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Constrained geometry analysis to resolve 3-D deformations from three ground-based radars

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Journal of Systems Engineering and Electronics 2021年第6期32卷 1263-1269页

作者： DENG Yunkai Zhu Jiaxin TIAN Weiming hu Cheng YANG Wenyu Radar Research Lab School of Information and ElectronicsBeijing Institute of TechnologyBeijing 100081China Key Labo-ratory of Electronic and Information Technology in Satellite Navigation Ministry of EducationBeijing Institute of TechnologyBeijing 100081China Chongqing Key Laboratory of Geological Environment Monitoring and Disaster Early-warning in Three Gorges Reservoir Area Chongqing Three Gorges UniversityChongqing 404000China Advanced Technology Research Insti-tute Beijing Institute of TechnologyJi’nan 250300China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

When multiple ground-based radars(GB-rads)are utilized together to resolve three-dimensional(3-D)deformations,the resolving accuracy is related with the measurement geometry constructed by these *** paper focuses on constrained geometry analysis to resolve 3-D deformations from three *** geometric dilution of precision(GDOP)is utilized to evaluate 3-D deformation accuracy of a single target,and its theoretical equation is derived by building a simplified 3-D coordinate *** for a 3-D scene,its optimal accuracy problem is converted into determining the minimum value of an objective function with a boundary *** genetic algorithm is utilized to solve this constrained optimization *** simulations are made to validate the correctness of the theoretical analysis results.

关键词： three-dimensional(3-D)deformation ground-based radar(GB-rad) constrained geometry geometric dilution of precision(GDOP) accuracy evaluation

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智慧学习环境中的创造力培养实证研究

中国电化教育 2017年第6期 11-16页

作者：胡小勇朱龙华南师范大学教育信息技术学院广东广州510631

信息时代,学习环境愈加智慧化。基于智慧学习环境,培养具有创造力的学习者也正逐渐受到重视。该文在系统梳理国内外研究基础之上,深入分析了智慧学习环境对于培养学生创造力的支持作用,并以提升学生创造力为出发点,借鉴创造性认知过程... 详细信息

信息时代,学习环境愈加智慧化。基于智慧学习环境,培养具有创造力的学习者也正逐渐受到重视。该文在系统梳理国内外研究基础之上,深入分析了智慧学习环境对于培养学生创造力的支持作用,并以提升学生创造力为出发点,借鉴创造性认知过程四阶段的观点,构建了基于智慧学习环境的创造力培养模式。该研究进一步采用单组前后测时间序列准实验研究,通过三轮实验从创造力流畅性、灵活性、独特性三个方面对创造力培养模式效果进行了测量,并结合访谈了解学生对应用该模式的态度。数据和访谈分析表明,该模式在提升学生创造力方面具有较显著的效果。

关键词：智慧学习环境创造力模式实证

A Naturalness-Preserved Low-Light Enhancement Algorithm for Intelligent Analysis

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Chinese Journal of Electronics 2019年第2期28卷 316-324页

作者： ZhuO Li hu Xiaochen LI Jiafeng ZHANG Jing LI Xiaoguang Signal & Information Processing Laboratory Beijing University of Technology Collaborative Innovation Center of Electric Vehicles

Images/videos captured in low-light conditions often present low luminance and *** the existing low-light enhancement algorithms can improve the subjective perception, color distortion and over-enhancement are extremely obvious, which will disturb the subsequent intelligent analysis. Therefore,a naturalness-preserved low-light enhancement algorithm for intelligent analysis is proposed in this paper. An enhancement model is established in RGB color *** of ColorChecker color chart are captured under a series of light conditions. To preserve the naturalness,the factors of the proposed enhancement model are estimated by the images captured in practical illumination environment. Experimental results demonstrate that the proposed algorithm can produce natural enhanced results and improve the performance of vehicle license plate localization and skin color detection compared to the existing algorithms. Furthermore, the proposed algorithm can process the 720p videos at the speed of 28.3 fps on average.

