检索结果-南通市图书馆

YOLOv5ST:A Lightweight and Fast Scene Text Detector

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第4期79卷 909-926页

作者： Yiwei liu Yingnan Zhao Yi Chen zheng Hu min Xia School of Computer and Science Nanjing University of Information Science and TechnologyNanjing210044China School of Automation Nanjing University of Information Science and TechnologyNanjing210044China

Scene text detection is an important task in computer *** this paper,we present YOLOv5 Scene Text(YOLOv5ST),an optimized architecture based on YOLOv5 v6.0 tailored for fast scene text *** primary goal is to enhance inference speed without sacrificing significant detection accuracy,thereby enabling robust performance on resource-constrained devices like drones,closed-circuit television cameras,and other embedded *** achieve this,we propose key modifications to the network architecture to lighten the original backbone and improve feature aggregation,including replacing standard convolution with depth-wise convolution,adopting the C2 sequence module in place of C3,employing Spatial Pyramid Pooling Global(SPPG)instead of Spatial Pyramid Pooling Fast(SPPF)and integrating Bi-directional Feature Pyramid Network(BiFPN)into the *** results demonstrate a remarkable 26%improvement in inference speed compared to the baseline,with only marginal reductions of 1.6%and 4.2%in mean average precision(mAP)at the intersection over union(IoU)thresholds of 0.5 and 0.5:0.95,*** work represents a significant advancement in scene text detection,striking a balance between speed and accuracy,making it well-suited for performance-constrained environments.

关键词： Scene text detection YOLOv5 lightweight object detection

Universal method for designing periodic orbits by homotopy classes in the elliptic restricted three-body problem

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Astrodynamics 2024年第1期8卷 175-188页

作者： Yue zheng min Zhao School of Electronic Engineering Xi’an Aeronautical InstituteXi’an710077China School of Aircraft Engineering Xi’an Aeronautical InstituteXi’an710077China School of Astronautics Northwestern Polytechnical UniversityXi’an710072China

The current methods for designing periodic orbits in the elliptic restricted three-body problem(ERTBP)have the disadvantages of targeting limited orbits and ergodic searches and considering only symmetric orbits.A universal method for designing periodic orbits is proposed in this ***,the homotopy classes of orbits are structured based on their topological ***,a dynamic model based on homotopy classes,ranging from the circular restricted three-body problem(CRTBP)to the ERTBP,can be built using the homotopy ***,a multi-and a single-period orbit were selected based on the resonance ***,the corresponding orbit in the ERTBP was computed by modifying the initial condition of the orbit in the *** method,without an ergodic search,can extend to any orbit,including an asymmetric orbit in the CRTBP,to the ERTBP model,and the two orbits are of the same homotopy *** of the Earth–Moon ERTBP are presented to verify the efficiency of this method.

关键词： periodic orbit elliptic restricted three-body problem(ERTBP) topology homotopy circular restricted three-body problem(CRTBP)

On-demand engineerable visible spectrum by fine control of electrochemical reactions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 239-249页

作者： Qirong liu Lei liu Yongping zheng min Li Baofu Ding Xungang Diao Hui-ming Cheng Yongbing Tang Advanced Energy Storage Technology Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences Institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences School of Energy and Power Engineering North University of China School of Resource Environment and Safety EngineeringHunan University of Science and Technology School of Energy and Power Engineering Beihang University Shenzhen Key Laboratory of Energy Materials for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

Tunability of optical performance is one of the key technologies for adaptive optoelectronic applications,such as camouflage clothing, displays, and infrared shielding. High-precision spectral tunability is of great importance for some special applications with on-demand adaptability but remains challenging. Here we demonstrate a galvanostatic control strategy to achieve this goal, relying on the finding of the quantitative correlation between optical properties and electrochemical reactions within materials. An electrochromic electro-optical efficiency index is established to optically fingerprint and precisely identify electrochemical redox reactions in the electrochromic device. Consequently, the charge-transfer process during galvanostatic electrochemical reaction can be quantitatively regulated, permitting precise control over the final optical performance and on-demand adaptability of electrochromic devices as evidenced by an ultralow deviation of <3.0%. These findings not only provide opportunities for future adaptive optoelectronic applications with strict demand on precise spectral tunability but also will promote in situ quantitative research in a wide range of spectroelectrochemistry, electrochemical energy storage, electrocatalysis, and material chemistry.

