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Novel algorithm for communication signal blind separation-EASIBSA algorithm

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Wuhan Ligong Daxue Xuebao/Journal of Wuhan University of Technology 2008年第1期30卷 91-94页

作者： Fu, Wei-Hong Yang, Xiao-Niu Liu, Nai-An Zeng, Xing-Wen State Key Lab. of Integrated Service Networks Xidian University Xi'an 710071 China National Laboratory of Information Control Technology for Communication System Jiangnan Electronic Communications Research Institute Jiaxing 314033 China

Aim at the problem of the communication signal blind source separation, a novel blind separation algorithm based on step size adaptation (EASIBSA) to increase the convergence rate of the separation algorithm was present by using the idea of parameter adaptation optimization, which was based on Equivariant Adaptive Separation via Independent (EASI) algorithm. This algorithm related the learning rate with the object function and adapted it by using the stochastic gradient method, which avoided the selection of optimum learning rate and speed up the convergence rate. Simulation results showed that improved algorithm could increase the convergence rate of separation algorithm by two times without affecting the separation capability.

关键词： Blind source separation Convergence rate Digital communication Parameter adaptation

青藏高原高寒草地植物的群落性状和功能在降水梯度上调控了生物量的分配权衡

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Journal of Plant Ecology 2023年第5期16卷 44-57页

作者： Le Sun Jian Sun Jun-Xi Wu Zi-Yin Du You-Jun Chen Yi Wang Miao Liu Wen-Cheng Li Er-Yuan Liang Key Laboratory of Tibetan Plateau Earth System Environment and ResourcesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Key Laboratory of Ecosystem Network Observation and Modelling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 1oo1o1China School of Geographical Sciences China West Normal UniversityNanchong 637002China Institute of the Qinghai-Tibetan Plateau Southwest Minzu UniversityChengdu 610500China School of Life Sciences and School of Ecology State Key Lab of Biological ControlSun Yat-sen UniversityGuangzhou 510275China College of Grassland Science and Technology China Agricultural UniversityBeijing 100193China

了解在不同生态系统中植物生物量分配的调控机制是阐明植物适应性策略的重要理论基础。目前,虽然生境条件对植物生物量分配的影响已被广泛研究,但对植物群落性状和功能(plant community traits and functions,PCTF)如何调控生物量分配,... 详细信息

了解在不同生态系统中植物生物量分配的调控机制是阐明植物适应性策略的重要理论基础。目前,虽然生境条件对植物生物量分配的影响已被广泛研究,但对植物群落性状和功能(plant community traits and functions,PCTF)如何调控生物量分配,特别是在高寒草地生态系统中的研究却较少。本研究计算了在群落水平上的5种叶片功能性状的群落加权平均值(community-weighted means,CWM),并利用相关分析、方差分解分析和结构方程模型探讨了PCTF与生物量权衡之间的关系。研究结果发现,高寒草甸(alpine meadow,AM)和高寒草原(alpine steppe,AS)的权衡值都大于零,但两者存在显著差异,AM的权衡值(0.203)明显高于AS(0.088)。此外,决定AS生物量分配的关键因素是物种丰富度(0.69)和叶片干物质含量(CWM_(LDMC),0.42),而在AM中,关键因素是叶片干物质含量(CWM_(LDMC),0.48)和叶片碳含量(CWM_(LC)-0.45)。值得注意的是,无论AS中的CWM_(LDMC)和物种丰富度,还是AM中的CWM_(LDMC)和CWM_(LC)都主要受气候因素中的降水调节。总而言之,降水往往通过对PCTF的影响来调控高寒草地的生物量分配,因此强调了PCTF在调节降水梯度上植物生物量分配策略的重要性。

关键词：群落加权平均权衡生物量分配植物群落性状和功能高寒草地青藏高原

Adaptive control of unmanned surface vessels matching an optimized reference model

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Adaptive control of unmanned surface vessels matching an opt...

