浅谈电力系统中的行政程控交换机

程控交换机在电力行业得到广泛应用,文章简要论述了程控交换机的维护特点和程控交换机在维护和管理过程中的相关事项,并结合工作实际介绍在连江供电公司的使用情况。     

Evaluating Wisconsin dairy producer compliance and potential eligibility for international markets under existing European Union and United States Grade “A” bulk tank somatic cell count compliance criteria

A proposal to lower the bulk tank Somatic Cell Count (SCC) maximum for United States of America (US) Grade “A” milk producers was not adopted by the National Conference on Interstate Milk Shipments in 2011 or 2013. The proposal would have made the US Grade “A” limit consistent with many other international standards, including that of the European Union (EU). Some US states, however, have proactively adopted their own SCC limit to mirror the EU limit. The purpose of this study was to analyze the impacts on Wisconsin dairy producers if Wisconsin should adopt the current EU limit and compliance criterion. Analyses were done on SCC results for Wisconsin Grade “A” and Grade “B” dairy producers reported each month to the Wisconsin Department of Agriculture, Trade and Consumer Protection (WDATCP) during January 1, 2009–December 31, 2012. Results were evaluated against the current US Grade “A” and EU compliance criteria for SCC and the percentage of (producer × month) combinations in compliance was determined. If the current EU SCC compliance criterion was in place, 86.7–94.3 and 64.3–77.3% of Wisconsin Grade “A” and “Grade “B” (producer × month) combinations, respectively, would have been in compliance for the years 2009–2012. Compliance of Wisconsin Grade “A” and Grade “B” producers with the existing US SCC compliance criterion during the same period was 99.3–99.7% and 87.9–93.9% (producer × month combinations) respectively. An analysis of a subset of Wisconsin Grade “A” producers indicated that smaller-volume producers were less likely than larger-volume producers to meet the EU criterion.     

SPC在济钢二炼钢厂生产过程控制中的有效应用

济钢第二炼钢厂通过在生产过程中使用SPC，辨识对产品质量有重大影响的方坯连铸特殊工序，并通过控制连铸工序的中包温度、钢坯[S]含量等重要因素，优化 了生产工艺参数，提高了产品内在质量，使生产过程达到稳定并持续改进。     

统计过程技术在质量控制中的应用

首先介绍了统计过程控制(简称SPC)的概念,并分析了其在过程质量控制中的重要作用。接着着重阐述了SPC的核心监控工具——控制图及其使用程序。最后提出了企业在实施SPC技术应遵从的步骤以及在实施过程中应注意的问题。     

统计过程控制在宝钢的推广应用

统计过程控制（SPC）作为减少过程波动、提高过程控制能力、改进产品质量和稳定性的一种有效工具，被列入了宝钢股份重点推广的管理项目之一。宝钢股份对新成立的钢铁制造单元（例如梅钢公司、不锈钢分公司、特殊钢分公司）推广和应用SPC进行了探索。本文着重阐述宝钢股份在新成立的各钢铁制造单元推广SPC的做法、主要步骤以及关键要点等。     

基于Wilcoxon秩和检验的多元非参数控制图

在统计过程控制(SPC)中,对多元数据的监测仍然是一个重要且具有挑战性的问题。当缺乏或有限的关于潜在过程分布的认知时,特别是当过程测量是多变量的时候,非参数控制图在统计过程控制(SPC)中是有用的。文章基于Wilcoxon秩和检验结合广义加权移动平均(GWMA)控制方案来制定图表统计量,得到一个新的多元非参数控制图,用于监测多元数据的位置参数变化。文章的理论和数值研究表明,所提出的控制图能够为任意数据分布位置偏移检测提供令人满意的性能。     

测量系统分析及其监控策略

本文论述了测量系统波动源分离的两种方法:测量系统分析、田口方法,构造了测量系统本身的统计过程控制图——基于方差分量控制的控制图,以达到对测量过程本身的统计过程控制目的。最后给出了综合运用测量系统分析及监控技术的策略图。     

SPC技术在多品种小批量数控车削中的应用

针对多品种、小批量生产中,由于样本数据不足而无法直接使用传统SPC(统计过程控制)的问题,构造数据转换模型,将工序相似的质量数据转换为同分布指标,扩大了样本容量,使SPC技术能够方便的应用于多品种、小批量零件的数控车削之中。     

浅析物流业的SPC技术应用

目前，中国的物流产业方兴未艾，SPC技术作为一种过程控制方法，运用数理统计和概率论原理，及时发现物流过程中的异常情况，从而及时采取措施，使物流过程不断趋于受控状态。SPC技术是科学的物流事前管理，是物流成功的第一步．本文用实例说明SPC技术在物流业的具体应用以及在应用过程中应注意的一些问题。     

A new SPRT chart for monitoring process mean and variance

This article proposes a new control chart (called the ABS SPRT chart) for Statistical Process Control (SPC) based on Sequential Probability Ratio Test (SPRT). This chart is able to monitor the mean and variance of a variable x simultaneously by inspecting the absolute sample shift |x−μ₀| (where μ₀ is the in-control mean or target value of x). The ABS SPRT chart is designed by an optimization algorithm, aiming at minimizing the Average Extra Quadratic Loss (AEQL) over the process shift domain. The results of intensive performance studies show that the ABS SPRT chart not only uniformly outperforms the CUSUM chart with a Variable Sample Size (VSS) feature, but is also more effective than a 2-SPRT scheme which incorporates a lower-sided SPRT chart and an upper-sided one. From a holistic viewpoint, the ABS SPRT chart detects process shifts in mean and variance faster than the VSS CUSUM chart and 2-SPRT scheme by more than 30% and 13%, respectively. Noteworthily, the design of an ABS SPRT chart is relatively easier than that of a VSS CUSUM chart, and much simpler than the design of a 2-SPRT scheme.