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
机构地区:[1]天津大学环境科学与工程学院,天津300072 [2]大连理工大学建筑与艺术学院,大连116024
出 处:《上海环境科学》2010年第2期52-54,65,共4页Shanghai Environmental Sciences
基 金:中国博士后科学基金项目,编号:20090450764;辽宁省教育厅项目,编号:2009B043
摘 要:因夜间天空亮度分布具有非线性变化特点,故引入神经网络算法,建立基于时间序列的夜天空亮度预测模型,夜天空亮度预测模型可为城市光污染防治提供评价依据。文章对神经网络的原理进行了论述,建立了基于时间序列预测模型。以测试数据为训练样本集,基于MATLAB(矩阵实验室,Matrix Laboratory的简称),采用改进的BP算法(误差反向传播算法)对网络进行学习训练,并对存在的误差进行了分析。基于时间序列BP神经网络的夜天空预测模型,当隐含层神经元数目为5,训练函数为L-M优化算法(trainlm)时,最大绝对误差可达到0.003 6 cd/m2,最大相对误差达到2.361 4%。结果表明,模型的运行结果与试验数据比较吻合,输出与目标矢量之间相关性也较好。The purpose of a night sky brightness prediction model was for evaluation and prevention of urban light pollution.Owing to the nonlinear distribution of night sky brightness,the BP neural network algorithm based on time series theory was introduced.The principle of neural network was discussed and the prediction model based on time series theory was established.The test data as training samples were trained by improved BP algorithm with MATLAB(short for Matrix Laboratory),and their error were analyzed.When the number of hidden neurons was five and training function was L-M optimising algorithm called trainlm,the maximal absolute error could reach 0.0036 candela per square metre while the maximal relative error being 2.361 4%.It has shown that the modelling results were consistent with the experiment data,and the correlation between the outputs and target vectors was fairly satisfactory.
分 类 号:TP273[自动化与计算机技术—检测技术与自动化装置]
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:216.73.216.249