A Monte-Carlo approach to estimating the effects of selected airport capacity options in London

The issue of future airport capacity in London is currently the subject of much political debate in the UK. Although realistic estimates of the effects of capacity enhancement may be desirable, such estimates are difficult. Through the use of Monte Carlo simulation, this paper quantifies and compares the relative capacity enhancements that may be afforded by the construction of a new hub airport in the Thames Estuary, additional runways at Heathrow, Gatwick and Stansted and changes to operating practices at Heathrow. The simulations show that a new hub airport would be the most effective way to increase capacity, although the reported financial and environmental costs of such a development indicate a comparatively poor rate of return. Proposed new runways at Heathrow, Gatwick and Stansted and the removal of runway alternation at Heathrow provide more modest increases in capacity.     

Economic Impacts of Improved Connectivity for ASEAN: An Application of the Geographical Simulation Model

We compare the prioritized projects of the Master Plan on ASEAN Connectivity (MPAC) and the Comprehensive Asia Development Plan (CADP) by utilizing the Institute of Developing Economies/Economic Research Institute for ASEAN and East Asia Geographical Simulation Model. The prioritized projects of the MPAC mainly focus on specific hard or soft infrastructure projects connecting one remote area of an ASEAN member state to another and thus fail to capture the full potential of the infrastructure because of neglected important links within a state. On the other hand, the CADP emphasizes the importance of economic corridors or linkages between a large cluster and another cluster. Our simulation analysis shows that CADP projects will result in an addition to gross domestic product (GDP) of $US 1544bn over the period from 2021 to 2030 (in 2010 dollars) or an impact on ASEAN countries that is 12 times larger than MPAC projects. The results strongly suggest that the CADP projects should be adopted and implemented to fully realize the potential economic growth of the ASEAN countries. Moreover, the CADP will contribute more to narrowing the development gaps among the ASEAN countries than MPAC prioritized projects.     

Designing futures: Inquiry in climate change communication

There are many barriers and challenges associated with climate change communication focused on promoting community-based action for sustainable futures. Of particular interest is the challenge to embed community perspectives in a communication process of climate change solutions. In this paper we argue that 3D interactive simulations using design inquiry as a development process, can be an effective way of communicating climate change solutions and multiple community responses. People are more likely to engage with the challenges associated with complexity of climate change at the local level when their perspectives are integrated into viable and multiple pathways for action. Future scenarios of change processes situated in local experiences in compelling and interactive ways can be disseminated holistically by making links between scientific, social, political, economic and cultural elements. Design inquiry, as a research approach, integrates contextual knowledge into communication processes to aid imagining, re-thinking and reembodying viable pathways that explore the kinds of futures we collectively envision. This paper examines the contributions that design inquiry makes to climate change communication using an interactive simulation environment for designing futures. We discuss these ideas using the example of the Future Delta project, a virtual 3D environment that enables the exploration and simulation of multiple community-based climate change solutions in the Corporation of Delta, British Columbia.     

基于多智能体的城市生态保护红线多情景模拟

生态红线划定是城市可持续发展的基础,目前的生态红线划定主要采用国家生态红线划分标准来进行,没有考虑与城市建设用地空间的相互协调,为了解决这一问题,以多智能体系统理论为基础构建"城市建设用地—生态保护红线"协调的决策模型,协调城市建设发展与生态环境保护的现实需要,确定不同保护和发展模式下的城市生态红线。以鄂州市作为研究区域进行实验,模拟了不同生态保护模式下的生态保护红线划定情况,结果表明在生态红线划定中考虑多主体的决策因素有助于协调优化城市生态环境保护与城市发展的矛盾。     

农村集体建设用地空间研究进展与展望

我国农村集体建设用地空间布局混乱,而现有关于农村集体建设用地空间研究方面存在理论与方法缺陷。文章对农村集体建设用地空间格局及机制、农村集体建设用地的空间优化、城乡建设用地统一空间研究领域相关研究进展进行综述,结论为现有研究存在理论体系尚未建立、研究内容不健全、研究方法以定性描述和空间描述为主等问题。建议未来该领域研究应跳出传统土地管理相关理论,多学科交叉,探索地理学、经济学在农村集体建设用地空间研究方面的理论框架;基于空间格局—演变机制—优化配置的思路,构建农村集体建设用地空间格局演变动力模型、农村集体建设用地空间与人口/产业的相互影响模型、城乡建设用地统一空间模型,从农村集体建设用地空间格局及其演变机制、农村集体建设用地空间与人口/产业的协调机制、城乡联系机制下的农村集体建设用地空间优化3方面来开展农村集体建设用地空间研究。     

