GIS技术在我国交通规划中的应用研究

就国内已经建立的尚在规划建设阶段以及停留在研究层面的,关于GIS技术在交通规划中的具体应用问题做了分析和总结,初步对深圳市交通仿真试验室之交通地理信息系统进行了系统需求分析,并提出了系统建设的功能和目标要求。     

Fuzzy logic algorithm for runoff-induced sediment transport from bare soil surfaces

Utilizing the rainfall intensity, and slope data, a fuzzy logic algorithm was developed to estimate sediment loads from bare soil surfaces. Considering slope and rainfall as input variables, the variables were fuzzified into fuzzy subsets. The fuzzy subsets of the variables were considered to have triangular membership functions. The relations among rainfall intensity, slope, and sediment transport were represented by a set of fuzzy rules. The fuzzy rules relating input variables to the output variable of sediment discharge were laid out in the IF-THEN format. The commonly used weighted average method was employed for the defuzzification procedure.The sediment load predicted by the fuzzy model was in satisfactory agreement with the measured sediment load data. Predicting the mean sediment loads from experimental runs, the performance of the fuzzy model was compared with that of the artificial neural networks (ANNs) and the physics-based models. The results of showed revealed that the fuzzy model performed better under very high rainfall intensities over different slopes and over very steep slopes under different rainfall intensities. This is closely related to the selection of the shape and frequency of the fuzzy membership functions in the fuzzy model.     

模糊优选神经网络在边坡稳定性分析中的应用

本文应用模糊优选神经网络理论,建立了边坡稳定性评价模型,综合分析了影响边坡稳定性的各种因素,根据它们作用程度的不同,赋予不同的权值,通过对收集到的边坡稳定性实例进行学习,提出了与优属度有关的函数关系式。可以看出:该方法具有精度高、收敛速度快、权值调整模型好等优点。     

Open Stope Stability Using 3D Joint Networks

Summary The most popular exploitation method used in Canadian hard rock mines is open stope mining. Geomechanical design of open stopes relies on a range of analytical, numerical and empirical tools. This paper presents an engineering approach for the analysis and the design of reinforcement for open stopes in jointed rock. The proposed methodology, illustrated by three case studies, relies on developing 3D joint network models from field data. The 3D joint networks have been successfully linked to a 3D limit equilibrium software package. The models account for the finite length of joints as well as the influence of random joints. The integrated approach facilitates comparative analyses of different reinforcement strategies under different degrees of jointing in the hard rock environment. Received February 23, 2001; accepted October 11, 2002; Published online January 21, 2003 Acknowledgments The financial support of the National Science and Engineering Council of Canada and the Institut de Recherche en Santé et Sécurité au Travail of Quebec and Noranda Inc. is greatly appreciated. Authors' address: Prof. John Hadjigeorgiou, Université Laval, Department of Mining, Metallurgy and Materials Engineering, G1K 7P4 Quebec City, Quebec, Canada; e-mail: john.hadjigeorgiou@gmn.ulaval.ca     

Modeling Conditional Distributions of Facies from Seismic Using Neural Nets

We present a general, flexible, and fast neural network approach to the modeling of a conditional distribution of a discrete random variable, given a continuous or discrete random vector. Although many more applications of the neural net technique could be envisioned, the aim is to apply the developed methodology to the integration of seismic data into reservoir models. Many geostatistical methods for integrating seismic data rely on a screening assumption of further away seismic events by the colocated seismic datum. Such assumption makes the task of modeling cross-covariances and local conditional distributions much easier. In many cases, however, the seismic data exhibit distinct and locally varying spatial patterns of continuity related to geological events such as channels, shale bodies, or fractures. The previous screening assumption prevents recognizing and hence utilizing these patterns of seismic data. In this paper we propose to relate seismic data to facies or petrophysical properties through a colocated window of seismic information instead of the single colocated seismic datum. The variation of seismic data from one window to another is accounted for. Several examples demonstrate that using such a window improves the predictive power of seismic data.     

Scanline Method to Determine the Fractal Nature of 2-D Fracture Networks

A previous method proposed to measure the fractal dimension of pore spaces is adapted and modified for 2-D fracture networks. The method relies on scanning a 2-D fracture network through successive straight lines from top to bottom and measuring the distance between two fractures. The fractal dimension is then obtained using the log–log plot of the feature size and the number of features for this particular size at different magnifications. It is shown in this study that the method proposed to measure the fractal dimension of porous structures can be applicable to 2-D fracture networks with some modifications after testing it on synthetic and natural fracture patterns. The method is simplified to be useful for practical applications in the fractal analysis of fracture networks. The results reveal that, on the basis of the direction of scanning lines, different fractal behavior and dimensions can be obtained indicating that 2-D fracture networks possess multifractal character. This approach takes into account the effect of fracture orientation on the fractal behavior and anisotropic nature of fracture networks as well as the fracture density, length, and spatial distribution.     

基于道路的地球同步卫星定位松驰解法

针对文献中定位方法的弱点，提出了一种通过道路宽度进行强制约束的松驰解法。该方法不仅能提高高等级道路上用户的定位精度，而且在保证方差最小的情况下，使用户总被限制在道路上。     

The Application of BP Networks to Land Suitability Evaluation

The back propagation (BP) model of artificial neural networks (ANN) has many good qualities comparing with ordinary methods in land suitability evaluation.Through analyzing ordinary methods‘ limitations,some sticking points of BP model used in land evaluation,such as network structure,learning algorithm,etc.,are discussed in detail,The land evaluation of Qionghai city is used as a case study.Fuzzy comprehensive assessment method was also employed in this evaluation for validating and comparing.     

基于影像的道路标线自动识别方法

利用图像处理技术和模式识别技术。提出了一种基于影像的道路标线自动识别方法，实验结果表明，该算法速度快，准确率高，适应性强。     

生石灰粉在二灰碎石混合料路基基层中的合理使用

就合肥市马鞍山路南段路面基层(二灰碎石)的施工中,试验路段施工时使用生石灰粉的情况,谈谈该类混合料在材料特性、室内试验、施工工艺上的特殊性.