工程图学教学改革的探索

工程图学是一门以图形为研究对象,用图形来表达设计思想的一门学科,在我国各院校开设已有多年的历史,其教学内容、教学方法、教学手段等自成体系。但随着每年新生人数不断增加,而师资队伍不能同步的发展,课时精简而教学要求不能降低。其次随着计算机技术的发展,信息技术与其他学科教学的结合等诸多因素,使工程图学的传统教学面临严峻挑战,为了应对挑战,需要分析在图学传统教学中存在的问题,解决的方法及措施,建立适应新形势下的现代工程图学的教学模式。     

从“师夷长技”到提倡“格致之学”——论近代前期的科学思潮

近代中国人学习和传播西方近代科学技术的历程是不断深化的.最初是经世派提出"师夷长技"口号;接着洋务派继承这一口号,并掀起一个引进西方技术的实际运动;稍后,部分先进分子认识到西方船坚炮利的背后是发达的格致之学,从而将国人的科技观由感性器物层面发展到"理"与"学"的理论层面.但在整个近代前期,中国人都是在"西学中源"说和"中体西用"论框架内提倡学习西方科技的.这表明人们尚没有从根本上认识近代科学及科学文化的性质,近代科学思潮尚处于萌发和初级阶段.     

我国柯尔克孜族自治地方民族关系及问题

克孜勒苏柯尔克孜自治州是我国惟一一个以柯尔克孜族命名的自治州。在这个柯族自治地方生活着10个民族的居民。维吾尔族人口最多,在农区影响也最大;柯族在牧区占主导地位;汉族则主要在城镇发生影响。各民族和睦共处是主流,充分体现了“谁也离不开谁”。但由于种种原因。这里也存在着一些妨碍民族团结的因素。     

The covariance structure of sequential forecasts obtained by regression analysis

A method is presented for evaluating the covariance matrix of a set of sequential forecasts obtained by regression analysis. The matrix can be used to derive the relation between the variance of the forecasts on the one hand, and the lead times between the forecasting time and the time at which the forecasted variables are realized, on the other hand. The determination of this relation is important whenever the optimal frequency of forecasting must be determined.     

Spectral properties of the concurrent and forecasting seasonal linear filters of the X-11-ARIMA method

This study analyzes the properties of the linear filters of the X-11-ARIMA seasonal adjustment method applied for current seasonal adjustment. It provides the general formula for the combined weights that result from the ARIMA model extrapolation filters with the X-11 seasonal-adjustment filters. The three cases studied correspond to the three ARIMA models automatically tested by the X-11-ARIMA program, namely, (0, 1, 1)(0, 1, 1), (0, 2, 2)(0, 1, 1), and (2, 1. 2)(0, 1,1). The parameter values chosen reflect different degrees of flexibility of the trend-cycle and seasonal components. It is shown that the X-11-ARIMA linear filters for current seasonal adjustment are very flexible; they change with both the ARIMA extrapolation model and its parameter values, contrary to those of the X-11 program, which are fixed for a given set of options.     

海南旅游业的定位及走向

使用数量分析的方法,针对海南旅游业在过去10年发展中所存在的问题,从资源、市场、产品和促销形象四个方面对其开发思路和趋向做出了重新定位——生态示范性休闲度假地,以实现海南旅游业的可持续发展。     

浙江民营影视公司发展的现状与趋势

改革开放以来,浙江民营资本开始进入影视传媒业,尤其是21世纪以来迅速崛起。民营影视公司数量快速增大,达到500多家,竞争力不断增强,演绎出自己的发展特点,形成了影视浙军态势。     

Analysis on China's Labor Supply and Demand Trend for a Long-term

The paper take Leslie method to forecast China's total population and its age distribution structure from 2015 to 2050,and then predict the total labor supply of the working-age population,estimate the total demand for labor according to the employment elasticity of the economic growth,calculated the gap between labor supply and demand.The results show that both the labor supply and demand showed a decreasing trend,but the supply reduced faster than demand,after 2015,the labor market appears shortage,the gap between supply and demand will exist for a long time and have a tendency to expand.Facing of the new situation and new problems of the labor market,we recommend some corresponding policy.     

Trend inflation,the labor market wedge,and the non-vertical Phillips curve

Recent developments in macroeconomics resurrect the view that welfare costs of inflation arise because the latter acts as a tax on money balances. Empirical contributions show that wage re-negotiations take place while expiring contracts are still in place. Bringing these seemingly unrelated aspects together in a stylized general equilibrium model, we find a disciplining effect of a positive inflation target on the wage markup and identify a long-term trade-off between inflation and output. This has important policy implications, ranging from the opportunity of revising the target in response to shocks, to the possibility of exploiting inflation as a tool to increase tax revenues via its employment-enhancing effect.     

Using Entropic Tilting to Combine BVAR Forecasts With External Nowcasts

This article shows entropic tilting to be a flexible and powerful tool for combining medium-term forecasts from BVARs with short-term forecasts from other sources (nowcasts from either surveys or other models). Tilting systematically improves the accuracy of both point and density forecasts, and tilting the BVAR forecasts based on nowcast means and variances yields slightly greater gains in density accuracy than does just tilting based on the nowcast means. Hence, entropic tilting can offer—more so for persistent variables than not-persistent variables—some benefits for accurately estimating the uncertainty of multi-step forecasts that incorporate nowcast information.