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   

困境与应对:聚焦新型冠状病毒肺炎疫情对体育事业的影响     

钟秉枢  黄志剑  王凯  车冰清  宋昱 《南京体育学院学报(社会科学版)》2020,34(2):9-33

2021年实施版《世界反兴奋剂条例》回应了俄罗斯集体兴奋剂事件，加大了对兴奋剂违规行为的打击力度，增强了对运动员权利的保护程度，适应了反兴奋剂技术手段的科学发展。2021年实施版《世界反兴奋剂条例》在新增“阻挠、报复兴奋剂举报”这一类违规行为、增设“受保护的人员”与“业余运动员”新型主体类型、为社会毒品设置单独条款等方面的修订显著成功，但也存在着相关条款之间协调不够、反兴奋剂机构与运动员之间程序权利不平衡等不足。研究分析了2021年实施版《世界反兴奋剂条例》修订条款的主要内容，并考察了修订的主要原因  相似文献   

心脏Nmnat过表达联合耐力运动对果蝇高脂膳食诱发脂毒性心肌症的影响     

文登台  郑澜  陆凯  刘宪楚  后文其 《首都体育学院学报》2020,(1):87-96

利用UAS/hand-gal4系统构建果蝇心脏Nmnat基因特异性过表达,研究心脏Nmnat基因过表达联合耐力运动对高脂膳食诱发脂毒性心肌症的影响,并分析其分子机制。方法:雄性w^1118和NmnatUAS系果蝇分别与雌性hand-Gal4杂交,收集F1代心脏Nmnat正常表达(hand>w^1118)和过表达(hand>Nmnat)处女蝇,饲养至15 d后开始进行耐力运动(E)和高脂膳食(HFD),并分为hand>w^1118、hand>w^1118+E、hand>w^1118+HFD、hand>w^1118+HFD+E、hand>Nmnat、hand>Nmnat+E、hand>Nmnat+HFD、hand>Nmnat+HFD+E共8组,每组410只。ELISA检测心脏TAG、NAD+、SIR2蛋白去乙酰化、SOD活力和MDA水平,qRT-PCR检测心脏相关基因mRNA表达,M-mode检测心脏功能情况。结果:hand>w^1118+HFD+E果蝇心脏的Nmnat、dFoxo、bmm表达、NAD+水平、SIR2去乙酰化、SOD活力、缩短分数高于hand>w^1118+HFD(P<0.05或P<0.01),且d FAS和Col4al表达、TAG和MDA水平、心率和纤维性振颤低于hand>w^1118+HFD(P<0.05或P<0.01);hand>Nmnat果蝇心脏各指标与hand>Nmnat+HFD相比较未见显著差异(P>0.05);hand>Nmnat+HFD+E果蝇心脏的Nmnat、dFoxo、bmm表达、心脏NAD+水平、SIR2去乙酰化、SOD活力、心脏缩短分数高于hand>Nmnat+HFD(P<0.05或P<0.01),且dFAS和Col4al表达\TAG和MDA水平、心率和纤维性振颤低于hand>Nmnat+HFD(P<0.05或P<0.01)。结论:心脏Nmnat过表达和耐力运动均能抵抗果蝇高脂膳食诱发的心脏脂质过度堆积、氧化损伤、减弱心脏收缩能力和增加纤维性振颤,其分子机制与心脏Nmnat/NAD+/SIR2/dFoxo通路活性增强有关。心脏Nmnat基因过表达联合耐力运动能更好地降低脂毒性心肌症的发生概率,其机制与二者联合对心脏Nmnat/NAD+/SIR2/dFoxo通路活性上调的叠加作用有关。  相似文献   

基于深度学习的SSD模型尾矿库自动提取     

闫凯  沈汀  陈正超  闫弘轩 《中国科学院大学学报》2020,37(3):360-367

针对华北地区尾矿库自动提取问题，将基于深度学习的SSD目标检测模型应用于遥感图像尾矿库提取。首先标记华北地区2 000个样本，随机挑选1 500个作为训练样本，剩余样本作为测试样本，验证模型的检测精度。分析卷积层对应感受野与图像中尾矿库尺寸关系，发现原始SSD模型漏检误检大型尾矿库。改进SSD模型结构，提出增加额外卷积层的策略，提高对大型尾矿库目标的检测精度。实验表明，在置信度阈值为0.3时，改进的SSD模型相比原始模型，检测精确率提高10.0%，召回率提高14.4%，提高了大型尾矿库检测精度。验证了基于深度学习的SSD目标检测模型自动提取尾矿库的可行性以及改进算法的有效性。  相似文献   

