Average Case Analyses of List Update Algorithms, with Applications to Data Compression

We study the performance of the Timestamp (0) (TS(0)) algorithm for self-organizing sequential search on discrete memoryless sources. We demonstrate that TS(0) is better than Move-to-front on such sources, and determine performance ratios for TS(0) against the optimal off-line and static adversaries in this situation. Previous work on such sources compared on-line algorithms only with static adversaries. One practical motivation for our work is the use of the Move-to-front heuristic in various compression algorithms. Our theoretical results suggest that in many cases using TS(0) in place of Move-to-front in schemes that use the latter should improve compression. Tests using implementations on a standard corpus of test documents demonstrate that TS(0) leads to improved compression. Received December 3, 1995; revised April 5, 1997.     

Efficient Nd:YAG slab longitudinally pumped by diode lasers

An efficient scalable 1.06-μm continuous-wave (CW) Nd:YAG slab laser longitudinally pumped by diode lasers is discussed. The 809-nm diode radiation is focused into every laser channel emerging from the reflection points of the 1.06-μm beam on the coated slab surfaces. A maximum CW TEM₀₀ output power of 675 mW has been obtained at a diode pump power of 2 W resulting in a slope efficiency of 40%     

Elektronenspektroskopie für Chemische Analysen (ESCA) im industriellen Routinebetrieb

A next generation ESCA system is introduced. Easy and automated operation meet all modern industrial requirements. The System provides a new service concept which includes internet connectivity. In addition to the actual measurements, vacuum, cooling and all other important parameters are managed by the system controls. The quality of measurement results is comparable to that of dedicated research systems. Reluctance to use ESCA as a standard method for industrial testing should now belong to the past.