中国足球超级联赛U23新政何以有效?——基于“足协-俱乐部”的博弈     

花楷  刘晓宇  胡凯  隆丽珊 《武汉体育学院学报》2020,54(8):72-80

中超联赛自2017赛季推出U23新政以来备受争议。在"上有政策下有对策"的非合作博弈下，U23新政如何才能实现政策初衷?该文首次采用不完全信息静态博弈模型分析了U23新政下足协与俱乐部的博弈均衡。研究表明：（1）足协推行新政的最优概率为俱乐部采取积极策略给足协带来的净收益与消极策略带来的净收益之比，实质上取决于俱乐部的遵从度。（2）在缺乏讨价还价权时，俱乐部对新政采取消极应对策略是为了减少净损失。俱乐部积极应对的最优概率为消极应对的净损失占其与积极应对的加成即期收益损失之和的比值，实为两害相权取其轻。为激励俱乐部采取积极策略，应降低俱乐部消极应对策略的净收益或积极应对策略的加成即期收益。（3）提高U23新政有效性的治标之策是减少U23政策对中下游球队的冲击，实行有差别的U23政策；对U23球员上场时间低于均值的俱乐部，实行等额或超额递减分成机制。治本之策是培育一个可预期、可持续、可盈利的足球市场，俱乐部能够内生出建立百年基业的长效机制；继续深化足协的去行政化改革，使之向完全社团法人转型。  相似文献   

Protective behavior in ride-sharing through the lens of protection motivation theory and usage situation theory     

《International Journal of Information Management》2021

The frequent occurrence of security incidents in ride-sharing is a challenge for the survival of IT-enabled ride-sharing platforms. Passengers’ protective behavior is an effective means to alleviate this issue, with benefits to both the passengers and the platforms. This study explores the mechanisms of passengers’ protective behavior in the ride-sharing context by combining protection motivation theory (PMT) and usage situation theory. We test our hypotheses using data (n = 346) collected from a field survey based on a real scenario. The findings reveal that PMT and usage situation theory work well to explain passengers’ protective behavior during ride-sharing. This study explains the motivation behind passengers’ protective behavior in the ride-sharing context, extends the contents of PMT by exploring its antecedents, and extends the contents of usage situation theory by introducing a new dimension. Our findings can help ride-sharing platforms take appropriate strategies to improve passengers’ protective behavior.  相似文献   

面向社交媒体的细粒度ADR本体的半自动构建方法研究     

魏巍  傅维刚 《图书情报工作》2019,63(3):108-114

[目的/意义]提出一个药物不良反应本体的半自动构建方法，构建的细粒度药物不良反应本体为利用社交媒体挖掘潜在的药物不良反应信号提供语义资源库。[方法/过程]首先，采用业务层次和语言层次相分离的设计理念，将用户在社交媒体中评论的药物不良反应表示成"对象要素-属性要素-描述概念"的形式。细粒度体现在社交媒体用户对药物同一不良反应描述概念表达的多样性上。然后，基于深度学习的思想，利用基于word2vec的描述概念候选词抽取算法自动地抽取出更多的描述概念候选词构建本体。[结果/结论]以糖尿病药物的建模实例表明，提出的细粒度药物不良反应本体的半自动构建方案，提高了本体构建的智能化水平，构建的细粒度药物不良反应本体为利用社交媒体挖掘潜在的药物不良反应信号提供语义资源库。  相似文献   

Bio-inspired untethered fully soft robots in liquid actuated by induced energy gradients     

Liang Xiong Lyu  Fen Li  Kang Wu  Pan Deng  Seung Hee Jeong  Zhigang Wu  Han Ding 《国家科学评论(英文版)》2019,6(5):970

Soft robotics with new designs, fabrication technologies and control strategies inspired by nature have been totally changing our view on robotics. To fully exploit their potential in practical applications, untethered designs are preferred in implementation. However, hindered by the limited thermal/mechanical performance of soft materials, it has been always challenging for researchers to implement untethered solutions, which generally involve rigid forms of high energy-density power sources or high energy-density processes. A number of insects in nature, such as rove beetles, can gain a burst of kinetic energy from the induced surface-energy gradient on water to return to their familiar habitats, which is generally known as Marangoni propulsion. Inspired by such a behavior, we report the agile untethered mobility of a fully soft robot in liquid based on induced energy gradients and also develop corresponding fabrication and maneuvering strategies. The robot can reach a speed of 5.5 body lengths per second, which is 7-fold more than the best reported, 0.69 (body length per second), in the previous work on untethered soft robots in liquid by far. Further controlling the robots, we demonstrate a soft-robot swarm that can approach a target simultaneously to assure a hit with high accuracy. Without employing any high energy-density power sources or processes, our robot exhibits many attractive merits, such as quietness, no mechanical wear, no thermal fatigue, invisibility and ease of robot fabrication, which may potentially impact many fields in the future.  相似文献   

Understanding the topic evolution of scientific literatures like an evolving city: Using Google Word2Vec model and spatial autocorrelation analysis     

Kai Hu  Qing Luo  Kunlun Qi  Siluo Yang  Jin Mao  Xiaokang Fu  Jie Zheng  Huayi Wu  Ya Guo  Qibing Zhu 《Information processing & management》2019,56(4):1185-1203

