Efficient traffic signal control (TSC) has been one of the most useful ways for reducing urban road congestion. By modeling each intersection as an autonomous agent, multiagent reinforcement learning (MARL) shows remarkable performance in solving dynamic TSC. However, most of TSC methods based on MARL suffer from a non-stationarity problem since agents update their policies simultaneously. To resolve this issue, this paper considers multi-intersection TSC as a multi-agent sequential decision-making process with policy online learning. We utilize a sequential model such as Transformer architecture to learn the multi-agent joint policy. By carefully designing the advantage function of each agent, the monotonic improvement property can be guaranteed. Moreover, to fully exploit the advantages of both simultaneous and sequential MARL, we further propose a novel MARL network selection algorithm (MARL-NS) which selectively employs simultaneous MARL only at states that sequential MARL might fall into local optimum. Our theory proves that MARL-NS preserves cooperative MARL converge properties. Finally, we validate the proposed MARL-NS method on a unified TSC benchmark, LibSignal. Experimental results show that our method can outperform the baseline methods in network-level and arterial coordination.

Preserving important textures of the content image and achieving prominent style transfer results remains a challenge in the field of image style transfer. This challenge arises from the entanglement between color and texture during the style transfer process. To address this challenge, we propose an end-to-end network that incorporates adaptive weighted least squares (AWLS) filter, iterative least squares (ILS) filter, and channel separation. Given a content image ($\mathcal {C}$) and a reference style image ($\mathcal {S}$), we begin by separating the RGB channels and utilizing ILS filter to decompose them into structure and texture layers. We then perform style transfer on the structural layers using WCT$^{2}$(incorporating wavelet pooling and unpooling techniques for whitening and coloring transforms) in the R, G, and B channels, respectively. We address the texture distortion caused by WCT$^{2}$with a texture enhancing (TE) module in the structural layer. Furthermore, we propose an estimating and compensating for the structure loss (ECSL) module. In the ECSL module, with the AWLS filter and the ILS filter, we estimate the texture loss caused by TE, convert the loss of the structural layer to the loss of the texture layer, and compensate for the loss in the texture layer. The final structural layer and the texture layer are merged into the channel style transfer results in the separated R, G, and B channels into the final style transfer result. Thereby, this enables a more complete texture preservation and a significant style transfer process. To evaluate our method, we utilize quantitative experiments using various metrics, including NIQE, AG, SSIM, PSNR, and a user study. The experimental results demonstrate the superiority of our approach over the previous state-of-the-art methods.

The problem of color and texture distortion remains unsolved in the photorealistic style transfer task. It is mainly caused by the interference between color and texture during transferring. To address this problem, we propose a end-to-end network via adaptive filtering and channel separation. Given a pair of content image and reference image, we firstly decompose them into two structure layers through adaptive weighted least squares filter (AWLSF), which could better perceive the color structure and illumination. Then, we carry out RGB transfer in a channel separation way on the two generated structure layers. To deal with texture in a relatively independent manner, we use a module and a subtraction operation to get more complete and clear content features. Finally, we merge the color structure and texture detail into the ultimate result. We conduct solid quantitative experiments on four metrics NIQE, AG, SSIM, and PSNR, and make a user study. The experimental results demonstrate that our method is able to produce better results than previous state-of-the-art methods, and validate the effectiveness and superiority of our method.

Summary Recently, a new intelligent algorithm called animal migration optimization (AMO) is proposed. The AMO algorithm, which is inspired by the behavior of animal migration, exhibits good performance on a series of benchmark functions whose dimensionality is less than or equal to 30. However, its performance deteriorates evidently when the dimensionality is more than 30. To overcome this drawback, we proposed an improved AMO (IAMO) with interactive learning mechanism in this article. First, an interactive learning mechanism is designed to improve the intelligence of AMO. During the the search process, individuals learn from each other by the exchange of information, and the search mode is adjusted dynamically. Second, a refined search method is adopted to enhance the search ability of AMO. Individuals will search around the current solutions in order to improve the quality of solutions. Third, a birth‐and‐death strategy is introduced to avoid local optimum. In addition, the property convergence of IAMO is analyzed theoretically. The proposed algorithm is validated on several standard benchmark functions whose dimensionality is 50, 100, and 150, respectively. The empirical results demonstrate that the performance of our proposed algorithm is promising.