IEEE International Conference on Robotics and Biomimetics

作者： Chenguang Yang Rongxin Cui Zhijun Li Sanjay Sharma Xingang Zhao Center for Robotics and Neural Systems Plymouth University Ply-mouth UK The MOE Key Lab of Autonomous System and Network Control South China University of Technology Guangzhou China School of Marine Science and Technology Northwestern Polytechnical University Xi'an China School of Marine Science and Engineering University of Plymouth Plymouth UK Shenyang Institute of Automation Chinese Academy of Sciences Shenyang China

ISBN: (纸本)9781479973989

In this paper, adaptive control of unmanned marine surface vessel has been investigated in the presence of uncertain dynamics as well as external disturbance. Variable structure technique has been utilized in the control design to make the dynamic response and desired motion tracking as quickly as possible. In practice, usually the desired trajectories are given as step points, such that direct immediate tracking would cause large acceleration and huge control effort, while the latter may be out of the actuators' limitation. Therefore, a reference model approach is employed, such that instead of direct tracking of the desired set point, the control objective becomes to shape the closed-loop dynamics to match a reference model. The reference model is built using optimization technique which tries to minimizes both tracking error and motion acceleration, and subsequently control effort. The smooth tracking is thus guaranteed in an optimal manner.

关键词： Tracking Acceleration Trajectory Adaptation models Performance analysis Mathematical model Dynamics

The strength of structural diversity in online social networks

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arXiv 2019年

作者： Zhang, Yafei Wang, Lin Zhu, Jonathan J.H. Wang, Xiaofan Pentland, Alex Department of Automation Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai 200240 China Department of Media and Communication School of Data Science City University of Hong Kong Hong Kong Hong Kong Department of Automation Shanghai University Shanghai 200444 China Media Lab Massachusetts Institute of Technology CambridgeMA02139 United States

Understanding the way individuals are interconnected in social networks is of prime significance to predict their collective outcomes. Leveraging a large-scale dataset from a knowledge-sharing website, this paper presents an exploratory investigation of the way to depict structural diversity in directed networks and how it can be utilized to predict one’s online social reputation. To capture the structural diversity of an individual, we first consider the number of weakly and strongly connected components in one’s contact neighborhood and further take the coexposure network of social neighbors into consideration. We show empirical evidence that the structural diversity of an individual is able to provide valuable insights to predict personal online social reputation, and the inclusion of coexposure network provides an additional ingredient to achieve that goal. After synthetically controlling several possible confounding factors through matching experiments, structural diversity still plays a nonnegligible role in the prediction of personal online social reputation. Our work constitutes one of the first attempts to empirically study structural diversity in directed networks and has practical implications for a range of domains, such as social influence and collective intelligence studies. Copyright © 2019, The Authors. All rights reserved.

关键词： Social networking (online)

Physical-layer key distribution using synchronous complex dynamics of DBR semiconductor lasers

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arXiv 2023年

作者： Wang, Anbang Du, Yicheng Li, Qingtian Wang, Longsheng Jia, Zhiwei Qin, Yuwen Wang, Yuncai Institute of Advanced Photonics Technology School of Information Engineering Guangdong University of Technology Guangzhou51006 China Key Laboratory of Photonic Technology for Integrated Sensing and Communication Ministry of Education of China Guangdong University of Technology Guangzhou51006 China Guangdong Provincial Key Laboratory of Information Photonics Technology Guangdong University of Technology Guangzhou51006 China Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan030024 China College of Optoelectronics Taiyuan University of Technology Taiyuan030024 China

