期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
基于GA-BP神经网络的砌体结构拆除造价预测
1
作者 王勃 杨占秋 董丽欣 《吉林建筑大学学报》 CAS 2021年第5期7-11,共5页
精准快速地进行造价预测对于拆除工程的招投标决策具有重要意义.我国目前待拆除建筑物多为砌体结构.为寻求砌体结构拆除工程造价的高效预测方法,本文首先分析了反向传播(BP)神经网络和遗传算法(GA)的优势和缺点.通过利用GA的全局搜索最... 精准快速地进行造价预测对于拆除工程的招投标决策具有重要意义.我国目前待拆除建筑物多为砌体结构.为寻求砌体结构拆除工程造价的高效预测方法,本文首先分析了反向传播(BP)神经网络和遗传算法(GA)的优势和缺点.通过利用GA的全局搜索最优性能,调节BP神经网络的权值阈值,改善BP神经网络容易陷入局部最小值且收敛速度慢的缺点,提出了优化砌体结构拆除工程造价的预测模型.针对拆除工程的特点,选取8个主要参数,利用50组样本数据进行训练预测.结果表明,优化后的预测模型具有较好的泛化能力和良好的稳定性,可为砌体结构拆除工程造价预测方面提供参考. 展开更多
关键词 砌体结构 反向传播(BP)神经网络 遗传算法 拆除工程 造价预测
下载PDF
Study for Interrelationship Between Human Herpes Simplex Virus Type 2 and Leukemia
2
作者 Liu Jian-jun Guo Guang-song +1 位作者 Xu Shun-xian yang zhan-qiu 《Wuhan University Journal of Natural Sciences》 EI CAS 2000年第3期366-372,共7页
Two different strains of human herpes simplex virus type 2 (HHSV-2) and /or murine leukemia virus (MLV) were inoculated into newborn mice. In mice of mixed infection with MLV plus HHSV-2(333) or MLV plus HHSV-2(Wu)inc... Two different strains of human herpes simplex virus type 2 (HHSV-2) and /or murine leukemia virus (MLV) were inoculated into newborn mice. In mice of mixed infection with MLV plus HHSV-2(333) or MLV plus HHSV-2(Wu)incidences of leukemia were respectively 79.16% and 75.00%,and in those inoculated with MLV alone were 41.02% and 44.74% in the experiment for 3 months. The differences of incidences between the two conditions were highly significant (p<0.01). On the contrary, no leukemia was detected in mice that were inoculated with HHSV-2 (333) or HHSV-2 (Wu) alone and in controls. Leukemia developing time of mice infected with two viruses was earlier than with MLV alone. It is obvious that the induction of murine leukemia resulted from infection of MLV and was independent of HHSV-2 (333) and HHSV-2(Wu). Both risen incidences and shortened latencies of murine leukemia were in close relationship with infection of HHSV-2(333) and HHSV-2(Wu). 展开更多
关键词 MLV LEUKEMIA HSV-2 Mouse
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部