课外虚拟学习社区的推广应用

虚拟学习社区作为一种新的网络学习支撑平台越来越被人们所熟悉和接受。文章针对目前常规虚拟学习社区的不足,提出了利用腾讯QQ作为辅助教学平台,阐述了由教师主导的课外虚拟学习社区的建立、功能与运行效果。通过教学实践与调查研究,得出课外虚拟学习社区有效的促进师生交流,拓展学生视野,增强学生协作意识,满足学生的个性化学习。课外虚拟学习社区作为课堂教学的一种辅助模式,值得推广应用。     

The roots of inequality: estimating inequality of opportunity from regression trees and forests*

We propose the use of machine learning methods to estimate inequality of opportunity and to illustrate that regression trees and forests represent a substantial improvement over existing approaches: they reduce the risk of ad hoc model selection and trade off upward and downward bias in inequality of opportunity estimates. The advantages of regression trees and forests are illustrated by an empirical application for a cross-section of 31 European countries. We show that arbitrary model selection might lead to significant biases in inequality of opportunity estimates relative to our preferred method. These biases are reflected in both point estimates and country rankings.     

Technology adoption and accumulation in a vintage-capital model

We present a model of capital accumulation and technology adoption in a vintage-capital framework. The model is an infinite-horizon/infinite-dimensional optimal control model: the firm employs a continuum of technologies (a continuum of heterogeneous capital goods). Capital goods are technology specific, their technology is related to vintage and technology progress. The entrepreneur maximizes the profits obtained by employing a continuum of technologies under the assumption of constant returns to scale and bearing adjustment costs for gross investments. The diffusion of a new technology is established by allowing the entrepreneur to invest in vintage capital goods.     

A review of experience curve analyses for energy demand technologies

Transitioning towards a sustainable energy system requires the large-scale introduction of novel energy demand and supply technologies. Such novel technologies are often expensive at the point of their market introduction but eventually become cheaper due to technological learning. In order to quantify potentials for price and cost decline, the experience curve approach has been extensively applied to renewable and non-renewable energy supply technologies. However, its application to energy demand technologies is far less frequent. Here, we provide the first comprehensive review of experience curve analyses for energy demand technologies. We find a widespread trend towards declining prices and costs at an average learning rate of 18 ± 9%. This finding is consistent with the results for energy supply technologies and for manufacturing in general. Learning rates for individual energy demand technologies are symmetrically distributed around the arithmetic mean of the data sample. Absolute variation of learning rates within individual technology clusters of 7 ± 4%-points and between technology clusters of 7 ± 5%-points both contribute to the overall variability of learning rates. Our results show that technological learning is as important for energy demand technologies as it is for energy supply technologies. Applying the experience curve approach to forecast technology costs involves, however, unresolved uncertainties, as we demonstrate in a case study for the micro-cogeneration technology.     

新疆高校少数民族大学生预科汉语学习状况调查分析

在预科汉语学习中,由于少数民族大学生自身汉语水平、对预科汉语学习的认识以及高校在预科汉语课程设置、师资队伍、教材、教学方法等方面的一些不足,制约了少数民族大学生的预科汉语学习。若要解决少数民族大学生预科汉语学习中存在的问题,就应从完善预科汉语课程设置、抓好师资队伍建设、做好预科汉语教材建设、提升教学理念、改进教学方法等方面着手,进一步提高少数民族大学生预科汉语学习的积极性。     

Excessive Volatility is Also a Feature of Individual Level Forecasts

The excessive volatility of prices in financial markets is one of the most pressing puzzles in social science. It has led many to question economic theory, which attributes beneficial effects to markets in the allocation of risks and the aggregation of information. In exploring its causes, we investigated to what extent excessive volatility can be observed at the individual level. Economists claim that securities prices are forecasts of future outcomes. Here, we report on a simple experiment in which participants were rewarded to make the most accurate possible forecast of a canonical financial time series. We discovered excessive volatility in individual-level forecasts, paralleling the finding at the market level. Assuming that participants updated their beliefs based on reinforcement learning, we show that excess volatility emerged because of a combination of three factors. First, we found that submitted forecasts were noisy perturbations of participants’ revealed beliefs. Second, beliefs were updated using a prediction error based on submitted forecast rather than revealed past beliefs. Third, in updating beliefs, participants maladaptively decreased learning speed with prediction risk. Our results reveal formerly undocumented features in individual-level forecasting that may be critical to understand the inherent instability of financial markets and inform regulatory policy.     

高职非英语专业新生课堂学习策略的使用情况调查

基于Oxford提出外语学习策略分类,本文采用问卷调查和访谈的方式对高职非英语专业新生的课堂学习策略使用情况进行调查和分析。通过数据分析,研究结果表明:受试学习策略的使用频率不高,最常使用的学习策略是补偿策略,最不常使用的是记忆策略等。     

浅谈多媒体和网络技术在大学英语自主学习中的作用

在我国推行新一轮大学英语课程改革和高校扩招的大背景下,提高学生的自主学习能力的要求越来越迫切。简要介绍了"自主学习"理论,描述了我国大学生自主学习的现状,并且详细阐述了多媒体和网络技术在大学英语自主学习中的作用。     

会计人员终身学习的人文环境研究

随着世界经济的发展和我国社会主义市场经济的发展,科学技术和创新理论不断发展,终身教育、终身学习已成为社会发展的客观要求,许多国家都以立法的形式将终身学习纳入法治的轨道,中国改革开放30年来,社会经济也得到突飞猛进的发展,但是尚未建立有效的适合于会计人员终身学习的人文环境。文章从以人为本、良好的秩序、终身学习的科学理念、社会和谐、爱岗敬业精神、社会公平与平等方面研究会计人员终身学习人文环境建设,认为只有创建良好的人文环境,才能留住人才、用好人才,满足社会和经济发展的需要。     

中外高校机构编制管理的比较及启示

我国高校机构编制管理缺乏有力的外部监督和内部约束;而以美国为代表的国外高校则在“行政-学术”二元权力架构的安排、管理机构的设置、人员编制的分类与控制等方面形成了一整套科学的做法。借鉴其经验,应通过国家或地方行政立法来规范高校机构编制管理,将机构编制管理绩效纳入对高校的考核范围,要在精简机构的同时建立健全高校的学术权力机构,各地教育行政部门也要建立起一套完善的实施监管的技术性程序。