基于风险-均值分析的供应商选择与订单分配集成优化模型与求解

针对不确定环境下具有不同供应合约的供应商选择与订单分配问题,本文构建了基于风险-均值分析的模糊两阶段多周期集成优化模型。与传统的该问题研究并未充分考虑供应商选择与订单分配两阶段决策的交互影响不同,在该模型中,第一阶段供应商选择的评价目标依赖于后期实际运营中的订单分配决策;并考虑未来需求和实际运营成本的不确定性,引入在险价值和期望值两种决策准则对供应商选择方案的绩效进行评价。提出了该模型的分析求解方法,在险价值得以精确评估,期望值被控制在确定的误差范围内,并可以达到足够的精度要求。     

多周期多产品采购量分配优化模型

为了解决随机需求与价格折扣并存条件下的多周期多产品采购量分配问题,建立了相应的多目标混合整数随机规划模型.该模型的特点是:①模型的约束条件中兼具确定性和随机性;②通过累计需求和累计采购量表示多周期的库存持有成本;③通过约束条件方程式准确地表现随机需求和价格折扣两大假设条件.针对该模型的特殊结构,提出了一种适用的求解策略:首先,通过把机会约束转化为确定性等价类,从而将多目标混合整数随机规划模型转化为确定型多目标混合整数规划模型;然后,采用目标规划法求得问题的满意解.此外,通过应用算例说明了模型的有效性和可行性.     

A new modified remote user authentication scheme using smart cards

In 2000, a remote user authentication scheme using smart cards was proposed and the masquerade attacks were proved successful on this scheme. Recently, Kumar has suggested the idea of check digits to overcome the above attacks with a new scheme that removes these threats well. In this paper it is pointed out that the weakness still exists in Kumar＇s scheme, and the intruder can login to the remote system through having some information. A new scheme which can overcome these attacks and appears more secure and efficient than Kumar＇s is presented.     

冲击型微小三通内弹环状流的相分配特性

本文在入口条件为弹环状流的条件下,考察了氮气-水两相流在水力直径为0.5 mm的水平等径冲击型三通中的相分配特性。根据入口与两个分支夹角的不同,冲击型三通分为T型冲击三通和Y型冲击三通。结果发现:相分配受入口流型的影响因冲击角而异。对于T型三通,入口流型对相分配的影响较小;而对于Y型三通,随着入口条件从靠近弹状流区域过渡到靠近环状流区域,相分配往等干度分配线靠近。变动冲击角对气液两相流的相分配有一定的影响,影响程度因入口条件而异。     

AN EFFICIENT SEQUENTIAL DESIGN FOR SENSITIVITY EXPERIMENTS

In sensitivity experiments, the response is binary and each experimental unit has a critical stimulus level that cannot be observed directly. It is often of interest to estimate extreme quantiles of the distribution of these critical stimulus levels over the tested products. For this purpose a new sequential scheme is proposed with some commonly used models. By using the bootstrap repeated-sampling principle, reasonable prior distributions based on a historic data set are specified. Then, a Bayesian strategy for the sequential procedure is provided and the estimator is given. Further, a high order approximation for such an estimator is explored and its consistency is proven. A simulation study shows that the proposed method gives superior performances over the existing methods.     

LG研发出成本更低的大尺寸柔性屏幕

正根据国外媒体报道,一直以来在柔性屏幕方面颇有建树的LG最近研发出了新工艺及材料,可以大幅降低柔性屏幕的生产成本。根据LG Display的研究人员表示,新工艺可以让柔性屏幕直接卷成一个曲面,并且通过对工艺和材料的创新,未来这种屏幕的造价会变得更低。在韩国全州举办的2014国际柔性与可打印电子研讨会上,LG Display研发中心的一名研究员Kim Kyung-min表示,该公司计划使用铜材料和"roll-toroll"技术,以便降低在制造柔性显示面板时的成本。采用这种"印刷"方法生产出来的面板,需要经过"roll两次"的过程。     

Circular threshold quantum secret sharing

This paper proposes a circular threshold quantum secret sharing （TQSS） scheme with polarized single photons. A polarized single photon sequence runs circularly among any t or more of n parties and any t or more of n parties can reconstruct the secret key when they collaborate. It shows that entanglement is not necessary for quantum secret sharing. Moreover, the theoretic efficiency is improved to approach 100% as the single photons carrying the secret key are deterministically forwarded among any t or more of n parties, and each photon can carry one bit of information without quantum storage. This protocol is feasible with current technology.     

一阶时滞微分方程解的零点分布

Abstract. The paper gives two estimates of the distance between adjacent zeros of solutions     

贷款分配方法的数学模型及其解法

为了解决三角债问题，银行给出一笔贷款，应该如何分配这笔贷款，使清理的债务达到最大。本文建立这个问题的数学模型，并且给出一个解法。     

一种稳定的自由空间量子密钥分配实验系统

基于量子密钥分配的基本原理,采用B92方案,以单光子作为信息载体,使用极化编码,搭建了一个简单易行的实验装置,实现了自由空间传输的量子密钥分配,平均每脉冲光子数为0．1,粗码率12．7kbits／s,误码率4％左右。