期刊文献+
共找到38,263篇文章
< 1 2 250 >
每页显示 20 50 100
Multi-functional photonic spin Hall effect sensor controlled by phase transition
1
作者 程杰 李瑞昭 +3 位作者 程骋 张亚林 刘胜利 董鹏 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期336-342,共7页
Photonic spin Hall effect(PSHE), as a novel physical effect in light–matter interaction, provides an effective metrological method for characterizing the tiny variation in refractive index(RI). In this work, we propo... Photonic spin Hall effect(PSHE), as a novel physical effect in light–matter interaction, provides an effective metrological method for characterizing the tiny variation in refractive index(RI). In this work, we propose a multi-functional PSHE sensor based on VO_(2), a material that can reveal the phase transition behavior. By applying thermal control, the mutual transformation into different phase states of VO_(2) can be realized, which contributes to the flexible switching between multiple RI sensing tasks. When VO_(2) is insulating, the ultrasensitive detection of glucose concentrations in human blood is achieved. When VO_(2) is in a mixed phase, the structure can be designed to distinguish between the normal cells and cancer cells through no-label and real-time monitoring. When VO_(2) is metallic, the proposed PSHE sensor can act as an RI indicator for gas analytes. Compared with other multi-functional sensing devices with the complex structures, our design consists of only one analyte and two VO_(2) layers, which is very simple and elegant. Therefore, the proposed VO_(2)-based PSHE sensor has outstanding advantages such as small size, high sensitivity, no-label, and real-time detection, providing a new approach for investigating tunable multi-functional sensors. 展开更多
关键词 photonic spin Hall effect multi-functional sensors phase transition sensing performance
下载PDF
Design of Drilling and Riveting Multi-functional End Effector for CFRP and Aluminum Components in Robotic Aircraft Assembly 被引量:6
2
作者 Zhang Lin Tian Wei +4 位作者 Li Dawei Hong Peng Li Zhenyu Zhou Weixue Liao Wenhe 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第3期529-538,共10页
To fulfill the demands for higher quality,efficiency and flexibility in aviation industry,a multi-functional end effector is designed to automate the drilling and riveting processes in assembling carbon fiber reinforc... To fulfill the demands for higher quality,efficiency and flexibility in aviation industry,a multi-functional end effector is designed to automate the drilling and riveting processes in assembling carbon fiber reinforced polymer(CFRP)and aluminum components for a robotic aircraft assembly system.To meet the specific functional requirements for blind rivet installation on CFRP and aluminum materials,additional modules are incorporated on the end effector aside of the basic processing modules for drilling.And all of these processing modules allow for a onestep-drilling-countersinking process,hole inspection,automatic rivet feed,rivet geometry check,sealant application,rivet insertion and installation.Besides,to guarantee the better quality of the hole drilled and joints riveted,several online detection and adjustment measures are applied to this end effector,including the reference detection and perpendicular calibration,which could effectively ensure the positioning precision and perpendicular accuracy as demanded.Finally,the test result shows that this end effector is capable of producing each hole to a positioning precision within ±0.5 mm,aperpendicular accuracy within 0.3°,a diameter tolerance of H8,and a countersink depth tolerance of±0.01 mm.Moreover,it could drill and rivet up to three joints per minute,with acceptable shearing and tensile strength. 展开更多
关键词 robotic aircraft assembly CFRP and aluminum components automatic drilling and riveting multi-functional end effector online detection and adjustment
下载PDF
Development of a novel multi-functional integrated bioconjugate effectively targeting K-Ras mutant pancreatic cancer 被引量:1
3
作者 Yang-Yang Wang Liang Li +4 位作者 Xiu-Jun Liu Qing-Fang Miao Yi Li Meng-Ran Zhang Yong-Su Zhen 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2022年第2期232-242,共11页
