标题： 利用极值理论预测城市天际线 显示英文标题

标题： Forecasting the Urban Skyline with Extreme Value Theory

摘要： 到2050年，世界城市人口预计将增长百分之五十，并超过六十亿。 城市面临的主要挑战，如可持续性、安全性和平等性，将取决于为适应这一增长而开发的基础设施。 城市规划师长期以来一直在争论垂直扩张——通过建造高层建筑集中居民——与水平扩张——通过扩展城市边界分散居民——的后果。 然而，相对较少的研究预测了城市的垂直扩张并量化了这些后果的可能性和紧迫性。 我们将高层建筑视为超过某个阈值的随机超越，并使用极值理论来预测如果当前趋势继续，到2050年将主导城市天际线的摩天大楼。 我们预测将有四万一千座超过150米高且有40层以上的摩天大楼，年增长率将达到百分之八，远超预期的城市人口年增长率百分之二。 典型的高层摩天大楼不会显著更高，而最高的摩天大楼可能超过一千米但不会达到一英里。 如果建造了一英里高的摩天大楼，它将容纳少于许多目前设计的一英里高的摩天大楼的居住者。 我们预测它的楼层数大约是一英里高塔楼的四分之三，是东京天空千米塔的三分之二，是弗兰克·劳埃德·赖特的伊利诺伊州大厦的一半——这三个是一英里高摩天大楼的著名设计方案。 然而，楼层与高度之间的关系将在不同城市之间有所差异。 显示英文摘要

摘要： The world's urban population is expected to grow fifty percent by the year 2050 and exceed six billion. The major challenges confronting cities, such as sustainability, safety, and equality, will depend on the infrastructure developed to accommodate the increase. Urban planners have long debated the consequences of vertical expansion---the concentration of residents by constructing tall buildings---over horizontal expansion---the dispersal of residents by extending urban boundaries. Yet relatively little work has predicted the vertical expansion of cities and quantified the likelihood and therefore urgency of these consequences. We regard tall buildings as random exceedances over a threshold and use extreme value theory to forecast the skyscrapers that will dominate the urban skyline in 2050 if present trends continue. We predict forty-one thousand skyscrapers will surpass 150 meters and 40 floors, an increase of eight percent a year, far outpacing the expected urban population growth of two percent a year. The typical tall skyscraper will not be noticeably taller, and the tallest will likely exceed one thousand meters but not one mile. If a mile-high skyscraper is constructed, it will hold fewer occupants than many of the mile-highs currently designed. We predict roughly three-quarters the number of floors of the Mile-High Tower, two-thirds of Next Tokyo's Sky Mile Tower, and half the floors of Frank Lloyd Wright's The Illinois---three prominent plans for a mile-high skyscraper. However, the relationship between floor and height will vary across cities.