An analysis of the reach and effectiveness of distance learning in India during school closures due to COVID-19     

《International Journal of Educational Development》2021

In India, more than 276 million children and youth were out of school for extended periods since March 2020 due to school closures in response to COVID-19. A key challenge has been how to measure the impact of responses to continuity of learning both to ensure more effective responses in the event of further disruptions, but also to help the education community conceptualize more creative and effective approaches to learning, through blended and flexible approaches. This study reflects on the findings from a UNICEF survey targeting parents and adolescents across 6 states in India, and identifies lessons learned for addressing learning inequities during future school closures. We focus on measuring three key variables – access to technology, their utilization, and perceived learning for different profiles of children. As students began learning from home, technology access rates in households were initially used to determine the estimated maximum reach of different distance learning modalities during school closures. Beyond access, we find significant variations in adolescents’ use of technology for learning purposes and their perceptions of learning, linked to the type of remote learning modality, gender, location and type of school. We discuss the implications for government strategies and policies to ensure better utilization of technologies which are available in households and to address equity gaps in learning opportunities.  相似文献   

Online portfolio management via deep reinforcement learning with high-frequency data     

《Information processing & management》2023,60(3):103247

Recently, models that based on Transformer (Vaswani et al., 2017) have yielded superior results in many sequence modeling tasks. The ability of Transformer to capture long-range dependencies and interactions makes it possible to apply it in the field of portfolio management (PM). However, the built-in quadratic complexity of the Transformer prevents its direct application to the PM task. To solve this problem, in this paper, we propose a deep reinforcement learning-based PM framework called LSRE-CAAN, with two important components: a long sequence representations extractor and a cross-asset attention network. Direct Policy Gradient is used to solve the sequential decision problem in the PM process. We conduct numerical experiments in three aspects using four different cryptocurrency datasets, and the empirical results show that our framework is more effective than both traditional and state-of-the-art (SOTA) online portfolio strategies, achieving a 6x return on the best dataset. In terms of risk metrics, our framework has an average volatility risk of 0.46 and an average maximum drawdown risk of 0.27 across the four datasets, both of which are lower than the vast majority of SOTA strategies. In addition, while the vast majority of SOTA strategies maintain a poor turnover rate of approximately greater than 50% on average, our framework enjoys a relatively low turnover rate on all datasets, efficiency analysis illustrates that our framework no longer has the quadratic dependency limitation.  相似文献   

上海“体教结合”举措下竞技体育后备人才“学生-运动员”双重角色的认同、冲突与转化          下载免费PDF全文

侯爽 《体育科研》2019,(3):30-37

“体教结合”是解决当前我国竞技体育发展问题的重要途径和举措。传统的体育后备人才培养模式只重视专项体育技能的发展而忽视了文化教育的重要性，不利于个体的全面发展。“体教结合”更重视人的全面发展，体育与教育的融合，使得竞技体育人才逐渐从运动员这一单一角色向“学生-运动员”双重角色转变。研究以角色认同为切入口，探讨上海“体教结合”举措下，角色的转变对体育竞技后备人才的影响。选取上海体育学院中国乒乓球学院少年班学员作为“学生-运动员”样本，选取国家乒乓球青年队及部分省市队队员作为职业运动员样本，使用结构化心理测量工具，对比两类受访者在运动与学业上的角色认同、心理倦怠与动机变量的差异。得出：在上海“体教结合”举措下，竞技体育后备人才认同“学生-运动员”双重角色，他们在学业任务中的卷入程度更高；双重角色使运动员在运动任务与学业任务上的主观价值感存在差异，表现出双重角色之间的冲突，但对个体的整体人生规划并不冲突；双重角色之间的转化，对于“学生-运动员”的心理健康存在促进效应。  相似文献   

Static and dynamic accuracy of a magnetic-inertial measurement unit used to provide racket swing kinematics     

Benjamin Kane Williams  Ross H. Sanders  Joong Hyun Ryu  Pitre C. Bourdon  Philip Graham-Smith  Peter J. Sinclair 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(2):202-214

Magnetic-inertial measurement units (MIMUs) are becoming more prevalent in sports biomechanics and may be a viable tool to evaluate kinematic parameters. This study examined the accuracy of a MIMU to estimate orientation angles under static conditions and dynamically from a squash racket during a forehand drive shot. A MIMU was mounted onto a goniometer and moved through 0–90°, with static data collected at 10° increments during 10 repetitions of all three axes. Typical error analyses showed the MIMU to be very reliable (TE ≤ 0.03°). MIMU accuracy was determined via intraclass correlation coefficients (ICC) (r > 0.999, p < 0.001). An ordinary least products regression showed no proportional bias and minimal fixed bias for all axes. Dynamic accuracy was assessed by comparing MIMU and optical motion capture data of squash racket swing kinematics. A MIMU was fixed onto a racket and 10 participants each hit 10 forehand shots. Mean orientation angle error at ball impact was <0.50° and ICC showed very high correlations (r ≥ 0.988, p < 0.001) for all orientations. Swing phase root mean squared errors were ≤2.20°. These results indicate that a MIMU could be used to accurately and reliably estimate selected racket swing kinematics.  相似文献   

