The angular momentum of galaxies (galaxy spin) contains rich information about the initial condition of the Universe, yet it is challenging to efficiently measure the spin direction for the tremendous amount of galaxies that are being mapped by the ongoing and forthcoming cosmological surveys. We present a machine learning based classifier for the Z-wise vs S-wise spirals, which can help to break the degeneracy in the galaxy spin direction measurement. The proposed Chirality Equivariant Residual Network (CE-ResNet) is manifestly equivariant under a reflection of the input image, which guarantees that there is no inherent asymmetry between the Z-wise and S-wise probability estimators. We train the model with Sloan Digital Sky Survey (SDSS) images, with the training labels given by the Galaxy Zoo 1 (GZ1) project. A combination of data augmentation tricks are used during the training, making the model more robust to be applied to other surveys. We find a $\sim\!30\%$ increase of both types of spirals when Dark Energy Spectroscopic Instrument (DESI) images are used for classification, due to the better imaging quality of DESI. We verify that the $\sim\!7\sigma$ difference between the numbers of Z-wise and S-wise spirals is due to human bias, since the discrepancy drops to $<\!1.8\sigma$ with our CE-ResNet classification results. We discuss the potential systematics that are relevant to the future cosmological applications.

这是机器学习中（主要是）笔和纸练习的集合。练习在以下主题上：线性代数，优化，定向图形模型，无向图形模型，图形模型的表达能力，因子图和消息传递，隐藏马尔可夫模型的推断，基于模型的学习（包括ICA和非正态模型），采样和蒙特卡洛整合以及变异推断。

在现实世界中，在雾度下拍摄的图像的降解可以是非常复杂的，其中雾度的空间分布从图像变化到图像。最近的方法采用深神经网络直接从朦胧图像中恢复清洁场景。然而，由于悖论由真正捕获的雾霾的变化和当前网络的固定退化参数引起的悖论，最近在真实朦胧的图像上的脱水方法的泛化能力不是理想的。解决现实世界建模问题阴霾退化，我们建议通过对不均匀雾度分布的鉴定和建模密度来解决这个问题。我们提出了一种新颖的可分离混合注意力（SHA）模块来编码雾霾密度，通过捕获正交方向上的特征来实现这一目标。此外，提出了密度图以明确地模拟雾度的不均匀分布。密度图以半监督方式生成位置编码。这种雾度密度感知和建模有效地捕获特征水平的不均匀分布性变性。通过SHA和密度图的合适组合，我们设计了一种新型的脱水网络架构，实现了良好的复杂性性能权衡。两个大规模数据集的广泛实验表明，我们的方法通过量化和定性地通过大幅度超越所有最先进的方法，将最佳发布的PSNR度量从28.53 DB升高到Haze4K测试数据集和在SOTS室内测试数据集中的37.17 dB至38.41 dB。