Holographic multiple-input multiple-output(HMIMO)has become an emerging technology for achieving ultra-high frequency spectral efficiency and spatial resolution in future wireless systems.The increasing antenna apertu...Holographic multiple-input multiple-output(HMIMO)has become an emerging technology for achieving ultra-high frequency spectral efficiency and spatial resolution in future wireless systems.The increasing antenna aperture leads to a more significant characterization of the spherical wavefront in near-field communications in HMIMO scenarios.Beam training as a key technique for wireless communication is worth exploring in this near-field scenario.Compared with the widely researched far-field beam training,the increased dimensionality of the search space for near-field beam training poses a challenge to the complexity and accuracy of the proposed algorithm.In this paper,we introduce several typical near-field beam training methods:exhaustive beam training,hierarchical beam training,and multi-beam training that includes equal interval multi-beam training and hash multi-beam training.The performances of these methods are compared through simulation analysis,and their effectiveness is verified on the hardware testbed as well.Additionally,we provide application scenarios,research challenges,and potential future research directions for near-field beam training.展开更多
【目的】基于协方差估计的多因变量回归(multivariate regression with covariance estimation,MRCE)模型进行多性状QTL定位分析,为动植物数量性状基因定位提供理论参考。【方法】构建适用QTL定位的MRCE模型,设计3个模拟试验对模型进行...【目的】基于协方差估计的多因变量回归(multivariate regression with covariance estimation,MRCE)模型进行多性状QTL定位分析,为动植物数量性状基因定位提供理论参考。【方法】构建适用QTL定位的MRCE模型,设计3个模拟试验对模型进行检验,通过计算机生成基因型和2个相关性状的表型值,并用2组数据对模型进行实际应用,其中一组为水稻DH群体数据,选自qtlnetwork软件;另一组为水稻永久F群体数据,由珍汕97×明恢63,含有210个株系的重组自交系(RIL)群体随机交配生成,分析MRCE模型在以上2组数据多性状QTL定位中的应用效果。【结果】用MRCE模型进行QTL定位的模拟试验结果表明,遗传变异所占方差比越大,相关系数绝对值越大,遗传率越大,则功效越好,估计值越接近效应值。MRCE的QTL定位应用结果显示,从水稻DH群体中识别出8个QTL与ph6性状有关,6个QTL与ph8性状有关;从1998年水稻永久F群体数据中识别出3个QTL与穗粒数相关,10个QTL与粒质量相关;从1999年数据识别出3个QTL与穗粒数相关,6个QTL与粒质量相关。【结论】利用MRCE模型进行多性状QTL定位是可行的。展开更多
Based on the macrofauna data(2008-2011) in Xiaoqing River estuary and its adjacent sea, Laizhou Bay of Bohai Sea, China, the AZTI Marine Biotic Index(AMBI) and Multivariate AMBI(M-AMBI) were used for benthic habitat q...Based on the macrofauna data(2008-2011) in Xiaoqing River estuary and its adjacent sea, Laizhou Bay of Bohai Sea, China, the AZTI Marine Biotic Index(AMBI) and Multivariate AMBI(M-AMBI) were used for benthic habitat quality(BHQ) assessment. Results showed that BHQ presented an obvious trend of improvement along the direction of stream channel and river mouth, and in the coastal areas. AMBI and M-AMBI were significantly related to environmental pressure gradient data. Therefore, the two indices can well indicate BHQ in the studied area. However, there were significant differences between results of the two indices. In the cases of low taxa number and high abundance of single species, AMBI might overestimate BHQ. We thus adjusted its thresholds to solve this problem. And M-AMBI might overestimate BHQ when benthic assemblage was dominated by the opportunistic species. Then we could raise the weight of AMBI in the calculation of M-AMBI to handle the problem.展开更多
Vocabulary plays an irreplaceable role in a language.As an important carrier to record foreign cultures in vocabulary,loanwords are widely used in all aspects of society.Modern Chinese Dictionary includes loanwords fr...Vocabulary plays an irreplaceable role in a language.As an important carrier to record foreign cultures in vocabulary,loanwords are widely used in all aspects of society.Modern Chinese Dictionary includes loanwords from a variety of languages from the perspective of universal use.This paper takes the loanwords in Modern Chinese Dictionary(7th Edition)as the closed corpus,and analyzes the etymology,structure,word length,and other aspects while making blanket statistics on the loanwords.The representative words are investigated by word frequency and described from multiple perspectives.展开更多
