Large band simulation of the wind speed for real time wind turbine simulators

In this paper, the authors propose two modeling procedures for wind speed simulation. These procedures could be implemented on the structure of a wind turbine simulator during studies concerning stand-alone or hybrid wind systems. The evolution of a horizontal wind speed has been synthesized taking into account two components. The medium- and long-term component is described by a power spectrum associated to a specific site. The turbulence component is assumed to be dependent on the medium- and long-term wind speed evolution. It is considered as a nonstationary process. Two simulation methods for this component, using rational and nonrational filters are proposed. In both procedures, the turbulence model is defined by two parameters, which are either obtained experimentally, or adopted a priori, according to information from the considered site. Numerical results and implementation aspects are also discussed.     

Negotiation support systems: roots, progress and needs

Abstract. This paper identifies game theories and social behavior science as important roots for negotiation support systems (NSS) research. As these are not typically cited in the NSS literature, summary reviews of them are provided with indications of their relevance to NSS study. On the other hand, neither offers a sufficiently general-purpose formal model of negotiation that could serve as a backbone for NSS research. A survey of that research is provided, indicating that prugress to date has been somewhat eclectic and devoid of such a model. Our central contention is that a theoretical foundation for NSS study is much needed. Desirable characteristics of a suitable negotiation model are identified as guidance for future research that will aim to devise (and subsequently apply and test) such a model.     

Shape optimization of an elastic thin shell under various criteria

The aim of this study is to propose a methodology for optimizing the shape (middle surface and thickness) of an elastic general thin shell (i) under different criteria: minimization of the weight, of the stresses, of the strain energy; (ii) with or without constraints: if any, these can be bounds on some displacements, on some stresses.This is a common problem in real life, the engineer has to construct structures which have the best mechanical behaviour and the best price; the price is often proportional to the weight of the structure.In this paper only the general continuous formulation of the problems is considered. From this strong basis a corresponding discrete formulation and some industrial applications will subsequently be developed.     

International coordination of operational instruments on the NASAand ESA space station polar orbiting platforms

The roles played by the National Oceanic and Atmospheric Administration (NOAA) and the international community in coordinating plans to fly operational instruments on NOAA polar orbiting satellites are discussed, as is how this coordination has assisted in the planning for the flight of similar instruments on the proposed NASA and ESA polar orbiting platforms in the mid-to-late-1990s. Details on the operational sensor complements on the polar platforms are provided     

Applications of an Infrared Imager for Determining Temperature Fields in Gas Flows

A device containing a temperature converter with an infrared camera is described. Its application allows one to instantly measure the temperature field of a gas flow in regions of arbitrary sizes.     

Obtaining high defect coverage for frequency-dependent defects in complex ASICs

Structured delay tests have been around for years, but how effectively do they identify defective silicon, even at reduced frequency? How much overkill is associated with their use? The authors present data from industrial circuits aimed at these and other aspects of speed testing.     

Changes of the corneal endothelium after ultraviolet-B exposure in previously photokeratectomized eyes

The photorefractive effect of excimer lasers is based on an interaction between the 193-nm ultraviolet-C laser beam and the stromal chromophore molecules. Recently, in some patients an increase of subepithelial haze and a regression of refractive effect has been observed following suntanning (UV-B exposure). The aim of the study was to find out the possible endothelial damage caused by photoablation with increasing depth and the effect of subsequent UV-B exposure on previously photokeratactomized eyes. Altogether 12 chinchilla rabbits were treated. Four animals received a -5.0 D PRK; four animals a -15.0 D PRK and four animals a -30.0 D PRK treatment. The endothelial average number, size and variation were determined two weeks post-PRK. Three weeks following PRK, a half of the animals received a 1 J/cm2 ultraviolet-B radiation in a constant dermatological UV-chamber. The endothelial morphology was measured the same way with automated specular microscopy two weeks after UV-B irradiation. After PRK treatment there was no statistically demonstrable change in endothelial morphology. On the other hand, after UV-B radiation all eyes showed a decrease in endothelial number and an increase in size and variation. The ratio of hexagonality decreased, and endothelial rosette formation appeared. The early morphological changes resembled the physiological aging changes. Conditions (deep stromal photoablation, cumulative effect of suntanning or solarium treatments) may exaggerate the physiological aging processes leading to subsequent pleomorphism, polymegatism and cell loss. This may accelerate corneal dysfunction.     

Heat transfer from a stretching sheet with uniform suction and blowing

Summary The conjugate problem of heat transfer from an accelerating surface in presence of suction and blowing has been solved analytically. The effects of different parameters on cooling of the surface have been discussed.With 3 Figures