两类加工时间是一般函数的单机排序问题

考虑了两类有一般加工时间函数的排序问题. 工件的加工时间分别为基本加工时间与开工时间函数、位置函数的和. 对加工时间依赖开工时间的模型,证明了一定条件下极小化最大完工时间和极小化总完工时间是多项式可解的. 对加工时间依赖开工位置的模型,给出极小化最大完工时间和极小化总完工时间的最优序,同时证明了极小化加权总完工时间的一个最优排序性质并给出一个贪婪算法.     

磨削加工具有复杂母线的旋转体的微分模型

综合运用微分几何、坐标变换、分段二次Hermite插值及微分方程等数学工具,将磨削加工具有复杂母线的旋转体的问题,通过建立微分模型,然后根据求出的解,设计出了具体的加工方案.对于具有抛物线母线的工件,给出了一个在上台电机进给速度恒定的条件下,加工时间尽可能短的加工方案.对于具有一般母线的工件,利用分段二次Hermite插值,转化为抛物线的情形,也得到了很好的解决.还编写了一系列Matlab程序,作为解决过程中的产品,它们的输出可以直接用于控制磨床,加工具有任意母线的工件.此外,在使得砂轮表面的磨损尽量均匀的问题上,做了富有创造性的探索,并且给出了一个使得圆柱形砂轮磨损比较均匀的加工方案.总体而言,模型具有适用范围广、加工精度高等优点.     

具有学习效应和加工时间可控的平行机排序问题

本文研究了一类不相关平行机的排序问题,在该问题中工件的加工时间既具有学习效应,又资源可控,也就是说在该问题模型中,工件的实际加工时间为其正常的加工时间、加工过程中工件所处位置以及加工时间可控这些变量的函数。该研究的目的是为使得总机器负载和总的控制费用的加权和最小以及总的完工时间和总的控制费用的加权和最小。文章通过对问题的相关性质的分析和证明找到了一个解决问题的最优化算法,并且也证明了在处理机的数量给定的条件下,该问题的时间复杂性为O(n^m+2),最后也给出了相应的数值例子来阐述该问题。     

一台机器在加工时间相同准备时间可控时的Lmax问题

一组ｎ个工件需在一台机器上加工，工件ｊ所需的加工时间，应交工时间、准备时间分别为ｐｊ、ｄｊ、ｒｊ＾０，准备时间可压缩量为ｘｊ，０≤ａｊ≤ｒｊ＾０，压缩权因子为ωｊ由最大延误Ｊｍａｘ和压缩费用∑ωｊｘｊ可构成文中（Ｐ１）－（Ｐ３）三个排序问题，在ｄｊ＝０的条件下，引文「１」的作者证明了（Ｐ１）、（Ｐ３）为强ＮＰ－Ｃ的。本文在ｄｊ任意，ｐｊ＝ωｊ＝１的条件下，对（ｐ１）－（Ｐ３）给出了一个伪多项式时间     

用矩阵的方法来研究工件加工时间

通过构造特殊矩阵给出既定加工次序下加工零件所需时间表达式.     

面向钢铁混合加工作业的资源分配方法研究

面向订单生产的钢铁企业实际生产过程中,在订单量、设备生产能力不匹配的约束条件下,加热、退火等工序会出现混合加工情况,如何合理计算混合加工时产品的资源消耗量是提高产品成本准确性的关键.本文提出了基于粗糙集和BP神经网络相结合的混合加工资源消耗计算方法,通过粗糙集提取了资源消耗的必要影响因素,确保资源分配对象划分准确,利用BP神经网络建立影响因素与资源消耗的分配关系,通过上述关系计算混合加工时的资源消耗量.最后通过实例,应用5-fold交叉验证方法,提高了资源分配模型的泛化能力,并与回归分析法对比,验证了该方法具有较高的精度和收敛速度,为混合加工作业在成本动因很难制定情况下,准确计算资源消耗提供了方法支持.     

一个非常规目标函数的单机随机调度的最优策略

本文考虑了n个工件在同一台机器上加工的调度问题 ,其中工件的加工时间和交货期都是具有任意分布的随机变量 .我们考虑了一个非常规目标函数 ,其中工件的权数与平均加工时间成比例 .在工件的交货期与加工时间满足相容条件下 ,得到了个简单的最优排序策略 .     

数控加工刀具运动的优化控制

数控加工的精准性与高速性主要体现在加工路径的插补与加工过程中刀具的速度控制.首先针对数控加工过程中常见的折线轨迹进行分析,提出了折线加工转角处的速度平滑过渡方案,保证加工精度的同时提高加工效率.进一步,得出了转角处的最大加工速度与加工误差关系.针对圆弧类曲线插补问题,在折线模型的基础上拓展了内接和外切两种插补方案.计算结果表明,采用折线平滑过渡时,外切插补方案可以保证更高的精度.     

供应链管理中加工/外包决策问题的模型

供应链管理中的一个核心问题是零部件的加工/外包决策。本在献[1]的两部门一种原材料，一种零部件的产量优化模型的基础上，提出了两部分和三部分多种原材料、多种零部件的产量优化模型，并在此基础上发展了企业的加工/外包决策模型。本的结果可为供应链管理中加工/外包决策问题提供科学的依据。     

含有批处理机的三机流水作业加工总长问题的计算复杂性

研究含有批处理机的三台机器流水作业加工总长问题的计算复杂性.不仅考虑了批处理机容量有限的情形,还考虑了批处理机容量无限的情形.证明了当第二台机器是批处理机、其余两台机器是单机时,该问题是NP困难的.至此,含有批处理机的三台机器流水作业加工总长问题在所有情形下的计算复杂性得到了解决.     