文摘Holographic multiple-input multiple-output(HMIMO)has become an emerging technology for achieving ultra-high frequency spectral efficiency and spatial resolution in future wireless systems.The increasing antenna aperture leads to a more significant characterization of the spherical wavefront in near-field communications in HMIMO scenarios.Beam training as a key technique for wireless communication is worth exploring in this near-field scenario.Compared with the widely researched far-field beam training,the increased dimensionality of the search space for near-field beam training poses a challenge to the complexity and accuracy of the proposed algorithm.In this paper,we introduce several typical near-field beam training methods:exhaustive beam training,hierarchical beam training,and multi-beam training that includes equal interval multi-beam training and hash multi-beam training.The performances of these methods are compared through simulation analysis,and their effectiveness is verified on the hardware testbed as well.Additionally,we provide application scenarios,research challenges,and potential future research directions for near-field beam training.
文摘【目的】基于协方差估计的多因变量回归(multivariate regression with covariance estimation,MRCE)模型进行多性状QTL定位分析,为动植物数量性状基因定位提供理论参考。【方法】构建适用QTL定位的MRCE模型,设计3个模拟试验对模型进行检验,通过计算机生成基因型和2个相关性状的表型值,并用2组数据对模型进行实际应用,其中一组为水稻DH群体数据,选自qtlnetwork软件;另一组为水稻永久F群体数据,由珍汕97×明恢63,含有210个株系的重组自交系(RIL)群体随机交配生成,分析MRCE模型在以上2组数据多性状QTL定位中的应用效果。【结果】用MRCE模型进行QTL定位的模拟试验结果表明,遗传变异所占方差比越大,相关系数绝对值越大,遗传率越大,则功效越好,估计值越接近效应值。MRCE的QTL定位应用结果显示,从水稻DH群体中识别出8个QTL与ph6性状有关,6个QTL与ph8性状有关;从1998年水稻永久F群体数据中识别出3个QTL与穗粒数相关,10个QTL与粒质量相关;从1999年数据识别出3个QTL与穗粒数相关,6个QTL与粒质量相关。【结论】利用MRCE模型进行多性状QTL定位是可行的。
基金supported by the NSFC-Shandong Joint Fund for Marine Science Research Centers (Grant No. U1406404)the National Marine Public Welfare Research Project of China (Grant No. 201405007)
文摘Based on the macrofauna data(2008-2011) in Xiaoqing River estuary and its adjacent sea, Laizhou Bay of Bohai Sea, China, the AZTI Marine Biotic Index(AMBI) and Multivariate AMBI(M-AMBI) were used for benthic habitat quality(BHQ) assessment. Results showed that BHQ presented an obvious trend of improvement along the direction of stream channel and river mouth, and in the coastal areas. AMBI and M-AMBI were significantly related to environmental pressure gradient data. Therefore, the two indices can well indicate BHQ in the studied area. However, there were significant differences between results of the two indices. In the cases of low taxa number and high abundance of single species, AMBI might overestimate BHQ. We thus adjusted its thresholds to solve this problem. And M-AMBI might overestimate BHQ when benthic assemblage was dominated by the opportunistic species. Then we could raise the weight of AMBI in the calculation of M-AMBI to handle the problem.
文摘Vocabulary plays an irreplaceable role in a language.As an important carrier to record foreign cultures in vocabulary,loanwords are widely used in all aspects of society.Modern Chinese Dictionary includes loanwords from a variety of languages from the perspective of universal use.This paper takes the loanwords in Modern Chinese Dictionary(7th Edition)as the closed corpus,and analyzes the etymology,structure,word length,and other aspects while making blanket statistics on the loanwords.The representative words are investigated by word frequency and described from multiple perspectives.
