检索结果-南通市图书馆

Real-time probabilistic sediment concentration forecasting using integrated dynamic network and error distribution heterogeneity

引用

International Journal of Sediment Research 2022年第6期37卷 766-779页

作者： Fangzheng Zhao Xinyu Wan Xiaolin Wang qingyang wu Yan wu College of Hydrology and Water Resources Hohai University

Sediment forecasting at a dam site is important for the operation and management of water and sediment in a reservoir. However, the forecast results generally have some uncertainties, which may hinder the operation of the dam. In this study, a real-time sediment concentration probabilistic forecasting model is proposed based on a dynamic network model. Under this framework, the Elman neural network(ENN) and nonlinear auto-regressive with exogenous inputs(NARX) neural network models were established for sediment concentration forecasting with different lead times. A hybrid algorithm, which combined the Levenberg-Marquardt algorithm and real-time recurrent learning, was used to train the model. Using the aforementioned method, the sediment concentration was forecast for at the Sanmenxia Dam, China, and, subsequently, the forecast results were evaluated. Among the selected lead time, the results at 5 h exhibited the highest accuracy and practical significance. Compared with the ENN model,the sediment concentration peak error using the NARX neural network was reduced by 4.5%, and the sediment yield error was reduced by 0.043%. Therefore, the NARX neural network was selected as the deterministic sediment forecasting model. Additionally, the probability density function of the sediment concentration was derived based on the heterogeneity of the error distribution, and the sediment concentration interval, with different confidence levels, expected values, and median values, was forecast. The Nash-Sutcliffe coefficient of efficiency for the sediment concentration, as forecasted based on the median value, was the highest(0.04 higher than that using a deterministic model), whereas the error of the sediment concentration peak and sediment yield remained unaltered. These results indicated the accuracy and superiority of the proposed real-time sediment probabilistic forecasting hybrid model.

关键词： Dynamic network Hybrid learning algorithm Error distribution heterogeneity Probability density function Sediment concentration forecasting NARX neural network

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Effects of phenanthrene on hepatic enzymatic activities in tilapia(Oreochromis niloticus ♀×*** ♂)

引用

Journal of Environmental Sciences 2009年第6期21卷 854-857页

作者： XU Wenju LI Yuanyou wu qingyang WANG Shuqi ZHENG Huaiping LIU Wenhua Marine Biology Institute of Shantou University Shantou Guangdong 515063 China Biology Department of Hanshan Normal University Chaozhou 521041 China

The effects of phenanthrene（Phe） on hepatosomatic index（HSI） and hepatic enzymatic activities in hybrid tilapia（Oreochromis niloticus ♀× *** ♂） were investigated via the static freshwater exposure at dosage of 50,100,and 400 μg/L for 4-14 *** with the control group,HSI was significantly decreased（P 〈 0.05） at 400 μg/L at day *** enzymatic activities（P 〈 0.05） were observed for catalase（CAT）,glutathione peroxidase（GPx） and superoxide dismutase（SOD） at either 100 or 400 μg/L at day 8 and 14,as well as for CAT at 50 μg/L at day 14,except for GPx at 400 μg/L at day *** O-deethylase（EROD） activity was significantly increased（P 〈 0.05） at all dosage at day 4 as well as at 50 μg/L at day 8,but significantly decreased at either 100 or 400 μg/L at day 14（P 〈 0.05）.Glutathione-S-transferase（GST） activity was not *** results suggest that CAT,GPx,SOD and EROD,as well as HSI in tilapia may be used as the biomarkers or indexes for evaluating or monitoring the pollution of polycyclic aromatic hydrocarbons（PAHs） such as Phe.

关键词： phenanthrene hepatic enzyme biomarker hybrid tilapia ( Oreochromis niloticus ♀×O.aureus ♂ )

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Arabidopsis calcium-dependent protein kinase CPK28 is potentially involved in the response to osmotic stress

引用

Chinese Science Bulletin 2014年第11期59卷 1113-1122页

作者： Anli Gao qingyang wu Yu Zhang Yuchen Miao Chunpeng Song State Key Laboratory of Cotton Biology Institute of Plant Stress BiologyCollege of Life SciencesHenan University

As calcium sensors, plant calcium-dependent protein kinases(CDPKs) play important roles in plants' responses to various abiotic stresses. Here, we report the functional characterization of CPK28, a member of the CDPK family in Arabidopsis, in response to osmotic *** cpk28 mutant, a loss-of-function mutant, exhibited an NaCl- and mannitol-sensitive phenotype in green cotyledons, while CPK28-overexpressing plants displayed stronger tolerance to NaCl and mannitol stresses than wildtype plants. Reverse transcriptase-polymerase chain reaction and beta-glucuronidase staining assays showed that NaCl and mannitol stresses induced CPK28. CPK28-overexpressing lines accumulated significantly more proline relative to wild-type plants and mutant plants under NaCl and mannitol stresses. Transient expression of CPK28-GFP in mesophyll cell protoplasts, as well as stable transgenic lines expressing CPK28-GFP, showed that CPK28 was localized in the plasma membrane. Expression levels of known stress-responsive genes were not significantly altered in the null mutant and overexpression lines,suggesting that CPK28 possibly mediated the stress response via the regulation of target proteins rather than via regulation at the level of transcription. Meanwhile, CPK28could autophosphorylate. Taken together, these data demonstrated that CPK28, a potential positive regulator, is involved in the response to osmotic stress in Arabidopsis.

