The existence of a global time is often taken for granted but should instead be considered as a matter of investigation. By using the tools of global Lorentzian geometry I prove that, under physically reasonable conditions, the impossibility of finding a global time implies the singularity of spacetime.

Innovation in infant disciplines occurs most rapidly and successfully when a large number of small groups proceed independently under the motivation of market opportunity. In a few years, a substantial fraction of the engineering work force will have a working knowledge of LSI design. At the same time, fabrication areas are becoming more and more capital intensive. What is needed is a clean, st...

Teleradiology consists of a set of added-value telematic services, implemented over an advanced telecommunications infrastructure and supported by different information technologies and related applications. The main goal of teleradiology is to provide different levels of support for remote diagnostic imaging procedures. This paper considers technological advances in this important area, includ...

Introduction The resurgence of U.S. international competitiveness on the basis of its relative strength in the new leading sectors – computers and other information industries – has brought about a debate on adopting the U.S. model of business and industrial institutions among firms and governments in other countries. The United States is currently the most successful country in the world in ad...

Peter the Great brought technological enlightenment to Russia. In his lifetime, two special schools for training engineers were established, the Engineering School in 1700, and the Mathematical-Navigation School in 1701. Peter the Great introduced engineering training into other institutions as well, not only into the Naval Academy, but also regimental schools and even religious colleges. (See ...

g/u(1) d parafermions from constrained WZNW theories. Abstract The conformal field theory based on the g/u(1) d coset construction is treated as the WZNW theory for the affine Lie algebrâ g with the constrainedû(1) d subalgebra.Using a modification of the generalized canonical quantization method generators and primary fields of an extended symmetry algebra are found for arbitrary d.