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1.
以无动力航空自导深弹为研究对象,在分析反潜直升机攻潜过程的基础上,建立起反潜直升机应召攻潜航路规划模型,进而建立反潜直升机投放深弹模型,并利用Simulink对航空深弹空中弹道进行仿真,得出航空深弹入水的相关参数,为航空深弹作战使用提供理论参考。  相似文献   

2.
主要介绍了神经网络系统、遗传算法、粒子群算法、模拟退火算法、支持向量机几种启发式优化算法(Heuristic Optimization Algorithm,HOA)在大飞机设计领域的发展和应用现状,对比分析了算法在航空工程设计上的优缺点,展望了启发式算法的发展方向,为大飞机设计提供了宝贵的理论和经验。  相似文献   

3.
高等职业教育在现代职业教育体系建设进程中具有引领作用,《教育纲要》给职业教育提出新课题,国家产业发展趋势给职业教育提出新思考,向中国创造转变给职业教育提出新期望。以西安航空职业技术学院为例分析高职教育改革的现状和发展方向。高职院校必须根据自身所处的区域社会经济环境来制定学校发展战略,明确定位,办出特色,这对高职高专院校的发展具有一定的借鉴和现实意义。  相似文献   

4.
Cosmic ray particles respond to the heliospheric magnetic field in the expanding solar wind and its turbulence and therefore provide a unique probe for conditions in the changing heliosphere. During the last four years, concentrated around the solar minimum period of solar cycle 22, the exploration of the solar polar regions by the joint ESA/NASA mission Ulysses revealed the three-dimensional behavior of cosmic rays in the inner and middle heliosphere. Also during the last decades, the Pioneer and Voyager missions have greatly expanded our understanding of the structure and extent of the outer heliosphere. Simultaneously, numerical models describing the propagation of galactic cosmic rays are becoming sophisticated tools for interpreting and understanding these observations. We give an introduction to the subject of the modulation of galactic cosmic rays in the heliosphere during solar minimum. The modulation effects on cosmic rays of corotating interaction regions and their successors in the outer heliosphere are discussed in more detail by Gazis, McDonald et al. (1999) and McKibben, Jokipii et al. (1999) in this volume. Cosmic-ray observations from the Ulysses spacecraft at high heliographic latitudes are also described extensively in this volume by Kunow, Lee et al. (1999). This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

5.
越来越复杂的产品工程与越来越要求产品个性化的消费者需求对传统的大规模生产方式提出挑战。而模块化的生产方式兼顾产品的通用性和灵活性,能够在大规模生产的同时实现产品品种的多样性,从而成为解决消费者需求定制与大规模批量生产二者之间矛盾的重要手段。通过对现有文献的分析,总结出推动模块化生产方式形成发展的动因主要是技术的不断发展和分工的不断深化、适应消费者需求的多样化与个性化以及实现各个经济主体的收益增加。另外,模块化生产对企业在全球竞争中取得成功起着至关重要的作用,它能够提高企业柔性,促进新产品研发绩效以及提升顾客满意度,从而为企业赢得竞争优势。  相似文献   

6.
The probability hypothesis density (PHD) filter is a practical alternative to the optimal Bayesian multi-target Alter based on finite set statistics. It propagates the PHD function, a first-order moment of the full multi-target posterior density. The peaks of the PHD function give estimates of target states. However, the PHD filter keeps no record of target identities and hence does not produce track-valued estimates of individual targets. We propose two different schemes according to which PHD filter can provide track-valued estimates of individual targets. Both schemes use the probabilistic data-association functionality albeit in different ways. In the first scheme, the outputs of the PHD filter are partitioned into tracks by performing track-to-estimate association. The second scheme uses the PHD filter as a clutter filter to eliminate some of the clutter from the measurement set before it is subjected to existing data association techniques. In both schemes, the PHD filter effectively reduces the size of the data that would be subject to data association. We consider the use of multiple hypothesis tracking (MHT) for the purpose of data association. The performance of the proposed schemes are discussed and compared with that of MHT.  相似文献   

