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为了考虑过程变量与质量变量的相关性,解决间歇过程的时序性和动态特性导致预测精度不高的问题,提出一种基于改进时空注意力-长短时记忆神经网络(improved spatial and temporal attention long short-term memory,ISTA-LSTM)的模型进行间歇过程质量预测.首先,对间歇过程的三维数据按变量方向展开成二维矩阵,对二维数据采用Min-max方法归一化;然后,使用偏最小二乘(PLS)方法对原始数据降维,提取数据的特征信息,基于时间注意力和空间注意力构建编码-解码器结构的双层LSTM网络,利用注意力机制自适应地学习神经网络参数,关注每一个过程变量对质量变量的重要性并分配相应的注意值,从而保留所有输入的必要信息,采用带交叉验证的网格搜索算法对预测模型进行超参数寻优,并建立预测模型;最后,在青霉素发酵仿真平台上进行实验验证,实验结果验证了所提模型对间歇过程质量预测的可行性和有效性. 相似文献
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Zhengmao Liu Xianguo Lu Sun Yonghe Chen Zhike Haitao Wu Yanbo Zhao 《Water Resources Management》2012,26(6):1455-1475
Naoli river basin(NRB), with an area of 24,863 km2, is the largest basin and also the largest marsh distribution area in Sanjiang Plain, Heilongjiang, China. The hydrological
evolution process of wetland in NRB has made a marked ecological responses for anthropic activities, also reflects the drying
trend of the Sanjiang Plain, Northeast China. Global climate warming also contributes to the hydrological evolution process.
The following key research results are obtained: (1) The monthly average water level of Naoli river at Caizuizi hydrological
station in different ages showed a marked decline tendency, the annual mean water level dropped from 96.63 m during 1960–1969
to 95.59 m during 2000–2005, the water level drawdown is 1.04 m; (2) The annual runoff flowing into wetlands in NRB decreased.
Duration of Naoli river and its tributaries being thoroughly frozen from riverbed to river-water-surface showed an prolonged
trend, and the water level drawdown in frozen seasons increased. The water storage capacities of wetlands in NRB declined.
(3) The interactions between ground water and surface water in wetland areas are close. The ground water level variation span
is bigger than that of surface water level in wetland areas of NRB. The drawdown of ground water level promotes the surface
water level to decline, correspondingly. In recent 20 years, the cultivated area extension of rice field in upstream NRB has
made an adverse influence on the hydrological processes of wetlands. (4) The wetland area decrease and farmland area increase
significantly contribute to the runoff depth decrease of wetlands in NRB. The runoff depth variability has been mostly posed
by anthropic activities. (5) Reservoirs, ditches and dykes in NRB have greatly changed the runoff generation processes. Thickness
of the seasonal frozen soil layer becoming thinner and the evaporation potential becoming bigger also contribute to the runoff
depth reduction and the water level drawdown of rivers. The present study results will provide a scientific basic for developing
an integrated watershed management program for NRB, especially, restoring the wetland hydrological processes, maintaining
or improving the wetland structure and enhancing the wetland service functions. 相似文献
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While dams cut off the migratory route of fish, and affect their growth and breeding, fishways are built to restore the connectivity of rivers and facilitate the life cycle of these migratory fish. This paper proposes a new kind of fishway called the "T shape fishway", and studies it by using both numerical simulations and physical experimental methods with the aim to design a fishway in China for migratory fish with swimming and jumping capability much poorer, such as schizothorax davidi and schizothorax prenanti, as compared with migratory fish in other places of the world, like trout and salmon. It is indicated that the range of velocity in each regular pool of the T shape fishway is from 0.42 m/s to 1.22 m/s when the flow discharge Q is 350 L/s, and there are no large vortex zones found there. This study shows that the T shape fishway can meet the requirements of these migratory fish quite well in terms of velocity and flow patterns in China. 相似文献
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山区高速公路路堑边坡在开挖过程中极可能发生坡体滑动、坍塌,甚至小规模崩塌现象,开发一种路堑边坡施工期多参数远程监测预警系统,保障工程施工期间施工方和当地群众的人身、财产安全显得极为重要。运用多种传感器技术实时地获取施工期间边坡倾斜度、位移和降雨量的变化情况,结合通用分组无线业务(GPRS)和手机短信服务(SMS)技术通过无线方式与上位机进行通信,建立被监测对象各类信息变化的数据库和网络发布平台,同时利用客户端管理软件对危险信息进行预警。通过在毕威高速公路的安装运行,系统成功地在施工期进行了监测预警,避免了不必要的人员伤亡和财产损失。 相似文献