基于不同Logistic模型的土地利用格局模拟对比研究——以湖北省宣恩县和咸丰县为例

模拟土地利用空间格局分布规律对合理利用土地资源、制定土地利用规划、协调土地与经济、环境的关系具有十分重要的意义。土地利用格局存在空间异质性,对比不同地区格局特征规律对加深土地利用格局的认识具有重要意义。以邻接的湖北省宣恩县和咸丰县为研究对象,通过对比基于局地因子、自相关因子和邻域因子的3种Logistic模型的模拟参数的一致性和异质性来对比研究两地的格局分布规律。实验与分析结果表明,宣恩县和咸丰县的土地利用格局特征存在共同的驱动因子和聚集效应,具有共性;不同模型的模拟结果表明驱动因子在作用方向,大小方面存在差异,邻域因子在邻域尺度上表现出不同特征。研究结果对加深理解不同地区的土地利用分布格局特征的差异性,促进区域土地利用的规划、土地资源的合理开发与可持续发展战略的顺利实施具有一定的参考价值。     

Study of emerging air taxi network operation using discrete-event systems simulation approach

This research focuses on understanding the air taxi operations to determine the number of air taxis required to fulfill the demand for urban air mobility in New York City (NYC). We leverage the Define, Measure, Analyze, Design, and Verify (DMADV) framework and integrate it with the systems simulation approach. Upon investigation, we find that all the parameters linearly impact the vehicle utilization, while other measures are robust, specifically with respect to the seating capacity. It is also recommended to operate initially with 70 air taxis in NYC to achieve a trade-off between customer wait time and vehicle utilization. The proposed approach can act as a recommender system for air taxi companies.     

Exploring the impact of the physical conditions of mannequin displays on mental simulation: An embodied cognition theory perspective

This study examines how mannequins' physical conditions of display height and distance are related to consumers’ shopping motivations in generating mental simulation resulting in purchase intention. A 2 × 2 x 2 between-subjects lab experiment (n = 249) was conducted to address this question. The results reveal a significant three-way interaction effect of display height, distance, and shopping motivation. Specifically, it is found that for those with a dominant hedonic shopping motivation, a mannequin displayed up high generates greater mental simulation than one displayed down low, but for those with a dominant utilitarian shopping motivation, a mannequin displayed high and close to consumers generates greater mental simulation than one displayed low and close to them. This study also reveals that mental simulation mediates the influence of the interaction effect of “display height x distance,” moderated by shopping motivation, on purchase intention. Important theoretical and practical implications for retail managers are discussed.     

基于SD模型的诸城市农业结构仿真优化研究

［目的］预测2017—2035年诸城市农业结构的变化趋势，对农业结构进行多情景优化仿真，提出优化调整建议。［方法］文章以山东省诸城市作为研究对象，将农业结构划分为种植、种养结合和加工休闲3个子系统，选取56个指标，运用多元统计回归分析等方法构建41个方程，建立农业结构系统动力学（System Dynamics，简称SD）模型，运用Vensim—PLE软件进行仿真优化分析。［结果］SD模型预测结果表明，到2035年，粮食作物播种面积1105万hm2，总产量8037万t，经济作物播种面积652万hm2，总产量15203万t； 生猪出栏量达到29615万头，家禽出栏量1105 231亿只，畜禽粪污利用率8792%； 农业总产值达到25132亿元，休闲农业产值6134亿元，食品加工业产值1 25263亿元。假设种植业生产中的农业科技投入增加2个百分点， 2035年粮食作物产量较优化前增加576万t； 经济作物产量较优化前增加2814万t； 假设有机肥施用补贴增加3个百分点， 2035年畜禽粪污利用率较优化前提高762个百分点； 假设农产品加工业的研发力度和科技投入增加1个百分点， 2035年食品加工产值较优化前增加73521亿元； 农产品加工业产值占农业总产值比值由优化前的325：1达到41：1。［结论］为进一步推进诸城市农业结构调整，迫切需要加大农业科技投入，完善有机肥扶持政策，培育种养结合新型经营主体，重点扶持培育加工龙头企业，发展现代化休闲农场，促进农业产业融合发展。     

基于fluent紊流幂律流体偏心环空数值模拟研究

为解决常规钻井水力学公式对偏心流场计算结果与实际有所差别的问题,揭示大位移井偏心环空水力行为规律,基于fluent软件对幂律钻井液偏心环空紊流流动进行了数值模拟研究,分析偏心度、稠度系数、流性指数、屈服值、钻杆与钻头组合对流动规律的影响.结果表明,随偏心度、稠度系数、流性指数、屈服值、钻杆与钻头尺寸比例的增大,环空中宽间隙处的流速、压力逐渐增大,而窄间隙处的流速、压力逐渐减小.