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Two improved anisotropic Liouville type theorems for the stationary 3D Navier–Stokes equations

Archiv der Mathematik 2025年第5期124卷 571-582页

作者： Zhang, Zhibing Zu, Qian School of Mathematics and Physics Key Laboratory of Modeling Simulation and Control of Complex Ecosystem in Dabie Mountains of Anhui Higher Education Institutes Anqing Normal University Anqing 246133 China School of Mathematics and Statistics Anhui Normal University Wuhu 241002 China School of Mathematics and Physics Anqing Normal University Anqing 246133 China

In this paper, we establish two new anisotropic Liouville type theorems for the stationary 3D Navier–Stokes equations. Under certain anisotropic integrability conditions on the components of the velocity, we show that the solution is trivial. Our results extend and improve the results of Chae (Appl Math Lett 142:108655, 2023) and Luo and Yin (Arch Ration Mech Anal 224:209–231, 2017). © Springer Nature Switzerland AG 2025.

关键词： Anisotropic Liouville type theorem Stationary Navier–Stokes equations

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Maximization of k-Submodular Function with d-Knapsack Constraints Over Sliding Window

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Tsinghua Science and Technology 2025年第2期30卷 488-498页

作者： Wenqi Wang Yuefang Sun Zhiren Sun Donglei Du Xiaoyan Zhang School of Mathematical Science&Institute of Mathematics Nanjing Normal UniversityNanjing 210023China Key Laboratory of Ministry of Education Numerical Simulation of Large Scale Complex Systems Nanjing 210023China School of Mathematics and Statistics Ningbo UniversityNingbo 315211China Faculty of Management University of New BrunswickFredericton E3B9Y2Canada

Submodular function maximization problem has been extensively studied recently.A natural variant of submodular function is k-submodular function,which has many applications in real life,such as influence maximization and sensor placement *** domain of a k-submodular function has k disjoint subsets,and hence includes submodular function as a special case when k=*** work investigates the k-submodular function maximization problem with d-knapsack constraints over the sliding *** on the smooth histogram technique,we design a deterministic approximation ***,we propose a randomized algorithm to improve the approximation ratio.

关键词： k-submodular function d-knapsack constraints sliding window streaming algorithm approximation algorithm

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HRSTORY: Historical News Review Based Online Story Discovery 25

HRSTORY: Historical News Review Based Online Story Discovery

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Proceedings of the 31st ACM SIGKDD Conference on Knowledge Discovery and Data Mining V.1

作者： Renjie Zhou Haoran Ye Jian Wan Yong Liao Key Laboratory of Complex Systems Modeling and Simulation of the Ministry of Education Hangzhou Dianzi University Hangzhou Zhejiang China Zhejiang University of Science and Technology Hangzhou Zhejiang China University of Science and Technology of China Hefei Anhui China

ISBN: (纸本)9798400712456

Story discovery on news streams can help people quickly find story from vast amounts of news, improving the efficiency of information acquisition. Recent online story discovery methods encode text topics and then cluster articles into stories based on similarity. However, the results obtained by these methods are one-time, and clustered news cannot adaptively update in a continuous news stream. Additionally, the inadequate quality of article encoding and the presence of noise data deteriorate the performance of story discovery. To this end, we propose HRSTORY for online story discovery on news streams, which employs a historical news review method to enable news to continuously adapt to the latest environment in the stream data and make corrections and updates. Furthermore, HRSTORY captures better article embeddings through modeling multi-layer relational dependencies within the text. By using sentence-level noise masking, HRSTORY improves the relevance of news article representation to core topics and reduces the interference of noise data. Experiments on real news datasets show that HRSTORY outperforms the state-of-the-art algorithms in unsupervised online story discovery performance.

关键词： historical news

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NEW LIOUVILLE TYPE THEOREMS FOR 3D STEADY INCOMPRESSIBLE MHD EQUATIONS AND HALL-MHD EQUATIONS

arXiv

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arXiv 2025年

作者： Zhang, Zhibing School of Mathematics and Physics Key Laboratory of Modeling Simulation and Control of Complex Ecosystem in Dabie Mountains of Anhui Higher Education Institutes Anqing Normal University Anqing246133 China

In this paper, we study Liouville type results for the three-dimensional stationary incompressible MHD equations and Hall-MHD equations. By a new iteration argument, we establish Liouville type theorems if the velocity and magnetic field satisfy certain growth conditions of Lebesgue norms on the annulus. In our iteration procedure, the L2 norms of the gradients of the velocity and magnetic field and the L6 norms of the velocity and magnetic field are iterated together. The conditions imposed on the magnetic field are weaker than the velocity field in certain sense. As a consequence, we show that the velocity and magnetic field are trivial provided that they belong to some Lebesgue spaces or satisfy some decay conditions at infinity. Our results extend and improve the recent works of Chae-Lee (2024 Nonlinearity 37 095006) and Cho-Neustupa-Yang (2024 Nonlinearity 37 035007).MSC Codes 76W05, 76D03, 76D05 Copyright © 2025, The Authors. All rights reserved.

