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排序方式: 共有363条查询结果,搜索用时 796 毫秒
31.
Brahim El Khalil Hachi Said Rechak Mohamed Haboussi Mbarek Taghite 《Comptes Rendus Mecanique》2006,334(1):83-90
A method improving the evaluation of the stress intensity factor by hybridization of two weight functions is presented and applied to embedded elliptical cracks under various loadings. The hybridization consists in using one or the other function in the zone of the crack where it is the most efficient. The delimitation of the two zones is achieved after optimizing the axes ratio and the curvature radius of the crack. During this optimization we seek to reduce the effects of the singularities present in the weight functions as well as to take better into account the influence of the ellipse curvature. To cite this article: B. El Khalil Hachi et al., C. R. Mecanique 334 (2006). 相似文献
32.
An asymptotic analysis is presented for a dynamic problem of a semi-infinite isotropic thermoelastic solid with a small surface breaking crack. The exterior surface of the solid is subjected to a series of short thermal pulses. The crack surface is traction free and an ideal thermal contact is assumed across the crack. The stress intensity factor is asymptotically evaluated as a function of the crack depth and time. The effect of a boundary layer associated with the diffusive term is identified. The theoretical model is supplied with numerical simulations. 相似文献
33.
New fabrication technologies now allow for hybrid sandwich structures, known as X-core, to be manufactured. The X-core panels
consist of a pin reinforced polymer foam core with carbon fiber face sheets. Carbon fiber or metallic (Titanium/Steel) pins
are inserted into the foam core in the out-of-plane direction and extend from face sheet to face sheet. The through thickness
three-point simply supported bending behavior of these panels is used to evaluate the collapse characteristics of the panels.
Explicit experimental observations are used to calibrate analytical energy balance models describing the panel collapse as
a function of geometry and properties. The mechanical response of X-core sandwich panels is compared to current sandwich materials
for material selection. 相似文献
34.
By repeatedly combining the source node’s nearest neighbor, we propose a node combination (NC) method to implement the Dijkstra’s algorithm. The NC algorithm finds the shortest paths with three simple iterative steps: find the nearest neighbor of the source node, combine that node with the source node, and modify the weights on edges that connect to the nearest neighbor. The NC algorithm is more comprehensible and convenient for programming as there is no need to maintain a set with the nodes’ distances. Experimental evaluations on various networks reveal that the NC algorithm is as efficient as Dijkstra’s algorithm. As the whole process of the NC algorithm can be implemented with vectors, we also show how to find the shortest paths on a weight matrix. 相似文献
35.
Tsuyoshi Miezaki 《Journal of Pure and Applied Algebra》2019,223(10):4153-4160
Eisenstein polynomials, which were defined by Oura, are analogues of the concept of an Eisenstein series. Oura conjectured that there exist some analogous properties between Eisenstein series and Eisenstein polynomials. In this paper, we provide new analogous properties of Eisenstein polynomials and zeta polynomials. These properties are finite analogies of certain properties of Eisenstein series. 相似文献
36.
指出文献 [2 ]和文献 [4]中的错误 ,并且得到含有单位圆盘内接解析函数与亚纯函数的几个不等式 . 相似文献
37.
本文研究了一类粗糙奇异积分算子的加权Triebel-Lizorkin有界性.对核函数Ω∈Llog L(Sn-1)建立了径向权函数的加权有界性;而对于核函数Ω∈Lr(Sn-1),1相似文献
38.
R. E. Hodel 《Topology and its Applications》1998,90(1-3):31-56
We use neighborhood assignments and cardinal functions to give a unified approach to metrizability and uniformity. This leads to a number of characterizations of m(X), the metrizability degree of X, u(X), the uniform weight of X, and w(X), the weight of X. For X normal (and regular), m(X) = u(X); it is unknown whether this result extends to completely regular spaces. 相似文献
39.
M.P. Estellita Lins A.C. Moreira da Silva C.A.K. Lovell 《European Journal of Operational Research》2007
The flexibility of weights assigned to inputs and outputs is a key aspect of DEA modeling. However, excessive weight variability and implausible weight values have led to the development of DEA models that incorporate weight restrictions, reflecting expert judgment. This in turn has created problems of infeasibility of the corresponding linear programs. We provide an existence theorem that establishes feasibility conditions for DEA multiplier programs with weight restrictions. We then propose a linear model that tests for feasibility and a nonlinear model that provides minimally acceptable adjustments to the original restrictions that render the program feasible. The analysis can be applied to restrictions on weight ratios, or to restrictions on virtual inputs or outputs. 相似文献
40.
赵新泉 《数学物理学报(A辑)》1998,18(1):63-69
该文在[1]的基础上,进一步探讨了区间[-1,1]上带Cauchy核奇异积分方程权函数的分解及其解的稳定性和在Chebyshev模下的稳定性条件.证明了扰动方程的可解性及原方程的解对于已知函数的连续依赖性. 相似文献