Space double-layer grids are structures that are vulnerable facing progressive collapse phenomenon. So some methods should be studied for space double-layer grids that their collapse behaviors change from a brittle on...Space double-layer grids are structures that are vulnerable facing progressive collapse phenomenon. So some methods should be studied for space double-layer grids that their collapse behaviors change from a brittle one into a soft and ductile. Within this study, than of these structures progressive collapse behavior has been studied. This study answers this question that to which members early to take collapse of double-layer space barrel vaults grids. This research can be identified with the critical members of the progressive failure and overall structural damage avoided.展开更多
We discuss the Oppenheimer-Snyder-Datt (OSD) solution from a new perspective, introduce a completely new formulation of the problem exclusively in external Schwarzschild space-time (ESM) and present a new treatment of...We discuss the Oppenheimer-Snyder-Datt (OSD) solution from a new perspective, introduce a completely new formulation of the problem exclusively in external Schwarzschild space-time (ESM) and present a new treatment of the singularities in this new formulation. We also give a new Newtonian approximation of the problem. Furthermore, we present new numerical solutions of the modified OSD-model and of the ball-to-ball-collapse with 4 different numerical methods.展开更多
In this paper, using incremental equilibrium equation, the authors have studiedthe effeet of ultimate bearing capacity of every component on structuralstability, and discussed the stability analysis method for space c...In this paper, using incremental equilibrium equation, the authors have studiedthe effeet of ultimate bearing capacity of every component on structuralstability, and discussed the stability analysis method for space compositestructures. With the help of the test results for the concrete filled ateel tubeskeleton of the long-spen RC arch bridse, it is proved that the proposed methodis accurate and reliable.展开更多
为了对彩色图像进行快速有效的分割,提出了一种用于分割彩色图像的多尺度形态学算法。该算法首先用基于张量梯度的彩色分水岭算法来得到初始分割结果,即局部水平集连通区域,并综合考虑了面积和色彩计算区域间的相似性,构造了区域间的RAG...为了对彩色图像进行快速有效的分割,提出了一种用于分割彩色图像的多尺度形态学算法。该算法首先用基于张量梯度的彩色分水岭算法来得到初始分割结果,即局部水平集连通区域,并综合考虑了面积和色彩计算区域间的相似性,构造了区域间的RAG(region ad jacency graph)和NNG(nearest ne ighbor nraph),用于后续形态学处理;接着,基于HSV空间中的色彩全序关系,定义了彩色形态算子;然后采用顶点塌缩算法实现的彩色形态学开闭算子生成了所需的非线性尺度空间;最后,利用图像中的极值点与物体间的对应关系,逐级提取图像中包含的物体来得到分层级的表示,并用区域在不同尺度下熵的变化来决定尺度树的构成,从而完成了彩色图像的分割。试验结果表明,该算法不仅具有出色的形状保持能力,而且可提高计算效率。展开更多
文摘Space double-layer grids are structures that are vulnerable facing progressive collapse phenomenon. So some methods should be studied for space double-layer grids that their collapse behaviors change from a brittle one into a soft and ductile. Within this study, than of these structures progressive collapse behavior has been studied. This study answers this question that to which members early to take collapse of double-layer space barrel vaults grids. This research can be identified with the critical members of the progressive failure and overall structural damage avoided.
文摘We discuss the Oppenheimer-Snyder-Datt (OSD) solution from a new perspective, introduce a completely new formulation of the problem exclusively in external Schwarzschild space-time (ESM) and present a new treatment of the singularities in this new formulation. We also give a new Newtonian approximation of the problem. Furthermore, we present new numerical solutions of the modified OSD-model and of the ball-to-ball-collapse with 4 different numerical methods.
文摘In this paper, using incremental equilibrium equation, the authors have studiedthe effeet of ultimate bearing capacity of every component on structuralstability, and discussed the stability analysis method for space compositestructures. With the help of the test results for the concrete filled ateel tubeskeleton of the long-spen RC arch bridse, it is proved that the proposed methodis accurate and reliable.
文摘为了对彩色图像进行快速有效的分割,提出了一种用于分割彩色图像的多尺度形态学算法。该算法首先用基于张量梯度的彩色分水岭算法来得到初始分割结果,即局部水平集连通区域,并综合考虑了面积和色彩计算区域间的相似性,构造了区域间的RAG(region ad jacency graph)和NNG(nearest ne ighbor nraph),用于后续形态学处理;接着,基于HSV空间中的色彩全序关系,定义了彩色形态算子;然后采用顶点塌缩算法实现的彩色形态学开闭算子生成了所需的非线性尺度空间;最后,利用图像中的极值点与物体间的对应关系,逐级提取图像中包含的物体来得到分层级的表示,并用区域在不同尺度下熵的变化来决定尺度树的构成,从而完成了彩色图像的分割。试验结果表明,该算法不仅具有出色的形状保持能力,而且可提高计算效率。