Folate receptor(FR)overexpression occurs in a variety of cancers,including pancreatic cancer.In addition,enhanced macropinocytosis exists in K-Ras mutant pancreatic cancer.Furthermore,the occurrence of intensive desmo... Folate receptor(FR)overexpression occurs in a variety of cancers,including pancreatic cancer.In addition,enhanced macropinocytosis exists in K-Ras mutant pancreatic cancer.Furthermore,the occurrence of intensive desmoplasia causes a hypoxic microenvironment in pancreatic cancer.In this study,a novel FR-directed,macropinocytosis-enhanced,and highly cytotoxic bioconjugate folate(F)-human serum albumin(HSA)-apoprotein of lidamycin(LDP)-active enediyne(AE)derived from lidamycin was designed and prepared.F-HSA-LDP-AE consisted of four moieties:F,HSA,LDP,and AE.F-HSA-LDP presented high binding efficiency with the FR and pancreatic cancer cells.Its uptake in wild-type cells was more extensive than in K-Ras mutant-type cells.By in vivo optical imaging,F-HSA-LDP displayed prominent tumor-specific biodistribution in pancreatic cancer xenograft-bearing mice,showing clear and lasting tumor localization for 360 h.In the MTT assay,F-HSA-LDP-AE demonstrated potent cytotoxicity in three types of pancreatic cancer cell lines.It also induced apoptosis and caused G2/M cell cycle arrest.F-HSALDP-AE markedly suppressed the tumor growth of AsPc-1 pancreatic cancer xenografts in athymic mice.At well-tolerated doses of 0.5 and 1 mg/kg,(i.v.,twice),the inhibition rates were 91.2%and 94.8%,respectively(P<0.01).The results of this study indicate that the F-HSA-LDP multi-functional bioconjugate might be effective for treating K-Ras mutant pancreatic cancer. 展开更多
关键词 Pancreatic cancer Folate receptor multi-functional Macropinocytosis-enhanced BIOCONJUGATE K-RAS PEGYLATION
下载PDF
Ship-YOLOv8:一种轻量级高分辨遥感图像船舶细粒度检测算法
4
作者 陈燕奎 龙超活 +2 位作者 何骏杰 张豫 谢作轮 《现代信息科技》 2024年第22期25-29,35,共6页
针对高分辨率影像的船舶细粒度目标检测分类任务中类内差异大、类间相似性高、物体和场景的尺度变化范围大、特征提取困难、样本小等特点,提出了一种基于YOLOv8为基础的改进算法。首先,在骨干网络中引入SimAM注意力机制,使得模型在复杂... 针对高分辨率影像的船舶细粒度目标检测分类任务中类内差异大、类间相似性高、物体和场景的尺度变化范围大、特征提取困难、样本小等特点,提出了一种基于YOLOv8为基础的改进算法。首先,在骨干网络中引入SimAM注意力机制,使得模型在复杂背景中更加聚焦船舶对象;其次,在颈部引入SPD-Conv模块,改善复杂背景下船舶尺度变化大和小目标检测的问题;最后针对细粒度船舶目标检测的特点,替换Mish激活函数和Focal-Loss损失函数,加快模型收敛,提高模型精度。经对比实验可知,改进的算法在保证检测速度和模型参数量的同时,在FAIR1M_Ship数据集取得了94.49%的检测精度,与目前流行的目标检测算法相比,在检测精度上有一定的提升。 展开更多
关键词 船舶 目标识别 遥感图像 细粒度识别 YOLOv8
下载PDF
Multi-functional optical fiber sensor system based on a dense wavelength division multiplexer
5
作者 Yue-Xin Yin Zhifa Wu +4 位作者 Siwen Sun Liang Tian Xibin Wang Yuanda Wu Daming Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第7期222-224,共3页
We propose a novel and efficient multi-functional optical fiber sensor system based on a dense wavelength division multiplexer(DWDM).This system consists of an optical fiber temperature sensor, an optical fiber strain... We propose a novel and efficient multi-functional optical fiber sensor system based on a dense wavelength division multiplexer(DWDM).This system consists of an optical fiber temperature sensor, an optical fiber strain sensor, and a 48-channel DWDM.This system can monitor temperature and strain changes at the same time.The ranges of these two sensors are from-20℃ to 100℃ and from-1000 με to 2000 με, respectively.The sensitivities of the temperature sensor and strain sensor are 0.03572 nm/℃ and 0.03808 nm/N, respectively.With the aid of a broadband source and spectrometer,different kinds and ranges of parameters in the environment can be monitored by using suitable sensors. 展开更多
关键词 DENSE wavelength DIVISION multiplexer(DWDM) planar LIGHTWAVE circuit multi-functional SENSOR optical fiber SENSOR system
下载PDF
A design and application of compound multi-functional sensor in wood-based panel processing
6
作者 XU Kai-hong ZHOU Ding-guo 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第4期319-322,共4页
