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 共查询到17条相似文献,搜索用时 125 毫秒
1.
莫茜  罗毅 《中国工程科学》2008,10(11):65-68
利用petri网直观图形化特点建立装配模型,并根据petri网原理得出可行装配序列。影响可行装配序列的大部分因素是定性的、模糊的、非数值的,将装配序列看作灰色系统,采用灰色聚类决策方法对可行序列进行评估。分析了影响因素的灰色分类并且研究了灰色聚类决策步骤。实例分析表明,该方法为petri网原理所得可行序列进行正确的评估并且得出决策向量。  相似文献   

2.
激光通信系统性能的灰色聚类分析   总被引:3,自引:0,他引:3  
激光通信系统需要评价和定量分析,且存在多个评价指标.针对评价指标的模糊性、相对性和多样性,为了对激光通信系统进行定量评价,采用灰色系统理论中的灰色聚类分析法.首先对具有模糊性和相对性的评价指标进行灰量白化,然后将激光通信系统按照聚类指标进行灰色聚类,计算不同激光通信系统所有指标的综合聚类效果,最后以聚类类型作为各系统定量评价的依据.该方法将多指标决策问题转换为单一指标决策问题,它是一种定量评价激光通信系统的新方法.  相似文献   

3.
高帅  朱丽萍  李永锋 《包装工程》2021,42(6):198-205
目的 对老年人APP用户界面配色进行评价.方法 首先采用文献研究与焦点小组法,构建老年人APP用户界面配色评价体系;其次采用层次分析法(AHP)来确定APP用户界面配色评价体系中各评价指标的相对权重;接着根据市场调研与用户访谈的结果,与PCCS色彩体系相结合制作实验样本;然后使用灰色聚类法对实验观测值进行灰色聚类得到聚类系数,并由得到的聚类系数对聚类对象进行聚类;最后根据聚类结果对实验样本进行分类并进行结果分析.结论 本文以老年人医疗 APP 用户界面配色作为研究案例,结果验证了基于灰色聚类法的老年人APP用户界面配色评价方法的可行性与有效性.  相似文献   

4.
台阶爆破效果评价是爆破生产过程中一个重要环节,直接影响到后续施工的效率。为了解台阶爆破效果,建立灰色聚类评估模型,利用混合中心点三角白化权函数,对灰色聚类法进行优化。根据台阶爆破的特点,选取大块率、松散系数、根底率、后裂距离、振动速度、飞散距离作为影响台阶爆破效果的评价指标。结合层次分析法和CRITIC分别对评价指标的主观权重和客观权重进行赋值,克服传统指标权重赋值主观性大和数据差异性敏感较大的问题;提出了一种基于离差平方和的最优组合赋权方法,建立台阶爆破效果评价的最优组合赋权-灰色聚类评估模型;以洪水台土石方平场工程项目4次深孔台阶爆破效果来检验模型的有效性和实用性,分析台阶爆破效果评价等级,确定逐孔起爆3.5 m间距为最优台阶爆破方案。  相似文献   

5.
身管是火炮武器的重要部分,其性能状态决定了火炮的使用寿命.身管从开始使用到报废是一个逐渐的过程,目前多以身管寿命作为评价身管性能状态的指标,很少有对身管性能状态的细化分级.而正确评估身管当前的性能状态,就显得极为重要,这将极大地提高火炮武器的使用效率.运用灰色系统理论,建立灰色聚类评估模型,通过分析火炮身管性能状态的各种评估指标,综合评价火炮身管的性能状态,对战时作战协调具有明显的指导意义.  相似文献   

6.
为了比较基于灰色欧几里德关联度的聚类方法与基于邓氏灰色关联度的聚类方法在煤种聚类中的应用效果,选取5种不同煤种的25个煤样为研究对象,测量其发热量、灰分、挥发分和硫分,并以此为基本参数,按照两类聚类方法的基本原理实现了所选煤样的聚类.结果表明,基于灰色欧几里德关联度的聚类方法的准确度为68%,基于邓氏灰色关联度的聚类方法的准确度达96%.  相似文献   

