检索结果-南通市图书馆

A robust vector tracking loop structure based on potential bias analysis

Chinese Journal of Aeronautics 2024年第4期37卷 405-420页

作者： Qiongqiong JIA Yiran LuO Bing Xu Li-ta HSu Renbiao Wu Tianjin Key Lab for Advanced Signal Processing Civil Aviation University of ChinaTianjin 300300China Interdisciplinary Division of Aeronautical and Aviation Engineering The Hong Kong Polytechnic University999077Hong KongChina Department of Geomatics Engineering University of CalgaryCalgary T2N1N4Canada

This paper proposes a robust vector tracking loop structure based on potential bias analysis. The influence of four kinds of biases on the existing two implementations of Vector Tracking Loops(VTLs) is illustrated by theoretical analysis and numerical simulations, and the following findings are obtained. Firstly, the initial user state bias leads to steady navigation solution bias in the relative VTL, while new measurements can eliminate it in the absolute VTL. Secondly, the initial code phase bias is transferred to the following navigation solutions in the relative VTL, while new measurements can eliminate it in the absolute VTL. Thirdly, the user state bias induced by erroneous navigation solution of VTLs can be eliminated by both of the two VTLs. Fourthly,the multipath/NLOS likely affects the two VTLs, and the induced tracking bias in the duration of the multipath/NLOS would decrease the performance of VTLs. Based on the above analysis,a robust VTL structure is proposed, where the absolute VTL is selected for its robustness to the two kinds of initialization biases;meanwhile, the instant bias detection and correction method is used to improve the performance of VTLs in the duration of the multipath/NLOS. Numerical simulations and experimental results verify the effectiveness of the proposed robust VTL structure.

关键词： Global Navigation Satellite System(GNSS) Vector Tracking Loop(VTL) Multipath Non-Line-of-Sight(NLOS) Tracking bias propagation Least Absolute Shrinkage and Selection Operator(LASSO)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Protein-activated atomic layer deposition for robust crude-oil-repellent hierarchical nano-armored membranes

引用

Science Bulletin 2024年第2期69卷 218-226页

作者： Xiaobin Yang Pan Sun Yajie Wen Anil u.mane Jeffrey W.Elam Jun ma Shaomin Liu Seth B.Darling Lu Shao MIIT Key Laboratory of Critical materials Technology for New Energy Conversion and Storage State Key Laboratory of Urban Water Resource and EnvironmentSchool of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001China Chemical Sciences and Engineering Division Argonne National LaboratoryLemont IL 60439USA Applied materials Division Argonne National LaboratoryLemont IL 60439USA Advanced materials for Energy-Water Systems Energy Frontier Research Center Argonne National LaboratoryLemont IL 60439USA Pritzker School of Molecular Engineering University of ChicagoChicago IL 60637USA Department of Physics University of Ilinois at ChicagoChicago IL 60607USA School of Environment Harbin Institute of TechnologyHarbin 150090China WA School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerth WA 6845Australia

Atomic layer deposition(ALD)offers unique capabilities to fabricate atomically engineered porous materials with precise pore tuning and multi-functionalization for diverse applications like advanced membrane separations towards sustainable energy-water ***,current ALD technique is inhibited on most non-polar polymeric membranes due to lack of accessible nucleation ***,we report a facile method to efficiently promote ALD coating on hydrophobic surface of polymeric membranes via novel protein activation/*** a proof of concept,TiO2 ALD-coated membranes activated by bovine serum albumin exhibit remarkable superhydrophilicity,ultralow underwater crude oil adhesion,and robust tolerance to rigorous environments including acid,alkali,saline,and *** importantly,excellent cyclable crude oil-in-water emulsion separation performance can be *** mechanism for activation/sensitization is rooted in reactivity for a particular set of amino ***,the universality of protein-sensitized ALD is demonstrated using common egg white,promising numerous potential usages in biomedical engineering,environmental remediation,lowcarbon manufacturing,catalysis,and beyond.

