检索结果-南通市图书馆

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

异常值干扰下的加权中值截取相位检索算法

宇航总体技术 2024年第3期8卷 44-49页

作者：李晓东刘冠男付宁乔立岩哈尔滨工业大学电子与信息工程学院哈尔滨150001 北京宇航系统工程研究所北京100076

在航天领域的许多测量场景中,信号的相位信息容易遭到破坏。本文旨在解决有异常值干扰的相位检索问题。中值可以对抗异常值,故常作为正则化标准截取无相测量值,这会导致可用测量值的减少,从而提高测量复杂度。为克服这一难点,进行加权处... 详细信息

在航天领域的许多测量场景中,信号的相位信息容易遭到破坏。本文旨在解决有异常值干扰的相位检索问题。中值可以对抗异常值,故常作为正则化标准截取无相测量值,这会导致可用测量值的减少,从而提高测量复杂度。为克服这一难点,进行加权处理,提出了加权中值截取算法,利用可以表征指向原信号概率的权值进一步挖掘了未被截取测量值的可用信息,与同类算法相比,在测量复杂度和对抗异常值干扰方面更为优越。

关键词：相位检索异常值中值截取

Fractional Envelope Analysis for Rolling Element Bearing Weak Fault Feature Extraction

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2017年第2期4卷 353-360页

作者： Jianhong Wang liyan qiao Yongqiang Ye YangQuan Chen School of Science Nantong University School of Engineering University of California IEEE College of Automation Engineering Nanjing University of Aeronautics and Astronautics

The bearing weak fault feature extraction is crucial to mechanical fault diagnosis and machine condition monitoring. Envelope analysis based on Hilbert transform has been widely used in bearing fault feature extraction. A generalization of the Hilbert transform, the fractional Hilbert transform is defined in the frequency domain, it is based upon the modification of spatial filter with a fractional parameter, and it can be used to construct a new kind of fractional analytic signal. By performing spectrum analysis on the fractional envelope signal, the fractional envelope spectrum can be obtained. When weak faults occur in a bearing, some of the characteristic frequencies will clearly appear in the fractional envelope spectrum. These characteristic frequencies can be used for bearing weak fault feature extraction. The effectiveness of the proposed method is verified through simulation signal and experiment data. © 2017 Chinese Association of Automation.

关键词： Bearings (machine parts) Condition monitoring Extraction Fault detection Feature extraction Frequency domain analysis Hilbert spaces Mathematical transformations Spectrum analysis

A Computer-Aided System for Ocular Myasthenia Gravis Diagnosis

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2021年第5期26卷 749-758页

作者： Guanjie Liu Yan Wei Yunshen Xie Jianqiang Li liyan qiao Ji-jiang Yang the Faculty of Information Technology Beijing University of TechnologyBeijing 100124China the Neurology Department The Second Affiliated Hospital of Tsinghua UniversityBeijing 100040China the Department of Automation Tsinghua UniversityBeijing 100084China

The current mode of clinical aided diagnosis of Ocular Myasthenia Gravis(OMG)is time-consuming and laborious,and it lacks quantitative *** aided diagnostic system for OMG is proposed to solve this *** values calculated by the system include three clinical indicators:eyelid distance,sclera distance,and palpebra superior fatigability test *** the first two indicators,the semantic segmentation method was used to extract the pathological features of the patient's eye image and a semantic segmentation model was *** patient eye image was divided into three regions:iris,sclera,and *** indicators were calculated based on the position of the pixels in the segmentation *** the last indicator,a calculation method based on the Eyelid Aspect Ratio(EAR)is proposed;this method can better reflect the change of eyelid distance over *** system was evaluated based on the collected patient *** results show that the segmentation model achieves a mean Intersection-Over-Union(mIoU)value of 86.05%.The paired-sample T-test was used to compare the results obtained by the system and doctors,and the p values were all greater than ***,the system can reduce the cost of clinical diagnosis and has high application value.

关键词： ocular myasthenia gravis computer-aided system semantic segmentation eyelid aspect ratio

A visible-light-assisted Pd/TiO_(2)gas sensor with carbon nanotubes electrodes for trace formaldehyde detection

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第1期43卷 257-266页

作者： Can Liu qiao-qiao Zou Bin Liu Yong Zhang School of Physics and Optoelectronics Xiangtan UniversityXiangtan 411105China Hunan Institute of Advanced Sensing and Information Technology Xiangtan UniversityXiangtan 411105China School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China

