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841.
842.
843.
Qinjiang Rao 《International Journal of Infrared and Millimeter Waves》1998,19(1):129-138
The method, connected with the concentric ring microstrip antenna and based on the perturbation , for the resonant wave numbers of eccentric ring microstrip antennas for all modes is suggested. The usefulness and accuracy of the method is shown through the comparison of the calculation used here with the measurement and other method from the reference. 相似文献
844.
Renu Laskar 《Discrete Applied Mathematics》2009,157(2):330-338
The question of whether a graph can be partitioned into k independent dominating sets, which is the same as having a fallk-colouring, is considered. For k=3, it is shown that a graph G can be partitioned into three independent dominating sets if and only if the cartesian product G□K2 can be partitioned into three independent dominating sets. The graph K2 can be replaced by any graph H such that there is a mapping f:Qn→H, where f is a type-II graph homomorphism.The cartesian product of two trees is considered, as well as the complexity of partitioning a bipartite graph into three independent dominating sets, which is shown to be NP-complete. For other values of k, iterated cartesian products are considered, leading to a result that shows for what values of k the hypercubes can be partitioned into k independent dominating sets. 相似文献
845.
We prove two results about the problem of finding the Helly number for line transversals to a family of parallel triangles in the plane: (1) If each three triangles of a family of parallel right triangles are intersected by an ascending (or a descending) line, then there is an ascending (or a descending) line that intersects all 相似文献
846.
不确定环境下服务资源配置优化 总被引:1,自引:0,他引:1
在服务资源配置过程中,按维修状态将服务对象分成三类:完全维修、部分维修及最小维修.由于维修服务的特性,服务成本与服务时间均是一个模糊数,并且维修对象在服务时所处的维修状态也具有一定的不确定性.针对这类情况下的服务资源配置问题,提出了同时考虑模糊服务成本和模糊服务时间及不确定维修状态的最小化服务成本为优化指标的服务资源配置模型.在模型的求解过程中采用多粒子群算法,通过仿真计算表明了该方法的可行性和有效性. 相似文献
847.
We propose to reduce the (spectral) condition number of a given linear system by adding a suitable diagonal matrix to the system matrix, in particular by shifting its spectrum. Iterative procedures are then adopted to recover the solution of the original system. The case of real symmetric positive definite matrices is considered in particular, and several numerical examples are given. This approach has some close relations with Riley's method and with Tikhonov regularization. Moreover, we identify approximately the aforementioned procedure with a true action of preconditioning. 相似文献
848.
Hydrodynamic properties and structure of strong shock waves in classical dense helium are simulated using non-equilibrium molecular dynamics methods. The shock speed in the simulation reaches 100 km/s and the Mach number is over 250, which are close to the parameters of shock waves in the implosion process of inertial confinement fusion. The simulations show that the high-Mach-number shock waves in dense media have notable differences from weak shock waves or those in dilute gases. These results will provide useful information on the implosion process, especially the structure of strong shock wave front, which remains an open question in hydrodynamic simulations. 相似文献
849.
This paper introduces genetic algorithms for the jump number scheduling problem. Given a set of tasks subject to precedence constraints, the problem is to construct a schedule to minimize the number of jumps. We show that genetic algorithms outperform the previously known Knuth and Szwarcfiter's exhaustive search algorithm when applied to some classes of orders in which no polynomial time algorithms exist in solving the jump number problem. Values for various parameters of genetic jump number algorithms are tested and results are discussed. 相似文献
850.
星和完全等二部图联图的点可区别均匀边染色 总被引:1,自引:0,他引:1
研究了星与完全等二部图的联图Sm∨Kn,n的点可区别均匀边染色。 相似文献