基于群体搜索的串行蒙特卡罗反演方法的并行算法(英文)     

魏超  李小凡  郑晓东 《应用地球物理》2010,7(2):127-134

随着并行计算技术的发展,非线性反演计算效率在不断提高,但对于基于单点搜索的非线性反演方法,其并行算法的实现则是一个难题。本文将群体搜索的思想引入到基于单点搜索的非线性反演方法,构建了并行算法,以量子蒙特卡罗方法为例进行了二维地震波速度反演及实际资料波阻抗反演,并测试了使用不同节点数进行计算的效率。计算结果表明:该并行算法在理论和实际资料反演中是可行的和有效的,具有很好的通用性;算法计算效率随着使用节点数的增加而提高,但算法计算效率的提高幅度随着使用节点数的增加逐渐减小。  相似文献   

基于改进果蝇算法的非线性模型参数估计方法     

范千 《大地测量与地球动力学》2016,36(12):1092-1096

在对基本果蝇优化算法的寻优流程进行深入分析的基础上,提出一种单方向搜索处理的改进果蝇优化算法（IFOA）。该方法可以对极值点为非零非负的非线性函数进行优化处理,将其应用于非线性模型参数估计。实例表明,IFOA方法在参数估计精度上优于线性近似法与非线性迭代方法;与以遗传算法为代表的智能搜索方法相比,其估计精度相当,并具有参数设置少、寻优过程简单、易于程序实现等优点。  相似文献   

基于互联网搜索数据的甘肃省旅游客源地时空分析     

马威  张耀南  敏玉芳  陈玥 《中国沙漠》2016,36(3):857-864

传统的统计手段可以获得旅游城市或景点的游客量,而无法获得旅游客源地游客量,本文首先把互联网搜索数据与现实游客行为之间进行关联和映射,然后将搜索量最高关键词通过自由组合和非线性多项式拟合,发现3个词组合时与现实游客行为之间R²高达0.999,最后反演出2011-2014年中国(港澳台除外)各省、直辖市和自治区至甘肃省旅游的人数,进行甘肃省旅游客源地时空数据可视化、时空数据异常探测、时空过程分析等,帮助旅游部门了解游客的来源及去处、游客的出行规律和爱好偏向,做出有针对性的决策。  相似文献   

碧口古陆周边锰矿找矿分析     

赵绳武  王猛 《西北地质》2009,42(4):46-52

前震旦系碧口群,属四川古陆核西北缘,中新元古代发育的岛弧型建造,经晋宁运动碰撞拼贴,组成扬子地台的一部分,本身固结成为古陆。在其周边及东部成带分布了含锰岩系。目前各含锰矿带上的锰矿床,具体层位归属有蓟县纪、震旦纪、寒武纪等之不同认识。经分析研究认为,含锰岩系均属前震旦纪摩大岭复背斜褶皱带（即碧口古陆）之上的盖层型震旦寒武纪沉积,大致应为同一时代,即晚震旦世。由于各带所处地质构造背景、沉积环境的不同,锰矿特征明显有异,南含锰矿带临接扬子地台,为弱还原地质环境相对稳定,以优质锰矿类型为主;北含锰矿带紧邻秦岭地槽,凹陷较深为还原环境,以高磷锰矿为主。在该带含锰岩系的构造岩性有利部位,易形成风化淋积型锰矿床。故在寻找锰矿过程中,应区别对待,注意优质锰矿的辨认,并对本区锰矿找矿标志及找矿方向提出建议。  相似文献   

A new discovery of transition rules for cellular automata by using cuckoo search algorithm     

Min Cao  Quanfei Shen  Yanxia Wang 《International journal of geographical information science》2013,27(5):806-824

This paper presents an intelligent approach to discover transition rules for cellular automata (CA) by using cuckoo search (CS) algorithm. CS algorithm is a novel evolutionary search algorithm for solving optimization problems by simulating breeding behavior of parasitic cuckoos. Each cuckoo searches the best upper and lower thresholds for each attribute as a zone. When the zones of all attributes are connected by the operator ‘And’ and linked with a cell status value, one CS-based transition rule is formed by using the explicit expression of ‘if-then’. With two distinct advantages of efficient random walk of Lévy flights and balanced mixing, CS algorithm performs well in both local search and guaranteed global convergence. Furthermore, the CA model with transition rules derived by CS algorithm (CS-CA) has been applied to simulate the urban expansion of Nanjing City, China. The simulation produces encouraging results, in terms of numeric accuracy and spatial distribution, in agreement with the actual patterns. Preliminary results suggest that this CS approach is well suitable for discovering reliable transition rules. The model validation and comparison show that the CS-CA model gets a higher accuracy than NULL, BCO-CA, PSO-CA, and ACO-CA models. Simulation results demonstrate the feasibility and practicability of applying CS algorithm to discover transition rules of CA for simulating geographical systems.  相似文献   

