Control charts for location based on different sampling schemes

Control charts are the most important statistical process control tool for monitoring variations in a process. A number of articles are available in the literature for the X? control chart based on simple random sampling, ranked set sampling, median-ranked set sampling (MRSS), extreme-ranked set sampling, double-ranked set sampling, double median-ranked set sampling and median double-ranked set sampling. In this study, we highlight some limitations of the existing ranked set charting structures. Besides, we propose different runs rules-based control charting structures under a variety of sampling strategies. We evaluate the performance of the control charting structures using power curves as a performance criterion. We observe that the proposed merger of varying runs rules schemes with different sampling strategies improve significantly the detection ability of location control charting structures. More specifically, the MRSS performs the best under both single- and double-ranked set strategies with varying runs rules schemes. We also include a real-life example to explain the proposal and highlight its significance for practical data sets.     

中国货币政策的利率规则——基于金融状况指数的分析

为检验中国中央银行是否已将金融市场状况纳入货币政策的框架,采用HTVPVAR模型的脉冲响应构建中国金融市场状况指数,检验结果显示:以金融市场状况指数为转换变量的STR模型形式的利率规则能较好地拟合实际数据,政策利率对通货膨胀缺口的变动存在非线性调整,且金融市场的景气（不景气）将增强（减弱）货币政策对通货膨胀缺口的反应程度。     

稳压电源的自适应去火弧技术

针对传统基于继电器控制的稳压电源在带负载工作时,档位切换常常伴随火弧现象的问题,设计了一种可广泛 应用于此类稳压电源上的自适应去火弧技术：使用光耦和多级运放完成对零点和电压电流的采样;基于单片机的10量, 实现对继电器的驱动和控制;基于RCC自激震荡原理为系统提供稳定电源;设计了稳压器的完整软件系统程序,并在软 件中应用自适应去火弧算法。实验结果表明：自适应去火弧技术,能够有效地规避火弧现象的产生,并能够根据条件作 出调整。采用自适应去火弧技术的稳压系统达到了设计目标,延长了系统工作寿命。     

外语学习策略研究中存在的主要问题及其对策

探讨了当前国内外外语学习策略研究中存在的一些主要问题,包括术语问题、分类问题、效度和信度问题、研究内容问题、研究方法问题和代表性问题,并针对这些问题提出了相应的对策.     

一种定量敏感性问题的随机化调查方法

在敏感性问题的随机化调查中,既有调查个体是否具有敏感属性的二值敏感性问题,即属性特征问题,又有调查特定人群中敏感指标量的“多少”问题,即定量特征敏感性问题.对于定量特征敏感性问题的调查,E ichhorn,H aryre于1983年提出了一种随机化调查方法,并给出了定量敏感问题指标量均值的一个无偏估计.本文提出一种定量特征敏感性问题的随机化调查方法,得到的结果表明,本文提出的方法优于E ichhorn,H aryre(1983)提出的方法.     

论科技期刊的品牌资本

科技期刊的品牌资本是其生存和发展的关键因素,品牌资本体现了社会效益与经济效益的同一性。品牌资本的价值回归是一个缓慢但却是相当稳定的过程。通过抽样调查和方差分析,定量说明了上述论点的正确性。     

一次计数抽样检验的风险分析

利用抽样检验特征曲线 ,分析了一次计数抽样检验中N ,n ,Ac3个参数的改变对生产者风险和消费者风险的影响     

Designing optimal food safety monitoring schemes using Bayesian network and integer programming: The case of monitoring dioxins and DL-PCBs

Efficient food safety monitoring should achieve optimal resource allocation. In this article, a methodology is presented to optimize the use of resources for food safety monitoring aimed at identifying noncompliant samples and estimating background level of hazards in food products. A Bayesian network (BN) model and an optimization model were combined in a single framework. The framework was applied to monitoring dioxins and dioxin-like polychlorinated biphenyls (DL-PCBs) in primary animal-derived food products in the Netherlands. The BN model was built using a national dataset with monitoring results of dioxins and DL-PCBs in animal-derived food products over a 10-year period (2008–2017). These data were used to estimate the probability of detecting suspect samples with dioxins and DL-PCBs levels above preset thresholds, given certain sample conditions. The results of the BN model were then inserted into the optimization model to compute an optimal monitoring scheme. Model estimates showed that the probability of dioxins and DL-PCBs exceeding threshold limits was higher in laying hen eggs and sheep meat than in other animal-derived food (except deer meat). Compared with the monitoring scheme used in the Netherlands in 2018, the optimal monitoring scheme would save around 10,000 EUR per year. This could be obtained by reallocating monitoring resources from products with lower probability of dioxin and DL-PCBs exceeding threshold limits (e.g., pig meat) to products with higher probability (e.g., bovine animal meat), and by shifting sample collection from the last quarter of the year toward the first three quarters of the year.     

不等概率抽取群单位时样本量的间接计算

讨论了应用设计效应间接计算不等概率抽群的单级整群抽样和二阶段抽样方案样本量的问题,其中包括：所论抽样方案设计效应的估计;估计所论总体的方差,并根据精度要求计算简单随机抽取基本抽样单元时所需的样本量;用设计效应将上述样本量换算成所论抽样方案需要的样本量。