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131.
In the statistical process control literature, there exists several improved quality control charts based on cost-effective sampling schemes, including the ranked set sampling (RSS) and median RSS (MRSS). A generalized cost-effective RSS scheme has been recently introduced for efficiently estimating the population mean, namely varied L RSS (VLRSS). In this article, we propose a new exponentially weighted moving average (EWMA) control chart for monitoring the process mean using VLRSS, named the EWMA-VLRSS chart, under both perfect and imperfect rankings. The EWMA-VLRSS chart encompasses the existing EWMA charts based on RSS and MRSS (named the EWMA-RSS and EWMA-MRSS charts). We use extensive Monte Carlo simulations to compute the run length characteristics of the EWMA-VLRSS chart. The proposed chart is then compared with the existing EWMA charts. It is found that, with either perfect or imperfect rankings, the EWMA-VLRSS chart is more sensitive than the EWMA-RSS and EWMA-MRSS charts in detecting small to large shifts in the process mean. A real dataset is also used to explain the working of the EWMA-VLRSS chart.  相似文献   
132.
儿童的推理能力历来都是考察儿童认知发展的重点。本研究探讨了在多种属性刺激下3~5岁儿童基于重量和声音进行 因果推理的表现。结果发现:4岁和5岁儿童选择正确目标物的准确率显著高于3岁儿童;和同时使用声音与重量判断目标物相 比,儿童在单独使用重量或声音的情况下更容易区分目标物。总之,儿童因果推理能力发展的关键期在4岁并且当任务难度较高 的情况下其因果机制极易受到干扰。  相似文献   
133.
In this article, an agent‐based framework to quantify the seismic resilience of an electric power supply system (EPSS) and the community it serves is presented. Within the framework, the loss and restoration of the EPSS power generation and delivery capacity and of the power demand from the served community are used to assess the electric power deficit during the damage absorption and recovery processes. Damage to the components of the EPSS and of the community‐built environment is evaluated using the seismic fragility functions. The restoration of the community electric power demand is evaluated using the seismic recovery functions. However, the postearthquake EPSS recovery process is modeled using an agent‐based model with two agents, the EPSS Operator and the Community Administrator. The resilience of the EPSS–community system is quantified using direct, EPSS‐related, societal, and community‐related indicators. Parametric studies are carried out to quantify the influence of different seismic hazard scenarios, agent characteristics, and power dispatch strategies on the EPSS–community seismic resilience. The use of the agent‐based modeling framework enabled a rational formulation of the postearthquake recovery phase and highlighted the interaction between the EPSS and the community in the recovery process not quantified in resilience models developed to date. Furthermore, it shows that the resilience of different community sectors can be enhanced by different power dispatch strategies. The proposed agent‐based EPSS–community system resilience quantification framework can be used to develop better community and infrastructure system risk governance policies.  相似文献   
134.
乳制品质量安全是关系消费者健康的重大问题,乳制品质量管控是一项涵盖多环节、多主体的复杂系统工程;而要把质量管控措施落到实处,乳制品产业链的核心企业是关键。针对我国乳制品产业质量管控现状,构建了基于质量价值流动的乳制品全产业链质量管控GERT网络模型,并对"产业链主体未加强质量管控"、"各主体独立加强质量管控"以及"核心企业主导下全产业链质量管控"三种情境进行对比分析。研究表明,核心企业主导下全产业链质量管控具有明显优势;强化乳制品行业质量管控,须从政府层面、企业层面以及消费者层面采取对策,尤其要突出核心企业在此过程中的主导地位。  相似文献   
135.
In this article, Six Sigma zone control charts (SSZCCs) are proposed for world class organizations. The transition probabilities are obtained using the Markov chain approach. The Average Run Length (ARL) values are then presented. The ARL performance of the proposed SSZCCs and the standard Six Sigma control chart (SSCC) without zones or run rules is studied. The ARL performance of these charts is then compared with those of the other standard zone control charts (ZCCs), the modified ZCC and the traditional Shewhart control chart (SCC) with common run rules. As expected, it is shown that the proposed SSZCC outperforms the standard SSCC without zones or run rules for process shifts of any magnitude. When compared to the other standard ZCCs and the Shewhart chart with common run rules, it is observed that the proposed SSZCCs have much higher false alarm rates for smaller shifts and hence they prevent unwanted process disturbances. The application of the proposed SSZCC is illustrated using a real time example.  相似文献   
136.
In the workload control literature, the Load-Oriented Order Release (LOOR) approach has been neglected since its robustness was questioned at the end of the 1990s. This paper revisits LOOR and evaluates whether its performance can be improved in two ways. First, an intermediate pull release mechanism is added to avoid starvation between periodic release events. This mechanism was recently shown to be effective at improving the performance of a state-of-the-art release method known as LUMS COR. Second, an integer linear programming model is used to manage the trade-off between the timing and load balancing functions of order release. The two refinements are assessed using simulations of different shop configurations, which allow us to evaluate robustness. Results demonstrate that the refinements contribute to improving the performance of LOOR such that it can even outperform LUMS COR. Perhaps counter-intuitively, putting more emphasis on load balancing than on the urgency of individual orders is shown to lead to a lower percentage of tardy orders. Overall, the improvements mean that concerns about LOOR’s robustness are no longer valid – it now appears suitable for a wide range of shops found in practice.  相似文献   
137.
企业知识产权包括商标、专利和著作权等,它是企业重要的无形资产。目前,国内大多数企业还不够重视企业的知识产权保护,尤其是专利保护。在研发过程中的专利申请及保护不及时、不到位,导致企业从项目研发到市场占有的整个过程蒙受巨大风险。从知识产权保护角度,探讨了企业研发过程中有关风险的防范措施。  相似文献   
138.
在美国的多元政治体制下,其联邦官僚系统保持着一定程度的自主性。与之同时,又接受着来自国会、总统和社会利益集团等多种政治主体的影响和控制,形成"一仆二主"乃至"一仆多主"的现象。基于美国的民主原则,美国联邦官僚系统必须回应来自政治系统的意愿和利益要求,接受其监督,同时凭借自身的专业技术能力及其他职业性资源,又保持着相对独立性,呈现出美国政治中特有的政治行政关系结构和特征。  相似文献   
139.
We consider the compound Markov binomial risk model. The company controls the amount of dividends paid to the shareholders as well as the capital injections in order to maximize the cumulative expected discounted dividends minus the discounted capital injections and the discounted penalties for deficits prior to ruin. We show that the optimal value function is the unique solution of an HJB equation, and the optimal control strategy is a two-barriers strategy given the current state of the Markov chain. We obtain some properties of the optimal strategy and the optimal condition for ruining the company. We offer a high-efficiency algorithm for obtaining the optimal strategy and the optimal value function. In addition, we also discuss the optimal control problem under a restriction of bounded dividend rates. Numerical results are provided to illustrate the algorithm and the impact of the penalties.  相似文献   
140.
现代社会是权利的社会,也是权利冲突频发的社会。权利之间的冲突缘起于法律规则的模糊性、权利的滥用和权利的交互性。其实质是一种客观存在的事实而非理论预设和逻辑分析的结果。权利冲突可以大致界分为主体间的权利冲突、价值冲突、利益冲突三种类型;权利间的冲突需要借助社会控制模式(个人控制、组织控制、法律控制)并通过价值平衡方法来解决。  相似文献   
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