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221.
Computer-supported visualization of rescue operations 总被引:1,自引:0,他引:1
Effective emergency management and response require a thorough understanding of the processes involved in a rescue operation and their interaction. Appropriate methods and tools for computer visualization of rescue operations can greatly facilitate activities such as command and control, system analysis, training, evaluation, and transfer of lessons learned. To this end, we introduce a method for systematic analysis, modeling and visualization of a rescue scenario. Models of rescue scenarios, prepared in advance, serve as the basis for data collection during an operation. The data collected are visualized in a computer tool with several views that can be customized according to the needs of different users. We demonstrate the method by applying it to a rescue operation where a taskforce trains for emergency response to a chemical incident. 相似文献
222.
The development of ecological modelling on global level since the middle of the 19th century is first reviewed, including application of statistical analysis, introduction of logistic curve, earth surface modeling, systems ecology, computer-oriented mathematical models and spatially explicit models. Finally, we discuss problems existing in ecological modelling on global level. 相似文献
223.
北京地区2019年2~3月供暖结束前后两次污染过程特征分析 总被引:2,自引:2,他引:0
以2019年2~3月北京两次污染过程为例,针对气象要素及污染物浓度进行特征分析,利用后向轨迹及WRF-CAMx模式,分析供暖结束前后的污染物演变规律,并探讨气象条件、区域输送及二次转化等对污染过程的影响.结果表明,2月21~24日(过程1)和3月18~20日(过程2)平均ρ(PM2.5)差异不大,分别为100.1 μg·m-3和97.2 μg·m-3,但过程1平均峰值偏高、日变化明显、过程发展迅速和有两个峰值阶段,且为区域性污染,而过程2更倾向于北京局地污染.两次过程逐时ρ(SO2)均不超16 μg·m-3,供暖燃煤治理效果显著,但过程1的SO2存在夜间次峰值,体现供暖排放影响.过程1的ρ(CO)较高,尤其是2月21~22日前后ρ(CO)/ρ(SO2)升高,且区域中南部城市及北京南部背景站污染高于城区,表明过程1扩散条件不利,且第一个峰值主要受区域输送影响.过程2的ρ(PM2.5)/ρ(CO)偏高,表明二次生成PM2.5占比略大;ρ(NO2)/ρ(CO)、ρ(SO2)/ρ(CO)和ρ(SO42-)/ρ(PM2.5)偏大,SOR与过程1持平,表明过程1更有利于气体相态转化,过程2受工业燃煤影响更大.但将过程1分阶段分析显示,过程1第二阶段与过程2的PM2.5二次生成指征相似,均高于过程1第一阶段,即过程1第二个峰值与过程2主要与本地排放和化学转化相关.WRF-CMAx对污染物演变趋势有较好的再现能力.同化试验对PM2.5趋势模拟显著提升,提高了与观测的相关性,但模拟值偏低;对NO2的模拟2月偏低、3月偏高,对SO2模拟明显偏高有一定纠正;此外,过程2中北京污染物浓度对河北的敏感性相对过程1偏低,即过程1受区域输送影响更大.模式对污染暴发性增长的模拟亟待提升,污染物种类对减排的响应及大气氧化剂和气溶胶性质相关的反馈等可能是影响模拟效果的重要原因,需进一步研究. 相似文献
224.
225.
Briassoulis H 《Environmental management》2001,27(1):1-11
Integrated analysis of land-use change in support of informed policy-making for sustainable land use at various spatial levels
makes heavy requirements for quality data. This paper aims to structure the principal methodological and practical issues
of data needs for this task. The data needs for local level analyses of land-use change are given special attention. The paper
adopts an integrated economic–environmental modeling framework and suggests the main types of data needed. Four main data
dimensions are distinguished: system of spatial reference, system of temporal reference, definitions, and data collection
procedures (sources, collection instruments and techniques, recording and retrieval systems, data format, frequency of data
collection). To evaluate the suitability of current data sets as well as to guide the collection of new ones, a scheme based
on substantive and practical criteria is employed. The former include compatibility, consistency, and reliability of data,
while the latter include availability, ease and cost of data collection/retrieval, and transferability of data. The evaluation
indicates the broad gaps in current data sets along the four main data dimensions. Based on this evaluation, the paper suggests
framework guidelines to address the main data issues identified. RID=" ID=" <SUP>1</SUP>CLAUDE: Coordinating Land Use and
Land Cover Data and Analyses in Europe. European Commission Concerted Action project (DG-XII); DAPLARCH: Data Plan Development
for Land Use and Land Cover Change Research. Program sponsored by IGBP-IHDP (LUCC and DIS). Street, Durham, North Carolina
27707, USA 相似文献
226.
