检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:宋云龙[1] 张万年[1] 季海涛[1] 盛春泉[1] 周有骏[1] 朱驹[1] 吕加国[1]
机构地区:[1]中国人民解放军第二军医大学药学院,上海200433
出 处:《中国药学杂志》2003年第1期60-63,共4页Chinese Pharmaceutical Journal
基 金:"973"国家重点基础研究项目子项目 (G19980 5110 4 );国家自然科学基金 ( 39970 874 )
摘 要:目的 采用神经网络方法对喜树碱类抗肿瘤药物构效关系进行考察。方法 采用主成分分析 (principalcomponentanal ysis,PCA)预处理输入层数据和Levenberg Marquardt规则训练网络。 结果 改进的神经网络PCANN所得结果预测性能较强(R2 值为 0 .878) ,明显优于GA PLS结果 (R2 值为 0 .684)。结论 本研究表明经过改进后的神经网络不仅训练速度大大提高 ,而且所得结果统计意义显著。这为下一步合理设计。OBJECTIVE: Artificial neural networks (ANNs) were applied into the QSARs of 21 antitumor camptothecin derivatives. METHOD: Principal component analysis (PCA) was used to preprocess training data set to reduce the dimension of input vectors and orthogonalize the components of input vectors. Artificial neural networks were trained with Levenberg-Marquardt rule that has been proved to have a fastest convergence for modest network. RESULTS: The results obtained by the PCANN method (R2 = 0.878) seemed to be much better than those by GA-PLS (R2 = 0.684). CONCLUSION: It was shown that modified artificial neural network - PCANN (Principal Component Analysis/Artificial Neural Network) had a faster convergence and the resulting model had good predictive ability. This will benefit future design and synthesis of novel highly potent antitumor camptothecin derivatives.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.166