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951.
Consider a single-server queue with a Poisson arrival process and exponential processing times in which each customer independently reneges after an exponentially distributed amount of time. We establish that this system can be approximated by either a reflected Ornstein–Uhlenbeck process or a reflected affine diffusion when the arrival rate exceeds or is close to the processing rate and the reneging rate is close to 0. We further compare the quality of the steady-state distribution approximations suggested by each diffusion. 相似文献
952.
V. V. Gorskii 《Computational Mathematics and Mathematical Physics》2007,47(6):895-899
A system of relations is presented for determining optimal coefficients for a set consisting of an arbitrary number of smoothly matched cubic polynomial dependences. As an example, the method is used to construct optimal approximating formulas for the viscosity of air in thermochemical equilibrium as a function of enthalpy. 相似文献
953.
954.
利用能量为2.0GeV的136Xe和2.7GeV的238U离子对C60薄膜进行了辐照,并用傅立叶变换红外光谱、X射线衍射谱和拉曼散射技术分析了辐照过的C60样品,在傅立叶变换红外光谱上,首次观察到一个位于670cm-1处的,表征未知结构的新峰,研究了其强度随电子能损和辐照剂量的变化规律.分析结果表明,电子能量转移主导了C60薄膜的损伤过程;而损伤的部分恢复是由强电子激发的退火效应引起的;另外,离子的速度在损伤的建立过程中也起了一定的作用 相似文献
955.
We present a new approach that permits efficient performance analysis of kanban systems with general demand processes, material
arrival processes, and service times. The approach is based on parametric characterization of the traffic processes (arrival
and departure) in the network and uses two-moment approximations to estimate performance measures at individual stations.
We derive traffic flow constraints that are particular to closed queuing networks with synchronization stations and use these
to establish relationships between the parameters characterizing arrival and departure processes at the stations in the network.
The resultant set of non-linear equations is solved to estimate network performance measures. Numerical studies show that
the approach is not only fast but also reasonably accurate when compared to simulation. These studies also provide insights
with respect to the impact of different types of variability on the performance of a kanban system. This work also provides
a fundamental building block that can be used in the analysis of multi-stage kanban systems.
AMS Subject Classifications 68M20, 60K20, 90B05, 90B30 相似文献
956.
{X_n,n≥1)是标准高斯序列,T_(ij)=cov(X_i,X_j)。本文在强相依条件rijlog(j-i)→r∈(0,∞)(j-i→ ∞)下,得到了高斯序列的最大值M_n与标准化部分和S_n=sum from i=1 to n(X_i/(E(sum from i=1 to n X_i)~2)/(1/2)) 相似文献
957.
958.
V. S. Kulhar 《Pramana》2004,63(3):543-551
The muonium/muonic hydrogen atom formation in μ±−H collisions is investigated, using a two-state approximation in a time dependent formalism. It is found that muonium cross-section
results are similar to the cross-section results obtained for positronium formation in e+-H collision. Muonic hydrogen atom formation cross-sections in μ--H collision are found to be significant in a narrow range of energy (5 eV–25 eV). 相似文献
959.
Nonlinearity effects in multidimensional scaling 总被引:1,自引:0,他引:1
When multidimensional scaling of n cases is derived from dissimilarities that are functions of p basic continuous variables, the question arises of how to relate the values of the variables to the configuration of n points. We provide a methodology based on nonlinear biplots that expresses nonlinearity in two ways: (i) each variable is represented by a nonlinear trajectory and (ii) each trajectory is calibrated by an irregular scale. Methods for computing, calibrating and interpreting these trajectories are given and exemplified. Not only are the tools of immediate practical utility but the methodology established assists in a critical appraisal of the consequences of using nonlinear measures in a variety of multidimensional scaling methods. 相似文献
960.
主要研究了B-值双随机Dirichlet级数在不同条件(i){Xn}服从强大数定律,且 (ii){Xn}独立不同分布,且 等条件下的收敛性,得出了收敛横坐标的简洁公式. 相似文献