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排序方式: 共有374条查询结果,搜索用时 15 毫秒
161.
利用摄像机构建数码城市模型   总被引:2,自引:0,他引:2  
介绍了将多张数码影像镶嵌拼接成“虚拟单像”的方法,解决了摄像机数码影像分辨率不高的问题,实现了城市建筑物、主要装饰物和地面景物的三维模型重建,对已有地形图而无合适航空影像的地区构成了数码城市模型,取得了有益的实验结果。  相似文献   
162.
简要介绍广西天气预报视频会商系统中心控制平台的基本操作方法,并针对在业务运行中出现的常见故障,进行原因分析,并找出解决方法。  相似文献   
163.
全天空成像观测是目前极光地面观测和反演磁层结构与动力学行为最有效的手段之一,本文介绍在参照WDC-C2极光数据中心ADPRS(AuroralDataProcessing&RetrievingSystem)系统功能的基础上,采用视频图像采集技术,首次在微机上开发成功的一个极光全天空视频图像分析系统.该系统在图像处理用户界面的构建上采用了视窗编程技术,在全天空图像到地磁坐标/地理坐标的投影变换中首次引入了强度修正因子,其功能可与ADPRS系统媲美.  相似文献   
164.
This paper describes the application of Canonical Correlation Analysis (CCA) to derive forcing–response relations between the wave climate and shoreline position on a macrotidal gravel barrier located in the southwest of the U.K., and to develop a tool to determine shoreline positions from wave records. The data sequences comprise wave climate recorded by a nearshore directional wave buoy and video-derived shorelines over a time span of one year and a half. The hydrodynamic conditions are used to determine the probability density function of wave heights and alongshore energy fluxes. These are then related to shoreline change through a CCA analysis. The CCA analysis identifies patterns of behaviour of the wave conditions and the shoreline position, and the relation between both patterns is found to provide useful information about the beach response to wave action. The analysis shows that the movement of sediment is greater at the southern end of the study area and that there is an immediate shoreline response to the wave action. In the case of coastal management it is more often the case that wave forecasts are available on a routine basis. The ability of the CCA to provide useful estimates of shorelines from wave conditions was tested by using measured waves to calculate the corresponding shoreline position from additional data at the end of the sequences. Shoreline positions determined with the CCA agreed well with the measured ones. Thus, the CCA is found to be a useful tool to determine unknown shoreline positions and support effective coastal management if good quality hydrodynamic and morphological data are available to input into the initial set-up of the technique.  相似文献   
165.
首先概述了"天津滨海新区风暴潮监测预报预警技术与示范"项目的背景,然后介绍使用GPRS-APN数据传输网络和3G网络通讯技术实现测站观测数据和视频图像传输、控制功能,最后介绍了项目数据通讯网络的运行情况。  相似文献   
166.
As catch and effort statistics including fishing time and location are essential for producing abundance indices for utilized fish stocks, fishing states are encouraged under the FAO Code of Conduct for Responsible Fisheries to collect and maintain such statistics. However, for coastal fisheries (including artisanal fisheries) that are mainly composed of small-sized vessels which are usually too numerous to monitor, fisheries statistics collection systems are often either lacking or of insufficient quality (e.g. incomplete or inaccurate). Vessel monitoring system (VMS) data are commonly used to construct or improve estimation of fishing effort and fishing location in large-scale fisheries. Most coastal fisheries lack VMS but their countries do have coastal surveillance radar systems (CSRS) for security and enforcement purposes. This study illustrates and recommends opportunistic use of CSRS data to provide similar scientific benefits to VMS data for coastal fisheries. CSRS in combination with market landings data can construct logbook-like catch and effort statistics. This study introduces a method and demonstrates its usefulness for scientific research and management purposes, including the potential to obtain a higher accuracy and precision, particularly for fishing location and catch amount. Limitations of the CSRS data and challenges to managers involved in its application are also discussed.  相似文献   
167.