Owing to the ppb-level detection standard toward the toxic and harmful gas,the detection of trace gases has become an important subject in the field of indoor environment ***,the traditional resistive gas sensors hardly meet the requirement due to the weak signal generated by trace gas molecules that are difficult to ***,a visible-light-assisted Pd/TiO_(2)gas sensor is proposed to endow the effective detection of trace formaldehyde(HCHO)gas without heating *** from the enhanced photocatalytic properties of TiO_(2)by Pd decoration,the visible-light-assisted Pd/TiO_(2)gas sensor can detect the HCHO gas as low as80×10^(–9)at room *** successful preparation of nanoscale TiO_(2)sensing layer is facilitated by the ultrathin carbon nanotube interdigital electrode in the gas sensor,which avoids the discontinuity of the sensing layer caused by the excessive thickness of the traditional metal *** addition,the whole preparation process of the Pd/TiO_(2)gas sensor with carbon nanotube electrodes is compatible with mainstream CMOS fabrication technology,which is expected to realize the batch fabrication and micro-integrated application of gas *** is expected that our work can provide a new strategy for the batch preparation of high-performance trace HCHO gas sensors and their future applications in portable electronic devices such as smartphones.

关键词： Visible-light-assisted gas sensor Pd/TiO_(2) Trace HCHO detection Carbon nanotubes electrodes

Evaluation of antibody responses in healthy individuals receiving SARS-CoV-2 inactivated vaccines

在线全文

学校读者我要写书评

暂无评论

Biosafety and Health 2024年第3期6卷 153-164页

作者： Ziyu Liu liyan Cai Man Xing Nan qiao Jiaojiao Liu Xuejun Li Chiyu Zhang Naijun Tang Zhelong Xu Yingying Guo Renfei Lu Dongming Zhou Department of Pathogen Biology School of Basic Medical SciencesTianjin Medical UniversityTianjin 300070China Physical examination center Affiliated Nantong Hospital 3 of Nantong UniversityNantong 226000China Shanghai Public Health Clinical Center Fudan UniversityShanghai 201508China Department of Occupational and Environmental Health School of Public HealthTianjin Medical UniversityTianjin 300070China Clinical Laboratory Affiliated Nantong Hospital 3 of Nantong UniversityNantong 226000China

Inactivated coronavirus disease 2019(COVID-19)vaccines such as CoronaVac and BBIBP-CorV have been widely used in ***,more investigation is still needed to understand antibodies'duration and effectiveness against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants in the real *** this study,575 participants who had been vaccinated with two or three doses of the inactivated vaccine were *** samples were collected and tested for anti-spike IgG and neutralizing antibodies against SARS-CoV-2(original strain,Dela,and Omicron).Unsurprisingly,a third dose of the vaccine significantly enhanced antibody responses against SARS-CoV-2 and its ***,despite a booster dose,the neutralizing antibody levels against Omicron,particularly the BA.5.2 subvariant,remained *** was no sex bias,but an age bias was ***,the predominant IgG subclass antibodies were IgG1 and IgG2,with a much lower level of *** the booster shot,the ratio of IgG4 to IgG1 significantly *** observation of IgG1 to the IgG4 class switch after repeated inactivated vaccinations underscores the importance of continuous monitoring of subclass antibody *** clinical investigations are required to understand the implications of this class switch for optimizing immunization strategies.

关键词： Variant of concern(VOC) Inactivated vaccines Serological study IgG subclasses Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)

Data-Driven Direct Adaptive Risk-Sensitive Control of Stochastic Systems

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4期37卷 1446-1469页

作者： qiao Nan LI Tao School of Mathematical Sciences East China Normal UniversityShanghai 200241China Shanghai Key Laboratory of Pure Mathematics and Mathematical Practice School of Mathematical SciencesEast China Normal UniversityShanghai 200241China

The authors propose a data-driven direct adaptive control law based on the adaptive dynamic programming(ADP) algorithm for continuous-time stochastic linear systems with partially unknown system dynamics and infinite horizon quadratic risk-sensitive *** authors use online data of the system to iteratively solve the generalized algebraic Riccati equation(GARE) and to learn the optimal control law *** the case with measurable system noises,the authors show that the adaptive control law approximates the optimal control law as time goes *** the case with unmeasurable system noises,the authors use the least-square solution calculated only from the measurable data instead of the real solution of the regression equation to iteratively solve the *** authors also study the influences of the intensity of the system noises,the intensity of the exploration noises,the initial iterative matrix,and the sampling period on the convergence of the ADP ***,the authors present two numerical simulation examples to demonstrate the effectiveness of the proposed algorithms.

