效用值为区间数的风险型决策问题分析

从敏感性分析的角度讨论后果效用值用区间数表示的风险型决策问题．基于区间数大小比较的可能度概念，定义了描述行动优劣的行动优性指标，并给出了该指标的若干性质；利用行动优性指标，提出了一种求解效用值用区间数表示的风险型决策问题的方法．针对这个简单直观的决策方法，重点分析了决策评价结果对主观概率变化的敏感性．具体针对当自然状态的主观概率发生变化时，分析了某个行动成为最优行动的可能性，并给出了保证该行动成为最优行动（如果可能的话）的主观概率的变化范围．最后，给出了一个实例进一步阐述了分析结果．     

三态叠加多模Schrdinger-cat态纠缠光场的不等幂次高次差压缩

引入了由多模复共轭相干态、多模复共轭虚相干态和多模真空态的线性叠加所组成的三态叠加多模Schr dinger-cat态纠缠光场,利用多模压缩态理论研究了这种光场的广义非线性不等幂次高次差压缩特性。结果发现:①真空场对此猫态光场的不等幂次高次差压缩效应没有影响;②在一定条件下,此猫态光场的两个正交相位分量可分别呈现出不等幂次高次差压缩效应;而在另外的条件下,此猫态光场的两个正交相位分量则可同时出现上述的不等幂次高次差压缩效应。     

基于失效情景的应急设施选址问题

非常规突发事件巨大的破坏力以及发生时间、地点和规模的不确定性,使应急系统内设施有可能被破坏而失效,因此选址时必须考虑设施失效情景的发生.给出以最大限度覆盖用户需求为目标,基于失效设施数目具有不确定性情景的设施选址双层随机规划模型;通过计算模型上下界,给出减小规模的等价模型,降低了双层规划求解难度;最后实验验证了模型的合理性,并给出新增选址方案.     

一种基于不确定度的证据冲突识别方法

从高度冲突证据对D-S证据理论的应用约束出发,针对几种常用冲突度量方法存在的问题,定义了描述证据自身特征的不确定度,将证据冲突涵义从证据间不一致扩展到证据内外,给出基于不确定度的证据冲突多元度量,并为增强冲突的识别效果提出最大差异度的冲突处理方法.验证分析得出:本文给出的度量方法能够有效表征证据间的冲突程度,最大冲突差异度的处理实现了证据冲突识别的显著化,在证据冲突度量与识别中具有很好的普适性和有效性.     

Radiation enhanced P-diffusion in germanium

Abstract

Cascade size may affect phase stability under irradiation because of two distinct contributions: the replacement to displacement cross-section ratio depends on the deposited energy density; ballistic jumps which tend to disorder ordered compounds occur by bursts, while thermal jumps which restore long range order occur one by one.

The latter effect cannot be handled by standard rate theory. A stochastic treatment of the problem, based on a Fokker Planck approximation of the relevant master equation is summarized. It is shown that the possible values of the long range order parameter under irradiation are not affected by the size of the cascade but that the respective stability of the former is cascade size sensitive. As a consequence, the stability diagram of phases under irradiation varies with the size of the cascades. A numerical example of this is given for the B2 structure.     

Third‐order sensitivity analysis for robust aerodynamic design using continuous adjoint

Robust design problems in aerodynamics are associated with the design variables, which control the shape of an aerodynamic body, and also with the so‐called environmental variables, which account for uncertainties. In this kind of problems, the set of design variables, which leads to optimal performance, taking into account possible variations in the environmental variables, is sought. One of the possible ways to solve this problem is by means of the second‐order second‐moment approach, which requires first‐order and second‐order derivatives of the objective function with respect to the environmental variables. Should the minimization problem be solved using a gradient‐based method, algorithms for the computation of up to third‐order sensitivity derivatives (twice with respect to the environmental variables and once with respect to the shape controlling design variables) must be devised. In this paper, a combination of the continuous adjoint variable method and direct differentiation to compute the third‐order sensitivities is proposed. This is shown to be the most efficient among all alternative methods provided that the environmental variables are much less than the design ones. Apart from presenting the method formulation, this paper focuses on the assessment of the so‐computed up‐to third‐order mixed derivatives through comparison with costly finite‐difference schemes. To this end, the robust design of a two‐dimensional duct is performed. Then, using the validated method, the robust design of a two‐dimensional cascade airfoil is demonstrated. Although both cases are handled as inverse design problems, the method can be extended to other objective functions or three‐dimensional problems in a straightforward manner. Copyright © 2012 John Wiley & Sons, Ltd.     

用板式电位差计实验系统和SPSS标定电池的内阻

针对板式电位差计测量电阻的实验装置,以干电池为研究对象,用补偿法测量实验数据,引入SPSS的曲线估计功能,得到并验证出长度和标准电阻的复合量与长度量的定标曲线,由此标定出待测干电池的内阻。用置信概率为95的不确定度,对实验结果进行分析和评价,最终得到更为直观的、可靠的实验结果。     

On safe tractable approximations of chance constraints

A natural way to handle optimization problem with data affected by stochastic uncertainty is to pass to a chance constrained version of the problem, where candidate solutions should satisfy the randomly perturbed constraints with probability at least 1 − ?. While being attractive from modeling viewpoint, chance constrained problems “as they are” are, in general, computationally intractable. In this survey paper, we overview several simulation-based and simulation-free computationally tractable approximations of chance constrained convex programs, primarily, those of chance constrained linear, conic quadratic and semidefinite programming.     

自复位学校建筑抗震韧性区域评估用数字孪生模型

在区域层面上对具有自复位模块结构的学校建筑进行抗震损伤和恢复力评估研究，建立了一个基于Python语言的从结构非线性分析到损伤程度可视化演示用的数字孪生模型。Python语言也是目前通用于机器学习模型训练的编程语言，方便在该数字孪生模型中引入人工智能模型来代替结构仿真计算，通过使用实时监测地震动和结构响应数据结合人工智能模型进行区域灾害响应和功能恢复快速评估。结构损伤和恢复力分析结果（如不同地震下修复成本、修复时间、不可修复的概率等指标）通过生成shapefile在地理信息系统（GIS）软件中进行三维可视化，从而对采用自复位模块结构的学校建筑结构群在区域范围上进行抗震韧性定量评估。该模型的计算模块包括区域建筑结构清单生成、简化数值模型建立、地震响应非线性分析、结构响应参数生成、建筑结构易损部件定义、地震损失概率模型评估以及区域灾害损失的结果输出。这里的基于概率模型的学校建筑结构地震损失评估采用了FEMA P-58方法，并使用了Pelicun软件包进行计算。以旧金山湾区近2 000栋学校建筑作为案例，对假定使用偏心支撑框架自复位结构作为抗震结构体系的学校建筑群进行了抗震韧性评估，研究了通...     

“证据推理与模型认知”素养下的主题式复习与反思*——以“二氧化碳的主题式复习”为例

以“草系水族箱内补给的气体”为主线,构建有关二氧化碳的主题式复习;在解决系列问题的过程中,重视围绕证据进行推理、基于模型进行认知,从而发展核心素养,提升复习效益。