Optimal lot sizing under continuous price decrease

An important characteristic of high-tech industries is decreasing component prices over time. In the personal computer industry, some component prices decline at a rate of 1% per week. This paper develops an inventory model for products experiencing continuous decrease in unit price. We develop an accurate closed-form approximate solution to the model. Our results indicate that declining prices lead to substantial decrease in the optimal cycle time and much frequent ordering. This explains the heavy emphasis on just-in-time inventory management practiced by successful companies in high-tech industries. While previous models attributed the success of just-in-time policies to reduced holding cost and improved quality, under declining prices a substantial source of savings becomes lower costs of raw materials which is significant part of cost in these industries. We illustrate the results of the model with a numerical example and perform sensitivity analysis.     

A Two-dimensional Heat Transfer Model for Atmosphere-land System in the Lake-dominated Alaskan Arctic

1 Introduction Shallow tundra lakes are one of the dominating landscape features in the Alaskan Arctic. They typically cover 20% of the total area of the North Slope of Alaska, and up to about 40% in the coastal plain [1,2]. Many lakes are, in their entirety or in part, shallower than the maximum annual ice thickness, consequently, some ice freezes completely to the lake bottom, nevertheless, large areas of water are deeper than the maximum ice thickness and the ice remains afloat througho…     

服饰时尚中的文化变迁：以牛仔服与唐装为例

牛仔服伴随着改革开放向西方学习的思潮而来,唐装则复兴于繁荣的新世纪之初,本文以“牛仔服”和“唐装”的流行为研究对象,通过探寻其流行原因,来揭示服饰时尚中的文化变迁,并由此展现当今时代多元文化———传统的和现代的、全球的和本土的并存交融的形貌。     

倪瓒逸民遗民心态变化论

本文从对逸民遗民的界定入手,研究了身处元末明初的倪瓒心态及思想的变化,从而廓清了倪瓒在元明易祚之际逸民遗民身份及心理变化。指出倪瓒的这一思想嬗变对于后来明清之际的一些遗民画家对倪瓒传承中的一种文化认同感来说,显得尤为重要。     

基于RS和GIS的龙口市居民地动态变化研究

选择Landsat 1986.6和2002.6两个时期的TM影像,经过多波段彩色合成处理,在分析居民地等多种地物的光谱特征及谱间特征的基础上,建立了居民地信息提取的光谱模型,提取并制作了两个时段的居民地分布图.在此基础上,简要分析了胶东半岛龙口市近20年来居民地动态变化的特点.     

Unexpected but authentic use of an ethnically–marked dialect

Recent work on language crossing in the U.S. has examined the temporary appropriation of African American Vernacular English by white youth in an effort to participate in the current popularity and prestige of hip–hop culture, or in order to highlight racial boundaries. While such verbal behavior probably encompasses most white use of AAVE, it is not the only way in which whites (or other non–blacks) can use the variety. This paper presents a case study of the language of a 23 year old white female who makes consistent use of many distinctive linguistic features associated with AAVE. I argue that the interaction of ideologies of race, class, localness and language allow her to be considered an ingroup member despite her biographical race. This suggests that there is a tension between academic linguistic theory and actual speaker practice in assigning authenticity to individuals, and I conclude that language ideologies and other forms of qualitative evidence should be taken into account by sociolinguists looking at the link between language and race.     

新时期俄语社会政治词汇中一些词语的转义

文章通过大量的报刊中的实例,阐述俄语中的一些社会政治词语的转义用法,揭示了当今俄语在社会政治词语领域的变化。这对改善现今高校俄语专业的教学,更好地用俄语与俄罗斯人交际会起到促进作用。     

我国农地制度变迁的历史考察及绩效分析

有什么样的农地制度就会产生什么样的制度绩效。建国后我国农地制度发生了若干次大的变动,其中,有的是强制性制度变迁,有的是诱致性制度变迁,总体上看,诱致性制度变迁一般都取得了较优的绩效,如家庭联产承包责任制。但由于制度的边际效用是递减的,因此,家庭联产承包责任制不可能是我国农地制度变迁的最后归宿,必将继续发生变动,并很有可能最终被符合市场经济原则的资本雇佣土地的制度所取代。     

论语文教师的角色定位

语文教育所面临的问题和改革的任务 ,对语文教师的角色内涵提出了新的要求。语文教师转变课堂教学观念 ,树立崭新的语文课程性质观 ,并担当好教学的设计者、学习的促进者、终身学习者和研究者的角色 ,是中小学语文教育走出“少慢差费”困境的一个关键     

模糊语言的独特功能

本文对模糊语言的独特功能从日常生活、文学作品、科学医学三方面进行了探讨 ,从而阐明在自然语言中 ,模糊语言是绝对的、普遍的。语言的模糊性缘于客观事物本身的模糊性及人们对客观世界认识的不确定性。