7.
In this article, I will attempt to give an overview of the motivations for studying black holes and of the current major problems in the field. I will also give some perspectives on what can be done in the future, focusing on instrumentation which has already been approved. This chapter will necessarily be more speculative than the other chapters in this volume.  相似文献   

8.
Conclusions Experimental studies of the radiation zones have been subject to the same imperfections as most other experimental physics, with some extra problems because of the features peculiar to rocket and satellite work. We consider that the theoretical physicists must review the existing knowledge, and suggest specific experiments which would be of particular significance. The theoretical studies of radiation-zone phenomena are so new that the theoretician can start essentially afresh, without being fettered by theories based more on longevity than veracity. We trust that this critical review of experimental work may be of value in such efforts.The following quotation from Maritain(1959) is so apt to this paper that it will serve as a conclusion:The intellect ... is no longer interested in anything but the invention of apparatus to capture phenomena — conceptual nets that give the mind a certain practical dominion over nature, coupled with a deceptive understanding of it; ... by advancing in this fashion, not by linking new truths to already acquired truths, but by substituting new apparatus for outmoded apparatus; by handling things without under standing them; by gaining ground against the real bit by bit, patiently, through victories that are always piecemeal and provisory — by acquiring a secret taste for the matter with which it conspires — thus has the modern intellect developed within this lower order of demiurgy a kind of manifold and marvellously specialized touch as well as wonderful instincts for the chase.  相似文献   

9.
This collection of reviews marks the state of the art of geomagnetic data collection, modelling, and interpretation at a time of unprecedented advances in all 3 facets of the subject. For the first time we have excellent satellite data with the prospect of more to come, vast improvements in laboratory techniques, and opportunities to use large scale computing to model the data. In the past, research has been conducted by the separate disciplines largely in isolation; we can hope the subject has now matured enough for progress to be made by genuine collaboration between theoreticians and experimentalists. The purpose of this chapter is to set the historical setting, and I have chosen a starting date of 1980, when vector satellite data first became available and stimulated many new advances in the subject. We can hope for a similar or better stimulus in the next decade.  相似文献   

10.
在法学本科教育开创伊始,对其一系列问题急需进行全面的、系统的研讨,从而推动中国民航学院法学本科教育的发展和繁荣。对法学本科教育的教育目的进行了研究。  相似文献   

11.
In the present work we intend to show that a stellar dynamo mechanism can produce high X-ray luminosities and also give account for modulation periods of the order thousand seconds or larger.We outline here that the model we propose does not require the presence of a very compact object in a binary system; indeed, we intend to show that faint late main sequence stars sufficiently fast rotating, can give rise by dynamo action to sufficiently high magnetic fields to give account for the strong X-ray emission of some galactic X-ray sources.We examine the possibility that also a fraction of those X-ray sources usually depicted as accreting binary systems may be interpreted as active stars supplied by the - dynamo mechanism.  相似文献   

12.
We present a new method for a high-accuracy reconstruction of the attitude for a slowly spinning satellite. This method, referred to as the fully-dynamic approach, explores the possibility to describe the satellite's attitude as that of a rigid body subject to continuous external torques. The method is tried out on the Hipparcos data and is shown to reduce the noise for the along-scan attitude reconstruction for that mission by about a factor two to three. The dynamic modelling is expected to give a more accurate representation of the satellite's attitude than was obtained with a pure mathematical modelling. As such, it decreases the degrees of freedom in the a posteriori reconstruction. Some of the decrease is obtained through accumulating and subsequently implementing information on high frequency components in the solar radiation torques, which show to be systematic and predictable. This could be expected, as they are primarily linked to the external geometry and optical properties of the satellite. In the context of an astrometric mission, the methods presented here can only be applied as a final iteration step: the star positions that are used to reconstruct the attitude are also part of the scientific objectives of the mission. An estimate for the potential of a re-reduction of the Hipparcos data using the fully-dynamic model for the attitude reconstruction was obtained from test reductions of the first 24 months of mission data. Improvement of the accuracies of the astrometric parameters for all stars brighter than Hp=9.0 appears possible. The noise on the astrometric parameters for these stars was affected significantly by the along-scan attitude noise, which dominated for stars brighter than Hp=4.5. The possible improvement for stars brighter than about Hp=4.5 may, after iterations, be as much as a factor three. The reduced noise levels also allow a more accurate calibration and monitoring of instrument parameters, leading potentially to a better understanding of the instrument and the scientific data obtained with it. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

