Law,liability and expert systems

This paper examines some of the possible legal implications of the production, marketing and use of expert systems. The relevance of a legally useful definition of expert systems, comprising systems designed for use both by laymen and professionals, is related to the distinctions inherent in the legal doctrine underlying provision of goods and provision of services. The liability of the sellers and users of, and contributors to, expert systems are examined in terms of professional malpractice as well as product liability. A recurring theme indicates that legislators may be inclined to restrict possibilities of liability suits in order to avoid disincentives to the creation of expert systems.     

Optimal characteristic polynomials for digital multistep pseudorandom numbers

The digital multistep method generates uniform pseudorandom numbers by transforming sequences of integers obtained by multistep recursions. The statistical independence properties of these pseudorandom numbers depend on the characteristic polynomial of the recursion. We describe a method of calculating characteristic polynomials that are optimal with respect to statistical independence of pairs of successive pseudorandom numbers. Tables of such optimal characteristic polynomials for degrees ≤64 are included.     

Biaxiale Ermüdung reibrührgeschweißter Strukturelemente

Biaxial fatigue of friction stir welded stiffened panels Within the framework of the European WelAir project, cruciform specimens made from stiffening FSW overlap joints were fatigued in the DLR biaxial test rig. To resemble the loading situation of pressurized fuselage structures, proportional loading without any phase shift, but with different load ratios λ between the loading components in both directions was applied.Natural crack initiation and subsequent crack growth were governed by the stiffness gradient caused by introducing the stringer. Cracks initiated and propagated at run‐in and run‐out locations in a direction perpendicular to the weld seam. The shortest fatigue life was observed for uniaxial loading in welding direction (λ = 0). An additional stress component perpendicular to the joint line (λ > 0) resulted in a higher number of cycles to failure. Similar to single stringer panels, increasing the load ratio also increased the number of cycles to failure for FSW clip‐stringer structural members, but additionally gives a different location of the fatal crack.     

Der PC in zehn Jahren und seine Auswirkungen auf die Gesellschaft

In this article it is argued that in ten years’ time personal computers as we know them now won’t exist anymore — all their functions will by then be integrated in mobiles which will be our steady companions. As such, mobiles will change our lives to an enormous extent. Technology as well as consequences will be discussed in this paper.     

Growth of GaAs on polycrystalline silicon-on-insulator

The growth of GaAs on polycrystalline silicon-on-insulator (SOI) substrates by metal organic vapor phase epitaxy using a two-step growth process was studied in this work. We have compared the variation of the growth temperature and the thickness of the initial GaAs epilayer in the structures grown on polycrystalline SOI to ones grown on SOI and epi-Si. Structural properties were studied using high-resolution X-ray diffraction (XRD). The growth temperature had a strong effect on the FWHM of the (0 0 4) XRD curve in structures grown on SOI and epi-Si. In the case of polycrystalline SOI the effect was not as strong. Optical properties of the samples in which the optically active layer consisted of self-organized In_0.5Ga_0.5As quantum dots were investigated by photoluminescence measurements. The photoluminescence intensity from structures grown on polycrystalline SOI was comparable to that from structures grown on SOI and epi-Si.