7.
机械产品综合质量的灰色评价   总被引:3,自引:0,他引:3  
运用灰色聚类理论,按各项要求指标抽样检测产品,并将产品各项指标的质量情况进行灰聚类归纳运算,判断产品所属灰类,从而更全面合理地评定出产品的综合质量。  相似文献   

8.
聚类分析法作为水环境质量评价的新方法已引起人们越来越多的关注。本文运用灰色聚类法对氵舞水洪江段水环境质量进行了综合评价。  相似文献   

9.
一种基于GA的聚类集成算法   总被引:1,自引:0,他引:1  
提出了一种基于GA的聚类集成算法ECUNGA(ensemble clustering using NMI and GA).算法利用GA搜索一个与聚类集体差异度小的聚类,以此来达到综合聚类集体信息,得到更优秀的聚类的目的.算法相比于传统基于互信息理论的方法,使用GA搜索,提高了搜索的能力且具有较低计算复杂度.最后,在UCI数据集上进行实验,取得了理想的效果.  相似文献   

10.
解广坤  王涛  董志民 《硅谷》2011,(11):30-30,47
驾驶员的指派是完成应急物流中运输配送的重要环节,合理地选择驾驶员是实现应急物资及时准确安全运送到位的重要保障。运用灰色聚类决策,从影响驾驶员选择的五项决策指标入手,求解出各驾驶员关于各灰类的决策系数向量,根据决策系数的大小,判定驾驶员所属的灰类,并确定指派的优先顺序。最后,通过案例分析,说明应急物流中驾驶员的优选采用灰色聚类决策是可行的、有效的。  相似文献   

11.
Nowadays discarded electromechanical products are more and more common, and have done much harm to the ecological environment, human health and natural resources. In order to recycle discarded products effectively, it is necessary to disassemble them properly in an integrated consideration of economic returns and environmental protection. Therefore Disassembly Process Planning has become a key part in Environmentally Conscious Design. Because there may be a combination explosion when the disassembly process of a product with a large number of parts is planned, subassembly identification is often adopted to divide the product into some reasonable subassemblies. This paper uses a method of grey clustering based on grey system theory to perform subassembly identification. The clustered objects are part pairs with adjacency relation in a product, and the clustering indices consist of energy consumption of disassembly, disassembly time, disassemblable direction and diameter of part pair. The indices can be obtained by detailed estimate or direct input from a CAD system via secondary development. After five grey clusters are set up, their whitening weight functions are presented in detail. Several other key problems in subassembly identification based on grey clustering are also expounded, such as obtaining the nondimensional matrix of sample values, determining the weight of clustering index relative to grey cluster. A heat-sealing machine with 80 components is selected as an example to validate the method of subassembly identification based on grey clustering. The identification result of the example is feasible according to experiences, and at the same time it satisfies the requirement of Disassembly Process Planning.  相似文献   

12.
为解决立式加工中心热误差补偿关键技术中温测点难选取的问题,提出了一种基于改进有序聚类法的机床进给系统温测点优化方法。首先,结合试验数据计算反映温测点温度变量与热误差相关性的互信息值,初步筛选机床各部件的温测点,消除测点间的耦合性;然后,根据筛选出的温测点,通过建立类直径矩阵和计算各类的最小误差函数,获得温度变量分类;最后,基于多元线性回归建立包含多个不同温测点的热误差模型,并对模型进行统计学综合分析,确定了最佳聚类数和最佳温测点。结果表明:在不同加工条件下采用改进有序聚类法建立的热误差模型的均方根误差和平均残差分别降至1.05 μm和1 μm以下,相较于采用传统有序聚类法和灰色关联度模糊聚类法建立的热误差模型,它具有更高的热误差预测精度和更好的鲁棒性。所提方法在中小型加工中心进给系统的温测点研究中具有广阔的应用前景。  相似文献   

