Irreducible decomposition of Gaussian distributions and the spectrum of black-body radiation

It is shown that the energy of a mode of a classical chaotic field, following the continuous exponential distribution as a classical random variable, can be uniquely decomposed into a sum of its fractional part and of its integer part. The integer part is a discrete random variable (we call it Planck variable) whose distribution is just the Bose distribution yielding the Planck law of black-body radiation. The fractional part is the dark part (we call is dark variable) with a continuous distribution, which is, of course, not observed in the experiments. It is proved that the Bose distribution is infinitely divisible, and the irreducible decomposition of it is given. The Planck variable can be decomposed into an infinite sum of independent binary random variables representing the binary photons (more accurately photo-molecules or photo-multiplets) of energies 2^s*h*nu with s=0,1,2... . These binary photons follow the Fermi statistics. Consequently, the black-body radiation can be viewed as a mixture of statistically and thermodynamically independent fermion gases consisting of binary photons. The binary photons give a natural tool for the dyadic expansion of arbitrary (but not coherent) ordinary photon excitations. It is shown that the binary photons have wave-particle fluctuations of fermions. These fluctuations combine to give the wave-particle fluctuations of the original bosonic photons expressed by the Einstein fluctuation formula.Comment: 29 page

Разработка системы управления электротехнологической установкой на основе беспроводного интерфейса

Развитие микроконтроллерной техники дает возможность создать беспроводное устройство управления ЭТУ, которое позволило бы решить ряд проблем, возникающих в проводных системах, и сделало бы работу оператора более комфортной и безопасной. Объектом исследования является система беспроводного управления макетом электротехнологической установки (ЭТУ). Цель работы – разработка беспроводной системы управления макетом ЭТУ. В результате исследования была разработана работоспособная система управления ЭТУ состоящая из интерфейса управления и макета ЭТУ.The development of microcontroller technology makes it possible to create a wireless control device for an electrical installation, which would solve a number of problems arising in wired systems, and would make the operator's work more comfortable and safe. The object of the research is the system of wireless control of the layout of the electrotechnological installation of the electrotechnical installation. The purpose of the work is to develop a wireless control system for the layout of an electrotechnical installation. As a result of the study, a workable control system for an electrical installation was developed, consisting of a control interface and a model for an electrical installation

Einstein's fluctuation formula. A historical overview

A historical overview is given on the basic results which appeared by the year 1926 concerning Einstein's fluctuation formula of black-body radiation, in the context of light-quanta and wave-particle duality. On the basis of the original publications (from Planck's derivation of the black-body spectrum and Einstein's introduction of the photons up to the results of Born, Heisenberg and Jordan on the quantization of a continuum) a comparative study is presented on the first line of thoughts that led to the concept of quanta. The nature of the particle-like fluctuations and the wave-like fluctuations are analysed by using several approaches. With the help of the classical probability theory, it is shown that the infinite divisibility of the Bose distribution leads to the new concept of classical poissonian photo-multiplets or to the binary photo-multiplets of fermionic character. As an application, Einstein's fluctuation formula is derived as a sum of fermion type fluctuations of the binary photo-multiplets.Comment: 34 page

A review of Monte Carlo simulations of polymers with PERM

In this review, we describe applications of the pruned-enriched Rosenbluth method (PERM), a sequential Monte Carlo algorithm with resampling, to various problems in polymer physics. PERM produces samples according to any given prescribed weight distribution, by growing configurations step by step with controlled bias, and correcting "bad" configurations by "population control". The latter is implemented, in contrast to other population based algorithms like e.g. genetic algorithms, by depth-first recursion which avoids storing all members of the population at the same time in computer memory. The problems we discuss all concern single polymers (with one exception), but under various conditions: Homopolymers in good solvents and at the $\Theta$ point, semi-stiff polymers, polymers in confining geometries, stretched polymers undergoing a forced globule-linear transition, star polymers, bottle brushes, lattice animals as a model for randomly branched polymers, DNA melting, and finally -- as the only system at low temperatures, lattice heteropolymers as simple models for protein folding. PERM is for some of these problems the method of choice, but it can also fail. We discuss how to recognize when a result is reliable, and we discuss also some types of bias that can be crucial in guiding the growth into the right directions.Comment: 29 pages, 26 figures, to be published in J. Stat. Phys. (2011

SFB 880: aeroacoustic research for low noise take-off and landing

This paper gives an overview about prediction capabilities and the development of noise reduction technologies appropriate to reduce high lift noise and propeller noise radiation for future low noise transport aircraft with short take-off and landing capabilities. The work is embedded in the collaborative research centre SFB 880 in Braunschweig, Germany. Results are presented from all the acoustics related projects of SFB 880 which cover the aeroacoustic simulation of the effect of flow permeable materials, the characterization, development, manufacturing and operation of (porous) materials especially tailored to aeroacoustics, new propeller arrangements for minimum exterior noise due to acoustic shielding as well as the prediction of vibration excitation of aircraft structures, reduced by porous materials

Handling of Non-Periodic Contra Rotating Open Rotor Data

In this contribution, we present two different concepts to handle the non-periodic nature of Contra Rotating Open Rotor (CROR) if the front and the aft rotor rotate with a slightly different rotational speed. The first procedure that is presented consists of a correction matrix applied to the source data used in the DLR FWH-code APSIM+. For periodic data the correction matrix reduces to the identity matrix, thereby recovering the standard Fourier transformation. The second method is based on the Vanicek approximation, and consists of a successive least-square approximation of non-periodic data. The developed methods are tested with artificially generated data, illustrating the ability to accurately representing non-periodic data. A comparison between the two methods shows that the first method is more accurate than the Vanicek approximation. Preliminary results on actual non-periodic CROR data reveals the influence of the non-periodic correction as compared to uncorrected data, i.e., differences ranging up to 10 dB are seen for the considered cases

St. John's Daily Star, 1920-12-15

The St. John's Daily Star was published daily except Sunday between 17 April 1915 - 23 July 1921