A compound multi-functional sensor was designed by the study on the on-line testing technology of wood-based panels, and its properties of shape, functions, size, resistance to special environment were studied in deta... A compound multi-functional sensor was designed by the study on the on-line testing technology of wood-based panels, and its properties of shape, functions, size, resistance to special environment were studied in details. The operational principles of different sensors, technical flow of manufacturing, development of software systems of special functions, and the assessments of technical specification were also be introduced. This sensor adopted many new technologies, such as the applications of piezoresistant effect and heat sensitive effect can effectively measure the pressure and temperature, digital signal processing technology was used to extract and treat signals, and resist interference, encapsulation technology was used to keep the normal run of sensor under a harsh environment. Thus, the on-line compound multi-functional temperature/pressure sensor can be applied better to supervise the production of wood-based panels. All technical specifications of the compound multi-functional sensor were tested and the results met the requirements of the equipments. 展开更多
关键词 Wood-based panel processing multi-functional sensor Piezoresistant effect Heat sensitive effect
下载PDF
Quasi-distribution Appraisal about Finite Element Analysis of Multi-functional Structure Made of Honeycomb Sandwich Materials
7
作者 王一多 SHI Xiaofei +1 位作者 XI Ping LANG Haitao 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第1期30-34,共5页
A new appraisal method(QDA, quasi-distribution appraisal) which could be used to evaluate the finite element analysis of multi-functional structure made of honeycomb sandwich materials is developed based on sub-sect... A new appraisal method(QDA, quasi-distribution appraisal) which could be used to evaluate the finite element analysis of multi-functional structure made of honeycomb sandwich materials is developed based on sub-section Bezier curve. It is established by simulating the distribution histogram data obtained from the numerical finite element analysis values of a satellite component with sub-section Bezier curve. Being dealt with area normalization method, the simulation curve could be regarded as a kind of probability density function(PDF), its mathematical expectation and the variance could be used to evaluate the result of finite element analysis. Numerical experiments have indicated that the QDA method demonstrates the intrinsic characteristics of the finite element analysis of multi-functional structure made of honeycomb sandwich materials, as an appraisal method, it is effective and feasible. 展开更多
关键词 honeycomb sandwich materials multi-functional structure quasi-distribution finite element analysis
下载PDF
Considering calcium-binding proteins in invertebrates: multi-functional proteins that shape neuronal growth
8
作者 Charles R.Tessier 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第2期208-209,共2页
Calcium is a critical second messenger molecule in all cells and is vital in neurons for synaptic transmission.Given this importance,calcium ions are tightly controlled by a host of molecular players including ion cha... Calcium is a critical second messenger molecule in all cells and is vital in neurons for synaptic transmission.Given this importance,calcium ions are tightly controlled by a host of molecular players including ion channels,sensors,and buffering proteins.Calcium can act directly by binding to signaling molecules or calcium’s effects can be indirect,for example by altering nuclear histones. 展开更多
关键词 Considering calcium-binding proteins in invertebrates multi-functional proteins that shape neuronal growth
下载PDF
Analysis of Dynamic Cross Response between Spindles in a Dual Spindle Type Multi-Functional Turning Machine
9
作者 Y. H. Choi S. T. Kim +1 位作者 T. Y. Seo K. H. Kim 《Journal of Power and Energy Engineering》 2013年第7期20-24,共5页
