The PnP problem is a widely used technique for pose determination in computer vision community,and finding out geometric conditions of multiple solutions is the ultimate and most desirable goal of the multi-solution a...The PnP problem is a widely used technique for pose determination in computer vision community,and finding out geometric conditions of multiple solutions is the ultimate and most desirable goal of the multi-solution analysis,which is also a key research issue of the problem.In this paper,we prove that given 3 control points,if the camera's optical center lies on the so-called“danger cylinder”and is enough far from the supporting plane of control points,the corresponding P3P problem must have 3 positive solutions.This result can bring some new insights into a better understanding of the multi-solution problem.For example,it is shown in the literature that the solution of the P3P problem is instable if the optical center lies on this danger cylinder,we think such occurrence of triple-solution is the primary source of this instability.展开更多
The large and persistent U.S.trade deficit with China,which reached$233 billion in 2006,is causing increased tension in China-U.S.relations.A new coalition has arisen between hawks on Capitol Hill,who see China as a s...The large and persistent U.S.trade deficit with China,which reached$233 billion in 2006,is causing increased tension in China-U.S.relations.A new coalition has arisen between hawks on Capitol Hill,who see China as a security threat,and protectionists,who blame China for"stealing"American jobs through"unfair trade practices."James A.Dorn,China specialist and Vice President for academic affairs at the Cato Institute in Washington,D.C., however,warns,imposing trade sanctions on China would not eliminate the U.S.bilateral trade deficit-but would endanger the global liberal trading order.Correcting trade imbalances requires flexibility,not rigidity,he says.展开更多
Unlike special interest groups that are harmed by trade, no one represents future generations who will have a lower standard of living because of present government profligacy
基金Supported by"973"Program(2002CB312104)National Natural Science Foundation of P.R.China(60375006)the Research Foundation of North China Unversity of Technology University
文摘The PnP problem is a widely used technique for pose determination in computer vision community,and finding out geometric conditions of multiple solutions is the ultimate and most desirable goal of the multi-solution analysis,which is also a key research issue of the problem.In this paper,we prove that given 3 control points,if the camera's optical center lies on the so-called“danger cylinder”and is enough far from the supporting plane of control points,the corresponding P3P problem must have 3 positive solutions.This result can bring some new insights into a better understanding of the multi-solution problem.For example,it is shown in the literature that the solution of the P3P problem is instable if the optical center lies on this danger cylinder,we think such occurrence of triple-solution is the primary source of this instability.
文摘The large and persistent U.S.trade deficit with China,which reached$233 billion in 2006,is causing increased tension in China-U.S.relations.A new coalition has arisen between hawks on Capitol Hill,who see China as a security threat,and protectionists,who blame China for"stealing"American jobs through"unfair trade practices."James A.Dorn,China specialist and Vice President for academic affairs at the Cato Institute in Washington,D.C., however,warns,imposing trade sanctions on China would not eliminate the U.S.bilateral trade deficit-but would endanger the global liberal trading order.Correcting trade imbalances requires flexibility,not rigidity,he says.
文摘Unlike special interest groups that are harmed by trade, no one represents future generations who will have a lower standard of living because of present government profligacy
