众创空间投入与区域科技创新发展关系实证研究     

宋宏  张璐 《科技管理研究》2018,(12)

以众创空间投入及其所在区域科技创新发展状况为对象,以科技进步贡献率为衡量科技创新能力指标,基于线性回归方法和向量自回归模型分析西安市众创空间投入的创新效果及其与西安市科技进步贡献率之间的关系。研究结果表明:加大众创空间投入可以更好地提升众创空间孵化效率,产生良好的创新效果,且该创新效果与科技创新发展之间存在长期正相关关系;科技进步对众创空间创新效果指标的预测方差贡献较大,众创空间对科技发展的预测方差贡献较小。建议采用合理的融资模式与政策组合鼓励建设众创空间,并使用科学合理的运营模式提升众创空间盈利能力,以期获得众创空间良好的创新效益及社会效益。  相似文献   

Biomechanical differences of arm swing countermovement jumps on sand and rigid surface performed by elite beach volleyball players     

George Giatsis  Vassilios Panoutsakopoulos  Iraklis A. Kollias 《Journal of sports sciences》2018,36(9):997-1008

The purpose of this study was to investigate the possible arm swing effect on the biomechanical parameters of vertical counter movement jump due to differences of the compliance of the take-off surface. Fifteen elite male beach-volleyball players (26.2 ± 5.9 years; 1.87 ± 0.05 m; 83.4 ± 6.0 kg; mean ± standard deviation, respectively) performed counter movement jumps on sand and on a rigid surface with and without an arm swing. Results showed significant (p < .05) surface effects on the jump height, the ankle joint angle at the lowest height of the body center of mass and the ankle angular velocity. Also, significant arm swing effects were found on jump height, maximum power output, temporal parameters, range of motion and angular velocity of the hip. These findings could be attributed to the instability of the sand, which resulted in reduced peak power output due to the differences of body configuration at the lowest body position and lower limb joints’ range of motion. The combined effect of the backward arm swing and the recoil of the sand that resulted in decreased resistance at ankle plantar flexion should be controlled at the preparation of selected jumping tasks in beach-volleyball.  相似文献   

Visual function,performance, and processing of basketball players vs. sedentary individuals     

Jesús Vera  Raimundo Jimnez  David Crdenas  Beatriz Redondo  Jos Antonio García 《运动与健康科学(英文)》2020,9(6):587-594

BackgroundAthletes tend to have better visuo-motor performance than do sedentary individuals. However, several basic visual-function and perceptual parameters remain unexplored to date. In this study, we investigated whether differences exist in visual function, performance, and processing between basketball players and individuals without a sport-involvement background.MethodsA total of 33 healthy men with no visual impairment or pathology were divided into 2 groups, depending on the involvement in sport (semi-professional basketball players and sedentary individuals). We tested their baseline heart-rate variability in the resting position apart from subjective questionnaires to determine their physical fitness level, and we checked their visual function, performance, and processing through an extended battery of optometric tests.ResultsThe 2 groups differed in resting heart-rate variability parameters (p < 0.001), confirming their dissimilarities in regular time practising sports per week. The basketball players showed a closer breakpoint and recovery nearpoint of convergence, a higher fusional-vergence rate, better discriminability halos, and better eye–hand coordination (all p values < 0.05).ConclusionThese results show evidence that athletes, basketball players in this case, exhibit better performance in several visual abilities in comparison to a group of individuals without sporting backgrounds, suggesting an improvement due to the systematic involvement of those skills during basketball practice.  相似文献   

Health-related fitness knowledge growth in middle school years: Individual- and school-level correlates     

Xihe Zhu  Justin A. Haegele  Haichun Sun 《运动与健康科学(英文)》2020,9(6):664-669

BackgroundHealth-related fitness knowledge (HRFK) has been an essential concept for many health and physical education programs. There has been limited understanding and longitudinal investigation on HRFK growth. This longitudinal study examined HRFK growth and its individual- and school-level correlates in middle school years under 1 curriculum condition: Five for Life.MethodsParticipants were 12,044 students from 47 middle schools. Data were collected at both individual/participant and school/institution levels. Individual-level variables included gender, grade, and HRFK test scores. School-level variables included percentage of students receiving free and reduced meals (FARM), student-to-faculty ratio for physical education, and school academic performance (SAP). We used hierarchical linear modeling to examine HRFK 3-year growth in relation to individual- and school-level correlates.ResultsThe average HRFK score at 6th grade for females was 42.81% ± 1.32%. The predicted HRFK growth was 17.06% ± 1.02% per year, holding other factors constant. A 1-standard deviation increase in FARM correlated with a 14.68%-point decrease in predicted test score (p = 0.02). A 1-standard deviation increase in SAP was associated with an 11.90%-point increase in HRFK score. Males had a significantly lower growth rate than females during the middle school years (0.78%/year, p = 0.02).ConclusionThe result showed that both individual- and school-level variables such as gender, FARM, and SAP influenced HRFK growth. Educators should heed gender differences in growth curves and recognize the correlates of school-level variables.  相似文献   

