A memory-type control chart utilizes previous information for chart construction.An example of a memory-type chart is an exponentially-weighted moving average(EWMA)control chart.The EWMA control chart is well-known an...A memory-type control chart utilizes previous information for chart construction.An example of a memory-type chart is an exponentially-weighted moving average(EWMA)control chart.The EWMA control chart is well-known and widely employed by practitioners for monitoring small and moderate process mean shifts.Meanwhile,the EWMA median chart is robust against outliers.In light of this,the economic model of the EWMA and EWMA median control charts are commonly considered.This study aims to investigate the effect of cost parameters on the out-of-control average run lengthðARL_(1)Þin implementing EWMA and EWMA median control charts.The economic model was used to compute the ARL_(1) parameter.The 14 input parameters were identified and the analysis was carried out based on the one-parameter-at-a-time basis.When the input parameters change based on a predetermined percentage,the ARL_(1) is affected.According to the results of the EWMA chart,nine input parameters had an effect andfive input parameters had no effect on the ARL_(1) parameter.Further,only seven of the 14 input parameters had an effect on the ARL_(1) of the EWMA median chart.However,the effect of each input parameter on the ARL_(1) was different.Moreover,the ARL_(1) for the EWMA median chart was smaller than the EWMA chart.This analysis is crucial to observe and determine the input parameters that have a significant impact on the ARL_(1) of the EMWA and EWMA median control charts.Hence,practitioners can obtain an overview of the influence of the input parameters on the ARL_(1) when implementing the EWMA and EWMA median control charts.展开更多
Rahim and Banerjee [1] developed a general model for the optimal design of x-control charts. The model minimizes the expected cost per unit time. The heart of the model is a theorem that derives the expected total cos...Rahim and Banerjee [1] developed a general model for the optimal design of x-control charts. The model minimizes the expected cost per unit time. The heart of the model is a theorem that derives the expected total cost and the expected cycle length. In this paper an alternative simple proof for the theorem is provided based on mathematical induction.展开更多
Concrete in reinforced concrete structure (RC) is generally under significant compressive stress load. To guarantee required quality and ductility, various tests have to be conducted to measure the concrete’s compres...Concrete in reinforced concrete structure (RC) is generally under significant compressive stress load. To guarantee required quality and ductility, various tests have to be conducted to measure the concrete’s compressive strength based on ACI (American Concrete Institute) code. Investigations of recent devastating collapses of structures around the world showed that some of the collapses directly resulted from the poor quality of the concrete. The lesson learned from these tragedies is that guaranteeing high quality of concrete is one of the most important factors ensuring the safety of the reinforced concrete structure. In order to ensure high quality of concrete, a new method for analyzing and evaluating the concrete production process is called for. In this paper, the indices of fit and stable degree are proposed as basis to evaluate the fitness and stability of concrete’s compressive strength. These two indices are combined to define and evaluate the quality index of the compressive strength of concrete. Prin-ciples of statistics are used to derive the best estimators of these indices. Based on the outcome of the study, a concrete compres-sive strength quality control chart is proposed as a tool to help the evaluation process. Finally, a new evaluation procedure to assess the quality control capability of the individual concrete manufacturer is also proposed.展开更多
介绍了多变量统计过程控制(multivariate statistical process control,MSPC)的基本概念和有关背景。描述了MSPC实施的基本流程以及常用统计量与控制图。强调了MSPC在药品生产过程中的重要作用,特别是中药领域,为药品生产过程质量控制...介绍了多变量统计过程控制(multivariate statistical process control,MSPC)的基本概念和有关背景。描述了MSPC实施的基本流程以及常用统计量与控制图。强调了MSPC在药品生产过程中的重要作用,特别是中药领域,为药品生产过程质量控制方法的选择提供参考。总结了MSPC的优势和不足,并展望了MSPC在药品生产和质量控制方面的发展趋势。展开更多
