Examining type I error and power for detection of differential item and testlet functioning

In this study, the effectiveness of detection of differential item functioning (DIF) and testlet DIF using SIBTEST and Poly-SIBTEST were examined in tests composed of testlets. An example using data from a reading comprehension test showed that results from SIBTEST and Poly-SIBTEST were not completely consistent in the detection of DIF and testlet DIF. Results from a simulation study indicated that SIBTEST appeared to maintain type I error control for most conditions, except in some instances in which the magnitude of simulated DIF tended to increase. This same pattern was present for the Poly-SIBTEST results, although Poly-SIBTEST demonstrated markedly less control of type I errors. Type I error control with Poly-SIBTEST was lower for those conditions for which the ability was unmatched to test difficulty. The power results for SIBTEST were not adversely affected, when the size and percent of simulated DIF increased. Although Poly-SIBTEST failed to control type I errors in over 85% of the conditions simulated, in those conditions for which type I error control was maintained, Poly-SIBTEST demonstrated higher power than SIBTEST.     

关于微分形式不变性的应用

微分形式不变性对于隐函数（组）求偏导,无需知道各变量之间的关系,只要把所有变量都看成独立变量来处理,就可以给类似这样的求偏导带来许多方便。此外,微分形式不变性在多元函数求极值上也有应用。     

基于压力的旅游者旅游行为分异特征研究

旅游可以改善人们的生活状态,深入探究旅游与压力的关系,让旅游消费活动成为更直接的解压途径,充分体现旅游的民生意义。湛江市是一个具有多元旅游产品的旅游目的地,可以满足旅游者多种旅游消费需求。通过对湛江主要景区旅游者的抽样调查,采用聚类方法得到不同压力源的旅游者类型,发现不同压力类型旅游者的旅游行为在旅游花费、出游方式、获取信息渠道三个方面表现出明显的分异色彩,在出游目的、目的地类型、旅游住宿、交通工具四个方面的分异不明显。     

Do the rich get richer and the poor poorer?: The effects of an intervention programme on reading in the home and school language in a high poverty multilingual context

There is little research on differential reading performance in multilingual contexts in less than ideal learning conditions. This article reports on a reading intervention project in a poor multilingual primary school in South Africa where reading levels in Northern Sotho (home language) and English (language of schooling) were initially very low amongst Grade 7 learners. The nature of the reading intervention is briefly sketched and the outcomes after three years of implementation presented. Results at the intervention school showed some Matthew effects in both languages. Differential reading performance is discussed in relation to the high poverty and multilingual context of the school. Although this is a single case longitudinal study, implications for reading interventions and classroom instruction are considered in the context of disadvantaged multilingual primary schools.     

生态移民政策对农户收入影响机理研究——基于形成型指标的结构方程模型分析

生态移民政策评估是多学科领域的热点问题,而机理研究是其关键环节。本研究通过构建“生态移民政策→生计资本→收入”分析框架,以生计资本为中介变量,选择形成型指标建立结构方程模型分析生态移民政策对收入的影响机理,采用偏最小二乘回归方法估算路径系数,测算生态移民政策对收入的直接效应、间接效应和总效应,验证生态移民政策影响收入作用机理的有效性。陕南和宁夏的生态移民分别是城镇化社区安置和新农村安置的典型,通过实证分析两地生态移民政策作用机理,针对关键生计资本提出优化措施,以增加农户生计资本并长效促进收入提高。研究表明：两种类型的生态移民政策通过人力资本、社会资本、金融资本和物质资本对农户收入均有正向作用,但是影响大小略有区别。陕南地区的生态移民政策通过社会资本改善农户收入的作用最强,人力资本次之,金融资本和物质资本相对较小;宁夏地区的生态移民政策通过金融资本改善农户收入的作用最强,人力资本次之,社会资本和物质资本相对较小,自然资本具有微弱的负向影响。总体而言,生态移民政策的实施能有效促进农户生计资本存量的积累,进而产生稳定可持续的收入流量。     