In order to meet increasing demand for higher productivity and flexibility, recently many kinds of multi-functional machine tools, which are capable of multiple machining functions or different kinds of machining proc... In order to meet increasing demand for higher productivity and flexibility, recently many kinds of multi-functional machine tools, which are capable of multiple machining functions or different kinds of machining processes on one machine, have been developed and widely used in manufacturing industries. In this study, a multi-functional turning lathe, which has two spindles and two turrets so that multiple turning operations and various machining processes could be performed simultaneously, has been developed. Furthermore, the equations of correlation between whole responses and cross responses of the two spindles have been derived to examine to what extent the two spindles affect each other’s vibrations. 展开更多
关键词 multi-functional LATHE Multi-Spindles Frequency RESPONSE CROSS RESPONSE FEM Structural ANALYSIS
下载PDF
Design and Development of a Multi-functional Laparoscopic Device
10
作者 Tugrul Tansug Elif Taskin +1 位作者 Eray Kurt Meltem Elitas 《Journal of Mechanics Engineering and Automation》 2019年第5期173-176,共4页
This study presents a design of a multifunctional laparoscopic appendectomy device that includes three surgical instruments commonly used in laparoscopic appendicitis surgeries:endoloop,endobag and scissors.It collect... This study presents a design of a multifunctional laparoscopic appendectomy device that includes three surgical instruments commonly used in laparoscopic appendicitis surgeries:endoloop,endobag and scissors.It collects these three independent surgical tools in a single laparoscopic appendectomy device.These days there is a trend of moving to multi-functional surgery devices during minimally invasive surgery.The main reasons behind the minimal invasive surgery are to avoid changing the devices several times during the operation,to reduce the time spent in operation,to increase the efficiency of the operation,to facilitate the follow-up of the camera and devices,and to leave trocars to be used for other surgical instruments.The multi-functional appendectomy device that,we present here,provides these benefits.The standard trocar entries are appropriate for its usage.The presented multifunctional laparoscopic appendectomy device offers more practical use in comparison to individual devices.On the other hand,development of these multi-functional surgery devices can be directly enhanced to the robotic surgery devices. 展开更多
关键词 Apendectomy multi-functional LAPAROSCOPY SOLIDWORKS SURGERY
下载PDF
Design and Development of a Forest Nursery, for the Enhancement of Multi-Functional Agriculture and for a Didactical Purpose
11
作者 Elena Valent Sirio Rossano Secondo Cividino +4 位作者 Marco Barbaro Luisa Dalla Costa Stefano Santi Simona Rainis Rino Gubiani 《Journal of Life Sciences》 2013年第8期892-900,共9页
The experimental idea of the present project was elaborated in order to create a structure where different categories and institutions could collaborate, with the common aim to develop a sustainable and profitable agr... The experimental idea of the present project was elaborated in order to create a structure where different categories and institutions could collaborate, with the common aim to develop a sustainable and profitable agriculture in mountain and marginal areas. The target was the recovering of an abandoned agricultural site, throughout its re-organisation, re-qualification and auto-sustainability, involving local citizens. This approach was based on three further broad functions such as environmental, economic and social purposes. This cooperation, that allows the capitalization of local knowledge and the forging of relationships between local and external sources of expertise, information and advice, is fundamental to the future of existing rural communities, in particular in mountain areas. The model proposed, with the elaboration of a management software and technical agronomic sheets, could be an incentive for the activities already present in that region and to stimulate new ones. The enhancing of the native ecological system, the biodiversity tutelage and the valorization of the knowledge of the territory is the basic requirement for the successful of any land management. 展开更多
关键词 Innovative sustainable and multi-functional agriculture recovering of disused agronomic areas biodiversity tutelage horticulture.
