基于粗糙集理论的冶金企业备件供应商选择多属性决策

备品备件货物品种多和可供选择供应商多的特点,使得冶金企业对备品备件供应商的管理比大宗原燃料供应商的管理更加复杂.基于粗糙集理论,运用多属性决策方法研究了供应商选择问题.首先,在选择决策指标体系的基础上,采用粗糙集理论分析历史指标数据与供应商选择结果之间的关系,从而确定每个指标的客观权重,再结合主观赋权,得到每个指标的综合权重.其次,基于主、客观综合权重及数据的规范化处理结果,对候选供应商进行综合评价.最后,用案例验证了本方法的可行性和有效性.     

模拟故障诊断中的容差处理方法研究

基于斜率故障模型的故障诊断方法较好地解决了线性电路的软故障和硬故障诊断问题,是一种很有价值的故障模型,但是容差问题使该方法不实用,基于此,给出了新的容差处理方法.首先斜率故障模型的公共点(由无故障时两个选定测点的电压值确定)不再是一个定值,而是在实际电路运行中获得,它包含了实际电路元件的容差信息.其次,受容差影响,元件斜率特征是一个扇形区域,该扇形区域可以通过计算或者仿真得到.该方法能较好地解决斜率故障模型中的容差问题.     

一种基于粗糙集属性度量的集成分类器

为了准确度量属性的重要性,从基于粗糙集的属性度量视角,提出一种基于混合度量机制的属性评价方法,该方法从不同的信息粒度分析属性的重要性.在混合度量机制中,根据数据分布特点引入参数权重因子.在此基础上,构造一种基于粗糙集属性度量机制的集成分类器.通过实验结果和比较分析表明,所提出的方法能有效地降低数据的属性维度,相比较于单一属性度量准则,分类器具有更好的分类性能.     

基于改进熵权法—未确知测度模型的黄金洞尾矿库综合安全评价

针对尾矿库安全评价中存在的不确定性问题,以黄金洞尾矿库为例,引入未确知测度理论,分析评价对象与评价指标之间的关系,建立一个包含5个影响因素和18个影响因子的尾矿库综合安全指标评价体系,结合基于层次分析法—熵权法综合确定指标权重,构建基于改进熵权法—未确知测度模型.根据该模型的指标评价体系和分级模式确定指标测度函数,代入...     

含有自校正模型的加权多模型自适应控制

研究了含有大范围参数不确定性离散时间被控对象的加权多模型自适应控制问题(包括模型集构建和加权算法分析).通过构建含有自校正模型和多个固定模型的模型集覆盖并逼近被控对象,在模型输出误差可分的前提下,采用基于模型输出误差性能指标的加权算法,并依据固定模型中是否包含真实被控对象模型的不同情形分析加权算法的收敛性.在权值收敛的前提下,利用虚拟等价系统理论,分析了参数未知线性时不变和参数跳变的情形,在不依赖于特定局部控制算法的基础上,证明了此种模型集构建下的加权多模型自适应控制系统的稳定性和收敛性,放宽了先期加权多模型自适应控制系统稳定性分析中关于模型集构建的约束条件.最终,通过计算机MATLAB仿真,验证了此类加权多模型自适应控制系统的收敛性和闭环稳定性.     

基于嫡权的TOPSIS农产品物流中心选址模型

利用能够有效反应评价信息自身所包含的信息量的熵权法确定评价指标的客观权重,将加权后的评价信息运用TOPSIS方法进行集结,给出了农产品物流中心选址模型,该模型充分体现了各评价指标之间的差异对评价结果的影响.     

一种不完备信息表的预处理方法

针对不完备信息表预处理问题中的不完备数据的填补问题、冗余属性的约简问题和连续属性的离散化问题进行了研究.应用粗糙集理论,由相容信息表中条件属性与决策属性间的一致性对应关系,定义了划分区间的加法运算,解决了不完备数据填补问题;根据类别概念,定义了差别向量,利用差别向量加法运算删除了冗余属性;根据条件属性与决策属性之间的依赖关系及相对信息熵概念,实现了连续属性的离散化.数值示例和实验结果显示此方法是有效可行的.     

基于粗糙集和信息熵的土地适宜性评价研究

将信息熵理论与粗糙集技术引入土地适宜性评价领域,通过计算指标的信息量,为指标权重的确定提供科学依据,从而有效地避免指标权重确定过程中的主观性.通过福建省武平县城乡建设用地适宜性评价的实际应用进一步验证该方法的有效性,为土地适宜性评价开拓一种新的思路.     