产学研金合作共生要素对企业创新绩效的影响

基于共生理论,从共生单元、共生模式和共生环境三个维度分析产学研金合作的共生要素,并提出合作共生要素对企业创新绩效影响的研究假设,以生物制药、化工、电子和机械设备等多个不同领域的376家企业为研究对象进行实证分析,利用结构方程模型对研究假设进行验证。研究结果表明,产学研金合作共生要素中,对企业创新绩效影响最大的要素为共生模式,其次为共生环境,影响程度最弱的为共生单元。针对研究结论提出企业创新绩效提升的建议。     

学术期刊媒体融合发展的逻辑、模式与实践

【目的】 探索学术期刊内容生产、知识供给、定点推送和差异服务的深度融合之道。【方法】 通过文献研究法、访谈法以及对国内个别学术期刊媒体融合的实践分析,探索学术期刊媒体融合发展的新模式。【结果】 在媒体融合发展逻辑的指导下,学术期刊应积极顺应媒体融合之大势,主动关注领域重点、热点及前沿学术议题,抢占先发优势,积极谋求权威媒体的间接传播,拓宽信息传播渠道,开展多种数据格式的网络出版,实现信息定点推送和差异服务,以建构“学术期刊+移动互联网+服务”的“121”融合模式,构筑“作者—读者—编者”之间无障碍实时交互机制。【结论】 学术期刊媒体融合的“121”模式能够有效推动学术期刊媒体融合进程,实现学术信息的广泛传播。     

上海市、东京市及太原市部分地区成年人身体成分的比较研究

通过对当今上海市部分地区青年组(20-29岁)、中年组(50-59岁)两组成年人和经济发达的日本东京市部分地区及我国中部的山西太原市部分地区同龄人身体成分进行比较研究,进一步明确这几个城市该年龄段人群身体成分状况、肥胖程度及肥胖部位的异同,并且通过对长岭公式推算的体脂百分比与欧姆龙生物电阻抗测得的体脂百分比进行比较研究,从而检验铃木-长岭和Brozek体脂率预测公式是否适用于中国国民.结果显示:(1)东京市和太原市青年男女身高、体重均大于上海市;中年男子没有差异;中年女子东京市身高低于上海市、体重高于上海市,太原市中年女子身高高于东京市但没有差异,体重略高于东京市,太原市中年女子身高低于上海市而体重略高于上海市;(2)上海市、东京市和太原市成年人身体肥胖部位不一样、肥胖的敏感部位不同,上海市成年人的脂肪敏感部位主要为腹部,东京成年人的敏感部位主要为上臂皮褶厚度和肩胛部皮褶厚度、太原市成年人的敏感部位主要为臀围和上臂皮褶厚度;(3)铃木-长岭和Brozek体脂率推测公式不适用于我国国民.     

从《乡土中国》解读中国社会——读《乡土中国》有感

费孝通在《乡土中国》中介绍了一个带“土性”的中国,提出了“差序格局”的概念,这为分析中国的社会秩序提供了一个理论观点。费孝通提出的社会学本土化、文化自觉的观点对中国社会的理解和认识,对社会学的发展都有着重大意义。     

High-performance hardware architecture of elliptic curve cryptography processor over GF（2^163）

We propose a novel high-performance hardware architecture of processor for elliptic curve scalar multiplication based on the Lopez-Dahab algorithm over GF（2^163） in polynomial basis representation. The processor can do all the operations using an efficient modular arithmetic logic unit, which includes an addition unit, a square and a carefully designed multiplication unit. In the proposed architecture, multiplication, addition, and square can be performed in parallel by the decomposition of computation. The point addition and point doubling iteration operations can be performed in six multiplications by optimization and solution of data dependency. The implementation results based on Xilinx VirtexⅡ XC2V6000 FPGA show that the proposed design can do random elliptic curve scalar multiplication GF（2^163） in 34.11 μs, occupying 2821 registers and 13 376 LUTs.