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221.
A.A. SiddiquiS.M.V. Gwynne 《Safety Science》2012,50(3):478-493
Simulation tools are often used to establish pedestrian and evacuee performance. The accuracy and reliability of such tools are dependent upon their ability to qualitatively and quantitatively capture the outcome of this performance; i.e. whether the simulated agents perform the expected acts and take the expected amount of time to complete them. This article investigates the relationship between simulating individual agent actions and generating reliable emergent conditions (e.g. congestion). Once this relationship is established for a particular tool, it can then be used to investigate the conditions that may emerge in certain scenarios and mitigate against them. This article presents a simple framework for categorising real-world observations and then translating these observations into the simulated environment - extracting key information from the data collected to configure the simulation tool as required. The article addresses the qualitative benefits of representing individual-level actions, and, to a lesser degree, the quantitative benefits, although this effort is limited given the nature of the data. It tests this relationship using observations made at the Hajj, specifically the Sa’ee where large numbers of pilgrims perform religious rites in concert. Several scenarios are simulated using the buildingEXODUS model, enabling the importance of individual-level behaviours upon emergent conditions to be investigated, even when simulating relatively large crowds of up to 15,000 people. 相似文献
222.
Quantification of land use/land cover changes in Pearl River Delta and its impact on regional climate in summer using numerical modeling 总被引:2,自引:0,他引:2
Wenshi Lin Lu Zhang Dongsheng Du Limin Yang Hui Lin Yuanzhi Zhang Jiangnan Li 《Regional Environmental Change》2009,9(2):75-82
This study quantified land use/land cover (LULC) changes in Pearl River Delta (PRD) of South China and its impact on regional
climate over the last two decades. The LULC change analyses were accomplished by applying a change detection method to a set
of Landsat imagery and ancillary data acquired from 1970s to 2000. The results indicate that the urban expansion is the prevailing
LULC change in the PRD. Impact of LULC change on regional climate was simulated by using a mesoscale climate model. Two different
land cover datasets circa 1990 and 2000 were input to the model to investigate the impact of urbanization on regional weather
and climate condition in summer 2005. The simulation results show that rapid urban expansion can substantially alter regional
climate conditions in the PRD region including monthly mean temperature, precipitation, moisture, and surface heat fluxes. 相似文献
223.
古建筑的消防安全工作作为古建筑保护工作内容的重要组成部分,需要深入开展的消防科学的研究工作.目前在我国,缺少关于古建筑防火安全方面的规范,通常使用的处方式规范一般不适用于古建筑.性能化方法能够提供更加灵活和符合实际的解决方案.并且这可能是唯一可行的使古建筑达到可接受风险水平的方法.以布达拉宫东大殿为研究对象,探讨了性能化防火分析方法在古建筑防火保护中的应用.以对古建筑进行早期探测报警为目标进行了消防设施设置.应用FDS软件进行了模拟研究,根据模拟结果进行分析,得到了一些有益的结论并应用于消防设施设置.通过对探测器响应时间分析,探测器的设置合理,能够在第一时间报警,并且实现了消防安全设计的科学化、合理化和成本效益的最优化. 相似文献
224.
Ebrayi KN Pathak H Kalra N Bhatia A Jain N 《Environmental monitoring and assessment》2007,131(1-3):451-465
Nitrogen is the most widely used fertilizer nutrient, and it is a universally deficient nutrient too, which often severely
restricts the growth and yield of crops. To improve N fertilizer management, soil–plant system models can be applied to simulate
adequate N supply for both, optimal crop growth and minimal N losses. The likely impact of climate change on the cereal production
is of paramount importance in the planning strategies to meet the future growing needs on sustainable grounds. In this scenario
models are the effective tools to foresee the probable impacts and for choosing appropriate land use options. The study reported
in this thesis, employs field experiments and use of simulation tools to understand the dynamics of soil N balance and relate
growth and yield of rice under varying nitrogen inputs. The InfoCrop model was used in this study, which was calibrated with
the historic data sets, and subsequently validated with the field experiment conducted at IARI Farm, New Delhi. Simulated
results matched well with the observed values in terms of growth and yield of rice and seasonal nitrogen uptake. The components
of soil nitrogen balance differed among varying nitrogen level treatments, which was also captured by use of InfoCrop. The
model was then taken to climate change impact analysis. The results clearly revealed that when temperature increased, the
soil N losses, like denitrification, volatilization, N2O emission increased, whereas grain and biomass yields decreased. The
further scope of the study is to validate the study in contrasting agroenvironments. 相似文献
225.
