We present an efficient three-dimensional coupled-mode model based on the Fourier synthesis technique. In principle, this model is a one-way model, and hence provides satisfactory accuracy for problems where the forwa...We present an efficient three-dimensional coupled-mode model based on the Fourier synthesis technique. In principle, this model is a one-way model, and hence provides satisfactory accuracy for problems where the forward scattering dominates. At the same time, this model provides an efficiency gain of an order of magnitude or more over two-way coupled-mode models. This model can be applied to three-dimensional range-dependent problems with a slowly varying bathymetry or internal waves. A numerical example of the latter is demonstrated in this work. Comparisons of both accuracy and efficiency between the present model and a benchmark model are also provided.展开更多
The application of BEM for solving normal or inverse bio-heat transfer problems of biological bodies with complex shapes is discussed and a new method for non-invasive reconstruction of the spatial temperature field a...The application of BEM for solving normal or inverse bio-heat transfer problems of biological bodies with complex shapes is discussed and a new method for non-invasive reconstruction of the spatial temperature field and the non-homogeneous heat source is proposed in this paper. Tikhonov's (1979) regularization technique is used to improve the performance of ill-posed equations in the process of solving for inverse problems. The feasibility of the above mentioned method was verified by the numerical test results of a two-dimensional steady state problem. This method has laid the theoretical foundation for developing a biomedical instrument and respective software used in the non-invasive monitoring of the spatial temperature field of biological bodies.展开更多
Let G = NwrA be a wreath product of a finite nilpotent group N by an abelian group A. It is shown that every Coleman automorphism of G is an inner automorphism. As an immediate consequence of this result,it is obtaine...Let G = NwrA be a wreath product of a finite nilpotent group N by an abelian group A. It is shown that every Coleman automorphism of G is an inner automorphism. As an immediate consequence of this result,it is obtained that the normalizer property holds for G.展开更多
Suction assisted installation of caisson foundations in sand relies on the developed seepage around the caisson wall.Seepage is known to produce soil loosening inside the caisson cavity and an overall reduction in soi...Suction assisted installation of caisson foundations in sand relies on the developed seepage around the caisson wall.Seepage is known to produce soil loosening inside the caisson cavity and an overall reduction in soil resistance to caisson penetration.On the other hand,suction must be controlled so that no excessive piping is induced within the sand volume trapped inside the caisson cavity.When it extends over the full embedded length of the caisson wall,piping may lead to the formation of piping channels,which may compromise the established seal between caisson and soil and ultimately cause the installation process to stop.A safe installation process requires a proper design procedure to ensure that a safe suction can be predicted prior to installation.The present paper provides a framework where analytical expressions are obtained for the required suction magnitude,and for the critical suction that causes piping to initiate at the caisson tip.These analytical expressions are derived for a normalized caisson geometry,based on compiled results obtained from finite element analysis of seepage around a caisson wall,at various installation depths.The developed analytical formulation applies independently of caisson dimensions such as diameter,height and wall thickness.Critical suction for piping condition is also obtained under analytical form as a function of normalized penetration depth.The developed formulation can also be easily incorporated into design procedures or used in design codes without a need for a preliminary seepage analysis to be undertaken.The proposed suction predictions for the whole process of caisson installation in sand are validated against field trials reported in the literature.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11774374the Natural Science Foundation of Shandong Province of China under Grant No ZR2016AL10
文摘We present an efficient three-dimensional coupled-mode model based on the Fourier synthesis technique. In principle, this model is a one-way model, and hence provides satisfactory accuracy for problems where the forward scattering dominates. At the same time, this model provides an efficiency gain of an order of magnitude or more over two-way coupled-mode models. This model can be applied to three-dimensional range-dependent problems with a slowly varying bathymetry or internal waves. A numerical example of the latter is demonstrated in this work. Comparisons of both accuracy and efficiency between the present model and a benchmark model are also provided.
文摘The application of BEM for solving normal or inverse bio-heat transfer problems of biological bodies with complex shapes is discussed and a new method for non-invasive reconstruction of the spatial temperature field and the non-homogeneous heat source is proposed in this paper. Tikhonov's (1979) regularization technique is used to improve the performance of ill-posed equations in the process of solving for inverse problems. The feasibility of the above mentioned method was verified by the numerical test results of a two-dimensional steady state problem. This method has laid the theoretical foundation for developing a biomedical instrument and respective software used in the non-invasive monitoring of the spatial temperature field of biological bodies.
基金supported by National Natural Science Foundation of China (Grant Nos. 11171169, 11071155)Natural Science Foundation of Shandong Province (Grant No. Y2008A03)Shandong Provincial Education Department (Grant No. J07YH06)
文摘Let G = NwrA be a wreath product of a finite nilpotent group N by an abelian group A. It is shown that every Coleman automorphism of G is an inner automorphism. As an immediate consequence of this result,it is obtained that the normalizer property holds for G.
文摘Suction assisted installation of caisson foundations in sand relies on the developed seepage around the caisson wall.Seepage is known to produce soil loosening inside the caisson cavity and an overall reduction in soil resistance to caisson penetration.On the other hand,suction must be controlled so that no excessive piping is induced within the sand volume trapped inside the caisson cavity.When it extends over the full embedded length of the caisson wall,piping may lead to the formation of piping channels,which may compromise the established seal between caisson and soil and ultimately cause the installation process to stop.A safe installation process requires a proper design procedure to ensure that a safe suction can be predicted prior to installation.The present paper provides a framework where analytical expressions are obtained for the required suction magnitude,and for the critical suction that causes piping to initiate at the caisson tip.These analytical expressions are derived for a normalized caisson geometry,based on compiled results obtained from finite element analysis of seepage around a caisson wall,at various installation depths.The developed analytical formulation applies independently of caisson dimensions such as diameter,height and wall thickness.Critical suction for piping condition is also obtained under analytical form as a function of normalized penetration depth.The developed formulation can also be easily incorporated into design procedures or used in design codes without a need for a preliminary seepage analysis to be undertaken.The proposed suction predictions for the whole process of caisson installation in sand are validated against field trials reported in the literature.