期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
基于灰色粗糙集与BP神经网络的设备故障预测 被引量:17
1
作者 郭宇 杨育 《计算机应用研究》 CSCD 北大核心 2017年第9期2642-2645,共4页
为更有效地预测设备故障,提出一种基于灰色粗糙集与BP神经网络的设备故障预测模型。用灰色关联分析和粗糙集理论分别对二维故障决策表进行横向和纵向两个维度的约简,将冗余的数据和属性去掉,并将约简后的数据输入到BP神经网络,预测设备... 为更有效地预测设备故障,提出一种基于灰色粗糙集与BP神经网络的设备故障预测模型。用灰色关联分析和粗糙集理论分别对二维故障决策表进行横向和纵向两个维度的约简,将冗余的数据和属性去掉,并将约简后的数据输入到BP神经网络,预测设备故障。最后以地铁信号设备故障预测为例进行实例验证,结果表明该模型预测误差更小,预测准确率更高。 展开更多
关键词 灰色关联分析 粗糙集 BP神经网络 约简 故障预测
在线阅读 下载PDF
4个香菇品种的AFLP分子标记研究
2
作者 雷萍 张文隽 +3 位作者 吴亚召 王磊 赵玉鹏 任宏飞 《现代农业科技》 2019年第9期47-48,52,共3页
试验以香菇LB-21、香菇L808、香菇215和香菇B15-1等4个品种为研究材料,采用AFLP分子标记技术分析其遗传多样性。结果表明,4个香菇品种之间的遗传相似性系数变化范围为0.669 5~0.878 7;UPGMA法聚类分析发现,4个品种分为2组,香菇LB-21与... 试验以香菇LB-21、香菇L808、香菇215和香菇B15-1等4个品种为研究材料,采用AFLP分子标记技术分析其遗传多样性。结果表明,4个香菇品种之间的遗传相似性系数变化范围为0.669 5~0.878 7;UPGMA法聚类分析发现,4个品种分为2组,香菇LB-21与香菇B15-1亲缘关系较近,遗传相似性系数为0.874 5,香菇L808与香菇215亲缘关系较近,遗传相似性系数为0.878 7。 展开更多
关键词 香菇 AFLP分子标记 遗传多样性 聚类分析
在线阅读 下载PDF
Prognosis of HER2 over-expressing gastric cancer patients with liver metastasis 被引量:17
3
作者 Hai-Zhen Dang Yang Yu Shun-Chang Jiao 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第19期2402-2407,共6页
AIM:To study the risk factors for liver metastasis and the prognosis in patients with human epidermal growth factor receptor 2(HER2) over-expressing gastric cancer(GC).METHODS:A total of 84 GC patients recruited from ... AIM:To study the risk factors for liver metastasis and the prognosis in patients with human epidermal growth factor receptor 2(HER2) over-expressing gastric cancer(GC).METHODS:A total of 84 GC patients recruited from the General Hospital of the People's Liberation Army(PLA) between 2003 and 2010 were randomly enrolled in this study.HER2 expression was detected by immunohistochemistry in 84 GC patients with liver metastases.The study group consisted of 66 men and 18 women,with an average age of 54 years(range:19-74 years).Liver metastasis was diagnosed by magnetic resonance imaging or computed tomography.Patients were followed-up and predictive factors of liver metastasis were evaluated.RESULTS:The median follow-up period was 47 mo(range:6-85 mo).The characteristics of 35(25.7%) patients with HER2 over-expression of liver metastatic GC are presented.HER2 over-expression was detected in 23 out of 49(46.9%) patients with intestinal GC,and 9 out of 35(25.7%) patients with diffuse GC.29 out of 59(49.2%) patients aged < 60 years were HER2positive,while 8 out of 25(32%) patients aged ≥ 60 were HER2-positive;a significant difference(P < 0.05).Univariate analysis(log-rank test) showed that HER2 over-expression,sex,Lauren classification,differentiation and disease-free interval were correlated with poor survival(P < 0.05).Survival analysis with a survival curve showed that HER2 over-expression was significantly relevant,with a reduced survival time in GC patients with liver metastases(P < 0.01).2-year survival was not associated with the patient's age.A diseasefree survival longer than 12 mo has a significant association with extended overall survival(OS) in GC patients with liver metastases.The median survival time after the diagnosis of liver metastases was 18 mo [95% confidence interval(CI):9.07-26.94] among HER2 positive GC patients with liver metastases.In comparison,for 49(69.4%) out of 84 HER2 negative patients with liver metastatic GC,the median survival time was 47 mo(95% CI:19.37-74.63).In patients with HER2 positive liver metastatic GC,the median OS was significantly shorter than in HER2 negative patients(median,20.32 mo;95% CI:16.51-24.13 vs median,50.14 mo;95% CI:37.83-62.45;P < 0.01).CONCLUSION:HER2 over-expressing GC patients with liver metastases have a poor prognosis.Overall survival was significantly lower in HER2 positive patients.HER2overexpression is correlated with a lower survival rate. 展开更多
关键词 Human epidermal growth factor receptor 2 OVEREXPRESSION Gastric cancer Liver metastasis Over-all survival PROGNOSIS
在线阅读 下载PDF
焊接残余应力对矩形薄板非线性因素忽略条件的影响 被引量:1
4
作者 唐果 李志高 +1 位作者 舒慧 龚帅 《机械》 2020年第9期40-43,共4页
以具有对接焊接残余应力的非线性矩形薄板为研究对象,根据非线性振动理论,研究得出了在薄板和薄板结构的设计和计算分析时,具有焊接残余应力矩形簿板非线性因素忽略的条件和矩形薄板非线性因素忽略的分界线;通过分析获得了矩形薄板的固... 以具有对接焊接残余应力的非线性矩形薄板为研究对象,根据非线性振动理论,研究得出了在薄板和薄板结构的设计和计算分析时,具有焊接残余应力矩形簿板非线性因素忽略的条件和矩形薄板非线性因素忽略的分界线;通过分析获得了矩形薄板的固有频率在一定的范围内,可以不考虑非线性因素;不考虑非线性因素的范围随残余应力的增大而增大;等值的增大残余应力,随残余应力增大不考虑非线性因素的区域的增大越来越快等结论。提出了在要求允许的前提下,通过提高构件残余应力增加不考虑非线性因素的固有频率范围的方法。 展开更多
关键词 焊接残余应力 矩形薄板 非线性因素 忽略条件
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部