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581.
介绍了火灾报警系统可靠性数字仿真原理和软件设计方法,并举出了运行实例,证明数字仿真技术在火灾报警系统可靠性分析方面具有良好的应用前景。 相似文献
582.
A model for predicting community mosaics and wildlife diversity resulting from fire disturbance to a forest ecosystem is presented. It applies an algorithm that delineates the size and shape of each patch from grid-based input data and calculates standard diversity measures for the entire mosaic of community patches and their included animal species. The user can print these diversity calculations, maps of the current community-type-age-class mosaic, and maps of habitat utilization by each animal species. Furthermore, the user can print estimates of changes in each resulting from natural disturbance. Although data and resolution level independent, the model is demonstrated and tested with data from the Lewis and Clark National Forest in Montana. 相似文献
583.
Close contact between arid, fire-vulnerable chaparral wildlands and urban development in southern California results in conflagrations that have burned 200,000 ha, destroyed 700 structures, and claimed 16 lives in a single year. In 1972, the U.S. Congress established FIRESCOPE to assist southern California fire and emergency agencies and to develop computer methods for the simulation of wildland fire behavior. 相似文献
584.
CFD方法对突发性化学事故中危险物质泄漏范围的确定 总被引:1,自引:0,他引:1
简要分析了目前国内主要用于预测易燃易爆(有毒)物质发生泄漏事故后浓度扩散范围的计算方法。并介绍了国际上比较成熟的计算流体力学相关软件的数学模型及特点和边界条件的设置。针对液氨发生泄漏后氨气在一定大气环境条件下扩散的过程和特征,建立了相应的数学模型并设置了边界条件,通过数值计算得到氨气在水平方向风速环境下在三维空间内浓度分布规律。通过分析氨气扩散后爆炸浓度下限范围,探讨了如何设置警戒区的方法。最后分析了将计算流体力学方法应用于确定易燃易爆(有毒)物质泄漏后浓度范围的前景与不足。 相似文献
585.
586.
Philip D. Gardner Hanna J. Cortner Keith F. Widaman Kathryn J. Stenberg 《Environmental management》1985,9(4):303-311
The formulation and implementation of new fire policies in the national forests depend upon public acceptance. A national survey of organized groups of forest users indicates that, contrary to the concern of many forest managers, considerable support exists for flexible fire suppression policies. Forest users are also willing to accept the risk associated with the manager's use of prescribed fire. However, important intergroup differences do exist. Such variation is discussed in relation to a number of socioeconomic variables, general fire knowledge, specific knowledge about the effects of low-intensity fires, and risk preference levels. 相似文献
587.
This paper describes the development and implementation ofPREPLAN, A Pristine Environment Planning Language and Simulator, for two conservation areas in Australia, Kosciusko National Park (New South Wales) and Tutanning Nature Reserve (Western Australia).PREPLAN was derived from the North American gradient modeling systems and theForest Planning Language and Simulator (FORPLAN), but includes unique characteristics not previously available.PREPLAN includes an integrated resource management data base, modules for predicting site-specific vegetation, fuels, animals, fire behavior, and fire effects, and an English language instruction set.PREPLAN was developed specifically to provide available information and understanding of ecosystems to managers in a readily accessible and usable form, and to provide the motivation to conduct additional required research projects. An evaluation of the system's advantages and limitations is presented, and the way the utilization of such systems is improving natural area decision making throughout Australia is discussed. 相似文献
588.
589.
Sustainability in electrical and electronic equipment closed-loop supply chains: A System Dynamics approach 总被引:3,自引:0,他引:3
In this paper we examine the impact of ecological motivation and technological innovations on the long-term behavior of a closed-loop supply chain with recycling activities. Ecological motivation manifests through legislation and green image factor, whereas technological innovations manifest through design for environment. We adopt System Dynamics methodology applied to many environmental systems seeking long-term gains. The developed model is implemented to a real-world supply chain of electrical equipment in Greece. Numerical analysis illustrates the factors concerned, like the delay of the legislation enforcement, to achieve a sustainable future through non-renewable resources and landfill preservation. 相似文献
590.
本文运用系统动力学原理,构建了徐州市水资源承载力系统SD模型。并利用该模型,研究徐州市水资源承载力在不同发展方案下的变化趋势。最终得出开源、节流、治污并举的综合方案是徐州市水资源可持续发展利用的最优方案,同时指出开源措施对徐州市水资源承载力提高效果最为明显。并有针对性的提出提高徐州水资源承载力的建议与措施。 相似文献