Modified BLUEs and BLIEs of the location and scale parameters and the population mean using ranked set sampling

Ranked set sampling (RSS) is a sampling procedure that can be used to improve the cost efficiency of selecting sample units of an experiment or a study. In this paper, RSS is considered for estimating the location and scale parameters a and b>0, as well as the population mean from the family F((x?a)/b). Modified best linear unbiased estimators (BLUEs) and best linear invariant estimators (BLIEs) are considered. Numerical computations with different location-scale distributions and different sample sizes are conducted to assess the efficiency of the suggested estimators. It is found that the modified BLIEs are uniformly higher than that of BLUEs for all distributions considered in this study. The modified BLUE and BLIE are more efficient when the underlying distribution is symmetric.     

Point estimation using tail modelling for right skew populations

ABSTRACT

We evaluate the merits of estimators for right-skewed data which are motivated by a distributional assumption for the tail of the population. Our aim is to make a coherent account of estimators of this type already existing in the literature as well as suggesting some modifications, and to compare their performance empirically to other conceivable alternatives. Our results indicate that making use of parametric models to derive the explicit form of estimators can be a fruitful approach for a wide range of right-skewed populations when auxiliary data is not available, especially for small samples.     

The Impact of Information Sharing and Advance Order Information on a Supply Chain with Balanced Ordering

This paper considers a supply chain with one supplier and multiple retailers that face exogenous heterogeneous end‐customer demands, where all parties utilize base‐stock policies. Each retailer is restricted to order once in every order cycle and their orders are replenished in a balanced manner within the cycle. Our study investigates the impact of information sharing and advance order information (AOI) on the supply chain. We find that the supplier benefits from the two mechanisms via two important factors, the information about observed end‐customer demands and the decision on re‐establishing the replenishment sequence. We derive the supplier's optimal sequence for stochastically comparable end‐customer demands with AOI and propose a sequencing rule for the setting with information sharing. Our numerical study examines the cost impacts of two proposed mechanisms on the entire supply chain.     

Cost Allocation in Manufacturing–Remanufacturing Operations

For firms remanufacturing their products, the total life‐cycle costs and revenues from new and remanufactured products determine their profitability. In many firms, manufacturing/sales and remanufacturing/remarketing operations are carried out in different divisions. Each division is responsible for only part of the product's life cycle. Practices regarding transfer pricing across divisions vary significantly among companies, affecting the life‐cycle profit performance of the product. In this research, we identify characteristics of transfer prices that achieve the firm‐wide optimal solution. To this end, we consider a manufacturer who also undertakes remanufacturing operations and we focus on price (quantity) decisions. We determine that a cost allocation mechanism that allocates a portion of the initial production cost to each of the two stages of the product life cycle should be used. We also conclude that cost allocation should be implemented as a fixed cost allocation, where charges to the remanufacturing division should be determined independently of the actual quantity of units remanufactured.     

从语言结构的角度对比中西语言文化

汉语和英语的差别有很多。从语言结构的角度,通过汉英两种语言在词汇结构、单句结构、从句结构、文化原因等方面的对化加以分析。     

情状体对中介语一般过去时习得的影响

情状体对动词一般过去时标记具有一定的影响。笔者对本校英语专业二年级学生的写作作业中收集的记叙文语料的分析结果表明,情状体类型标记顺序为完结动词、达成动词、活动动词和状态动词,与情状体假说的预测基本相符,完结动词和状态动词的情状体标记比率存在显著差异,且情状体对动词一般过去时标记的影响会随着英语学习者水平的提高而逐步减弱。     

炎黄年代及“三皇五帝”历史研究的新进展

最近几年,以炎黄历史和年代研究为核心的“三皇五帝”传说历史研究发生了根本性转折。2003年以前．认为炎黄距今四五千年、考古学的“龙山时代”相当于古史传说的“五帝时代”一直是学界主流认识,而主张炎黄距今六七千年、其历史和文化在考古学的“仰韶时代”仅是极少数学者的认识。2003年王先胜在网络发表《“中国古代文明探源工程”细思量》后开始发生根本性转折,现在“炎黄距今四五千年”已经式微,而“炎黄距今六七千年”已成为学界主流观点和认识。关于中国史前史的轮廓与框架,目前可以通过《中国史前史(“三皇五帝”古史体系)简表》等几个简表来了解与把握。     

大系统观下降解率与均衡价格的联络——资源有界引致的市场逻辑

资源稀缺下的市场定价,由于要素循环是必需的,故市场价格在受上变量和侧变量影响的同时,还受下变量的影响。通过构造劳动力—功能空间图,把表征为下变量的未来因子引入对均衡价格的决定中,并认为当期均衡价格由"未来商品供给和当前商品供给生成的总供给"与"未来商品需求和当前商品需求生成的总需求"联合决定,由此引入影响未来供给的降解率因子。因此,资源稀缺社会里,社会机制的设计和社会法则的提取应放在更大系统内探究。     

Order Progress Information: Improved Dynamic Emergency Ordering Policies

Technologies such as radio‐frequency identification and global positioning systems can provide improved real‐time tracking information for products and replenishment orders along the supply chain. We call this type of visibility order progress information. In this paper, we investigate how order progress information can be used to improve inventory replenishment decisions. To this end, we examine a retailer facing a stochastic lead time for order fulfillment. We characterize a replenishment policy that is based on the classical (Q, R) policy and that allows for releasing emergency orders in response to the order progress information. We show that the optimal structure of this policy is given by a sequence of threshold values dependent on order progress information. In a numerical study we evaluate the cost savings due to this improved replenishment policy.     

基于顾客分类的生鲜农产品二次补货策略

零售商为弥补生鲜农产品新鲜度降低造成的顾客流失,选择在单销售期内二次补货,将新鲜产品和初始订货的非新鲜产品同时销售。但二次补货的新鲜产品会对初始订货产品形成需求挤兑。将顾客划分为三种类型:只购买新鲜产品、只够买折扣产品和两种产品都愿意购买,引入需求挤兑因子的概念,讨论了不同顾客类型下需求挤兑效应对零售商订货决策和利润的影响,并与单次订货策略做比较。结论表明,随着顾客对产品品质和新鲜度要求不断提高,二次补货策略能有效降低订货总量,提升零售商利润水平;不但优化了经济效益,更具有减少产品损耗和节约社会资源、增加消费者福利水平的社会效益。