Segmentation of three-dimensional(3D) complicated structures is of great importance for many real applications.In this work we combine graph cut minimization method with a variant of the level set idea for 3D segmenta...Segmentation of three-dimensional(3D) complicated structures is of great importance for many real applications.In this work we combine graph cut minimization method with a variant of the level set idea for 3D segmentation based on the Mumford-Shah model.Compared with the traditional approach for solving the Euler-Lagrange equation we do not need to solve any partial differential equations.Instead,the minimum cut on a special designed graph need to be computed.The method is tested on data with complicated structures.It is rather stable with respect to initial value and the algorithm is nearly parameter free.Experiments show that it can solve large problems much faster than traditional approaches.展开更多
Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures (VLFSs) and create additional connector loads. In this study, the combined effects of ship collision...Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures (VLFSs) and create additional connector loads. In this study, the combined effects of ship collision and wave loads are considered to establish motion differential equations for a multi-body VLFS. A time domain calculation method is proposed to calculate the connector load of the VLFS in waves. The Longuet-Higgins model is employed to simulate the stochastic wave load. Fluid force and hydrodynamic coefficient are obtained with DNV Sesam software. The motion differential equation is calculated by applying the time domain method when the frequency domain hydrodynamic coefficient is converted into the memory function of the motion differential equation of the time domain. As a result of the combined action of wave and impact loads, high-frequency oscillation is observed in the time history curve of the connector load. At wave directions of 0° and 75°, the regularities of the time history curves of the connector loads in different directions are similar and the connector loads of C1 and C2 in the X direction are the largest. The oscillation load is observed in the connector in the Y direction at a wave direction of 75° and not at 0° This paper presents a time domain calculation method of connector load to provide a certain reference function for the future development of Chinese VLFS展开更多
We derive the generalized dromions of the new (2 + 1)-dimensional nonlinear evolution equation by the arbitrary function presented in the bilinearized linear equations. The rich soliton and dromion structures for this...We derive the generalized dromions of the new (2 + 1)-dimensional nonlinear evolution equation by the arbitrary function presented in the bilinearized linear equations. The rich soliton and dromion structures for this system are released.展开更多
Starting from a Backlund transformation and taking a special ansatz for the function f, we can obtain a much more generalexpression of solution that includes some variable separated functions for the higher-order Broe...Starting from a Backlund transformation and taking a special ansatz for the function f, we can obtain a much more generalexpression of solution that includes some variable separated functions for the higher-order Broer-Kaup system. From this expression, we investigate the interactions of localized coherent structures such as the multi-solitonic excitations and find the novel phenomenon that their interactions have non-elastic behavior because the fission/fusion may occur after the interaction of each localized coherent structure.展开更多
A simple shallow-water model with influence of external forcing on a β-planeis applied to investigate the nonlinear equatorial Rossby waves in a shear flow. By theperturbation method, the extended variable-coefficien...A simple shallow-water model with influence of external forcing on a β-planeis applied to investigate the nonlinear equatorial Rossby waves in a shear flow. By theperturbation method, the extended variable-coefficient KdV equation under an external forcing isderived for large amplitude equatorial Rossby wave in a shear How. And then various periodic-likestructures for these equatorial Rossby waves are obtained with the help of Jacobi ellipticfunctions. It is shown that the external forcing plays an important role in various periodic-likestructures.展开更多
The isospectral problem of the second mKdV equation is found out firstly. It follows that the strong hereditary symmetry and the Hamiltonian structure of the second mKdV equation are presented.
This paper introduces the use of partition of unity method for the development of a high order finite volume discretization scheme on unstructured grids for solving diffusion models based on partial differential equat...This paper introduces the use of partition of unity method for the development of a high order finite volume discretization scheme on unstructured grids for solving diffusion models based on partial differential equations.The unknown function and its gradient can be accurately reconstructed using high order optimal recovery based on radial basis functions.The methodology proposed is applied to the noise removal problem in functional surfaces and images.Numerical results demonstrate the effectiveness of the new numerical approach and provide experimental order of convergence.展开更多
Starting from iterated systems, it is shown that the homoclinic (heteroclinic) orbit is a kind of spiral structure. The emphasis is laid to show that there are homoclinic or heteroclinic orbits in complex discrete and...Starting from iterated systems, it is shown that the homoclinic (heteroclinic) orbit is a kind of spiral structure. The emphasis is laid to show that there are homoclinic or heteroclinic orbits in complex discrete and continuous systems, and these homoclinic or heteroclinic orbits are some kind of spiral structure.展开更多
Based on the variational prineiple of incomplete generalized potential energy with large deflection, the vertical nonlinear vibrational differential equation of self-anchored suspension bridge is presented by taking t...Based on the variational prineiple of incomplete generalized potential energy with large deflection, the vertical nonlinear vibrational differential equation of self-anchored suspension bridge is presented by taking the effect of coupling of flexural and axial action into consideration. The linear vertical equation is obtained by omitting the nonlinear term, and the pseudo excitation method(PEM). Taking the self-anchored concrete suspension bridge over Lanqi Songhua river for an example, the expected peak responses of main beam, towers and cables are calculated. And the seismic spatial effects on vertical seismic response of self-anchored suspension bridges are discussed.展开更多
This paper studies the dynamical behavior of a class of total area dependent nonlinear age-structured forest evolution model. We give the problem of equal value for the forest system, and discuss the stable solution o...This paper studies the dynamical behavior of a class of total area dependent nonlinear age-structured forest evolution model. We give the problem of equal value for the forest system, and discuss the stable solution of system. We obtained the necessary and sufficient conditions for there exists the stable solution.展开更多
A class of two-level high-order accuracy explicit difference scheme for solving 3-D parabolic P.D.E is constructed. Its truncation error is (Δt2+Δx4) and the stability condition is r=Δt/Δx2=Δt/Δy2=Δt/Δz2≤1/6.
