392 research outputs found
КОМБИНИРОВАННАЯ ИМИТАЦИОННО-АНАЛИТИЧЕСКАЯ МОДЕЛЬ ПРОПУСКНОЙ СПОСОБНОСТИ АЭРОДРОМНОЙ ВОЗДУШНОЙ ЗОНЫ
An approach to the problem of estimating an aerodrome airspace capacity based on the idea of airspace «quantization» and transition to discrete time while imposing restrictions on the filling of quantum states by aircrafts has been developed in this paper. It is shown that such a formalism can significantly reduce the complexity of aircrafts movement simulation in the airfield zone, to take into account the restrictions imposed on the aerodrome airspace capacity by intersections of arrival and departure routes. The paper presents the results of the simulation experiment, illustrating the dependence of the aerodrome airspace capacity upon the number of aircraft routes intersections, [email protected].В работе развивается подход к задаче оценки пропускной способности воздушной аэродромной зоны, основанный на идее «квантования» воздушного пространства, перехода в дискретное время при наложении ограничений на заполнение квантовых состояний воздушными судами [4-6]. Показано, что такой формализм позволяет существенно снизить трудоемкость задачи имитационного моделирования движения воздушных судов в аэродромной зоне, учесть ограничения, накладываемые на ее пропускную способность пересечениями маршрутов прилета и вылета ВС. В статье приводятся результаты проведенного имитационного эксперимента, иллюстрирующие зависимость пропускной способности зоны от количества пересечений маршрутов воздушных судов
Embedded systems with remote access in education
Предложен новый метод организации удаленного доступа к лабораторным установкам на основе использования языка РНР для управления через СОМ-порт.It is proposed a new method of remote access to laboratory apparatus with use of language PHP for management through Com port
Аппаратный и программный интерфейс для оптических исследований на основе ПЗС-линейки
The report shows how to solve problems updating experimental laboratory facilities for the study of optical phenomena related to the use of new computers and operating systems.В докладе показано, как решать проблемы обновления экспериментальных лабораторных комплексов по исследованию оптических явлений, связанные с использованием новых компьютеров и операционных систем
First atom lifetime and scattering length measurements
The results of a search for hydrogen-like atoms consisting of
mesons are presented. Evidence for atom production
by 24 GeV/c protons from CERN PS interacting with a nickel target has been seen
in terms of characteristic pairs from their breakup in the same target
() and from Coulomb final state interaction (). Using
these results the analysis yields a first value for the atom lifetime
of fs and a first model-independent measurement of
the S-wave isospin-odd scattering length
( for isospin ).Comment: 14 pages, 8 figure
Determination of scattering lengths from measurement of atom lifetime
The DIRAC experiment at CERN has achieved a sizeable production of
atoms and has significantly improved the precision on its lifetime
determination. From a sample of 21227 atomic pairs, a 4% measurement of the
S-wave scattering length difference
has been attained, providing an important test of Chiral Perturbation Theory.Comment: 6 pages, 6 figure
Detection of atoms with the DIRAC spectrometer at CERN
The goal of the DIRAC experiment at CERN is to measure with high precision
the lifetime of the atom (), which is of order
s, and thus to determine the s-wave -scattering
lengths difference . atoms are detected through the
characteristic features of pairs from the atom break-up
(ionization) in the target. We report on a first high statistics atomic data
sample obtained from p Ni interactions at 24 GeV/ proton momentum and
present the methods to separate the signal from the background.Comment: 19 pages, 12 figures, 1 tabl
Comprehensive analysis of the chromatin landscape in Drosophila melanogaster.
Chromatin is composed of DNA and a variety of modified histones and non-histone proteins, which have an impact on cell differentiation, gene regulation and other key cellular processes. Here we present a genome-wide chromatin landscape for Drosophila melanogaster based on eighteen histone modifications, summarized by nine prevalent combinatorial patterns. Integrative analysis with other data (non-histone chromatin proteins, DNase I hypersensitivity, GRO-Seq reads produced by engaged polymerase, short/long RNA products) reveals discrete characteristics of chromosomes, genes, regulatory elements and other functional domains. We find that active genes display distinct chromatin signatures that are correlated with disparate gene lengths, exon patterns, regulatory functions and genomic contexts. We also demonstrate a diversity of signatures among Polycomb targets that include a subset with paused polymerase. This systematic profiling and integrative analysis of chromatin signatures provides insights into how genomic elements are regulated, and will serve as a resource for future experimental investigations of genome structure and function
Evidence for -atoms with DIRAC
We present evidence for the first observation of electromagnetically bound
-pairs (-atoms) with the DIRAC experiment at the CERN-PS.
The -atoms are produced by the 24 GeV/c proton beam in a thin Pt-target
and the and -mesons from the atom dissociation are analyzed in
a two-arm magnetic spectrometer. The observed enhancement at low relative
momentum corresponds to the production of 173 54 -atoms. The mean
life of -atoms is related to the s-wave -scattering lengths, the
measurement of which is the goal of the experiment. From these first data we
derive a lower limit for the mean life of 0.8 fs at 90% confidence level.Comment: 15 pages, 9 figure
New data on OZI rule violation in bar{p}p annihilation at rest
The results of a measurement of the ratio R = Y(phi pi+ pi-) / Y(omega pi+
pi-) for antiproton annihilation at rest in a gaseous and in a liquid hydrogen
target are presented. It was found that the value of this ratio increases with
the decreasing of the dipion mass, which demonstrates the difference in the phi
and omega production mechanisms. An indication on the momentum transfer
dependence of the apparent OZI rule violation for phi production from the 3S1
initial state was found.Comment: 11 pages, 3 PostScript figures, submitted to Physics Letter
The bound mu+ mu- system
We consider the hyperfine structure, the atomic spectrum and the decay
channels of the bound mu+ mu- system (dimuonium). The annihilation lifetimes of
low-lying atomic states of the system lie in the nanosecond range range. The
decay rates could be measured by detection of the decay products (high energy
photons or electron-positron pairs). The hyperfine structure splitting of the
dimuonic system and its decay rate are influenced by electronic vacuum
polarization effects in the far time-like asymptotic region. This constitutes a
previously unexplored kinematic regime. We evaluate next--to-leading order
radiative corrections to the decay rate of low-lying atomic states. We also
obtain order alpha^5 corrections to the hyperfine splitting of the 1S and 2S
levels.Comment: 10 figures (eps format) attached, Scheduled tentatively by PRA for
Nov/Dec 199
- …