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排序方式: 共有473条查询结果,搜索用时 15 毫秒
71.
K. Fujita T. Hanada Y. Kitazawa A. Kawabe 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
This study proposes a motion detection and object tracking technique for GEO debris in a sequence of images. A couple of techniques (called the “stacking method” and “line-identifying technique”) were recently proposed to address the same problem. Although these techniques are effective at detecting the debris position and motion in the image sequences, there are some issues concerned with computational load and assumed debris motion. This study derives a method to estimate motion vectors of objects in image sequence and finally detect the debris locations by using a computer vision technique called an optical flow algorithm. The new method detects these parameters in low computational time in a serial manner, which implies that it has an advantage to track not only linear but also nonlinear motion of GEO debris more easily than the previous methods. The feasibility of the proposed methods is validated using real and synthesized image sequences which contain some typical debris motions. 相似文献
72.
以星体表面的图像数据为基础,根据撞击坑的向阳面呈亮色调而背阳面呈暗色调的原理,提出了一种基于图像的星体表面撞击坑自动提取方法。该方法先用自适应双阈值分割法对星体表面的光学图像进行分割处理,获取图像中明暗区域的形状和位置信息;再用统计学原理分析明暗区域组成结构、像平面上光照方向,结合相关的约束条件来匹配同一撞击坑的明暗区域,同时拟合出撞击坑的外边缘并确定其半径、位置等信息。实验结果表明,该方法能够从常见的星体表面光学图像中快速、可靠地提取出撞击坑的中心位置和半径大小,具有较宽的普适应性和一定的应用价值。 相似文献
73.
针对WorldView-2卫星遥感图像,提出一种基于波段分组的多光谱图像与全色光图像融合新方法。该方法以全色光波段与多光谱各波段光谱响应的匹配特点为依据,首先将八波段多光谱图像分成两组,然后分别设计融合模型再进行分组融合,最终得到多光谱各波段的融合结果,分组策略简单、实用。实验结果表明,该方法在融合WorldView-2遥感图像时能够在提高空间分辨率和保持光谱信息方面达到更好的平衡,优于现有的几种融合方法。 相似文献
74.
《中国航空学报》2021,34(9):47-59
The aircraft system has recently gained its reputation as a reliable and efficient tool for sensing and parsing aerial scenes. However, accurate and fast semantic segmentation of high-resolution aerial images for remote sensing applications is still facing three challenges: the requirements for limited processing resources and low-latency operations based on aerial platforms, the balance between high accuracy and real-time efficiency for model performance, and the confusing objects with large intra-class variations and small inter-class differences in high-resolution aerial images. To address these issues, a lightweight and dual-path deep convolutional architecture, namely Aerial Bilateral Segmentation Network (Aerial-BiSeNet), is proposed to perform real-time segmentation on high-resolution aerial images with favorable accuracy. Specifically, inspired by the receptive field concept in human visual systems, Receptive Field Module (RFM) is proposed to encode rich multi-scale contextual information. Based on channel attention mechanism, two novel modules, called Feature Attention Module (FAM) and Channel Attention based Feature Fusion Module (CAFFM) respectively, are proposed to refine and combine features effectively to boost the model performance. Aerial-BiSeNet is evaluated on the Potsdam and Vaihingen datasets, where leading performance is reported compared with other state-of-the-art models, in terms of both accuracy and efficiency. 相似文献
75.
民用航空发动机单元体送修工作范围决策 总被引:5,自引:4,他引:1
为了对航空发动机单元体送修工作范围的制定提供决策支持,实现决策的自动化和智能化,在分析航空发动机送修目标的基础上,提出了一种面向目标的单元体送修工作范围决策方法,从时寿件、适航指令/服务通告、硬件损伤、软时限、排气温度裕度五个方面分两步进行单元体送修工作范围的制定.针对决策过程中单元体性能恢复分配存在的难点,建立了以成本最小为目标的优化模型,分别采用动态规划和启发式算法对模型进行了求解,通过对求解结果的比较,给出了两种算法的适用环境.最后将提出的决策方法应用于一个原型系统,在某个航空公司的试用表明了提出的决策方法是有效的,能够满足航空公司的需求. 相似文献
76.
介绍了第二代小波(SGWs)的基本原理和特点,在此基础上提出了低分辨率采样图像高分辨率 (HR)重建算法。它不但具有结构简单,逆变换容易,可扩展性好的优点,并且克服了第一代 小波(FGWs) 的不均匀采样和定义在有限区间上的难题,指出了小波变换时数据不规则性的 处理方法,并利用硬/软阈值对小波系数降噪,使得重构后的图像具有最佳的PSNR和最低的 重构误差。实验和仿真结果表明,与传统方法相比,该算法在提高了图像的分辨率同时PSNR 最多能提高3 dB左右。
相似文献
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77.
78.
Artem L. Ponomarev Alamelu Sundaresan Marcelo E. Vazquez Peter Guida Angela Kim Francis A. Cucinotta 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2011
In heavy ion radiotherapy and space travel humans are exposed to energetic heavy ions (C, Si, Fe and others). This type of irradiation often produces more severe biological effects per unit dose than more common X-rays. A new Monte Carlo model generates a physical space with the complex geometry of human tissue or a cell culture based model of tissue, which is affected by the passage of ionizing radiation. For irradiation, the model relies on a physical code for the ion track structure; for tissues, cellular maps are derived from two- or three-dimensional confocal microscopy images using image segmentation algorithm, which defines cells as pixilated volumes. The model is used to study tissue-specific statistics of direct ion hits and the remote ion action on cells. As an application of the technique, we considered the spatial pattern of apoptotic cells after heavy ion irradiation. The pattern of apoptosis is modeled as a stochastic process, which is defined by the action cross section taken from available experimental data. To characterize the degree of apoptosis, an autocorrelation function that describes the spatial correlation of apoptotic cells is introduced. The values of the autocorrelation function demonstrate the effect of the directionality of the radiation track on the spatial arrangements of inactivated cells in tissue. This effect is intrinsic only to high linear-energy-transfer radiation. 相似文献
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