为了更好地监控不同生产环节下高温大曲的品质,对参与高温大曲发酵过程中重要风味成分前体氨基酸含量进行全面、准确的控制,该文通过收集制曲车间不同生产环节下高温大曲样品,采用超高效液相色谱-质谱-一测多评(ultra-high-performance ...为了更好地监控不同生产环节下高温大曲的品质,对参与高温大曲发酵过程中重要风味成分前体氨基酸含量进行全面、准确的控制,该文通过收集制曲车间不同生产环节下高温大曲样品,采用超高效液相色谱-质谱-一测多评(ultra-high-performance liquid chromatography high-resolution mass spectrometry-quantitative analysis of multi-components by single-marker,UPLC-HRMS-QAMS)法测定9种重要风味成分前体氨基酸含量,同时,基于Minitab软件利用休哈特控制图中单值-移动极差控制图建立不同生产环节下高温大曲品质监测的质量控制图。结果表明,UPLC-HRMS-QAMS法具有良好线性关系(R^(2)>0.9970),待测氨基酸检出限、定量限低,可满足快速、准确定性定量分析高温大曲中多种重要风味成分前体氨基酸含量的目的,基于此,结合质量控制图可建立监测高温大曲生产过程中品质变化的单值-移动极差控制图,这为不同生产批次下高温大曲的品质监测提供了新思路,有助于提升高温大曲的质量控制水平,进而为制曲车间生产工艺提供技术参考,为实现企业优质优产提供数据支撑及技术保障。展开更多
In light of rapid development of customer requirements, control procedures of quality concept use multivariate analysis. This is because of recent advances in information technology and in recording. The charting proc...In light of rapid development of customer requirements, control procedures of quality concept use multivariate analysis. This is because of recent advances in information technology and in recording. The charting procedures are based on Mahalanobis distance but their performance needs normality and a type-I error rate choice. The DD-diagram is an alternative scheme that uses data depth to avoid these conditions rarely met in practice. For a given error-free sample, the performance of DD-diagram and that of multivariate EWMA control procedures are compared through a real example on individual observations taken from a multivariate quality process.展开更多
Nowadays, with the rapid progress and development of the Chinese society, people’s material level has been continuously improved, and the demand for electricity has also been increasing year by year. For thermal powe...Nowadays, with the rapid progress and development of the Chinese society, people’s material level has been continuously improved, and the demand for electricity has also been increasing year by year. For thermal power plants, it is of great importance to strictly control the feedwater quality and to conduct real-time tracking and supervision, as well as to ensure the safety of the production process. In this paper, we take the boiler feedwater quality in the production process as the research object. First of all, the cause-and-effect diagram is used to find out the reasons for the deviation of feedwater quality;Secondly, each index of feedwater is analyzed by multiple linear regression method to find out the key variables affecting the change of its pH value, so as to develop and implement improvement measures;Finally, the pH value is compared and verified by control chart and process capability analysis, and relevant improvement suggestions and countermeasures are proposed.展开更多
基金funded by the Universiti Kebangsaan Malaysia,Geran Galakan Penyelidikan,GGP-2020-040.
文摘A memory-type control chart utilizes previous information for chart construction.An example of a memory-type chart is an exponentially-weighted moving average(EWMA)control chart.The EWMA control chart is well-known and widely employed by practitioners for monitoring small and moderate process mean shifts.Meanwhile,the EWMA median chart is robust against outliers.In light of this,the economic model of the EWMA and EWMA median control charts are commonly considered.This study aims to investigate the effect of cost parameters on the out-of-control average run lengthðARL_(1)Þin implementing EWMA and EWMA median control charts.The economic model was used to compute the ARL_(1) parameter.The 14 input parameters were identified and the analysis was carried out based on the one-parameter-at-a-time basis.When the input parameters change based on a predetermined percentage,the ARL_(1) is affected.According to the results of the EWMA chart,nine input parameters had an effect andfive input parameters had no effect on the ARL_(1) parameter.Further,only seven of the 14 input parameters had an effect on the ARL_(1) of the EWMA median chart.However,the effect of each input parameter on the ARL_(1) was different.Moreover,the ARL_(1) for the EWMA median chart was smaller than the EWMA chart.This analysis is crucial to observe and determine the input parameters that have a significant impact on the ARL_(1) of the EMWA and EWMA median control charts.Hence,practitioners can obtain an overview of the influence of the input parameters on the ARL_(1) when implementing the EWMA and EWMA median control charts.