关键词： Membrane separation Atomic layer deposition Water treatment Antifouling

来源：

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

Damping Characteristic Analysis and Optimization of Wind-thermal-bundled Power Transmission by LCC-HVDC Systems

引用

Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 299-312页

作者： Liwen Zheng Shiying ma the Power System Department China Electric Power Research InstituteBeijing 100192China

With the rapid development of renewable energy,wind-thermal-bundled power transmission by line-commutated converter based high-voltage direct current(LCC-HVDC)systems has been widely *** dynamic interaction mechanisms among permanent magnet synchronous generators(PMSGs),synchronous generators(SGs),and LCC-HVDC system become *** deal with this issue,a path analysis method(PAM)is proposed to study the dynamic interaction mechanism,and the damping reconstruction is used to analyze the damping characteristic of the ***,based on the modular modeling,linearized models for the PMSG subsystem,the LCC-HVDC subsystem,and the SG subsystem are ***,based on the closed-loop transfer function diagram of the system,the disturbance transfer path and coupling relationship among subsystems are analyzed by the PAM,and the damping characteristic analysis of the SG-dominated oscillation mode is studied based on the damping *** with the PAM,the small-signal model of the system is obtained and eigenvalue analysis results are ***,the effect of the control parameters on the damping characteristic is analyzed and the conclusions are verified by time-domain ***,the penalty functions of the oscillation modes and decay modes are taken as the objective function,and an optimization strategy based on the Monte Carlo method is proposed to solve the parameter optimization *** simulation results are presented to validate the effectiveness of the proposed strategy.

关键词： Wind-thermal-bundled power transmission line-commutated converter based high-voltage direct current(LCC-HVDC) path analysis method(PAM) damping characteristic analysis Monte Carlo method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mitigate noisy data for smart IoT via GAN based machine unlearning

引用

Science China(Information Sciences) 2024年第3期67卷 62-78页

作者： Zhuo ma Yilong YANG Yang LIu Xinjing LIu Jianfeng ma School of Cyber Engineering Xidian University State Key Laboratory of Integrated Services Networks (ISN)

With the development of IoT applications, machine learning dramatically improves the utility of variable IoT systems such as autonomous driving. Although the pretrain-finetune framework can cope well with data heterogeneity in complex IoT scenarios, the data collected by sensors often contain unexpected noisy data, e.g., out-of-distribution(OOD) data, which leads to the reduced performance of fine-tuned models. To resolve the problem, this paper proposes Mu GAN, a method that can mitigate the side-effect of OOD data via the generative adversarial network(GAN)-based machine unlearning. Mu GAN follows a straightforward but effective idea to mitigate the performance loss caused by OOD data, i.e., “flashbacking” the model to the condition where OOD data.a.e excluded from model training. To achieve the goal, we design an adversarial game, where a discriminator is trained to identify whether a sample belongs to the training set by observing the confidence score. Meanwhile, a generator(i.e., the target model) is updated to fool the discriminator into believing that the OOD data.a.e not included in the training set but others do. The experimental results show that benefiting from the high unlearning rate(more than 90%) and retention rate(99%), Mu GAN succeeds in lowering the model performance degradation caused by OOD data from 5.88% to 0.8%.

关键词： machine unlearning generative adversarial network out of distribution data Internet of Thing neural network

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Effect of heat treatment on the microstructure,mechanical properties and fracture behaviors of ultra-high-strength SiC/Al-Zn-Mg-Cu composites

引用

International Journal of Minerals,Metallurgy and materials 2024年第10期31卷 2233-2243页

作者： Guonan ma Shize Zhu Dong Wang Peng Xue BolüXiao Zongyi ma Shi-changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Centre of Excellence for Advanced materials Dongguan 523808China

