Experience replay plays a crucial role in Reinforcement Learning (RL), enabling the agent to remember and reuse experience from the past. Most previous methods sample experience transitions using simple heuristics like uniformly sampling or prioritizing those good ones. Since humans can learn from both good and bad experiences, more sophisticated experience replay algorithms need to be developed. Inspired by the potential energy in physics, this work introduces the artificial potential field into experience replay and develops Potentialized Experience Replay (PotER) as a new and effective sampling algorithm for RL in hard exploration tasks with sparse rewards. PotER defines a potential energy function for each state in experience replay and helps the agent to learn from both good and bad experiences using intrinsic state supervision. PotER can be combined with different RL algorithms as well as the self-imitation learning algorithm. Experimental analyses and comparisons on multiple challenging hard exploration environments have verified its effectiveness and efficiency.

In this paper, we propose a novel image interpolation algorithm suitable for general scale enlargement. Different from previous AR-based interpolation algorithms which employ predetermined reference configuration to predict pixel values, we consider the context information when building AR models. Optimal references are selected by incorporating nonlocal-based correlation coefficient and the indicator for local edge direction. Furthermore, the multiplanar constraint among similar patches is applied to enhance the correlation within the estimation window and serves as a kind of supplement to data fidelity term in AR model. The experimental results show that our method is effective in several enlargement scales and successfully alleviate the artifacts nearby edges and preserve their sharpness. The comparison experiments demonstrate that the proposed method can obtain desirable performance in terms of both objective and subjective results.

Image and video super-resolution (SR) has been explored for several decades. However, few works are integrated into practical systems for real-time image and video SR. In this work, we present a real-time deep video SpaTial Resolution UpConversion SysTem (STRUCT++). Our demo system achieves real-time performance (50 fps on CPU for CIF sequences and 45 fps on GPU for HDTV videos) and provides several functions: 1) batch processing; 2) full resolution comparison; 3) local region zooming in. These functions are convenient for super-resolution of a batch of videos (at most 10 videos in parallel), comparisons with other approaches and observations of local details of the SR results. The system is built on a Global context aggregation and Local queue jumping Network (GLNet). It has a thinner and deeper network structure to aggregate global context with an additional local queue jumping path to better model local structures of the signal. GLNet achieves state-of-the-art performance for real-time video SR.

Deep learning-based image super-resolution has provided very impressive reconstruction quality. However, their running time still sets barriers for real-time applications. In this paper, we propose a Global context aggregation and Local queue jumping Network (GLNet) which provides the more effective image SR given a certain number of model parameters. In our GLNet, we reconsider the model design of the real-time image SR paradigm. Then, we construct a deep network with fewer channels but a deeper structure to effectively aggregate the global context. The dilated convolutions are used as parts of basic units of our GLNet, which further enlarges the receptive field. Besides, an additional local queue jumping path is employed to connect the first-layer feature map and the last-layer feature map to better model the local signal structure. Extensive experiments demonstrate the superiority of our GLNet which offers new state-of-the-art performance considering both reconstruction quality and time consumption.

In this paper, we propose a novel image interpolation algorithm by context-aware autoregressive (AR) model and multiplanar constraint. Different from existing AR based methods which employ predetermined reference configuration to predict pixel values, the proposed method considers the anisotropic pixel dependencies in natural images and adaptively chooses the optimal prediction context by utilizing the nonlocal redundancy to interpolate pixels. Furthermore, the multiplanar constraint is applied to enhance the correlations within the estimation window by exploiting the self-similarity property of natural images. Similar patches are collected by the combination of patch-wise pixel values and the gradient information. And the inter-patch dependencies are adopted to improve the interpolation. The experimental results show that our method is effective in image interpolation and successfully decreases the artifacts nearby the sharp edges. The comparison experiments demonstrate that the proposed method can obtain better performance than other related ones in terms of both objective and subjective results.

A high data transfer rate quadrature phase shift keying (QPSK) demodulator is proposed for wireless implantable electronic medical devices. The QPSK demodulator is an improved version from our previous binary phase shift keying (BPSK) demodulator, which is based on a modified Costas loop. Simulated QPSK model under Matlab Simulink obtained a data transmission rate of 8 Mbps with 13.56 MHz carrier frequency. Also, implemented differential topology of the proposed circuit using a 0.18/spl mu/m CMOS technology achieves a data transmission rate up to 4Mbps with the same carrier frequency. The simulated power dissipation of the schematic is 0.75mW under 1.8V power supply.