几何语言与建筑设计

通过几何学中的点、线、面同造型艺术中点、线、面的联系，论述了几何形体对人的视觉心理感觉和形成的语言在建筑设计中的作用及重要性。并从中体现出建筑语言在人心中的反映。     

Coupling Magneto-Electro-Elastic node-based smoothed radial point interpolation method for free vibration and transient analysis of Functionally Graded Magneto-Electro-Elastic structures

A Coupling Magneto-Electro-Elastic (MEE) Node-based Smoothed Radial Point Interpolation Method (CM-NS-RPIM) was proposed to solve the free vibration and transient responses of Functionally Graded Magneto-Electro-Elastic (FGMEE) structures. By introducing the modified Newmark method, the displacement, electrical potential and magnetic potential of the structures under transient mechanical loading were obtained. Based on G space theory and the weakened weak (W²) formulation, the equations of the multi-physics coupling problems were derived. Using triangular background elements, the free vibration and transient responses of three numerical examples were studied. Results proved that CM-NS-RPIM performed better than the standard FEM by reducing the overly-stiff of structures. Moreover, CM-NS-RPIM could reduce the number of nodes while guaranteeing the accuracy. Besides, triangular elements could be generated automatically even for complex geometries. Therefore, the effectiveness and validity of CM-NS-RPIM were demonstrated, which were valuable for the design of intelligence devices, such as energy harvesters and sensors.     

Adjustment of systematic errors in ALS data through surface matching

Surface matching is a well researched topic in both Computer Vision (CV) and terrestrial laser scanning (TLS) or ground based light detection and ranging (LiDAR), but the extent of the range images derived from these technologies is typically orders of magnitude smaller than those derived from airborne laser scanning (ALS), also known as airborne LiDAR. Iterative closest point (ICP) and its variants have been successfully used to align and register multiple overlapping views of the range images for CV and TLS applications. However, many challenges are encountered in applying the ICP approach to ALS data sets. In this paper, we address these issues, explore the possibility of automating the algorithm, and present a technique to adjust systematic discrepancies in overlapping strips, using geometrical attributes in a given terrain. In this method, the ALS point samples used in the algorithm are selected depending on their ability to constrain the relative movement between the overlapping laser strips. The points from overlapping strips are matched through modified point to plane based on the ICP method.     

广义均衡问题和不动点问题的收敛性定理及应用

运用平行算法，提出一种寻求广义均衡问题解及有限个严格伪压缩映像不动点集的公共元的新的迭代格式．在Hilbert空间中．证明了该算法的强收敛性。     

Hilbert空间上Lipschitz伪压缩映像族的强收敛定理

给出并证明了一个Lipschitz伪压缩映像族的强收敛算法,推广了Yao等人的结果。     

一种改进的模糊度子集选取方法及其性能评估

模糊度固定(ambiguity resolution, AR)能在一定程度上加快精密单点定位收敛并提高定位精度。但是模糊度固定率和计算效率会随模糊度数量的增加而降低,因此部分模糊度固定(partial ambiguity resolution, PAR)备受关注。PAR技术的关键在于模糊度子集选取,提出了一种改进的模糊度子集选取法,将高度角、信噪比以及模糊度方差联合作为模糊度子集选取的指标。实验结果表明：静态模式下,相比于全模糊度固定(full ambiguity resolution, FAR)和基于高度角的PAR方法,该方法的固定率分别提升9.65%和2.56%,首次固定时间分别缩短6.86%和3.43%,收敛时间分别缩短15.57%和5.13%,当三种方法固定率大致相同时,定位精度分别提升4.74%和5.39%;动态模式下,该方法的固定率分别提升22.75%和0.92%,首次固定时间分别缩短12.44%和0.44%,当三种方法固定率大致相同时,定位精度分别提升3.50%和4.89%。总体而言,无论是在静态还是动态模式下,该方法相比于FAR和基于高度角的PAR方法,性能均有所提升。     

基于原始观测值的UWB增强GNSS精密单点定位方法研究

全球卫星导航系统(global navigation satellite system, GNSS)可提供全球范围内全天候高精度导航、定位和授时服务。以精密单点定位(precise point positioning, PPP)为代表的绝对定位技术凭借定位精度高且全球一致、作业范围灵活等优势受到广泛关注,但是较长的收敛时间,限制了其在实时、快速精密定位应用中的使用。为解决上述问题,提出了超宽带(ultra-wideband, UWB)增强PPP方法,在多星座PPP中紧密集成UWB测距信息,以提高GNSS PPP性能。实验结果表明,在动态场景下,融合UWB量测使GPS/GAL双系统PPP在东、北、天3个方向的位置均方根(root mean square, RMS)值分别减少了76.99%、21.46%、64.53%,GPS/GAL/BDS三系统PPP减少了69.69%、37.21%、61.32%,并且收敛时间分别加快62.78%和57.75%。关于锚点数(几何构型)的评估表明,仅利用4个锚点就能将双系统和三系统3D误差RMS值减少67.98%、59.35%,收敛时间加快76.14%、62...     

基于改进YOLOv3网络的遥感目标快速检测方法

针对将来卫星在轨实时目标检测需求,且在其内存和算力都受限的条件下,提出一种改进的YOLOv3,利用轻量化网络代替YOLOv3的特征提取网络,实现遥感目标的高效检测。在目标检测精度相近的情况下,改进模型参数相比原先降低了1.5倍,计算量降低了3.3倍。同时提出了一种基于交并比的迭代聚类算法,分别在YOLOv3和改进YOLOv3上实现了7.0%和2.3%的平均精度均值(mAP)提升。实验表明:改进模型的检测速度最快能达到101 frame/s,当其mAP比YOLOv3高6%时,检测速度仍是YOLOv3的1.6倍。本文提出的改进YOLOv3是一种高效遥感目标检测方法,为未来星上应用打下基础。     

弹道式再入航天器落点预报技术

建立了航天器弹道式再入动力学模型,并针对航天器在着陆前开减速伞导致高空风对航天器落点影响大的特点,建立了高空风对航天器的动力学模型。提出了基于高空风实时修正的航天器落点预报算法。相比以往的算法,该算法无需提前计算高空风修正插值表。经实测数据验证,算法显著提高了航天器的落点预报精度。     

格尼襟翼在冰风洞混合翼设计中的应用

提出面向工程、面向适航的混合翼设计准则,基于此准则提出将格尼襟翼应用于民机机翼结冰风洞试验的单段混合翼设计中。设计准则中只对驻点位置和前缘吸力峰值提出保守性要求,易于工程实现,满足结冰适航要求。对于偏离设计点较大的状态,在单段混合翼后缘添加格尼襟翼并配合迎角调整,使得单段混合翼在此状态点处仍满足设计准则。这样使得单段混合翼也能应用于试验状态比较广的结冰风洞试验中。格尼襟翼的使用,降低了混合翼设计、试验费用,为民机结冰试航取证节约了时间。