面向冷轧带钢表面缺陷的加权模糊层次关联规则挖掘方法

为了克服传统关联规则在解决钢铁工业泛在信息多样性、模糊性和层次性方面的不足,在传统的层次型关联规则挖掘算法基础上,建立层次间的模糊隶属度关系,并引入加权扩展,设计了一种加权模糊层次关联规则算法,并将该算法应用于冷轧带钢生产过程缺陷与缺陷形成原因的关联关系挖掘中。试验表明,该算法不但可以挖掘出缺陷之间的关联关系,同时还能挖掘出不同缺陷与其对应的不同缺陷形成原因之间的关联关系,弥补了传统挖掘算法只能挖掘同种类别数据之间关系的不足。     

全矢关联规则在轴承故障预警中的应用

大型旋转机械设备在发生故障时所造成的损失是不可计算的,因此建立了关联规则库预警模型.首先采用全矢Hilbert对正常运行状态下的同源双通道原始样本数据进行信息融合,然后进行离散化等预处理,建立后期工作所需要的数据库.利用Apriori算法发现滚动轴承八个特征频率幅值数据之间的未知关系,继而用挖掘出的关联规则构建一个规则库.将运行数据通过处理之后与所建立的规则库相匹配,并设立阈值,依据此结果在设备未完全报废之前,及时发出报警信号,达到预警目的 .     

改进的关联规则算法在数据挖掘中的探讨

数据挖掘技术在客户关系管理(CRM)中的有效运用可以从与客户有关的大量数据中挖掘出对企业经营决策有价值的知识和规则。本文根据数据挖掘中关联规则的性质以及钢铁企业的自身特点,在经典关联规则算法APriori算法的基础上提出了一种改进的算法,并利用该算法对数据库进行了关联规则挖掘,得到了隐含在数据库中的有用信息。     

基于CA算法的模糊关联规则在锅炉低NOx排放中的应用

针对火电厂锅炉的NOx排放控制问题,采用CA(competitive agglomeration)算法对影响锅炉NOx排放的主要相关参数进行模糊聚类,得到符合数据分布特征的优化聚类个数和相应的模糊划分矩阵,在此基础上,挖掘出可以指导锅炉低NOx排放运行的模糊关联规则。CA算法克服了FCM(fuzzy c-means)算法聚类个数人为固定的缺点,聚类结果更符合数据的分布特征,特别适合对具有高偏态分布特征的数据进行聚类。通过对挖掘结果分析并进行效果验证,结果表明:本方案挖掘出的模糊关联规则可以有效指导锅炉NOx排放运行在一个较低的水平。     

基于数据立方体的关联规则挖掘方法研究

关联规则挖掘是数据挖掘领域的一个重要研究方向.针对数据立方体的结构特点,给出了一套基于元规则指导的关联规则挖掘方案,最终挖掘出用户真正感兴趣的关联规则.     

基于关联规则的教务信息挖掘

在高校中,教务管理系统每年都产生大量和教学相关的数据,如教师基本信息、学生基本信息、成绩数据及各项测评信息等。这些数据真实的反映了高校的教学情况,但并没有充分利用这些数据来挖掘出有用的决策信息。通过对基于关联规则的教务信息挖掘的研究,把改进的Apriori算法应用在教务信息挖掘中,对影响学生成绩的因素进行分析,确定相互之间的关联规则,以改善教学。     

一种模糊加权关联规则算法及其在流程工业中的应用

采用模糊加权关联规则对流程工业中的大量运行数据进行了分析。阐述了模糊理论和关联规则的内容和性质,在证明模糊关联规则也具有“频繁项集的所有非空子集也必须都是频繁的”基础上,借鉴加权关联规则算法的特点,提出了模糊加权关联规则Fuzzy_WedApriori算法流程,针对不同情况采用不同隶属函数对实际数据进行模糊化,根据此算法的步骤对模糊化的参数点进行处理,得到了有价值的模糊加权规则,为流程工业的生产优化提供了理论依据。     

基于改进决策树算法识别LCD产品质量影响因素

影响液晶显示器(Liquid Crystal Display,LCD)产品合格率的因素众多,在诸多因素中找出影响产品质量的关键因素,是一个有价值的研究领域。采用基于关联规则的C4.5决策树算法对LCD生产数据进行挖掘,该方法首先挖掘出对合格率有影响的关联因素作为新属性,再对所有的新属性生成决策树模型,进而找到影响生产的关键属性。基于关联规则的C4.5决策树算法考虑了联合影响的因素,更深层地挖掘潜在的质量影响因素,同时降低属性的冗余度。实验表明该算法为企业质量管理的改进提供决策支持。     

机械结构对称性实例设计知识挖掘方法研究

针对机械结构对称性实例中存在着大量的设计知识,利用多维模糊数据挖掘的方法从结构对称性实例中挖掘了设计知识,用以指导结构对称性在机械产品结构设计中的科学应用。提出了根据设计需求结合隶属函数特征对实例数据库中待挖掘的数据模糊化处理,借助关联规则挖掘方法 Apriori算法对预处理后的数据库进行了挖掘。挖掘出了结构对称性和产品功能区间、性能区间及约束区间之间的模糊关联规则。结果表明:通过对结构对称性实例进行数据挖掘,建立结构对称性在机械系统中实用的设计知识,是以后进一步研究机械结构对称性应用规律和应用方法的坚实基础。     

基于模糊关联规则的预测系统遗传优化

为提高预测系统中的预测精度,提出了一种基于模糊关联规则的优化的预测系统设计方法。该方法通过两个阶段来实现:首先采用竞争聚集算法得到各数量型属性优化的模糊集个数,从而挖掘出优化的模糊关联规则。在得到用于构建预测系统规则库的模糊关联规则后,采用遗传算法约简冗余规则库,实现精确性和解释性的折衷,以提高预测精度。最后将此方法运用于Abalone样本数据集进行实验分析,证实此方法解决了模糊关联规则的冗余问题,有效提高了预测精度。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

OPTIMIZATION METHOD ON IMPELLER MERIDIONAL CONTOUR AND 3D BLADE

An optimization method for 3D blade and meridional contour of centrifugal or mixed-flow impeller based on the 3D viscous computational fluid dynamics (CFD) analysis is proposed. The blade is indirectly parameterized using the angular momentum and calculated by inverse design method. The design variables are separated into two categories: the meridional contour design variables and the blade design variables. Firstly, only the blade is optimized using genetic algorithm with the meridional contour remained constant. The artificial neural network (ANN) techniques with the training sample data schemed according to design of experiment theory are adopted to construct the response relation between the blade design variables and the impeller performance. Then, based on the ANN approximated relation between the meridional contour design variables and impeller performance, the meridional contour is optimized. Fewer design variables and less calculation effort is required in this method that may be widely used in the optimization of three-dimension impellers. An optimized impeller in a mixed-flow pump, where the head and the efficiency are enhanced by 12.9% and 4.5% respectively, confirms the validity of this newly proposed method.