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Computer Modeling in engineering & Sciences 2024年第5期139卷 1935-1960页

作者： Yu Cheng Yajun Huang Shuai Li Zhongbin Zhou Xiaohui Yuan Yanming Xu College of Architecture and Civil engineering Xinyang Normal UniversityXinyang464000China Henan Unsaturated Soil and Special Soil engineering Technology research center Xinyang Normal UniversityXinyang464000China College of Intelligent Construction Wuchang University of TechnologyWuhan430223China College of Civil engineering and Architecture Dalian UniversityDalian116622China Henan International Joint Laboratory of Structural Mechanics and Computational simulation School of Architecture and Civil EngineeringHuanghuai UniversityZhumadian463000China

A new approach for flexoelectricmaterial shape optimization is proposed in this *** this work,a proxymodel based on artificial neural network(ANN)is used to solve the parameter optimization and shape optimization *** improve the fitting ability of the neural network,we use the idea of pre-training to determine the structure of the neural network and combine different optimizers for *** isogeometric analysis-finite element method(IGA-FEM)is used to discretize the flexural theoretical formulas and obtain samples,which helps ANN to build a proxy model from the model shape to the target *** effectiveness of the proposed method is verified through two numerical examples of parameter optimization and one numerical example of shape optimization.

关键词： Shape optimization deep learning flexoelectric structure finite element method isogeometric

research on concrete structure defect repair based on three-dimensional printing

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Frontiers of Structural and Civil engineering 2024年第5期18卷 731-742页

作者： Yang GU Wei LI Xupeng YAO Guangjun LIU School of Mechanical engineering Tongji UniversityShanghai 201804China College of Civil engineering Tongji UniversityShanghai 200092China Shanghai engineering research center for Safety Intelligent Control of Building Machinery Shanghai 200032China

Quality assurance and maintenance play a crucial role in engineering construction,as they have a significant impact on project *** common issue in concrete structures is the presence of *** enhance the automation level of concrete defect repairs,this study proposes a computer vision-based robotic system,which is based on three-dimensional(3D)printing technology to repair *** system integrates multiple sensors such as light detection and ranging(LiDAR)and *** is utilized to model concrete pipelines and obtain geometric parameters regarding their ***,a convolutional neural network(CNN)is employed with a depth camera to locate defects in concrete ***,a method for coordinate transformation is presented to convert the obtained coordinates into executable ones for a robotic ***,the feasibility of this concrete defect repair method is validated through simulation and experiments.

关键词： concrete defect detection 3D printing deep learning point cloud data

Structural disruption of melanin-like polymers with boosted UV protection

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Science China Chemistry 2024年第5期67卷 1653-1663页

作者： Zhen Yang Xianheng Wang Wanjie Bai Zikun Zou Haoxing Wu Yiwen Li Department of Radiology Huaxi MR Research CenterFunctional and Molecular Imaging Key Laboratory of Sichuan ProvinceNational Clinical Research Center for GeriatricsWest China HospitalSichuan UniversityChengdu 610041China College of Polymer Science and engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

Manipulating the energy structure of materials represents an efficient way to regulate their light absorption behaviors. For example, constructing donor-acceptor(D-A) structures to increase the polarizability and reduce the energy bandgap of local molecules has been widely used in the field of organic photovoltaics with ordered structures. Remarkably, even in disordered and chaotic systems such as melanin-like polydopamine(PDA), visible and near-infrared light absorption can be significantly improved using this strategy. However, there has been a noticeable dearth of research on the ultraviolet(UV) light absorption regulation of bioinspired polymers with disordered and chaotic architectures by tailoring the D-A microstructures. In this study, a series of benzoheterocyclic molecules with strong electron-donating features screened by molecular simulation calculations were involved in disrupting the D-A structures within PDA. The destruction of D-A structures promoted the increase of the energy band gap and finally boosted the UV absorption of PDA. The resulting PDA nanoparticles with enhanced UV absorption were further employed to fabricate UV shielding composite films to protect the growth of plants from harmful UV radiation. This research may open up new avenues for structural disruption of bioinspired polymers for enhanced photoprotection applications.

关键词： melanin-like polymers polydopamine D-A structure UV absorption photoprotection

AstroPose:Astronaut pose estimation using a monocular camera during extravehicular activities

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Science China(Technological Sciences) 2024年第6期67卷 1933-1945页

作者： LIU ZiBin LI You WANG ChunHui LIU Liang GUAN BangLei SHANG Yang YU QiFeng College of Aerospace Science and engineering National University of Defense TechnologyChangsha410073China Key Laboratory of Human Factors engineering China Astronaut Research and Training CenterBeijing100094China

With the completion of the Chinese space station,an increasing number of extravehicular activities will be executed by astronauts,which is regarded as one of the most dangerous activities in human space *** guarantee the safety of astronauts and the successful accomplishment of missions,it is vital to determine the pose of astronauts during extravehicular *** article presents a monocular vision-based pose estimation method of astronauts during extravehicular activities,making full use of the available observation ***,the camera is calibrated using objects of known structures,such as the spacesuit backpack or the circular handrail outside the space ***,the pose estimation is performed utilizing the feature points on the *** proposed methods are validated both on synthetic and semi-physical simulation experiments,demonstrating the high precision of the camera calibration and pose *** further evaluate the performance of the methods in real-world scenarios,we utilize image sequences of Shenzhou-13 astronauts during extravehicular *** experiments validate that camera calibration and pose estimation can be accomplished solely with the existing observation resources,without requiring additional complicated *** motion parameters of astronauts lay the technological foundation for subsequent applications such as mechanical analysis,task planning,and ground training of astronauts.

