The performance of a combustion engine is essentially determined by the charge cycle, i.e. by the inflow of fresh air through the inlet pipe into the cylinder after a combustion cycle. The amount of air, exchanged during this process, depends on many factors, e.g. the number of revolutions per minute, the temperature, the engine and valve geometry. In order to have a tool in designing the engine one is interested in calculating this amount. The proper calculation would involve the solution of three-dimensional hydrodynamical equations governing the gas flow including chemical reactions in a complicated geometry, consisting of the cylinder, valves, inlet and outlet pipe. Since this is clearly too ambitious, we consider a simplified model.
Identifikation von Amplituden und Phasensprüngen im Intensitätsverlauf eines Nd-Yag Festkörperlasers
(1987)
Fleeces made from artificial fabric are the basic material for many products, ranging from carpets to napkins. Itturns out that their quality is determined by the distribution of the fibres, which can be measured eithter by the optical transmission properties or by the thickness of the material. In both cases one obtains a 2-dimensional signal and one would like to have an objective quality criterion, based on a suitable analysis of these data, which, moreover, can be automated.; In this paper we propose a solution to this problem, based on multiresolution techniques, which have been developed in image analysis through the last few years. Moreover, we use these techniques to investigate fractal properties of the textures.