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61.
基于地基GPS层析大气水汽资源的方法研究   总被引:2,自引:1,他引:2  
大气水汽资源作为一种潜在的水资源,对实现淡水资源的可持续利用具有重要的战略意义。地基GPS层析大气水汽技术为研究大气水汽资源的三维分布提供了定量依据,对于合理开发利用大气水汽资源具有重要意义。论文介绍了地基GPS层析大气水汽技术的基本原理;层析网格的划分是地基GPS层析大气水汽技术的关键问题,文中对国内外地基GPS层析网格划分方法进行了论述,并总结了该技术普遍使用的3种模型,即对流层模型化算法、一般算法和Kalm an滤波法;最后提出地基GPS层析大气水汽技术中存在的问题,并对该技术未来发展方向给出了建议。  相似文献   
62.
刘晋  周勤  朱云  钟义龙  舒朝会 《四川环境》2007,26(6):119-122
对危险废物转移实时监控是实现其全过程管理的重要保证。针对国内外危险废物管理信息化发展和研究现状,指出城市危险废物转移安全监管存在的问题,提出有别于传统自建监控中心做法的基于商业平台监管危险废物转移的成本优化实施方案,实现对运输车辆的内外网两级安全监管。以广州市固废中心为案例,基于商业平台的危险废物监管系统在实现相同功能的前提下不仅大幅度降低系统建设和运营成本,还提高了事故应急响应速度,为我国各城市危险废物安全监管提供参考。  相似文献   
63.
Large marine protected areas (MPAs), each hundreds of thousands of square kilometers, have been set up by governments around the world over the last decade as part of efforts to reduce ocean biodiversity declines, yet their efficacy is hotly debated. The Chagos Archipelago MPA (640,000 km2) (Indian Ocean) lies at the heart of this debate. We conducted the first satellite tracking of a migratory species, the green turtle (Chelonia mydas), within the MPA and assessed the species’ use of protected versus unprotected areas. We developed an approach to estimate length of residence within the MPA that may have utility across migratory taxa including tuna and sharks. We recorded the longest ever published migration for an adult cheloniid turtle (3979 km). Seven of 8 tracked individuals migrated to distant foraging grounds, often ≥1000 km outside the MPA. One turtle traveled to foraging grounds within the MPA. Thus, networks of small MPAs, developed synergistically with larger MPAs, may increase the amount of time migrating species spend within protected areas. The MPA will protect turtles during the breeding season and will protect some turtles on their foraging grounds within the MPA and others during the first part of their long‐distance postbreeding oceanic migrations. International cooperation will be needed to develop the network of small MPAs needed to supplement the Chagos Archipelago MPA. Uso de los Patrones de Migración a Larga Distancia de una Especie en Peligro de Extinción para Informar a la Planeación de la Conservación del Área Marina Protegida más Grande  相似文献   
64.
Global positioning system (GPS) collars have revolutionized the collection of animal location data; however, it is well-recognized that considerable bias can be present in these data due to habitat or behavior-induced obstruction of satellite signals resulting in inaccurate or missing locations. To date, no explicit theoretical framework of GPS fix acquisition specific to animal telemetry has been presented, and studies make differing assumptions regarding factors influencing GPS fix acquisition and how these data should be analyzed. Inappropriate statistical models have been used, interaction effects have been misunderstood, and the implementation of bias mitigation techniques has been problematic. Herein we outline current conceptual and analytical problems in the GPS animal telemetry literature, and subsequently present a theoretical model-based framework for GPS fix acquisition that clarifies the single and interactive effects of habitat and behavioral obstruction, fix interval, and collar model on GPS collar performance. By recognizing that GPS fix acquisition is a Bernoulli process, it becomes apparent that all forms of obstruction inherently interact with each other, making generalizations across study areas, study species, and collar models problematic. Stationary collar tests to determine the probability of fix acquisition (PFA), location accuracy, and the response to sources of obstruction are thus of limited applicability to animal-deployed collars. Bias mitigation techniques that extrapolate PFA models across samples, especially those using stationary collar tests to correct animal-deployed collars, are theoretically unsound. It is also demonstrated that nonlinearities in the relationships between sources of obstruction and PFA complicate PFA modeling with limited data and that even slight model