勘探线剖面图从二维转化为三维算法

用勘探线剖面图结合钻井与其他资料进行地质模型三维重建是三维地质建模的重要方法。其中勘探线剖面图从二维坐标系向三维坐标系的转换是三维建模的一个重要环节。针对当前勘探线剖面坐标转换过程中勘探线上钻孔并不总是布置在一条直线上(弯折勘探线)的特点,该文提出了一种构建弯折三维剖面的方法。该方法首先由剖面线的起点、终点以及勘探线上钻孔孔口点作为转折点构建三维折勘探线剖面框架;然后将二维剖面图上分段转换剖面上要素点的二维坐标到三维空间,并对跨越剖面转折点的长边添加转折控制点;最后以青海某煤田勘探区的二维勘探线剖面图数据为例,利用该勘探线剖面坐标转换算法,实现了二维勘探线剖面图到三维勘探线剖面图的转化,结果表明三维剖面上保持了原二维剖面所表达的地质模型的几何形态。     

一种GIS共享图形软件符号的方法

针对GIS平台难以共享图形软件符号的问题,该文以AI符号为研究对象,提出了GIS共享AI图形系统点状符号方法。通过研究两类系统地图符号模型差异,分析AI图形符号与基于路径的点状符号结构,对比两类符号模型的几何结构与样式类型,验证了基于路径点状符号结构的通用性;通过设计AI图形符号数据向基于路径点状符号数据的映射方法,提出了GIS共享AI图形系统点状符号方法,实现了GIS平台对AI图形系统符号的共享。实验结果表明,利用基于路径的点状符号能够共享存在于AI图形软件的图形符号,实现GIS平台共享图形符号资源。     

数字城管基础数据库多尺度表达技术探讨

针对数字城管基础数据库多尺度表达的需求和缩放可视化中出现的问题,在研究二维电子地图的多尺度表达方法的基础上,提出并设计了基于分级显示的数字城管数据库多尺度表达技术。它将数据库中的各类数据进行有规则的分级,使其在不同的比例尺下显示出来。该文以宝鸡市为例进行了数字城管基础数据库多尺度表达的实验,结果证明基于分级显示的数字城管基础数据库多尺度表达技术是可行的。     

复杂区域内自动联结三角网方法研究

本文对传统的自动联结三角网方法进行了改进，建立了区域的内、外边界，在三角形网的扩展中增加了边界限制，将自动联结三角网方法推广到凹多边形区域和多联通区域，提高了联网速度。     

Design and Implementation of a Distributed GIS Portal for Oil Spill and Harmful Algal Bloom Monitoring in the Marine Environment

A web-based distributed system for monitoring and forecasting of the marine environment has been developed in line with INfrastructure for SPatial InfoRmation in Europe (INSPIRE) and Global Monitoring for Environment and Security (GMES) recommendations for a European Spatial Data Infrastructure (SDI). This system, called DISPRO, enables integration and distribution of multi-source data from satellites, aircraft, and in situ instruments, as well as results from numerical models. Geographic data and metadata are stored on a set of distributed computer nodes and retrieved and integrated by a web GIS client by means of Open Geospatial Consortium (OGC) Web Map Server (WMS) technologies. A profile of ISO 19115 was developed for metadata handling, using eXtensible Markup Language (XML) as a platform independent encoding mechanism. DISPRO has been demonstrated in six European coastal zone and ocean regions in the spring and summer of 2005. The overall positive experiences of both service providers and end users indicate that the system should be further developed into an operational GMES service.     

最新中国近海陆架底质类型图

本文系统地总结了编绘我国近海陆架沉积物(底质)类型分布图的历史和过程,阐述了近海海底沉积物的类型、分布及其形成规律,并提供了一幅最新的沉积类型图。     

Optimizing the reservoir operating rule curves by genetic algorithms

Genetic algorithms, founded upon the principle of evolution, are applicable to many optimization problems, especially popular for solving parameter optimization problems. Reservoir operating rule curves are the most common way for guiding and managing the reservoir operation. These rule curves traditionally are derived through intensive simulation techniques. The main aim of this study is to investigate the efficiency and effectiveness of two genetic algorithms (GAs), i.e., binary coded and real coded, to derive multipurpose reservoir operating rule curves. The curves are assumed to be piecewise linear functions where the coordinates of their inflection points are the unknowns and we want to optimize system performance. The applicability and effectiveness of the proposed methods are tested on the operation of the Shih‐Men reservoir in Taiwan. The current M‐5 operating curves of the Shih‐Men reservoir are also evaluated. The results show that the GAs provide an adequate, effective and robust way for searching the rule curves. Both sets of operating rule curves obtained from GAs have better performance, in terms of water release deficit and hydropower, than the current M‐5 operating rule curves, while the real‐coded GA is more efficient than the binary‐coded GA. Copyright © 2005 John Wiley & Sons, Ltd.     

