Features are important for polarimetric synthetic aperture radar (PolSAR) image classification. Various methods focus on extracting feature artificially. Compared with them, we have developed a method to learn feature automatically. The method is based on deep learning which can learn multilayer features. In this paper, stacked sparse autoencoder (SAE) as one of the deep learning models is applied as a useful strategy to achieve the goal. For improving the classification result, we use a small amount of labels to fine-tuning the parameters of the proposed method. Finally, a real PolSAR dataset is used to verify the effectiveness. Experiment result confirms that the proposed method provides noteworthy improvements in classification accuracy and visual effect.

Intelligent generation of time‐variant control series remains the critical challenge for acquiring the desired system evolution, due to the difficulties in perceiving temporal correlation and conducting appropriate feedback propagation. A machine learning (ML) algorithm named time‐series generative adversarial network (TSGAN) is developed to overcome the difficulties, by incorporating a long short‐term memory (LSTM) kernel for recognizing multirange temporal patterns beyond the Markovian approximation and an adversarial training mechanism for efficient optimization. A variety of time series are examined by temperature‐control experiments, and the results demonstrate an exceptional accuracy (>95%, 35% higher than prevalent ML methods) as well as strong transferability and stability of the TSGAN algorithm. The dependence of generation performance on underlying statistical mechanisms associated with different ML algorithms, including the deep neural network (DNN), hidden Markov model (HMM), LSTM, and TSGAN, is elucidated by analyzing the generation quality of characteristic temporal patterns. The capability of generating arbitrarily complex response series opens an opportunity for inverse design of time‐variant functionals as strenuously pursued in material science and modern technology.

Super-resolution (SR) problem still faces a challenge of wisely utilizing diverse learned priors to recover the lost details in low resolution images. In this work, we propose a novel method using low rank decomposition which integrates diverse priors learned from external and internal learning to construct SR image. The proposed method first applies an external dictionary learning to get the meta-detail that is commonly shared among images, and then introduces an internal prior learning to learn the local self-similarity (local structure) that is shared in the image. Both are essential but different priors for SR image construction. With these priors, a bank of preliminary HR images are obtained but with estimation errors and noise. To restrain the errors and noise, we consider these HR images as a high dimension data in dimension reduction problem, and solve it using a low rank decomposition. Experimental results show the proposed method preserves image details effectively, also outperforms state-of-the-arts in both visual and quantitative assessments, especially in dealing with the noise.Index Terms-External dictionary learning, internal prior learning, low rank decomposition, image Super-Resolution.