Do children spend too much time in schools? Evidence from a longer school year in Indonesia     

《Economics of Education Review》2014

I examine the effects of a longer school year in Indonesia on grade repetition, educational attainment, employability, and earnings. I exploit an arbitrary rule that assigned students to a longer school year in Indonesia in 1978–1979, which fits a fuzzy regression discontinuity design. I find the longer school year decreases the probability of grade repetition and increases educational attainment; it also increases the probability of working in formal sectors and wages later in life. These results suggest the length of school years in Indonesia is not too long.  相似文献   

品牌生态位测度及其评价方法研究   总被引：17，自引：0，他引：17  

王兴元 《预测》2006,25(5):60-64,80

借鉴生态学原理，对品牌生态位的涵义进行了初探，建立了品牌生态位宽度及重叠度的计算公式，提出了品牌生态位适合度评价的函数法、模糊评价法、适合度复合系数法以及基于同类标杆案例品牌贴近度的品牌生态位适合度评价模型。给出了一个实际应用案例，针对案例中的四个品牌，分别计算了目标品牌、竞争品牌以及标杆品牌的品牌生态位宽度、重叠度。利用综合评价模型对该目标品牌的适合度进行了分析与评价。  相似文献   

细长轴车削动特性的研究   总被引：9，自引：0，他引：9  

黄跃华  张景勘  李德滋 《科技通报》2001,17(4):41-45,49

对细长轴车削的动特性进行了分析、试验和研究，为保证细长轴车削的稳定性以提高加工质量，提出了转速与进量的合理计算公式，计算与实验结果基本一致。  相似文献   

公法线长度测量的应用     

解同信  刘金华 《北京工业职业技术学院学报》2006,5(1):12-14

测量公法线长度是齿轮精度检验常用的方法之一,在齿轮设计、齿轮精度检验及齿轮测绘中应用广泛.测量公法线长度的工具简单,测量技术易掌握且能保证测量精度,基本可以满足普通齿轮的精度测量与测绘计算.  相似文献   

A Simple Model to Determine the Efficient Duration of Exams     

Jules L. Ellis 《Educational and psychological measurement》2021,81(3):549

This study develops a theoretical model for the costs of an exam as a function of its duration. Two kind of costs are distinguished: (1) the costs of measurement errors and (2) the costs of the measurement. Both costs are expressed in time of the student. Based on a classical test theory model, enriched with assumptions on the context, the costs of the exam can be expressed as a function of various parameters, including the duration of the exam. It is shown that these costs can be minimized in time. Applied in a real example with reliability .80, the outcome is that the optimal exam time would be much shorter and would have reliability .675. The consequences of the model are investigated and discussed. One of the consequences is that optimal exam duration depends on the study load of the course, all other things being equal. It is argued that it is worthwhile to investigate empirically how much time students spend on preparing for resits. Six variants of the model are distinguished, which differ in their weights of the errors and in the way grades affect how much time students study for the resit.  相似文献   

字词条件下聋生唇读汉字语音识别的实验研究   总被引：4，自引：1，他引：4  

雷江华  张凤琴  方俊明 《中国特殊教育》2004,(11)

本研究采用 2× 3两因素被试内实验设计 ,探讨了聋生唇读语音识别中词长效应和音素可见性的影响。结果发现 :聋生单字条件的正确识别率高于词语首字 ,且存在显著差异 :唇读汉字语音进行声母、单韵母、复韵母识别效果存在极其显著差异 ,识别正确率从高到低依次为单韵母、复韵母、声母 ;字词条件与音素水平之间交互作用不显著。  相似文献   

Fast combination of scheduling chains under resource and time constraints     

WANG Ji-min PAN Xue-zeng WANG Jie-bing SUN Kang 《浙江大学学报(A卷英文版)》2007,8(1):119-126

  相似文献   

计算共价键长的经验公式     

徐永群 《黄冈师范学院学报》1997,(1)

用逐步回归分析法，发现电负性与键长的相关性较好，并提出了计算共价键键长的经验公式．  相似文献   

中美航线飞越北极最短时间     

张占锋  王庆禄 《唐山师范学院学报》2006,28(2):75-77

利用把不定长转化为定长和建立数学模型的方法,借助空间立体图形、函数、控制测量学、计算机编程及物体间相互运动等知识,解决了从北京到底特律飞行航线最短,应用于实际中。  相似文献   

最优专利长度与宽度设计研究   总被引：3，自引：0，他引：3  

江旭  高山行  周为 《科学学研究》2003,21(2):191-194

专利制度在授予专利权人垄断权利的同时 ,必然会产生专利权人享有垄断期限的长短和垄断程度的大小问题 ,前者即专利长度 ,而后者是专利宽度的问题。专利长度是专利受到法律保护的年限 ,专利宽度的定义多种多样 ,我们把专利宽度定义为政府对专利保护的严厉程度。如何设计最优的专利长度与宽度以使全社会的净福利达到最大化 ,以及设计何种专利保护方向以平衡专利权人、模仿者以及社会公众的利益 ,是本文将要讨论的主题。  相似文献