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罕见气候事件的概率估计：大型确定性计算机代码的推断
Estimating the probability of rare climate events: inference from a large deterministic computer code |
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| 课程网址: |
http://videolectures.net/aispds08_challenor_eprce/
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| 主讲教师: |
Peter Challenor
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| 开课单位: |
南安普托大学
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| 开课时间: |
2008-09-09
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| 课程语种: |
英语
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| 中文简介: |
人类排放的温室气体意味着我们能够预测未来的气候是至关重要的。这种可能的未来气候的一个方面被称为低概率高影响事件。其中包括我们希望不太可能发生的冰盖崩塌，但如果真的发生，将对气候产生非常重大的影响。我们解决这些问题的唯一方法是通过计算机模型，我们没有任何可用的数据。这样的模型非常大而且复杂，需要大量的计算机时间。因此，不能使用简单的蒙特卡罗推理方法。相反，我们使用统计方法来研究模型的性质。这些都是基于模拟器的概念。仿真器是在给定模型输入的情况下，对模型输出的统计近似，并包含对其自身不确定性的度量。我们的仿真器使用高斯过程，但原则上可以使用其他函数。构建了仿真器之后，我们可以使用它来执行推理，而不是使用计算机模型本身。我们将举例说明这些方法，以估计北大西洋热盐环流崩溃的风险，并讨论未来的改进。
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| 课程简介: |
Anthropogenic emission of greenhouse gases means that it is vital that we can predict future climates. One aspect of such possible future climates are so called low probability high impact events. These include things like the collapse of ice sheets that we hope are unlikely but if they did happen would have very major impacts on the climate. The only way we can address these problems is through computer models, we do not have any data that is applicable. Such models are very large and complex and require huge amounts of computer time. Thus simple Monte Carlo methods of inference cannot be used. Instead we use statistical methods to investigate the properties of the model. These are based around the concept of an emulator. An emulator is a statistical approximation to the model output given the model inputs, and includes a measure of its own uncertainty. We use Gaussian processes for our emulators but in principle other functions could be used. Having built an emulator we can use it to perform our inference rather than the computer model itself. We will illustrate these methods to estimate the risk of the collapse of the thermohaline circulation in the North Atlantic and discuss future improvements.
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| 关 键 词: |
罕见气候; 概率估计; 计算机代码
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| 课程来源: |
视频讲座网
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| 最后编审: |
2020-06-08：heyf
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| 阅读次数: |
56
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