关键词： electrochromics fine control spectral tunability high precision galvanostatic control

Design of efficient thermoelectric generators

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Materials 2024年第1期67卷 377-378页

作者： min liu Yanzhong Pei Interdisciplinary Materials Research Center School of Materials Science and EngineeringTongji UniversityShanghai 201804China

Thermoelectricity,which enables direct conversion between heat and electricity,undergoes impressive developments in recent decades,and is particularly promising for recovering low-grade heat of<600 K[1,2].Currently,only Bi2Te3-based thermoelectric devices are commercialized[3].However,the scarcity of tellurium(Te)(Fig.1a)is the main *** leads to numerous recent efforts on the development of efficient nonBi2Te3 thermoelectrics as potential alternatives,and successful examples(Fig.1b)include Mg3Sb2-alloys[2,3]and MgAgSb[1,2].

关键词： enable efficient electricity

Role of CD36 in central nervous system diseases

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第3期19卷 512-518页

作者： min Feng Qiang Zhou Huimin Xie Chang liu Mengru zheng Shuyu Zhang Songlin Zhou Jian Zhao School of Health Science and Engineering University of Shanghai for Science and TechnologyShanghaiChina Department of Orthopedic Oncology Second Affiliated Hospital of Naval Medical UniversityShanghaiChina Key Laboratory of Neuroregeneration of Jiangsu and ministry of Education NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology ProductsJiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury RepairCo-Innovation Center of NeuroregenerationNantong UniversityNantongJiangsu ProvinceChina Department of Stomatology Affiliated Hospital of Nantong UniversityNantongJiangsu ProvinceChina Medical College of Nantong University NantongJiangsu ProvinceChina

CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic ***36 was recently found to be widely expressed in various cell types in the nervous system,including endothelial cells,pericytes,astrocytes,and ***36 mediates a number of regulatory processes,such as endothelial dysfunction,oxidative stress,mitochondrial dysfunction,and inflammatory responses,which are involved in many central nervous system diseases,such as stroke,Alzheimer’s disease,Parkinson’s disease,and spinal cord ***36 antagonists can suppress CD36 expression or prevent CD36 binding to its ligand,thereby achieving inhibition of CD36-mediated pathways or ***,we reviewed the mechanisms of action of CD36 antagonists,such as Salvianolic acid B,tanshinone IIA,curcumin,sulfosuccinimidyl oleate,antioxidants,and small-molecule ***,we predicted the structures of binding sites between CD36 and *** sites can provide targets for more efficient and safer CD36 antagonists for the treatment of central nervous system diseases.

关键词： animal experiments antagonists CD36 antagonist central nervous system diseases clinical trial curcumin microRNA salvianolic acid B small-molecule drugs sulfosuccinimidyl oleate

Effect of Pre-strain on Microstructure and Stamping Performance of High-strength Low-alloy Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 774-780页

作者：刘坡 WEN Zhicheng liu zheng 许峰 School of Mechanical Engineering Guilin University of Aerospace TechnologyGuilin 541004China School of Automotive Engineer-ing Changshu Institute of TechnologyChangshu 215500China

In this study,pre-strain ranging from 0 to 0.12 was applied through uniaxial tension on high-strength low-alloy(HSLA)specimens with four kinds of grain *** of pre-strain and grain size on me-chanical property was investigated through tensile *** of the pre-strained and tensile tested samples were analyzed,*** 30.8°v-bending and following flattening,as well as Erichson cupping tests,were performed on the pre-strained *** show the elongation ratio of grain and dislocation density increases with *** platform is removed when pre-strain is larger than 0.06 while yielding plateau period decreases with pre-strain less than 0.06 due to reduction of pinning *** 30.8°v-bending and the following flattening tests are successfully accomplished on all the pre-strained samples with different grain *** in grain size,along with increase in pre-strain,causes increase in strength and decrease in elongation rate as well as cupping ***-strain causes very slight effect on bending ability,much less than that on mechanical property and cupping test *** impact of the pre-strain and grain size on HSLA steel deformability is inconspicuous.