13.
《成像科学杂志》2013,61(2):134-145
Abstract

One of the main problems related to unsupervised change detection methods based on the ‘difference image’ lies in the lack of efficient automatic techniques for discriminating between changed and unchanged pixels in the difference image. Such discrimination is usually performed by using empirical strategies or manual trial-and-error procedures, which affect both the accuracy and the reliability of the change detection process. To overcome such drawbacks, in this paper, we propose an automatic techniques (based on the clustering characteristic of 3D histogram) for the analysis of the difference image. The 3D histogram is formed by pixel grey levels, contiguous average grey levels and local average grey levels of the difference image. First, the optimal plane threshold and plane direction are searched by using maximal entropy principle based on the clustering characteristic of 3D histogram. Then, by using the optimal plane threshold and plane direction, a plane is established to segment the 3D histogram into changed clustering and unchanged clustering. Finally, the changed pixels in the difference image are discriminated according to the segmentation of 3D histogram. The theoretical analysis and experiment results confirm the effectiveness of the proposed method.  相似文献   

14.
Microgrid (MG) clustering is regarded as an important driver in improving the robustness of MGs. However, little research has been conducted on providing appropriate MG clustering. This article addresses this shortfall. It proposes a novel multi-objective optimization approach for finding optimal clustering of autonomous MGs by focusing on variables such as distributed generation (DG) droop parameters, the location and capacity of DG units, renewable energy sources, capacitors and powerline transmission. Power losses are minimized and voltage stability is improved while virtual cut-set lines with minimum power transmission for clustering MGs are obtained. A novel chaotic grey wolf optimizer (CGWO) algorithm is applied to solve the proposed multi-objective problem. The performance of the approach is evaluated by utilizing a 69-bus MG in several scenarios.  相似文献   

15.
A good process understanding is the foundation for process optimization, process monitoring, end-point detection, and estimation of the end-product quality. Performing good process measurements and the construction of process models will contribute to a better process understanding. To improve the process knowledge it is common to build process models. These models are often based on first principles such as kinetic rates or mass balances. These types of models are also known as hard or white models. White models are characterized by being generally applicable but often having only a reasonable fit to real process data. Other commonly used types of models are empirical or black-box models such as regression and neural nets. Black-box models are characterized by having a good data fit but they lack a chemically meaningful model interpretation. Alternative models are grey models, which are combinations of white models and black models. The aim of a grey model is to combine the advantages of both black-box models and white models. In a qualitative case study of monitoring industrial batches using near-infrared (NIR) spectroscopy, it is shown that grey models are a good tool for detecting batch-to-batch variations and an excellent tool for process diagnosis compared to common spectroscopic monitoring tools.  相似文献   

16.
In this paper, we argue that grey differential equation models are useful in repairable system modeling. The arguments starts with the review on GM(1,1) model with equal- and unequal-spaced stopping time sequence. In terms of two-stage GM(1,1) filtering, system stopping time can be partitioned into system intrinsic function and repair effect. Furthermore, we propose an approach to use grey differential equation to specify a semi-statistical membership function for system intrinsic function times. Also, we engage an effort to use GM(1,N) model to model system stopping times and the associated operating covariates and propose an unequal-gapped GM(1,N) model for such analysis. Finally, we investigate the GM(1,1)-embed systematic grey equation system modeling of imperfectly repaired system operating data. Practical examples are given in step-by-step manner to illustrate the grey differential equation modeling of repairable system data.  相似文献   

17.
Zvi Drezner 《OR Spectrum》2006,28(3):417-436
In this paper we propose a model which aims at selecting a tight cluster from a set of points. The same formulation applies also to the grey pattern problem where the objective is to find a set of black dots in a rectangular grid with a given density so that the dots are spread as evenly as possible. A branch and bound algorithm and five heuristic approaches are proposed. Computational results demonstrate the efficiency of these approaches. Seven grey pattern problems are solved to optimality and for eight additional grey pattern problems the best known solution is improved. The cluster problem on a network is solved for 40 problems with the number of points ranging between 100 and 900 and the size of the cluster ranging between 5 and 200. Twenty one problems were solved optimally and the remaining 19 problems were heuristically solved in a very short computer time with excellent results.  相似文献   

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