There are several important generalizations of martingales such as games fairer with time, quasi-mils and sequential martingales in the limit. In the note, we shall consider all possible structures of a probability sp...There are several important generalizations of martingales such as games fairer with time, quasi-mils and sequential martingales in the limit. In the note, we shall consider all possible structures of a probability space (Ω,A, (An), P) associated with a stochastic basis(An) of sub a-fields of A with An ↑ A. Then, we shall apply them to establish some comparison results for the aforementioned generalizations of martingales.展开更多
Recently the mass and the basic structure of SM Higgs boson (H^0) have been discussed by the author with obtaining asymptotic solution for the equation of motion of nonlinear Klein-Gordon type partial differential e...Recently the mass and the basic structure of SM Higgs boson (H^0) have been discussed by the author with obtaining asymptotic solution for the equation of motion of nonlinear Klein-Gordon type partial differential equation. In this paper, we will treat with above in mind: masses of glueball (GB) of ground state and of certain fo mesons, ur, Higgs boson (ur-H^0) which will consist of a number of GBs and/or fo above for respective fullerene structure, a representation of these fo mesons' masses by masses of n octet and GB, and transformation of ur-H^0 into H^0.展开更多
Let G be arbitrary finite group,define H G· (t;p +,p) to be the generating function of G-wreath double Hurwitz numbers.We prove that H G· (t;p +,p) satisfies a differential equation called the colored cutand...Let G be arbitrary finite group,define H G· (t;p +,p) to be the generating function of G-wreath double Hurwitz numbers.We prove that H G· (t;p +,p) satisfies a differential equation called the colored cutand-join equation.Furthermore,H G·(t;p +,p) is a product of several copies of tau functions of the 2-Toda hierarchy,in independent variables.These generalize the corresponding results for ordinary Hurwitz numbers.展开更多
Soil aggregation and organic matter of soils from the pre-Pyrenean range in Catalonia (NE Spain) were studied,in order to assess their quality as carbon sinks and also to select the best soil management practices to p...Soil aggregation and organic matter of soils from the pre-Pyrenean range in Catalonia (NE Spain) were studied,in order to assess their quality as carbon sinks and also to select the best soil management practices to preserve their quality.Aggregate stability,organic carbon and micromorphology were investigated.The highest amount of organic carbon was found in alluvial,deep soils (228 Mg C ha -1 ),and the lowest was in a shallow,stony soil with a low plant cover (78 Mg C ha -1 ).Subsurface horizons of degraded soils under pastures were the ones with smaller and less-stable aggregates.Fresh residues of organic matter (OM) were found mostly in interaggregate spaces.Within the aggregates there were some organic remains that were beginning to decompose,and also impregnative nodules of amorphous OM.Although OM was evenly distributed among the aggregate fractions,the larger blocky peds had more specific surface,contained less decomposed OM and had a lower organic/mineral interphase than smaller crumb aggregates,which were also more stable.Soil carbon storage was affected primarily by the OM inputs in the surface horizons.In order to store organic carbon over the mid- and long-term periods,the mechanisms favouring structuration through biological activity and creating small aggregates with intrapedal stable microporosities seemed to be the most effective.展开更多
A large class of stochastic differential games for several players is considered in this paper.The class includes Nash differential games as well as Stackelberg differential games.A mix is possible.The existence of fe...A large class of stochastic differential games for several players is considered in this paper.The class includes Nash differential games as well as Stackelberg differential games.A mix is possible.The existence of feedback strategies under general conditions is proved.The limitations concern the functionals in which the state and the controls appear separately.This is also true for the state equations.The controls appear in a quadratic form for the payoff and linearly in the state equation.The most serious restriction is the dimension of the state equation,which cannot exceed 2.The reason comes from PDE(partial differential equations) techniques used in studying the system of Bellman equations obtained by Dynamic Programming arguments.In the authors' previous work in 2002,there is not such a restriction,but there are serious restrictions on the structure of the Hamiltonians,which are violated in the applications dealt with in this article.展开更多
基金support from the Centre for Integrated Petroleum Research(CIPR),University of Bergen, Norway,and Singapore MOE Grant T207B2202NRF2007IDMIDM002-010
文摘Segmentation of three-dimensional(3D) complicated structures is of great importance for many real applications.In this work we combine graph cut minimization method with a variant of the level set idea for 3D segmentation based on the Mumford-Shah model.Compared with the traditional approach for solving the Euler-Lagrange equation we do not need to solve any partial differential equations.Instead,the minimum cut on a special designed graph need to be computed.The method is tested on data with complicated structures.It is rather stable with respect to initial value and the algorithm is nearly parameter free.Experiments show that it can solve large problems much faster than traditional approaches.
