Box-schemes or organic food subscription plans consist on a regular delivery of a box of seasonal fruits and/or vegetables, preferably organic, cultivated in the vicinity at a specified point using subscription, The o...Box-schemes or organic food subscription plans consist on a regular delivery of a box of seasonal fruits and/or vegetables, preferably organic, cultivated in the vicinity at a specified point using subscription, The object of the present work is trying to examine whether there is a relationship between consumer knowledge about these short distribution channels and the consumption of organic products in the province of Alicante. A survey has been conducted among 400 usual food buyers in this Spanish province. It has been found that the consumption of organic products and the knowledge of such initiatives are linked. We recommend to companies that use this type of distribution channel to publicize its benefits.展开更多
In this paper the problem−div(a(x,y)∇u)=f with Dirichlet boundary conditions on a square is solved iteratively with high accuracy for u and∇u using a new scheme called“hermitian box-scheme”.The design of the scheme ...In this paper the problem−div(a(x,y)∇u)=f with Dirichlet boundary conditions on a square is solved iteratively with high accuracy for u and∇u using a new scheme called“hermitian box-scheme”.The design of the scheme is based on a“hermitian box”,combining the approximation of the gradient by the fourth order hermitian derivative,with a conservative discrete formulation on boxes of length 2h.The iterative technique is based on the repeated solution by a fast direct method of a discrete Poisson equation on a uniform rectangular mesh.The problem is suitably scaled before iteration.The numerical results obtained show the efficiency of the numerical scheme.This work is the extension to strongly elliptic problems of the hermitian box-scheme presented by Abbas and Croisille(J.Sci.Comput.,49(2011),pp.239–267).展开更多
We derive a new multisymplectic integrator for the Kawahara-type equation which is a fully explicit scheme and thus needs less computation cost. Multisympecticity of such scheme guarantees the long-time numerical beha...We derive a new multisymplectic integrator for the Kawahara-type equation which is a fully explicit scheme and thus needs less computation cost. Multisympecticity of such scheme guarantees the long-time numerical behaviors. Nu- merical experiments are presented to verify the accuracy of this scheme as well as the excellent performance on invariant preservation for three kinds of Kawahara-type equations.展开更多
文摘Box-schemes or organic food subscription plans consist on a regular delivery of a box of seasonal fruits and/or vegetables, preferably organic, cultivated in the vicinity at a specified point using subscription, The object of the present work is trying to examine whether there is a relationship between consumer knowledge about these short distribution channels and the consumption of organic products in the province of Alicante. A survey has been conducted among 400 usual food buyers in this Spanish province. It has been found that the consumption of organic products and the knowledge of such initiatives are linked. We recommend to companies that use this type of distribution channel to publicize its benefits.
文摘In this paper the problem−div(a(x,y)∇u)=f with Dirichlet boundary conditions on a square is solved iteratively with high accuracy for u and∇u using a new scheme called“hermitian box-scheme”.The design of the scheme is based on a“hermitian box”,combining the approximation of the gradient by the fourth order hermitian derivative,with a conservative discrete formulation on boxes of length 2h.The iterative technique is based on the repeated solution by a fast direct method of a discrete Poisson equation on a uniform rectangular mesh.The problem is suitably scaled before iteration.The numerical results obtained show the efficiency of the numerical scheme.This work is the extension to strongly elliptic problems of the hermitian box-scheme presented by Abbas and Croisille(J.Sci.Comput.,49(2011),pp.239–267).
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11271195 and 11271196)the Project of Graduate Education Innovation of Jiangsu Province,China(Grant No.CXZZ12-0385)
文摘We derive a new multisymplectic integrator for the Kawahara-type equation which is a fully explicit scheme and thus needs less computation cost. Multisympecticity of such scheme guarantees the long-time numerical behaviors. Nu- merical experiments are presented to verify the accuracy of this scheme as well as the excellent performance on invariant preservation for three kinds of Kawahara-type equations.