关键词：钙依赖蛋白激酶渗透胁迫拟南芥聚合酶链反应 CDPK 应激反应转录水平非生物胁迫

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Changes of visceral properties and digestive enzymes in the herbivorous marine teleost Siganus canaliculatus fed on different diets

引用

Acta Oceanologica Sinica 2018年第2期37卷 85-93页

作者： XIE Dizhi XU Shude wu qingyang CHEN Fang WANG Shuqi YOU Cuihong LI Yuanyou College of Marine Sciences South China Agricultural University Guangdong Provincial Key Laboratory of Marine Biotechnology Shantou University Guangdong VTR Bio-tech Co. Ltd

The rabbitfish Siganus canaliculatus is one of the few cultured herbivorous marine teleosts. To better understand the digestive physiology of this fish and provide data for designing formulated feed using macroalgae as an ingredient, the changes of visceral properties and digestive enzyme activities were investigated after the juveniles were fed on different types of food including raw fish（RF）, formulated diet（FD） or macroalgae Enteromorpha prolifra（EP） and Gracilaria lemaneiformis（GL） for eight weeks. The results showed that the hepatosomatic and viscerosomatic indices in the RF and FD groups, as well as the relative intestine length（RIL） in the EP and GL groups, were significantly higher than those in other groups. Additionally, differences in the histological structure of the liver and anterior intestine were also observed among different dietary groups. The hepatic nuclei were displaced to the periphery by lipid inclusions in fish fed RF. The highest levels of mucosal folds were found in the anterior intestines of fish fed macroalgae. Digestive enzyme activity profiles showed obvious fluctuations in the first three weeks, and then leveled off in the following weeks. The levels of protease, lipase and α-amylase in the alimentary tract showed changes related to the levels of dietary protein, lipid and carbohydrate, *** macroalgae significantly inhibited the activity of protease in the stomach, it increased RIL and the number of mucosal folds in the anterior intestine so as to compensate for the influences on protease activities in the stomach. This study suggests that the digestive tract of rabbitfish can well adapt to different diets, and needs about three weeks to physiologically acclimatize to the nutritional status, thus implying that rabbitfish are somewhat omnivorous.

关键词： digestive enzymes macroalgae Siganus canaliculatus visceral property

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structured-Light-Field 3D Imaging System With Coaxial Projection

引用

激光与光电子学进展 2023年第8期60卷 261-267页

作者： Zhang Zhijun wu qingyang Jiang Yifan Deng Yifeng College of Big Data and Internet Shenzhen Technology UniversityShenzhen 518118GuangdongChina

This paper presents a novel 3D measurement method for a light field camera(LFC)in which 3D information of object space is encoded by a microlens array(MLA).The light ray corresponding to each pixel of the LFC is *** the matching points from at least two subviews exhibit sub-pixel accuracy,the 3D coordinates can be calculated optimally by intersecting light rays of these points matched through phase ***,the proposed method obtains high-resolved results that exceed the subview resolution due to the virtual continuous phase search ***,we combine the LFC and coaxial projection to solve the 3D data loss caused by shadowing and occlusion *** results verify the feasibility of the proposed method,and the measurement error is about 30μm in a depth range of 60 mm.

关键词： light field 3D imaging microlens array structured light

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

僵尸企业如何影响企业污染排放:微观环境数据实证

引用

中国人口·资源与环境 2021年第11期31卷 34-47页

作者：吴清扬清华大学经济学研究所北京100084

妥善处置僵尸企业是实现高质量发展的关键。采用1999—2012年中国环境统计数据库与中国工业企业数据库的合并数据,在以构建熵权法计算的污染密度和以排污费计算的污染强度指标的基础上,从生态学和经济学两个维度,研究了僵尸企业对正常... 详细信息

妥善处置僵尸企业是实现高质量发展的关键。采用1999—2012年中国环境统计数据库与中国工业企业数据库的合并数据,在以构建熵权法计算的污染密度和以排污费计算的污染强度指标的基础上,从生态学和经济学两个维度,研究了僵尸企业对正常企业污染排放的影响。实证结果发现,僵尸企业比例越高,当地正常企业污染情况越严重,这一效应对轻工业及私有企业更加明显,上述结果在工具变量回归中均保持稳健,此外,该效应在政府干预能力更高的地区和创新能力较低的城市更为显著。最后,通过中介效应检验得出,政府工业污染治理投资的挤出和企业新增“三废”净化排放设施的减少可能是正常企业受到影响的重要传导渠道。因此,提出建议:政府应将处理僵尸企业作为推动绿色转型和可持续发展的抓手,不断疏通政策堵点,加快畅通市场循环,特别是从环境角度评估僵尸企业的危害,对于以往财务指标未达到清算标准但直接、间接排污严重的企业,也应当考虑关停处理。与此同时,还要兼顾补偿多方利益,解决“钱从哪儿来”的问题,回答“人到哪儿去”的问题,借助市场机制出清僵尸企业,让沉淀的资源得到充分释放,助推经济的可持续发展。

关键词：僵尸企业微观环境数据污染排放

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Changing Lane Probability Estimating Model Based on Neural Network

Changing Lane Probability Estimating Model Based on Neural N...

