This paper describes the characterization of commercially available plastic scintillation detectors to be used as an active shield or veto system to reduce the neutron background resulting from ...atmospheric muon interactions in low-level nuclear waste assay systems. The shield consists of an array of scintillation detectors surrounding a neutron detection system. Scintillation detectors with different thicknesses are characterized for their response to gamma rays, neutrons, and muons. Response functions to gamma rays were determined and measured in the energy range from 0.6 MeV to 6.0 MeV using radionuclide sources. Neutron response functions were derived from results of time-of-flight measurements at the Van de Graaff accelerator of the INFN Legnaro and from measurements with quasi mono-energetic neutron beams produced at the Van de Graaff accelerator of the JRC Geel. From these data, the light output and resolution functions for protons and electrons were derived. The response to muons was verified by background measurements, i.e. without the presence of any neutron or gamma source. It was found that the muon peak is more pronounced when the detectors are placed horizontally. The results indicate that a scintillator with a minimum thickness of 20 mm is needed to separate events due to atmospheric muons from natural gamma ray background, and contributions due to neutron production in nuclear waste based on only the total energy deposition in the detector. In addition, it was shown that muons can be identified with a coincidence pattern when the detectors are stacked. The effectiveness of the proposed system was demonstrated based on muon induced spallation reactions in a lead sample.
The Robinson Projection is the most preferred World map projection in the atlas cartography. There are no analytical formulas except Robinson's look-up table for this projection. This deficiency has ...led a number of requests for the plotting formulas and cartographers have studied to derive analytical equations using different algorithms. In these works, different interpolation algorithms are applied to Robinson's table values and solutions are presented including some critics about the deformations on this projection. In this study, a summary of these computation algorithms is collected. The multiquadric interpolation method is suggested and applied to the Robinson's tabular coordinates. A series of numerical evaluations are presented then for the controversies and for comparison between these computation algorithms.
Ginzburg IV projection, which is also known as the CNIIGAiK 1939-1949 projection, is a modified polyconic projection that was preferred in the old USSR for mapping the whole world. There exist no ...mathematical equations which define the projection. In the Russian literature, the plane coordinates belonging to a given geographical latitude and longitude are given on tables in 10° interval. In this study, the fuzzy logic method is suggested for modelling geographical grids which are defined only with tabular coordinates, such as in the Ginzburg IV projection.
Coordinate transformations refer to mathematical processing that enables overlay of digital maps that use different coordinate reference systems, that is, map projections. The transformation from ...geographical to map (plane) coordinates is the conventional practice in cartography, which is called forward transformation. The inverse transformation, which yields geographical coordinates from map coordinates, is a more recent development, due to the need for transformation between different map projections, especially in geographic information systems (GIS). The combination of the inverse and forward transformation from one projection to another, which may be called grid-on-grid or map-to-map transformation, can be necessary for some custom applications in GIS and in automated cartography. Many different approximation algorithms can be used for this problem on desktop computers. In this paper a new local transformation method called a non-Sibsonian transformation, which uses non-Sibson local coordinates, is suggested for map-to-map transformation or for improving geometrical accuracy of scanned maps. A case study is performed using the Lambert conformal conic projection and is presented with results.
Celotno besedilo
Dostopno za:
DOBA, FGGLJ, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The map projection problem involves transforming the graticule of meridians and parallels of a sphere onto a plane using a specified mathematical method according to certain conditions. Map ...projection transformations are a research field dealing with the method of transforming one kind of map projection coordinates to another. The conversion from geographical to plane coordinates is the normal practice in cartography, which is called forward transformation. The inverse transformation, which yields geographical coordinates from map coordinates, is a more recent development due to the need for transformation between different map projections, especially in Geographic Information Systems (GIS). The direct inverse equations for most of the map projections are already in existence, but for the projections, which have complex functions for forward transformation, defining the inverse projection is not easy. This paper describes an iteration algorithm to derive the inverse equations of the Winkel tripel projection using the Newton–Raphson iteration method.
Celotno besedilo
Dostopno za:
DOBA, FGGLJ, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
