促进交通运输中的实验文化

交通系统随时可能发生各种变化。通过实验的方法研究这些变化有利于掌握其因果规律,并验证哪些行为有效、哪些行为无效。对实验室实验、分析模型、现场试验和自然实验四类实验进行介绍,提出通过从自然中学习、将事件变成实验、共享数据等促进交通运输研究中的实验文化。通过建立一种实验文化,既能进行现场实验,又可以利用自然实验的机会进行学习,进而对交通系统的脆弱性、项目和政策的适用性了解更多。

桑德拉的公寓

这间位于半山的公寓，有700平主英尺，设计师Gary Chang将Suitcased House的一些设计理念，应用到公寓设计中，屋主经常宴请宾客，因而Gary知道，这样一个不大的空间需要有很强的空间灵活性。

Connections between Operator-Splitting Methods and Deep Neural Networks with Applications in Image Segmentation

Deep neural network is a powerful tool for many tasks.Understanding why it is so successful and providing a mathematical explanation is an important problem and has been one popular research direction in past years.In the literature of mathematical analysis of deep neural networks,a lot of works is dedicated to establishing representation theories.How to make connections between deep neural networks and mathematical algorithms is still under development.In this paper,we give an algorithmic explanation for deep neural networks,especially in their connections with operator splitting.We show that with certain splitting strategies,operator-splitting methods have the same structure as networks.Utilizing this connection and the Potts model for image segmentation,two networks inspired by operator-splitting methods are proposed.The two networks are essentially two operator-splitting algorithms solving the Potts model.Numerical experiments are presented to demonstrate the effectiveness of the proposed networks.

Peter Zumthor 一首洗炼的诗

每次看见Peter Zumthor的作品,我总在想象,我们有没有可能有这样的建筑:以效率和密集先行的城市,又是否可以容得下一个像他这样,每一个作品动辄费上十年时间的建筑师。将香港和欧洲瑞士去作比较,也许是不切实际的事,虽然香港跟瑞士有着相近的人口数目。然而这位以"rich but restraint modernism",作品每每如一首用字造句极度洗炼的诗歌的瑞士裔建筑大师,作风明显地比现下足迹遍及全球的"star architect"们来得更低调,其创作上的思维,说不定也可以对香港这个以反应快和效率高,却每每缺乏深层的内蕴,可堪玩昧的细节,甚至精准专业性的城市,有一点点启示。就让我们由他新近完成,位于德国科隆市内的Kolumba Museum开始,慢慢游,细意咀嚼。