子密钥数据库安全加密算法研究 总被引:1,自引:0,他引:1
姚志强 《中国安全科学学报》2007,17(1):111-115
探讨数据库的加密特点及其加密方法,并详细介绍一种类似DES(数据加密标准)的分组加密算法———子密钥数据库加密算法;同时分析和讨论如何实现数据库加密、解密以及更新;以微软数据库SQLServer2000为例,介绍数据库加密算法的实现过程,该实例应用广泛,在信息管理系统安全、电子商务等领域有很大的借鉴作用。 相似文献
227.
汽车驾驶操作信息数据库与采集系统设计 总被引:3,自引:3,他引:3
为提高驾驶操作监控技术研究效率 ,对驾驶操作数据、影响因素、车辆状态运行数据等进行分析并在此基础上进行了驾驶操作信息数据库概念结构、逻辑结构以及物理结构的设计。同时为提高驾驶操作数据采集的真实性 ,设计由工业控制计算机、数据采集卡、视觉传感器、力传感器、光电编码器、节气门开度传感器、传感器电路等组成车载驾驶操作信息多传感器采集实验系统 ,并分析了驾驶操作信息管理软件模块构成。 相似文献
228.
Abraham H. Parola Daniel Kost Gila Katsir Edna Ben-Izhak Monselise Rivka Cohen-Luria 《The Environmentalist》2005,25(2-4):103-111
Summary In previous publications, we reported that sinusoidal varying magnetic fields (SVMF) modify the activity and dynamics of the
malignancy marker adenosine deaminase, and enhance the proliferation of chick embryo fibroblasts (CEF). While the SVMF examined
by us (50, 60 & 100 Hz / 0.06–0.7 mT) were all below kT, they may have the potential of altering chemical processes in which
excited radicals are involved.
We tested this hypothesis in two experimental systems: CEF in culture and Spirodela oligorrhiza (Lemnaceae) (a small aquatic plant, commonly known as Duckweed). CEF were exposed to SVMF of 100 Hz/0.7 mT for 24 h. The addition of
the exogenous radical scavengers catalase, superoxide dismutase or vitamin E to the cells during exposure significantly suppressed
enhancement of cell proliferation caused by the field (by 79, 67 and 82%, respectively, as evaluated by the MTT colorimetric
assay). 15N NMR analysis of Duckweed plants fed by 15N-labeled ammonium chloride and exposed to SVMF at 60 and 100 Hz/0.7 mT for 24 h, revealed augmented alanine production. Alanine
did not accumulate in the absence of SVMF. The addition of vitamin C, a radical scavenger, reduced alanine production by 82%.
Exposure to SVMF resulted in specific metabolic stress effects in Duckweed plants and enhanced proliferation of CEF. In both
cases, it is suggested that free radicals are involved. 相似文献
229.
INTRODUCTION: Statistical models, such as Poisson or negative binomial regression models, have been employed to analyze vehicle accident frequency for many years. However, these models have their own model assumptions and pre-defined underlying relationship between dependent and independent variables. If these assumptions are violated, the model could lead to erroneous estimation of accident likelihood. Classification and Regression Tree (CART), one of the most widely applied data mining techniques, has been commonly employed in business administration, industry, and engineering. CART does not require any pre-defined underlying relationship between target (dependent) variable and predictors (independent variables) and has been shown to be a powerful tool, particularly for dealing with prediction and classification problems. METHOD: This study collected the 2001-2002 accident data of National Freeway 1 in Taiwan. A CART model and a negative binomial regression model were developed to establish the empirical relationship between traffic accidents and highway geometric variables, traffic characteristics, and environmental factors. RESULTS: The CART findings indicated that the average daily traffic volume and precipitation variables were the key determinants for freeway accident frequencies. By comparing the prediction performance between the CART and the negative binomial regression models, this study demonstrates that CART is a good alternative method for analyzing freeway accident frequencies. IMPACT ON INDUSTRY: By comparing the prediction performance between the CART and the negative binomial regression models, this study demonstrates that CART is a good alternative method for analyzing freeway accident frequencies. 相似文献
230.
一种新的数据融合方法 总被引:9,自引:2,他引:7
提出了一种新的数据融合方法,可以综合利用来自多个传感器的数据,评估所检测目标的漏检概率,与国际上常用的方法相比,其评估结果具有更高的精度,而且便于工程应用 相似文献