基于维度分解思想,设计并实现了一种联合元组空间和位图技术的二维分组分类算法(TB,joint tuple space and bitmap)。TB算法首先分别对源IP地址和目的IP地址进行单维匹配,然后在单维匹配的结果上运用交叉组合形成访问元组空间的路线,最...基于维度分解思想,设计并实现了一种联合元组空间和位图技术的二维分组分类算法(TB,joint tuple space and bitmap)。TB算法首先分别对源IP地址和目的IP地址进行单维匹配,然后在单维匹配的结果上运用交叉组合形成访问元组空间的路线,最后通过位图过滤技术进一步减少访问元组空间的个数,获得最终匹配的多维规则。相比传统的元组空间算法,TB结构清晰简洁易于更新和实现,TB算法拥有更好的时间和空间性能。实验证明,TB算法平均访问内存次数低于代表算法RSFR约26.6%,空间性能平均低于RSFR算法35.1%。展开更多
This paper presents a detailed study on the textural and geochemical characteristics of the proglacial sediments near the edge of modern Nelson Ice Cap, Antarctica. The grain size distributions of the proglacial sedim...This paper presents a detailed study on the textural and geochemical characteristics of the proglacial sediments near the edge of modern Nelson Ice Cap, Antarctica. The grain size distributions of the proglacial sediments are characteristic of glacigenic deposits, but very different from those of aeolian and lacustrine sediments. Moreover, the grain size distributions of the proglacial sediments are fractal with a dimension of about 2.9, and the fractal dimensions can be used as another summary statistical parameter for quantifying the relative amounts of coarse and fine materials. Correlations between the absolute element abundances of the proglacial sediments are very weak due to mineral partitioning and other effects of glacial processes, but correlations between the element/Rb ratios are statistically significant. This finding indicates that element/Rb ratios can be used to reduce or eliminate the effects of glacial processes, evaluate geochemical data and determine the sediment provenance in the foreland of Antarctic glacier. Comparisons on the element concentrations among different environments suggest that the proglacial sediments are derived predominantly from local bedrocks and appear to be natural in origin. Thus these natural sediments can be used to study chemical weathering in the proglacial foreland of modern glacier.展开更多
In this paper, we study the convergence rate of two-dimensional Baakakov operators with Jacobi-weights and the approximation equivalence theorem is obtained, making use of multivariate decompose skills and results of ...In this paper, we study the convergence rate of two-dimensional Baakakov operators with Jacobi-weights and the approximation equivalence theorem is obtained, making use of multivariate decompose skills and results of one-dimensional Baskakov operators.展开更多
A new vortex identification criterion called W-method is proposed based on the ideas that vorticity overtakes deformation in vortex.The comparison with other vortex identification methods like Q-criterion and λ_2-met...A new vortex identification criterion called W-method is proposed based on the ideas that vorticity overtakes deformation in vortex.The comparison with other vortex identification methods like Q-criterion and λ_2-method is conducted and the advantages of the new method can be summarized as follows:(1) the method is able to capture vortex well and very easy to perform;(2) the physical meaning of W is clear while the interpretations of iso-surface values of Q and λ_2 chosen to visualize vortices are obscure;(3)being different from Q and λ_2 iso-surface visualization which requires wildly various thresholds to capture the vortex structure properly, W is pretty universal and does not need much adjustment in different cases and the iso-surfaces of W=0.52 can always capture the vortices properly in all the cases at different time steps, which we investigated;(4) both strong and weak vortices can be captured well simultaneously while improper Q and λ_2 threshold may lead to strong vortex capture while weak vortices are lost or weak vortices are captured but strong vortices are smeared;(5) W=0.52 is a quantity to approximately define the vortex boundary. Note that, to calculate W, the length and velocity must be used in the non-dimensional form. From our direct numerical simulation, it is found that the vorticity direction is very different from the vortex rotation direction in general 3-D vortical flow,the Helmholtz velocity decomposition is reviewed and vorticity is proposed to be further decomposed to vortical vorticity and non-vortical vorticity.展开更多
Let u = （Uh,U3） be a smooth solution of the 3-D Navier-Stokes equations in R3 × [0, T）. It was proved that if u3 ∈ L^∞（0,T;Bp,q-1＋3/p（R3）） for 3 〈 p,q 〈 oe and uh ∈ L^∞（0, T;BMO-1（R3）） with uh（...Let u = （Uh,U3） be a smooth solution of the 3-D Navier-Stokes equations in R3 × [0, T）. It was proved that if u3 ∈ L^∞（0,T;Bp,q-1＋3/p（R3）） for 3 〈 p,q 〈 oe and uh ∈ L^∞（0, T;BMO-1（R3）） with uh（T） ∈ VMO-1（R3）, then u can be extended beyond T. This result generalizes the recent result proved by Gallagher et al. （2016）, which requires u ∈ L^∞（O,T;Bp,^-11＋3/P（R3））. Our proof is based on a new interior regularity criterion in terms of one velocity component, which is independent of interest.展开更多