关键词： Adaptive dynamic programming direct adaptive control generalized algebraic Riccati equation risk-sensitive control

ROS-responsive hydrogels with spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs for the repair of MRSA-infected wounds

在线全文

学校读者我要写书评

暂无评论

Regenerative Biomaterials 2024年第1期3卷 119-131页

作者： Bowen qiao Jiaxin Wang Lipeng qiao Aziz Maleki Yongping Liang Baolin Guo Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research College of StomatologyXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory for Mechanical Behavior of Materials Frontier Institute of Science and TechnologyXi’an Jiaotong UniversityXi’an 710049China Zanjan Pharmaceutical Nanotechnology Research Center(ZPNRC) Zanjan 45139-56184Iran Department of Orthopaedics The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061People’s Republic of China

For the treatment of MRSA-infected wounds,the spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs is a promising *** this study,ROS-responsive HA-PBA/PVA(HPA)hydrogel was prepared by phenylborate ester bond cross-linking between hyaluronic acid-grafted 3-amino phenylboronic acid(HA-PBA)and polyvinyl alcohol(PVA)to achieve spatiotemporally controlled release of two kinds of drug to treat MRSA-infected *** hydrophilic antibiotic moxifloxacin(M)was directly loaded in the *** hydrophobic curcumin(Cur)with anti-inflammatory function was first mixed with Pluronic F127(PF)to form Cur-encapsulated PF micelles(Cur-PF),and then loaded into the HPA *** to the different hydrophilic and hydrophobic nature of moxifloxacin and Cur and their different existing forms in the HPA hydrogel,the final HPA/M&Cur-PF hydrogel can achieve different spatiotemporally sequential delivery of the two *** addition,the swelling,degradation,self-healing,antibacterial,anti-inflammatory,antioxidant property,and biocompatibility of hydrogels were ***,in the MRSA-infected mouse skin wound,the hydrogel-treated group showed faster wound closure,less inflammation and more collagen *** experiments further confirmed that the hydrogel promoted better repair by reducing inflammation(TNF-a)and promoting vascular(VEGF)*** conclusion,this HPA/M&CurPF hydrogel that can spatiotemporally sequential deliver antibacterial and anti-inflammatory drugs showed great potential for the repair of MRSA-infected skin wounds.

关键词： MRSA-infected wounds spatiotemporally sequential delivery antibacterial anti-inflammatory

基于有限新息率的非瞬时扩散点源参数估计方法

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

电子与信息学报 2022年第8期44卷 2739-2748页

作者：付宁沈孟垚尉志良乔立岩哈尔滨工业大学电子与信息工程学院哈尔滨150001

扩散现象在农业真菌传播、大气污染等现实场景广泛存在,扩散源参数估计也因此在农业、工业等实际应用中具有重要意义。目前针对扩散源参数估计提出的方法大多针对理想的瞬时点源信号,对于非瞬时的实际扩散过程存在模型失配问题,极大地... 详细信息

扩散现象在农业真菌传播、大气污染等现实场景广泛存在,扩散源参数估计也因此在农业、工业等实际应用中具有重要意义。目前针对扩散源参数估计提出的方法大多针对理想的瞬时点源信号,对于非瞬时的实际扩散过程存在模型失配问题,极大地限制了算法的实际应用场景。为了解决模型不匹配的问题,同时有效估计扩散源持续时间参数,该文将扩散源信号模型拓展为脉宽可变信号,并提出相应的非瞬时点源模型的参数估计算法。该算法中,利用无线传感网络采样得到实际测量值,找到一个组合系数将实际测量值线性组合为指数函数,再根据有限新息率(FRI)采样理论对组合后的数据用零化滤波器方法求解扩散源参数。仿真结果表明,在信噪比20 dB,位置参数重构MAE能够达到0.008左右,脉宽参数能够达到0.1左右,持续时间参数能够达到0.05左右,这验证了非瞬时点源参数估计的准确性。同时我们分析了传感器个数等因素对参数恢复性能的影响。

关键词：扩散源参数估计有限新息率脉宽可变脉冲

The spectrum and stability of travelling pulses in a coupled FitzHugh-Nagumo equation

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第5期67卷 975-1010页

作者： Qi qiao Xiang Zhang School of Mathematical Sciences Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Scientific and Engineering Computing(Ministry of Education) and Shanghai Frontier Science Center of Modern Analysis(CMA-Shanghai)Shanghai Jiao Tong UniversityShanghai 200240China

For a coupled slow-fast FitzHugh-Nagumo(FHN)equation derived from a reaction-diffusionmechanics(RDM)model,Holzer et al.(2013)studied the existence and stability of the travelling pulse,which consists of two fast orbit arcs and two slow ones,where one fast segment passes the unique fold point with algebraic decreasing and two slow ones follow normally hyperbolic critical curve *** and Zhang(2021)obtained the existence of the travelling pulse,whose two fast orbit arcs both exponentially decrease,and one of the slow orbit arcs could be normally hyperbolic or not at the ***,we characterize both the nonlinear and spectral stability of this travelling pulse.

关键词： coupled FitzHugh-Nagumo equation singular perturbation travelling pulse spectrum nonlinear stability spectral stability