关键词： monocular camera astronaut pose estimation camera calibration

Dual-assisted high-precision tracking technique for wideband multiplexed signals in new generation GNSS

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Satellite Navigation 2024年第1期5卷 52-73页

作者： Yunhan Qi Zheng Yao Mingquan Lu Department of Electronic engineering Tsinghua UniversityBeijing100084China Beijing National research center for Information Science and Technology Beijing100084China

With the evolution of Global Navigation Satellite System(GNSS),new generation GNSS signals have adopted the dual-frequency multiplexing modulation techniques,which jointly modulate multiple signals located on multiple sub-frequencies into a Wideband Multiplexed Signal(WMS).Although WMSs were proposed initially to reduce the complexity of satellite transmitters and improve the transmission efficiency of signals,their multi-component structures and wide root mean square bandwidths introduced by high-frequency subcarriers also provide the possibility to improve the GNSS ranging ***,this paper proposes a Dual-assisted Multi-component Tracking(DMT)technique,which can not only fully use high-frequency subcarriers in WMSs,but also effectively track carrier,subcarrier,and code by jointly utilizing all components in *** this paper,the tracking and ranging performances of DMT are comprehensively analyzed theoretically and by simulation and real *** results show that compared with existing WMS tracking methods,DMT can achieve tracking results with lower tracking jitters and ranging results with higher precision,providing a highly advantageous solution for new generation GNSS signal processing.

关键词： Wideband multiplexed signal Dual-assisted Multi-component High precision tracking

Automatic modeling algorithm of stochastic error for inertial sensors

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Control Theory and Technology 2024年第1期22卷 81-91页

作者： Luodi Zhao Long Zhao School of Automation Science and Electrical engineering Beihang UniversityBeijing100191China digital Navigation center Beihang UniversityBeijing100191China Science and Technology on Aircraft Control Laboratory Beihang UniversityBeijing100191China

This paper proposes an automatic algorithm to determine the properties of stochastic processes and their parameters for inertial error. The proposed approach is based on a recently developed method called the generalized method of wavelet moments (GMWM), whose estimator was proven to be consistent and asymptotically normally distributed. This algorithm is suitable mainly (but not only) for the combination of several stochastic processes, where the model identification and parameter estimation are quite difficult for the traditional methods, such as the Allan variance and the power spectral density analysis. This algorithm further explores the complete stochastic error models and the candidate model ranking criterion to realize automatic model identification and determination. The best model is selected by making the trade-off between the model accuracy and the model complexity. The validation of this approach is verified by practical examples of model selection for MEMS-IMUs (micro-electro-mechanical system inertial measurement units) in varying dynamic conditions.

关键词： GMWM Stochastic process Inertial sensor Sensor calibration Error model Allan variance

An Improved JSO and Its Application in Spreader Optimization of Large Span Corridor Bridge

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Computer Modeling in engineering & Sciences 2024年第3期138卷 2357-2382页

作者： Shude Fu Xinye Wu Wenjie Wang Yixin Hu Zhengke Li Feng Jiang Fujian Key Laboratory of digital simulations for Coastal Civil engineering School of Architecture and Civil EngineeringXiamen UniversityXiamen361005China Xiamen Transportation Infrastructure Intelligent Management and Maintenance engineering Technology research center Xiamen361005China Fuzhou Company of China Communications Construction Co. Ltd.Fuzhou350005China

In this paper,given the shortcomings of jellyfish search algorithmwith low search ability in the early stage and easy to fall into local optimal solution,this paper introduces adaptive weight function and elite strategy,improving the global search scope in the early stage and the ability to refine the local development in the later *** the numerical study,the benchmark problem of dimensional optimization with a 10-bar truss structure and simultaneous dimensional shape optimization with a 15-bar truss structure is adopted,and the corresponding penalty method is used for constraint *** test results show that the improved jellyfish search algorithm can provide better truss sections as well as *** when the steel main truss of the large-span covered bridge is lifted,the site is limited and the large lifting equipment cannot enter the site,and the original structure does not meet the problem of stress concentration and large deformation of the bolt group,so the spreader is used to lift,and the improved jellyfish search algorithm is introduced into the design optimization of the *** results show that the improved jellyfish algorithm can efficiently and accurately find out the optimal shape and weight of the spreader,and throughMidas Civil simulation,the spreader used canmeet the requirements of weight and safety.

