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Sequel of no. 4/83, p. 24 Not many national associations hold conventions in countries other than their own. In Northwest Europe it is unlikely that any country is a net recipient of national conventions from elsewhere in Europe. In fact, there is likely to be some small ‘leakage’ of national association conventions to destinations in the Mediterranean or further afield. However, Northwest Europe (particularly the U.K. and Ireland) receives a small number of North American association conventions. Based on the available data this may amount to some 25 large conventions yearly.

In the paper the optimization procedure of a direct current motor with a hybrid excitation has been presented. The excitation system consists of a shunt field winding disposed around field pole and permanent magnet, both acting in parallel. The field distribution in motor for various magnet and field pole dimensions has been determined using finite element method. The flux linkage with the armature winding has been computed. Demagnetizing effect of armature current was taken into account. The optimal permanent magnet and the field pole dimensions, ensuring minimum total cost of purchase and work during assumed period of time were calculated. Motor characteristics e.g. rated torque, rated current, speed regulation limit were used as constraints. In worked up algorithm and computer program Carroll internal penalty function method was used. Some basic suggestions tor design of optimal hybrid excited dc motors with parallel permanent magnet and electromagnetic excitation are given.

I‐V characteristics of GaAs n‐i‐n structures are calculated by considering impact ionization of carriers. Impact ionization at reverse‐biased n‐i junction becomes a cause of steep current rise when an acceptor density in the i‐layer is high. It is shown that an optimum acceptor density exists to keep a good isolation. Photoconduction transients of GaAs n‐i‐n structures are also simulated, and are shown to be strongly affected by existence of n‐i junctions.

In the course of development of human communities towards industrially advanced societies of today, there have been changes not only in economic conditions in the majority of fields of human activity but also in the ways of providing for food, which went hand in hand with changes in living conditions. Large‐scale industrial production has brought about major changes in the way of life of the population. The development of industrial agglomerations results in a growing number of city dwellers, most of whom have no chance of producing foodstuffs of their own in kind. The distance between residential and industrial areas has been growing, the number of employed women has risen considerably. These are but a few factors affecting the way of boarding, particularly in households.

The paper deals with the method of the stray losses calculation in single‐sided linear induction motors. The stray losses produced by the higher space harmonics of the primary winding MMF and by the primary slots have been discussed.

The commercial practice of tourism avails itself of a whole range of classical methods of research into market, its dispersion and trends, starting with statistics and ending up with public opinion polls. The pattern and volume of tourism demand as well as its principal trends may be compared on the basis of international statistics that are more or less uniform. However, not even more detailed statistical observations are adequate for the formulation of long‐term marketing strategy of the given country.

12,2 Millionen Bundesbürger sind über 60 Jahre alt. Im Jahre 2000 werden es bereits 14 Millionen sein. Kein Wunder also, dass die Senioren für viele Wirtschaftszweige immer interessanter werden. Dies gilt auch für die Tourismusbranche, die mit der wachsenden Reisefreude der älteren Generation rechnen kann. Im vorliegenden Beitrag werden ausgewählte Ergebnisse einer Studie wiedergegeben, die das Institut für Freizeit‐ und Tourismusberatung aus Ettlingen Anfang des Jahres gemacht hatte.

The calculation of quasistationary magnetic fields and electrostatic fields of several objects is presented in the paper. In the range of the magnetic fields of coils and transformer systems parallelepiped calculation regions are assumed. In the range of electrostatic fields analysis of the field in tanks of different shape storing inflammable liquids was undertaken. Fast subroutines using finite differences [FDM] to calculate the field were employed. These subroutines are based on the Fast Fourier Transform (FFT).

The M300/IBM PC Users Group is rapidly gaining new members and has been offered a Bulletin Board in Des Moines, IA for its use. What is needed now are persons across the country who are willing to work with the administrative agent to establish a leadership structure, to plan the group's initial meeting during the Chicago 1985 ALA conference (July 6–11), to develop the parameters of the bulletin board, to set membership criteria, to develop users group goals and objectives, to develop and lead local chapters, and to report news and activities to M300. Back issues of M300 and PC REPORT contain an application form which may be used for membership, suggesting, or reporting purposes. We particularly need persons who are willing to be officers and volunteers.

Economic effects are only one aspect of the total impact of tourism. For example, the development of a tourist industry in a particular country has varying repurcussions on the long term socio‐cultural, environmental and ecological development of the local community as a whole. This article examines the main non‐economic aspects of tourism in Greece.