, S. T. Kowel, and M. W. Friends are with the Department of Electrical and Computer Engineering, University of Alabama in Huntsville, Huntsville, Alabama 35899

The development and modeling of a liquid-crystal phase grating for real-time diffractive three-dimensional displays are discussed. The system being developed, which is called the ICVision system, utilizes a number of ideas that will result in a rugged, low-power three-dimensional display offering both vertical and horizontal parallax and eventually full color. Fringing fields created between interdigitated electrodes formed on top of VLSI die will induce a diffraction pattern in a thin layer of liquid crystal that will cover the die. A detailed electrostatic and diffraction analysis of liquid-crystal phase-grating regions that will make up the final display is given here. The electrostatic analysis is developed by use of the method of moments. The diffraction analysis is developed by use of rigorous coupled-wave diffraction theory. The numerical results obtrained from the mathematical model are compared with experimental diffraction results from preliminary LCD cells that have been assembled as prototype ICVision devices.     

Comments on the article of G. S. Ioffee on the “rationalization of equations in the theory of electricity and magnetism”

Conclusion The arguments of the author of the above article in defense of the thesis on the existence of assumed internal contractions in the SI system are not convincing. Nevertheless, in our opinion it is advisable to change in GOST9867-61 the term measurement unit size to the term measurement unit dimension.Translated from Izmeritel'naya Tekhnika, No. 2, pp. 63–64, February, 1967.