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121.
Michell’s problem of optimizing truss topology for stress or compliance constraints under a single load condition is solved
analytically for plane trusses having a square-shaped line support. Geometrical characteristics of the Hencky nets giving
the truss layout are expressed in terms of Lommel functions. Analytically derived truss volumes for the above problem are
compared with those of trusses supported along circles of equivalent area. Some general implications of the results are also
discussed. 相似文献
122.
Comments on the effect of yttrium on the early stages of oxidation of alumina formers 总被引:3,自引:0,他引:3
Jerzy Jedliński 《Oxidation of Metals》1993,39(1-2):55-60
123.
The precipitation process in alloys containing 4% Ti and 5 to 16% Ni was investigated using transmission electron microscopy, hardness and electrical conductivity measurements. After ageing, spherical -Ni3Ti precipitates with ordered DO22 superlattice were observed in alloys CuTiNi5 to 10 and the L12 superlattice in the CuTi4Ni16 alloy. With increasing nickel content the size of precipitates decreases; this has only a minor influence on the age hardening. The CuTiNi10 alloy has the best electrical conductivity approaching 18m–1mm–2. 相似文献
124.
Micha Klein 《国际水》2013,38(4):244-248
Sharing water in the Jordan basin has been a key topic in the recent peace talks between Israel and its neighbors. Knowing the quantity of water available is a prerequisite to water sharing. Many different values have been published in recent years. Different sources report Jordan's discharge flow into Lake Kinneret anywhere from 460 to 800 Mm3/year. The aim of this article is to present a water balance for the Jordan basin for a 15-year period. The years 1977–1978 to 1991–1992 were studied for the basin's water budget, as they represent the present day (1998) land use. The results show that Lake Kinneret has a yearly average input (= output) of 770 Mm3. Israel uses some 800 Mcm3/year from the entire Jordan basin, of which 440 Mm3 is used within the basin and the rest outside. There is about 100 Mm3 for future utilization in the watershed. The yearly Jordan's discharge to the Dead Sea is 220–250 Mm3. Reporting by various secondary data sources is compared to primary data findings to illustrate the great variability of data reporting and to provide annual flow estimates, based largely on primary sources, for the Upper Jordan River. 相似文献
125.
This paper considers methods for knowledge exploitation in security policies for Service-Oriented Architecture (SOA) environments, discovering the modality conflicts in particular. Two algorithms for discovering SOA-specific modality conflicts are proposed. First, a trivial (ad-hoc) approach is presented and further extended by the improved algorithm which offers lower time complexity. The formal verification of the proposal is followed by experimental results confirming the expected supremacy of the improved algorithm. 相似文献
126.
Edyta Szymańska 《Information Processing Letters》2012,112(23):899-902
127.
The Parity Path problem is to decide if a given graph contains both an induced path of odd length and an induced path of even length between two specified vertices. In the related problems Odd Induced Path and Even Induced Path, the goal is to determine whether an induced path of odd, respectively even, length between two specified vertices exists. Although all three problems are NP-complete in general, we show that they can be solved in $\mathcal{O}(n^{5})$ time for the class of claw-free graphs. Two vertices s and t form an even pair in G if every induced path from s to t in G has even length. Our results imply that the problem of deciding if two specified vertices of a claw-free graph form an even pair, as well as the problem of deciding if a given claw-free graph has an even pair, can be solved in $\mathcal{O}(n^{5})$ time and $\mathcal{O}(n^{7})$ time, respectively. We also show that we can decide in $\mathcal{O}(n^{7})$ time whether a claw-free graph has an induced cycle of given parity through a specified vertex. Finally, we show that a shortest induced path of given parity between two specified vertices of a claw-free perfect graph can be found in $\mathcal {O}(n^{7})$ time. 相似文献
128.
129.
Iron-ruthenium catalysts prepared by impregnation of calcination products of -, , -and -iron oxide-hydroxides with either ruthenium chloride or ruthenium red were tested for the activity for the water-gas shift reaction. The effect of support, ruthenium containing impregnation agent and thermal treatment on catalyst performance was discussed. 相似文献
130.
Quattor: Tools and Techniques for the Configuration,Installation and Management of Large-Scale Grid Computing Fabrics 总被引:1,自引:0,他引:1
R. García Leiva M. Barroso López G. Cancio Meliá B. Chardi Marco L. Cons P. Poznański A. Washbrook E. Ferro A. Holt 《Journal of Grid Computing》2004,2(4):313-322
This paper describes the quattor tool suite, a new system for the installation, configuration, and management of operating systems and application software for computing fabrics. At present Unix derivatives such as Linux and Solaris are supported. Quattor is a powerful, portable and modular open source solution that has been shown to scale to thousands of computing nodes and offers a significant reduction in management costs for large computing fabrics. The quattor tool suite includes innovations compared to existing solutions which make it very useful for computing fabrics integrated into grid environments. Evaluations of the tool suite in current large scale computing environments are presented. 相似文献