We develop a reserve design strategy to maximize the probability of species persistence predicted by a stochastic, individual-based,
metapopulation model. Because the population model does not fit exact optimization procedures, our strategy involves deriving
promising solutions from theory, obtaining promising solutions from a simulation optimization heuristic, and determining the
best of the promising solutions using a multiple-comparison statistical test. We use the strategy to address a problem of
allocating limited resources to new and existing reserves. The best reserve design depends on emigration, dispersal mortality,
and probabilities of movement between reserves. When movement probabilities are symmetric, the best design is to expand a
subset of reserves to equal size to exhaust the habitat budget. When movement probabilities are not symmetric, the best design
does not expand reserves to equal size and is strongly affected by movement probabilities and emigration rates. We use commercial
simulation software to obtain our results. 相似文献
226.
Simulation and evaluation on the eco-industrial system of Changchun economic and technological development zone, China 总被引:2,自引:0,他引:2
Reasonable structure, adaptive patterns and effective regulation of society, economy and environment subsystems should be
taken into account in order to obtain harmonious development of urban eco-industrial system. We simulated and evaluated a
redesigned eco-industrial system in Changchun Economic and Technological Development Zone (CCETDZ) in the present work using
system dynamics and grey cluster methods. Four typical development strategies were simulated during 2005–2020 via standard
system dynamic models. Furthermore, analytic hierarchy process and grey cluster allowed for the eco-industrial system evaluation
and scenarios optimizing. Our dynamic simulation and statistical analysis revealed that: (1) CCETDZ would have different development
scenarios under different strategies. The total population in scenario 2 grew most rapidly and reached 3.28 × 105 in 2020, exceeding its long-term planning expected population. And the GDP differences among these four scenarios would amount
to 6.41 × 1010 RMB. On the other hand, environmental pollution would become serious along with economy increasing. As a restriction factor,
positive or negative increment of water resource will occur according to the selected strategy. (2) The fourth strategy would
have the best efficiency, which means that the most efficiently development of CCETDZ required to take science, technology,
environment progress and economy increase into account at the same time. (3) Positive environment protection measures, such
as cleaner production, green manufacture, production life cycle management and environment friendly industries, should be
attached great importance the same as economy development during 2005–2020 in CCETDZ. 相似文献
227.
Developing countries struggle to provide adequate urban water services, failing to match infrastructure with urban expansion. Despite requiring an improved understanding of alternative infrastructure performance when considering future investments, integrated modeling of urban water systems is infrequent in developing contexts. This paper presents an integrated modeling methodology that can assist strategic planning processes, using Port Vila, Vanuatu, as a case study. 49 future model scenarios designed for the year 2050, developed through extensive stakeholder participation, were modeled with UVQ (Urban Volume and Quality). The results were contrasted with a 2015 model based on current infrastructure, climate, and water demand patterns. Analysis demonstrated that alternative water servicing approaches can reduce Port Vila’s water demand by 35 %, stormwater generation by 38 %, and nutrient release by 80 % in comparison to providing no infrastructural development. This paper demonstrates that traditional centralized infrastructure will not solve the wastewater and stormwater challenges facing rapidly growing urban cities in developing countries. 相似文献
228.
Lars ?stlund Greger H?rnberg Thomas H. DeLuca Lars Liedgren Peder Wikstr?m Olle Zackrisson Torbj?rn Josefsson 《Ambio》2015,44(6):508-520
Anthropogenic deforestation has shaped ecosystems worldwide. In subarctic ecosystems, primarily inhabited by native peoples, deforestation is generally considered to be mainly associated with the industrial period. Here we examined mechanisms underlying deforestation a thousand years ago in a high-mountain valley with settlement artifacts located in subarctic Scandinavia. Using the Heureka Forestry Decision Support System, we modeled pre-settlement conditions and effects of tree cutting on forest cover. To examine lack of regeneration and present nutrient status, we analyzed soil nitrogen. We found that tree cutting could have deforested the valley within some hundred years. Overexploitation left the soil depleted beyond the capacity of re-establishment of trees. We suggest that pre-historical deforestation has occurred also in subarctic ecosystems and that ecosystem boundaries were especially vulnerable to this process. This study improves our understanding of mechanisms behind human-induced ecosystem transformations and tree-line changes, and of the concept of wilderness in the Scandinavian mountain range.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-015-0634-z) contains supplementary material, which is available to authorized users. 相似文献229.
采用谐振式紊动模拟装置使污染泥沙受到扰动,解吸重金属污染物进行模拟试验研究。在此基础上,由极坐标下的重金属迁移转化数学模型方程,针对具体的试验条件进行数值求解。计算和试验结果吻合良好。说明数学模型是正确合理的。计算中采用由静态试验得出的泥沙吸附-解吸特性参数,这对于评价静态试验成果,利用静态试验成果于天然河流水体具有一定的参考价值。 相似文献
230.