基于VAR模型的新冠肺炎疫情对航运市场的溢出效应分析     

杨佳琳  葛颖恩 《上海海事大学学报》2021,42(3):59-64

为分析新冠肺炎疫情对航运市场的影响,识别后疫情时代航运市场的潜在风险,用向量自回归(vector autoregression, VAR)和方差分解的方法测算疫情对航运市场的溢出效应。以各国家或地区新冠肺炎累计确诊人数比例代表其疫情严重程度;为消除季节性因素,以航运市场指标与上一年的同比变化率代表航运市场情况。结果显示：油船运输市场、干散货运输市场和集装箱船运输市场均受到新冠肺炎疫情的影响,但不同经济体因其在相对应的贸易市场中的供求关系不同,以及经济体对疫情的控制程度不同,所呈现的溢出效应关系亦不相同。  相似文献   

文化人类学视野中的游戏、体育与民族传统体育   总被引：3，自引：0，他引：3  

王广进 《体育与科学》2010,31(1)

从人类学的研究视角出发,以文献综述和逻辑推理为主要研究方法,把游戏、体育和民族传统体育之间的关系作为研究对象.主要研究结果有:游戏的本质是自由,它标准化之后的形态--体育的本质也是如此;游戏是体育和民族传统体育的根源,而体育和民族传统体育之间没有必然的因果关系;脱离体育的源头和它所依存的文化内涵而解读体育,从而想当然地阐述民族传统体育,是不科学的;必须从人类学的视野来重新思考体育和民族传统体育.  相似文献   

Digital Module 31: Testing Accommodations for Students with Disabilities     

Benjamin J. Lovett 《Educational Measurement》2023,42(1):112-113

Students with disabilities often take tests under different conditions than their peers do. Testing accommodations, which involve changes to test administration that maintain test content, include extending time limits, presenting written text through auditory means, and taking a test in a private room with fewer distractions. For some students with disabilities, accommodations such as these are necessary for fair assessment; without accommodations, invalid interpretations would be made on the basis of these students’ scores. However, when misapplied, accommodations can also diminish fairness, introduce new sources of construct-irrelevant variance, and also lead to invalid interpretation of test scores. This module provides a psychometric framework for thinking about accommodations, and then explicates an accommodations decision-making framework that includes a variety of considerations. Problems with current accommodations practices are discussed, along with potential solutions and future directions. The module is accompanied by exercises allowing participants to apply their understanding.  相似文献   

基于MATLAB的复合因子方差分析与主成分分析算法设计     

薛亚宏  王嘉  程喜林 《安阳工学院学报》2022,21(2):92-95

方差分析与主成分分析是工程计算领域重要的统计分析方法,特别是在医学研究、科学试验、生物遗传测序等方面有广泛应用,本文基于MATALB工具,对双因子方差分析、主成分分析两种主要类型进行理论描述和算法设计,从而实现对抽样样本的二维数据分析。  相似文献