GPS软件接收机中载波相位测量的实现

GPS接收机载波相位测量的精度优于码相位测量,但却存在整周模糊度。利用码和载波相位测量的组合可以提高伪距的精度,进而改善接收机的定位性能。研究GPS软件接收机中载波相位测量的实现方法。通过处理实际采集的信号,分析码和载波相位测量组合方法的性能。实验结果表明,通过50 s的平滑,伪距误差可以减小到毫米量级。     

虚拟仪器一仪器的新概念

从仪器的结构和性能特点方面，对虚拟仪器和传统仪器作了较详尽的比较，提出了“软件就是仪器”的新概念。为进一步阐明虚拟仪器的基本概念，列举并分析了ＶＸＩ总线虚拟仪器的软件框架。     

LTPB多站点联网测试软件设计

作为现役飞机最为先进航电技术的代表，高速数据总线在设计上的复杂性是显而易见的。如何对其性能进行全面考察是一个非常重要的问题。本文所论述的联网测试软件提供了一个有效的方法，实现了对LTPB联网性能的测试与演示。一方面证明了软件本身设计的合理笥，同时也进一步证明了整个LTPB设计与实施的正确性。     

建筑产品价格问题商榷

建筑产品价格如何确定，是造价管理体制改革中的热点问题，笔者对目前存在的三种意见进行分析后提出，应按照国际惯例，由建筑安装企业自行编制建筑安装产品的价格，参与市场竞争。     

SYNTHETIC STRESS LIFE TESTING OF MECHATRONIC PRODUCTS UNDER VARIABLE STRESS SPECTRUM

Mechatronic products usually endure the variable stress spectrum when they operate in certain operational condition and environmental condition, which obey the Weibull distribution. In accordance with the features of mechatronic product, this paper analyzes the failure mode, its corresponding sensitive stress and the design principles of life testing profiles. Based on the above analyses, this paper presents a synthetic stress life testing method based on the hybrid Weibull distribution and its statistical method under variable stress spectrum to evaluate the reliability and life indices of mechatronic products. Because the mechatronic products have many characteristics such as high price, long life and small testing samples, the synthetic stress life testing method under variable load spectrum can simulate the real various spectra, decrease the life testing time and reduce the testing samples. So it is effective to carry out the life testing to mechatronic products. The application results of hydraulic pumps indicate that this method can easily handle the experimental data under variable amplitude spectrum, obtain the high precision parameters point estimation and confidence interval estimation and reduce the testing cost greatly.     

SMT器件的生产和管理浅探

从我国当前的制造业形势、背景及航空微电子制造技术的发展特点出发,结合我所新产品开发和制造流程分析了当前的生产管理状况,对航空业进一步发展表面组装技术及其流水线规划和生产管理流程再造提出了建设性的方法和途径。     

Spatial and temporal monitoring of drought conditions using the satellite rainfall estimates and remote sensing optical and thermal measurements

Drought is an important natural disaster that causes devastating impacts on the ecosystem, livestock, environment, and society. So far, various remote-sensing methods have been developed to estimate drought conditions, each of which has advantages and restrictions. This study aims to monitor the real-time drought indices at the field scales via the integration of various earth observations. Our proposed method consists of two steps. In the first step, the relationships between long-term standardized precipitation indices (SPI) derived from PERSIANN-CDR rainfall data and two drought-dependent parameters derived from MODIS products, including normalized NDVI and soil-air temperature gradient, are obtained at the spatial resolution of PERSIANN-CDR grid (approximately 25 km). As the next step, the corresponding relationships are applied to estimate the drought index maps at the spatial resolution of MODIS products (1 km). Numerous analyses are carried out to evaluate the proposed method. The results revealed that, from various drought indices, including SPIs of different timescales (1, 3, 6, and 12-months), SPI-3 and SPI-6 are more appropriate to the proposed method in terms of correlation with temperature and vegetation parameters. The findings also demonstrate the competency of the proposed method in estimating SPI indices with average RMSE 0.67 and the average correlation coefficient of 0.74.     

军贸产品质量管理的思考

通过对军贸产品质量工作的分析,阐述了军贸产品质量管控的现状、存在的问题,提出了推进产品型谱和成熟度管理、加强计量保证工作、做实产品实现策划、强化产品供应链管理、开展综合保障工程等方面的工作建议,供参考。     

基于仿真优化的某航天产品装配线规划方法研究

航天产品的装配工艺复杂,具有典型的小批量、多品种特点,因此动态设置装配工位成为装配线规划的重要内容.本文以装配线平滑指数最小化为目标,以装配工艺、空间布局、路径等为约束条件,建立装配线工位数量优化模型.本文先对装配现场的不确定影响因素进行分析与建模,并提出基于仿真的优化方法,利用仿真模型模拟装配线运行状态,并通过遗传算法确定最优的工位数量,实现装配线的动态平衡,从而有效地提高装配线单元工位规划的精确度与效率.     

基于CMMI的配置管理系统设计与实现

在研究软件配置管理方法的基础上,结合CMMI配置管理要求以及航天测控软件配置管理实际需求,建立配置管理实施框架,实现了一个一体化的配置管理系统。该系统能够辅助开发人员和配置管理人员便捷地制定配置管理计划,进行配置标识、建立和发布基线、跟踪和控制更改、执行配置审核和报告的自动生成,实现了CMMI对软件配置管理的要求,提高了配置管理的自动化管理水平和易用性。