神经网络和主元分析-神经网络软测量技术在污水处理系统中的应用

为了实现对污水处理系统参数与性能的有效预测和处理系统的在线实时控制,在介绍神经网络和主元分析神经网络软测量技术的基础上,分析了神经网络在国内外污水处理领域的研究现状和存在的问题,探讨了神经网络软测量技术在污水处理系统的发展方向.结果表明,基于神经网络的软测量技术能够很好地进行数据分析与模拟仿真,这种软测量技术在污水处理系统中的应用可以通过优化神经网络结构、结合其他数据处理方法、全面预测污水处理系统重要参数、收集与生物处理过程密切相关的参数以及加强对污水生物处理数学模型的研究等方式得到不断改进和完善.     

地震多参数储层及油气预测应用研究

分析论述了地震多参数,包括速度、振幅、频率和相位等的提取以及在储层油气综合判别预测中的方法技术,并通过实例验证了该方法技术在碎屑岩储层油气预测中的有效性。     

基于D—S证据理论的多参数反演的火成岩识别——以塔里木盆地哈拉哈塘地区为例

塔里木盆地哈拉哈塘地区具有良好油源地质条件,该地区二叠系火成岩普遍发育,复杂的岩性和剧烈的厚度变化影响下覆油气资源的勘探.为识别该地区英安岩和玄武岩这2种主要分布的火成岩,分析不同岩性的特征响应,选取有效岩性识别参数,进行多参数反演;利用基于D-S证据理论的信息融合技术对多参数反演结果进行融合,挖掘参数反演数据体的优势信息,得到岩性识别的概率体,有效避免传统波阻抗反演结果的局限性.该方法可预测主要火成岩类型在空间上的展布和厚度变化,提高岩性解释精度,在识别火成岩岩性方面取得较好效果.     

裂缝性油藏离散裂缝网络模型

与常规碎屑岩储层相比,裂缝性油藏储层非均质性强,表征单元体尺度大,难以用等效连续模型表征,而离散裂缝网络模型可以描述储层任意尺度上的非均质性.从裂缝性储层识别预测技术、建模方法、模型应用等方面对离散裂缝网络模型进行分析,指出其发展趋势依赖3方面技术:(1)在储层识别和预测技术方面,需建立裂缝产状、长度、开度等属性的识别...     

室内用户语义位置预测研究

位置预测技术可以提前预知用户下一时刻的位置,在基于位置的服务（Location-based Service,LBS）领域中发挥着极其重要的作用。现有的位置预测技术大多仅使用用户的地理轨迹,仅使用地理轨迹挖掘出来的用户移动模式易受地理特性的限制缺乏深层次的语义信息。本文基于某商场群体用户的室内轨迹数据和语义信息预测用户下一个时刻语义位置。语义位置预测包括停留区域识别、停留区域语义匹配、语义位置建模。在停留区域识别阶段,为减少室内停留时间不固定对停留区域识别的影响,本研究提出了一种新型的时空凝聚层次聚类算法（Spatial-Temporal Agglomerative Nesting, ST-AGNES),该算法具有思想简单、超参数少、自动生成聚类个数等优点。在语义匹配阶段,引入了吸引度规则,充分利用停留区域所有轨迹点与室内高密度的商铺名称信息做匹配。最后,采用长短型记忆神经网络模型（Long Short-Term Memory,LSTM）挖掘群体用户的语义位置模式并预测用户未来的语义位置,实验预测正确率达到61.3%。     

基于神经网络的混沌时间序列预测

为了提高了RBF神经网络对于混沌时间序列的预测性能,从相空间重构理论出发,建立RBF神经网络,并且改变RBF神经网络训练参数及训练样本数,以Logistic及Lorenz混沌时间序列进行预测仿真,取得了不错的预测效果。     

样本数量不平衡下的建筑群模式识别方法研究

通过综合空间关系、几何、语义等多种特征对建筑群模式进行智能识别,在地图多尺度表达和数字化制图等领域有着重要的意义。将图卷积神经网络用于建筑群模式智能识别能够克服传统方法依赖人工经验设置参数、制定的规则过于严格等缺点。但是该方法往往存在样本比例失衡的问题,容易导致样本数量较少的类别无法正确识别。本文首先以建筑物质心作为样本进行聚类获得建筑群组。其次,将同一群组内的建筑物质心作为样本进行Delaunay三角剖分来构建建筑群的图结构,其中图节点特征选取能够描述建筑群几何特征的面积、大小、方向等相关指标。再次,通过图结构过采样的方式对样本数量较少的建筑群图结构进行增强,然后将样本数量较少的建筑群图结构增强前后的数据分别输入图卷积神经网络模型进行训练,并结合ROC曲线等多个评价指标对模型的性能进行了评测。实验结果表明,对样本数量较少的建筑群图结构增强之后,模型对于样本数量较少的建筑群识别准确率有了明显的提高。     

