Longitudinal parameter identification of a small unmanned aerial vehicle based on modified particle swarm optimization

This paper describes a longitudinal parameter identification procedure for a small unmanned aerial vehicle(UAV)through modified particle swam optimization(PSO).The procedure is demonstrated using a small UAV equipped with only an micro-electro-mechanical systems(MEMS)inertial measuring element and a global positioning system(GPS)receiver to provide test information.A small UAV longitudinal parameter mathematical model is derived and the modified method is proposed based on PSO with selective particle regeneration(SRPSO).Once modified PSO is applied to the mathematical model,the simulation results show that the mathematical model is correct,and aerodynamic parameters and coefficients of the propeller can be identified accurately.Results are compared with those of PSO and SRPSO and the comparison shows that the proposed method is more robust and faster than the other methods for the longitudinal parameter identification of the small UAV.Some parameter identification results are affected slightly by noise,but the identification results are very good overall.Eventually,experimental validation is employed to test the proposed method,which demonstrates the usefulness of this method.     

大数据量采集系统设计的几个细节

本文主要介绍大数据量数据采集系统的设计细节。硬件选择方案,软件设计细节及大量数据的处理方法。     

技术创新的决策研究与新产品开发

对技术创新的主要研究领域——新产品开发方面进行了综合研究。所提出的多目标决策分析的两两目标对比法、新产品开发层次分析模型、以及专家系统新产品开发模型可分别应用于不同复杂度的新产品开发环境。文中讨论了这三种新产品开发模型的内在联系。     

飞机全生命期过程建模方法与技术

论述了飞机全生命期过程建模的必要性,介绍了针对飞机这样的大型复杂过程的建模技术,已 开发的产品过程建模和模拟软件工具,以及该工具用于某型号飞机研制过程的建模情况。     

对当前过程建模方法的分类评注

对当前存在的各种软件过程建模方法作了详细讨论，提出了几种分类，并对各种建模方法做了评注，最后对过程建模的发展趋势提出了自己的看法。     

碳纤维预浸渍中树脂含量的研究

介绍了碳纤维预浸渍成型中树脂含量对单向强力环、φ１５０ｍｍ壳体性能的影响，并对影响树脂含量的主要因素进行了较为全面的分析，确定了树脂含量的参数范围，试验结果表明该参数是合理的。     

新型热熔浸渍技术及其应用前景

介绍了一种新型热熔浸渍工艺及配方，专门用于生产供缠绕用的３～１５ｍｍ高性能碳纤维／环氧预浸带。它不用分离纸；胶液不预反应，不预制股膜，工艺和设备简单；生产成本低；浸清质量好，壳体性能高。在固体火箭发动机壳体制造中具有良好的应用前景。     

Radiation driven winds of hot stars: Theory of O-star atmospheres as a spectroscopic tool

The status of the continuing effort to construct radiation driven wind models for O-Stars atmospheres is reviewed. Emphasis is given to several problems relating to the fomation of UV line spectra the use of accurate atomic data, the inclusion of EUV radiation by shock heated matter, the simulation of photospheric line blocking.A new tool for O-star diagnostics is presented. This is based on the use of wind models to calculate synthetic high resolution spectra covering the observable UV region. A comparison with observed spectra then gives physical constraints on the properties of stellar winds and stellar parameters, additionally abundances can be determined.The astrophysical potential of this method is demonstrated by an application to two Of-stars, the galactic O4f-star -Puppis and the LMC O3f-star Melnick 42. With regard to effective temperatures and gravities, the results from the application of classical methods to the analysis of photospheric lines are only partially verified. Explanations for the shortcomings of classical NLTE methods are discussed.     

Spectral analyses of Wolf-Rayet stars: Theory,results, conclusions

Stratified Non-LTE models for expanding atmospheres became available in the recent years. They are based on the idealizing assumptions of spherical symmetry, stationarity and radiative equilibrium. From a critical discussion we conclude that this standard model is basically adequate for describing real Wolf-Rayet atmospheres and hence can be applied for quantitative spectral analyses of their spectra.By means of these models, the fundamental parameters have been determined meanwhile for the majority of the known Galactic WR stars. Most of them populate a vertical strip in the Herzsprung-Russell diagram at effective temperatures of 35 kK, the luminosities ranging from 10^4.5 to 10^5.9 L . Only early-type WN stars with strong lines and WC stars are hotter. The chemical composition of WR atmospheres corresponds to nuclear-processed material (WN: hydrogen burning in the CNO cycle; WC: helium burning). Hydrogen is depleted but still detectable in the cooler part of the WN subclass.Different scenarios for the evolutionary formation of the Wolf-Rayet stars are discussed in the light of the empirical data provided from the spectral analyses. Post-red-supergiant evolution can principally explain the basic observational properties, except the rather low luminosities of a considerable fraction of WN stars. Among the alternative scenarios, close-binary evolution can theoretically produce the least-luminous WN stars. However, final conclusions about the evolutionary formation of the WR stars are not yet possible.     

带有转轮的空间转轴起落架理论图设计原理

 <正> 1.前言 飞机采用空间转轴起落架一般有两种型式,其中之一为A型(图1(a)),支柱与机轮等构件相对位置保持不变,一起绕空间轴收入起落架舱;另一种为B型(图1(b)),它有两部分运动:一是支柱绕空间轴运动,一是机轮随支柱转动的同时,再相对支柱的转轮运动。