基金Foundation item: Supported by the National Natural Science Foundation of China (51309123), National Key Basic Research and Development Plan (973 Plan, 2013CB036104), Jiangsu Province Natural Science Research Projects in Colleges and Universities (13KJB570002), Open Foundation of State Key Laboratory of Ocean Engineering (1407), "Qing Lan Project" of Colleges and Universities in Jiangsu Province, Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
文摘Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures (VLFSs) and create additional connector loads. In this study, the combined effects of ship collision and wave loads are considered to establish motion differential equations for a multi-body VLFS. A time domain calculation method is proposed to calculate the connector load of the VLFS in waves. The Longuet-Higgins model is employed to simulate the stochastic wave load. Fluid force and hydrodynamic coefficient are obtained with DNV Sesam software. The motion differential equation is calculated by applying the time domain method when the frequency domain hydrodynamic coefficient is converted into the memory function of the motion differential equation of the time domain. As a result of the combined action of wave and impact loads, high-frequency oscillation is observed in the time history curve of the connector load. At wave directions of 0° and 75°, the regularities of the time history curves of the connector loads in different directions are similar and the connector loads of C1 and C2 in the X direction are the largest. The oscillation load is observed in the connector in the Y direction at a wave direction of 75° and not at 0° This paper presents a time domain calculation method of connector load to provide a certain reference function for the future development of Chinese VLFS
文摘We derive the generalized dromions of the new (2 + 1)-dimensional nonlinear evolution equation by the arbitrary function presented in the bilinearized linear equations. The rich soliton and dromion structures for this system are released.
文摘Starting from a Backlund transformation and taking a special ansatz for the function f, we can obtain a much more generalexpression of solution that includes some variable separated functions for the higher-order Broer-Kaup system. From this expression, we investigate the interactions of localized coherent structures such as the multi-solitonic excitations and find the novel phenomenon that their interactions have non-elastic behavior because the fission/fusion may occur after the interaction of each localized coherent structure.
文摘A simple shallow-water model with influence of external forcing on a β-planeis applied to investigate the nonlinear equatorial Rossby waves in a shear flow. By theperturbation method, the extended variable-coefficient KdV equation under an external forcing isderived for large amplitude equatorial Rossby wave in a shear How. And then various periodic-likestructures for these equatorial Rossby waves are obtained with the help of Jacobi ellipticfunctions. It is shown that the external forcing plays an important role in various periodic-likestructures.
基金The project supported by National Natural Science Foundation of China under Grant No. 10371070, the Youth Foundation of Shanghai Education Committee and the Special Funds for Major Specialities of Shanghai Education Committee .The first author expresses her appreciations to the soliton disquisitive team of Shanghai University for their useful discussions.
文摘The isospectral problem of the second mKdV equation is found out firstly. It follows that the strong hereditary symmetry and the Hamiltonian structure of the second mKdV equation are presented.
基金supported by PRIN-MIUR-Cofin 2006by University of Bologna"Funds for selected research topics"
文摘This paper introduces the use of partition of unity method for the development of a high order finite volume discretization scheme on unstructured grids for solving diffusion models based on partial differential equations.The unknown function and its gradient can be accurately reconstructed using high order optimal recovery based on radial basis functions.The methodology proposed is applied to the noise removal problem in functional surfaces and images.Numerical results demonstrate the effectiveness of the new numerical approach and provide experimental order of convergence.
文摘Starting from iterated systems, it is shown that the homoclinic (heteroclinic) orbit is a kind of spiral structure. The emphasis is laid to show that there are homoclinic or heteroclinic orbits in complex discrete and continuous systems, and these homoclinic or heteroclinic orbits are some kind of spiral structure.