我国高尔夫球奥运选手与世界优秀选手一号木数据对比分析     

赵紫龙 《河北体育学院学报》2020,34(6):85-90

采用文献资料法、实地考察法、数理统计法和对比分析法，对我国奥运选手和世界优秀选手的一号木数据进行分析。发现，在实地考察的球洞中，世界优秀选手全四轮均使用一号木开球，而我国男子选手则是一号木、三号木交替开球，可能是由于对自身一号木开球技术不够自信；我国男子选手的一号木平均开球距离、上球道率较世界优秀选手均差距较大；我国女子选手的一号木平均开球距离与世界优秀选手较为接近，但上球道率有待提高。建议，男子选手加强开球距离和上球道率的训练，女子选手加强上球道率的训练；冯珊珊进一步提升开球距离；在比赛前要对场地进行多次熟悉，找到合适的开球策略。  相似文献   

我国SCI收录期刊影响因子相关自被引率的国际比较     

盛丽娜 《中国科技期刊研究》2018,29(1):69-74

【目的】 分析我国SCI收录期刊影响因子相关自被引率(SCR-IF)的状况，进一步解读自引在影响因子中的作用，以利于我国办刊人掌握期刊的发展方向。【方法】 以2015年版SCI收录期刊为研究对象，计算中国和G7国家(美国、英国、德国、法国、日本、意大利、加拿大)、有代表性的新兴国家(韩国、印度、俄罗斯)期刊自被引率(SCR)，同时计算各刊的SCR-IF、非影响因子相关自被引率(SCR-NIF)及二者比值K，对各国期刊的SCR-IF、SCR-NIF、SCR、K值情况进行对比分析。【结果】 各国期刊SCR-IF的均值均大于SCR-NIF和SCR，K的中位值为1.502~1.889；我国SCI收录期刊的SCR-IF、SCR-NIF均小于韩国和俄罗斯，但高于其他8个国家；我国SCI收录期刊中，SCR-IF为0的期刊占比为3.28%，小于各国均值6.21%；我国K>2.0的期刊占比为34.97%，小于各国均值37.19%。【结论】 SCR-IF较SCR更能准确反映期刊自引对影响因子的实际作用。我国SCI收录期刊SCR-IF相对较高，但仍有部分期刊的自引对影响因子没有任何作用，且我国SCI收录期刊的自引较少有人为操控。  相似文献   

马克思再生产模型中的最高、最低积累率     

陶为群 《巢湖学院学报》2011,(4):25-31

马克思的两部类再生产模型中的各部类和全社会最高与最低积累率问题,是尚未获得完满解决的难点问题。本文运用单调函数的性质和求函数最大、最小值方法,通过解析,给出了静态意义下的各部类和全社会最高及最低积累率与两个部类结构参数的函数关系式。并且引用和借鉴《资本论》中的举例,对给出的函数关系式做了算例验证。  相似文献   

高等院校评价教师系统框架之数据来源分析     

郝春林  高俊玉 《教育教学论坛》2020,(13):26-27

高校评教是高校教育教学管理中的重要一环。文章针对目前已有的评教系统数据源单一、数据使用不充分、教师反馈不及时、师生互动性欠佳、学生评教积极性不高等现状,提出了一个高校评教系统新框架,以评教结果的使用范围为目的,反推出评教数据来源应具备多次性和多样性。每学期多次评教,实现教师与学生的互动,促进学生评教积极性,促进教师及时改进教学方法。评教人员除了学生之外,还应包括督导专家和往届生。  相似文献   

国有商业银行如何应对利率市场化改革的风险   总被引：1，自引：0，他引：1  

冯友钊  贺建清 《衡水学院学报》2004,6(3):44-46

利率市场化改革给国有商业银行的经营带来更大的风险,如:竞争风险、信用风险、利率风险、流动性风险等。如何趋利避害,应对风险,笔者认为从4个方面入手:产权制度改革;经营观念的转变;业务上由传统业务向中间业务、表外业务转变,由分业经营向混业经营转变;风险的全面管理。  相似文献   

An Improvement of MPEG-4 Rate Control Algorithm     

鲁照华李华  刘继兴 《天津大学学报(英文版)》2005,11(1):40-43

Frame skipping in low bit video coding could significantly reduce the visual quality of reconstructed video. At the same time, if the complexity of the video sequence remains high for a long period, then driving up the long term average bit rate, the only resort of MPEG-4 Q2 rate control algorithm results in using a high quantization scale, which shows a poor visual quality of the reconstructed video. This paper analyzes the main causes of frame skipping in current MPEG-4 frame rate control scheme, and presents a new rate control algorithm based on the quadratic R-D model over a CBR channel. Key features of the present work are. 1) the bits allocated to each P-frame or B-frame are in proportion to its distance from the end of this GOP, i.e. more bits are allocated to the frames that are nearer to their reference Ⅰ -frame: 2) the target buffer level is changeable in the GOP, at the end of each GOP( five P-frames or B-frames), the target buffer level is linearly reduced from 1/2 to 1/4 of buffer size, to other frames, the target buffer level is set to 1/2 of buffer size: 3 ) a selective and judicious use of the reduced resolution mode, in addition to a modulation of the quantization scale parameter, is to control the average long term bit rate. Experimental results with different video sequences of varied complexity, encoded at low bit rates show better efficacy of the proposed algorithm than MPEG-4 Q2 rate control scheme, and the experimental results also show that the improved algorithm has significantly reduced the number of frame skipping, increased the overall PSNR, and improved the perceptual quality.  相似文献