Models, code, and papers for "Jason Hickey":

Machine Learning for Precipitation Nowcasting from Radar Images

Dec 11, 2019
Shreya Agrawal, Luke Barrington, Carla Bromberg, John Burge, Cenk Gazen, Jason Hickey

High-resolution nowcasting is an essential tool needed for effective adaptation to climate change, particularly for extreme weather. As Deep Learning (DL) techniques have shown dramatic promise in many domains, including the geosciences, we present an application of DL to the problem of precipitation nowcasting, i.e., high-resolution (1 km x 1 km) short-term (1 hour) predictions of precipitation. We treat forecasting as an image-to-image translation problem and leverage the power of the ubiquitous UNET convolutional neural network. We find this performs favorably when compared to three commonly used models: optical flow, persistence and NOAA's numerical one-hour HRRR nowcasting prediction.


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Data-driven metasurface discovery

Nov 29, 2018
Jiaqi Jiang, David Sell, Stephan Hoyer, Jason Hickey, Jianji Yang, Jonathan A. Fan

A long-standing challenge with metasurface design is identifying computationally efficient methods that produce high performance devices. Design methods based on iterative optimization push the performance limits of metasurfaces, but they require extensive computational resources that limit their implementation to small numbers of microscale devices. We show that generative neural networks can learn from a small set of topology-optimized metasurfaces to produce large numbers of high-efficiency, topologically-complex metasurfaces operating across a large parameter space. This approach enables considerable savings in computation cost compared to brute force optimization. As a model system, we employ conditional generative adversarial networks to design highly-efficient metagratings over a broad range of deflection angles and operating wavelengths. Generated device designs can be further locally optimized and serve as additional training data for network refinement. Our design concept utilizes a relatively small initial training set of just a few hundred devices, and it serves as a more general blueprint for the AI-based analysis of physical systems where access to large datasets is limited. We envision that such data-driven design tools can be broadly utilized in other domains of optics, acoustics, mechanics, and electronics.

* 14 pages, 5 figures 

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MetNet: A Neural Weather Model for Precipitation Forecasting

Mar 30, 2020
Casper Kaae Sønderby, Lasse Espeholt, Jonathan Heek, Mostafa Dehghani, Avital Oliver, Tim Salimans, Shreya Agrawal, Jason Hickey, Nal Kalchbrenner

Weather forecasting is a long standing scientific challenge with direct social and economic impact. The task is suitable for deep neural networks due to vast amounts of continuously collected data and a rich spatial and temporal structure that presents long range dependencies. We introduce MetNet, a neural network that forecasts precipitation up to 8 hours into the future at the high spatial resolution of 1 km$^2$ and at the temporal resolution of 2 minutes with a latency in the order of seconds. MetNet takes as input radar and satellite data and forecast lead time and produces a probabilistic precipitation map. The architecture uses axial self-attention to aggregate the global context from a large input patch corresponding to a million square kilometers. We evaluate the performance of MetNet at various precipitation thresholds and find that MetNet outperforms Numerical Weather Prediction at forecasts of up to 7 to 8 hours on the scale of the continental United States.


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