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2DPCA+2DLDA和改进的LPP相结合的人脸识别算法 被引量:8
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作者 李球球 杨恢先 +2 位作者 奉俊鹏 蔡勇勇 翟云龙 《计算机工程与应用》 CSCD 北大核心 2015年第21期199-204,共6页
针对局部保持投影(LPP)算法无监督且只保留局部信息的特性,提出一种2DPCA+2DLDA和改进的LPP相结合的人脸识别算法。将训练集样本用2DPCA+2DLDA算法进行投影,保留数据整体空间信息和分类信息;引入类内、类间信息对LPP算法的关系矩阵进行... 针对局部保持投影(LPP)算法无监督且只保留局部信息的特性,提出一种2DPCA+2DLDA和改进的LPP相结合的人脸识别算法。将训练集样本用2DPCA+2DLDA算法进行投影,保留数据整体空间信息和分类信息;引入类内、类间信息对LPP算法的关系矩阵进行优化,使LPP成为有监督的非线性学习方法,采用改进的LPP(ILPP)算法对训练集图像进行二次投影,提取样本的局部流形信息,并作为人脸识别信息进行鉴别。在Yale和ORL人脸库的测试结果验证了该方法的有效性。 展开更多
关键词 人脸识别 二维主成分分析+二维线性判别分析(2DPCA+2DLDA) 局部保持投影(LPP) 改进的局部保持投 影(1LPP) 局部流形信息
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Engineering cellular dephosphorylation boosts(+)-borneol production in yeast 被引量:2
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作者 Haiyan Zhang Peng Cai +8 位作者 Juan Guo Jiaoqi Gao Linfeng Xie Ping Su Xiaoxin Zhai Baolong Jin Guanghong Cui Yongjin J.Zhou Luqi Huang 《Acta Pharmaceutica Sinica B》 2025年第2期1171-1182,共12页
(+)-Borneol,the main component of"Natural Borneol"in the Chinese Pharmacopoeia,is a high-end spice and precious medicine.Plant extraction cannot meet the increasing demand for(+)-borneol,while microbial bios... (+)-Borneol,the main component of"Natural Borneol"in the Chinese Pharmacopoeia,is a high-end spice and precious medicine.Plant extraction cannot meet the increasing demand for(+)-borneol,while microbial biosynthesis offers a sustainable supply route.However,its production was extremely low compared with other monoterpenes,even with extensively optimizing the mevalonate pathway.We found that the key challenge is the complex and unusual dephosphorylation reaction of bornyl diphosphate(BPP),which suffers the side-reaction and the competition from the cellular dephosphorylation process,especially lipid metabolism,thus limiting(+)-borneol synthesis.Here,we systematically optimized the dephosphorylation process by identifying,characterizing phosphatases,and balancing cellular dephosphorylation metabolism.For the first time,we identified two endogenous phosphatases and seven heterologous phosphatases,which significantly increased(+)-borneol production by up to 152%.By engineering BPP dephosphorylation and optimizing the MVA pathway,the production of(+)-borneol was increased by 33.8-fold,which enabled the production of 753 mg/L under fed-batch fermentation in shake flasks,so far the highest reported in the literature.This study showed that rewiring dephosphorylation metabolism was essential for high-level production of(+)-borneol in Saccharomyces cerevisiae,and balancing cellular dephosphorylation is also helpful for efficient biosynthesis of other terpenoids since all whose biosynthesis involves the dephosphorylation procedure. 展开更多
关键词 BORNEOL MONOTERPENE lpp1 DPP1 Nudix hydrolase PHOSPHATASE
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