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Number of results: 5
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Abstract

Topography and toponymies of Dunöyane were discussed in brief. The location of Lammas Islands was considered. The author recognized it as a trace of discovery of Dunöyane by Hudson in 1607. Historical data on human activity in this region was presented with a closer look at the murder of 10 Russians in 1819 and at Norwegian economic exploitation in the 19th and 20th centuries.
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Abstract

Archaeological investigations were carried out on Sörkappland, the results together with literature data permitted to draw the past distribution of walruses at South Spitsbergen. Recent observations of walruses and marine biological survey indicate good perspectives for the recolonisation of investigated area by walrus population from East Svalbard region.
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Abstract

Improvements of modern manufacturing techniques implies more efficient production but also new challenges for coordinate metrologists. The crucial task here is a coordinate measurement accuracy assessment. It is important because according to technological requirements, measurements are useful only when they are stated with their accuracy. Currently used methods for the measurements accuracy estimation are difficult to implement and time consuming. It is therefore important to implement correct and validated methods that will also be easy to implement. The method presented in this paper is one of them. It is an on-line accuracy estimation method based on the virtual CMM idea. A model is built using a modern LaserTracer system and a common test sphere and its implementation lasts less than one day. Results obtained using the presented method are comparable to results of commonly used uncertainty estimation methods which proves its correct functioning. Its properties predispose it to be widely used both in laboratory and industrial conditions.
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Abstract

The cuboidal room acoustics field is modelled with the Fourier method. A combination of uniform, impedance boundary conditions imposed on walls is assumed, and they are expressed by absorption coefficient values. The absorption coefficient, in the full range of its values in the discrete form, is considered. With above assumptions, the formula for a rough estimation of the cuboidal room acoustics is derived. This approximate formula expresses the mean sound pressure level as a function of the absorption coefficient, frequency, and volume of the room separately. It is derived based on the least-squares approximation theory and it is a novelty in the cuboidal room acoustics. Theoretical considerations are illustrated via numerical calculations performed for the 3D acoustic problem. Quantitative results received with the help of the approximate formula may be a point of reference to the numerical calculations.
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