基于定位视频的车辆导航原型系统设计与关键技术研究   总被引:1,自引:0,他引:1  
基于电子地图的导航系统相对抽象且缺乏沉浸感,不方便用户判别。为使导航效果更加直观和生动,该文提出基于定位视频的车辆导航思路,对车辆导航原型系统进行总体设计与实现,并探讨其关键技术。核心思想是建立道路定位视频(Geo-video)数据库,利用移动终端和固定目标的位置信息对定位视频数据库进行空间检索,将相应位置的视频图像传输给移动终端并实现路线和目标指引。试验证明该方法在技术上具有可行性。  相似文献   
168.
Participatory research is supposed to involve participants in a collective definition of goals, and the co-production and sharing of research outputs. However, when articulated through an extended period of time involving a range of local, national and international actors, the practicalities of participatory research means that certain groups and individuals become responsible for taking leading roles, with subsequent ethical dilemmas. In the ‘Community-owned solutions for future environmental challenges in the Guiana Shield, South America’ (COBRA) project, the participatory research process involves a group of five Indigenous researchers – “the local team” – in charge of carrying out the research on the ground e.g. defining procedures, carrying out community engagement and supporting the communities in analyzing and disseminating the material. This local team is, in turn, supported by researchers from a national NGO and foreign academics.Considerable responsibility has been given to the local team for achieving project outcomes, and freedom in defining project tasks and activities. This paper analyses the multiple ethical dilemmas arising out of this situation, particularly the role of the local team as intermediaries between the wider community and project partners. We highlight the existence of significant mismatches between research expectations, and the ethical processes in operation at community level which are usually established on long-term, tacit and reciprocal relationships. We discuss how local community researchers are challenged with balancing the tensions between these two ethical polarities, while at the same time producing participatory research outcomes that are acceptable by everyone involved.  相似文献   
169.
利用3台二维视频雨滴谱仪(2DVD)、广州S波段双偏振雷达以及C-FMCW雷达资料,分析广东地区2017年5月8日一次飑线过程不同降水部位的雨滴谱特征。根据雨强随时间变化,区分对流降水区,同时以对流降水区为分界线,将此次飑线过程划分为飑线前部、飑线中部和飑线后部。结果表明,飑线不同降水部位雨滴谱特征存在明显的差别。飑线前部,粒子谱分布变化剧烈,中小粒径的粒子居多,粒子数浓度较飑线中部偏低;飑线中部,粒子分布较分散,中等粒子比重较高,粒子数浓度最高,雨强的增加主要与雨滴数浓度有关;飑线后部,降水粒子分布较集中,且以高浓度中小粒子为主。另外,还研究了μ-Λ关系和Z-R关系。μ-Λ之间存在较好的二项式关系;不同降水部位Z-R关系差异较大,分别为Z=8.94R2.70、Z=526.98R1.22和Z=467.56R1.42。飑线不同部位雨滴谱演变特征存在一些明显差别,同时,同一部位不同空间位置也存在着一定的差异。  相似文献   
170.
中国地方政府财政赤字率的时空演变——地理监视的应用   总被引:1,自引:1,他引:1  
纪小美  王超  赵晓迪 《地理科学》2019,39(3):424-432
运用重心模型、时空跃迁和地理监视揭示了中国地市财政赤字率的时空演变规律与空间相互作用。赤字率重心西移,地域不均衡。赤字率分布具有路径依赖和空间溢出效应。经济越落后赤字风险越高,赤字冷点区集中于沿海且消退;热点区东扩且风险上升。赤字累积风险顺地势阶梯递减。 广大中东部地市为非预警区,继续积极财政政策,但支出需偏向社会福利,依靠内需拉动经济增长;预警区多为中西部工业城市,应增强内生动力以实现财政与经济长期协调发展;调控区集中于青藏高原及边缘,中央应加大扶持民生,减轻地方压力。  相似文献   
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