检索结果-内蒙古大学图书馆

Aero-structural design of joined-wing aircraft based on high-fidelity model

Chinese Journal of Aeronautics 2024年第4期37卷 363-377页

作者： Cheng HE Fengjiang ZHAN Luchuang MA Gang CHEN Jianying MA Unmanned Air Vehicle Research Institute Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Advanced Technology for Small and Medium-sized UAV Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China Aerospace System Engineering Shanghai Shanghai 201108China

The joined-wing configuration reduces induced drag and structural weight by connecting the rear wing to the front *** addition,the rear wing can replace the role of the horizontal tail of a conventional aircraft,thus eliminating the aerodynamic drag and weight associated with the horizontal *** particular shape creates a highly coupled relationship between aerodynamics and structure,which must be fully considered during the overall design process to enhance aircraft *** this research,an aero-structural design model of the joined-wing aircraft is constructed based on high-fidelity computational fluid dynamics and structural finite element *** model is able to obtain accurate aerodynamic loads for the non-planar wing and to simulate the statically indeterminate structure of the closed wing *** influence of the joined-wing shape parameters on the aerodynamic and structural disciplines,as well as the influence of geometric nonlinear characteristics,deformation constraints and buckling constraints on the structural weight are all taken into *** model is applied to complete the aero-structural design optimization of a high-altitude long-endurance joined-wing aircraft,and wind tunnel tests are *** test results verify the credibility of the design model proposed and the validity of the design environment.

关键词： Joined-wing configuration Aircraft design Aero-structural design Finite element Wind tunnel test

来源：评论

学校读者我要写书评

暂无评论

HCU-Net: An Efficient Fully Convolutional Neural Network for Thyroid Nodules Ultrasound Image Segmentation

HCU-Net: An Efficient Fully Convolutional Neural Network for...

引用

2024 IEEE International Conference on systems, Man, and Cybernetics, SMC 2024

作者： Ren, Mengxi Liu, Jun School of Computer Science and Technology Wuhan University of Science and Technology Wuhan China Wuhan University of Science and Technology Hubei Province Key Laboratory of Intelligent Information Processing and Real-Time Industrial System Wuhan China

ISBN: (纸本)9781665410205

Thyroid nodules, which can manifest as solitary or multiple growths, are among the most prevalent diseases with a high incidence rate. When examining thyroid nodules, ultrasound is typically the first step. Ultrasound image segmentation of thyroid nodules can assist physicians in diagnosis. However, the following three factors limit the development of thyroid nodule segmentation: (1) most of the existing studies optimize the segmentation of single nodules, and the incidence of multiple nodules is higher, so the segmentation of multiple nodules is also very important;(2) the ultrasound image of thyroid nodules is difficult to segment because of its low resolution and fuzzy boundary;(3) Due to the small data set of thyroid nodule ultrasound, in such a small dataset, attention mechanisms may be prone to overfitting, resulting in poorer generalization performance. Therefore, the attention-based model may not be suitable for the segmentation of thyroid nodules. Hence, we propose Hybrid Convolutional U-Net (HCU-Net), a simple and strong fully convolutional neural network for the segmentation of single or multiple thyroid nodules. HCU-Net incorporates a large receptive field to ensure accurate and stable segmentation. Specifically, we design Hybrid Branch Block to enhance the network's feature extraction capability for single or multiple nodules in ultrasound images by integrating multi-scale features. Furthermore, we add Enhanced ConvNeXt Blocks to the U-Net's final layer, enabling the extraction of global contextual information for segmentation performance. The Experimental results show that our proposed method can effectively improve these issues on two publicly available datasets. In addition, compared to attention-based models, our network is simpler and more suitable for small datasets like ultrasound images. © 2024 IEEE.

关键词： Ultrasonic imaging

来源：评论

学校读者我要写书评

暂无评论

An Improved YOLOv5s-Based Smoke Detection system for Outdoor Parking Lots

引用

Computers, Materials & Continua 2024年第8期80卷 3333-3349页

作者： Ruobing Zuo Xiaohan Huang Xuguo Jiao Zhenyong Zhang State Key Laboratory of Public Big Data College of Computer Science and TechnologyGuizhou UniversityGuiyang550025China School of Information and Control Engineering Qingdao University of TechnologyQingdao266520China State Key Laboratory of Industrial Control Technology College of Control Science and EngineeringZhejiang UniversityHangzhou310027China Key Laboratory of Computing Power Network and Information Security Ministry of EducationQilu University of Technology(Shandong Academy of Sciences)Jinan250353China Text Computing&Cognitive Intelligence Engineering Research Center of National Education Ministry Guizhou UniversityGuiyang550025China