关键词： Liouville equation

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Multi-scale Dilated Attention-based Generative Adversarial Network for Infrared and Visible Image Fusion

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Current Optics and Photonics 2025年第2期9卷 120-129页

作者： Shunyuan Yang Xiaoping Shi Ju Huo Kangjian Sun Yu Wang School of Astronautics Harbin Institute of Technology Harbin 150001China National Key Laboratory of Modeling and Simulation for Complex Systems Harbin 150001China School of Electrical Engineering and Automation Harbin Institute of Technology Harbin 150001China Shanghai Space Propulsion Technology Research Institute Shanghai 201109China

In the field of optics, infrared and visible images are often required for use in different situations. In particular, in the field of optical sensors, infrared and visible sensors are mainly used to obtain different band images, which are applied to improve the comprehensive information content of images and to improve the quality and availability of images. In existing infrared and visible image fusion methods, the focus is often placed on retaining the background information from visible images and the salient targets from infrared images. To address this issue, we introduce a multi-scale dilated attention module into the encoder-decoder structure of the generator. By applying dilated convolution and self-attention mechanisms, this module improves the perceptual capability of the model, thereby improving performance without increasing network complexity. This design emphasizes gradient information and detailed features in visible images. Experimental results on the public TNO dataset demonstrate that our method achieves superior visual quality and preserves the most abundant image information. Moreover, experiments on spacecraft images validate the robustness and applicability of our approach. Simultaneously, our method also provides significant technical support for the optical field.

关键词： Image quality Imaging techniques Infrared imaging Infrared sensors Optical fields Optical imaging

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Imp: Highly Capable Large Multimodal Models for Mobile Devices

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IEEE Transactions on Multimedia 2025年

作者： Shao, Zhenwei Yu, Zhou Yu, Jun Ouyang, Xuecheng Zheng, Lihao Gai, Zhenbiao Wang, Mingyang Kuang, Zhenzhong Ding, Jiajun Hangzhou Dianzi University Key Laboratory of Complex Systems Modeling and Simulation School of Computer Science Hangzhou310005 China Harbin Institute of Technology Shenzhen Department of Computer Science and Technology Shenzhen China Hangzhou Dianzi University HDU-ITMO Joint Institute Hangzhou310005 China

By harnessing the capabilities of large language models (LLMs), recent large multimodal models (LMMs) have shown remarkable versatility in open-world multimodal understanding. Nevertheless, they are usually parameter-heavy and computation-intensive, thus hindering their applicability in resource-constrained scenarios. To this end, several lightweight LMMs have been proposed successively to maximize the capabilities under constrained scale (e.g., 3B). Despite the encouraging results achieved by these methods, most of them only focus on one or two aspects of the design space, and the key design choices that influence model capability have not yet been thoroughly investigated. In this paper, we conduct a systematic study for lightweight LMMs from the aspects of model architecture, training strategy, and training data. Based on our findings, we obtain Imp - a family of highly capable LMMs at the 2B$\sim$4B scales. Notably, our Imp-3B model steadily outperforms all the existing lightweight LMMs of similar size, and even surpasses the state-of-the-art LMMs at the 13B scale. With low-bit quantization and resolution reduction techniques, our Imp model can be deployed on a Qualcomm Snapdragon 8Gen3 mobile chip with a high inference speed of about 13 tokens/s. © 2025 IEEE.

关键词： Visual languages

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Design of large ring-column antenna satellite attitude-orbit integrated füll propulsion system

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Zhendong yu Chongji/Journal of Vibration and Shock 2025年第11期44卷 1-11页

作者： Wang, Shijie Sun, Minzhe Gao, Feng Ji, Yi Sun, Guanghui Dong, Fuxiang School of Astronautics Harbin Institute of Technology Harbin150001 China Frontier Science Center of Space Environment and Interaction of Matters Harbin150001 China State Key Lab for Modeling and Simulation of Complex Systems Harbin150001 China General Department of Communication and Navigation Satellite China Academy of Space Technology Beijing100094 China

As a key space structure in geostationary orbit, 100-meter level large ring-column antenna satellite is tasked with providing high-speed information transmission and stable communication Service in this orbit. This requires satellites having precise orbit maintenance and attitude control capabilities. Due to such satellites typically having larger masses and special structural designs, here, the high-precision orbit prediction algorithm was used to finely model and analyze effects of key space environmental factors of solar pressure, non-spherical perturbations and 3-body gravity on space Operation of such spacecrafts. Furthermore, referring to the design concept of formation-flying gravity field measurement satellites, a distributed füll thrust control strategy based on thruster layout optimization for such spacecrafts was proposed. Then, an improved explicit model predictive control algorithm was proposed based on Laguerre function to convert device capability limitations and Performance requirements into input-output constraints, combine multi-parameter programming, and realize attitude-orbit integrated control of such satellites. The simulation results showed that during stable Operation, position maintenance errors of such satellites can be controlled within a meter-level ränge, and attitude angle errors are better than 0. 03°;the computational efficiency of the proposed control algorithm is significantly higher than that of the Standard model predictive control algorithm and Laguerre function-based model predictive control algorithm;the hardware memory occupied is much lower than that of the explicit model predictive control *** theoretical analysis and numerical verification, it was shown that this study can provide an effective solving scheme for füll thruster integrated control of large ring-column antenna satellites in oomplex space environment using onboard Computers with limited Computing power. © 2025 Chinese Vibration Engineering Society.

