基于模糊机会约束规划的机会阵雷达方向图综合

针对机会阵雷达方向图综合的不确定问题,提出了一种基于模糊机会约束规划的方向图综合规划模型。该模型基于可信性理论,综合考虑天线单元分布的随机性以及激励状态的不确定性,将参与方向图综合时激励打开的天线数目看做一个梯形模糊变量,用以描述综合时的复杂不确定环境。随后,将规划模型转化为清晰等价形式,再结合遗传算法和灰关联综合评价法则设计了一种混合智能优化算法,用于求解该模型。以一维任意非均匀线阵为例,对主瓣宽度和最大副瓣电平进行了优化。仿真表明:优化后结果的可信性高于置信水平,验证了该算法的有效性。     

基于试验与蒙特卡洛法的子母弹子弹落点计算模型

针对目前子母弹子弹落点散布计算模型存在不足,影响子母弹毁伤效能评估准确性的问题,提出一种基于试验数据的子弹落点散布计算模型。对子母弹靶场试验数据进行分析处理,根据相邻子弹间距、不同环带中子弹数量的规律,建立了子弹落点散布模型;结合母弹散布,建立了子母弹子弹落点散布计算模型。该模型在给定子母弹散布参数后,可以快速生成群射子母弹子弹群的地面散布,且与实际情况基本相符,为子母弹毁伤效能评估奠定了基础。     

基于主动失谐优化的叶轮瞬态加减速振动抑制

提出了一种基于主动失谐优化的叶轮瞬态加减速振动抑制方法.首先建立了瞬态加减速激励下的叶轮降阶模型,获得了表征失谐对瞬态振幅影响的失谐放大因子.然后基于降阶模型,采用蒙特卡洛仿真快速计算了一系列瞬态激励下失谐放大因子的概率密度分布,结果表明:失谐放大因子在大多数瞬态激励下受到随机小失谐的影响大于在稳态激励下受到的影响,且...     

Surface Composition of Vesta: Issues and Integrated Approach

The instruments on the Dawn spacecraft are exceptionally well suited to characterize and map the surface composition of Vesta in an integrated manner. These include a framing camera with multispectral capabilities, a high spectral resolution near-infrared imaging spectrometer, and a gamma-ray and neutron spectrometer. Three examples of issues addressed at Vesta are: (1) What is the composition of Vesta??s interior and differentiation state as exposed by the Great South Crater? (2) How has space weathering affected Vesta, both globally and at a local scale? and (3) Are volatiles or hydrated material present on Vesta??s surface? We predict that Dawn finds many surprises, such as an olivine-bearing mantle exposed near the south-pole, a weakly or un-weathered surface that has been relatively recently resurfaced, and a very thin layer of surficial volatiles derived from interaction with the solar wind.     

Stochastic modelling considering ionospheric scintillation effects on GNSS relative and point positioning

Global Navigation Satellite Systems (GNSS), in particular the Global Positioning System (GPS), have been widely used for high accuracy geodetic positioning. The Least Squares functional models related to the GNSS observables have been more extensively studied than the corresponding stochastic models, given that the development of the latter is significantly more complex. As a result, a simplified stochastic model is often used in GNSS positioning, which assumes that all the GNSS observables are statistically independent and of the same quality, i.e. a similar variance is assigned indiscriminately to all of the measurements. However, the definition of the stochastic model may be approached from a more detailed perspective, considering specific effects affecting each observable individually, as for example the effects of ionospheric scintillation. These effects relate to phase and amplitude fluctuations in the satellites signals that occur due to diffraction on electron density irregularities in the ionosphere and are particularly relevant at equatorial and high latitude regions, especially during periods of high solar activity. As a consequence, degraded measurement quality and poorer positioning accuracy may result.     

卫星控制中心系统平台的高可用设计与实现

卫星控制中心是卫星地面测控管理系统的重要组成部分。随着信息技术的飞速发展和测控关键业务量的增长,高可用性、高可靠性及易维护日益成为卫星控制中心系统的设计目标。为满足卫星测控任务的需求,本文描述了卫星控制中心的网络系统、数据处理系统和数据库集群系统的高可用设计,并给出具体项目的成功实现。     

Study of the radiation environment on MIR space station with SILEYE-2 experiment.

In this work we present preliminary results of nuclear composition measurements on board space station MIR obtained with SILEYE-2 particle telescope. SILEYE-2 was placed on MIR in 1997 and has been working since then. It consists of an array of 6 active silicon strip detectors which allow nuclear and energetic identification of cosmic rays in the energy range between approximately 30 and 200 MeV/n. The device is attached to an helmet and connected to an eye mask which shields the cosmonaut eyes from light and allow studies of the Light Flashes (LF) phenomenon. In addition to the study of the causes of LF, the device is used to perform real time long term radiation environment monitoring inside the MIR, performing measurements in solar quiet and active days.     

分户供暖热计量系统的设计与实现

随着我国供热体制的改革,集中供暖分户计量工作已逐步得到推广.就目前各试点的运行情况来看,无论足热计量原理、温控方式、设备管理方式、还是在热费的计算上,都存在着很大的缺陷,导致了大量的热量浪费与热费争端.为此设计并实现了一种基于单片机的分户热计量系统.介绍了分户热计量的计量方案、设计思想、控制装置的组成结构和工作原理.该系统具有分户控温、分户计量、射频卡收费、GPRS远程报警、GSM短信设定等功能,比传统的集中供暖方式节能20%以上,具有很好的市场前景.     

Detrend effect on the scalograms of GPS power scintillation

The study of amplitude scintillation on GPS radio links is usually done after detrending the time series of the transmitted power so to define scintillations as the chaotic fluctuation around a unitary value. In a sense, the choice of how to detrend the time series is part of the definition of scintillation.     

建立虚拟现实空间的好助手-VRML

介绍了虚拟现实技术及VRML虚拟现实建模语言的概念,提出了用VRML虚拟现实建模语言设计软件时应该注意的一些问题,说明了用VRML虚拟现实建模语言设计的软件适用的范围,探讨了解决虚拟现实技术中存在问题的方法.