misspecification can lead to considerable errors in correction factors, especially when using inverse weighting to mitigate bias. By emphasizing the importance of GPS collar sensitivity and ephemeris retention, the theoretical framework predicts that newer, more sensitive GPS collars will be less severely biased by sources of obstruction than reported for the older, less sensitive collars that have been used in the majority of GPS performance studies to date and we expect this trend to continue. This heuristic modeling exercise should be of value to researchers planning and analyzing studies using GPS collars and it also establishes a starting point for future theoretical investigations into GPS collar performance and bias mitigation.  相似文献   
65.
Wildlife biologists are often interested in how an animal uses space and the habitat resources within that space. We propose a single model that estimates an animal’s home range and habitat selection parameters within that range while accounting for the inherent autocorrelation in frequently sampled telemetry data. The model is applied to brown bear telemetry data in southeast Alaska. This article is based on a portion of this author’s Ph.D. dissertation completed in 2003 at the University of Iowa.  相似文献   
66.
为推动化学品风险评估在我国的开展,对全球产品策略(GPS)进行研究。通过对GPS实施流程的分析,确定实施GPS的核心是开展化学品的风险评估(简称GPS风险评估)。将GPS风险评估与欧盟《化学品注册、评估、授权和限制》(REACH)法规要求的化学品安全评估(简称REACH CSA)和我国新化学物质登记要求的新物质风险评估进行对比,从评估物质的要求、效应评估的范围和方法、暴露评估的范围和方法以及风险表征的方法 4个方面分析其共同点和差异。确定GPS风险评估是简化版的REACH CSA,新物质风险评估相当于REACH CSA中的环境风险评估部分。最后认为,开展化学品全面风险评估是国际化学品管理发展的趋势。针对实际情况,提出宜采取简化评估和优先评估的方法,在我国逐步开展化学品全面风险评估。  相似文献   
67.
介绍了采油厂生产巡检在线信息管理系统的依托技术、管理网络、硬件构成、软件组成、试验情况和应用效果.该系统依托GPS和GIS等技术,采用了B/S结构、JAVA/JSP技术,能够准确及时显示巡检员的巡检路径,巡检结果从网上数据报表和电子地图及时看到,实现了实时监控,保障了油(水)井安全生产.  相似文献   
68.
基于全球定位系统(GPS)的电动车辆实时监控系统设计   总被引:1,自引:0,他引:1  
电动汽车以其良好的环保效应和灵活多样的能源利用形式,已成为国际社会普遍公认的汽车工业的重要发展方向之一,作为凸显可持续发展理念和国家科技产业实力的窗口,电动汽车的规模化应用将成为彰显2008北京“绿色奥运、科技奥运”主题的鲜明标志。为确保电动汽车奥运应用的安全性与可靠性,笔者提出了基于GPS的电动车辆实时监控系统的总体设计。该系统由车载信息采集终端(OBICT)、车辆运行监控(VOP)和无线通讯网络(WCN)3个子系统构成,并能对电动汽车运行中的电池及关键部件工作状态、车辆位置等数据进行实时采集与传输。在给出系统总体结构设计的基础上,对该车载信息采集终端、车辆运行监控子系统的数据流程进行分析,并提出了相应的软/硬件架构技术、设计方法以及实现的功能。  相似文献   
69.
Objective: Lacking information about actual driving speed on most roads in the Minneapolis–St. Paul region, we determine car speeds using observations from a Global Positioning System (GPS)-based travel survey. Speed of travel determines the likelihood and consequences of collisions. We identify the road segments where speeding occurs. This article then analyzes the relationship between link length, traveler characteristics, and speeding using GPS data collected from 152 individuals over a 7-day period as part of the Minneapolis–St. Paul Travel Behavior Inventory.

Methods: To investigate the relationship, we employed an algorithm and process to accurately match the GPS data with geographic information system (GIS) databases. Comparing actual travel speed from GPS data with posted speed limits, we measure where and when speeding occurs and by whom. We posit that link length and demographics shape the decision to speed.

Results: Speeding is widespread under both high speed limits (e.g., 60?mph [97?km/h]) and low speed limits (less than 25?mph [40?km/h]); in contrast, speeding is less common at 30–35?mph (48–56?km/h). The results suggest that driving patterns depend on the road type. We also find that when there are many intersections, the average link speed (and speeding) drops. Long links are conducive to speeding. Younger drivers and more educated drivers also speed more, and speeding occurs more often in the evening.

Conclusions: Road design and link length (or its converse, frequency of intersections) affect the likelihood of speeding. Use of increasingly available GPS data allows more systematic empirical analysis of designs and topologies that are conducive to road safety.  相似文献   
70.
2008年5月12日四川省汶川县发生了8.0级地震,本文作者参加了国家地震现场工作队第五灾害评估小组的灾害损失评估工作。本文基于此次地震灾害评估的经历,介绍了部分灾害评估装备的使用方法与技巧,总结了一些在地震灾害损失评估工作中节约资料处理时间的经验。  相似文献   
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