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141.
B. Klartag 《Geometric And Functional Analysis》2006,16(6):1274-1290
Let
be a convex body and ɛ > 0. We prove the existence of another convex body
, whose Banach–Mazur distance from K is bounded by 1 + ɛ, such that the isotropic constant of K’ is smaller than
, where c > 0 is a universal constant. As an application of our result, we present a slight improvement on the best general upper
bound for the isotropic constant, due to Bourgain.
The author is a Clay Research Fellow, and was also supported by NSF grant #DMS-0456590.
Received: November 2005; Accepted: February 2006 相似文献
142.
In this paper, we have introduced a Solid Transportation Problem where the constrains are mixed type. The model is developed under different environment like, crisp, fuzzy and intuitionistic fuzzy etc. Using the interval approximation method we defuzzify the fuzzy amount and for intuitionistic fuzzy set we use the ($\alpha,\beta$)-cut sets to get the corresponding crisp amount. To find the optimal transportation units a time and space based with order of convergence $O (MN^2)$ meta-heuristic Genetic Algorithm have been proposed. Also the equivalent crisp model so obtained are solved by using LINGO 13.0. The results obtained using GA treats as the best solution by comparing with LINGO results for this present study. The proposed models and techniques are finally illustrated by providing numerical examples. Degree of efficiency have been find out for both the algorithm. 相似文献
143.
安全性评价是提高企业安全管理水平的重要措施之一,结合平顶山煤业(集团)有限责任公司一矿的生产实际,建立了安全性评价指标体系.应用模糊数学理论,对胶带运输系统的安全性进行了模糊综合评判,指出了影响运输安全的主要因素中存在的问题,并提出了相应的改进措施. 相似文献
144.
In this paper, we present the first model of co-opetition for a Hub Location Problem between two logistics service provider (LSPs) companies where the mother company is the owner of infrastructure. The LSPs would like to cooperate with each other by establishing joint edges with limited capacities connecting their service networks. Such services are in form of pendulum services (a direct service between two points) between nodes of different networks. Additional market can be generated as a result of joining the two networks. At the same time, a competition is taking place between the two operators to increase their share from the additional market generated. In order to solve this problem, we propose a matheuristic approach combining a local search algorithm and a Lagrangian relaxation-based approach. In our matheuristic algorithm, the neighbourhood solutions are evaluated using a Lagrangian relaxation-based approach. Numerical results of applying the proposed algorithm on a real case study of the problem are presented. 相似文献
145.
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148.
优势面对矿区灾害事故发生展布具明显的控制作用。本文据诸多实例论述了地下开采中优势面的控水、控稳两类机制 ,并建立了相应的优势指标和评价准则 ,为地下开采灾害控制研究指出了一种新的思路和分析方法。 相似文献
149.
求解运输问题的一种算法 总被引:7,自引:1,他引:6
文章给出了运输问题的一种算法,该算法计算过程容易掌握,求解具有一次终止性 相似文献
150.
Matteo Milazzo Federico Musciotto Salvatore Miccich Rosario N. Mantegna 《Entropy (Basel, Switzerland)》2022,24(2)
We analyze structure and dynamics of flight networks of 50 airlines active in the European airspace in 2017. Our analysis shows that the concentration of the degree of nodes of different flight networks of airlines is markedly heterogeneous among airlines reflecting heterogeneity of the airline business models. We obtain an unsupervised classification of airlines by performing a hierarchical clustering that uses a correlation coefficient computed between the average occurrence profiles of 4-motifs of airline networks as similarity measure. The hierarchical tree is highly informative with respect to properties of the different airlines (for example, the number of main hubs, airline participation to intercontinental flights, regional coverage, nature of commercial, cargo, leisure or rental airline). The 4-motif patterns are therefore distinctive of each airline and reflect information about the main determinants of different airlines. This information is different from what can be found looking at the overlap of directed links. 相似文献