下载PDF
A Portable Multi-functional Real-time Digital Simulator Dedicated to Protective Relay Testing
12
作者 Liang Zhicheng Ma Xiandong +1 位作者 Wang Haixian Wang Like (Nanjing Automation Research Institute (NARI)) 《Electricity》 1998年第4期27-29,共3页
The paper intfoduces a PC-DSP based real-time digital simulator which is portable in size and aimed at the closed-loop testing of various types of protective relays for their design and application. The simulator can ... The paper intfoduces a PC-DSP based real-time digital simulator which is portable in size and aimed at the closed-loop testing of various types of protective relays for their design and application. The simulator can be widely used in not only concerning utilities but also manufacturers and research / certification institutes because of its many functions. The hardware architecture and software implementation of the simulator are described. The main features and functions of the simulator are also 展开更多
关键词 TIME A Portable multi-functional Real-time Digital Simulator Dedicated to Protective Relay Testing MMI
下载PDF
MULTI-FUNCTIONAL EQUIPMENT MAINTENANCE AGENT
13
《China Oil & Gas》 CAS 1997年第4期227-227,共1页
关键词 multi-functional EQUIPMENT MAINTENANCE AGENT
下载PDF
A Framework of LSTM Neural Network Model in Multi-Time Scale Real-Time Prediction of Ship Motions in Head Waves
14
作者 CHEN Zhan-yang ZHAN Zheng-yong +2 位作者 CHANG Shao-ping XU Shao-feng LIU Xing-yun 《船舶力学》 EI CSCD 北大核心 2024年第12期1803-1819,共17页
Ship motions induced by waves have a significant impact on the efficiency and safety of offshore operations.Real-time prediction of ship motions in the next few seconds plays a crucial role in performing sensitive act... Ship motions induced by waves have a significant impact on the efficiency and safety of offshore operations.Real-time prediction of ship motions in the next few seconds plays a crucial role in performing sensitive activities.However,the obvious memory effect of ship motion time series brings certain difficulty to rapid and accurate prediction.Therefore,a real-time framework based on the Long-Short Term Memory(LSTM)neural network model is proposed to predict ship motions in regular and irregular head waves.A 15000 TEU container ship model is employed to illustrate the proposed framework.The numerical implementation and the real-time ship motion prediction in irregular head waves corresponding to the different time scales are carried out based on the container ship model.The related experimental data were employed to verify the numerical simulation results.The results show that the proposed method is more robust than the classical extreme short-term prediction method based on potential flow theory in the prediction of nonlinear ship motions. 展开更多
关键词 deep learning LSTM ship motion real-time prediction irregular waves
下载PDF
Numerical Simulation of Multiple Collisions Between Ice Ridge and Polar Ship
15
作者 JIA Bin JU Lei +2 位作者 SHI Li WANG Qing PANG Fu-zhen 《船舶力学》 EI CSCD 北大核心 2024年第12期1908-1924,共17页
Ships navigating in ice-covered regions will inevitably collide with ice ridges.Compared to other ice bodies,ice ridges exhibit more complicated mechanical behaviors due to the scale and structure characteristics.In t... Ships navigating in ice-covered regions will inevitably collide with ice ridges.Compared to other ice bodies,ice ridges exhibit more complicated mechanical behaviors due to the scale and structure characteristics.In this paper,nonlinear finite element method is used to investigate the interaction between a polar ship and an ice ridge.The ice ridge is modelled as elastic-plastic material based on Drucker-Prager yield function,with the consideration of the influence of cohesion,friction angle and material hardening.The material model is developed in LS-DYNA and solved using semi-implicit mapping algorithm.The stress distribution of ice ridge and ship,and the ice load history are evaluated through the simulation of multiple collisions.In addition,parametric analysis is performed to investigate the influence of ridge thickness and impact velocity on the ice load and energy absorption. 展开更多
关键词 ice ridge ship nonlinear FEM ice load INTERACTION STRENGTH
下载PDF
Unmanned Ship Identification Based on Improved YOLOv8s Algorithm
16
作者 Chun-Ming Wu Jin Lei +2 位作者 Wu-Kai Liu Mei-Ling Ren Ling-Li Ran 《Computers, Materials & Continua》 SCIE EI 2024年第3期3071-3088,共18页
