首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Argo盐度资料延时质量控制的改进方法   总被引:2,自引:1,他引:1       下载免费PDF全文
针对现有Argo盐度资料延时质量控制方法(OW方法)在时空尺度参数与最优压力层选取方面的不足,在气候态盐度剖面客观估计过程中引入梯度依赖空间尺度法,以及在最优压力层的选取中提出一个利用气候态盐度资料代替浮标原始盐度观测资料的优化方案,构建了一个改进的Argo盐度资料延时质量控制方法。采用理论和现场观测资料检验等手段,对梯度依赖空间尺度法在资料客观估计中的可行性,以及优化方案对选取最优压力层的合理性做了验证。结果表明,梯度依赖空间尺度法在温盐梯度较大海域,可以将15 MPa水深以上的盐度估计精度提高0.01以上,而利用气候态盐度客观估计结果选取最优压力层的优化方案,能够更合理地选取最优压力层。  相似文献   

2.
为了检验改进的Argo延时质量控制方法对盐度漂移误差的校正效果,分别利用现有质量控制方法和改进方法,对太平洋海域3个代表性Argo浮标盐度观测资料进行了延时质量控制,并利用船载温盐探仪资料或高质量浮标资料,对2种方法的质量控制结果进行了对比验证。结果表明,在温盐度变化较大的海域,改进方法不仅能够有效地检测和判断电导率传感器发生漂移的浮标起始观测剖面,而且可以有效地校正由电导率漂移所带来的盐度误差,且校正的精度高于质量控制方法。在温盐度分布比较均匀的海域,2种方法对浮标盐度漂移误差的校正结果几乎无差异。  相似文献   

3.
针对标准化海洋盐度场产品较为匮乏的事实,利用Argo温盐观测剖面与卫星遥感海表温度资料,采用时空权重插值和多变量DINEOF方法,对太平洋区域2000年1月至2008年12月的三维逐周盐度场进行重构。提出的重构方法有2个明显特色,一是采用时空权重插值与多变量DINEOF相结合的方法,弥补了时空权重插值结果中包含缺失数据的不足;二是引入卫星遥感海表温度,弥补了Argo可靠海表数据的缺乏。重构再分析产品与其他观测和数据产品的对比结果表明,重构产品不但能够抓住盐度分布的主要模态特征,而且可表现盐度不同时间尺度的变化特征,为海洋和气候研究提供了一种有用的标准化数据新产品。  相似文献   

4.
西北太平洋温盐分布的时空尺度分析   总被引:1,自引:1,他引:0       下载免费PDF全文
为了更清晰地了解西北太平洋的温盐分布特征,基于全球实时海洋观测计划(Argo)浮标观测剖面,利用自相关函数方法,对西北太平洋海域(选取范围为120°E~160°W,10~40°N)温盐分布的时空尺度进行了分析,并通过高斯函数拟合得到了温盐的时空去相关尺度。研究表明,自相关函数随季节和深度发生变化,各层的自相关函数值随着空间增大而降低。表层,夏季温度的空间去相关尺度比冬季大,但时间去相关尺度小;次表层,夏季温度的自相关函数随空间增大迅速递减,空间去相关尺度比冬季小;深层,夏季和冬季的温度时空尺度相近。盐度的季节性变化较温度要小,但盐度的空间变化尺度比温度要大,而时间变化尺度则比温度小。2种要素的信噪比均大于2,可以用来指导精细化观测布网的采样间隔。  相似文献   

5.
针对无约束优化问题,利用两项共轭梯度法(DL方法)去逼近改进的HS三项共轭梯度法,提出了改进的DL共轭梯度法即MDL共轭梯度法.该方法相对于DL方法具有一个更好的性质,即该共轭梯度法的搜索方向不依赖任何线搜索就可满足充分下降条件,理论上证明了该方法在Wolfe线搜索条件下对一般函数具有全局收敛性.  相似文献   

6.
利用最小二乘法对潮汐实测资料进行分析,如何选择分潮是提高分析预报精度的关键。本文利用在频率域对潮汐振动特性进行分析的方法,可以客观地了解潮汐过程中存在着哪些振动,由此只要用较少的分潮就能组成精度较高的分潮模式。并以对连云港潮汐的分析预报,作了实例验证。结果表明,本文的方法可以避免选择分潮时的盲目性和偶然性,从而使潮汐分析预报的精度得到提高。  相似文献   

7.
利用最小二乘法对潮汐实测资料进行分析,如何选择分潮是提高分析预报精度的关键。本文利用在频率域对潮汐振动特性进行分析的方法,可以客观地了解潮汐过程中存在着哪些振动,由此只要用较少的分潮就能组成精度较高的分潮模式。并以对连云港潮汐的分析预报,作了实例验证。结果表明,本文的方法可以避免选择分潮时的盲目性和偶然性,从而使潮汐分析预报的精度得到提高。  相似文献   

8.
在物料配比系统中提前量辨识精确与否直接影响物料配比系统的配料精度,因此,提高提前量辨识精度是改进物料配比系统配料精度的前提.在分析了利用渐消记忆法进行提前量辨识的基础上,提出了利用Grubbs准则法进行提前量辨识,然后对这2种方法进行理论分析和蒙特卡洛方法计算机仿真.分析结果表明,利用Grubbs准则法进行提前量辨识的均方差远小于渐消记忆法辨识的均方差,并且可以有效剔除偶然误差,进而实现精确称量及提高配料精度.  相似文献   

9.
针对流程工业中难以直接测量的变量研究了其软测量方法.采用局部强逼近性能的RBF神经网络对被测变量进行建模;提出用峰值密度函数法确定RBF网络的隐含层节点数;设计样本信息分析算法提取样本特征,结合精度要求,初始化节点的中心向量和接收域宽度,消除了利用随机数等方法初始化训练参数和网络参数所造成的不确定性问题,同时提高了网络的收敛速度和精度;整个过程分别采用改进的梯度法、带有遗忘因子的最小二乘法等算法进行设计.利用改进的RBF网络对原油的直馏宽窄馏分的临界温度变量进行软测量建模、仿真.实验结果表明,基于改进的RBF网络的建模方法,在精度和收敛速度方面均有显著提高.  相似文献   

10.
随着微波遥感技术的迅猛发展,利用SAR影像提取海洋溢油区域已成为监测海洋溢油的重要手段之一.首先介绍了利用SAR影像监测海洋溢油的基本原理并对主要监测方法进行适用性分析.在此基础上,利用SAR影像对珠江口担杆岛附近海面进行了海洋溢油的提取实验,并从提取精度与算法的消耗时间两个方面对各种监测方法对比分析.实验结果表明:人工神经网络法和最大类间方差法的提取结果较为接近,适用于大范围溢油监测.而马尔柯夫链法算法消耗时间长,但精度较高,更适用于实时监测溢油扩散这样的随机过程.  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

14.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

15.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

16.
17.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

18.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

19.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

20.
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号