Leg amputation side determines performance in curve sprinting: a case study on a Paralympic medalist     

Johannes Funken  Kai Heinrich  Steffen Willwacher  Ralf Müller  Jonas Böcker  Hiroaki Hobara 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(1):75-87

The lower limb kinetics of curve sprinting in amputees are not well described in the literature, particularly with respect to the effect of the side of amputation. This is an issue due to the importance of the knowledge for prosthetic design and classification of athletes. Thus, the aim of this study was to investigate the influence of side of amputation on curve sprinting performance in athletes with a unilateral leg amputation. A three-dimensional motion analysis system (Vicon), four force plates (Kistler) and a modified mathematical human model (ALASKA) were used to compare clockwise and counter clockwise curve sprinting lower limb kinematics and kinetics of a Paralympic medalist with a left-sided knee exarticular amputation. Results reveal that vertical ground reaction force application and total vertical impulse were lower when the affected limb was at the inside of the curve. The unaffected limb showed joint mechanics different to those established for non-amputee athletes and might contribute better to propulsion when being the inside limb. Curve sprinting biomechanics and the ability to attain high radial velocities are directly dependent on the side of amputation relative to the curve direction in a unilateral amputee athlete of highest performance level.  相似文献   

江苏省体育健康特色小镇建设现状调查分析          下载免费PDF全文

舒丽  陶玉流  张凯  王小秋 《体育科研》2019,(2):41-48

采用文献资料、实地调研与专家访谈等研究方法，对江苏省体育健康特色小镇的建设愿景与实然状态进行现状调查，并结合全国和江苏省有关体育小镇建设的宏观政策，深度挖掘体育健康特色小镇建设中存在的瓶颈与纠纷，并提出相应的策略。调研得知：江苏省体育健康特色小镇在建设过程中存在建设主体职责不明确，规划建设方向不合理，规划方案编制无灵魂，资源整合工作被忽视和专业人才匮乏等问题。在此基础上，提出找准特色核心项目，科学的规划策划，建立有效的激励与协调机制，倡导辩证的产业思维，实施专业人策略是推进江苏省体育健康特色小镇的重要举措。  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   

Executive functioning and word reading in Hong Kong Chinese children: A 1-year longitudinal perspective     

Wing Kai Fung  Kevin Kien Hoa Chung  Chun Bun Lam 《Journal of Research in Reading》2020,43(3):382-393

This study examined the bidirectionality between kindergarten children's executive functioning (EF) and word reading across two time points. Participants were 523 Hong Kong Chinese-speaking children (mean age at Time 2 = 64.59 months; 52.9% male) and their parents. At Time 1, children were administered the measures of EF skills: inhibitory control, attention shifting, working memory and Chinese word reading. They were reassessed with these measures at Time 2 one year later. Results from the cross-lagged panel model revealed that, controlling for child age, gender and parental education levels, children's word reading at Time 1 was significantly predictive of their working memory at Time 2, but that the three EF skills at Time 1 were not predictive of word reading at Time 2. These findings underscored the role of early word reading in promoting children's working memory.  相似文献   

一种在轨海上多运动舰船目标检测和跟踪方法     

矫腾章  胡玉新  吕鹏  张凯  台宪青 《中国科学院大学学报》2020,37(3):368-378

传统遥感卫星图像处理采用在地面进行目标检测和跟踪处理的模式，卫星将拍摄到的图像数据下传至地面数据处理中心，由地面数据处理系统对接收到的遥感图像数据进行目标检测和跟踪。然而，随着遥感图像分辨率的不断提高，需要下传的数据量增大，导致星地数据传输的时间大大增加，最终造成目标检测和跟踪的时效性降低。针对上述问题，提出一种基于多特征量判别的Canny边缘检测和联合概率数据关联的在轨海上多运动舰船目标检测和跟踪方法。将该方法利用中国科学院微小卫星创新研究院的高分微纳卫星实测数据在模拟星载的嵌入式开发平台上进行验证，结果表明该方法能够在轨对海上多运动舰船目标进行快速、准确的检测和跟踪。  相似文献   

教育中的人工智能:应用、风险与治理研究     

王岚  王凯 《黑龙江高教研究》2020,(6):45-49

  相似文献