The Hill estimators under power normalization

By using the link between the affine and the power norming, eight Hill estimators under power normalization for the tail index (the non-zero extreme value index) are suggested. Moreover, more compact and adaptive four Hill estimators under power normalization are derived based on the generalized Pareto distributions under power normalization. Two classes of harmonic t-Hill estimators under power normalization are also suggested. A comprehensive simulation study using the R-package shows that all the suggested estimators under power normalization work well, but in all cases the Hill estimators under power normalization based on Pareto distributions under power normalization are better. The two models under linear and power normalization for extreme value analysis are applied with comparison on a real data set of two pollutants, Sulphur Dioxide and Particulate Matter.     

Magnetically created instability in a collisionless plasma

In the Vlasov–Maxwell theory we prove that there are homogeneous equilibria that are monotone decreasing in every direction and are arbitrarily close to a Maxwellian. They are unstable under certain electromagnetic perturbations, but are stable under purely electric perturbations as well as under electromagnetic perturbations of sufficiently short period. These statements are valid both in the linear and nonlinear senses.     

Log-logistic parameters estimation using moving extremes ranked set sampling design

In statistical parameter estimation problems, how well the parameters are estimated largely depends on the sampling design used. In the current paper, a modification of ranked set sampling(RSS) called moving extremes RSS(MERSS) is considered for the estimation of the scale and shape parameters for the log-logistic distribution. Several traditional estimators and ad hoc estimators will be studied under MERSS. The estimators under MERSS are compared to the corresponding ones under SRS. The simulation results show that the estimators under MERSS are significantly more efficient than the ones under SRS.     

优良抽样设计下Logistic分布中参数的极大似然估计

当研究目标的实际测量具有不可修复的破坏性或耗资巨大时,有效的抽样设计将是一项重要的研究课题.在统计推断方面,排序集抽样(RSS)被视为一种比简单随机抽样(SRS)更为有效的收集数据的方式.动态极值RSS (MERSS)是一种修正的RSS.文章在SRS和MERSS下研究了Logistic分布中参数的极大似然估计(MLEs).在这两种抽样下证明了该分布中位置参数和刻度参数的MLEs的存在性和唯一性,并计算了所含参数的Fisher信息量和Fisher信息矩阵.比较了这两种抽样下对应估计的渐近效率.数值结果表明MERSS下的MLEs一致优于SRS下的MLEs.     

An analysis of voluntary recycled content claims under demand benefit and uncertain recycled input supply

We focus on the problem of choosing the optimal recycled content claim under stochastic local recycled content availability under two claim types — period specific (when claims have to hold each period) and average (when claims are evaluated across periods). We show conditions under which specific claims are higher than average claims, and explore cases where the optimal claims and profits are aligned to be in the same direction.     

On the perturbation of semi-Fredholm relations with complemented ranges and null spaces

Multivalued semi-Fredholm type linear operators with complemented ranges and null spaces are introduced. Conditions are obtained under which the classes given are stable under compact, strictly singular and strictly cosingular additive perturbations.     

Commitment for storable good duopoly

Commitment plays exceedingly important roles in industrial organization theory and there exists extensive research on the commitment. In this paper, we extend commitment for storable goods to duopoly structure. Based on the discrete-time dynamic models, commitment is compared with non-commitment under duopoly and the corresponding results are obtained. Namely, the prices under commitment are lower than that without commitment under duopoly and the social welfare is improved under commitment.     

Sample rotation theory with missing data

This paper studies how the sample rotation method is applied to the case where item non-response occurs in surveys. The two cases where the response to the first occasion is complete or incomplete are considered. Using ratio imputation method, the estimators of the current population mean are proposed, which are valid under uniform response regardless of the model and under the ratio model regardless of the response mechanism. Under uniform response, the variances of the proposed estimators are derived. Interestingly, although their expressions are similar, the estimator for the case of incomplete response on the first occasion can have smaller variance than the one for the case of complete response on the first occasion under uniform response. The linearized jackknife variance estimators are also given. These variance estimators prove to be approximately design-unbiased under uniform response. It should be noted that similar property on variance estimators has not been discussed in literature.     

多目标半定规划的互补弱鞍点和G-鞍点最优性条件

对于含矩阵函数半定约束和多个目标函数的多目标半定规划问题，给出Lagrange函数在弱有效意义下的互补弱鞍点和Geofrrion恰当有效意义下的G-鞍点的定义及其等价定义．然后，在较弱的凸性条件下，利用含矩阵和向量约束的择一性定理，建立多目标半定规划的互补弱鞍点和G-鞍点充分必要条件．     

哈明距离下的网络逆问题研究综述

逆优化问题研究的是如何改变原问题中的权参数,使得某些给定的解是问题在新的权参数下的最优解,且使总的改造费用尽可能少.作为逆优化问题中相对较新的一个分支,哈明距离下的网络逆问题具有较大的理论研究及实际应用价值.此文首先介绍了逆优化问题和哈明距离下的网络逆问题以及它们的应用,然后详细介绍了哈明距离下的网络逆问题的研究动态及使用的研究方法.最后给出了该领域中的一些值得研究的问题.