Diameter distribution models play an important role in forest inventories,growth prediction,and management.The Weibull probability density function is widely used in forestry.Although a number of methods have been pro...Diameter distribution models play an important role in forest inventories,growth prediction,and management.The Weibull probability density function is widely used in forestry.Although a number of methods have been proposed to predict or recover the Weibull distribution,their applicability and predictive performance for the major tree species of China remain to be determined.Trees in sample plots of three even-aged coniferous species(Larix olgensis,Pinus sylvestris and Pinus koraiensis)were measured both in un-thinned and thinned stands to develop parameter prediction models for the Weibull probability density function.Ordinary least squares(OLS)and maximum likelihood regression(MLER),as well as cumulative distribution function regression(CDFR)were used,and their performance compared.The results show that MLER and CDFR were better than OLS in predicting diameter distributions of tree plantations.CDFR produced the best results in terms of fitting statistics.Based on the error statistics calculated for different age groups,CDFR was considered the most suitable method for developing prediction models for Weibull parameters in coniferous plantations.展开更多
针对多输入单输出(MISO,multiple input single output)通信系统的STBC-OFDM信号盲识别问题,提出基于OFDM块的改进Kolmogorov-Smirnov(K-S)检测方法。该方法首先对MISO通信系统的STBC-OFDM信号建模;然后利用STBC-OFDM信号编码矩阵的相关...针对多输入单输出(MISO,multiple input single output)通信系统的STBC-OFDM信号盲识别问题,提出基于OFDM块的改进Kolmogorov-Smirnov(K-S)检测方法。该方法首先对MISO通信系统的STBC-OFDM信号建模;然后利用STBC-OFDM信号编码矩阵的相关性,构造不同时延向量下STBC-OFDM接收信号OFDM块的经验函数作为特征函数;最后通过改进K-S检测方法检验经验分布函数之间的距离盲识别STBC-OFDM信号。该方法不需要噪声信息、调制信息和信道系数,适合非合作通信场合。理论分析和实验验证了该方法的可行性。展开更多
基金supported by the Natural Science Foundation of China(32071758 and U21A20244)the Fundamental Research Funds for the Central Universities of China(No.2572020BA01)。
文摘Diameter distribution models play an important role in forest inventories,growth prediction,and management.The Weibull probability density function is widely used in forestry.Although a number of methods have been proposed to predict or recover the Weibull distribution,their applicability and predictive performance for the major tree species of China remain to be determined.Trees in sample plots of three even-aged coniferous species(Larix olgensis,Pinus sylvestris and Pinus koraiensis)were measured both in un-thinned and thinned stands to develop parameter prediction models for the Weibull probability density function.Ordinary least squares(OLS)and maximum likelihood regression(MLER),as well as cumulative distribution function regression(CDFR)were used,and their performance compared.The results show that MLER and CDFR were better than OLS in predicting diameter distributions of tree plantations.CDFR produced the best results in terms of fitting statistics.Based on the error statistics calculated for different age groups,CDFR was considered the most suitable method for developing prediction models for Weibull parameters in coniferous plantations.
文摘针对多输入单输出(MISO,multiple input single output)通信系统的STBC-OFDM信号盲识别问题,提出基于OFDM块的改进Kolmogorov-Smirnov(K-S)检测方法。该方法首先对MISO通信系统的STBC-OFDM信号建模;然后利用STBC-OFDM信号编码矩阵的相关性,构造不同时延向量下STBC-OFDM接收信号OFDM块的经验函数作为特征函数;最后通过改进K-S检测方法检验经验分布函数之间的距离盲识别STBC-OFDM信号。该方法不需要噪声信息、调制信息和信道系数,适合非合作通信场合。理论分析和实验验证了该方法的可行性。
