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一种度量目标散射随机性的新参数
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作者 陈强 蒋咏梅 匡纲要 《信号处理》 CSCD 北大核心 2010年第9期1300-1305,共6页
针对现有目标散射随机性度量参数运算量偏大、度量不合理等问题,本文提出了一种基于目标散射回波极化度的度量目标散射随机性的新参数——散射随机系数。在分析散射回波极化度与散射随机性之间的相互关系的基础上,首先给出了基于散射回... 针对现有目标散射随机性度量参数运算量偏大、度量不合理等问题,本文提出了一种基于目标散射回波极化度的度量目标散射随机性的新参数——散射随机系数。在分析散射回波极化度与散射随机性之间的相互关系的基础上,首先给出了基于散射回波极化度的散射随机系数定义。然后通过分析新参数随着目标各向异性和散射阶次的变化情况,阐明新参数在度量目标散射随机性方面是合理的。最后结合San Francisco和Flevoland两地区的实测极化数据验证了新参数在度量目标散射随机性方面的有效性,与极化散射熵的对比实验结果表明了在大数据量的POLSAR图像散射分类应用中新参数运算效率更高。 展开更多
关键词 目标随机性 极化度 极化SAR图像分类 雷达极化
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A meta-analytic review of the approach-avoidance achievement goals and performance relationships in the sport psychology literature 被引量:2
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作者 Marc Lochbaum Jarrett Gottardy 《Journal of Sport and Health Science》 SCIE 2015年第2期164-173,共10页
Purpose: To summarize the approach-avoidance achievement goal and performance in the sport psychology literature.Methods: A total of 17 published studies, two of which provided two samples, were located. Accepted me... Purpose: To summarize the approach-avoidance achievement goal and performance in the sport psychology literature.Methods: A total of 17 published studies, two of which provided two samples, were located. Accepted meta-analytic procedures were used with Hedges g as the effect size metric. From the 17 studies, 73 effect sizes were calculated.Results: Results based on a random effects model indicated that the performance goal contrast had the largest facilitative impact on performance followed by the mastery and performance approach goals. Both of the avoidance goals performance and mastery had small non-significant and detrimental effects on performance. The homogeneity statistics revealed significant heterogeneity for the approach and avoidance performance goals. Categorical moderator variables were examined for study sex composition(male, female, or mixed), mean age of sample(〈18 years or 18 years), study setting(lab or naturalistic), and nature of performance variable(objective or subjective).Conclusion: The performance goal contrast holds value for sport performance research. Contrary to approach-avoidance predictions, the mastery-approach goal and performance effect size was significant and of equal magnitude as the performance approach goal and performance effect size. Thus, future research should closely test the efficacy of both the mastery- and performance contrasts in impacting performance of sport tasks. Last, the significant effect sizes reported in this review are in stark contrast to contemporary meta-analytic findings in education.Differences in the approach-avoidance goals in sport and education relative to performance should be researched further. 展开更多
关键词 Mastery approach goals Performance approach goals Performance enhancement Performance goal contrast
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