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基于深度学习复杂环境的偏振成像技术研究进展(特邀)

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红外与激光工程 2024年第3期53卷 1-18页

作者：胡浩丰黄一钊朱震马千文翟京生李校博天津大学海洋科学与技术学院天津300072 天津大学精密仪器与光电子工程学院天津300072

偏振成像技术通过偏振信息的获取和解译,可以有效抑制复杂环境干扰,提升成像质量,增强目标感知能力,对于复杂环境下的光学成像探测具有独特优势。然而,在散射、低照度等复杂环境下,偏振图像退化机理呈现非线性特征,偏振信息解译方法复... 详细信息

偏振成像技术通过偏振信息的获取和解译,可以有效抑制复杂环境干扰,提升成像质量,增强目标感知能力,对于复杂环境下的光学成像探测具有独特优势。然而,在散射、低照度等复杂环境下,偏振图像退化机理呈现非线性特征,偏振信息解译方法复杂度高。深度学习方法具有强大的特征提取和学习能力,通过学习大规模数据隐藏的映射规律获得偏振信息的复原效果,特别适合偏振成像这种多维度、相互关联的复杂信号处理问题。文中基于偏振成像的基本原理以及复杂环境偏振成像技术的范式,针对散射和噪声这两类典型的成像环境,介绍了深度学习偏振成像技术的研究进展,同时阐述了深度学习赋能复杂环境偏振成像任务的优势,最后对该领域的未来发展方向作以展望。

关键词：偏振成像深度学习图像去散射图像去噪

基于深度神经网络的水下图像偏振信息复原方法

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光学学报 2024年第12期44卷 53-62页

作者：刘贺东韩宜霖李校博程振洲刘铁根翟京生胡浩丰天津大学精密仪器与光电子工程学院天津300072 天津大学海洋科学与技术学院天津300072

偏振度和偏振角等偏振信息能够反映目标的偏振特性,根据偏振态的差异可以辨别目标,因此偏振信息在水下探测与识别等领域有重要应用。传统的水下偏振成像方法能够对水下图像进行散射抑制并复原光强图像,但这些方法忽略了对偏振信息的复原... 详细信息

偏振度和偏振角等偏振信息能够反映目标的偏振特性,根据偏振态的差异可以辨别目标,因此偏振信息在水下探测与识别等领域有重要应用。传统的水下偏振成像方法能够对水下图像进行散射抑制并复原光强图像,但这些方法忽略了对偏振信息的复原,造成偏振信息的丢失。因此,提出基于通道注意力机制的水下图像偏振信息复原神经网络,以拓展水下偏振成像的功能,将偏振度和偏振角信息进行复原。同时设计了基于偏振参量的内容与风格损失函数,进一步提升偏振复原效果。实验结果表明,该网络可有效地抑制水下图像的散射光,同时能较好地恢复线性偏振度和偏振角信息。所提方法对浑浊水下偏振成像技术的进一步应用具有重要意义。

关键词：偏振成像水下成像偏振信息复原深度学习注意力机制

Efficient Computational Approach for Predicting the 3D Acoustic Radiation of the Elastic Structure in Pekeris Waveguides

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Journal of Ocean University of China 2022年第4期21卷 903-916页

作者： QIAN Zhiwen HE Yuanan SHANG Dejiang ZHAO Haihan zhai jingsheng School of Marine Science and Technology Tianjin UniversityTianjin 300072China Systems Engineering Research Institute Beijing 100036China College of Underwater Acoustics Engineering Harbin Engineering UniversityHarbin 150001China

Ocean boundaries present a significant effect on the vibroacoustic characteristics and sound propagation of an elastic structure in *** this study,an efficient finite element/wave superposition method(FE/WSM)for predicting the three-dimen-sional acoustic radiation from an arbitrary-shaped radiator in Pekeris waveguides with a lossy seabed is *** method is based on the FE method(FEM),WSM,and sound propagation ***,a near-field vibroacoustic model is established by the FEM to obtain vibration information on a radiator ***,the WSM based on the Helmholtz boundary integral is used to pre-dict the far-field acoustic radiation and ***,the rigorous image source method and complex normal mode are employed to obtain the near-and far-field Green’s function(GF),*** former,which is based on the spherical wave decomposition,is adopted to accurately solve the near-field source strength,and the far-field acoustic radiation is calculated by the latter and perturbation *** simulations of both models are compared to theoretical wavenumber integration ***,numerical experiments on elastic spherical and cylindrical shells in Pekeris waveguides are presented to validate the accuracy and efficiency of the proposed *** results show that the FE/WSM is adaptable to complex radiators and ocean-acoustic envi-ronments,and are easy to implement and computationally efficient in calculating the structural vibration,acoustic radiation,and sound propagation of arbitrarily shaped radiators in practical ocean environments.