A high-zinc composite,12vol%SiC/Al-13.3 Zn-3.27 Mg-1.07Cu(wt%),with an ultra-high-strength of 781 MPa was success-fully fabricated through a powder metallurgy method,followed by an extrusion *** effects of solid-solution and aging heat treat-ments on the microstructure and mechanical properties of the composite were extensively *** with a single-stage sol-id-solution treatment,a two-stage solid-solution treatment(470℃/1 h+480℃/1 h)exhibited a more effective solid-solution strengthen-ing owing to the higher degree of solid-solution and a more uniform *** to the aging hardness curves of the com-posite,the optimized aging parameter(100℃/22 h)was *** the aging temperature and time resulted in finer and more uniform nanoscale precipitates but only yielded a marginal increase in tensile *** fractography analysis revealed that intergranu-lar cracking and interface debonding were the main fracture mechanisms in the ultra-high-strength SiC/Al-Zn-Mg-Cu *** regions,such as the SiC/Al interface containing numerous compounds and the precipitate-free zones at the high-angle grain boundaries,were identified as significant factors limiting the strength enhancement of the *** compounds,including MgO,MgZn2,and Cu5Zn8,reduced the interfacial bonding strength,leading to interfacial debonding.

关键词： metal matrix composites heat treatment interfacial reaction mechanical properties fracture mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CoDetect: cooperative anomaly detection with privacy protection towards uAV swarm

引用

Science China(Information Sciences) 2024年第5期67卷 325-326页

作者： Teng LI Weiguo LIN Ruichen ma Zhuo ma Yulong SHEN Jianfeng ma School of Cyber Engineering Xidian University School of Computer Science and Technology Xidian University

As mission scenarios grow more complex, the role of a single unmanned aerial vehicle(uAV) is limited. The uAV swarm,surpassing the single uAV, dynamically establishes temporary communication networks, ensuring high transmission rates and expansive communication coverage [1]. unlike a single uAV, a swarm faces increased security risks, requiring specific capabilities.(1) Anomalies detection.

关键词： unmanned aerial vehicles (uAV)

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Two-stage aging treatment to accelerate aging kinetics without impairing strength in B_4C/7A04Al composite

引用

Science China(Technological Sciences) 2024年第8期67卷 2485-2492页

作者： CHEN Yuntao ma GuoNan ZHu ShiZe WANG Dong XIAO BoLv ma ZongYi Shi-Changxu Innovation Center for Advanced materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Centre of Excellence for Advanced materials Dongguan 523808China

Aging treatments are the key process to obtain satisfactory strength for 7xxxAl alloys and their composites. However, traditional single-stage(SS) aging is time-consuming to reach a peak strength condition. In this study, an efficient 120℃ + 160℃ two-stage(TS) aging treatment was proposed on a B_4C/7A04Al composite fabricated via powder metallurgy(PM) technology, which could acquire similar peak-aging strength but only took about 15% of the time compared to traditional 120℃ SS aging. The evolution of precipitation during the TS aging was investigated, as well as those of the 7A04Al alloys for comparison. In the second stage aging process, the higher aging temperature accelerated the nucleation of η′ phases inside the grains and thus increased the density of precipitates. Moreover, the short aging time limited the coarsening of precipitates and the broadening of precipitatefree zones. The above factors were beneficial for quickly obtaining satisfactory precipitation strengthening effects. The B_4C/7A04Al composite exhibited slower aging kinetics than the 7A04Al alloy in the TS aging. Mg elements consumption by the chemical reaction between B impurities introduced by B_4C particles and the Al matrix was considered to potentially retard the aging kinetics of the B_4C/7A04Al composite. Nevertheless, the precipitation sequence was not affected.

关键词： aluminum matrix composites aging treatment powder metallurgy mechanical properties precipitation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Artificial intelligence-driven radiomics study in cancer:the role of feature engineering and modeling

引用

Military Medical Research 2024年第1期11卷 115-147页

作者： Yuan-Peng Zhang Xin-Yun Zhang Yu-Ting Cheng Bing Li Xin-Zhi Teng Jiang Zhang Saikit Lam ta Zhou Zong-Rui ma Jia-Bao Sheng Victor CWtam Shara WYLee Hong Ge Jing Cai Department of Medical Informatics Nantong UniversityNantong 226001JiangsuChina Department of Health Technology and Informatics the Hong Kong Polytechnic UniversityHong Kong 999077China The Hong Kong Polytechnic university Shenzhen Research Institute Shenzhen 518000GuangdongChina Department of Radiation Oncology the Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer HospitalZhengzhou 450008China

Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’***,the interpretation of medical images can be highly subjective and dependent on the expertise of ***,some potentially useful quantitative information in medical images,especially that which is not visible to the naked eye,is often ignored during clinical *** contrast,radiomics performs high-throughput feature extraction from medical images,which enables quantitative analysis of medical images and prediction of various clinical *** have reported that radiomics exhibits promising performance in diagnosis and predicting treatment responses and prognosis,demonstrating its potential to be a non-invasive auxiliary tool for personalized ***,radiomics remains in a developmental phase as numerous technical challenges have yet to be solved,especially in feature engineering and statistical *** this review,we introduce the current utility of radiomics by summarizing research on its application in the diagnosis,prognosis,and prediction of treatment responses in patients with *** focus on machine learning approaches,for feature extraction and selection during feature engineering and for imbalanced datasets and multi-modality fusion during statistical ***,we introduce the stability,reproducibility,and interpretability of features,and the generalizability and interpretability of ***,we offer possible solutions to current challenges in radiomics research.

关键词： Artificial intelligence Radiomics Feature extraction Feature selection Modeling Interpretability Multimodalities Head and neck cancer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Review on Vibration Control of Multiple Cylinders Subjected to FlowInduced Vibrations

引用

China Ocean Engineering 2024年第2期38卷 183-197页

作者： Xu Wan-hai ma Ye-xuan State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin UniversityTianjin 300350China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China

The fatigue damage caused by flow-induced vibration(FIV)is one of the major concerns for multiple cylindrical structures in many engineering *** FIV suppression is of great importance for the security of many cylindrical *** active and passive control methods have been employed for the vibration suppression of an isolated cylinder undergoing vortex-induced vibrations(VIV).The FIV suppression methods are mainly extended to the multiple cylinders from the vibration control of the isolated *** to the mutual interference between the multiple cylinders,the FIV mechanism is more complex than the VIV mechanism,which makes a great challenge for the FIV *** efforts have been devoted to vibration suppression of multiple cylinder systems undergoing FIV over the past two *** control methods,such as helical strakes,splitter plates,control rods and flexible sheets,are not always effective,depending on many influence factors,such as the spacing ratio,the arrangement geometrical shape,the flow velocity and the parameters of the vibration control *** FIV response,hydrodynamic features and wake patterns of the multiple cylinders equipped with vibration control devices are reviewed and *** FIV suppression efficiency of the vibration control methods are analyzed and compared considering different influence *** research on the FIV suppression of multiple cylinders is suggested to provide insight for the development of FIV control methods and promote engineering applications of FIV control methods.

关键词： flow-induced vibration vibration control multiple cylinders tandem side-by-side staggered

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Partial regularity and nonlinear potential estimates for Stokes systems with super-quadratic growth

引用

Science China mathematics 2024年第7期67卷 1525-1554页

作者： Lingwei ma Zhenqiu Zhang School of mathematical Sciences Tianjin Normal UniversityTianjin300387China School of mathematical Sciences and LPMC Nankai UniversityTianjin300071China

This paper builds a bridge between partial regularity theory and nonlinear potential theory for the following generalized stationary Stokes system with super-quadratic growth and continuous coefficients:-div A(x,Du)+■π=f,div u=0,where Du is the symmetric part of the gradient■*** first establish anε-regularity criterion involving both the excess functional of the symmetric gradient Du and Wolff potentials of the nonhomogeneous term f to guarantee the local vanishing mean oscillation(VMO)-regularity of Du in an open subset Ω_(u) of Ω with full *** anε-regularity criterion leads to a pointwise Wolff potential estimate of Du,which immediately infers that Du is partially C^(0)-regular under appropriate ***,we give a local continuous modulus estimate of Du.

关键词： nonlinear Stokes system partial regularity Wolff potential estimates continuous modulus estimates

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：