工程制图课程体系和教学方法改革的思路与实践

在阐述工程制图课程重要和特殊地位的基础上 ,概括指出了目前我国工程制图课程改革的三种教学模式 ,并列举了国外部分院校课程改革的实例 ,总结出教改共识。在明确课程改革基本思想的前提下 ,具体提出课程改革的总体思路和实践过程 :整合课程内容 ,形成新的课程体系 ,构建基础平台 ;改革教学手段 ,更新教学方法 ,保证教学质量 ,提高教学效率     

《读书人是幸福人》说课设计

说课,是检验教师教学基本功的手段之一,它不同于一般的发言稿和课堂教学,它要求说者比较系统地介绍自己的教学设计及其理论依据(包括大纲依据、课程标准依据、教学法依据、教育学和心理学依据等),而不是宣讲教案,也不是浓缩课堂。它的核心在于说理,在于说清为什么要这样教,用什么理论来支持教学,说课的重点在于教学重点和教学难点的突破上。说案不同于教案。     

Analytical approximations for iterated bootstrap confidence intervals

Standard algorithms for the construction of iterated bootstrap confidence intervals are computationally very demanding, requiring nested levels of bootstrap resampling. We propose an alternative approach to constructing double bootstrap confidence intervals that involves replacing the inner level of resampling by an analytical approximation. This approximation is based on saddlepoint methods and a tail probability approximation of DiCiccio and Martin (1991). Our technique significantly reduces the computational expense of iterated bootstrap calculations. A formal algorithm for the construction of our approximate iterated bootstrap confidence intervals is presented, and some crucial practical issues arising in its implementation are discussed. Our procedure is illustrated in the case of constructing confidence intervals for ratios of means using both real and simulated data. We repeat an experiment of Schenker (1985) involving the construction of bootstrap confidence intervals for a variance and demonstrate that our technique makes feasible the construction of accurate bootstrap confidence intervals in that context. Finally, we investigate the use of our technique in a more complex setting, that of constructing confidence intervals for a correlation coefficient.     

CO_2增加与未来气温变化

近几十年来．由于人类活动导致大气中ＣＯ２含量呈明显上升趋势，预计到下世纪中叶ＣＯ２浓度将达到４５０ｐｐｍ左右，下世纪末，将达到工业革命前的两倍，各种数值模式表明，届时全球气温将升高１．５－４．５℃。     

最优验血方法的判定

本文对Ｎ个人验血的检验方法进行研究．得到如下结果：（１）设普查对象的阳性概率为ｐ，对当时，采用分组检验最优；当ｐ≥０．３０７８时，采用单个检验最优、（２）当采用分组检验时，分组人数或时，检验次数最少．     

治疗腰痛的气功功法和功理

本文扼要论述腰痛治疗三个层次的气功功法和功理.     

Sample selection in radiocarbon dating

Archaeologists working on the island of O'ahu, Hawai'i, use radiocarbon dating of samples of organic matter found trapped in fish-pond sediments to help them to learn about the chronology of the construction and use of the aquicultural systems created by the Polynesians. At one particular site, Loko Kuwili, 25 organic samples were obtained and funds were available to date an initial nine. However, on calibration to the calendar scale, the radiocarbon determinations provided date estimates that had very large variances. As a result, major issues of chronology remained unresolved and the archaeologists were faced with the prospect of another expensive programme of radiocarbon dating. This paper presents results of research that tackles the problems associated with selecting samples from those which are still available. Building on considerable recent research that utilizes Markov chain Monte Carlo methods to aid archaeologists in their radiocarbon calibration and interpretation, we adopt the standard Bayesian framework of risk functions, which allows us to assess the optimal samples to be sent for dating. Although rather computer intensive, our algorithms are simple to implement within the Bayesian radiocarbon framework that is already in place and produce results that are capable of direct interpretation by the archaeologists. By dating just three more samples from Loko Kuwili the expected variance on the date of greatest interest could be substantially reduced.     

宏观连续交通流数值模拟

应用交通流宏观连续模型,模拟上下游信号灯作异步周期变化的协调信号灯路段的交通流动,经数值计算比较,选择改进Ｍｕｒｍａｎ格式求解．结果表明：改进Ｍｕｒｍａｎ格式能准确捕捉交通流中无振荡“激波”位置．     

The efficacy of using judgmental versus quantitative forecasting methods in practice

In an era where forecasts drive entire supply chains forecasting is seen as an increasingly critical organizational capability. However, business forecasting continues to rely on judgmental methods despite large advancements in information technology and quantitative method capability, prompting calls for research to help understand the reasons behind this practice. Our study is designed to contribute to this knowledge by profiling differences between firms identified as primary users of either judgmental or quantitative forecasting methods. Relying on survey data from 240 firms we statistically analyzed differences between these categories of users based on a range of organizational and forecasting issues. Our study finds large differences in forecast error rates between the two groups, with users of quantitative methods significantly outperforming users of judgmental methods. The former are found to be equally prevalent regardless of industry, firm size, and product positioning strategy, documenting the benefits of quantitative method use in a variety of settings. By contrast, the latter are found to have significantly lower access to quantifiable data and to use information and technology to a lesser degree.