关键词： elastic structure acoustic radiation Pekeris waveguide wave superposition method Green’s function image source method spherical wave decomposition

Sound speed profiles in high spatiotemporal resolution using multigrid three-dimensional variational method:a coastal experiment off northern Shandong Peninsula

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Journal of Oceanology and Limnology 2023年第1期41卷 57-71页

作者： Guangchao HOU jingsheng zhai Qi SHAO Yanling ZHAO Wei LI Guijun HAN Kangzhuang LIANG School of Marine Science and Technology Tianjin UniversityTianjin 300072China Tianjin Key Laboratory for Oceanic Meteorology Tianjin 300074China The PLA 31010 Units Beijing 100081China

It is essential to ac quire sound speed profiles(SSPs)in high-precision spatiotemporal resolution for undersea acoustic ***,conventional observation methods cannot obtain high-resolution ***,S SPs are complex and changeable in time and space,especially in coastal *** proposed a new space-time multigrid three-dimensional variational method with weak constraint term(referred to as STC-MG3DVar)to construct high-precision spatiotemporal resolution SSPs in coastal areas,in which sound velocity is defined as the analytical variable,and the Chen-Millero sound velocity empirical formula is introduced as a weak constraint term into the cost function of the *** spatiotemporal correlation of sound velocity observations is taken into account in the STC-MG3DVar method,and the multi-scale information of sound velocity observations from long waves to short waves can be successively *** weak constraint term can optimize sound velocity by the physical relationship between sound velocity and temperature-salinity to obtain more reasonable and accurate *** verify the accuracy of the STC-MG3DVar,SSPs observations and CTD observations(temperature observations,salinity observations)are obtained from field experiments in the northern coastal area of the Shandong *** average root mean square error(RMSE)of the STC-MG3DVar-constructed SSPs is 0.132 m/s,and the STC-MG3DVar method can improve the SSPs construction accuracy over the space-time multigrid 3DVar without weak constraint term(ST-MG3DVar)by 10.14%and over the spatial multigrid 3DVar with weak constraint term(SC-MG3DVar)by 44.19%.With the advantage of the constraint term and the spatiotemporal correlation information,the proposed STC-MG3DVar method works better than the ST-MG3DVar and the SCMG3DVar in constructing high-precision spatiotemporal re solution SSPs.

关键词： space-time multigrid 3DVar sound speed profiles temperature salinity spatiotemporal correlation multiscale

An operational radar current observing and data service platform in the East China Sea

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Acta Oceanologica Sinica 2016年第11期35卷 9-15页

作者： DENG Zeng'an ZHANG Anmin zhai jingsheng YU Ting WU Shuangquan ZHANG Xuefeng KANG Linchong ZHANG Yuming School of Marine Science and Technology Tianjin UniversityTianjin 300072China National Marine Data and Information Service State Oceanic AdministrationTianjin 300171China National Marine Environmental Monitoring Center State Oceanic AdministrationDalian 116023China

An ocean state monitor and analysis radar（OSMAR）, developed by Wuhan University in China, have been mounted at six stations along the coasts of East China Sea（ECS） to measure velocities（currents, waves and winds） at the sea surface. Radar-observed surface current is taken as an example to illustrate the operational high-frequency（HF） radar observing and data service platform（OP）, presenting an operational flow from data observing, transmitting, processing, visualizing, to end-user service. Three layers（systems）： radar observing system（ROS）, data service system（DSS） and visualization service system（VSS）, as well as the data flow within the platform are introduced. Surface velocities observed at stations are synthesized at the radar data receiving and preprocessing center of the ROS, and transmitted to the DSS, in which the data processing and quality control（QC） are conducted. Users are allowed to browse the processed data on the portal of the DSS, and access to those data files. The VSS aims to better show the data products by displaying the information on a visual globe. By utilizing the OP, the surface currents in East China Sea are monitored, and hourly and seasonal variabilities of them are investigated.

