The classical EPQ model has been used for a long ti me and is widely accepted and implemented. Nevertheless, the analysis for finding an economic lot size has based on a number of unrealistic assumptions. A common unr...The classical EPQ model has been used for a long ti me and is widely accepted and implemented. Nevertheless, the analysis for finding an economic lot size has based on a number of unrealistic assumptions. A common unrealistic assumption in using EPQ is that all units produced are of good quali ty. The classical EPQ model shows that the optimal lot size will generate minimum ma nufacturing cost, thus producing minimum setup cost and inventory cost. However, this is only true if all products manufactured in the process are assumed to be of good quality (i.e. all products are within the specification limits). In rea lity this is not the case, therefore, it is necessary to consider the cost of im perfect quality items, because this cost can influence the economic lot size. Ma ny studies and recent papers have indicated that there is a significant relation ship between economic production lot size and process/product quality. However, their models included either the imperfect quality items (not necessarily de fective) which are to be sold at a discounted price or defective items which can be reworked or rejected. The aim of this paper is to provide a framework to integrate three different sit uations (discounted pricing/rework/reject) into a single model. 100% inspection is performed in order to distinguish the amount of good quality items, imper fect quality items and defective items in each lot. In this paper, a mathematica l model is developed, and a numerical example is presented to illustrate the sol ution procedures. It is found that the economic production lot size tends to inc rease as the average percentage of imperfect quality items and defectives (rejec ted items) increases.展开更多
目的编制脑卒中患者照顾者倦怠量表(burnout scale of stroke patients’caregivers,BSSPCs),并进行信效度检验,为脑卒中患者照顾者倦怠测评提供工具。方法在前期构建的脑卒中患者主要照顾者倦怠概念框架及文献分析的基础上,借鉴职业倦...目的编制脑卒中患者照顾者倦怠量表(burnout scale of stroke patients’caregivers,BSSPCs),并进行信效度检验,为脑卒中患者照顾者倦怠测评提供工具。方法在前期构建的脑卒中患者主要照顾者倦怠概念框架及文献分析的基础上,借鉴职业倦怠量表,构建条目池;通过专家咨询法及预调查,形成BSSPCs初稿;2022年7月至2023年1月,采用便利抽样法选取银川市和吴忠市5所医院康复科收治的506名脑卒中患者照顾者进行调查,应用经典测量理论(classical test theory,CTT)和项目反应理论(item response theory,IRT)对量表进行测量学评价。结果CTT结果提示存在6个条目不满足统计学要求,IRT结果显示共6个条目不符合难度、区分度或信息量的筛选标准,最终形成的BSSPCs包括角色倦怠、生理倦怠、心理倦怠和社交倦怠4个维度共24个条目。结论BSSPCs的编制过程严谨,各项心理学测量指标比较满意,为量化照顾者倦怠和开展后续研究提供了工具支持。展开更多
文摘The classical EPQ model has been used for a long ti me and is widely accepted and implemented. Nevertheless, the analysis for finding an economic lot size has based on a number of unrealistic assumptions. A common unrealistic assumption in using EPQ is that all units produced are of good quali ty. The classical EPQ model shows that the optimal lot size will generate minimum ma nufacturing cost, thus producing minimum setup cost and inventory cost. However, this is only true if all products manufactured in the process are assumed to be of good quality (i.e. all products are within the specification limits). In rea lity this is not the case, therefore, it is necessary to consider the cost of im perfect quality items, because this cost can influence the economic lot size. Ma ny studies and recent papers have indicated that there is a significant relation ship between economic production lot size and process/product quality. However, their models included either the imperfect quality items (not necessarily de fective) which are to be sold at a discounted price or defective items which can be reworked or rejected. The aim of this paper is to provide a framework to integrate three different sit uations (discounted pricing/rework/reject) into a single model. 100% inspection is performed in order to distinguish the amount of good quality items, imper fect quality items and defective items in each lot. In this paper, a mathematica l model is developed, and a numerical example is presented to illustrate the sol ution procedures. It is found that the economic production lot size tends to inc rease as the average percentage of imperfect quality items and defectives (rejec ted items) increases.
文摘目的编制脑卒中患者照顾者倦怠量表(burnout scale of stroke patients’caregivers,BSSPCs),并进行信效度检验,为脑卒中患者照顾者倦怠测评提供工具。方法在前期构建的脑卒中患者主要照顾者倦怠概念框架及文献分析的基础上,借鉴职业倦怠量表,构建条目池;通过专家咨询法及预调查,形成BSSPCs初稿;2022年7月至2023年1月,采用便利抽样法选取银川市和吴忠市5所医院康复科收治的506名脑卒中患者照顾者进行调查,应用经典测量理论(classical test theory,CTT)和项目反应理论(item response theory,IRT)对量表进行测量学评价。结果CTT结果提示存在6个条目不满足统计学要求,IRT结果显示共6个条目不符合难度、区分度或信息量的筛选标准,最终形成的BSSPCs包括角色倦怠、生理倦怠、心理倦怠和社交倦怠4个维度共24个条目。结论BSSPCs的编制过程严谨,各项心理学测量指标比较满意,为量化照顾者倦怠和开展后续研究提供了工具支持。