In the rapidly evolving urban landscape,outdoor parking lots have become an indispensable part of the city’s transportation *** growth of parking lots has raised the likelihood of spontaneous vehicle combus-tion,a significant safety hazard,making smoke detection an essential preventative ***,the complex environment of outdoor parking lots presents additional challenges for smoke detection,which necessitates the development of more advanced and reliable smoke detection *** paper addresses this concern and presents a novel smoke detection technique designed for the demanding environment of outdoor parking ***,we develop a novel dataset to fill the gap,as there is a lack of publicly available *** dataset encompasses a wide range of smoke and fire scenarios,enhanced with data augmentation to ensure robustness against diverse outdoor ***,we utilize an optimized YOLOv5s model,integrated with the Squeeze-and-Excitation Network(SENet)attention mechanism,to significantly improve detection accuracy while maintaining real-time processing ***,this paper implements an outdoor smoke detection system that is capable of accurately localizing and alerting in real time,enhancing the effectiveness and reliability of emergency *** show that the system has a high accuracy in terms of detecting smoke incidents in outdoor scenarios.

关键词： YOLOv5s smoke detection deep learning SENet

来源：评论

学校读者我要写书评

暂无评论

Turbulent heat fluxes in the North Water Polynya and ice estimated based on ASRv2 data and their impact on cloud

引用

Advances in Climate Change Research 2024年第5期15卷 798-814页

作者： Hai-Yi REN Mohammed SHOKR Tian-Yu ZHANG Zhi-Lun ZHANG Feng-Ming HUI Xiao CHENG School of Geospatial Engineering and Science Sun Yat-sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Key Laboraory of Comprehensive Obseration of Polar Environment(Sun Yat-en University)Minisry of Education Zhuhai 519082 China State Key Laboratory of Remote Sensing Science Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China State Key Laboratory of Space-Ground Integrated Information Technology Beijing Institute of Satllite Information Engineering Beijing 100086China Science and Technology Branch Environment CanadaToronto Ontario M3H5T4Canada

The presence or absence of sea ice introduces a substantial perturbation to surface-atmosphere energy *** the effect of varying sea ice cover on surface-atmosphere interactions is an important consideration for understanding the Arctic climate *** recurring North Water Polynya(NOW)serves as a natural laboratory for isolating cloud responses to a rapid,near-step perturbation in sea *** this study,we employed high-resolution Arctic system Reanalysis version 2(ASRv2)data to estimate turbulent heat fluxes over the NOW and nearby sea ice(NSI)area between 2005/2006 and 2015/*** results indicate that the average turbulent heat fluxes in the polynya are about 87%and 86%higher than in the NSI area over the 10 years during the entire duration of the polynya and during polar night,*** turbulent heat fluxes from the polynya tend to produce more low-level *** relationship between the polynya and low cloud in winter was examined based on Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations(CALIPSO).The low-cloud fraction(0-2 km)was about 7%-34%larger over the polynya than the NSI area,and the ice water content below 200 m was about 250%-413%higher over the former than the *** correlation between cloud fraction and turbulent heat fluxes in the polynya peaks around the altitude of 200-300 *** results suggest that the NOW affects the Arctic boundary layer cloudiness and structure in ***,higher horizontal resolution reanalysis data can advance our understanding of the cloud-polynya response.

关键词： The North Water Polynya Turbulent heat fluxes Cloud cover Ice water content ASRv2 CALIPSO

来源：评论

学校读者我要写书评

暂无评论

Investigation on crack propagation of SiCf/SiC composite via PF-CZM method

引用

International Journal of Advanced Nuclear Reactor Design and technology 2024年第1期6卷 9-13页

作者： Qiu, Bowen Li, Zhuang Liang, Shuang Zhang, Cheng Wei, Chong Xiao, Zhong Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China School of Mechanical Civil Engineering and Architecture Northwestern Polytechnical University Xi'an710072 China Science and Technology on Thermo Structural Composite Materials Laboratory Northwestern Polytechnical University Xi'an710072 China

