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求解大样本核主成分分析模型的Lanczos算法 被引量:8
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作者 陈永良 林楠 李学斌 《吉林大学学报(地球科学版)》 EI CAS CSCD 北大核心 2010年第1期222-226,共5页
求解核主成分分析模型的技术关键是确定核矩阵端部的较大特征对。把求解大规模对称矩阵端部特征对问题的基本方法——Lanczos算法应用于核主成分分析模型的求解,设计了大样本核主成分分析模型求解的实用算法。在clapack和nu-TRLan两个... 求解核主成分分析模型的技术关键是确定核矩阵端部的较大特征对。把求解大规模对称矩阵端部特征对问题的基本方法——Lanczos算法应用于核主成分分析模型的求解,设计了大样本核主成分分析模型求解的实用算法。在clapack和nu-TRLan两个软件包的基础上,开发了大样本核主成分分析模型求解算法的VC++程序。用高光谱遥感图像数据进行模型求解算法的应用试验研究,证明了大样本核主成分分析模型求解算法的实用性。 展开更多
关键词 大样本 核主成分分析 LANCZOS算法 thick-重启动策略
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平地无风条件下蒙古栎阔叶床层的火行为Ⅲ.火线强度、可燃物消耗和燃烧效率分析及预测模型 被引量:10
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作者 张吉利 刘礴霏 +2 位作者 邸雪颖 褚腾飞 金森 《应用生态学报》 CAS CSCD 北大核心 2013年第12期3381-3390,共10页
以东北地区针阔混交林重要建群种和伴生种蒙古栎为对象,在平地无风条件下进行室内点烧试验,分析含水率、载量和厚度对蒙古栎凋落叶床层火线强度、消耗量和燃烧效率的影响,并对相关模型进行了验证.结果表明:含水率、载量和床层厚度对蒙... 以东北地区针阔混交林重要建群种和伴生种蒙古栎为对象,在平地无风条件下进行室内点烧试验,分析含水率、载量和厚度对蒙古栎凋落叶床层火线强度、消耗量和燃烧效率的影响,并对相关模型进行了验证.结果表明:含水率、载量和床层厚度对蒙古栎凋落叶床层火线强度、消耗量和燃烧效率均有显著影响,并且3个指标之间存在交互作用.在已有模型中,Byram模型需参数调整后方可用于本地凋落叶可燃物,其重新估计的α、β拟合值分别为98.009和1.099,得到的预测值均方根误差为8.676 kW·m-1,平均相对误差为21.0%,R2为0.745.对Albini提出的燃烧效率模型参数a、b的重新估计值分别为0.069和0.169,得到的预测值均在93.0%以上,绝大多数偏高.Consume模型适用性较强.新建立的火线强度、消耗量和燃烧效率的一般线性模型调整后的R2分别为0.82、0.73和0.53,均方根误差分别为8.266 kW·m-1、0.081 kg·m-2和0.203.在低强度地表火中,细小可燃物可能不会被完全消耗,现有一些系统中将凋落叶和细小可燃物按全部消耗处理,将高估碳的释放量. 展开更多
关键词 火线强度 消耗量 含水率 载量床层厚度 预测模型 蒙古栎
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Simulation and Validation of the Aerosol Optical Thickness over China in 2006
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作者 张华 张敏 +2 位作者 崔振雷 王跃思 辛金元 《Acta meteorologica Sinica》 SCIE 2012年第3期330-344,共15页
The Model of Atmospheric Transport and Chemistry (MATCH) developed by the US National Center for Atmospheric Research (NCAR) was used to calculate the aerosol optical thickness (AOT) over China in 2006, with emi... The Model of Atmospheric Transport and Chemistry (MATCH) developed by the US National Center for Atmospheric Research (NCAR) was used to calculate the aerosol optical thickness (AOT) over China in 2006, with emission source data of the Intercontinental Chemical Transport Experiment Phase B (INTEX-B) and NCEP/NCAR reanalysis data as inputs. The simulation results of AOT were then validated with obser- vational data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Chinese Sun Hazemeter Network (CSHNET), Aerosol Robotics Network (AERONET), and China Aerosol Remote Sensing Network (CARSNET) at more than 30 stations over China. The comparison results indicated that the high values of AOT in the areas such as the Sichuan basin and East and South China and the low values of AOT over the Tibetan Plateau and Northwest and Northeast China were reasonably simulated by the MATCH. This model tended to underestimate the AOT values in high-aerosol-loading areas but overestimate the AOT val- ues in less polluted areas because there are still large uncertainties in the expression of emission sources, the description of the optical properties of aerosols, the treatment of cloud and precipitation, and the selection of grid resolution. The modeling results were consistent with the CSHNET, CARSNET, AERONET, and MODIS data in most parts of China, and the correlation coefficient of the monthly mean AOT between the model and the observation was 0.79 with CSHNET data at 23 stations, 0.51 with MODIS data, and 0.88 with data at 3 CARSNET stations and 2 other stations. All of them passed the significance test with c 〈 0.0001. The results demonstrated that the MATCH has the ability to simulate the characteristics of the AOT distribution and its seasonal variation over China. 展开更多
关键词 Model of Atmospheric Transport and Chemistry (MATCH) AEROSOL aerosol optical thick-ness (AOT) Intercontinental Chemical Transport Experiment Phase B (INTEX-B) AerosolRobotics Network (AERONET) Chinese Sun Hazemeter Network (CSHNET)
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