信息表中不完备数据的填补方法

提出了一种基于粗糙集的不完备数据填补方法.本算法以突出信息表的决策规则为主要目的,选取重要断点为主要手段,以分类质量作为迭代约束条件.实验和数值实例表明,本算法不但不会产生冲突规则,而且能够进一步突出决策规则.     

基于改进的RS-TOPSIS模型的岩爆倾向性预测

针对目前岩爆倾向性中预测模型权重确定存在不足导致模型精度不高的现状,为更准确地预测岩爆倾向性,提出综合运用粗糙集理论中的代数观和信息观,确定属性最优权重,并修正岩爆倾向性与评价指标之间的关系,建立岩爆等级理想点矩阵。根据岩爆发生条件,选取岩石脆性指数、切应力指标和弹性应变能指数3项指标作为岩爆判别指标,以国内外20组典型岩爆数据为样本,建立改进的粗糙集—理想点法（RS-TOPSIS）岩爆倾向性预测模型,并应用该模型对玲珑金矿等工程实际进行了岩爆倾向性预测。结果表明：改进后样本预测精度相比于改进前有了显著提高,所建立的模型对实际工程的岩爆倾向性预测效果良好,预测结果更准确。     

基于FCM的多支持向量机模型在高炉炉温预测中的应用

针对高炉炼铁智能控制专家系统中单一支持向量机(SVM)炉温预测模型的改进研究,提出一种基于模糊C均值聚类(FCM)的多支持向量机模型。首先运用模糊C均值聚类对模型训练集进行聚类划分,然后对每一类进行支持向量机的训练,建立相应的子模型,并对测试集中的同一样本点分别进行预测,以测试样本点的输入对应于每一类的隶属度为权值,进行加权求和,最终得到预测值。通过对在线采集的数据分析表明,基于FCM的多支持向量机模型比单一的支持向量机模型在多方面预测性能得到改善,连续预测100炉命中率达86%。     

矿山公司内部经济效果综合比较的集对分析模型

介绍了基于集对分析同一度概念的矿山（集团）公司企业横向综合比较模型及其应用。采用判断矩阵的几何平均方法确定指标的权重,然后求得各方案与查想方案的加权同一度,据此对各方案进行优劣排序。     

Natural and induced tolerance in an immune network model

It has been proposed that the immune system can be partitioned into central and peripheral immune systems. Recently, Carneiro et al. (1996a, b) proposed a network, model incorporating B and T lymphocytes that explicitly accounts for that partition. This model however, had some limitations that are tackled here. Two main changes were introduced: the average idiotypic connectivity is now an explicit function of time based on empirical evidence; and the activation of T lymphocytes by antigen is described by a log-bell shaped dose response curve. The new model, which also accounts for the CIS and PIS distinction, shows more reasonable results since the frequencies of tolerant, immune or autoimmune responses to an antigen are now correct. The model provides a new interpretation for tolerance induction during the neonatal period, and for the adult tolerance by low or high doses of antigen. It predicts that natural tolerance for antigens available during the neonatal period can be kept indefinitely upon their removal, while tolerance induced in the adult stages is rapidly lost upon transient removal of the antigen. A semiquantitative analysis of the model provides a simple explanation for the different results in terms of the frequency at which a limited set of canonical connectivity structures emerge during ontogenesis.     

基于扫描向量的属性约简方法

针对粗糙集理论中属性约简问题,提出了一种基于扫描向量的属性约简方法.根据粗糙集理论知识,定义了一个新概念——差别向量,利用差别向量将信息表转换成差别向量组;根据差别向量的结构特征,定义了差别向量加法法则;运用这个加法法则仅需对差别向量组扫描一次,就可以形成结构简洁却能代表原信息表属性特征的扫描向量.以扫描向量中的属性频率项作为属性约简搜索的启发信息,提高了属性约简效率.数值实例及数据库测试的结果表明该属性约简算法是有效可行的.     

