Image segmentation is a key and fundamental problem in image processing,computer graphics,and computer vision.Level set based method for image segmentation is used widely for its topology flexibility and proper mathem...Image segmentation is a key and fundamental problem in image processing,computer graphics,and computer vision.Level set based method for image segmentation is used widely for its topology flexibility and proper mathematical formulation.However,poor performance of existing level set models on noisy images and weak boundary limit its application in image segmentation.In this paper,we present a region consistency constraint term to measure the regional consistency on both sides of the boundary,this term defines the boundary of the image within a range,and hence increases the stability of the level set model.The term can make existing level set models significantly improve the efficiency of the algorithms on segmenting images with noise and weak boundary.Furthermore,this constraint term can make edge-based level set model overcome the defect of sensitivity to the initial contour.The experimental results show that our algorithm is efficient for image segmentation and outperform the existing state-of-art methods regarding images with noise and weak boundary.展开更多
We study the consistency conditions of the generalized f ( R) gravity by extending f ( R) gravity with non-minimal coupling to the generalized f(R) with arbitrary geometry-matter coupling. Specifically, we discu...We study the consistency conditions of the generalized f ( R) gravity by extending f ( R) gravity with non-minimal coupling to the generalized f(R) with arbitrary geometry-matter coupling. Specifically, we discuss the two particular models of generalized f(R) by means of consistency conditions. It is found that the second model is not physically viable so as to be ruled out. Moreover, we further constrain the first model using the Dolgov- Kawasaki stability criterion, and give the value ranges of the parameters in the first model It is worth stressing that our results include the ones in f(R) gravity with non-minimal coupling as the special case of Q(Lm) = Lm.展开更多
This article presents a systematic research methodology of modular design for conceptual auto body frame by hybrid optimization method.A modified graph-based decomposition optimization algorithm is utilized to generat...This article presents a systematic research methodology of modular design for conceptual auto body frame by hybrid optimization method.A modified graph-based decomposition optimization algorithm is utilized to generate an optimal BIW assembly topo model composed of“potential modules”.The consistency constraint function in collaborative optimization is extended to maximize the commonality of modules and minimize the performance loss of all car types in the same product family simultaneously.A novel screening method is employed to select both“basic structures”and“reinforcement”modules based on the dimension optimization of the manufacturing elements and the optimal assembly mode;this allows for a more exhaustive modular platform design in contrast with existing methods.The proposed methodology is applied to a case study for the modular design of three conceptual auto body types in the same platform to validate its feasibility and effectiveness.展开更多
In this thesis, the interal relations between about shear looking, zero energy mode and patch test are studied, and a reasonable method provided for building general element of thick and thin plate with effectual and ...In this thesis, the interal relations between about shear looking, zero energy mode and patch test are studied, and a reasonable method provided for building general element of thick and thin plate with effectual and realiable numerical solution.展开更多
基金supported in part by the NSFC-Zhejiang Joint Fund of the Integration of Informatization and Industrialization(U1609218)NSFC(61772312,61373078,61772253)+1 种基金the Key Research and Development Project of Shandong Province(2017GGX10110)NSF of Shandong Province(ZR2016FM21,ZR2016FM13)
文摘Image segmentation is a key and fundamental problem in image processing,computer graphics,and computer vision.Level set based method for image segmentation is used widely for its topology flexibility and proper mathematical formulation.However,poor performance of existing level set models on noisy images and weak boundary limit its application in image segmentation.In this paper,we present a region consistency constraint term to measure the regional consistency on both sides of the boundary,this term defines the boundary of the image within a range,and hence increases the stability of the level set model.The term can make existing level set models significantly improve the efficiency of the algorithms on segmenting images with noise and weak boundary.Furthermore,this constraint term can make edge-based level set model overcome the defect of sensitivity to the initial contour.The experimental results show that our algorithm is efficient for image segmentation and outperform the existing state-of-art methods regarding images with noise and weak boundary.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11175077,11575075 and 11547156the Joint Specialized Research Fund for the Doctoral Program of Higher Education of Ministry of Education of China under Grant No 20122136110002+1 种基金the Open Project Program of State Key Laboratory of Theoretical Physics of Institute of Theoretical Physics under Grant No Y4KF101CJ1the Project of Key Discipline of Theoretical Physics of Department of Education in Liaoning Province under Grant Nos 905035 and 905061
文摘We study the consistency conditions of the generalized f ( R) gravity by extending f ( R) gravity with non-minimal coupling to the generalized f(R) with arbitrary geometry-matter coupling. Specifically, we discuss the two particular models of generalized f(R) by means of consistency conditions. It is found that the second model is not physically viable so as to be ruled out. Moreover, we further constrain the first model using the Dolgov- Kawasaki stability criterion, and give the value ranges of the parameters in the first model It is worth stressing that our results include the ones in f(R) gravity with non-minimal coupling as the special case of Q(Lm) = Lm.
基金This work was funded by the Innovation Foundation of GAC R&D Center.
文摘This article presents a systematic research methodology of modular design for conceptual auto body frame by hybrid optimization method.A modified graph-based decomposition optimization algorithm is utilized to generate an optimal BIW assembly topo model composed of“potential modules”.The consistency constraint function in collaborative optimization is extended to maximize the commonality of modules and minimize the performance loss of all car types in the same product family simultaneously.A novel screening method is employed to select both“basic structures”and“reinforcement”modules based on the dimension optimization of the manufacturing elements and the optimal assembly mode;this allows for a more exhaustive modular platform design in contrast with existing methods.The proposed methodology is applied to a case study for the modular design of three conceptual auto body types in the same platform to validate its feasibility and effectiveness.
文摘In this thesis, the interal relations between about shear looking, zero energy mode and patch test are studied, and a reasonable method provided for building general element of thick and thin plate with effectual and realiable numerical solution.