China＇s Penetration of the Korean Market： Stylized Facts and Welfare Effect

China＇s penetration of the world market has been impressive. This paper uses highly disaggregated Korean import data （from 1992 to 2008） to examine China ＇s penetration of the Korean market in the context of the composition of value （the extensive and intensive margins） and the product type （homogeneous and differentiated） in trade. The increase in Chinese imports has been attributed to the rapid increase in the import of new products （the extensive margin） and of existing products （the intensive margin）. However, the growth rate of new products decelerated in the 2000s. The growth in the intensive margin was due to quantity, not price. Chinese imports to Korea did not improve over the period in terms of quality. Although Chinese products became cheaper, they were more differentiated over time. Welfare gains were realized through the expanded introduction of new products from China. However, much of the gains from Korea＇s Chinese product import boom were realized in earlier years （1992 -2000） because even though imported products became more differentiated, the increase in the extensive margin was lower in more recent years （2001- 2008）.     

Logistic model-based forecast of sales and generation of obsolete computers in the U.S.

Our goal is to characterize future trends in the generation of obsolete computers in the U.S. Starting from historical sales data on new computers and assuming a plausible first lifespan distribution, we extrapolate the historical sales trend to the future using a logistic model. The major challenge is that the personal computer is still in an early stage of its technology adoption life cycle and thus early for statistical fits to yield a reasonable estimation of carrying capacity (or saturation adoption level). Our approach is to use a bounding analysis which characterizes a range based on plausible upper and lower bounds on the future carrying capacity (1.3 and 1.0 computers per capita respectively). These lower and upper bounds yield a generation of 92 and 107 million obsolete computers in 2020 respectively. The growth rates of adoption over the next decade are very different for lower versus upper bound, however by 2020 the adoption will be at most 8% away from the long-term carrying capacity in both cases. Assuming computer adoption follows logistic behavior we assert that the saturation level of generation of obsolete computers is not much more than a decade away. The current recycling level of computers is 65 million units, thus if the U.S. expects to recycle computers domestically significant growth of recycling facilities will be required. Note however that this analysis does not address how long obsolete computers are stored nor the distribution of obsolete computers to reuse, recycling, landfill options. This is an important issue to resolve in future work.     

对数相位板波前编码景深延拓系统研究

波前编码技术结合光学成像和数字信号处理,可以使系统的光学传递函数或点扩散函数对离焦不敏感,因而可以延拓光学成像系统的景深。文章以系统的点扩散函数对离焦不敏感为条件导出可以实现景深延拓的对数光瞳函数,这为目前波前编码技术中常用的3次相位调制函数提供了对照对象,为波前编码景深延拓技术的研究开辟了另一条途径。     

浅谈钻井液管理控制对提高机械钻速的贡献

机械钻速是影响钻井速度的主要因素之一,而钻井液在提高机械钻速方面发挥着愈来愈大的作用。本文就钻井液对提高机械钻速的贡献做讨论,分析钻井液对机械钻速的影响,并介绍了大庆油田的钻井液使用概况以及国外先进的钻井液技术。     

某工程深基坑边坡支护设计与施工

基坑边坡支护及加固是地下结构工程施工中常见施工方案,也特别容易出现安全事故,文章对一个已经安全施工的基坑工程的支护方法和采取的措施进行了介绍.     

Post-Reform Market-Order Execution Quality: Multidimensional Comparisons Across Market Centers

We use market‐order data to determine execution quality on the NYSE, four regional stock exchanges, and the Nasdaq InterMarket. We examine a sample period after the reduction in the minimum price variation and after the SEC imposed new order‐handling rules, and analyze dimensions of execution quality in addition to trade prices. We find that in the postreform environment, the NYSE offers execution prices that are more favorable to the investor. However, the regional exchanges and the InterMarket offer executions that are faster and that more frequently allow investors to execute orders with sizes exceeding the quoted depth at the quoted price.     

Estimation of innovation diffusion models with application to a consumer durable

A class of birth processes having a variety of practical applications in penetration of new services and products is considered. Typically, statistical inferences on these models are performed by means of simple error structures placed on the deterministic analogs of the underlying stochastic processes. Motivated by the poor performance of conventional estimation methods, the problem of estimating the parameters of these models is readdressed. We develop necessary formulae for performing the maximum likelihood estimation and weighted least squares estimation methods, and demonstrate their superiority through analyses of some real data and simulation studies.     

加深对英语言语个体性、多变性的认识,提高听音理解的能力

言语是人们进行交际活动的过程或产物。人们在用言语进行交际活动过程中,言语 通常带着一定个体主观反映和表述客观现实的印记,即具有个体性和多变性。它往往不会偏离该 语言的标准发音规则和语法规则,而且在同一情景下,在描述或表达同一事件时,会因个体的知 识水平、生活经历、职业、地位、观点、情绪等不同显示出言语表述方式和表现风格上的差异。 英语言语的这种个体性、多变性现象是影响中国学生英语听力理解的主要因素之一。加深对英语 言语个体性和多变性的表现规律的认识,有助于提高听觉感知、理解英语的能力。     

张双楼煤矿底板采动效应应力解析与数值模拟对比研究

为了评价张双楼煤矿9煤的底板突水,根据-350m和-500m两个水平的工作面的煤层底板地质特征,运用快速拉格朗日法对底板的采动效应进行了数值模拟,分析了采动过程中底板岩体应力场、塑性区的分布,通过建立采场底板破坏深度应力解析模型求得底板破坏深度值,认为底板破坏深度值介于两种方法得出值之间更为合理,研究结果为底板水害防治提供了理论依据。     

基于深度融合的酒店管理专业校企合作模式创新研究

当前,许多高职院校在校企合作方面出现的一些问题是由于只做到了过程上的衔接,忽视了对专业、酒店、学生三方利益的考虑。深度融合模式的前提是目标的融合,利益的融合。深度融合的基础应该建立在合作成果的三方共享上,专业寻求发展,酒店寻求盈利,学生寻求平台和职业发展。构建深度融合体系的关键因素是目标融合、资源融合和过程融合。