Aiming at defects such as low contrast in infrared ship images,uneven distribution of ship size,and lack of texture details,which will lead to unmanned ship leakage misdetection and slow detection,this paper proposes ... Aiming at defects such as low contrast in infrared ship images,uneven distribution of ship size,and lack of texture details,which will lead to unmanned ship leakage misdetection and slow detection,this paper proposes an infrared ship detection model based on the improved YOLOv8 algorithm(R_YOLO).The algorithm incorporates the Efficient Multi-Scale Attention mechanism(EMA),the efficient Reparameterized Generalized-feature extraction module(CSPStage),the small target detection header,the Repulsion Loss function,and the context aggregation block(CABlock),which are designed to improve the model’s ability to detect targets at multiple scales and the speed of model inference.The algorithm is validated in detail on two vessel datasets.The comprehensive experimental results demonstrate that,in the infrared dataset,the YOLOv8s algorithm exhibits improvements in various performance metrics.Specifically,compared to the baseline algorithm,there is a 3.1%increase in mean average precision at a threshold of 0.5(mAP(0.5)),a 5.4%increase in recall rate,and a 2.2%increase in mAP(0.5:0.95).Simultaneously,while less than 5 times parameters,the mAP(0.5)and frames per second(FPS)exhibit an increase of 1.7%and more than 3 times,respectively,compared to the CAA_YOLO algorithm.Finally,the evaluation indexes on the visible light data set have shown an average improvement of 4.5%. 展开更多
关键词 Unmanned ships R_YOLO EMA CSPStage YOLOv8s
下载PDF
Theoretical and Experimental Research of High-Static-Low Dynamic Torsional Vibration Isolator for Ship Shafting
17
作者 LI Lin-tao LU Jia-zhong +2 位作者 YANG Zhi-rong XIAO Wang-qiang RAO Zhu-shi 《船舶力学》 EI CSCD 北大核心 2024年第12期1970-1982,共13页
High-static-low-dynamic stiffness (HSLDS) vibration isolators have been demonstrated to be an effective means of attenuating low-frequency vibrations, and may be utilized for ship shafting applications to mitigate tor... High-static-low-dynamic stiffness (HSLDS) vibration isolators have been demonstrated to be an effective means of attenuating low-frequency vibrations, and may be utilized for ship shafting applications to mitigate torsional vibration. This paper presents the construction of a highly compact HSLDS torsional vibration isolator by connecting positive and negative stiffness components in paral lel. Based on mechanical model analysis, the restoring torque of negative stiffness components is de rived from their springs and connecting rods, while that of positive stiffness components is obtained through their circular section flexible rods. The quasizero stiffness characteristics of the HSLDS iso lator are achieved through a combination of static structural simulation and experimental test. The tor sional vibration isolation performance is assessed by means of numerical simulation and theory analy sis. Finally, the frequency-sweep vibration test is conducted. The test results indicate that the HSLDS torsional vibration isolator exhibits superior low-frequency isolation performance compared to its linear counterpart, rendering it a promising solution for mitigating low-frequency torsional vi bration in ship shafting. 展开更多
关键词 ship shafting high-static-low-dynamic stiffness torsional vibration isolator
下载PDF
Efficient Ship:A Hybrid Deep Learning Framework for Ship Detection in the River
18
作者 Huafeng Chen Junxing Xue +2 位作者 Hanyun Wen Yurong Hu Yudong Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期301-320,共20页
Optical image-based ship detection can ensure the safety of ships and promote the orderly management of ships in offshore waters.Current deep learning researches on optical image-based ship detection mainly focus on i... Optical image-based ship detection can ensure the safety of ships and promote the orderly management of ships in offshore waters.Current deep learning researches on optical image-based ship detection mainly focus on improving one-stage detectors for real-time ship detection but sacrifices the accuracy of detection.To solve this problem,we present a hybrid ship detection framework which is named EfficientShip in this paper.The core parts of the EfficientShip are DLA-backboned object location(DBOL)and CascadeRCNN-guided object classification(CROC).The DBOL is responsible for finding potential ship objects,and the CROC is used to categorize the potential ship objects.We also design a pixel-spatial-level data augmentation(PSDA)to reduce the risk of detection model overfitting.We compare the proposed EfficientShip with state-of-the-art(SOTA)literature on a ship detection dataset called Seaships.Experiments show our ship detection framework achieves a result of 99.63%(mAP)at 45 fps,which is much better than 8 SOTA approaches on detection accuracy and can also meet the requirements of real-time application scenarios. 展开更多
关键词 ship detection deep learning data augmentation object location object classification
下载PDF
