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91.
The problems faced by authorities in Saudi Arabia in managing the large numbers of pilgrims visiting Muna during a brief period each year has led to experiments with aerial photography and computer techniques. This paper describes briefly the new method initiated in 1981 emphasising the remarkably short time available for information assembly and interpretation and concludes with pointers towards the development of the techniques for Third World urbanisation studies.  相似文献   
92.
矿井火灾计算机模拟研究   总被引:2,自引:1,他引:2  
介绍了国内外矿井火灾计算机模拟技术发展的历史和现状。将现有的矿井火灾计算机摸拟方法分为稳态模拟、一维瞬态模拟和多维瞬态模拟,并对其特点进行了分析和评  相似文献   
93.
在使用数据库和计算机计算环境监测数据时,应该按照数值修约规则,编制和使用正确的计算处理程序。  相似文献   
94.
95.
Communities on oceanic islands are considered to be vulnerable to biological invasion. However, because the detailed structures of such communities have not yet been revealed, the relationship between their vulnerability and structure is not clear. Because such communities evolved without biological invasion, they are expected to have structures different from those of mainland communities, and this difference is expected to affect their vulnerability to invasion. I conducted computer simulations based on a food web model and investigated the difference in structure between mainland and insular model communities, the former of which evolved with frequent invasion and the latter without invasion. In addition, by conducting computer simulations of invasion of these model communities, I investigated the relationship between community structure and vulnerability to biological invasion. The insular model community evolved to have an unstable structure, in that a small number of plant species supported a large number of animal species, and each species in the community had a small biomass. When a plant species invaded and disturbed the base of the insular model community, many animal species relying on the plants easily became extinct. In addition, when a carnivorous species invaded, animal species with small biomass tended to become extinct. Community collapses caused by biological invasion occurred more frequently in the insular model community than in the mainland model community. These results indicated that those communities that evolved without invasion were vulnerable to invasion. The available data on real insular communities suggest that some have reached the endangered state predicted by this model.  相似文献   
96.
It is now widely recognised that good communication between multi-disciplinary stakeholders is central to effective flood risk management. Recent developments in Geographical Information Systems, increased availability of accurate digital terrain models from remotely sensed data sources and improved graphical computer interfaces have made the outputs from computer models of flood inundation easily accessible to the stakeholder community. As a consequence, predictions from such models are now being used routinely as a means of communication between engineers and other stakeholders in flood risk management. This paper provides a review of the modelling methods most appropriate for flood risk communication. These are one-dimensional models which are suitable for simulating flood risk at a catchment or sub-catchment scale and appropriate for communicating the impact of strategic flood management decisions and two-dimensional models which can be applied across a range of scales but, are now being regularly applied at the relatively small scale, less than 10 km2, where they have the potential to inform and communicate disaster management decisions. The role of such models in communicating between modellers and non-modellers by providing a means for immediate visualisation of “the future” is discussed and illustrated by application to two case studies.  相似文献   
97.
Surfactant enhanced aquifer remediation (SEAR) had previously been thought to require a capillary barrier below the contaminated zone to prevent the vertical migration of a microemulsion containing solubilized DNAPL. This paper shows the vertical migration of the dense microemulsion is described and predicted by the value of three dimensionless scaling groups. Embedded within these scaling groups are four design parameters. The value of these parameters can be manipulated in order to reduce the amount of vertical migration anticipated for a given remediation design. Plots have been constructed that illustrate the relationship between vertical migration and the value of the scaling groups; such plots can be used to predict vertical migration and to determine appropriate screen intervals of extraction wells to ensure full capture of the contaminants. This predictive capability has been verified in laboratory experiments. Predicted migration of the microemulsion agreed within about 2% of that observed. Development of the scaling groups is presented, remediation design implications are discussed, and laboratory verification is shown. Additional discussion of the laboratory work is given in a companion paper [Kostarelos, K., Pope, G.A., Rouse, B.A., Shook, G.M., 1998. A new concept: the use of neutrally-buoyant microemulsions for DNAPL remediation, J. Contam. Hydro., this edition].  相似文献   
98.
周边式二次沉淀池流态的计算模拟研究的数值方法   总被引:3,自引:0,他引:3       下载免费PDF全文
利用一种半解析半离散的数值方法来求解偏微分方程,从而确定二次沉淀池的流态。该方法具有精度高、速度快、占用计算机内存小的特点。所编制软件可在486微机上运行。计算结果与文献相比较,一致性很好,从而验证了本文方法的正确性。还给出了池型尺寸变化对池中心上部水流死区的影响,为具体设计者提供了参考依据。为进一步的优化设计创造了条件。   相似文献   
99.
This paper proposes that there is a need to quantify the value of void-to-solid ratio in residential facades. When quantified, void-to-solid ratio is expected to influence preference for these facades. To test this hypothesis, computer-simulated facades were created using a number of mesh editing and photo-editing software packages. The independent variable, void-to-solid ratio, was varied at three levels of windows' orientations and four levels of buildings' heights, resulting in 60 stimuli. A total of 174 participants were randomly sampled from Mutah University, Jordan, who input a total of 10,440 preference responses to the stimuli. The simulated facades were able to convey the values of void-to-solid ratios to participants. Responses revealed that there is an inverted U-shape relationship between preference for residential facades and their void-to-solid ratio, and that the most preferred range of void-to-solid ratios was (0.4–0.5).  相似文献   
100.
崔锷  骆常淞  刘忠  朱岳 《火灾科学》2020,29(1):49-55
利用计算机疏散模拟的手段,根据超高层建筑内基于国标GB50016-2014《建筑设计防火规范》要求设计的安全疏散系统,设计了合理的疏散场景,对超高层建筑内以防烟楼梯为主的安全疏散系统,进行了安全可靠性的技术分析,并针对国内消防业界对超高层建筑内增加一部疏散楼梯的强化措施的安全效益提出了探讨。  相似文献   
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