Based on the Jacobian matrices relating the input speeds with the output speeds of linkages, a general method, which is used for solving the singularities of planar multi-loop multi-DOF linkages, is presented. The fou...Based on the Jacobian matrices relating the input speeds with the output speeds of linkages, a general method, which is used for solving the singularities of planar multi-loop multi-DOF linkages, is presented. The four kinds of singularities of 2-DOF planar seven-bar linkages used in hybrid actuators are analyzed in detail by this method. Its five kinds of singular positions whose characteristics are discussed respectively are discovered. Three approaches are proposed on how to avoid the singular positions of planar multi-loop multi-DOF linkages. Based on the assemblability of planar single-loop N-bar chains or linkages, the geometry conditions are investigated and discovered to avoid the singular positions of the linkages. In order to versify aforementioned conclusions, a case is given in which the singular curves are plotted and simulated.展开更多
The manufacturing sector in China has surpassed that of the United States in terms of scale.Yet it still suffers from the shocks of an international economic downturn,the lack of core technologies,and the impact of &q...The manufacturing sector in China has surpassed that of the United States in terms of scale.Yet it still suffers from the shocks of an international economic downturn,the lack of core technologies,and the impact of "re-industrialization" of the developed economies.Based on an evaluation of the "smiling curve" theory and selected trade data from 1991 to 2011,this paper performs a comparative analysis of the differences between the manufacturing sectors of China and those of the traditional manufacturing powers in terms of product categories and architecture.This analysis is conducted in order to explore the question of whether China should transition from being the "world's manufacturing plant" to both ends of the "smiling curve".The paper then introduces Japan's "inverted smiling curve " to explore whether profit margins remain in the manufacturing sector.Research shows that China's manufacturing capacity,especially its "integrated" product assembly capacity,has not been fully realized,and that the development of the manufacturing sector can still yield high market returns.As a result,it is necessary for China to continue the path of being the "world's manufacturing plant".展开更多
文摘Based on the Jacobian matrices relating the input speeds with the output speeds of linkages, a general method, which is used for solving the singularities of planar multi-loop multi-DOF linkages, is presented. The four kinds of singularities of 2-DOF planar seven-bar linkages used in hybrid actuators are analyzed in detail by this method. Its five kinds of singular positions whose characteristics are discussed respectively are discovered. Three approaches are proposed on how to avoid the singular positions of planar multi-loop multi-DOF linkages. Based on the assemblability of planar single-loop N-bar chains or linkages, the geometry conditions are investigated and discovered to avoid the singular positions of the linkages. In order to versify aforementioned conclusions, a case is given in which the singular curves are plotted and simulated.
文摘The manufacturing sector in China has surpassed that of the United States in terms of scale.Yet it still suffers from the shocks of an international economic downturn,the lack of core technologies,and the impact of "re-industrialization" of the developed economies.Based on an evaluation of the "smiling curve" theory and selected trade data from 1991 to 2011,this paper performs a comparative analysis of the differences between the manufacturing sectors of China and those of the traditional manufacturing powers in terms of product categories and architecture.This analysis is conducted in order to explore the question of whether China should transition from being the "world's manufacturing plant" to both ends of the "smiling curve".The paper then introduces Japan's "inverted smiling curve " to explore whether profit margins remain in the manufacturing sector.Research shows that China's manufacturing capacity,especially its "integrated" product assembly capacity,has not been fully realized,and that the development of the manufacturing sector can still yield high market returns.As a result,it is necessary for China to continue the path of being the "world's manufacturing plant".
