小波分析在外测数据滤波中的应用研究

为提高弹道估计精度,提出了一种基于小波分析的滤波方法,滤除外测数据中AR（自回归）模型的随机误差。分析讨论了滤波过程中的几个关键问题,提出了利用基于偏自相关系数截尾检验的方法来确定分解层数,然后采用GCV（广义交叉确认）准则来确定均方差意义下最优阈值的方法。本文提出的外测数据滤波方法计算简单,不需要估计噪声的方差。仿真结果表明,该方法能有效滤除外测数据中的AR噪声。     

氢化锂含氚量变化之数学模型的测定

氢化锂含氚量的实际及化与氚的自然衰变规律并不完全一致,为了测定其变化规律,对贮存中的氢化锂含氚量进行了长时间跟踪测量。本文利用实测数据与多项式回归法,结合氚的衰变规律建立了氢化锂含氚量变化的数学模型,此模型在测量点具有很低的预测误差。     

Influence of land surface parameters on the spatio-seasonal land surface temperature regime in rural West Bengal,India

The magnitude and causes of changes in the land surface temperature of rural areas have not been extensively studied. The thermal band of Landsat imagery is taken to extract winter, summer, and monsoon season land surface temperature (LST) and relate it to surface parameters over a 30-year period. From the extracted parameters constructed a prospective surface temperature (PST) model using Multivariate Adaptive Regression Splines. The Chandrabhaga river basin in West Bengal of the lateritic Rarh Tract at the Chota Nagpur Plateau fringe was chosen as the study area because it is far from urban influences, to avoid the well-known heat island effect. Over the study period, summer and winter average LST increased linearly by 0.085?°C/y and 0.016?°C/y respectively. These results were validated with air temperature (RMSE?=?x and y, respectively). Over time more of the area is in the higher temperature zones, e.g., in April 2011, 4% area exceeded >32°, whereas in 2015 this proportion reached 52%. PST models of all the seasons were moderate to highly correlate (0.57–0.87) with actual LST, showing the value of this model. It also revealed the relative importance of the regional factors. Based on this information factor management is a scientific step to restrict or minimize the temperature rise effect.     

Rapid deployment and continuous shape maintenance of tethered-space net robot based on single-pulse action

The tethered-space net robot is one of new technologies for capturing space debris. Rapid deployment and continuous shape maintenance of the tethered-space net robot system are essential in capturing space debris. A single-pulse rotation deployment strategy of the tethered-net robot system is proposed in this paper. The rapid deployment and continuous shape maintenance of the tethered-net are investigated through dimensional analysis, numerical simulation, and regression analysis. Results reveal that the single-pulse rotation deployment strategy can fully deploy the net and maintain the net-shape without any closed-loop controller, and it dramatically increases the effective deployment distance of the net. The parameter sensitivity analyses provide a reference for the rapid deployment and continuous shape maintenance of the tethered-space net robot system.     

线性回归模型的紧致最小二乘估计及参数分离

本文提出一种克服线性回归模型系数矩阵病态的“紧致最小二乘估计”。在此基础上,用部分验前知识,进一步对该有偏估计作了参数分离,从而得到全部待估参数的无偏估计。干涉仪雷达系统性误差的模拟计算表明:效果良好,优于主成分估计。本文在理论及应用上(特别对飞行试验的外测及制导系统精度分析),具有重要意义。     

小卫星的成本估算

介绍了建立卫星成本估算关系式所用的回归分析法;重点给出了以近年来２９颗国外小卫星的实际成本数据为依据,用回归分析法拟合,得出小卫星的成本估算关系式;除了给出最常见的以卫星干质量为自变量的成本估算关系式外,还给出了以其他功能、性能参数为自变量的、多种形式的成本估算关系式;并以实例,对不同的自变量计算出成本估算值,取他们的带权平均值得到最后的小卫星成本估算值;最后给出了含双自变量的小卫星成本估算关系式。     

热应力检测中的温升计算

为了消除样本周期对实时计算的局限,采用了样本区间步进的方式,确保样本间隔最短（一个采样本间）。新样本将包含前一样本的部分数据,并采用线性回归平滑数据克服非线性影响,提高数据滤波效果。计算温升率的回归递推公式提高了数据平滑和温升率计算的实时性。数值模拟结果表明该递推公式具有良好的滤波效果和收敛性。     

聚乙烯在固体燃料冲压发动机中燃烧特性的数值研究

为准确模拟聚乙烯在固体燃料冲压发动机中的燃烧状态,估算了乙烯-空气两步反应中,相关组分的粘性、导热系数随温度的变化,并进行多项式拟合;同时使用UDF进行质量、动量、能量添加.数值计算的结果表明:燃面退移速率的计算误差不超过11.3％,其变化规律与已有实验相同;补燃室温度的误差不大于5.2％;补燃室温度随来流空气质量流率的增大而减小;高来流空气总温或低来流空气质量流率的工况下,燃料充分燃烧所需的补燃室更长;几何相似,其它条件相同时,小尺寸发动机内流场传向燃料表面的热流密度更大,燃面退移速率更高.     

Integrating Non-Tidal Sea Level data from altimetry and tide gauges for coastal sea level prediction

The main objective of this paper is to integrate Non-Tidal Sea Level (NSL) from the joint TOPEX, Jason-1 and Jason-2 satellite altimetry with tide gauge data at the west and north coast of the United Kingdom for coastal sea level prediction. The temporal correlation coefficient between altimetric NSLs and tide gauge data reaches a maximum higher than 90% for each gauge. The results show that the multivariate regression approach can efficiently integrate the two types of data in the coastal waters of the area. The Multivariate Regression Model is established by integrating the along-track NSL from the joint TOPEX/Jason-1/Jason-2 altimeters with that from eleven tide gauges. The model results give a maximum hindcast skill of 0.95, which means maximum 95% of NSL variance can be explained by the model. The minimum Root Mean Square Error (RMSe) between altimetric observations and model predictions is 4.99 cm in the area. The validation of the model using Envisat satellite altimetric data gives a maximum temporal correlation coefficient of 0.96 and a minimum RMSe of 4.39 cm between altimetric observations and model predictions, respectively. The model is furthermore used to predict high frequency NSL variation (i.e., every 15 min) during a storm surge event at an independent tide gauge station at the Northeast of the UK (Aberdeen).     

我国航空客运市场需求与经济关联性分析

本文探讨航空客运市场需求与经济的关联性,以此反映我国航空客运需求的主要特点;主要从三个方面通过SPSS回归分析来阐述我国航空客运运输市场需求与经济之间的关联性,并利用回归模型对未来航空客运市场需求进行了预测。