论文标题

部分可观测时空混沌系统的无模型预测

Sponsored messaging about climate change on Facebook: Actors, content, frames

论文作者

Weaver, Iain, Westwood, Ned, Coan, Travis, O'Neill, Saffron, Williams, Hywel T. P.

论文摘要

储层计算是预测湍流的有力工具,其简单的架构具有处理大型系统的计算效率。然而,其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间,然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用,该系统模拟了湍流的若干特征。我们表明,使用径向基函数作为非线性投影器,即使只有部分观测并且不知道控制方程,也能稳健地捕捉复杂的系统非线性。最后,我们表明,当测量稀疏、不完整且带有噪声,甚至控制方程变得不准确时,我们的网络仍然可以产生相当准确的预测,从而为实际湍流系统的无模型预测铺平了道路。

Online communication about climate change is central to public discourse around this contested issue. Facebook is a dominant social media platform known to be a major source of information and online influence, yet discussion of climate change on the platform has remained largely unstudied due to difficulties in accessing data. This paper utilises Facebook's repository of social/political ads to study how climate change is framed as an issue in adverts placed by different actors. Sponsored content is a strategic investment and presumably intended to be persuasive, so patterns of who pays for adverts and how those adverts frame the issue can reveal large-scale trends in public discourse. We show that most money spent on climate-related messaging is targeted at users in the US, GB and CA. While the number of advert impressions correlates with total spend by an actor, there is a secondary effect of unpaid social sharing which can substantially affect the number of impressions per dollar spent. Most spend in the US is by political actors, while environmental non-governmental organisations dominate spend in GB. Analysis shows that climate change solutions are well represented in GB, while climate change impacts such as extreme weather events are strongly represented in the US and CA. Different actor types frame the issue of climate change in different ways; political actors position the issue as party political and a point of difference between candidates, whereas environmental NGOs frame climate change as the focus of collective action and social mobilisation. Overall, our study provides a first empirical exploration of climate-related advertising on Facebook. It shows the diversity of actors seeking to use Facebook as a platform for their campaigns and how they utilise different topic frames to persuade users to act.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源