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61.
对1966年3月8日和3月22日台地震中的房屋破坏情况进行统计,计算了地震区主要房屋土坯墙房在Ⅳ~Ⅸ度中的毁坏率、严重破坏率和中等破坏率。通过X ̄2检验得出,Ⅵ度和Ⅸ度区房屋毁坏率、严重破坏率和中等破坏率的分布均服从正态分布  相似文献   
62.
Anomaly analysis is used for various geophysics applications such as determination of geophysical structure's location and border detections. Besides the classical geophysical techniques, artificial intelligence based image processing algorithms have been found attractive for geophysical anomaly analysis. Recently, cellular neural networks (CNN) have been applied to geophysical data and satisfactory results are reported. CNN provides fast and parallel computational capability for geophysical image processing applications due to its filtering structure. The behavior of CNN is defined by two template matrices that are adjusted by a properly supervised learning algorithm. After training stage for geophysical data, Bouguer anomaly maps can be processed and analyzed sequentially. In this paper, CNN learning and processing capability have been improved, combining Wavelet functions and backpropagation learning algorithms. The new architecture is denoted as Wavelet-Cellular Neural networks (Wave-CNN) and it is employed to analyze Bouguer anomaly maps which are important to extract useful information in geophysics. At first, Wave-CNN performance is tested on synthetic geophysical data, which are created by a computer environment. Then, Bouguer anomaly maps of the Dumluca iron ore field have been analyzed and results are reported in comparison to real drilling results.  相似文献   
63.
Life-cycle cost analysis of design practices for RC framed structures   总被引:1,自引:1,他引:1  
The objective of this study is to perform life-cycle cost analysis on three design practices namely weak ground storey, short and floating columns and their combinations. Life-cycle cost analysis is recognized as the only suitable tool for assessing the structural performance when the structure is expected to be functional for a long period of time. Life-cycle cost analysis is considered in this study assessing the behaviour of the three design practices against earthquake hazard. Although, a number of checks are performed in order to reduce the influence of these design practices on the seismic behaviour of reinforced concrete (RC) framed structures, it was found that the total life-cycle cost of partially infilled RC designs is significantly increased compared to that of the fully infilled one. Through the test example examined in the framework of this study general conclusions are obtained regarding the behaviour of the three design practices.  相似文献   
64.
刘家仁 《贵州地质》2002,19(1):52-59
为了简化地质构造力学分析,本文探讨了用内力线来描绘应力场的方法,仿照用磁力线描绘磁场的做法,约定以从外力作用点,支承点等处发出的一族主应力迹线为代表内力传递路径的“内力线”,根据弹性理论绘制了部分简单应力场的内力线图,阐述了以简单应力场内力线图为基础绘制复杂应力场内力线图并对之进行分析的方法,同时,文中还对这一方法在山字型构造体系和断裂等板内构造应力场分析,隐伏或未知构及地质的推测,地震预报等方面的应用做了尝试。  相似文献   
65.
The extraction of road networks from digital imagery is a fundamental image analysis operation. Common problems encountered in automated road extraction include high sensitivity to typical scene clutter in high-resolution imagery, and inefficiency to meaningfully exploit multispectral imagery (MSI). With a ground sample distance (GSD) of less than 2 m per pixel, roads can be broadly described as elongated regions. We propose an approach of elongated region-based analysis for 2D road extraction from high-resolution imagery, which is suitable for MSI, and is insensitive to conventional edge definition. A self-organising road map (SORM) algorithm is presented, inspired from a specialised variation of Kohonen's self-organising map (SOM) neural network algorithm. A spectrally classified high-resolution image is assumed to be the input for our analysis. Our approach proceeds by performing spatial cluster analysis as a mid-level processing technique. This allows us to improve tolerance to road clutter in high-resolution images, and to minimise the effect on road extraction of common classification errors. This approach is designed in consideration of the emerging trend towards high-resolution multispectral sensors. Preliminary results demonstrate robust road extraction ability due to the non-local approach, when presented with noisy input.  相似文献   
66.