Life‐cycle cost assessment of RC and ECC frames using structural optimization     

Bora Gencturk 《地震工程与结构动力学》2013,42(1):61-79

In this study life‐cycle cost (LCC) assessment of structural frames is performed. Two different materials, reinforced concrete (RC) and reinforced engineered cementitious composites (ECC), with different response characteristics are used to model the frames. ECC is characterized by high tensile ductility and energy absorption and reduced crack widths when compared to conventional concrete. However, the material is more expensive than conventional concrete; therefore, in order to quantify the potential benefits that could be obtained by replacing concrete with ECC, the life‐cycle performance is evaluated in an optimization framework. Three different structural frames are considered: an RC only frame, an ECC only frame and a multi‐material (MX) frame in which ECC is selectively applied at the potential plastic hinge locations while the remainder of the frame is made of RC. The structural capacity and earthquake demand are evaluated using rigorous analysis methods to capitalize on different characteristics of concrete and ECC, and both aleatory and epistemic uncertainties are incorporated into the LCC formulation. It is found that both the initial and LCC of frames that use ECC are lower due to savings in material and labor cost of transverse reinforcement for the former and due to increased capacity and reduced demand for the latter. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

沈阳地震台大震速报震级差分析     

包秀敏  马莉  顾强强  梁一婧 《防灾减灾学报》2013,(3):64-67

利用沈阳台测算震级与国家台网速报标准震级进行比较,寻找存在震级差的原因,分析得出,台站测算震级存在误差的原因主要有震中距,方位角,地震震级等。  相似文献   

GPS姿态测量中模糊度搜索方法的确定与比较     

罗京辉  张文  姜德才  高峰  陈继伟  段彩梅 《测绘与空间地理信息》2013,(10):64-65,69

GPS载波相位观测值作为高精度观测量在姿态测量中得到广泛应用。姿态测量系统中,基线长度可以通过提前量测精确求得。作为约束条件,可以用于模糊度搜索,提高模糊度搜索效率和准确度。本文介绍了传统的LAMBDA方法,且在此基础上提出了附有基线长度约束的LAMBDA搜索方法,并比较了两者的搜索效率。  相似文献   

Distributed geospatial information processing: sharing distributed geospatial resources to support Digital Earth     

《International Journal of Digital Earth》2013,6(3):259-278

Abstract

This paper introduces a new concept, distributed geospatial information processing (DGIP), which refers to the process of geospatial information residing on computers geographically dispersed and connected through computer networks, and the contribution of DGIP to Digital Earth (DE). The DGIP plays a critical role in integrating the widely distributed geospatial resources to support the DE envisioned to utilise a wide variety of information. This paper addresses this role from three different aspects: 1) sharing Earth data, information, and services through geospatial interoperability supported by standardisation of contents and interfaces; 2) sharing computing and software resources through a GeoCyberinfrastructure supported by DGIP middleware; and 3) sharing knowledge within and across domains through ontology and semantic searches. Observing the long-term process for the research and development of an operational DE, we discuss and expect some practical contributions of the DGIP to the DE.  相似文献   

基于单差搜索的格拉纳斯双差模糊度固定方法     

史小雨  程鹏飞  蔡艳辉  徐彦田 《测绘科学》2013,38(5):143-145

格拉纳斯(GLONASS)系统采用频分多址技术,差分技术处理双差载波相位观测值时为保持模糊度参数的整数特性,需要加入伪距计算单差模糊度进行辅助求解。为了降低伪距观测误差对双差模糊度快速固定的影响,本文给出了一种GLONASS双差模糊度解算方法:建立检验搜索出最佳的单差模糊度,再固定双差模糊度;并利用实测数据对该方法进行验证,结果证明可以有效地减少伪距误差对双差模糊度解算的影响。  相似文献