Fine-Grained Ship Recognition Based on Visible and Near-Infrared Multimodal Remote Sensing Images: Dataset,Methodology and Evaluation
19
作者 Shiwen Song Rui Zhang +1 位作者 Min Hu Feiyao Huang 《Computers, Materials & Continua》 SCIE EI 2024年第6期5243-5271,共29页
Fine-grained recognition of ships based on remote sensing images is crucial to safeguarding maritime rights and interests and maintaining national security.Currently,with the emergence of massive high-resolution multi... Fine-grained recognition of ships based on remote sensing images is crucial to safeguarding maritime rights and interests and maintaining national security.Currently,with the emergence of massive high-resolution multi-modality images,the use of multi-modality images for fine-grained recognition has become a promising technology.Fine-grained recognition of multi-modality images imposes higher requirements on the dataset samples.The key to the problem is how to extract and fuse the complementary features of multi-modality images to obtain more discriminative fusion features.The attention mechanism helps the model to pinpoint the key information in the image,resulting in a significant improvement in the model’s performance.In this paper,a dataset for fine-grained recognition of ships based on visible and near-infrared multi-modality remote sensing images has been proposed first,named Dataset for Multimodal Fine-grained Recognition of Ships(DMFGRS).It includes 1,635 pairs of visible and near-infrared remote sensing images divided into 20 categories,collated from digital orthophotos model provided by commercial remote sensing satellites.DMFGRS provides two types of annotation format files,as well as segmentation mask images corresponding to the ship targets.Then,a Multimodal Information Cross-Enhancement Network(MICE-Net)fusing features of visible and near-infrared remote sensing images,has been proposed.In the network,a dual-branch feature extraction and fusion module has been designed to obtain more expressive features.The Feature Cross Enhancement Module(FCEM)achieves the fusion enhancement of the two modal features by making the channel attention and spatial attention work cross-functionally on the feature map.A benchmark is established by evaluating state-of-the-art object recognition algorithms on DMFGRS.MICE-Net conducted experiments on DMFGRS,and the precision,recall,mAP0.5 and mAP0.5:0.95 reached 87%,77.1%,83.8%and 63.9%,respectively.Extensive experiments demonstrate that the proposed MICE-Net has more excellent performance on DMFGRS.Built on lightweight network YOLO,the model has excellent generalizability,and thus has good potential for application in real-life scenarios. 展开更多
关键词 Multi-modality dataset ship recognition fine-grained recognition attention mechanism
下载PDF
Surface Pressure Loading Technology of Ship Structures
20
作者 DAI Ze-yu WEI Peng-yu +3 位作者 CHEN Xiao-ping JIANG Ze CHEN Zhe TANG Qin 《船舶力学》 EI CSCD 北大核心 2024年第12期1940-1952,共13页
A hull structure is prone to local deformation and damage due to the pressure load on the surface.How to simulate surface pressure is an important issue in ship structure test.The loading mode of hydraulic actuator co... A hull structure is prone to local deformation and damage due to the pressure load on the surface.How to simulate surface pressure is an important issue in ship structure test.The loading mode of hydraulic actuator combined with high-pressure flexible bladder was proposed,and the numerical model of the loading device based on flexible bladder was established.The design and analysis method of high-pressure flexible bladder based on aramid-fiber reinforced thermoplastic polyurethane was proposed to break through the surface pressure loading technology of ship structures.The surface pressure loading system based on flexible bladder was developed.The ultimate strength verification test of the box girder under the combined action of bending moment and pressure was carried out to systematically verify the feasibility and applicability of the loading system.The results show that the surface pressure loading technology can be used well for applying uniform pressure to ship structures.Compared with the traditional surface loading methods,the improved device can be applied with horizontal constant pressure load,with rapid response and safe process,and the pressure load is always stable with the increase of the bending moment load during the test.The requirement for uniform loading in the comprehensive strength test of large structural models is satisfied and the accuracy of the test results is improved by this system. 展开更多
关键词 surface pressure load loading system ship structure strength test flexible bladder
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部