晚清民国时期的中国旧海关地图探析

晚清民国时期测绘出版的近千幅旧海关地图,是当时绘制出版的中国地图的主要部分,一般附于旧海关内部出版物之中,其部分地图的科学性、准确性总体上超过了大部分的传统地图,且基本上图文并茂。由于旧海关内部出版物深锁于国内外的图书馆和档案馆中,少有学者能窥海关出版物之真容,夹在书中的地图更不易被发现和利用。本文对近千幅旧海关地图的绘制时间、地图数量的空间差异、记载内容的分类,以及海关地图的来源、绘制特点,都做了比较全面的介绍,以便于学者开发利用旧海关地图。

浅析中国古代方志中的地图

本文在对方志资料的调研基础上 ,分析地图在古代方志中出现的状况、方志中地图绘制特点及其与普通地图的比较。

The Spatial Characteristics of a Line and Their Application to Line Simplification

This paper discusses the spatial knowledge related to a line ,and the characteristic points of lines is detected.According to the requirements of line generalization,new algorithms for identifying characteristic line points are presented.These characteristic points are used to improve the algorithms of line generalization.An algorithm for identifying bends is shown.In this paper,improved algorithms based on those by Douglas_Peucker,Visvalingam and Whyatt are shown.In this test,the progressive process of line generalization is emphasized.