关键词： Low-light enhancement Intelligent analysis Naturalness-preserved Vehicle license plate localizations Skin color detection

Unsupervised Multi-Expert Learning Model for Underwater Image Enhancement

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 708-722页

作者： Hongmin Liu Qi Zhang Yufan hu hui Zeng Bin Fan the School of Intelligence Science and Technology and the Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China the School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China IEEE

Underwater image enhancement aims to restore a clean appearance and thus improves the quality of underwater degraded *** methods feed the whole image directly into the model for ***,they ignored that the R,G and B channels of underwater degraded images present varied degrees of degradation,due to the selective absorption for the *** address this issue,we propose an unsupervised multi-expert learning model by considering the enhancement of each color ***,an unsupervised architecture based on generative adversarial network is employed to alleviate the need for paired underwater *** on this,we design a generator,including a multi-expert encoder,a feature fusion module and a feature fusion-guided decoder,to generate the clear underwater ***,a multi-expert discriminator is proposed to verify the authenticity of the R,G and B channels,*** addition,content perceptual loss and edge loss are introduced into the loss function to further improve the content and details of the enhanced *** experiments on public datasets demonstrate that our method achieves more pleasing results in vision *** metrics(PSNR,SSIM,UIQM and UCIQE) evaluated on our enhanced images have been improved obviously.

关键词： Multi-expert learning underwater image enhancement unsupervised learning

Privacy Preserving Algorithm for Spectrum Sensing in Cognitive Vehicle Networks

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Chinese Journal of Electronics 2024年第1期33卷 30-42页

作者： Hongning LI Tonghui hu Jiexiong CHEN Xiuqiang WU Qingqi PEI Guangzhou Institute of Technology Xidian University Guangzhou CEPREI Shaanxi Key Laboratory of Blockchain and Secure Computing

The scarcity of spectrum resources fails to meet the increasing throughput demands of vehicular networks. There is an urgent need to maximize the utilization of spectrum bands in mobile networks. To ascertain the availability of spectrum bands, users should engage in wireless channel sensing and collaboration. However, spectrum sensing data always involves users' privacy, such as their location. This paper first introduces sensing trajectory inference attack in cognitive vehicular networks and then proposes a data confusion-based privacy-preserving algorithm and a cryptonym array-based privacy-preserving aggregation scheme for spectrum sensing in cognitive vehicular networks. Unlike existing methods, the proposed schemes transmit confused data during the aggregation process. This deliberate obfuscation makes it almost impossible to infer users' location from the transmitted data. The analysis demonstrates the resilience of the proposed schemes against sensing trajectory inference attack.

关键词： Privacy data privacy Wireless sensor networks Authentication data aggregation Throughput Inference algorithms

ON THE NECESSARY AND SUFFICIENT CONDITIONS TO SOLVE A HEAT EQUATION WITH GENERAL ADDITIVE GAUSSIAN NOISE

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Acta Mathematica Scientia 2019年第3期39卷 669-690页

作者： Yaozhong hu Yanghui LIU Department of Mathematical and Statistical Sciences University of AlbertaEdmontonT6G 2G1Canada Department of Mathematics Purdue UniversityWest LafayetteIN 47907USA

In this note, we consider stochastic heat equation with general additive Gaussian noise. Our aim is to derive some necessary and sufficient conditions on the Gaussian noise in order to solve the corresponding heat equation. We investigate this problem invoking two differen t met hods, respectively, based on variance compu tations and on pat h-wise considerations in Besov spaces. We are going to see that, as anticipated, both approaches lead to the same necessary and sufficient condition on the noise. In addition, the path-wise approach brings out regularity results for the solution.

关键词： Stochastic heat equation general Gaussian noise L^(2) solution sufficient and necessary condition Wong-Zakai approximation pathwise solution Holder continuity Besov space

Organic Brønsted Acid-Catalyzed Stereoselective Cationic RAFT Polymerization:The Effect of RAFT Agents

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Chinese Journal of Polymer Science 2024年第6期42卷 711-717页

作者： Zheng-Yi Zhang Zan Yang Yun Liao Sai-hu Liao Key Laboratory of Molecule Synthesis and Function Discovery(Fujian Province University) College of ChemistryFuzhou UniversityFuzhou350108China State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China Beijing National Laboratory for Molecular Sciences Beijing100190China