引用

第26届中国控制与决策会议

作者： Jianqun Wang Rui Chai qingyang wu School of Mechanical Engineering Beijing Institute of Technology

ISBN: (纸本)9781479937097

Changing lane is one of the methods to reach the destination faster and also could bring more highway traffic accidents. This study through the traffic feature recognition, cluster analysis, similarity measurements and estimation, analyzed the vehicle operation parameter before changing lane, proposed a changing lane probability estimating model which combines the SOM（Self-Organization Map） and BP（Back Propagation） artificial neural network and had passed the test of the Vissim micro traffic simulation data. This model contributes to the dynastic analysis and evaluation for establishing the traffic safe system.

关键词： traffic safety changing lane probability estimating model neural network

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

土地供给质量促进了产业结构变迁吗——基于微观土地交易数据的实证研究

引用

现代经济探讨 2021年第12期 12-22页

作者：吴清扬清华大学经济学研究所北京100084

利用2000-2019年中国微观土地出让数据,用香农-维纳指数衡量土地供给质量,实证检验了土地供给质量对产业结构变迁的影响。研究结果表明:土地供给质量显著推动了产业结构升级,降低了产业间离散程度,该影响在地区创新能力强的地区和土地... 详细信息

利用2000-2019年中国微观土地出让数据,用香农-维纳指数衡量土地供给质量,实证检验了土地供给质量对产业结构变迁的影响。研究结果表明:土地供给质量显著推动了产业结构升级,降低了产业间离散程度,该影响在地区创新能力强的地区和土地产权明晰的省份表现得更为明显。土地要素市场化改革相对滞后可能是近年来经济发展结构性减速的重要原因之一。因此,要培育更多种类的土地一级市场主体,实施差异化土地供地模式;同时规范土地产权流转制度,建立竞争性供地长效机制。

关键词：土地供给质量产业结构变迁微观土地交易数据土地市场化改革

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

双摄像机相位测量轮廓术系统标定与数据融合

引用

光学学报 2006年第4期26卷 551-556页

作者：李勇苏显渝吴庆阳四川大学电子信息学院光电科学技术系成都610065

在将两个摄像机对同一坐标系(全局坐标系)标定的基础上,提出了距离数据及纹理的融合方法。以调制度为模板确定摄像机视线重叠区和数据空洞,在全局坐标中摄像机视线重叠区内根据单位面积采样点数序号最接近原则选取一定尺寸的区域作为数... 详细信息

在将两个摄像机对同一坐标系(全局坐标系)标定的基础上,提出了距离数据及纹理的融合方法。以调制度为模板确定摄像机视线重叠区和数据空洞,在全局坐标中摄像机视线重叠区内根据单位面积采样点数序号最接近原则选取一定尺寸的区域作为数据拼接区。并且考虑在重叠区内一方数据有空洞时的补洞方法,将空洞边界相似放大后,新边界和原边界构成的重叠区域作为数据拼接区。在数据拼接区内将两边的数据以到拼接区中心线距离为权重进行加权平均,实现了数据平滑过渡。实验表明该方法是有效的,为数据融合提供了新途径。

关键词：信息光学三维面形测量相位测量轮廓术相位-高度映射摄像机标定纹理融合

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

一种新的基于球面模型的鱼眼镜头标定方法

引用

中国激光 2015年第5期42卷 226-233页

作者：吴泽俊吴庆阳张佰春深圳大学电子科学与技术学院深圳市微纳光子信息技术重点实验室广东深圳518060

提出了一种新的基于二维靶标的球面模型鱼眼镜头标定方法。根据球面成像模型中圆弧上的点与图像坐标系像点之间的约束关系,利用平面靶上的一根直线上的点,初步估计出摄像头的内部参数。利用平面靶上棋盘格角点在世界坐标系上的坐标点与... 详细信息

提出了一种新的基于二维靶标的球面模型鱼眼镜头标定方法。根据球面成像模型中圆弧上的点与图像坐标系像点之间的约束关系,利用平面靶上的一根直线上的点,初步估计出摄像头的内部参数。利用平面靶上棋盘格角点在世界坐标系上的坐标点与其在球面坐标系下坐标的映射关系,求出相应的外部参数的初始值。以这些角点在图像中的实际坐标与重投影后坐标之间的均方差为优化参数,进行非线性优化,求出内部参数,畸变系数和外部参数的精确解。通过实验验证,该方法能够快速的估计鱼眼镜头的内、外部参数的初始值,具有较高的精度,能够满足实际应用的需求。

关键词：测量摄像机标定鱼眼镜头非线性优化

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：