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911.
Matthew Gandy 《Landscape Research》2016,41(4):433-440
The presence of ‘unintentional landscapes’ invites reflection on the difficulties in defining marginal or interstitial spaces, or indeed the concept of landscape itself. In some cases, so-called wastelands or terrain vague have been appropriated as spaces of adventure, creativity or discovery. In other cases, these anomalous spaces have been the focus of anxiety or disdain, or simply erased on account of their putative ‘emptiness’ to make way for more lucrative forms of land use. In recent years, however, fragments of spontaneous nature have been incorporated into landscape design, or even mimicked through the adoption of a ‘wasteland aesthetic’. Marginal spaces appear to transcend existing Eurocentric circuits of landscape discourse by offering multiple meanings and manifestations. Indeed, the cultural and scientific interest in these spaces lies precisely in their complexity and uncertainty. 相似文献
912.
Zafar Masood Zheng Jiangbin Muhammad Irfan Idrees Ahmad 《Computer Animation and Virtual Worlds》2023,34(2):e2108
Virtual globes render planetary-scale terrain and have limited support for 3D applications development. Game engines provide development environment for interactive 3D applications development and have limited support for world-scale terrain rendering. The game engine based terrain rendering methods lacks hardware based tessellation for high-performance. This work presents a novel method for a high-performance large-scale terrain rendering for high-fidelity display systems using game engine. The proposed method performs patch-based hierarchical culling of a multi-resolution terrain model to reduce rendering load. A view-based algorithm simplifies the patches with error control on GPU. Simplified patches are efficiently submitted for drawing using indirect mesh instancing feature of game engine. The proposed method utilizes hardware tessellation feature for high-performance model tessellation and accurate earth's surface construction using displacement mapping. The proposed method is evaluated by rendering scenes for high-quality output on consumer-level hardware. Flights are performed with various settings and results are compared with clipmap-based and state-of-the-art hardware tessellation based adaptive methods. The proposed method achieved 750, 575, and 540 frames-per-second for HD, full-HD, and ultra-HD display resolutions. 相似文献
913.
An optimal path provides efficient operation of unmanned ground vehicles (UGVs) for many kinds of tasks such as transportation, exploration, surveillance, and search and rescue in unstructured areas that include various unexpected obstacles. Various onboard sensors such as LiDAR, radar, sonar, and cameras are used to detect obstacles around the UGVs. However, their range of view is often limited by movable obstacles or barriers, resulting in inefficient path generation. Here, we present the aerial online mapping system to generate an efficient path for a UGV on a two-dimensional map. The map is updated by projecting obstacles detected in the aerial images taken by an unmanned aerial vehicle through an object detector based on a conventional convolutional neural network. The proposed system is implemented in real-time by a skid steering ground vehicle and a quadcopter with relatively small, low-cost embedded systems. The frameworks and each module of the systems are given in detail to evaluate the performance. The system is also demonstrated in unstructured outdoor environments such as in a football field and a park with unreliable communication links. The results show that the aerial online mapping is effective in path generation for autonomous UGVs in real environments. 相似文献
914.
《International Journal of Hydrogen Energy》2020,45(15):8695-8702
Design of novel inexpensive non-precious metal electrocatalysts to replace Pt based electrocatalysts for wide pH range hydrogen evolution reaction (HER) still remains great challenges and opportunities, for globally sustainable supply of clean hydrogen. Ni doped tungsten carbide nanocubes supported on Ni foam (W1-xNixC NCs/NF) synthesized via a hydrothermal-carbonization methods is reported. W1-xNixC NCs/NF electrocatalysts exhibit excellent catalytic performance with overpotentials lower than 50 mV in both acidic, alkaline and neutral medium. Meanwhile, large electrochemical surface area and better conductivities of W1-xNixC NCs/NF electrocatalysts are deemed in favour of its efficient catalytic properties. Moreover, the electrocatalysts show superior stability in wide pH range. It is believed that the present work provides a novel strategy for designing low-cost and efficient pH universal non-precious metal electrocatalysts for HER. 相似文献
915.
《Electronics and Communications in Japan》2017,100(4):76-82
Analysis of lightning electromagnetic field using the finite‐difference time‐domain (FDTD) method has been studies in recent year. However, large‐scale analysis on real environment has not been considered, because the FDTD method requires huge computational cost on large‐scale analysis. We proposed a three‐dimensional moving window FDTD (MW‐FDTD) with parallel computation and applied to large‐scale analysis of lightning electromagnetic field with a real numerical terrain model. In this paper, we have studied about large‐scale analysis of lightning electromagnetic field with real urban models considering many buildings using our MW‐FDTD with parallel computation. We have shown effects of observed electromagnetic field on urban model. 相似文献
916.
基于非结构三角形网格的自适应有限元正演模拟,对带地形海洋可控源电磁法(MCSEM)二维Occam反演算法进行了研究。该算法正演采用基于非结构网格的自适应有限元法,能用较少的单元剖分精确地模拟复杂起伏地形和构造模型。反演运用基于高斯牛顿法改进的快速Occam算法,能快速地搜索拉格朗日乘子、减少模型的搜索量。对二维海洋油气藏模型进行了反演计算,结果表明,该算法能稳定收敛到真实模型附近,具有较高的计算精度和计算效率。通过对带地形模型的反演,讨论了起伏地形下海洋可控源电磁场二维反演效果,为准确解释MCSEM数据提供了参考。 相似文献
917.
本文综述了与地面车辆振动有关的路面不平度研究现状,指出了目前软路面不平度沿用硬路面不平度测量方法存在的问题,提出了软路面不平度的定义,并指出有必要研究各种条件下原始地面不平度、车辙不平度以及有效不平度三者之间的关系,为研究车辆振动和评价车辆振动性能提供科学的依据。 相似文献
918.
为了准确评估武器装备在战场电磁环境中的作战效能,从定量分析的角度,采用三维矢量抛物方程方法建立电磁环境仿真模型,通过Kriging算法对地形高程进行插值,在理想边界条件下,分析了远距离不同高度的电磁波衰减特性,并与二维抛物方程计算结果进行比较。结论表明,电磁环境仿真模型能够给出战场电磁环境的基本数据,计算精度较高。 相似文献
919.
三维地形虚拟场景的网络浏览是近几年分布式虚拟现实技术、地理信息库技术和数字地球技术等研究重点.论述了基于VRML的LOD技术与大场景分割调度技术的三维地形虚拟场景浏览系统的设计与实现方案,并针对10241024DEM数据开发了基于Web的三维地形浏览实验系统. 相似文献
920.
大规模三维地形的生成和漫游 总被引：1，自引：0，他引：1
基于分块分层的地形LOD模型算法,结合视点相关因素,大幅度简化了大规模地形复杂场景,实现了研究区域三维地形可视化的实时绘制.运用多线程处理机制,提高了地形漫游的效率与可视化效果.实验结果表明,文中算法具有处理数据量大、效率高、效果好等特点. 相似文献