SiCf/SiC composite materials had become a research hotspot in the fields of aerospace materials and nuclear materials in recent years. This materials have high strength, radiation resistance, high temperature resistance and oxidation resistance. However, SiC is a typical brittle material prone to being damaged due to stress concentration in some cases, leading to cracks and even component failure. Therefore, this study employed an accurate and efficient numerical simulation method, phase field cohesive zone method (PFCZM), to investigate the microscopic damage behavior of SiCf/SiC composite materials. This study aimed to illustrate the influence of the thickness of pyrolytic carbon (PyC) interface layer on the failure behavior of SiCf/SiC composite materials. Firstly, this study conducted relevant verification of PFCZM. Secondly, numerical simulations of crack initiation, crack propagation, and final damage were performed by establishing a representative volume element (RVE). Observing the simulation results, it was noted that at low strain, when PyC was thicker, the SiCf/SiC composite materials exhibited slight damage to both the SiC matrix and PyC interface. Conversely, when PyC was thinner, the SiCf/SiC composite materials displayed only slight damage to PyC interface. As the PyC thickness increases, the damage to PyC interface decreases, while the damage to SiC becomes more prominent. Simultaneously, a competitive relationship in the damage behavior of SiCf/SiC composite materials can be found after the SiC matrix has cracked: When PyC is thinner, the damage primarily manifests as interlayer delamination between the SiC matrix and the SiC fiber. Conversely, when PyC is thicker, it manifests in PyC failure. Finally, this study concluded that, in this investigation, a PyC interface layer with a thickness of 0.1 μm exhibited the most effective protective effect on SiCf/SiC composite material. © 2024 Xi'an Jiaotong University

关键词： Crack propagation

来源：评论

学校读者我要写书评

暂无评论

A Real-time Demonstration of Bidirectional Multiformat/Rate-adjustable Integrated Laser Communication/Ranging for Satellite Communication

A Real-time Demonstration of Bidirectional Multiformat/Rate-...

引用

2024 Conference on Lasers and Electro-Optics, CLEO 2024

作者： Wang, Yizhou Wang, Yuanxiang Luo, Zhen Zhong, Linsheng Zou, Yang Ao, Xueyuan Liu, Jiale Fan, Feng Li, Xiaoliang Dai, Xiaoxiao Yang, Qi Liu, Deming National Engineering Laboratory for Next Generation Internet Access System School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan430074 China Hubei Key Laboratory of Distributed System Security Hubei Engineering Research Center on Big Data Security School of Cyber Science and Engineering Huazhong University of Science and Technology Wuhan430074 China Beijing Research Institute of Telemetry Beijing100094 China Jinyinhu Laboratory Wuhan430040 China

A multi-format/rate-adjustable integrated laser communication/ranging system is proposed, achieving adjustable rates between 0.625-10Gbit/s. Real-time experiment shows that at 1e-4 BER the ranging error is only 0.29% ... 详细信息

ISBN: (纸本)9781957171395

关键词： Laser theory

来源：评论

学校读者我要写书评

暂无评论

Convolutional Neural Networks Aided Reinforcement Learning for Accelerated Optimization of Antenna Topology

引用

Applied Computational Electromagnetics Society Journal 2025年第1期40卷 35-41页

作者： Dou, Jiangling Gong, Hao Wei, Shuaibing Chen, Haokang Chen, Yujie Shen, Tao Song, Jian Yunnan Key Laboratory of Computer Technologies Application Kunming University of Science and Technology Kunming650500 China School of Information Engineering and Automation Kunming University of Science and Technology Kunming650500 China College of Mechanical and Electrical Engineering Yunnan Electromechanical Vocational and Technical College Kunming650500 China

A machine learning (ML) framework is proposed to achieve the automatic and rapid optimization of antenna topologies. A convolutional neural network (CNN) is utilized as a surrogate model (SM) and is combined with reinforcement learning (RL) algorithms. Specifically, the RL agent interacts with simulation software to learn. Data accumulated from electromagnetic (EM) simulations are used to train the SM. The CNN-based SM predicts antenna performance based on the topology of the antenna. Subsequently, the SM replaces EM simulations within the RL training environment. The RL agent interacts with the CNN-based SM to search for the optimal topology. This approach significantly reduces dependence on time-consuming EM simulations. To validate the effectiveness of the optimization method, a center-fed microstrip patch antenna is optimized. Simulation results demonstrate that, compared to other optimization methods, impedance bandwidth is improved, while the number of simulation samples and optimization time are significantly reduced. © ACES.