Common-signal-induced synchronization of semiconductor lasers with optical feedback inspired a promising physical key distribution with information-theoretic security and potential in high rate. A significant challenge is the requirement to shorten the synchronization recovery time for increasing key rate without sacrificing operation parameter space for security. Here, open-loop synchronization of wavelength-tunable multi-section distributed Bragg reflector (DBR) lasers is proposed as a solution for physical-layer key distribution. Experiments show that the synchronization is sensitive to two operation parameters, i.e., currents of grating section and phase section. Furthermore, fast wavelength-shift keying synchronization can be achieved by direct modulation on one of the two currents. The synchronization recovery time is shortened by one order of magnitude compared to close-loop synchronization. An experimental implementation is demonstrated with a final key rate of 5.98 Mbit/s over 160 km optical fiber distance. It is thus believed that fast-tunable multi-section semiconductor lasers opens a new avenue of high-rate physical-layer key distribution using laser synchronization. Copyright © 2023, The Authors. All rights reserved.

关键词： Synchronization

Seismic Interpolation Transformer for Consecutively Missing Data: A Case Study in DAS-VSP Data

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arXiv 2024年

作者： Cheng, Ming Lin, Jun Dong, Xintong Lu, Shaoping Zhong, Tie College of Instrumentation and Electrical Engineering Jilin University Jilin Changchun130026 China School of Earth Sciences and Engineering Sun Yat-Sen University Guangdong Guangzhou510275 China Guangdong Zhuhai519000 China Guangdong Provincial Key Lab of Geodynamics and Geohazards Sun Yat-sen University Guangdong Guangzhou510275 China Key Laboratory of Modern Power System Simulation and Control and Renewable Energy Technology Ministry of Education Jilin132012 China Department of Communication Engineering College of Electric Engineering Northeast Electric Power University Jilin132012 China

Distributed optical fiber acoustic sensing (DAS) is a rapidly-developed seismic acquisition technology with advantages of low cost, high resolution, high sensitivity, and small interval, etc. Nonetheless, consecutively missing cases often appear in real seismic data acquired by DAS system due to some factors, including optical fiber damage and inferior coupling between cable and well. Recently, some deep-learning seismic interpolation methods based on convolutional neural network (CNN) have shown impressive performance in regular and random missing cases but still remain the consecutively missing case as a challenging task. The main reason is that the weight sharing makes it difficult for CNN to capture enough comprehensive features. In this paper, we propose a transformer-based interpolation method, called seismic interpolation transformer (SIT), to deal with the consecutively missing case. This proposed SIT is an encoder-decoder structure connected by some U-shaped swin-transformer blocks. In encoder and decoder part, the multi-head self-attention (MSA) mechanism is used to capture global features which is essential for the reconstruction of consecutively missing traces. The U-shaped swin-transformer blocks are utilized to perform feature extraction operations on feature maps with different resolutions. Moreover, we combine the loss based on structural similarity index (SSIM) and L1 norm to propose a novel loss function for SIT. In experiments, this proposed SIT outperforms U-Net and swin-transformer. Moreover, ablation studies also demonstrate the advantages of new network architecture and loss function. Copyright © 2024, The Authors. All rights reserved.

关键词： Optical fibers

Adaptively secure key-policy ABE scheme with fast decryption

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Tongxin Xuebao/Journal on communications 2014年 35卷 26-32页

作者： Li, Qi Ma, Jian-Feng Xiong, Jin-Bo Liu, Xi-Meng School of Computer Science and Technology Xidian University Xi'an710071 China Shaanxi Key Laboratory of Network and System Security Xidian University Xi'an710071 China Science and Technology on Communication Information Security Control Laboratory Jiaxing314033 China Faculty of Software Fujian Normal University Fuzhou350108 China School of Telecommunication Engineering Xidian University Xi'an710071 China

In the existing adaptively secure ABE (attribute-based encryption) schemes, the decryption cost goes linearly with the number of attributes that are used in decryption. An adaptively secure key-policy ABE (FKP-ABE) scheme with fast decryption is proposed, where constant size of computation overhead is implemented in decryption. This scheme is constructed on composite order bilinear groups and supports any monotonic access structure that can be expressed by LSSS (linear secret sharing schemes). The proposed scheme is proved to be adaptively secure in the standard model. ©, 2014, Editorial Board of Journal on communications. All right reserved.

