随机化均匀设计在股票交易上的应用

本文首先利用Bundschuh和朱尧辰(1993)的偏差精确计算公式,给出了某些二维均匀设计的生成元.其次,利用随机化均匀设计提出了一种可以提高以移动平均线进行股票交易的赚钱概率的方法.     

洪水演算中时段平均流量计算的曲线积分法

用曲线积分代替算术平均法来计算洪水流量演算中的时段平均流量,减少了时段Δt对流量值的影响,使计算流量更接近实测值。     

Means and their applications

General considerations about means and expectations are preceded by a short historical overview. The existing approaches to the definition of means are classified into three groups: approximational, functional, and axiomatic. In some particular cases all of them are equivalent. The problem of meaningfulness of means is discussed for ordinal data and for some important cases of metric data. A survey of the main areas of applications: decision theory, group decision, insurance, economical equity and inequality is also provided. This revised version was published online in June 2006 with corrections to the Cover Date.     

用积分平均方法求解压电圆柱壳内波的轴向传播

对压电圆柱壳体内波的轴向传播进行了研究。应用积分平均方法得到了一组位移和电势耦合的拟二维动力学方程,并且求解了这组方程。发现当波沿着圆柱壳体轴向传播时,物质的径向运动、轴向运动和电势的变化相互耦合,伴有频散现象;但是扭转运动可以独立表示,并且同电场无关,无频散现象。在得到频散关系的基础上,通过数值计算模拟出压电圆柱壳体在受到端部轴向应力脉冲激励后壳体内的轴向应力和电势分布图。还讨论了压电圆柱壳体半径比对波传播的影响。     

试论商誉对报业企业利润最大化的影响——以上海报业企业为例

新经济时代,利润最大化更是企业经营的永恒目标。通过分析影响报业企业商誉的各种因素,结合实例验证,探讨商誉对报业企业利润最大化的影响,旨在为报业企业达到利润最大化提供一定的方法指导。     

查找算法平均查找长度的计算方法

给出了常用查找算法平均查找长度的计算方法,包括查找成功和查找失败平均查找长度的计算,并通过实例进行了解析,便于学习者学习和掌握查找算法,同时为应用者选择查找算法提供依据。     

The collision frequency of electron-neutral-particle in the weakly ionized plasma with the power-law velocity distribution

We study the collision frequency of electron-neutral-particle in the weakly ionized plasma with the power-law velocity q-distribution and derive the formulation of the average collision frequency. We find that the average collision frequency in the q-distributed plasma also depends strongly on the q-parameter and thus is generally different from that in the Maxwell-distributed plasma, which therefore modifies the transport coefficients in the previous studies of the weakly ionized plasmas with the power-law velocity distributions.     

多服务台同步工作休假的Geom/Geom/c排队

在多服务台离散时间排队的基础上,研究了服务台同步工作休假模型.利用矩阵几何解的方法,详细给出了过程满足正常返性的条件和率阵存在性的证明,从而得到稳态分布和平均队长的表达式.设置好参数,利用MATLAB编程,得到了数值例子,进一步证实了系统理论分析的正确性,并得到了平均队长与几个重要参数之间的关系图像.     

结合内时理论研究岩石衰减与应变振幅的关系

本文将解决复杂弹塑性问题的有效工具内时理论,引入到岩石衰减的研究中来。根据内时理论,简要推导了在中等应变条件下,岩石衰减与应变振幅的用非弹性参数α表示的具体关系式。在MTS压机上,对砂岩、花岗岩等多种岩石样品进行了一系列的循环加卸载实验。利用应力应变滞回曲线的面积,根据衰减的能量损耗的定义,计算了各种实验条件下的岩石样品的衰减值。实验数据表明,在各次循环平均应力相等的条件下,岩石样品的衰减随应变振幅的增加而增加,与内时理论的推导结果相一致。最后,对表示岩石非弹性的参数α进行了简要的讨论。砂岩的α值较为稳定,在0.5左右;而花岗岩的α值变化较大,但二者都随着应力的增加而增加。该实验结果对地震波在地球介质中的衰减研究有一定的参考意义。     

Practical Method for Analysis of Immiscible Displacement in Laboratory Core Tests

Abstract. An accurate analytical interpretation method to determine the Leverett function (f_w)and its derivative (f_w) from immiscible displacement data in core plugs is presented. Linear equations are developed to describe the displacement processes occurring before and after breakthrough. A quadratic function is introduced to represent the saturation distribution along the cores. The relationships derived in this study can be used for analysis of core tests involving constant injection rates and constant pressure differences. The applicability, practicality, and accuracy of the new analytical method are verified by means of the experimental data obtained in the present study and by those reported in the literature.