关键词： strain hardening dislocation texture bending erichson cupping test

Polynomial-Time Key-Recovery Attacks Against NTRURe Encrypt from ASIACCS'15

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第3期37卷 1308-1325页

作者： liu Zhen PAN Yanbin zheng Jinwei School of Cyber Science and Technology Hubei Key Laboratory of Applied MathematicsHubei UniversityWuhan 430062China Key Laboratory of Mathematics Mechanization Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100190China

In ASIACCS 2015, Nu nez, et al. proposed a proxy re-encryption scheme, named NTRURe Encrypt, based on NTRU, which allows a proxy to translate ciphertext under the delegator’s public key into a re-encrypted ciphertext that can be decrypted correctly by delegatee’s private key. Because of the potential resistance to quantum algorithm, high efficiency and various applications in real life,NTRURe Encrypt has drawn lots of attention and its security has been widely discussed and *** PQCrypto2019, liu, et al. proposed two key recovery attacks against it. However, their first attack heavily relies on a weaken decryption oracle, and the second attack needs to collect about 260ciphertexts from the same message by theoretical analysis, which makes both of the attacks unrealistic. In this paper, inspired by the broadcast attack against NTRU, the authors find out that for NTRURe Encrypt the delegator and the delegatee can efficiently recover each other’s private key in polynomial time without any unrealistic assumptions. In addition, the authors also show how to fix NTRURe Encrypt to resist the proposed attacks. As a by-product, the authors also show how to commit broadcast attacks against NTRU 2001 with even dg, which was thought infeasible before.

关键词： Broadcast attack key recovery NTRU NTRUReEncrypt

Improving the spaceborne GNSS-R altimetric precision based on the novel multilayer feedforward neural network weighted joint prediction model

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 271-284页

作者： Yiwen Zhang Wei zheng Zongqiang liu Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijing 100094China China Academy of Aerospace Science and Innovation Beijing 100176China State Key Laboratory of Space-Ground Integrated Information Technology Beijing Institute of Satellite Information EngineeringBeijing 100194China

Global navigation satellite system-reflection(GNSS-R)sea surface altimetry based on satellite constellation platforms has become a new research direction and inevitable trend,which can meet the altimetric precision at the global scale required for underwater *** present,there are still research gaps for GNSS-R altimetry under this mode,and its altimetric capability cannot be specifically ***,GNSS-R satellite constellations that meet the global altimetry needs to be ***,the matching precision prediction model needs to be established to quantitatively predict the GNSS-R constellation altimetric ***,the GNSS-R constellations altimetric precision under different configuration parameters is calculated,and the mechanism of the influence of orbital altitude,orbital inclination,number of satellites and simulation period on the precision is analyzed,and a new multilayer feedforward neural network weighted joint prediction model is ***,the fit of the prediction model is verified and the performance capability of the model is tested by calculating the R2 value of the model as 0.9972 and the root mean square error(RMSE)as 0.0022,which indicates that the prediction capability of the model is ***,using the novel multilayer feedforward neural network weighted joint prediction model,and considering the research results and realistic costs,it is proposed that when the constellation is set to an orbital altitude of 500 km,orbital inclination of 75and the number of satellites is 6,the altimetry precision can reach 0.0732 m within one year simulation period,which can meet the requirements of underwater navigation precision,and thus can provide a reference basis for subsequent research on spaceborne GNSS-R sea surface altimetry.

关键词： GNSS-R satellite constellations Sea surface altimetric precision Underwater navigation Multilayer feedforward neural network

Experimental and numerical simulation study on the erosion behavior of the elbow of gathering pipeline in shale gas field

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1257-1274页

作者： En-Bin liu Shen Huang Ding-Chao Tian Lai-min Shi Shan-Bi Peng He zheng Petroleum Engineering School Southwest Petroleum UniversityChengdu 610500SichuanChina Chongqing Natural Gas Sales Center Natural Gas BranchSinopecChongqing400023China Zhejiang Zheneng Natural Gas Operation Co. Ltd.Hangzhou 310000ZhejiangChina School of Civil Engineering and Architecture Southwest Petroleum UniversityChengdu 610500SichuanChina Louisiana Tech Univ Trenchless Technol Ctr599 Dan Reneau DrRustonLA71270USA Southwest Oil and Gas Field Branch Natural Gas Research Institute Chengdu 610213SichuanChina

During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUENT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%.

关键词： Shale gas Gas gathering pipeline Elbow Erosion CFD