文摘Rahim and Banerjee [1] developed a general model for the optimal design of x-control charts. The model minimizes the expected cost per unit time. The heart of the model is a theorem that derives the expected total cost and the expected cycle length. In this paper an alternative simple proof for the theorem is provided based on mathematical induction.
基金Project (No. NSC92-2213-e-167-001) supported by the National Science Council, Taiwan, China
文摘Concrete in reinforced concrete structure (RC) is generally under significant compressive stress load. To guarantee required quality and ductility, various tests have to be conducted to measure the concrete’s compressive strength based on ACI (American Concrete Institute) code. Investigations of recent devastating collapses of structures around the world showed that some of the collapses directly resulted from the poor quality of the concrete. The lesson learned from these tragedies is that guaranteeing high quality of concrete is one of the most important factors ensuring the safety of the reinforced concrete structure. In order to ensure high quality of concrete, a new method for analyzing and evaluating the concrete production process is called for. In this paper, the indices of fit and stable degree are proposed as basis to evaluate the fitness and stability of concrete’s compressive strength. These two indices are combined to define and evaluate the quality index of the compressive strength of concrete. Prin-ciples of statistics are used to derive the best estimators of these indices. Based on the outcome of the study, a concrete compres-sive strength quality control chart is proposed as a tool to help the evaluation process. Finally, a new evaluation procedure to assess the quality control capability of the individual concrete manufacturer is also proposed.
文摘介绍了多变量统计过程控制(multivariate statistical process control,MSPC)的基本概念和有关背景。描述了MSPC实施的基本流程以及常用统计量与控制图。强调了MSPC在药品生产过程中的重要作用,特别是中药领域,为药品生产过程质量控制方法的选择提供参考。总结了MSPC的优势和不足,并展望了MSPC在药品生产和质量控制方面的发展趋势。
文摘为了更好地监控不同生产环节下高温大曲的品质,对参与高温大曲发酵过程中重要风味成分前体氨基酸含量进行全面、准确的控制,该文通过收集制曲车间不同生产环节下高温大曲样品,采用超高效液相色谱-质谱-一测多评(ultra-high-performance liquid chromatography high-resolution mass spectrometry-quantitative analysis of multi-components by single-marker,UPLC-HRMS-QAMS)法测定9种重要风味成分前体氨基酸含量,同时,基于Minitab软件利用休哈特控制图中单值-移动极差控制图建立不同生产环节下高温大曲品质监测的质量控制图。结果表明,UPLC-HRMS-QAMS法具有良好线性关系(R^(2)>0.9970),待测氨基酸检出限、定量限低,可满足快速、准确定性定量分析高温大曲中多种重要风味成分前体氨基酸含量的目的,基于此,结合质量控制图可建立监测高温大曲生产过程中品质变化的单值-移动极差控制图,这为不同生产批次下高温大曲的品质监测提供了新思路,有助于提升高温大曲的质量控制水平,进而为制曲车间生产工艺提供技术参考,为实现企业优质优产提供数据支撑及技术保障。
文摘In light of rapid development of customer requirements, control procedures of quality concept use multivariate analysis. This is because of recent advances in information technology and in recording. The charting procedures are based on Mahalanobis distance but their performance needs normality and a type-I error rate choice. The DD-diagram is an alternative scheme that uses data depth to avoid these conditions rarely met in practice. For a given error-free sample, the performance of DD-diagram and that of multivariate EWMA control procedures are compared through a real example on individual observations taken from a multivariate quality process.
文摘Nowadays, with the rapid progress and development of the Chinese society, people’s material level has been continuously improved, and the demand for electricity has also been increasing year by year. For thermal power plants, it is of great importance to strictly control the feedwater quality and to conduct real-time tracking and supervision, as well as to ensure the safety of the production process. In this paper, we take the boiler feedwater quality in the production process as the research object. First of all, the cause-and-effect diagram is used to find out the reasons for the deviation of feedwater quality;Secondly, each index of feedwater is analyzed by multiple linear regression method to find out the key variables affecting the change of its pH value, so as to develop and implement improvement measures;Finally, the pH value is compared and verified by control chart and process capability analysis, and relevant improvement suggestions and countermeasures are proposed.