Topic evolution has been described by many approaches from a macro level to a detail level, by extracting topic dynamics from text in literature and other media types. However, why the evolution happens is less studied. In this paper, we focus on whether and how the keyword semantics can invoke or affect the topic evolution. We assume that the semantic relatedness among the keywords can affect topic popularity during literature surveying and citing process, thus invoking evolution. However, the assumption is needed to be confirmed in an approach that fully considers the semantic interactions among topics. Traditional topic evolution analyses in scientometric domains cannot provide such support because of using limited semantic meanings. To address this problem, we apply the Google Word2Vec, a deep learning language model, to enhance the keywords with more complete semantic information. We further develop the semantic space as an urban geographic space. We analyze the topic evolution geographically using the measures of spatial autocorrelation, as if keywords are the changing lands in an evolving city. The keyword citations (keyword citation counts one when the paper containing this keyword obtains a citation) are used as an indicator of keyword popularity. Using the bibliographical datasets of the geographical natural hazard field, experimental results demonstrate that in some local areas, the popularity of keywords is affecting that of the surrounding keywords. However, there are no significant impacts on the evolution of all keywords. The spatial autocorrelation analysis identifies the interaction patterns (including High-High leading, High-Low suppressing) among the keywords in local areas. This approach can be regarded as an analyzing framework borrowed from geospatial modeling. Moreover, the prediction results in local areas are demonstrated to be more accurate if considering the spatial autocorrelations.  相似文献   

人类发展指数水平与足球运动发展的或然关系——基于面板数据的实证研究     

傅鸿浩  刘波  张廷安  龚波  郭振  肖辉 《武汉体育学院学报》2020,54(11):20-26

足球运动在世界范围内的普及化与社会化程度日益增强，各国（地区）若要获得全球化竞争中的优势，应注重探讨社会与足球运动发展的关系。通过对1993-2017年131个国家（地区）的人类发展指数与足球排名积分的面板数据建模，以揭示两者之间的关系。研究结果表明，不同国家（地区）的人类发展指数对足球运动发展的影响应建立个体和时点双固定效应模型，模型最高的R²为0.871 32，F检验值为71.014 65，P<0.001，该模型具备较高的解释能力。结论：固定效应模型在考虑历时性因素与不宜观测因素后，在1993-2017年阶段，人类发展指数对于足球运动的发展作用存在分化现象，尤其对亚洲与人口大国的足球运动发展存在制约作用，对南美洲与中等人口国家存在促进作用，人类发展指数与足球运动发展存在一定的或然关系。人类发展指数反映了社会发展的综合水平，对于存在制约效应的国家而言，应当着重考虑社会其它领域（经济、教育、医疗卫生等）与足球运动的互动、协同与融合发展。  相似文献   

竞技攀岩溯源与演变研究     

李元  朱倍锋 《武汉体育学院学报》2020,54(11):87-93

竞技攀岩作为新晋奥运项目，探究其起源和演变过程可为我国竞技攀岩的发展提供借鉴、指导及理论缘由。采用文献资料研究和逻辑分析方法，探讨了竞技攀岩的概念，分析了竞技攀岩诞生的装备和技术基础、社会文化背景，以及三个发展阶段的主要特征。研究表明，竞技攀岩是攀岩运动中符合现代竞技体育特征的部分，是攀岩运动"竞技体育化"的结果；器械装备升级提供的技术基础和战后复兴的历史背景，共同促成了竞技攀岩在苏联的诞生；竞技攀岩的演变经历了苏联时期的普及化与国际化尝试、UIAA主导的竞技攀岩国际管理体系与赛事体系建设、IFSC引领的奥运发展新时期三个阶段；竞技攀岩的后奥运时代将迎来前所未有的发展契机。  相似文献   

Optimal control methodology for the Counter-Terrorism strategies: The relaxation based approach     

《Journal of The Franklin Institute》2022,359(13):6690-6708

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自动跟踪补偿消弧线圈在配电网中的选用     

卢施远 《黄冈职业技术学院学报》2011,13(3):99-102

目前,我国城市配电网中电力电缆的应用愈来愈广泛,系统电容电流越来越大,在发生单相接地时电弧不能熄灭,会造成电弧间歇性的熄灭与重燃,形成弧光接地电压或激发磁谐振危及电气设备绝缘,严重时有可能发展为相间短路,引起事故。为限制单相接地故障电流,6-35KV系统采用中性点通过消弧线圈接地来补偿单相接地时的电容电流使电弧熄灭,限制弧光接地过电压和消除铁磁谐振过电压,现已取得较多的运行经验和较好运行效果。  相似文献   

教学中的语境关怀研究——以中国共产党思想史教学为例     

谢辉  韦磊  张秀荣 《大学教育科学》2011,(2):42-45

中国共产党思想史教学中的语境关怀既是适应学术发展趋势的需要,更是语境在中国共产党思想史中的重要作用决定的;中国共产党思想史中语境主要包括话语的历史文化环境、篇章语境和篇章内语境;将语境纳入到中国共产党思想史教学中应该坚持:层次性与整体性相结合原则;静态性与动态性相结合原则;尊重客体语境客观性与规避主体语境原则;在中国共产党思想史中主观语境和客观语境的区别与综合原则等。  相似文献