内P-反动态信息特征与信息恢复

P-集合(packet sets)是一个动态模型,P-集合是由内P-集合x~F(internal packet set X~F)与外P-集合XF(~Fouter packet set X~F)构成的元素集合对;或者(X~F,X~F)是P-集合.利用内P-集合的结构,给出内P-信息,内P-反动态信息,信息的内P-反动态恢复概念,给出内P-反动态信息的属性合取收缩生成,给出内P-反动态信息与内P-信息同属性定理,给出内P-反动态信息存在与属性合取范式定理,给出信息的内P-反动态恢复属性定理.这些基本理论结果是把内P-集合与一类信息系统故障状态识别交叉,渗透研究得到的.     

外P-反动态信息特征与信息恢复

利用P-集合的结构与动态特性,给出外P-信息,外P-反动态信息,外P-反动态信息生成与外P-反动态信息恢复概念;外P-反动态信息是.P-集合的新特征.利用这些新概念,给出一些新的理论结果:外P-反动态信息属性定理,外P-反动态信息属性合取定理,外P-反动态信息恢复定理与外P-反动态信息单位圆定理.     

基于可拓集合的动态分类及其UML表示方法研究

可拓集合是分析事物的可变性和多变性的理论基础 .本文首先建立了物元与类之间的联系 ,在可拓集合零界的基础上建立了过渡类 ,为了形式化描述出多值分类 ,对关联函数进行约束 ,并利用可拓域与物元变换探讨了动态分类机制 ,最后采用 UML构造型扩展机制对动态分类的表示问题进行初步的研究 .     

动态投资组合现金次可加风险度量的时间相容性

本文把Burgert和Rüschendorf (2006)及Rüschendorf(2013)的静态投资组合凸风险度量的研究框架推广到动态现金次可加情形中进行研究.利用风险度量公理化方法建立了条件投资组合现金次可加风险度量的研究框架,给出相应的表示定理,并研究了动态投资组合现金次可加风险度量在满足假定条件下的时间相容性问题,推广了Burgert和Rüschendorf(2006)及EL Karoui和Ravanelli(2009)的结论.     

外P-反动态信息特征与信息恢复北大核心

利用P-集合的结构与动态特性,给出外P-信息,外P-反动态信息,外P-反动态信息生成与外P-反动态信息恢复概念;外P-反动态信息是.P-集合的新特征.利用这些新概念,给出一些新的理论结果:外P-反动态信息属性定理,外P-反动态信息属性合取定理,外P-反动态信息恢复定理与外P-反动态信息单位圆定理.     

动态最小费用路在L1模下的逆问题讨论

考察动态最小费用路在L_1模下的逆问题,其中在弧费用的定义中,将弧(i,j)上的运行时间d_(ij)(t)分成最小可能运行时间d_(ij)~*和超出的运行时间(excess time)e_(ij)(t)两部分,弧(i,j)上费用即为两者赋权之和.在逆问题的讨论中考虑先将动态网络中的问题通过时间扩张网络G~T转化为静态问题,然后再利用解线性规划的逆问题的方法来解该动态最短路问题的逆问题.     

替代产品的动态库存决策与控制

考虑了替代产品的动态库存决策与控制问题,建立了替代产品的多周期动态库存决策与控制模型.得到了目标函数的一些重要性质,给出了系统最优参数的求解算法,利用动态规划方法对系统的库存参数进行了优化求解.     

基于模糊层次分析法的动态群决策及其应用

探讨了基于常规AHP的模糊动态层次分析法(FDAHP)的实现过程,对其判断矩阵的一致性问题进行了深入研究。针对传统静态群决策不能反映决策对象的动态变化的不足,提出了基于FDAHP的动态群决策算法,并将其应用于舰船各费用成份的动态分析中,取得了良好效果。     

二层次消费与投资决策优化动态规划模型

在动态多阶段情形,投资者面临的环境不仅只有投资环境,还包括消费环境.投资者关于投资与消费的决策具有层次性.因为消费事关人的生存需要,是优先要考虑的问题,且投资的最终目的还是为了消费,所以使消费最大化应是高一层次的目标,而使投资最大化则应是次一级的目标.因此,试图建立一个二层次消费与投资决策优化动态规划模型,以便更好地模拟现实世界的情况.讨论了该模型的动态决策过程和最优解的性质.     

多重嵌套的可计算非线性动态投入产出模型及其平衡增长解

给出多重嵌套的可计算非线性动态投入产出模型,并给出相应的价格、利润率、产出结构、增长率的平衡增长解计算公式.从本文给出的模型可以看出非线性投入产出模型可以有无穷多种不同形式,其中只有1种为众所周知的列昂惕夫线性投入产出模型.本文模型的重要意义在于它是线性投入产出模型与CGE（可计算一般均衡）模型的统一.它既克服了线性投入产出模型资本与劳动不可替代的缺点,又可方便地求解动态CGE的平衡增长解.     

预设尺度滤波器的双正交小波矩阵的构造

本文研究尺度滤波器的基本分解问题。基于所得结果，对于任意给定的尺度滤波器，给出了双正交小波矩阵的构造方案。     

Dynamic hashing

A new file organisation called dynamic hashing is presented. The organisation is based on normal hashing, but the allocated storage space can easily be increased and decreased without reorganising the file, according to the number of records actually stored in the file. The expected storage utilisation is analysed and is shown to be approximately 69% all the time. Algorithms for inserting and deleting a record are presented and analysed. Retrieval of a record is fast, requiring only one access to secondary storage. There are no overflow records. The proposed scheme necessitates maintenance of a relatively small index structured as a forest of binary trees or slightly modified binary tries. The expected size of the index is analysed and a compact representation of the index is suggested.     

