This work analyses theoretically, technologically and practically a class of low-loss single-mode optical fibers with ring refractive index profile. The fibers are considered for long distance signal transmission as well as photonic signal processing. Trunk transmission, ring index fibers have shifted and flattened dispersion characteristics and much larger effective area as compared with stand...

We describe a sequential universal data compression procedure for binary tree sources that performs the " double mixture. " Using a context tree, this method weights in an efficient recursive way the coding distributions corresponding to all bounded memory tree sources, and achieves a desirable coding distribution for tree sources with an unknown model and unknown parameters. Computational and ...

We attempt to get a physical insight into grain alignment processes by studying basic properties of radiative torques (RATs). For this purpose we consider a simple toy model of a helical grain that reproduces well the basic features of RATs. The model grain consists of a spheroidal body with a mirror attached at an angle to it. Being very simple, the model allows analytical description of RATs ...

Convex polytopes are fundamental geometric objects that have been investigated since antiquity. The beauty of their theory is nowadays complemented by their importance for many other mathematical subjects, ranging from integration theory, algebraic topology, and algebraic geometry to linear and combinatorial optimization. In this chapter we try to give a short introduction, provide a sketch of ...

In this article we introduce some definitions concerning measurable functions and prove related properties. In this paper k is a natural number, r is a real number, i is an integer, and q is a rational number. The subset Z − of R is defined by: (Def. 1) r ∈ Z − iff there exists k such that r = −k. Let us note that Z − is non empty. The following three propositions are true: (1) N ≈ Z −. Z is a ...

We complete the initial study of jumping finite automata, which was started in a former article of Meduna and Zemek [6]. The open questions about basic closure properties are solved. Besides this, we correct erroneous results presented in the article. Finally, we point out important relations between jumping finite automata and some other models studied in the literature.

introduction: solar net radiation (rn) is one of the most important component which influences soil heat flux, evapotranspiration rate and hydrological cycle. this parameter (rn) is measured based on the difference between downward and upward shortwave (sw) and longwave (lw) irradiances reaching the earth’s surface. field measurements of rn are scarce, expensive and difficult due to the instrum...

Abstract We propose a novel one-dimensional radiation distribution sensing method using an optical fiber sensor based on wavelength spectrum unfolding for the application in measurement of high dose rate hot spots inside Fukushima Daiichi nuclear power station (FDNPS) buildings. The proposed estimates incident position to by output from edge premise that attenuation length light along depends w...

The main results of the EC project ‘Genomic instability and radiation-induced cancer’ (RADINSTAB) are reviewed and the potential implications of genomic instability and bystander effect for risk assessment and radiation protection discussed. A basic paradigm in radiobiology is that, after exposure to ionising radiation, the deposition of energy in the cell nucleus and the resulting damage to DN...

Background: It has recently been shown that the particle size of materials used for radiation shielding can affect the magnitude of radiation attenuation. Over the past years, application of nano-structured materials in radiation shielding has attracted attention world-wide. The purpose of this study was to investigate the shielding properties of the lead-free shields containing micro and nano-...