关键词： Truss optimization improved JSO size optimization shape optimization

A digital twin-enhanced collaborative maintenance paradigm for aero-engine fleet

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Frontiers of engineering Management 2024年第2期11卷 356-361页

作者： Jiawei REN Ying CHENG Yingfeng ZHANG Fei TAO School of Automation Science and Electrical engineering Beihang UniversityBeijing 100083China School of Mechanical engineering Northwestern Polytechnical UniversityXi’an 710072China digital Twin International research center International Research Institute for Multidisciplinary SciencesBeihang UniversityBeijing 100083China

Maintenance of aero-engine fleets is crucial for the efficiency,safety,and reliability of the aviation *** the increasing demand for air transportation,maintaining high-performing aero-engines has become *** maintenance,specifically targeting aero-engine fleets,involves the coordination of multiple tasks and resources to enhance management efficiency and reduce *** Twin(DT)technology provides essential technical support for the intelligent operation and maintenance of aero-engine *** maps physical object properties to the virtual world,creating high-fidelity,dynamic ***,DT-enhanced collaborative maintenance faces various challenges,including the construction of complex system-layer DT models,management of massive integrated DT data,and the development of fusion mechanisms and decision-making methods for DT data and *** these challenges will allow the aviation industry to optimize aero-engine fleet maintenance,ensuring safety,efficiency,and cost-effectiveness while meeting the growing demand for air transportation.

关键词： aero-engine fleet collaborative maintenance digital Twin(DT) complex system

Sparse convolutional model with semantic expression for waste electrical appliances recognition

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Science China(Technological Sciences) 2024年第9期67卷 2881-2893页

作者： HAN HongGui LIU YiMing LI FangYu DU YongPing Faculty of Information Technology Beijing University of TechnologyBeijing 100124China Beijing Key Laboratory of Computational Intelligence and Intelligent System Beijing 100124China engineering research center of digital Community Ministry of EducationBeijing 100124China Beijing Artificial Intelligence Institute and Beijing Laboratory for Intelligent Environmental Protection Beijing 100124China

Deep neural networks play an important role in the recognition of waste electrical appliances. However, deep neural network components still lack reliability in decision-making features. To address this problem, a sparse convolutional model with semantic expression(SCMSE) is proposed. First, a low-rank sparse semantic expression component, combining the benefits of residual networks and sparse representation, is adapted to enhance sparse feature extraction and semantic expression. Second, a reliable network architecture is obtained by iterating the optimal sparse solution, enhancing semantic expression. Finally, the results of visualization experiments on the waste electrical appliances dataset demonstrate that the proposed SCMSE can obtain excellent semantic performance.

关键词： sparse convolutional model deep neural network semantic expression visualization computer vision

Cinobufotalin prevents bone loss induced by ovariectomy in mice through the BMPs/SMAD and Wnt/β-catenin signaling pathways

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Animal Models and Experimental Medicine 2024年第3期7卷 208-221页

作者： Da-zhuang Lu Li-jun Zeng Yang Li Ran-li Gu Meng-long Hu Ping Zhang Peng Yu Xiao Zhang Zheng-wei Xie Hao Liu Yong-sheng Zhou Department of Prosthodontics Peking University School and Hospital of StomatologyBeijingChina National center of Stomatology BeijingChina National Clinical research center for Oral Diseases BeijingChina Beijing Key Laboratory of digital Stomatology BeijingChina Department of Cariology and Endodontology Peking University School and Hospital of StomatologyBeijingChina Peking University International Cancer Institute Peking University Health Science CenterPeking UniversityBeijingChina Central Laboratory Peking University School and Hospital of StomatologyBeijingChina National engineering research center of Oral Biomaterials and digital Medical Devices BeijingChina

Background:Osteoporosis is a chronic bone disease characterized by bone loss and decreased bone ***,current anti-resorptive drugs carry a risk of various *** deep learning-based efficacy prediction system(DLEPS)is a forecasting tool that can effectively compete in drug screening and prediction based on gene expression *** study aimed to explore the protective effect and potential mechanisms of cinobufotalin(CB),a traditional Chinese medicine(TCM),on bone ***:DLEPS was employed for screening anti-osteoporotic agents according to gene profile changes in primary ***-CT,histological and morphological analysis were applied for the bone protective detection of CB,and the osteogenic differentiation/function in human bone marrow mesenchymal stem cells(hBMMSCs)were also *** underlying mechanism was verified using qRT-PCR,Western blot(WB),immunofluorescence(IF),***:A safe concentration(0.25mg/kg in vivo,0.05μM in vitro)of CB could effectively preserve bone mass in estrogen deficiency-induced bone loss and promote osteogenic differentiation/function of *** BMPs/SMAD and Wnt/β-catenin signaling pathways participated in CB-induced osteogenic differentiation,further regulating the expression of osteogenesis-associated factors,and ultimately promoting ***:Our study demonstrated that CB could significantly reverse estrogen deficiency-induced bone loss,further promoting osteogenic differentiation/function of hBMMSCs,with BMPs/SMAD and Wnt/β-catenin signaling pathways involved.

关键词： BMPs/SMAD bone loss cinobufotalin hBMMSCs osteogenesis osteoporosis Wnt/β-catenin signaling pathways