双层规划问题的一种模式搜索Filter方法

双层规划在工程设计和经济管理中应用广泛,结合模式搜索方法和Filter方法提出了一种解决双层规划问题的算法—模式搜索Filter方法.算法以Filter法思想构造接受准则,以模式搜索提供迭代方向和步长,能够有效的解决一类双层规划问题.     

动态规划的单增量搜索算法

本文首先对现有的三种动态规划迭代算法：微分动态规划、渐进优化算法、状态增量动态规划作了简单评述。针对如何进一步减少计算工作量和加快收敛速度，提出单增量搜索算法。通过理论阐述和实例分析，说明这种新的迭代算法优于上述三种常用方法。最后，本文把这种方法推广到连续型动态规划问题。     

Learning in Dynamic Decision Making: The Recognition Process

The apparent difficulty that humans experience when asked to manage dynamic complexity might be related to their inability to discriminate among familiar classes of objects (i.e., flawed recognition). In this study we examined the change in individuals' recognition ability, as measured by the change in the similarity of decisions they made when confronted repeatedly with consistent dynamic situations of varying degrees of similarity. The study generated two primary findings. First, decisions became increasingly similar with task practice, a result that suggests gradually improving discrimination by the participants. Second, the similarity was determined by the interaction of many task features rather than individual task features. The general principles highlighted by this study are applicable to dynamic situations. For example, with practice, decision makers should be able to learn to identify the time at which to intervene to achieve the maximal effect during dynamic decision making.     

偏序集上蕴涵代数的素滤子

偏序集上的蕴涵代数是取值于偏序集上的蕴涵逻辑联结词的一种代数抽象.以偏序集上蕴涵代数中由蕴涵算子引入的逻辑运算t-余范为工具,讨论了偏序集上蕴涵代数的一些性质,然后引入了偏序集上蕴涵代数的素滤子的概念,讨论了素滤子在一定条件下的性质,并给出了一个MP滤子成为素滤子的条件.     

基于动态自适应t分布变异的人群搜索算法

针对人群搜索算法在进化后期大量个体聚集局部最优时,易陷入局部最优,搜索精度低的缺陷,提出一种基于t分布变异的人群搜索算法.算法使用动态自适应方式确定变异步长,引入t分布变异算子以融合柯西变异和高斯变异的优点,促进算法在进化早期具备良好的全局探索能力,在进化后期收获较强的局部开发能力,增加种群的多样性;采用边界缓冲墙策略处理越界问题,避免越界个体聚集在边界值上的缺陷.实验结果表明,算法比基本人群搜索算法具有更高的寻优精度和收敛速度,是一种有效的算法.     

Derivative-Free Filter Simulated Annealing Method for Constrained Continuous Global Optimization

In this paper, a simulated-annealing-based method called Filter Simulated Annealing (FSA) method is proposed to deal with the constrained global optimization problem. The considered problem is reformulated so as to take the form of optimizing two functions, the objective function and the constraint violation function. Then, the FSA method is applied to solve the reformulated problem. The FSA method invokes a multi-start diversification scheme in order to achieve an efficient exploration process. To deal with the considered problem, a filter-set-based procedure is built in the FSA structure. Finally, an intensification scheme is applied as a final stage of the proposed method in order to overcome the slow convergence of SA-based methods. The computational results obtained by the FSA method are promising and show a superior performance of the proposed method, which is a point-to-point method, against population-based methods.     

Using Dynamic Geometry Software to Simulate Physical Motion

In this paper we analyse to what extent the computational model of the geometry implemented in a dynamic geometry environment provides models for physical motion, focusing on the continuity issues related to motion. In particular, we go over the utility of dynamic geometry environments to simulate the motion of mechanical linkages, as this activity allows us to compare, by means of dynamic drawings, the computable representation of geometric properties with the real motion of a mechanism. Analysing a simple example, we provide theoretical foundations for particular behaviours observed in the motion of a picture on the screen, which require a subtle interpretation to be understood in a purely physical context. In this way, we reflect on some requirements imposed by the computable representation of knowledge. We consider this work to be a necessary step to determine didactic consequences related to students' perceptions of the moving displays; in particular those concerning the uses of the dragging mode as a tool not only for automatic drawing of many instances of a construction,but also to produce continuous motion. This revised version was published online in July 2006 with corrections to the Cover Date.     

基于两阶段求解策略的动态电动车辆路径优化研究

由于政府对新能源汽车的补贴政策和市区对燃油车限行政策的实时,越来越多的物流公司在城市配送中广泛采用电动汽车。然而,电动车续航里程受限,需要在途充电或者换电,同时客户需求的动态性以及充/换电设施的排队等现实因素也应该被考虑。为此,提出了分阶段策略求解动态电动车辆路径优化问题,并建立了两阶段的EVRP模型。其中第一阶段针对静态客户建立了静态EVRP模型,第二阶段在设计了换电站及动态客户插入策略的基础上,建立了动态EVRP模型以路径更新策略。最后,设计改进的CW-TS混合启发式算法来求解静态模型,设计贪婪算法求解动态模型。实验结果表明,模型与算法具有较好的适用性和有效性。