The tacticity of vinyl polymers is a key factor affecting the properties of ***,organic Brønsted acids have been demonstrated as effective catalysts for the development of highly stereoselective cationic reversible addition-fragmentation chain transfer(RAFT)polymerizations of vinyl ethers,in which the use of RAFT agents could allow the control the molecular weight and tacticity of polymer products ***,the effect of RAFT agents on the tacticity-regulation remains elusive and lacks of *** this study,we synthesized four types of RAFT agents and evaluated their influence in the stereoselective cationic polymerization of isobutyl vinyl ether in the presence of PADI as a Brønsted acid catalyst,which unveils that the Z group of RAFT agents could not only affect the polydispersity of the products,but also exert a profound effect on the *** extensive screening of the RAFT agents,high stereoregularity(isotacticity,90%m)was obtained when using dithiocarbonate ester-type RAFT agents with a benzyloxy Z group.

关键词： Bronsted acid catalysis Stereoselective cationic polymerization RAFT polymerization Chain transfer agents Tacticity

Mechanical and thermal properties of RETaO4(RE=Yb,Lu,Sc)ceramics with monoclinic-prime phase

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Journal of Materials Science & Technology 2020年第17期52卷 20-28页

作者： Lin Chen Mingyu hu Jun Guo Xiaoyu Chong Jing Feng Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093People's Republic of China School of Engineering Brown UniversityProvidenceRl02912USA

As candidate thermal/environmental barrier coatings(T/EBCs),the structure characteristics and comprehensive properties of monoclinic-prime(m')RETaO4(RE=Yb,Lu,Sc)with excellent Al2O3/SiO2 chemical compatibility are *** thermal insulation protection will be provided by m'RETaO4 due to their low thermal conductivity(~1.6 Wm^-1 K^-1,900℃)and prominent thermal radiation resistance,which is much better than those of YSZ(~2.5 Wm^-1 K^-1,1000℃)and La-12 Zr2O7(~2.0 Wm^-1 K,900℃).The thermal expansion coefficients(TECs)are 3.0–8.0×10^-6 K^-1(200-1200℃),which is suitable for T/EBCs ***,absence of phase transition and extraordinary chemical compatibility with Al2O3/SiO2 up to 1500℃indicate the potential application *** documented governing mechanisms of m'RETaO4 properties will enable researchers to promote their application in the future investigation.

关键词： Ceramics Thermal/environmental barrier coatings Rare earth tantalates Mechanical property Thermal conductivity Chemical compatibility

Mechanisms of photochemical release of dissolved organic matter and iron from resuspended sediments

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Journal of Environmental Sciences 2021年第6期33卷 288-295页

作者： Bin hu Peifang Wang Tianli Bao Jin Qian Xun Wang Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education Hohai UniversityNanjing 210098China College of Environment Hohai UniversityNanjing 201198China

Photochemical reactions can alter the transformation of sedimentary organic matter into dissolved organic matter(DOM)and affect its ultimate fate in water *** the present study,the photorelease of DOM and Fe from resuspended lake sediments was investigated under different O_(2)and NO_(3)-concentration conditions to study the mechanisms of DOM and Fe *** amount of photoreleased Fe,which ranged from 0.22 to 0.70μmol/L,was significantly linearly correlated with the amount of photoreleased DOM.O_(2)and NO_(3)-could promote the photochemical release of DOM and Fe,especially during the initial 4 h *** general,the order of the photorelease rates of DOM and Fe under different conditions was as follows:NO_(3)-/aerobic>aerobic≈NO_(3)-/anaerobic>*** photorelease rates of DOM and Fe were higher for the initial 4 hr irradiation than these for the subsequent 8 hr *** photorelease of DOM and Fe is thought to proceed via direct photodissolution and indirect *** relative contributions of indirect processes(>60%)was much greater than that of direct photodissolution(<40%).The photoproduced H 2 O_(2)under aerobic and anaerobic conditions indicated that hydroxyl radicals(·OH)are involved in the photorelease of ***·OH scavengers,it was found that 38.7%,53.7%,and 77.6%of photoreleased DOM was attributed to·OH under anaerobic,aerobic,and NO_(3)-/aerobic conditions,*** findings provide insights for understanding the mechanisms and the important role of·OH in the DOM and Fe photorelease from resuspended sediments.

关键词： Dissolved organic matter Fe Photorelease Hydroxyl radical Resuspended sediments