13.
高校图书馆特色馆藏建设有六个基本原则,首先应与学校学科特色发展相符合,其次应遵循与原有馆藏资源的连贯性和均衡性,与学校发展和读者的需求相协调,各种载体文献最优化组配,合理使用经费,走资源共享的道路和自建具有本校特色的数据库。  相似文献   

14.
介绍了以凌阳单片机SPCE061A板为核心作为悬挂运动控制的系统,实现了键盘输入识别、传感器信号采集、电机驱动电路控制等功能。根据物体在平面任一处两端吊绳的长度唯一确定的原理,通过单片机编程控制电机转动带动吊绳伸长或缩短,实现物体沿任意设定轨迹运动。引导部分用反射式红外传感器探测板面黑线,信息送入单片机处理后,控制物块沿黑线前进。该系统可以完成到达任意预设坐标,沿自行设定轨迹运动,以板上任意处为圆心画直径为50cm的圆和寻黑线前进任务。  相似文献   

15.
We present the work of an international team at the International Space Science Institute (ISSI) in Bern that worked together to review the current observational and theoretical status of the non-virialised X-ray emission components in clusters of galaxies. The subject is important for the study of large-scale hierarchical structure formation and to shed light on the “missing baryon” problem. The topics of the team work include thermal emission and absorption from the warm-hot intergalactic medium, non-thermal X-ray emission in clusters of galaxies, physical processes and chemical enrichment of this medium and clusters of galaxies, and the relationship between all these processes. One of the main goals of the team is to write and discuss a series of review papers on this subject. These reviews are intended as introductory text and reference for scientists wishing to work actively in this field. The team consists of sixteen experts in observations, theory and numerical simulations.  相似文献   

16.
Introduction     
This Introduction attempts to place the 2005 ISSI Workshop on “Solar Variability and Planetary Climates” in the context of the recent history of the subject and to identify key areas where progress has been, and is being, made in understanding the many complex issues involved.  相似文献   

17.
We discuss the importance of the spectral range from about 80 to 800 Å for determining physical conditions in different regions of the solar atmosphere. We give examples of line ratios that may be used to determine electron densities in quiet Sun regions, active regions, and flares. We discuss the possibility of determining electron temperatures from line ratios in the EUV.We show that profiles as well as intensities of spectral lines must be obtained for a proper interpretation of the spectra. We give approximate parameters for a solar grazing incidence spectrograph suitable for the study of the 80–800 Å wavelength region.Given as an invited review paper at the EGAS Meeting in Munich, Germany, 11–14 July 1978.  相似文献   

18.
Certain fundamental scientific problems of a cosmological as well as cosmogonic character, may be solved by the insertion of entry probes into the atmospheres of the outer planets. It is recommended that attempts be made to determine the elemental and isotopic abundances of H, D, He3, He4, C, N, O, S, and the rare gas elements. These determinations should cast much light on the processes which participated in the assembly of the giant planets. This would give powerful boundary conditions on theories of the origin of the solar system, and would also give additional experimental information bearing on cosmology.This is one of the publications by the Science Advisory Group.  相似文献   

19.
This paper discusses the subject of applying artificial Intelligence (AI) techniques to automatic test. It has been the experience of the author that AI is not a “magic bullet”, and that its successful use requires an understanding of both the technology and the repair process to which it is being applied  相似文献   

20.
危机管理的多重研究向度   总被引:1,自引:0,他引:1  
研究危机管理,既要运用管理学的基本原理,又要借助多学科的思想方法。考虑到管理学的形成历史、美国杰出CEO的人格特征、企业的内外环境等因素,管理学、传记文学、军事学、心理学是值得关注的研究向度。相关学科的滋养和支撑,为危机管理提供了新的审视角度和研究策略,昭示出认知、反思、预测诸功能,契合人性、贴近理论、反哺实践,呈现独特的学术价值和应用价值。  相似文献   

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