Diagnosis of cavitation in centrifugal pumps.

The thesis introduces an algorithmic framework for diagnosis of cavitation in centrifugal pumps, founded upon methods of artificial intelligence. The framework forms a blueprint for a wide range of on-line condition monitoring systems with cavitation diagnosis capability. It relies on information provided by a single acceleration sensor mounted on casing of the monitored pump. The signal provided by the sensor is evaluated by an artificial neural network classifier. Adaptation of the classifier to a specific pump type is carried out by means of a supervised learning algorithm. Furthermore, a complete cavitation diagnosis application methodology, developed by the author, is presented in the thesis. It deals with issues of implementation of cavitation diagnosis to a variety of centrifugal pumps employed in industrial environment.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

Beyond Balassa-Samuelson: Real appreciation in tradables in transition countries

We decompose real appreciation in tradables derived from producer price indexes in three Central European countries between the pricing-to-market component (disparity) and the local relative price component (the substitution ratio). Appreciation is only partially explained by local relative prices. The rest is absorbed by disparity, depending on the size of the no-arbitrage band. The observed disparity fluctuates in a wider band for differentiated products than for commodity like goods. Copyright (c) 2006 The Authors Journal compilation (c) 2006 The European Bank for Reconstruction and Development..