基于混沌时间序列的黄土滑坡变形预测方法及应用

采用GNSS技术进行滑坡变形监测时,由于多路径等观测误差的存在,直接使用GNSS监测结果进行变形预测会影响预测结果的精度。为了探讨GNSS测量误差对变形预测结果的影响程度,考虑到滑坡系统的混沌特性,采用混沌理论对陕西泾阳地区庙店滑坡GNSS变形监测结果抑噪处理前后的时间序列进行了对比分析。首先,采用互信息量法确定监测序列的时间延迟、用改进的虚假邻近点法(Cao算法)确定嵌入维数,获取相空间重构参数;然后使用最大Lyapunov指数对两种变形监测序列进行混沌特性识别;最后,分别使用加权一阶局域预测方法、最大Lyapunov指数预测方法和BP神经网络预测方法对滑坡变形监测结果进行预测。结果表明:GNSS滑坡变形监测结果抑噪处理前后的时间序列满足混沌特性,说明滑坡系统具有混沌特性;在3种混沌时间序列预测方法中,BP神经网络预测方法的效果较好,且该方法预测结果的平均绝对误差(MAE)和平均相对误差(MRE)分别为0.4 mm和11.9%,经过S-变换抑噪处理后,预测结果的平均绝对误差和平均相对误差分别为0.1 mm和4.1%,预测效果有明显改善。     

混沌RBF神经网络的地磁变化场预测模型

提出一种融合混沌理论和RBF(radial basis function)神经网络的地磁变化单站预测模型。分析磁场数据的混沌特性,求取关键参数嵌入维数m和时间延迟τ,据此对初始数据进行相空间重构,并将经混沌理论优化的样本集作为神经网络的训练集和测试集进行仿真实验。结果表明,经混沌理论改进后的RBF神经网络模型可以较为准确地预测地球磁场的变化趋势,对我国地磁场的适用性较好,具有一定的泛化能力。     

通过改进自适应PSO优化BP网络预测大坝变形

提出自适应粒子群神经网络（ADPPSO-BP）算法,并加入自适应变异算子,提高粒子跳出局部搜索的能力,实现对坝体位移的精准预测。以丰满大坝为例进行验证,建立PSO-BP（粒子群神经网络）、LPSO-BP（线性粒子群神经网络）、改进ADPPSO-BP（改进自适应粒子群神经网络）3种模型,对大坝进行变形预测。结果表明,ADPPSO-BP预测误差最小。     

Preliminary study on plasma membrane fluidity of Psychrophilic Yeast Rhodotorula sp.NJ298 in low temperature

The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.     

Information for authors

正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprehensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose     

JOURNAL OF OCEAN UNIVERSITY OF CHINA

<正>Copyright Submfnion of a roanusatpt inks:that the work described has not been published before(exoept In the form of an abstrW or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere that its publication has been approved by ail     

Information for Authors

<正>The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the publication of the theoretical and applied research results on oceanography and marine fisheries.The fieldcovered include the physical,chemical,biological,geo-     

Hydraulics and Hydrology in Mountain Areas

<正>The 35th IAHR World Congress was held in Chengdu,China from September 8 to September 132013.The title of the conference was:"The Wise Finds Pleasure in Water:Meandering through Water Science and Engineering".During the congress,1239 papers were presented in 139sessions for oral presentations and 7 sessions for poster presentations.After the Congress,a Committee was appointed to select some of the best papers presented at the Congress for publication,after a     

Sea ice thickness measurement in spring season in Bothnian Bay using an electromagnetic induction instrument

As an important component of the cryosphere,sea ice is very sensitive to the climate change.The study of the sea ice physics needs accurate sea ice thickness.This paper presents an electromagnetic-induction(EM) technique which can be used to measure the sea ice thickness distribution efficiently,and the successful application in Bothnian Bay.Based on the electromagnetic field theory and the electrical properties of sea ice and seawater,EM technique can detect the distance between the instrument and the ice/water interface accurately,than the sea ice thickness is obtained.Contrastive analysis of the apparent conductivity data obtained by EM and the value of drill-hole at same positions allows a construction of a transformable formula of the apparent conductivity to sea ice thickness.The verification of the sea ice thickness calculated by this formula indicates that EM technique is able to get reliable sea ice thickness with average relative error of only 12%.The statistic of all ice thickness profiles shows that the level ice distribution in Bothnian Bay was 0.4-0.6 m.     

Thermohaline structure inhomogeneity associated with polynia at the northern margin of Emery Ice-shelf

Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.     

Foreword

正Rapid changes of Arctic sea ice cover have been in the focus of the international climate research community in recent years.Quite a few of nations have completed a large number of related surveys and research projects in the Arctic Ocean.Up to now,China has performed six research cruises to the Arctic Ocean resulting in a significant volume of research output.Improved knowledge on the atmospheree-sea ice-ocean interactions in the Arctic is a