文摘基于维度分解思想,设计并实现了一种联合元组空间和位图技术的二维分组分类算法(TB,joint tuple space and bitmap)。TB算法首先分别对源IP地址和目的IP地址进行单维匹配,然后在单维匹配的结果上运用交叉组合形成访问元组空间的路线,最后通过位图过滤技术进一步减少访问元组空间的个数,获得最终匹配的多维规则。相比传统的元组空间算法,TB结构清晰简洁易于更新和实现,TB算法拥有更好的时间和空间性能。实验证明,TB算法平均访问内存次数低于代表算法RSFR约26.6%,空间性能平均低于RSFR算法35.1%。
基金The work was supported by the Nationa1 Natural ScienceFoundation of China(Grant No．40231002 and 40076032)the project of Chinese Academy of Sciences(Grant No．KZCX2-303)
文摘This paper presents a detailed study on the textural and geochemical characteristics of the proglacial sediments near the edge of modern Nelson Ice Cap, Antarctica. The grain size distributions of the proglacial sediments are characteristic of glacigenic deposits, but very different from those of aeolian and lacustrine sediments. Moreover, the grain size distributions of the proglacial sediments are fractal with a dimension of about 2.9, and the fractal dimensions can be used as another summary statistical parameter for quantifying the relative amounts of coarse and fine materials. Correlations between the absolute element abundances of the proglacial sediments are very weak due to mineral partitioning and other effects of glacial processes, but correlations between the element/Rb ratios are statistically significant. This finding indicates that element/Rb ratios can be used to reduce or eliminate the effects of glacial processes, evaluate geochemical data and determine the sediment provenance in the foreland of Antarctic glacier. Comparisons on the element concentrations among different environments suggest that the proglacial sediments are derived predominantly from local bedrocks and appear to be natural in origin. Thus these natural sediments can be used to study chemical weathering in the proglacial foreland of modern glacier.
基金Supported by the Scientific Research Fund of Zhejiang Province Education Depart-ment(200700190) Supported by the Science Technique Planed Item of Taizhou City(063KY08)Supported by Major Scientific Research Fund of Taizhou University(09ZD08)
文摘In this paper, we study the convergence rate of two-dimensional Baakakov operators with Jacobi-weights and the approximation equivalence theorem is obtained, making use of multivariate decompose skills and results of one-dimensional Baskakov operators.
基金supported by Air Force Office of Scientific Research (Grant No. FA9550-08-1-0201) supervised by Dr. John Schmisseur and then the Department of Mathematics at University of Texas at Arlington
文摘A new vortex identification criterion called W-method is proposed based on the ideas that vorticity overtakes deformation in vortex.The comparison with other vortex identification methods like Q-criterion and λ_2-method is conducted and the advantages of the new method can be summarized as follows:(1) the method is able to capture vortex well and very easy to perform;(2) the physical meaning of W is clear while the interpretations of iso-surface values of Q and λ_2 chosen to visualize vortices are obscure;(3)being different from Q and λ_2 iso-surface visualization which requires wildly various thresholds to capture the vortex structure properly, W is pretty universal and does not need much adjustment in different cases and the iso-surfaces of W=0.52 can always capture the vortices properly in all the cases at different time steps, which we investigated;(4) both strong and weak vortices can be captured well simultaneously while improper Q and λ_2 threshold may lead to strong vortex capture while weak vortices are lost or weak vortices are captured but strong vortices are smeared;(5) W=0.52 is a quantity to approximately define the vortex boundary. Note that, to calculate W, the length and velocity must be used in the non-dimensional form. From our direct numerical simulation, it is found that the vorticity direction is very different from the vortex rotation direction in general 3-D vortical flow,the Helmholtz velocity decomposition is reviewed and vorticity is proposed to be further decomposed to vortical vorticity and non-vortical vorticity.
基金supported by National Natural Science Foundation of China (Grant Nos. 11301048, 11371039 and 11425103)the Fundamental Research Funds for the Central Universities
文摘Let u = （Uh,U3） be a smooth solution of the 3-D Navier-Stokes equations in R3 × [0, T）. It was proved that if u3 ∈ L^∞（0,T;Bp,q-1＋3/p（R3）） for 3 〈 p,q 〈 oe and uh ∈ L^∞（0, T;BMO-1（R3）） with uh（T） ∈ VMO-1（R3）, then u can be extended beyond T. This result generalizes the recent result proved by Gallagher et al. （2016）, which requires u ∈ L^∞（O,T;Bp,^-11＋3/P（R3））. Our proof is based on a new interior regularity criterion in terms of one velocity component, which is independent of interest.