关键词： Convolutional neural networks

来源：评论

学校读者我要写书评

暂无评论

Flat Zn deposition at battery anode via an ultrathin robust interlayer

引用

Nano Research 2024年第9期17卷 8104-8111页

作者： Yizhou Wang Jianyu Chen Zibo Chen Qian He Zhengnan Tian Jin Zhao Yanwen Ma Husam N.Alshareef Materials Science and Engineering King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia State Key Laboratory of Organic Electronics and Information Displays(KLOEID)and Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Nanjing University of Posts and TelecommunicationsNanjing 210023China Suzhou Vocational Institute of Industrial Technology Suzhou 215104China

Rechargeable aqueous zinc(Zn)ion batteries(AZIBs)using low-cost and safe Zn metal anodes are considered promising candidates for future grid-scale energy storage systems,but the Zn dendrite problem severely hinders the further prospects of *** Zn depositing behaviors toward horizontal alignment is highly effective and thus has received huge ***,such a strategy is usually based on previous substrate engineering,which requires complex preparation or expensive ***,it is essential to develop a novel solution that can realize horizontally aligned Zn flake deposition via easy operation and low ***,we report an ultrathin and robust Kevlar membrane as the interlayer to mechanically suppress Zn dendrite *** to the randomly distributed flaky dendrites in the control group,the deposited Zn sheets would grow into parallel alignment with the existence of such *** the dendrites are effectively suppressed,Zn||Cu asymmetric,Zn||Zn symmetric,and Zn||MnO_(2)full batteries using Kevlar interlayer deliver significantly improved cycling ***,the Zn||MnO_(2)pouch cell using a Kevlar interlayer delivers stable cycling performance and shows stable operation during multi-angle *** believe this work provides a new possibility for regulating Zn deposition from a crystallographic perspective.

关键词： Zn metal anodes Zn dendrites aqueous Zn ion batteries dendrite suppression (002)crystal plane

来源：评论

学校读者我要写书评

暂无评论

Underwater acoustic metamaterials

引用

National science Review 2023年第6期10卷 258-280页

作者： Erqian Dong Peizheng Cao Jinhu Zhang Sai Zhang Nicholas X.Fang Yu Zhang Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education College of Ocean and Earth Sciences Xiamen University State Key Laboratory of Marine Environmental Science Xiamen University School of Physics and Electronic Engineering Jiangsu University Department of Mechanical Engineering Massachusetts Institute of Technology

Acoustic metamaterials have been widely investigated over the past few decades and have realized acoustic parameters that are not achievable using conventional *** demonstrating that locally resonant acoustic metamaterials are capable of acting as subwavelength unit cells,researchers have evaluated the possibility of breaking the classical limitations of the material mass density and bulk *** with theoretical analysis,additive manufacturing and engineering applications,acoustic metamaterials have demonstrated extraordinary capabilities,including negative refraction,cloaking,beam formation and super-resolution *** to the complexity of impedance boundaries and mode transitions,there are still challenges in freely manipulating acoustic propagation in an underwater *** review summarizes the developments in underwater acoustic metamaterials over the past 20 years,which include underwater acoustic invisibility cloaking,underwater beam formation,underwater metasurfaces and phase engineering,underwater topological acoustics and underwater acoustic metamaterial *** the evolution of underwater metamaterials and the timeline of scientific advances,underwater acoustic metamaterials have demonstrated exciting applications in underwater resource development,target recognition,imaging,noise reduction,navigation and communication.

关键词： underwater acoustic metamaterials invisibility cloaking beam formation topological acoustics metasurfaces absorbers

来源：评论

学校读者我要写书评

暂无评论

Integrating GAT and LSTM for Robotic Arms Motion Planning 43

Integrating GAT and LSTM for Robotic Arms Motion Planning

引用

43rd Chinese Control Conference, CCC 2024

作者： Gao, Zehua Zhang, Junnan Liu, Zhaoyang Jiang, Zewu Wang, Ke Tianjin University Tianjin Key Laboratory of Intelligent Unmanned Swarm Technology and System School of Electrical and Information Engineering Tianjin300072 China

ISBN: (纸本)9789887581581

In the field of robotic arm control, efficient motion planning, especially in environments with multiple arms, poses significant challenges, including longer planning times and extensive collision detection in complex scenes. We use a learning based approach to solve this problem. This paper proposes a motion planning algorithm that integrates graph attention network (GAT) and Long Short-Term Memory (LSTM) network for the problem of motion planning of two robotic arms. This method uses imitation learning to train the control strategy of the robotic arm, constructs graph nodes through sampling, and encodes the trajectory of the robotic arm using LSTM. The experimental results show that compared with advanced planning algorithms in dynamic environments, our algorithm can maintain similar success rates while reducing collision detection and accelerating online planning speed. © 2024 Technical Committee on Control Theory, Chinese Association of Automation.

关键词： Robotic arms

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：