文摘Based on the variational prineiple of incomplete generalized potential energy with large deflection, the vertical nonlinear vibrational differential equation of self-anchored suspension bridge is presented by taking the effect of coupling of flexural and axial action into consideration. The linear vertical equation is obtained by omitting the nonlinear term, and the pseudo excitation method(PEM). Taking the self-anchored concrete suspension bridge over Lanqi Songhua river for an example, the expected peak responses of main beam, towers and cables are calculated. And the seismic spatial effects on vertical seismic response of self-anchored suspension bridges are discussed.
文摘This paper studies the dynamical behavior of a class of total area dependent nonlinear age-structured forest evolution model. We give the problem of equal value for the forest system, and discuss the stable solution of system. We obtained the necessary and sufficient conditions for there exists the stable solution.
文摘A class of two-level high-order accuracy explicit difference scheme for solving 3-D parabolic P.D.E is constructed. Its truncation error is (Δt2+Δx4) and the stability condition is r=Δt/Δx2=Δt/Δy2=Δt/Δz2≤1/6.
基金Supported by the Natural Science Foundation of the Education Department of Henan province(200510483002)
文摘There are several important generalizations of martingales such as games fairer with time, quasi-mils and sequential martingales in the limit. In the note, we shall consider all possible structures of a probability space (Ω,A, (An), P) associated with a stochastic basis(An) of sub a-fields of A with An ↑ A. Then, we shall apply them to establish some comparison results for the aforementioned generalizations of martingales.
文摘Recently the mass and the basic structure of SM Higgs boson (H^0) have been discussed by the author with obtaining asymptotic solution for the equation of motion of nonlinear Klein-Gordon type partial differential equation. In this paper, we will treat with above in mind: masses of glueball (GB) of ground state and of certain fo mesons, ur, Higgs boson (ur-H^0) which will consist of a number of GBs and/or fo above for respective fullerene structure, a representation of these fo mesons' masses by masses of n octet and GB, and transformation of ur-H^0 into H^0.
基金supported by National Natural Science Foundation of China(Grant Nos.10425101,10631050)National Basic Research Program of China(973Project)(Grant No.2006cB805905)
文摘Let G be arbitrary finite group,define H G· (t;p +,p) to be the generating function of G-wreath double Hurwitz numbers.We prove that H G· (t;p +,p) satisfies a differential equation called the colored cutand-join equation.Furthermore,H G·(t;p +,p) is a product of several copies of tau functions of the 2-Toda hierarchy,in independent variables.These generalize the corresponding results for ordinary Hurwitz numbers.
基金Supported by the Ministry of Education and Science of Spain (No. SUM2006-00029-C02)
文摘Soil aggregation and organic matter of soils from the pre-Pyrenean range in Catalonia (NE Spain) were studied,in order to assess their quality as carbon sinks and also to select the best soil management practices to preserve their quality.Aggregate stability,organic carbon and micromorphology were investigated.The highest amount of organic carbon was found in alluvial,deep soils (228 Mg C ha -1 ),and the lowest was in a shallow,stony soil with a low plant cover (78 Mg C ha -1 ).Subsurface horizons of degraded soils under pastures were the ones with smaller and less-stable aggregates.Fresh residues of organic matter (OM) were found mostly in interaggregate spaces.Within the aggregates there were some organic remains that were beginning to decompose,and also impregnative nodules of amorphous OM.Although OM was evenly distributed among the aggregate fractions,the larger blocky peds had more specific surface,contained less decomposed OM and had a lower organic/mineral interphase than smaller crumb aggregates,which were also more stable.Soil carbon storage was affected primarily by the OM inputs in the surface horizons.In order to store organic carbon over the mid- and long-term periods,the mechanisms favouring structuration through biological activity and creating small aggregates with intrapedal stable microporosities seemed to be the most effective.
基金supported by DAAD-PPP Hong Kong/Germany (No. G. HK 036/09)
文摘A large class of stochastic differential games for several players is considered in this paper.The class includes Nash differential games as well as Stackelberg differential games.A mix is possible.The existence of feedback strategies under general conditions is proved.The limitations concern the functionals in which the state and the controls appear separately.This is also true for the state equations.The controls appear in a quadratic form for the payoff and linearly in the state equation.The most serious restriction is the dimension of the state equation,which cannot exceed 2.The reason comes from PDE(partial differential equations) techniques used in studying the system of Bellman equations obtained by Dynamic Programming arguments.In the authors' previous work in 2002,there is not such a restriction,but there are serious restrictions on the structure of the Hamiltonians,which are violated in the applications dealt with in this article.