关键词： Geostationary satellites

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Mask-guided Multi-scale Spatial-Spectral Transformer for Snapshot Compressive Imaging

Mask-guided Multi-scale Spatial-Spectral Transformer for Sna...

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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Heyuan Yin Jingxiang Yang Jia Liu Liang Xiao School of Computer Science and Engineering Nanjing University of Science and Technology Nanjing China Key Laboratory of Analysis of Mathematical Theory and Modeling of Complex Systems The Ministry of Industry and Information Technology China

ISBN: (数字)9798350368741

ISBN: (纸本)9798350368758

Effectively reconstructing 3D hyperspectral images (HSIs) from 2D measurements presents a significant challenge in Coded Aperture Snapshot Spectral Imaging (CASSI) systems. While recent transformers exhibit potential in HSI reconstruction, they often suffer from inadequate exploration of multi-scale spatial-spectral self-similarity, leading to mean effects and information loss. Additionally, these methods struggle with insufficient modeling of the degradation inherent in the compressive imaging process. To address these issues, we propose a novel Mask-guided Multi-scale Spatial-Spectral Transformer (MMSST). Specifically, we introduce a Degradation Aware Mask Attention (DAMA) module to incorporate degradation information of the compressive imaging process. Furthermore, MMSST leverages Local-Regional SpAtial attention (LRSA) and Global-Regional SpEctral attention (GRSE) to effectively exploit multi-scale self-similarity across spatial and spectral dimensions. Extensive experimental results demonstrate the effectiveness of our MMSST.

关键词： Degradation Three-dimensional displays Computational modeling Imaging Transformer cores Signal processing Transformers Speech processing Image reconstruction Hyperspectral imaging

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Enhancing realism in LiDAR scene generation with CSPA-DFN and linear cross-attention via Diffusion Transformer model

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Neural networks : the official journal of the International Neural Network Society 2025年 189卷 107503页

作者： Shaoxun Ye Xiaoguang Di Ming Liao Ximing Li Control and Simulation Center Harbin Institute of Technology Harbin 150080 China National Key Laboratory of Modeling and Simulation for Complex Systems Harbin 150080 China. National Key Laboratory of Modeling and Simulation for Complex Systems Harbin 150080 China. Electronic address: dixiaoguang@***.

Point cloud diffusion models have found extensive applications in autonomous driving and robotics. However, there is still a big gap between their generated LiDAR scene samples and real-world data in terms of visual quality. This discrepancy primarily arises from the loss of detailed information during the decoding process from latent space and the lack of guidance from global 3D structural information in the point cloud generation process, leading to distortions and artifacts in LiDAR scene samples. In this paper, we propose a novel LiDAR Diffusion Transformer Model that integrates Channel-Spatial Parallel Attention and Dilation Fusion Network (CSPA-DFN) with a linear cross-attention post-processing module to refine the generated LiDAR scene samples. Specifically, CSPA-DFN is designed to simultaneously emphasize detailed features across different channels and spatial locations in parallel, leveraging multi-scale dilated convolutions and channel grouping to preserve and enhance these detailed features. In order to provide global 3D structural information and balance performance and efficiency, we design a post-processing module that fuses voxelized features and range images using a linear ReLU cross-attention mechanism. Our approach is evaluated on the unconditional generation task using the KITTI-360 and nuScenes datasets, achieving the state-of-the-art results in LiDAR scene's generation quality. Furthermore, by incorporating semantic labels and camera views into the latent space, in addition to enhancing the model's semantic understanding capability for LiDAR scenes, our method also demonstrates additional performance improvements compared to previous works in terms of LiDAR scene's visual quality. The code implementation has been released on https://***/HITysx/LiDAR-Scene-Generation.

关键词： Channel-Spatial Parallel Attention Diffusion Transformer LiDAR scene generation Linear ReLU cross-attention

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Some new Liouville type theorems for 3D steady tropical climate model

arXiv

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arXiv 2025年

作者： Fang, Yan Zhang, Zhibing School of Mathematics and Physics Anqing Normal University Anqing246133 China School of Mathematics and Physics Key Laboratory of Modeling Simulation and Control of Complex Ecosystem in Dabie Mountains of Anhui Higher Education Institutes Anqing Normal University Anqing246133 China

In this paper, we study the Liouville type theorems for the stationary tropical climate model in three dimension. With the help of the delicate estimates of several integrals and an iteration argument, we establish Liouville type theorems under seventeen different assumptions. As a consequence, we show that a smooth solution is trivial provided that they belong to some Lebesgue spaces or satisfy some decay conditions at infinity. Our results extend and improve the recent work of Cho-In-Yang (2024 Appl. Math. Lett. 153 109039).MSC Codes 35B53, 35Q35, 35A02 © 2025, CC BY.

关键词： Climate models

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