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991.
We estimate the statistic characteristics and extreme deviations of the state vector components for the Ilyushin Il 96–300 systems at automatic landing. 相似文献
992.
Khokhlachev A. A. Riazantseva M. O. Rakhmanova L. S. Yermolaev Yu. I. Lodkina I. G. 《Cosmic Research》2021,59(6):415-426
Cosmic Research - We investigated variations on scales of 104–105 km and local spatial inhomogeneities in the density of protons Np, doubly ionized helium ions (α-particles) Nα, and... 相似文献
993.
E.G. Cordaro P. Venegas-Aravena D. Laroze 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(7):2290-2299
We report the existence of rapid variations in (effective) geomagnetic cutoff rigidity (Rc) between the equatorial and Antarctic zones adjacent to the Andes Mountains, revealed by the variation rate of geomagnetic cutoff rigidity (VRc) in the period 1975–2010. Our analysis is based on empirical records and theoretical models of the variations in cosmic rays and on the structure of geomagnetic fields. These have given us a different view of variations in Rc in time and space along the 70°W meridian, where secular variations in the geomagnetic field are strongly influenced by the proximity of the South Atlantic Magnetic Anomaly (SAMA), one of the most important characteristics of the terrestrial magnetic field that affects our planet, close from the equator to the 50°S parallel and from South America to South Africa. The VRc presents rapid changes in mid-latitudes where SAMA exerts its influence despite the existence of smooth changes in the geomagnetic field. This shows that these changes occur mainly in the spatial configuration, rather than in the temporal evolution of Rc. The analysis was performed using measurements from the Chilean Network of Cosmic Rays and Geomagnetism Observatories, equipped with BF-3 and latest generation He-3 neutron monitors, Fluxgate magnetometers, geomagnetic reference field (IGRF) and Tsyganenko 2001 model (just for completeness). 相似文献
994.
从工程应用角度基于IPT工作模式,建立详细初步设计阶段以电子样机、虚拟仿真技术等为手段,同步开展使用与维修保障设计分析的流程和方法。以某型飞机舵机A为实例,对建立的方法进行应用,实践表明,建立的方法适用、有效、符合工程实际。该方法的建立,将对详细初步设计阶段一级IPT成员同步开展使用与维修保障设计、分析工作提供有力的技术支撑,对提高军用飞机使用与维修保障设计水平具有重要意义。 相似文献
995.
K.G. McClements 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(4):1443-1452
Detailed in situ studies of magnetic reconnection and particle acceleration, which play a crucial role in the release and redistribution of energy in solar flares, can be performed in tokamak plasmas under conditions resembling those of the flaring solar corona. Recent measurements and modelling of fast particle production during reconnection events in the Mega-Amp Spherical Tokamak (MAST) are described. Specifically, observations in this device of electron acceleration during edge localised modes, and of both ion and electron acceleration during merging-compression plasma start-up, are presented, and possible implications of these studies for particle acceleration in flares are discussed. The results from MAST lend weight to the conjecture that large numbers of ions are accelerated to sub-MeV energies in flares. 相似文献
996.
The VIRTUAL GUARD is a general-purpose computer-based CCTV surveillance system for detecting potential criminal activity in public areas. The system monitors all activity in the surveillance area, the vast majority of which is people innocently going about their normal business. It will alarm when the observed activities of particular pedestrians and vehicles match any of the pre-defined “suspicious behaviour criteria” programmed into the system. At the same time as analysing movement behaviour, the system uses computer-controlled pan tilt zoom cameras to obtain close-up video recordings of any pedestrians and vehicles at the scene. The system can provide automatic surveillance in many different situations, from parking areas and commercial districts, to housing, recreational and transport facilities. It is particularly suited to the protection of government or commercial buildings located on city streets or other public areas where it is not possible to install perimeter fences 相似文献
997.
Sattar F. Salomonsson G. 《IEEE transactions on aerospace and electronic systems》2000,36(4):1179-1189
We suggest a method, based on the use of filter bank and higher order statistics (cumulants), for detection of transient signals. The method first uses a bandpass filter bank, which separates the spectrum of the observed signal into narrow frequency bands. Each subfilter of the filter bank is then followed by a cumulant estimator, and thereby suppressing colored noise. By selecting those subfilters that have large output energies, the filter bank can approximate the behavior of a matched filter. Moreover, no a priori information about the waveform of the signal is needed. The performance of the detector is evaluated by using a simulated signal as well as a measured signal. The presented detector is compared with the optimal matched filter detector. 相似文献
998.
999.
1000.
V. V. Zharkova K. Arzner A. O. Benz P. Browning C. Dauphin A. G. Emslie L. Fletcher E. P. Kontar G. Mann M. Onofri V. Petrosian R. Turkmani N. Vilmer L. Vlahos 《Space Science Reviews》2011,159(1-4):357-420
We review basic theoretical concepts in particle acceleration, with particular emphasis on processes likely to occur in regions of magnetic reconnection. Several new developments are discussed, including detailed studies of reconnection in three-dimensional magnetic field configurations (e.g., current sheets, collapsing traps, separatrix regions) and stochastic acceleration in a turbulent environment. Fluid, test-particle, and particle-in-cell approaches are used and results compared. While these studies show considerable promise in accounting for the various observational manifestations of solar flares, they are limited by a number of factors, mostly relating to available computational power. Not the least of these issues is the need to explicitly incorporate the electrodynamic feedback of the accelerated particles themselves on the environment in which they are accelerated. A brief prognosis for future advancement is offered. 相似文献