Prediction of groundwater inrush into coal mines from aquifers underlying the coal seams in China: vulnerability index method and its construction   总被引：5，自引：0，他引：5  

Qiang Wu  Wanfang Zhou 《Environmental Geology》2008,56(2):245-254

Groundwater inrushes often occur in the coal mines of China. One of the water sources is the aquifers underlying the coal seams. Because such a water hazard is affected by many factors, data collected from various sources need to be evaluated to predict its occurrence. This paper introduces an innovative approach in which the water inrush risk is represented by the vulnerability index. This method combines the geographic information system and the artificial neural network. The artificial neural network is used to estimate the weight of each factor. Unlike the traditional prediction method in which two controlling factors are often evaluated without regard to their relative importance, this new approach incorporates multi-factors and describes the non-linear dynamical processes.  相似文献   

GIS与OA集成技术研究     

刘纪平  周娜  张福浩  王振峰 《测绘科学》2007,32(Z1):14-16

本文介绍了GIS与OA集成的背景,分析了四种GIS与OA松散式集成方法的优缺点。在此基础上,根据GIS与OA的无缝集成的需要,提出了GIS与OA集成一体化数据管理的方法,在保证数据安全管理与统一控制的条件下,研究了基于组件、基于中间件、基于Web Service、基于本体等多种GIS与OA的无缝集成技术。最后,简要介绍了GIS和OA集成技术的实践情况。  相似文献   

Integration of the scientific community as exemplified by the biotech sector: An analysis based on bibliometric indicators in the Danish–Swedish border region     

Teis Hansen  Ronnie F. Hansen 《GeoJournal》2006,67(3):241-252

This paper presents an account of the progress of the integration between the Danish and Swedish parts of the Öresund Region within the world of science, with emphasis on biotech. The paper is based on data from the database Science Citation Index Expanded. The amount of co-authorships produced by agents from each side of the region is analysed for a 12-year period (1994–2005) and used as an indicator to show how the integration is proceeding. Each of the co-authorships is examined to shed light on the nature of the interactions, thereby identifying the agents most involved in collaboration. Furthermore, the development in co-authorships within the region is compared to the development in co-authorships between the Öresund Region and four selected reference areas. Our findings indicate that there has been a substantial increase in both the number of co-authorships overall and within biotech solely. The rise in co-authorships between the two parts is proceeding at a faster pace than the rise in co-authorships between the Öresund Region and the reference areas. The overall results of this paper indicate a growing integration of the biotech sector in the Öresund Region.  相似文献   

Confidence regions for GPS baselines by Bayesian statistics     

B. Gundlich  K.-R. Koch 《Journal of Geodesy》2002,76(1):55-62

 The global positioning system (GPS) model is distinctive in the way that the unknown parameters are not only real-valued, the baseline coordinates, but also integers, the phase ambiguities. The GPS model therefore leads to a mixed integer–real-valued estimation problem. Common solutions are the float solution, which ignores the ambiguities being integers, or the fixed solution, where the ambiguities are estimated as integers and then are fixed. Confidence regions, so-called HPD (highest posterior density) regions, for the GPS baselines are derived by Bayesian statistics. They take care of the integer character of the phase ambiguities but still consider them as unknown parameters. Estimating these confidence regions leads to a numerical integration problem which is solved by Monte Carlo methods. This is computationally expensive so that approximations of the confidence regions are also developed. In an example it is shown that for a high confidence level the confidence region consists of more than one region. Received: 1 February 2001 / Accepted: 18 July 2001  相似文献   

农田生态系统氮,磷,钾平衡试验研究：以禹城站试验地为例   总被引：3，自引：0，他引：3  

胡朝炳  田振荣 《地理学报》1995,50(1):73-82

根据在禹城站养分平衡试验场２０个养分池内连续三年的试验，通过比较精确的田间试验和取样分析，探讨了估养了以禹城为代表的黄淮海平原类似地区农田生态系统氮、磷、钾营养元素的平衡。试验结果表明，在黄河冲积物母质上发育的土壤，钾的供应能力很强。在当前产量水平（１２０００ｋｇ／ｈａ／ａ）施用钾肥无效果，并出现“奢侈性消移”。氮、磷元素尤其是有效性氮和磷明显缺乏，是影响作物生产的主要因素。养分损失的主要途径是氨  相似文献   

从模型试验谈反射波法检测桩的完整性     

廖永初 《湖南地质》2001,20(3):207-210

论述一维杆件中反射波法的理论依据；激振、传感器本身性能和耦合方式是检测技术的关键。通过模型实验认识桩的缺陷与记录曲线的对应关系。  相似文献   

整体平差法在现代测量控制网建立中的技术优势     

吴向阳  胡伍生 《现代测绘》2003,26(2):5-7

整体平差法是一个严格而又有效的平差方法，其应用与现代计算机技术密切相关。本文介绍了整体平差法的基本原理，并以实测GPS控制网的布设为例，探讨了它在现代测量控制网建立中的具体应用及其技术优势。  相似文献   

Shoreline change at an infinite jetty for wave time series     

Todd L. Walton Jr.  Robert G. Dean 《Continental Shelf Research》2011,31(14):1474-1480

Future shoreline changes on a sandy beach with a structure such as a jetty or groin can be estimated when wave time series is known (i.e. sequence of wave height, period, and direction). This paper presents an extension of an existing solution (Pelnard-Considere, 1956) for the linearized partial differential equation for shoreline change at an infinite jetty where waves are time varying and when the angle of the shoreline is small with respect to the waves breaking at the shoreline. The novel solution provided in this paper allows the previous constant wave condition solution to be extended to the case where wave properties (i.e. wave direction, wave height, and wave period) are time varying. Example usage of the method presented shows that shorelines may be of different final plan form shape for time varying wave conditions even though the sediment transport along adjacent beaches is not spatially varying (i.e. spatially constant) from time step to time step. Although this difference in shape may have been known previously using numerical models, it could not be proved analytically. Reversals of wave height, period, and direction time series are shown to provide different final shoreline shapes even though the time series consists of the same waves although in different ordered time. The solution provided will allow one line numerical shoreline models to be tested using an analytic solution.  相似文献   

ＰＬＡ控制结构在新一代天气雷达产品集成中的应用     

徐芬  勾亚彬  焦圣明 《气象科学》2011,31(1):83-86

本文采用一个可编程逻辑阵列式(PLA)的多线程控制结构实现了并发处理多部新一代天气雷达站点基数据,串行生成多种雷达产品的策略;通过设置关键产品处理权传递和计数器的方式解决了某些产品并发处理时消耗较多计算机资源、易引发系统崩溃的问题;在此基础上构建了一个易于扩展雷达站点与雷达产品算法的新一代天气雷达综合处理平台。该平台集成了多种成熟可靠的天气雷达产品,可方便进行后续算法的扩展和新雷达站点的扩充,不仅可以作为区域性的天气雷达综合算法处理平台,也可为其他气象业务平台提供所需的雷达产品,推广前景良好。  相似文献   

GIS与SCADA集成技术的研究与应用     

王志岗  彭霈 《四川测绘》2011,34(1):14-17

针对GIS与电网SCADA一体化集成过程中存在的功能模块整合与数据共享问题,设计了系统一体化数据模型,建立SCADA主动实时数据库,并采用COM、数据库与中间件技术,基于ArcEngine与.Net平台开发并实现了集成系统的相关功能模块。实践表明,一体化数据库的建立不仅实现了地理数据与采集数据的无缝连接与共享,也保证了数据的一致性和系统的实时性。  相似文献