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211.
Siyu Tang Zhi Huang Hong Yuan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(2):722-730
Radial basis function (RBF) interpolation with multi-quadric is developed to perform ionospheric total electron content (TEC) mapping for the Chinese region between 15°N ~ 40°N and 100°E ~ 125°E. TEC measurements from the Centre for Orbit Determination in Europe (CODE) covering the solar maximum year 2011 are used to investigate the performance of the proposed RBF interpolation method. The differences between the RBF interpolated TEC and the CODE TEC are within 0.5 TECU and the root mean square error (RMSE) is very small when 49 data points are used. The maximum difference is ~5 TECU and the error is less than 1 TECU with 25 samples. Our study suggests that a random distribution of measurement points gives smaller RMSEs than a homogenous distribution when the number of sample points is low. The study indicates that RBF interpolation offers a powerful and reliable tool for ionospheric TEC mapping. 相似文献
212.
Abstract The present work explores an interactive model of spatial and temporal information in map memory. In four experiments, participants learned a map with temporal and spatial information confounded or unconfounded. Attentional and representational levels of information were made apparent through tasks that tap spatial, temporal, or other information. Learning criteria emphasizing sequential order or location imposed differential weighting of the information types in memory. Results indicate that map memory is spatial, but also interacts with the order in which map locations are encountered. Findings show flexibility in allocating attention and information indexing of location and sequential order information in map learning. 相似文献
213.
江慎铭 《南昌航空工业学院学报》2009,23(1):17-21
本文主要在FC-空间内讨论一类截口定理,得到一些存在性定理,这些结果推广和改进了最近一些成果. 相似文献
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215.
Mineral mapping in the Kap Simpson complex,central East Greenland,using HyMap and ASTER remote sensing data 总被引:1,自引:0,他引:1
Enton Bedini 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
This research focuses on the application of HyMap airborne hyperspectral data and ASTER satellite multispectral data to mineral exploration and lithologic mapping in the Arctic regions of central East Greenland. The study area is the Kap Simpson complex in central East Greenland. The Kap Simpson complex is one of the largest exposed Palaeogene felsic complexes of East Greenland. It has been the target of several mineral exploration projects. The analysis of the HyMap data produced a detailed picture of the spatial distribution of the alteration minerals in the Kap Simpson complex, unavailable from field-based studies in the area. The analysis of the ASTER data produced mineral maps which due to the moderate spatial and spectral resolution of the ASTER imagery can be useful for reconnaissance level mineral exploration. Colour composites of the mean normalized ASTER thermal bands display lithological information and detected a large felsic igneous intrusion that has not been shown on the recently compiled geological maps of the area. The results of this research have considerable potential to evaluate the use of hyperspectral and multispectral remote sensing for geological purposes in the Arctic regions of central East Greenland. 相似文献
216.
Nicholas A. Giudice Roberta L. Klatzky Jack M. Loomis 《Spatial Cognition & Computation》2013,13(4):287-304
Abstract Participants learned circular layouts of six objects presented haptically or visually, then indicated the direction from a start target to an end target of the same or different modality (intramodal versus intermodal). When objects from the two modalities were learned separately, superior performance for intramodal trials indicated a cost of switching between modalities. When a bimodal layout intermixing modalities was learned, intra- and intermodal trials did not differ reliably. These findings indicate that a spatial image, independent of input modality, can be formed when inputs are spatially and temporally congruent, but not when modalities are temporally segregated in learning. 相似文献
217.
本文将Fuuzy压缩原理进行了推广,首次通过引入一个Fuzzy ε上半连续函数和Fuzzy链空间成功的证明了Fuzzy数值函数的不动点定理。 相似文献
218.
为提升机械臂系统对环境的感知能力,针对机械臂多工位精确对准问题,提出了一种具有远近视距引导的机械臂多工位对准技术。首先构造具有远近视距的两目视觉配置,并与机械臂构成Eye-in-hand视觉反馈系统。然后标定两目视觉的内外参数和手眼关系变换矩阵。通过离线先验局部对准方式,建立各工位的任务表。提出了三阶段对准策略,即多工位作业起始位姿获取、全局相机的初定位和局域相机的精对准,使得机械臂能在多个工位下实现末端工具与目标的精确对准。通过多位置孔轴对准实验验证了本文方法的可行性。单个孔位重复对准标准差角度不超过0.015°,位置不超过0.078 mm,三阶段对准实验结果表明,角度误差小于0.05°,位置误差小于0.17 mm。 相似文献
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220.
以复杂背景下空中飞行器的鲁棒视觉跟踪问题为研究背景,为解决现有跟踪方法目标表征模型不够精确,算法鲁棒性严重受到目标形变、宽高比变化、复杂背景等因素干扰的问题,提出了建模跟踪场景中独立物体的显著性特性,用于构建精确的目标模型。提出的显著性估计方法有别于传统的单帧检测方法,利用跟踪算法提供的背景先验知识以及多帧图像观测数据,使用时空联合的方式进行建模估计,其结果用来指导目标跟踪算法选取有效视觉特征,建立精确目标表征模型,减小背景区域对算法模型的干扰。实验表明,提出的方法为上述难点问题提供了有效的解决方案,对空中飞行器的跟踪精度与鲁棒性优于大多数最先进的主流方法,在其他类型的目标跟踪任务中也有十分优越的性能表现。 相似文献