基于γ-散度的稳健有序误标记logistic回归     

郭美君  任明旸  李仕明  张三国 《中国科学院大学学报》2022,39(3):289-301

有序多分类方法已经得到了广泛研究。传统的有序多分类方法假设样本的类别标签是不存在误标记的。但是由于实际数据复杂以及人工经验有限,获得标记完全正确的样本是不现实的,因此,传统的方法就存在局限性。提出一种基于γ-散度的有序误标记logistic回归方法,在处理存在误标记的有序多分类问题时具有很强的稳健性,也就是说,当某一样本被错误标记时它对参数估计的权重小于其被正确标记时的权重。该方法通过最小化γ-散度构建模型,利用梯度下降算法求解模型,不仅具有很强的稳健性而且在模型中可以忽略误标记概率。模拟研究和真实数据分析都说明该有序误标记logistic回归方法在处理存在误标记的有序分类问题时效果很好。  相似文献   

Physical activity and nutrition guidelines to help with the fight against COVID-19     

Kayvan Khoramipour  Aref Basereh  Amirhoseein Ahmadi Hekmatikar  Lindy Castell  Ruheea Taskin Ruhee 《Journal of sports sciences》2021,39(1):101-107

ABSTRACT

As the world is witnessing the epidemic of coronavirus disease 2019, emerging genetics and clinical pieces of evidence suggest a similar immunopathology to those of severe acute respiratory syndrome and Middle East respiratory syndrome. Staying at home to prevent the spread of the virus and consequently being largely inactive is associated with unintended consequences. These can actually enhance the infection risk and exacerbate poor health conditions including impaired immune function. Physical activity is a feasible way of improving health, particularly physical and mental health in a time of social isolation. However, people with certain health conditions in these circumstances may need a special physical activity programme in addition to any exercise they may already be performing via online programmes. This review aims to provide practical guidelines during the COVID-19 quarantine period. We suggest performing aerobic, resistance training, respiratory muscle training and yoga in the healthy, and in those with upper respiratory tract illness, patients with lower respiratory tract illness should be restricted to respiratory muscle training and yoga. In addition, vitamins D and C, omega-3 fatty acids, and regular consumption of fruit and vegetables might be considered as nutritional aids to support the immune system in those affected by COVID-19.  相似文献   

Test Development with Performance Standards and Achievement Growth in Mind     

Steve Ferrara  Dubravka Svetina  Sylvia Skucha  Anne H. Davidson 《Educational Measurement》2011,30(4):3-15

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Managing What We Can Measure: Quantifying the Susceptibility of Automated Scoring Systems to Gaming Behavior     

Derrick Higgins  Michael Heilman 《Educational Measurement》2014,33(3):36-46

As methods for automated scoring of constructed‐response items become more widely adopted in state assessments, and are used in more consequential operational configurations, it is critical that their susceptibility to gaming behavior be investigated and managed. This article provides a review of research relevant to how construct‐irrelevant response behavior may affect automated constructed‐response scoring, and aims to address a gap in that literature: the need to assess the degree of risk before operational launch. A general framework is proposed for evaluating susceptibility to gaming, and an initial empirical demonstration is presented using the open‐source short‐answer scoring engines from the Automated Student Assessment Prize (ASAP) Challenge.  相似文献   

Children's responses to the interactivity of storybook apps in family shared reading events involving the iPad          下载免费PDF全文

《Literacy》2017,51(1):44-52

This paper reports on some data on the effects of screen‐based interactivity on children's engagement with storybook apps during family shared book reading that were gathered in a 2‐year, small‐scale ethnographic case study in Spain. Data analysis focuses on the complex interplay between the storybook app's interactive features and the children's responses to them. Our findings show that interactive elements increase the child's autonomy, as they tend to promote the importance of the reader, positioning him or her as a collaborator, storyteller, an author or an internal character in the fiction; something that can materialise in exciting narrative strategies that can trigger powerful responses to digital literary texts in emergent readers, including playing, creating new fictions or engaging emotionally with the story. Finally, we argue that the Reader Response models that have been used over recent decades to understand children's reading experiences with storybooks need to be revised to better understand their current experiences with interactive texts.  相似文献   

从新课标看自主学习     

任清敏 《安顺师范高等专科学校学报》2005,7(1):7-8

学习必须主动、独立、创新,培养实际能力.自主学习是指具有自觉的意识和反应的学习方式.自主阅读是自主学习的关键.总结能力是自主学习非常重要的一个方面.自主学习是指教学条件下的学生的高品质的学习.  相似文献   

How to respond to journalists’ questions? A new perspective on Chinese premiers’ aggressiveness at press conferences (1993–2015)     

Feng Wu  Hong Zhao 《亚洲交流杂志》2016,26(5):446-465

This study extends the framework describing journalists’ aggressiveness at politicians’ press conference and develops five dimensions to measure politicians’ aggressiveness in response to journalists’ questions (initiative, directness, assertiveness, adversarialness, and accountability). Using the records from Chinese premiers’ press conferences (1993–2015), this research investigates five factors which might affect premiers’ aggressiveness: the administrative life cycle, economic conditions, journalists’ country of origin, the topic of questions, and number of questions. The results show that premiers exhibit less assertiveness during honeymoon periods and more assertiveness in other years. Premiers are more adversarial amid good economic growth but less adversarial during poor economic growth. They are more assertive and adversarial in response to questions related to politics and the military and less so in response to questions related to other areas. Premiers display more initiative and accountability toward journalists who ask more questions and less toward those who ask fewer questions. Premiers are more assertive and adversarial toward journalists from developed countries but less so toward those from developing countries. Over the past 23 years, premiers’ initiative, directness, and adversarialness have decreased while their accountability has gradually increased. The theoretical contributions of this research are discussed.  相似文献   

论色彩的心理效应   总被引：1，自引：0，他引：1  

李征 《石家庄职业技术学院学报》2004,16(3):45-48

色彩的心理效应主要表现在色彩表情、色彩联想、色彩象征等方面，不同色彩会导致不同的心理效应。  相似文献   

应用软件汉字封面的制作     

吕宏辉  李建萍 《洛阳工业高等专科学校学报》1995,(4)

一个好的应用软件封面往往会给人以好的印象,本文首先介绍了SPT图像文件格式,然后给出了一个制作汉字封面的简单方法。  相似文献   

基于双传递函数模型的线性系统仿真分析     

龚昌来 《嘉应学院学报》2004,22(6):59-61

采用单个传递函数建立的单输入-单输出线性系统模型,仅能用于分析系统的零状态响应 文中采用双传递函数建立系统模型,可全面地分析系统的零状态响应、零输入响应及完全响应  相似文献