自相关过程的质量控制图

常规控制图应用的基本假设是从过程得到的测量值彼此独立,但许多连续型的制造业生产过程(例如化学和制药)往往存在自相关,此时常规控制图容易虚发警报。基于数据的样本自相关函数,本文改进了常规控制图的控制界限,使之适用于自相关过程,并运用常规X-s控制图和本文修正的X控制图对一个实际案例进行了比较分析,结果表明本文修正的X控制图可正确地判断过程是否处于受控状态。     

基于情景推演与网络图技术的应急处置模式研究

突发事件应急处置工作时间紧、任务重、压力大,要求工作人员分秒必争,传统的"兵来将挡,水来土淹"的应急处置模式已不再适用,时间压力要求以一种新型、高效的处置模式来代替传统模式.研究在有关突发事件情景演变的研究基础之上,结合项目计划与控制中的网络图技术,提出了一种基于情景推演与网络图技术的应急实时处置模式,确定了这种处置模式的流程.以2010年大连输油管道爆炸事件为例,对传统的处置模式与基于情景推演与网络图技术的应急处置模式做了比较分析,分析结果证明,基于情景推演与网络图技术的应急处置可有效节省时间45小时40分钟,这对于分秒必争的应急处置工作意义非常重大.     

基于Bayes统计的蔬菜产品质量安全监控系统研究

利用中山市蔬菜产品抽样检测数据,运用Bayes统计方法,建立了蔬菜产品污染指数:并根据休哈特控制图原理,确定μ、μ+2σ、μ+3σ三条监控限,将蔬菜产品质量安全状况水平分成"优秀"、"良好"、"轻度污染"、"污染"四个监控区域,建立蔬菜产品质量安全监控图。为广大市民、政府部门、农产品市场和生产部门提供及时的蔬菜产品污染水平和质量状况信息。     

利用统计分析提高经济效益

本文通过直方图分析和一元线性回归分析的两个应用实例，介绍如何利用统计分析提高经济效益。     

基于测量质量损失函数的控制图控制界限的优化

控制界限和抽样间隔是控制图的两个基本参数。常规控制图是基于3σ原理确定的控制界限,该控制界限是在大量试验基础上依据经验确定的,并没有精确的公式推导.对于抽样间隔,常规控制图也没有明确的规定。田口博士的质量损失函数可以很好的解决质量经济性方面的一些问题.利用田口博士的理论,通过确定适宜的二次测量质量损失函数,可以确定控制图的最佳控制界限和最佳抽样间隔.文章简要介绍了常规控制图原理和田口博士的质量损失函数,重点叙述了田口博士反馈控制系统的测量质量损失函数,在此基础上,研究了控制图最佳控制界限和最佳抽样间隔,并且通过具体实例验证了该控制图良好的经济性.     

Comparative Thermodynamic Analysis of the Bi-Ga0.1Sb0.9 Section in the Bi-Ga-Sb System

Results of the comparative thermodynamic analysis of the Bi-Ga_0.1Sb_0.9 section in theBi-Ga-Sb system are given in this paper. Experimental calorimetric investigations were done according to Oelsen's method, while for the thermodynamic prediction Chou's general solution model was applied. Activities, activity coefficients, partial molar quantities for bismuth and integral molar quantities were obtained at a temperature of 1073 K. Based on obtained cooling curves, DTA and SEM results for the investigated samples, phase diagram of the investigated section is constructed and presented in this paper, too. This revised version was published online in July 2006 with corrections to the Cover Date.     

Generalized composite degradation kinetics for polymeric systems under isothermal and nonisothermal conditions

A composite degradation methodology is extended to the conversion-dependence function in order to explain the importance of multiple reaction mechanisms which might be considered to be involved in degradation processes. Based on two elementary reaction mechanisms, a specific form of the model equation is derived, which is capable of describing various types of degradation behavior showing sigmoidal rate as well as deceleratory rate. The conversion-dependence function is derived to be independent of the Arrhenius-type reaction constant or temperature, and thus the kinetic parameters are determined by analytic methods that have been developed for isothermal and dynamic-heating experiments without any modification or additional assumptions. The developed model equation is tested by predicting the isothermal master curve of polyether-ether-ketone (PEEK), which is used as a model system in this study. The activation energies of the model system are analyzed using comparable methods for isothermal and dynamic experiments, which compare favorably in terms of the activation energy as a function of conversion. The resulting model equation, based on the kinetic parameters determined by isothermal experiments, can accurately predict both isothermal and dynamic-heating thermogravimetry utilizing the same constants and identical reaction mechanisms without additional assumption.     

Computation of the generalized Debye functionsδ(x,y) andD(x,y)

Automatic computer programs (BASIC-PLUS) are developed to calculate Debye functions also for non integer exponents. Functions of this type occur in the heat capacity analysis of polymer crystals, if simple continuum approximations are used. The heat capacity of completely crystalline polyethylene is calculated and compared with experimental data.