Parallel cartographic modeling: a methodology for parallelizing spatial data processing     

Eric Shook  Michael E. Hodgson  Shaowen Wang  Babak Behzad  Kiumars Soltani  April Hiscox 《International journal of geographical information science》2016,30(12):2355-2376

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A new model of edge-to-edge contact for three dimensional discontinuous deformation analysis     

M. Mousakhani  A. Jafari 《Geomechanics and Geoengineering》2016,11(2):135-148

A robust contact theory can be regarded as key to three dimensional discontinuous deformation analyses (3D-DDA). Not only must this theory provide an efficient algorithm to judge the type and location of contacts but also it must be able to present comprehensive formulations for every kind of contact (open, sliding and locked contact). There are six types of contact in three dimensional discontinuous deformation analyses (vertex-to-vertex, vertex-to-edge, vertex-to-face, edge-to-edge, edge-to-face and face-to-face) that can be converted to vertex-to-face and edge-to-edge contacts. This paper presents a new model of edge-to-edge contact to three dimensional discontinuous deformation analyses (3D-DDA). This new model considers both kinds of edge-to-edge contact (cross-over and parallel edge-to-edge contact) and presents a criterion for inter-penetration. Sub matrices of normal and shear spring and friction force are derived by geometrical analysis and penalty method. This new model is implemented in a 3D-DDA computer programme, and the example results demonstrate the validity of the model.  相似文献   

Three-dimensional publication mode of Journal of Palaeogeography(Chinese Edition)          下载免费PDF全文

Li Xin-Po  Zhang Xi-Juan  Zheng Xiu-Juan 《古地理学报》2021,22(6):1233-1234

The network technology has provided impetus and channels for the development of sci-tech periodicals and promoted the transformation of the publication mode of Journal of Palaeogeography(Chinese Edition). Through the independent website construction,providing readers with diversified access to articles,diversified communication methods,personalized accurate article push,joining the OSID open science program,etc.,a three-dimensional publication mode adapted to the development of periodicals has been gradually formed.  相似文献   

Investigation of highly efficient algorithms for solving linear equations in the discontinuous deformation analysis method          下载免费PDF全文

Xiaodong Fu  Qian Sheng  Yonghui Zhang  Jian Chen 《国际地质力学数值与分析法杂志》2016,40(4):469-486

Large‐scale engineering computing using the discontinuous deformation analysis (DDA) method is time‐consuming, which hinders the application of the DDA method. The simulation result of a typical numerical example indicates that the linear equation solver is a key factor that affects the efficiency of the DDA method. In this paper, highly efficient algorithms for solving linear equations are investigated, and two modifications of the DDA programme are presented. The first modification is a linear equation solver with high efficiency. The block Jacobi (BJ) iterative method and the block conjugate gradient with Jacobi pre‐processing (Jacobi‐PCG) iterative method are introduced, and the key operations are detailed, including the matrix‐vector product and the diagonal matrix inversion. Another modification consists of a parallel linear equation solver, which is separately constructed based on the multi‐thread and CPU‐GPU heterogeneous platforms with OpenMP and CUDA, respectively. The simulation results from several numerical examples using the modified DDA programme demonstrate that the Jacobi‐PCG is a better iterative method for large‐scale engineering computing and that adoptive parallel strategies can greatly enhance computational efficiency. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

An application of Karmarkar's interior-point linear programming algorithm for multi-reservoir operations optimization     

K. Ponnambalam  A. Vannelli  T. E. Unny 《Stochastic Environmental Research and Risk Assessment (SERRA)》1989,3(1):17-29

Optimization of multi-reservoir systems operations is typically a very large scale optimization problem. The following are the three types of optimization problems solved using linear programming (LP): (i) deterministic optimization for multiple periods involving fine stage intervals, for example, from an hour to a week (ii) implicit stochastic optimization using multiple years of inflow data, and (iii) explicit stochastic optimization using probability distributions of inflow data. Until recently, the revised simplex method has been the most efficient solution method available for solving large scale LP problems. In this paper, we show that an implementation of the Karmarkar's interior-point LP algorithm with a newly developed stopping criterion solves optimization problems of large multi-reservoir operations more efficiently than the simplex method. For example, using a Micro VAX II minicomputer, a 40 year, monthly stage, two-reservoir system optimization problem is solved 7.8 times faster than the advanced simplex code in MINOS 5.0. The advantage of this method is expected to be greater as the size of the problem grows from two reservoirs to multiples of reservoirs. This paper presents the details of the implementation and testing and in addition, some other features of the Karmarkar's algorithm which makes it a valuable optimization tool are illuminated.  相似文献   

非充分灌溉制度设计优化模型   总被引：3，自引：3，他引：3       下载免费PDF全文

张展羽  何俊生 《水科学进展》1993,4(3):207-214

研究了缺水地区冬小麦灌溉问题.分析了作物模型,作物水分影响函数,并以农作物产量最大为目标,提出了非充分灌溉制度优化设计二维动态规划模型和相应的动态规划逐次逼近(DPSA)求解方法.针对山东省临沂市小埠东灌区的实际情况进行研究,求得了冬小麦三个典型年不同供水水平的最优灌溉制度、排水过程及相应产量.实例表明,模型及方法是合理的.  相似文献   

水电站水库群模糊优化调度模型与目标协调－模糊规划法   总被引：5，自引：1，他引：5       下载免费PDF全文

谢新民 《水科学进展》1995,6(3):189-197

利用大系统和模糊数学规划理论与方法,分析和探讨了水电站水库群模糊优化调度问题,建立了水电站水库群模糊优化调度模型,提出一种目标协调-模糊规划(IB-FP)法.理论分析和实例计算表明,所建立的模糊优化调度模型和提出的IB-FP法是可行和有效的.  相似文献   

吉林省南部下元古界集安群地质特征与沉积期古环境分析   总被引：5，自引：0，他引：5  

王福润 《吉林地质》1991,10(2):31-41

根据集安群地质特征,岩石化学,稳定同位素特征分析认为:蚂蚁河组沉积期古环境为强氧化泻湖相;荒岔沟组沉积期为强还原的泻湖相、大东岔组沉积期为开阔正常浅海潮坪相。集安群从发生发展到结束古环境演化规律是:构造上,由优地槽向冒地槽演化,气候上由炎热向温湿演化;古地理环境从有障壁的局限海变为无障壁的开阔海;从咸化海向正常海,从泻湖相向潮坪相转化。  相似文献   

岩石化学成分统计分析中的定和变量问题及其解决途径   总被引：2，自引：0，他引：2  

周建文 《岩石学报》1991,7(1):36-43

用岩石化学成分数据之类的定和数组计算相关系数或用于多元统计分析时,由于恒定总数约束的影响,致使结果出现很大的畸变。本文通过定和数组及对应的开数组之间的关系确定了开数组的范围,进而导出“误差对应模型”决定了该开数组,使恒定总数约束影响得以消除,最后用云南金顶铅锌矿的岩石化学分析样作了上述处理,取得了良好的实际效果。  相似文献   

基于动恣规划的整体影像匹配   总被引：1，自引：0，他引：1  

仇彤 《测绘学报》1994,(4)

影像匹配是数字摄影测量工作的基础。考虑到多条核线上的匹配点，本文提出了一种基于动态规划的整体影像匹配方法，构造了一种新的立体匹配模型，并将该模型转化成为简单的一维动态规划模型，采用对角线的方法划分阶段，用视差较和相关系数来构造阶段的代价函数，从而得到了基于动态规划的整体最优匹配结果。  相似文献