Exploiting Illusory Grid Lines for Object-Location Memory Performance in Urban Topographic Maps

In order to be successful in spatial orientation tasks, people need to recall locations and configurations of spatial objects from their memory. This understanding of geographic space often arises from experience with cartographic media representing topographic and topological information by graphic symbols. Learning spatial information from graphic media is influenced by different perception-based grouping effects distorting the accuracy of spatial object-positions and their relations. Such geometric inaccuracies can be softened by adding a grid layer, which regionalizes the map and can be used as an additional orientation pattern. This grid layer usually consists of solid lines and overlays semantic information. The present paper reports the results of two empirical studies on object-location memory (OLM) performance. In these studies, the amount of visual detail of the grid layer was reduced. By positioning the grid layer below specific urban topographic objects (study 1), the grid pattern was graphically interrupted. These interrupted grid lines were completed by cognitive completion mechanisms (illusory grid lines) described in the Gestalt principles of closure and continuation. The second experiment examined the maximum grid line gap that is closed by cognitive line completion and keeps an advantage for OLM (study 2).     

地球剖分格网研究进展综述

通过梳理近十多年来地球剖分格网的相关研究文献,从剖分建模(四边形剖分、等积剖分和立体剖分)、编码计算(层次编码运算、填充曲线编码运算和整数坐标编码运算)、质量评价(评价准则、评价因子和层次传播趋势)及典型应用(政府机构应用、商业系统应用和行业领域应用)等4个方面,对该领域研究进展进行了系统的分类分析,较为详细地给出了不同格网模型的结构特点、适用模式及其存在的不足。最后总结出地球剖分格网在理论基础完备性、格网计算高效性及格网质量可靠性等方面研究的前沿问题。     

基于全球剖分网格的地理空间信息保障服务技术研究

随着空间和对地观测技术的飞速发展,建立一个适应全球的多源、多尺度、多时相跨平台统一数据组织的网格框架具有非常重要的意义。当前地理空间数据的生产、维护分散在不同单位,且采用的数据网格标准各异,造成了部门或系统之间、不同历史阶段之间标准不统一。本文针对高分专项地理空间信息保障库对数据资源全局展示、关联检索和模版应用等综合服务展示需求,基于GeoSOT网格与编码理论体系,提出了"地理空间信息全球统一网格化编码管理"的数据剖分组织解决思路,并进行了系统分析、研究与设计。通过试验证明,基于GeoSOT虚拟一张图的数据组织管理方法能够显著提高地理空间信息保障服务系统的整体应用效能。     

几种地球剖分网格分析与初探

针对全球遥感卫星影像数据缺少统一组织框架的问题,从遥感影像数据特点出发,分析归纳了遥感影像统一组织框架的设计原则和设计难点,并对当前已提出的用于遥感影像统一组织的几种剖分格网方案进行概述。通过分析与比较,认为GeoSOT比较适合作为遥感影像的统一组织框架。     

基于实体模型索引的海量激光点云分块存储研究与应用

三维激光扫描技术的日益进步推动了点云数据量级的不断攀升,给海量点云的高效管理及优化处理带来新的挑战。文中针对在大范围点云场景中快速调度局部详细点云的实际应用需求,借鉴空间格网结构的数据组织思路,优化并提出可变长度的海量点云分层分条带存储的工作机制,结合数据库管理,实现了基于实体模型索引的激光点云及三维模型的快速调度及联动显示。基于研发的点云专家科研系统实践,推动了海量点云数据集约化管理水平,具有一定的科研及实用价值。     

利用激光点云的规则面微小变形统计分析

针对现阶段变形监测主要通过对单点位置的变化来对整体变形进行监测,因而局部变形很难监测出来的问题,文章提出了利用地基三维激光扫描数据具有高精度、高空间分辨率、点云数据量大的特点,对微小变形进行统计分析以及监测的方法:利用U检验证明点云数据偶然误差的分布满足正态分布;通过格网化处理对偶然误差进行消弱;通过拼接参数误差反解模型的建立,对拼接参数误差值进行求解,进而消除拼接参数误差,实现对激光点云的规则面微小变形的统计分析。     

基于AutoCAD及ANSYS平台的地质网格模型 建模方法探讨

对成矿过程进行数值模拟实验是当前开展成矿作用研究的新兴手段之一,其前处理阶段即计算用地质网格模型的建立往往成为制约后续实验过程的一个瓶颈,原因在于：一、地质体的形态不规则,甚至是复杂的,对其进行三维建模难度较大,所成模型也趋于简化处理,从而影响计算结果的精确性;二、专业的数值计算软件其建模模块稍弱,不足以应对复杂地质体模拟,而专业的建模软件往往又不具备模拟成矿过程的数值计算功能。因此需取长补短,对不同软件加以综合运用,实现对地质体的计算用网格模型构建。     

Comparison and Modification: TVD Schemes for Scalar Transport on An Unstructured Grid

In most TVD schemes, the r-factors were proposed according to the cell-centered (CC) finite volume method (FVM) framework for the numerical approximation to the convective term. However, it is questionable whether those r-factors would be appropriate and effective for the vertex-centered (VC) FVM. In the paper, we collected five kinds of r-factor formulae and found out that only three of those, respectively by Bruner (1996), Darwish and Moukalled (2003) and Cassuli and Zanolli (2005) can be formally extended to a context of the VC FVM. Numerical tests indicate that the TVD schemes and r-factors, after being extended and introduced to a context of the VC FVM, maintained their similar characteristics as in a context of the CC FVM. However, when the gradient-based r-factors and the SUPERBEE scheme were applied simultaneously, non-physical oscillations near the sharp step would appear. In the transient case, the oscillations were weaker in a context of the VC FVM than those in a context of the CC FVM, while the effect was reversed in the steady case. To eliminate disadvantages in the gradient-based r-factor formula, a new modification method by limiting values on the virtual node, namely in the paper, was validated by the tests to effectively dissipate spurious oscillations.     

重复点要素快速检查与消除方法

提出了一种快速实现土地利用现状图中重复点要素检查与消除的方法。首先将点层划分成若干个覆盖整个区域的一定尺寸的规格格网,对每个规格格网内的点要素采用传统顺序去重的方式进行重点消除。最后在AutoCAD平台上,使用ObjectARX开发工具,实现相应功能算法模型的设计,并验证了这一方法的可行性及有效性。     

基于格网单元的土地利用总体规划生态环境影响评价

开展土地利用总体规划生态环境影响评价实证研究,能够为不同城市的土地利用总体规划修编和生态环境保护提供依据。本文从土地利用结构和布局的角度,以格网为评价单元,运用生态系统服务功能价值评估法,对土地利用总体规划的结构调整所带来的生态服务价值的变化做了空间上的定量预测;并运用生态环境敏感性评价和GIS叠置法从土地利用布局上评价建设用地布局的生态合理性。以鄂城区为例,划分了702个格网,规划实施后生态系统服务功能总价值减少了414.54万元;建设用地布局具有较好的生态适宜性,只有0.23%分布在高度敏感区内。因此,鄂城区土地利用总体规划从生态环境保护角度是可行的,但还应注重对森林和水域等重要生态用地的保护。