The roughness of the model function f(x) to the basis functions has been identified. When the model function is continuous segment, its roughness does not depend on the behavior of the first segment, but depends on ...The roughness of the model function f(x) to the basis functions has been identified. When the model function is continuous segment, its roughness does not depend on the behavior of the first segment, but depends on "h", the shift in the slope of two consecutive segments. If the distribution of design is uniform, f(x) is continuous segment function, and h is constant, then the maximum roughness is h2/192 obtained at the midpoint of the observations. Suppose that we have a sequence of designs {Pn(x)} then its corresponding distribution {Fn (x)} converges weakly to some distribution F(x). Let D(f) be a set of discontinuous points off(x), it is possible to take the limit of the roughness if D(f) has zero (dF)-measure. The behavior of maximum roughness of the discontinuous segment function has been studied by using grid points.展开更多
The wave diffraction and radiation around a floating body is considered within the framework of the linear potential theory in a fairly perfect fluid. The fluid domain extended infinitely in the horizontal directions ...The wave diffraction and radiation around a floating body is considered within the framework of the linear potential theory in a fairly perfect fluid. The fluid domain extended infinitely in the horizontal directions but is limited by the sea bed, the body hull, and the part of the free surface excluding the body waterplane, and is subdivided into two subdomains according to the body geometry. The two subdomains are connected by a control surface in fluid. In each subdomain, the velocity potential is described by using the usual boundary integral representation involving Green functions. The boundary integral equations are then established by satisfying the boundary conditions and the continuous condition of the potential and the normal derivation across the control surface. This multi-domain boundary element method (MDBEM) is particularly interesting for bodies with a hull form including moonpools to which the usual BEM presents singularities and slow convergence of numerical results. The application of the MDBEM to study the resonant motion of a water column in moonpools shows that the MDBEM provides an efficient and reliable prediction method.展开更多
A mistake in Proposition I-1.21.1 of 'A Compendium of Continuous Lattices'by G.Giers et al. is pointed out and a revised proposition with a proof is given.
文摘The roughness of the model function f(x) to the basis functions has been identified. When the model function is continuous segment, its roughness does not depend on the behavior of the first segment, but depends on "h", the shift in the slope of two consecutive segments. If the distribution of design is uniform, f(x) is continuous segment function, and h is constant, then the maximum roughness is h2/192 obtained at the midpoint of the observations. Suppose that we have a sequence of designs {Pn(x)} then its corresponding distribution {Fn (x)} converges weakly to some distribution F(x). Let D(f) be a set of discontinuous points off(x), it is possible to take the limit of the roughness if D(f) has zero (dF)-measure. The behavior of maximum roughness of the discontinuous segment function has been studied by using grid points.
文摘The wave diffraction and radiation around a floating body is considered within the framework of the linear potential theory in a fairly perfect fluid. The fluid domain extended infinitely in the horizontal directions but is limited by the sea bed, the body hull, and the part of the free surface excluding the body waterplane, and is subdivided into two subdomains according to the body geometry. The two subdomains are connected by a control surface in fluid. In each subdomain, the velocity potential is described by using the usual boundary integral representation involving Green functions. The boundary integral equations are then established by satisfying the boundary conditions and the continuous condition of the potential and the normal derivation across the control surface. This multi-domain boundary element method (MDBEM) is particularly interesting for bodies with a hull form including moonpools to which the usual BEM presents singularities and slow convergence of numerical results. The application of the MDBEM to study the resonant motion of a water column in moonpools shows that the MDBEM provides an efficient and reliable prediction method.
基金Supported by National Natlural Science Foundation of China
文摘A mistake in Proposition I-1.21.1 of 'A Compendium of Continuous Lattices'by G.Giers et al. is pointed out and a revised proposition with a proof is given.