Accessing Australian geodynamic information: The AGCRC website

The Australian Geodynamics Cooperative Research Centre (AGCRC) website <http://www.agcrc. csiro.au/> provides the main integrated presentation of the results of AGCRC research. It hosts a systematic presentation of project summaries, publication abstracts, regionally organised geodynamic syntheses and a GIS database containing a large number of broad‐scale earth science datasets from the Australian region, which are presented through an interactive map viewer. Effective interfaces are required to make the variety of content accessible to users. In particular, maintaining effective hyperlinking for a large and growing set of pages was a significant challenge. We found that by developing effective indexing tools we were able to apply a uniform technology to attack these problems. The index included both the full text of the pages from the website and also specific index terms of metadata. The metadata schema was designed to support both generalised discovery through a search interface and also to allow hyperlinks to be included automatically in pages by the server, so that the user could browse in a richly cross‐linked framework. It was necessary to manage textual and numeric data within the same framework because even the textual documents were generally tied to geospatial locations identified by their geographical coordinates. This required extensions to standard index and search tools, including the development of complete new indexing software. To assist the user in accessing the index, we provided a variety of user interfaces specialised for different themes in the website. For example, publication lists are generated in a conventional layout, and geospatial datasets are presented through an interactive map viewer and query system. The latter also demonstrated how visualisation tools for geospatial data can be provided in the web‐browser interface.     

Convection in a rotating,laterally heated annulus the wave number transitions

Abstract

The radial temperature differences at which the transitions from one wave number to the next occur have been measured with either increasing or decreasing positive radial temperature gradients, at five different rotation rates, with the fluid being always in thermal equilibrium and being in contact with an upper rigid lid. Hysteresis has been observed in all wave number transitions, and also in the transition to upper symmetry. There are, nevertheless, regions in the stability diagram where the wave number is unique. There is an excluded region where the wave number four cannot be obtained through quasi-steady procedure. There is a reversal of the sense of the hysteresis of the transitions. At low ΔT, a wave number transition with increasing radial temperature difference occurs at a higher ΔT, than the same transition with decreasing temperature difference. On the other hand, at large values of ΔT, a wave number transition with increasing radial temperature difference occurs at a lower ΔT, than the same transition with decreasing temperature difference. Wave number transitions with increasing ΔT, occur spontaneously out of amplitude oscillations. Wave number transitions with decreasing ΔT, occur via slow wave splitting in association with phase modulations of the waves. The uniqueness of the wave number in the unique areas of the stability diagram has been confirmed by sudden start experiments.     

Single‐and multi‐objective genetic algorithm optimization for identifying soil parameters

This paper discusses the quality of the procedure employed in identifying soil parameters by inverse analysis. This procedure includes a FEM‐simulation for which two constitutive models—a linear elastic perfectly plastic Mohr–Coulomb model and a strain‐hardening elasto‐plastic model—are successively considered. Two kinds of optimization algorithms have been used: a deterministic simplex method and a stochastic genetic method. The soil data come from the results of two pressuremeter tests, complemented by triaxial and resonant column testing. First, the inverse analysis has been performed separately on each pressuremeter test. The genetic method presents the advantage of providing a collection of satisfactory solutions, among which a geotechnical engineer has to choose the optimal one based on his scientific background and/or additional analyses based on further experimental test results. This advantage is enhanced when all the constitutive parameters sensitive to the considered problem have to be identified without restrictions in the search space. Second, the experimental values of the two pressuremeter tests have been processed simultaneously, so that the inverse analysis becomes a multi‐objective optimization problem. The genetic method allows the user to choose the most suitable parameter set according to the Pareto frontier and to guarantee the coherence between the tests. The sets of optimized parameters obtained from inverse analyses are then used to calculate the response of a spread footing, which is part of a predictive benchmark. The numerical results with respect to both the constitutive models and the inverse analysis procedure are discussed. Copyright © 2011 John Wiley & Sons, Ltd.