关键词： Cryptography

MAE-GAN: A Novel Strategy for Simultaneous Super-resolution Reconstruction and Denoising of Post-stack Seismic Profile

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arXiv 2024年

作者： Yu, Wenshuo Dong, Shiqi Lu, Shaoping Dong, Xintong The College of Instrumentation and Electrical Engineering Jilin University Jilin Changchun130026 China The Key Laboratory of Modern Power System Simulation and the Control and Renewable Energy Technology Ministry of Education Jilin Jilin City132012 China Department of Communication Engineering College of Electric Engineering Northeast Electric Power University Jilin Jilin City132012 China School of Earth Sciences and Engineering Sun Yat-Sen University Guangdong Guangzhou510275 China Guangdong Zhuhai519000 China Guangdong Provincial Key Lab of Geodynamics and Geohazards Sun Yat-Sen University Guangdong Guangzhou510275 China

Post-stack seismic profiles are images reflecting containing geological structures which provides a critical foundation for understanding the distribution of oil and gas resources. However, due to the limitations of seismic acquisition equipment and data collecting geometry, the post-stack profiles suffer from low resolution and strong noise issues, which severely affects subsequent seismic interpretation. To better enhance the spatial resolution and signal-to-noise ratio of post-seismic profiles, a multi-scale attention encoder-decoder network based on generative adversarial network (MAE-GAN) is proposed. This method improves the resolution of post-stack profiles, and effectively suppresses noises and recovers weak signals as well. A multi-scale residual module is proposed to extract geological features under different receptive fields. At the same time, an attention module is designed to further guide the network to focus on important feature information. Additionally, to better recover the global and local information of post-stack profiles, an adversarial network based on a Markov discriminator is proposed. Finally, by introducing an edge information preservation loss function, the conventional loss function of the Generative Adversarial network is improved, which enables better recovery of the edge information of the original post-stack profiles. Experimental results on simulated and field post-stack profiles demonstrate that the proposed MAE-GAN method outperforms two advanced convolutional neural network-based methods in noise suppression and weak signal recovery. Furthermore, the profiles reconstructed by the MAE-GAN method preserve more geological structures. Copyright © 2024, The Authors. All rights reserved.

关键词： Generative adversarial networks

Multiple residual dense networks for reconfigurable intelligent surfaces cascaded channel estimation

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arXiv 2021年

作者： Jin, Yu Zhang, Jiayi Huang, Chongwen Yang, Liang Xiao, Huahua Ai, Bo Wang, Zhiqin The School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China The Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University Beijing100044 China Zhejiang Provincial Key Lab of Information Processing Communication and Networking Zhejiang University Hangzhou310007 China College of Computer Science and Electronic Engineering Hunan University Changsha410082 China ZTE Corporation State Key Laboratory of Mobile Network Mobile Multimedia Technology Shenzhen518057 China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing100044 China Henan Joint International Research Laboratory of Intelligent Networking and Data Analysis Zhengzhou University Zhengzhou450001 China Research Center of Networks and Communications Peng Cheng Laboratory Shenzhen518055 China China Academy of Information and Communications Technology Beijing100191 China

Reconfigurable intelligent surface (RIS) constitutes an essential and promising paradigm that relies programmable wireless environment and provides capability for space-intensive communications, due to the use of low-cost massive reflecting elements over the entire surfaces of man-made structures. However, accurate channel estimation is a fundamental technical prerequisite to achieve the huge performance gains from RIS. By leveraging the low rank structure of RIS channels, three practical residual neural networks, named convolutional blind denoising network, convolutional denoising generative adversarial networks and multiple residual dense network, are proposed to obtain accurate channel state information, which can reflect the impact of different methods on the estimation performance. Simulation results reveal the evolution direction of these three methods and reveal their superior performance compared with existing benchmark schemes. Copyright © 2021, The Authors. All rights reserved.

关键词： Channel estimation