省级国土资源管理信息化发展研究

本文在对当前国土资源信息化存在的问题分析的基础上,提出进行数据整合、可复用构件提取、业务整合、登录门户整合、建立标准、在对国土资源信息化现状调查和对未来信息化发展趋势分析的基础上制定中远期发展规划和相应的具体实施方案来解决这些问题。     

可用于带耗散力卫星轨道长间隔积分的数值积分方法

本文分析了对称方法不适合带耗散力的卫星轨道长间隔积分的缺陷和本质原因,并针对这个问题,采用文所介绍的方法,构造并推荐了一组积分公式。     

珠江三角洲区域一体化研究综合信息系统的设计与应用

在分析地理信息系统技术发展与应用现状的基础上,设计了珠江三角洲区域一体化研究综合信息系统的结构框架。根据珠江三角洲的实际情况,并在经济地理学,城市地理学,区域科学等理论的指导下,开发了针对该区域一体化研究的模型分析系统。基于元数据库的数据集成与模型管理技术,能对不同数据源,不同数据类型与时空特性的多元数据处理与分析。本综合信息系统在区域产业布局,资源窨组合,城市体系空间结构演化等方面得到应用,将为     

Fast integration of low orbiter's trajectory perturbed by the earth's non-sphericity

A fast algorithm is proposed to integrate the trajectory of a low obiter perturbed by the earth's non-sphericity. The algorithm uses a separation degree to define the low-degree and the high-degree acceleration components, the former computed rigorously, and the latter interpolated from gridded accelerations. An FFT method is used to grid the accelerations. An optimal grid type for the algorithm depends on the trajectory's permissible error, speed, and memory capacity. Using the non-spherical accelerations computed from EGM96 to harmonic degree 360, orbit integrations were performed for a low orbiter at an altitude of 170 km. For a separation degree of 50, the new algorithm, together with the predict-pseudo correct method, speeds up the integration by 145 times compared to the conventional algorithm while keeping the errors in position and velocity below 10⁻⁴ m and 10⁻⁷ m/s for a 3-day arc. Received: 28 July 1997 / Accepted: 1 April 1998     

航空重力数据向下延拓的倒锥法(上)——方法的提出和存在性

基于离散 Possion积分提出了一种灵活直接的向下延拓新方法 ,证明了方法的存在性 ,利用模拟数据进行的数值实验取得了很好的效果。     

Elasto‐plastic analysis of block structures through a homogenization method

The paper describes the development and numerical implementation of a constitutive relationship for modeling the elasto‐plastic behavior of block structures with periodic texture, regarded at a macroscopic scale as homogenized anisotropic media. The macroscopic model is shown to retain memory of the mechanical characteristics of the joints and of the shape of the blocks. The overall mechanical properties display anisotropy and singularities in the yield surface, arising from the discrete nature of the block structure and the geometrical arrangement of the units. The model is formulated in the framework of multi‐surface plasticity. It is implemented in an finite element (FE) code by means of two different algorithms: an implicit return mapping scheme and a minimization algorithm directly derived from the Haar–Karman principle. The model is validated against analytical and experimental results: the comparison between the homogenized continuum and the original block assembly shows a good agreement in terms of ultimate inelastic behavior, when the size of the block is small as compared with that of the whole assembly. Copyright © 2009 John Wiley & Sons, Ltd.     

A fuzzy dynamic flood routing model for natural channels

A fuzzy dynamic flood routing model (FDFRM) for natural channels is presented, wherein the flood wave can be approximated to a monoclinal wave. This study is based on modification of an earlier published work by the same authors, where the nature of the wave was of gravity type. Momentum equation of the dynamic wave model is replaced by a fuzzy rule based model, while retaining the continuity equation in its complete form. Hence, the FDFRM gets rid of the assumptions associated with the momentum equation. Also, it overcomes the necessity of calculating friction slope (S_f) in flood routing and hence the associated uncertainties are eliminated. The fuzzy rule based model is developed on an equation for wave velocity, which is obtained in terms of discontinuities in the gradient of flow parameters. The channel reach is divided into a number of approximately uniform sub‐reaches. Training set required for development of the fuzzy rule based model for each sub‐reach is obtained from discharge‐area relationship at its mean section. For highly heterogeneous sub‐reaches, optimized fuzzy rule based models are obtained by means of a neuro‐fuzzy algorithm. For demonstration, the FDFRM is applied to flood routing problems in a fictitious channel with single uniform reach, in a fictitious channel with two uniform sub‐reaches and also in a natural channel with a number of approximately uniform sub‐reaches. It is observed that in cases of the fictitious channels, the FDFRM outputs match well with those of an implicit numerical model (INM), which solves the dynamic wave equations using an implicit numerical scheme. For the natural channel, the FDFRM outputs are comparable to those of the HEC‐RAS model. Copyright © 2009 John Wiley & Sons, Ltd.     

Identifying parameters controlling soil delayed behaviour from laboratory and in situ pressuremeter testing

The aim of this paper is to present a methodology for identifying the soil parameters controlling the delayed behaviour from laboratory and in situ pressuremeter tests by using an elasto‐viscoplastic model (EVP‐MCC) based on Perzyna's overstress theory and on the elasto‐plastic Modified Cam Clay model. The influence of both the model parameters and the soil permeability was studied under the loading condition of pressuremeter tests by coupling the proposed model equations with Biot's consolidation theory. On the basis of the parametric study, a methodology for identifying model parameters and soil permeability by inverse analysis from three levels of constant strain rate pressuremeter tests was then proposed and applied on tests performed on natural Saint‐Herblain clay. The methodology was validated by comparing the optimized values of soil parameters and the values of the same parameters obtained from laboratory test results, and also by using the identified parameters to simulate other tests on the same samples. The analysis of the drainage condition and the strain rate effect during a pressuremeter test demonstrated the coupled influence of consolidation and viscous effects on the test results. The numerical results also showed that the inverse analysis procedure could successfully determine the parameters controlling the time‐dependent soil behaviour. Copyright © 2008 John Wiley & Sons, Ltd.     

基于整合理论的高校教师管理

整合理论实质就是对组织所拥有的资源进行优化配置,使其协调发展,产生最大效益.对于高校,教师是所拥有的不可缺少,最具有潜力的资源,这种资源所发挥的协同作用存在巨大的潜力.从整合理论的角度,分析了高校教师管理方面的整合问题,提出了高校教师管理过程中应该注意的问题.     

行政赔偿因果关系的认定规则初探

行政赔偿因果关系的认定,直接关系到国家赔偿法效能的发挥.现实中,行政赔偿之所以陷入困境,其中一个重要原因是行政赔偿因果关系的认定缺乏标准.应从行政管理的规律出发,把握行政法律关系的特征,着眼于行政法未来的发展趋势,从充分发挥行政赔偿的内在功能入手,兼顾国家现实的赔偿能力及当前的法制人文环境,从理论上建立可供司法实践操作的行政赔偿因果关系认定规则.