Conference Reports

18th International Symposium of Cipa by D. M. Barber, p.505
48th Photogrammetric Week by A. T. Smart, p.506
5th Conference on Optical 3D Measurement Techniques by G. Hunter, p.509     

Book Review

Books reviewed:
S. Openshaw and R. J. Abrahart, Geocomputation
M. Craglia and H. Onsrud, Geographic Information Research: Transatlantic Perspectives
P. J. Halls, Spatial Information and the Environment
J. Sievers and T. Schneider, Second International Symposium on Geographical Names: Geonames 2000
J. C. Leachtenauer and R. G. Driggers, Surveillance and Reconnaissance Imaging Systems: Modelling and Performance Prediction
P. A. Longley, M. F. Goodchild, D. J. Maguire and D. W. Rhind, Geographic Information Systems and Science
Y. Q. Chen and Y. C. Lee, Geographical Data Acquisition
K. Borre, Plane Networks and their Applications.
A. Hirschfield and K. Bowers, Mapping and Analysing Crime Data: Lessons from Research and Practice
O. Koelbl, Proceedings of the Oeepe Workshop on Automation in Digital Photogrammetric Production
RICS Books, Vertical Aerial Photography and Derived Digital Imagery: Client Specification Guidelines
D. E. Reeve and J. R. Petch, Gis Organisations and People: A Socio-Technical Approach     

Developing a bivariate spatial association measure: An integration of Pearson's r and Moran's I

 This research is concerned with developing a bivariate spatial association measure or spatial correlation coefficient, which is intended to capture spatial association among observations in terms of their point-to-point relationships across two spatial patterns. The need for parameterization of the bivariate spatial dependence is precipitated by the realization that aspatial bivariate association measures, such as Pearson's correlation coefficient, do not recognize spatial distributional aspects of data sets. This study devises an L statistic by integrating Pearson's r as an aspatial bivariate association measure and Moran's I as a univariate spatial association measure. The concept of a spatial smoothing scalar (SSS) plays a pivotal role in this task. Received: 07 November 2000 / Accepted: 02 August 2001     

由直线和曲线混合组成的地形符号在DCS中的处理

在ＤＣＳ输出的地籍图上，有许多由直线段和曲线段组成的地物符号，用传统方法处理难以取得理想的绘图效果。本文在分析ＤＣＳ数据结构和属性码的基础上，提出了曲线部分按三次参数样条曲线逼近，讨论了直线段和曲线段的各种组合情况，并且通过正确地选择边值条件使二者之间．的连接比较符合实际。最后扼要分析了该类线段按虚线绘出时的处理方法。     

Histogram and scattergram smoothing using convex quadratic programming

An algorithm, based on convex quadratic programming, is proposed to smooth sample histograms. The resulting smoothed histogram remains close to the original histogram and honors target mean and variance. The algorithm is extended to smooth sample scattergrams. The resulting smoothed scattergram remains close to the original scattergram shape and the two previously smoothed marginal distributions and honors the target correlation coefficient.     

锤击法在桩基质量检测中的应用及实测曲线分析

锤击法在桩基质量检测中是一种行之有效的手段。本文结合工程实例对桩的常见缺陷及其反射波特征作了浅析,对锤击法实测曲线判读和解释进行了归纳总结。     

基于形态重构的图像去噪方法研究

应用数学形态学中的形态重构滤波,对噪声图像进行了处理,在去除噪声的同时,也保持了边缘及细节信息。     

Mathematical expressions used in amino acid racemisation geochronology—A review

A variety of mathematical expressions that describe changes over time (t) in the extent of amino acid racemisation (AAR, expressed as the ratio of d- to l-amino acid isomers or epimers) have been used in Quaternary geochronology. The integrated rate equation was first used to estimate fossil age from D/L but its geochronological utility is disadvantaged by uncertainties regarding the conformity of AAR in fossil protein to apparent reversible first-order kinetics for the entire reaction history. ‘Non-linear’ models have subsequently been used to relate D/L to t. The logarithmic equation successfully applied to Atlantic Coastal Plain research has not achieved widespread application, perhaps due to the regional calibration required if sensitivity to temperature is to be modelled, or the difficulties encountered when extending the model to include fossils with D/L<0.1. Success producing a linear correlation between D/L transformed with a power function and t has seen this approach emerge as one of the most commonly applied in AAR geochronology in recent years. Like parabola curve fitting, which has been applied to trends in D/L versus t in a variety of fossils and geographic settings, power transformations may not be suitable for geochronological modelling during the latter stages of amino acid diagenesis. Several studies have demonstrated the utility of simple and contingent linear equations for relating D/L to t. Future research should aim to reduce reliance on independent calibration and explore the geochronological benefits of AAR in pools other than the total hydrolysable amino acids.     

广义相遇法的拓展

当地表不规则时,用广义相遇法求取的折射层速度存在较大误差,针对于此,这里提出了一种基于广义相遇法的广义相遇静校圆滑法。其步骤如下:①利用广义相遇法求出针对不同XY值的广义相遇速度解析值和时间深度值;②根据时间深度值求出"静校正量",然后从旅行时间中减去静校正量;③绘出广义相遇速度解析曲线,求出速度。其中的步骤②,是把所求的静校正量从旅行时间中减去,就是把地表的影响消除,所以得到的值基本不受地表的影响。对某一模型用此方法,取得了比较理想的效果,尤其是对于地表比较小范围的突然变化,有很明显的效果。实践证明,该方法极大地提高了传统广义相遇法求取折射层波速的精度。     

Gibbs sampler by sampling-importance-resampling

Among the Markov chain Monte Carlo methods, the Gibbs sampler has the advantage that it samples from the conditional distributions for each unknown parameter, thus decomposing the sample space. In the case the conditional distributions are not tractable, the Gibbs sampler by means of sampling-importance-resampling is presented here. It uses the prior density function of a Bayesian analysis as the importance sampling distribution. This leads to a fast convergence of the Gibbs sampler as demonstrated by the smoothing with preserving the edges of 3D images of emission tomography.