本文系统阐述了国家自然地图集Internet版的设计和研制过程中的若干问题,包括系统的概念设计、系统开发中的WebGIS技术和策略,系统的主要功能和特色,以及系统维护和更新方案等。本系统从概念设计来看分为服务器端软件模块、浏览器端软件模块、国家自然地图集数据库支持等几个部分。系统开发中采取的WebGIS技术和策略有:兼顾服务器端和客户端的综合型WebGIS策略,基于Java Applet的 WebGIS浏览器开发技术,基于Map Object(MO)的WebGIS服务器开发技术等3个方面。在系统的主要功能特色方面,本文从以下5个方面进行了论述:科学有序的内容结构、清晰精练并带导航的界面、富有特色的信息查询功能、多重表达的地图可视化效果、一定的空间信息分析和制图功能。在系统维护和更新方案上,本文从网络技术、数据更新、功能开发3个方面介绍了计划,并对今后的发展趋势进行了展望。  相似文献   
67.
Harris  J. R.  Wilkinson  L.  Heather  K.  Fumerton  S.  Bernier  M. A.  Ayer  J.  Dahn  R. 《Natural Resources Research》2001,10(2):91-124
A Geographic Information System (GIS) is used to prepare and process digital geoscience data in a variety of ways for producing gold prospectivity maps of the Swayze greenstone belt, Ontario, Canada. Data used to produce these maps include geologic, geochemical, geophysical, and remotely sensed (Landsat). A number of modeling methods are used and are grouped into data-driven (weights of evidence, logistic regression) and knowledge-driven (index and Boolean overlay) methods. The weights of evidence (WofE) technique compares the spatial association of known gold prospects with various indicators (evidence maps) of gold mineralization, to derive a set of weights used to produce the final gold prospectivity map. Logistic regression derives statistical information from evidence maps over each known gold prospect and the coefficients derived from regression analysis are used to weight each evidence map. The gold prospectivity map produced from the index overlay process uses a weighting scheme that is derived from input by the geologist, whereas the Boolean method uses equally weighted binary evidence maps.The resultant gold prospectivity maps are somewhat different in this study as the data comprising the evidence maps were processed purposely differently for each modeling method. Several areas of high gold potential, some of which are coincident with known gold prospects, are evident on the gold prospectivity maps produced using all modeling methods. The majority of these occur in mafic rocks within high strain zones, which is typical of many Archean greenstone belts.  相似文献   
68.
Thematic maps can be analyzed by multiple regression for (1) forward prediction where a younger geological structural map is written as a least-squares function of older maps for information on historical perspectives or (2) by backward prediction where an older map is regressed stepwise on a series of younger ones to aid in prospecting. The technique was evaluated by a series of structure maps on different geological horizons from the U.S. Midcontinent (Kansas) where the forward prediction proved more effective than backward. In forward prediction, the first map entered into a multiple regression is invariably the immediately underlying one as expected. On the other hand, the first map in a backward prediction is not necessarily related to stratigraphy which limits the utility of the technique for prospecting.  相似文献   
69.
Different models were developed for evaluating the probabilistic three-dimensional (3-D) stability analysis of earth slopes and embankments under earthquake loading using both the safety factor and the displacement criteria of slope failure.The probabilistic models evaluate the probability of failure under seismic loading considering the different sources of uncertainties involved in the problem. The models also take into consideration the spatial variabilities and correlations of soil properties. The developed models are incorporated in a computer program PTDDSSA.These analysis/design procedures are incorporated within a code named SARETL developed in this study for stability analysis and remediation of earthquake triggered landslides. In addition to the dynamic inertia forces, the system takes into consideration local site effects.The code is capable of assessing the landslide hazard affecting major transportation routes in the event of earthquakes and preparing earthquake induced landslide hazard maps (i.e., maps showing expected displacements and probability of slope/embankments failure) for different earthquake magnitudes and environmental conditions. It can also beused for proposing a mitigation strategy against landslides.  相似文献   
70.
评估地震人员伤亡的软件系统   总被引:6,自引:1,他引:6       下载免费PDF全文
程家喻  杨哲 《地震地质》1996,18(4):462-470
设计了地震人员伤亡评估系统软件包,并利用该系统对北京地区假定地震发生后的人员伤亡进行了预测。为设计该系统,建立了北京地区的人口数据库、唐山和邢台地震人员伤亡数据库,对一天中人在不同时间段逗留在房屋内部的概率进行了讨论,从而建立了地震人员伤亡评估的数学模型。该系统作为地震灾害评估系统的子系统,主要用于地震人员伤亡的快速评估  相似文献   
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