隐私偏好平台(platform for privacy preferences,P3P)是现今世界上广泛使用的隐私策略语言之一,服务提供者通过P3P隐私策略来告知用户如何处理隐私信息。针对P3P隐私策略缺少形式化语义而难以被精确表达的问题,分析了P3P隐私策略对形...隐私偏好平台(platform for privacy preferences,P3P)是现今世界上广泛使用的隐私策略语言之一,服务提供者通过P3P隐私策略来告知用户如何处理隐私信息。针对P3P隐私策略缺少形式化语义而难以被精确表达的问题,分析了P3P隐私策略对形式化语义的需求以及P3P隐私策略中存在的语义冲突,提出了一种支持冲突检测的data-recipient结构的P3P形式化语义,并用OWL(Web ontology language)本体对该语义进行了描述,阐述了语义冲突的检测方法,并通过实验验证了该方法的可行性。展开更多
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
基金Supported by the National Natural Science Foundation of China under Grant Nos.60375006,60475009(国家自然科学基金)the Research Foundation of North China University of Technology(北方工业大学校科研基金)
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.
