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61.
明晰学术英语与学术英语写作、学术能力与学术写作能力的概念区别;综述国内外几十年来的学术英语写作能力的培养研究;提出对非英语专业研究生学术英语写作能力的培养模式:以学术阅读带动学术写作能力的提高,以体裁分析理论为基础的互动学习,写作技能训练与研究生专业知识相结合,面授知识与网络自主学习相结合。  相似文献   
62.
机械产品的设计一直注重于市场需求和产品功能的开发,随着科学和技术的发展,环境因素变得越来越重要。 提出一种基于功能一环境一结构分析( FESA)与TRIZ的机械产品创新设计方法,通过分析机械产品结构之间的功能要素 以及功能要素与环境要素的相互作用关系,确定机械产品中存在的问题。建立根原因模型图,寻找结构设计上的不足和 缺陷,利用TRIZ创新理论来实现机械产品的改进创新。通过污水处理系统的创新设计实例验证了该方法的可行性。  相似文献   
63.
本文报告一种金融时间序列预测的信号分析、信息融合与智能计算组合模型,简称FEPA,由针对金融时间序列(FTS)信号分析的经验模态分解(EMD)、用于数据降维的主成分分析(PCA)和用于非线性建模的人工神经网络(ANN)三部分组成。该模型首先应用滑动窗口截取原始金融时间序列最近期数据集,应用EMD分解算法把数据集分解成不同尺度的本征模态函数(IMF),然后通过主成分分析将分解后的数据降维,提取最有信息量的特征;然后将这些特征输入到神经网络进行组合预测。本文提出的组合预测模型FEPA是基于分解-提优-合成的信息融合思想,有效提高了预测可靠性。其创新点在于:1)首次给出了EMD算法的结构化表达,提供了今后融合更多信息的算法接口;2)通过多步长预测输出深入研究EMD分解的有效信息结构;3)通过切换到更细时间框架来处理EMD的端点效应,并探索了两级时间框架下的预测效果;4)给出了金融时间序列组合预测模型的一般性架构,具有可升级性和可扩展性。并且通过滑动窗口EMD使得实证更能切近实际。通过在沪深300股指和澳大利亚股指上的实证,结果表明FEPA预测模型在沪深300股指日线和15分钟线上的预测命中率高达78%和82%,在澳大利亚股指日线上也达到了74%的命中率,经比较,明显高于文献中常见的5种模型。  相似文献   
64.
User information satisfaction (UIS) is important because of its potential effects on MIS department goals, quality of user work life, and extent of voluntary usage of systems. Reliable measurement of UIS is important for providing evaluative information for both researchers and practitioners. This study used 92 managers and executives as subjects to compare the test/retest reliability of a widely used, 13-scale UIS instrument together with four summary questions under experimental and control conditions. The summary questions behaved more reliably than the detailed questions for all groups, perhaps because of problems with scale units and origins and with item heterogeneity. This suggests that researchers need more reliable measures of UIS and that practitioners need to exercise caution when collecting and interpreting UIS scores.  相似文献   
65.
Two related streams of criticism of the analytic hierarchy process (AHP) have not yet been satisfactorily resolved, although both date from the early 1980s. The first relates to ambiguity in the meaning of the relative importance of one criterion as compared to another. The second is concerned with reversals of rank alleged to be possible when new options are introduced in an AHP problem. Both proponents and critics of AHP agree that rank reversals occur, but disagree on the legitimacy of such reversals. This paper shows that there is a necessary correspondence between the manner in which criteria importances are interpreted and computed and the manner in which the weights of the options under each criterion are normalized. In general, if this relationship is ignored, incorrect weights are generated for options under consideration regardless of whether new options are added or deleted. A rank reversal on the addition of an option is merely symptomatic of this fact, and such reversals do not occur when the correspondence condition is met.  相似文献   
66.
The metaphor of the glass ceiling helps one to focus on the often invisible barriers qualified women have to deal with, in order to access to the highest professional positions. This article presents the set of contributions, which clarifies the evolution of this phenomenon in various professions and in various countries. It gives one a more dynamic and less linear view on the top job feminization throughout the 20th century.  相似文献   
67.
Women with diplomas, authority, power, in the professions, in top jobs… Nowadays, since demands have taken shape around the concepts of “parities” or quotas, the phases in the process whereby women have gained access to top positions in employment risk being overlooked. This process stretches out over a long time, even though Western European countries have passed through successive phases at about the same time. The years 1880, 1920, 1970 and 2000 stand out like landmarks in this conquest starting out from equal access to education and continuing through the slow mixing of the two sexes in various types of jobs, medical, technical, legal, military or political. Till the last decades of the 20th century, feminists (men as well as women) fought for these advances despite the scorn of those men and women who wanted to see women confined to the jobs “fit for them”, in particular in education and care-giving.  相似文献   
68.
Diversification gains in mean-variance efficiency derived from including real estate in financial asset portfolios are examined. Optimal financial and mixed-asset portfolios were generated by selecting from an investment universe including several distinct financial and real estate media. Deficiencies of previous studies were overcome by employing data with improved representativeness and comparability. The efficient mixed-asset portfolios dominated the efficient financial asset portfolios implying that purely financial asset diversification is inefficient. The optimal mixed-asset portfolio prescribed that approximately two-thirds of the investment wealth be allocated to real estate and one-third to the financial media.  相似文献   
69.
Water, and Sanitation projects play an important role in alleviating water‐related poverty in developing countries. There are several methodologies that will not only assess the performance of these projects but will also help to better identify the problem and its characteristics, and to improve the efficiency of the investment. The Water Poverty Index is one of them. It is a very useful tool that helps to measure water stress at the household level in a holistic way, and to identify priorities. It is important, however, to complement it with a Cost‐Benefit Analysis that will take into account the costs of the project. A case study in Northern Colombia illustrates this point.  相似文献   
70.
This study constructs a simultaneous confidence region for two combinations of coefficients of linear models and their ratios based on the concept of generalized pivotal quantities. Many biological studies, such as those on genetics, assessment of drug effectiveness, and health economics, are interested in a comparison of several dose groups with a placebo group and the group ratios. The Bonferroni correction and the plug-in method based on the multivariate-t distribution have been proposed for the simultaneous region estimation. However, the two methods are asymptotic procedures, and their performance in finite sample sizes has not been thoroughly investigated. Based on the concept of generalized pivotal quantity, we propose a Bonferroni correction procedure and a generalized variable (GV) procedure to construct the simultaneous confidence regions. To address a genetic concern of the dominance ratio, we conduct a simulation study to empirically investigate the probability coverage and expected length of the methods for various combinations of sample sizes and values of the dominance ratio. The simulation results demonstrate that the simultaneous confidence region based on the GV procedure provides sufficient coverage probability and reasonable expected length. Thus, it can be recommended in practice. Numerical examples using published data sets illustrate the proposed methods.  相似文献   
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