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41.
The influence of geometry and operating conditions of the centrifugal compressor stage on the radial gas force is determined
on the basis of the theoretical method and calculation program using experimental boundary conditions. 相似文献
42.
知识库是进行各种自然语言处理任务不可或缺的一项基础性的资源。而目前知识库的构建还是一个难点问题,尤其是以自动方式构建复杂的领域性知识库系统的研究还处于探索阶段。本文提出一种基于实体-属性框架的领域知识库自动构建方法,致力于利用航空百科辞典的信息自动获取术语之间的上下位关系及部分实体属性关系,其中,基于多策略的上下位关系术语对提取融合了后缀子串匹配、模板自动构建、实质提取三种方法,分别考虑了辞典中反映上下位关系的不同信息。其中模板自动构建方法,在无需人工标注语料的情况下获得了比较好的效果。属性提取部分采用了以人工标注语料为前提的模板匹配方法。实验表明,本文系统对术语上下位关系抽取的F值达到76.01%,对各个属性的抽取也达到了75%以上。 相似文献
43.
The results of the interplanetary scintillation observations performed in the period of the maximum of solar activity from April 2013 to April 2014 on the BSA LPI radio telescope at the frequency 111MHz are presented. Fluctuations of the radio emission flux were recorded round the clock for all sources with a scintillating flux of more than 0.2 Jy falling in a strip of sky with a width of 50° over declinations corresponding to a 96-beam directional pattern of the radio telescope. The total number of sources observed during the day reaches 5000. The processing of the observational data was carried out on the assumption that a set of scintillating sources represents a homogeneous statistical ensemble. Daily two-dimensional maps of the distribution of the level of scintillations, whose analysis shows the strong nonstationarity and large-scale irregularity of the spatial distribution of solar wind parameters, were constructed. According to maps of the distribution of the level of scintillations averaged over monthly intervals, the global structure of the distribution of the solar wind was investigated in the period of the maximum of solar activity, which was found to be on the average close to spherically symmetric. The data show that on a spherically symmetric background an east–west asymmetry is observed, which indicates the presence of a large-scale structure of a spiral type in the solar wind. 相似文献
44.
We determine the behavior of onboard gas-generator flowrate for generating the cavitation flow around a hybrid aerial underwater vehicle by using an annular wing on the underwater trajectory section. 相似文献
45.
K. S. Kuz’mina I. K. Marchevskii V. S. Moreva E. P. Ryatina 《Russian Aeronautics (Iz VUZ)》2017,60(3):398-405
A high-accuracy numerical scheme is proposed for vortex methods of flow simulation around airfoils of arbitrary shape including airfoils with sharp edges, because it does not require the solution continuity on the airfoil. 相似文献
46.
This paper considers issues of designing a gas-turbine engine in the helicopter system at the early design stages. The optimum and rational values of engine working process parameters at different flight speeds of the flight vehicle (FV) are analyzed. Several characteristics of mathematical models (MM) that form the helicopter–engine system, are described. 相似文献
47.
B. A. Antuf’ev 《Russian Aeronautics (Iz VUZ)》2016,59(3):303-307
This study proposes an approximate solution to a contact problem of dynamic deformation of a cyclically symmetrical discretely ring-stiffened cylindrical shell, the side surface of which is subjected to an evenly distributed inertia live load. The solution of the problem assumes the quasistatic mode of deformation of the structure. Several critical velocities of the live load have been found. A number of examples are presented. 相似文献
48.
D. V. Nedel’ko 《Russian Aeronautics (Iz VUZ)》2016,59(3):297-302
A method of determining the maximum permissible values for diagnostic signs, being an integral part of health and usage monitoring systems (HUMS) of the helicopter transmission units, has been developed based on a probabilistic approach. 相似文献
49.
50.
This paper presents the results of analyzing the shaping of thin-walled conical parts with the uniform thickness along generatrix. 相似文献