Geiger-counter apparatus in which several counters may be placed in any position relative to each other is described. A circular arrangement of counters to give a counting rate approximately independent of the position of a so urce near the center of the circle is discussed. The relation of the I osition of the source to the counting rate of a single Geiger counter is discus ed. A method of cal...

Nowadays, there are two types of sensors to detect the low luminous flux, PMT (Photomultiplier Tube) and Geiger-APD (Geiger Avalanche Photodiode). The domain of Geiger-APD has reached an advanced development in the last years. The basic idea of this structure consists in polarizing an APD in Geiger-mode by applying a voltage beyond its breakdown voltage. In this case of polarization, the APD is...

It makes no sense to extract features at pixel level as the image is noisy and the discretization/quantization introduces artifacts. The minimum resolution in which we can look an image is an order of magnitude higher than a pixel, i.e., it is a few pixels, say 10 pixels. In an image there are various intensity discontinuities, and these are important information to preserve. Thus, when we are ...

SUMMARY GEIGER is a new software package, written in the R language, to describe evolutionary radiations. GEIGER can carry out simulations, parameter estimation and statistical hypothesis testing. Additionally, GEIGER's simulation algorithms can be used to analyze the statistical power of comparative approaches. AVAILABILITY This open source software is written entirely in the R language and ...

Although now over 100 years old, the classification of climate originally formulated by Wladimir Köppen and modified by his collaborators and successors, is still in widespread use. It is widely used in teaching school and undergraduate courses on climate. It is also still in regular use by researchers across a range of disciplines as a basis for climatic regionalisation of variables and for as...