基于概念格粗糙集的采矿方法优选研究

为了正确选择矿山初选的采矿方法,提出基于概念格粗糙集的采矿方法评价体系。综合考虑影响采矿方法选择的众多因素后,对指标进行分层处理,利用改进的粗糙集建立采矿方法评价体系,生成最少决策规则集。属性约简是粗糙集中的核心问题,选择概念格作为约简工具,对条件属性进行约简。将模型用于15种采矿方法的优选,得到了最大可约简属性集,决策规则集的分类质量为100%。最后,将约简概念格与传统粗糙集中的分辨矩阵进行对比,结果表明：概念格在属性约简方面比分辨矩阵更有效,利用概念格的粗糙集构建采矿方法评价体系对矿山生产具有一定的理论指导意义。     

New Mathematical Optimization Model for Construction Site Layout

Layout of temporary construction facilities (objects) is an important activity during the planning process of construction projects. The construction area layout is a complex problem whose solution requires the use of analytical models. Existing popular models employ genetic algorithms that have proven to be useful tools in generating near optimal site layouts. This paper presents an alternative approach based on mathematical optimization that offers several important features and generates a global optimal solution. The construction area consists of an unavailable area that includes existing facilities (sites) and available area in which the objects can be located. The available area is divided into regions that are formulated using binary variables. The locations of the objects are determined by optimizing an objective function subject to a variety of physical and functional constraints. The objective function minimizes the total weighted distance between the objects and the sites as well as among the objects (if desired). The distance can be expressed as Euclidean or Manhattan distance. Constraints that ensure objects do not overlap are developed. The new approach, which considers a continuous space in locating the objects simultaneously, offers such capabilities as accommodating object adjacency constraints, facility proximity constraints, object–region constraints, flexible orientation of objects, visibility constraints, and nonrectangular objects, regions, and construction areas. Application of the model is illustrated using two examples involving single and multiple objects. The proposed model is efficient and easy to apply, and as such should be of interest to construction engineers and practitioners.     

Multiple-Criteria Evaluation for Value Management in Civil Engineering

This paper presents a fuzzy set-based approach for representing and synthesizing information about the different kinds of variables involved in the evaluation of a project’s value. The variables considered can be quantitative crisp or fuzzy as well as qualitative ordinal. The information is given either by a single expert or by a team of experts. The proposed methodology for summarizing and normalizing values aims at contributing to decision-making analysis in the context of multiple-criteria evaluation and group decision making. The conditions that the aggregation function to be used must satisfy are also discussed. The weighted sum is characterized under quite restrictive assumptions, presenting a theorem based on Cauchy’s functional equation. The aggregation function proposed is the weighted sum, with weights computed by a well-known analytic hierarchy process. A design is given of a fuzzy system for evaluating a project’s value in the context of construction in civil engineering.     

基于集对分析同一度的武钢年度经济效益评价

介绍了集对分析同一度的概念及其在多目标评价中的运用,采用判断距阵的几何平均方法确定指标的权重,然后求得各方案与理想方案的加权同一度,据此对各方案进行优劣排序,通过实例对武钢最后４年的年度效益指标进行了评价。     

Postprocessing the Hybrid Method for Addressing Uncertainty in Risk Assessments

In a previous paper in this Journal, a “hybrid method” was proposed for the joint propagation of probability distributions (expressing variability) and possibility distributions (i.e., fuzzy numbers, expressing imprecision or partial ignorance) in the computation of risk. In order to compare the results of the hybrid computation (a random fuzzy set) to a tolerance threshold (a tolerable level of risk), a postprocessing method was proposed. Recent work has highlighted a shortcoming of this postprocessing step which yields overly conservative results. A postprocessing method based on Shafer’s theory of evidence provides a rigorous answer to the problem of comparing a random fuzzy set with a threshold. The principles behind the new postprocessing scheme are presented and illustrated with a synthetic example.     

Sensorimotor prediction and memory in object manipulation.

Notes that when people lift objects of different size but equal weight, they initially employ too much force for the large object and too little force for the small object. However, over repeated lifts of the two objects, they learn to suppress the size–weight association used to estimate force requirements and appropriately scale their lifting forces to the true and equal weights of the objects. Thus, sensorimotor memory from previous lifts comes to dominate visual size information in terms of force prediction. Here the authors ask whether this sensorimotor memory is transient, preserved only long enough to perform the task, or more stable. After completing an initial lift series in which they lifted equally weighted large and small objects in alternation, 24 18–28 yr olds then repeated the lift series after delays of 15 min or 24 hrs. In both cases, participants retained information about the weights of the objects and used this information to predict the appropriate fingertip forces. This preserved sensorimotor memory suggests that participants acquired internal models of the size–weight stimuli that could be used for later prediction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)