关键词： radar operational system currents data service visualization

ALTERNATING OPTIMIZATION METHOD FOR ISOGEOMETRIC TOPOLOGY OPTIMIZATION WITH STRESS CONSTRAINTS

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Journal of Computational Mathematics 2024年第1期42卷 134-155页

作者： Xiaoya zhai School of Mathematical Sciences University of Science and Technology of ChinaHefei 230071China

Topology optimization (TO) has developed rapidly recently. However, topology optimization with stress constraints still faces many challenges due to its highly non-linear properties which will cause inefficient computation, iterative oscillation, and convergence guarantee problems. At the same time, isogeometric analysis (IGA) is accepted by more and more researchers, and it has become one important tool in the field of topology optimization because of its high fidelity. In this paper, we focus on topology optimization with stress constraints based on isogeometric analysis to improve computation efficiency and stability. A new hybrid solver combining the alternating direction method of multipliers and the method of moving asymptotes (ADMM-MMA) is proposed to solve this problem. We first generate an initial feasible point by alternating direction method of multipliers (ADMM) in virtue of the rapid initial descent property. After that, we adopt the method of moving asymptotes (MMA) to get the final results. Several benchmark examples are used to verify the proposed method, and the results show its feasibility and effectiveness.

关键词： Isogeometric topology optimization Stress constraints The ADMM-MMA solver

DCVAE-adv:A Universal Adversarial Example Generation Method for White and Black Box Attacks

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Tsinghua Science and Technology 2024年第2期29卷 430-446页

作者： Lei Xu Junhai zhai College of Mathematics and Information Science Hebei UniversityBaoding 071002China

Deep neural network(DNN)has strong representation learning ability,but it is vulnerable and easy to be fooled by adversarial *** order to handle the vulnerability of DNN,many methods have been *** general idea of existing methods is to reduce the chance of DNN models being fooled by observing some designed adversarial examples,which are generated by adding perturbations to the original *** this paper,we propose a novel adversarial example generation method,called *** from the existing methods,DCVAE-adv constructs adversarial examples by mixing both explicit and implicit perturbations without using original ***,the proposed method can be applied to both white box and black box *** addition,in the inference stage,the adversarial examples can be generated without loading the original images into memory,which greatly reduces the memory *** compared DCVAE-adv with three most advanced adversarial attack algorithms:FGSM,AdvGAN,and AdvGAN++.The experimental results demonstrate that DCVAE-adv is superior to these state-of-the-art methods in terms of attack success rate and transfer ability for targeted *** code is available at https://***/xzforeverlove/DCVAE-adv.

关键词： deep neural network adversarial examples white box attack black box attack robustness

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多波束测量技术与海洋测绘工序的调整

武汉大学学报（信息科学版） 2007年第11期32卷 994-997页

作者：翟京生天津海洋测绘研究所天津市友谊路40号300061

总结了NS到H-Cell的科学涵义,同时结合海洋测量、数据库和产品化技术的相互影响,考察了目前的海图产品测绘的工序,按照水深测量与摄影测量技术的特点,提出了陆地与海洋NS、H-Cell的差异。设计了一个海洋测绘的调整工序,不仅提高了海图... 详细信息

总结了NS到H-Cell的科学涵义,同时结合海洋测量、数据库和产品化技术的相互影响,考察了目前的海图产品测绘的工序,按照水深测量与摄影测量技术的特点,提出了陆地与海洋NS、H-Cell的差异。设计了一个海洋测绘的调整工序,不仅提高了海图产品化的实时性,而且扩大了海洋测绘产品的多样性。

关键词：多波束水深测量摄影测量海图数据库航海表面 H-Cell 工序

Mechanism of microarc oxidation on AZ91D Mg alloy induced byβ-Mg_(17)Al_(12) phase

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 712-724页

作者： Dajun zhai Xiaoping Li Jun Shen College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg *** kinds of nano-particles(ZrO_(2)and TiO_(2))were designed to be added into the substrate of Mg alloy by friction stir processing(FSP).Then,Mg alloy sample designed with different precipitated morphology ofβ-Mg_(17)Al_(12)phase was treated by microarc oxidation(MAO)in Na_(3)PO_(4)/*** characteristics and performance of the MAO coating was analyzed using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),contact angle meter,and potentiodynamic *** was found that the coarseα-Mg grains in extruded AZ91D Mg alloy were refined by FSP,and theβ-Mg_(17)Al_(12)phase with reticular structure was broken and *** nano-ZrO_(2)particles were pinned at the grain boundary by FSP,which refined theα-Mg grain and promoted the precipitation ofβ-Mg_(17)Al_(12)phase in *** effectively inhibited the“cascade”phenomenon of microarcs,which induced the uniform distribution of discharge *** MAO coating on Zr-FSP sample had good wettability and corrosion ***,TiO_(2)particles were hardly detected in the coating on TiFSP sample.

关键词： AZ91D Mg alloy microarc oxidation friction stir processing ZrO_(2) TiO_(2) β-Mg_(17)Al_(12)