Nostalgia,homesickness and emotional formation on the eighteenth-century Grand Tour     

Sarah Goldsmith 《Cultural and Social History》2018,15(3):333-360

Nostalgia and homesickness were well-known eighteenth-century ailments. Undertaking protracted travels, Grand Tourists were potential sufferers, yet these emotional afflictions are absent from the Tour's lengthy lists of hazards. Querying this and applying history of emotions approaches to the histories of the Tour, masculinity and the family, this article examines how Tourists and tutors navigated nostalgia and homesickness as emotions that sat uneasily with the Tour's wider aims of masculine formation. Such investigations offer a means of unpicking the complex, contradictory demands placed on young gentlemen during their emotional formation. Through this, it contributes to wider reconsiderations of eighteenth-century masculinity.  相似文献   

The Eton Montem custom c. 1750–1844: privilege,pageantry and sanctioned misrule     

Catherine Dille 《Cultural and Social History》2018,15(3):361-377

Montem, a triennial customary march by Eton scholars, consolidated into a public expression of patrician social identity under the patronage of the monarchy in the late eighteenth century. This analysis of Montem’s history traces its development from a boy-led pageant of misrule to a public performance of elite patriotism. The custom, which attracted national attention, sheds new light on boy governance and self-fashioning in the period’s elite schools. This article argues that a study of Montem disrupts the standard historiographical narrative of anarchy and violence in the great schools and suggests that boy culture was more complex than previously acknowledged.  相似文献   

Bayesian reasoning in avalanche terrain: a theoretical investigation     

Philip A. Ebert 《Journal of Adventure Education & Outdoor Learning》2019,19(1):84-95

In this article, I explore a Bayesian approach to avalanche decision-making. I motivate this perspective by highlighting a version of the base-rate fallacy and show that a similar pattern applies to decision-making in avalanche-terrain. I then draw out three theoretical lessons from adopting a Bayesian approach and discuss these lessons critically. Lastly, I highlight a number of challenges for avalanche educators when incorporating the Bayesian perspective in their curriculum.  相似文献   

From objects to subjects: Repositioning teachers as policy actors doing policy work     

《Teaching and Teacher Education》2018

Within policy discourses, teachers are positioned as objects of reform who enact policies under rational systems of observation and accountability and are, therefore, situated as de-professionalized actors lacking expert knowledge. This research project asks relatively straight-forward questions: If practicing teachers were given a voice in political debates over urban education policy and reform, what would they say? What macro-level policy problems would they identify as being important? Findings indicate the primary policy problems include Systemic Inequity and Bad Policy. The primary policy solutions include, Schools as a Community Resource; Shared Decision-Making; Contextual Goals; and Time, Space and Resources.  相似文献   

The Impact of Receivers’ Nationality and Cultural Orientation on the Effects of Fear Appeals in Health Communication     

Carel Jansen  Geke van der Kroef 《Journal of Intercultural Communication Research》2019,48(1):72-90

Participants from the Netherlands (n = 52), China (n = 50), and South Africa (n = 166) either read a self-targeted or a family-targeted fear appeal message about chlamydia. Seven aspects of individual cultural orientation were measured, and six effects of the different messages. Interactions between nationality and target of threat were found on perceived severity, perceived susceptibility, and danger control. Only for perceived susceptibility, a difference in cultural orientation partly explained this interaction. The outcomes add to the doubts about claims in earlier literature about the relevance of receivers’ nationality and cultural orientation for developing a fear appeal message.  相似文献   

体育文化交流对中美关系改善的作用及启示——基于中美建交40年的历史考察     

肖焕禹  倪京帅 《武汉体育学院学报》2019,53(10):12-18

运用文献资料等研究方法，基于"契机-轨迹"理论，对中美建交40年来体育文化交流情况进行了回顾和梳理，分析了外交政策导向下中美体育文化交流"契机"的形成和"轨迹"的发展，解读中美建交的历史背景和体育文化交流的特征与价值。认为：在"和平与发展""构建开放合作和谐社会""新时代构建新型国际关系"外交政策的影响下，中美体育文化交流具有体育文化财富的共享性、体育竞技的对等性、体育文化交流的公共性特征；中美体育文化交流促进中美建交，促进中美和平发展；改变世界格局，获得话语权；树立国家形象，展示大国责任；深化体育改革，促进社会发展。  相似文献