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Vessel fusion tracking with a dual-frequency high-frequency surface wave radar and calibrated by an automatic identification system

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Acta Oceanologica Sinica 2018年第7期37卷 131-140页

作者： ZHANG Hui liu yongxin JI Yonggang WANG Linglin College of Computer Science Inner Mongolia University Hohhot 010021 China College of Electronic Information Engineering Inner Mongolia University Hohhot 010021 China The First Institute of Oceanography State Oceanic Administration Qingdao 266061 China

High-frequency surface wave radar（HFSWR） and automatic identification system（AIS） are the two most important sensors used for vessel *** HFSWR can be applied to tracking all vessels in a detection area,while the AIS is usually used to verify the information of cooperative *** of interference from sea clutter,employing single-frequency HFSWR for vessel tracking may obscure vessels located in the blind zones of Bragg *** changes in the detection frequencies constitutes an effective method for addressing this deficiency.A solution consisting of vessel fusion tracking is proposed using dual-frequency HFSWR data calibrated by the *** different systematic biases exist between HFSWR frequency measurements and AIS measurements,AIS information is used to estimate and correct the HFSWR systematic biases at each ***,AIS point measurements for cooperative vessels are associated with the HFSWR measurements using a JVC assignment *** the association results of the cooperative vessels,the systematic biases in the dualfrequency HFSWR data are estimated and ***,based on the corrected dual-frequency HFSWR data,the vessels are tracked using a dual-frequency fusion joint probabilistic data association（JPDA）-unscented Kalman filter（UKF） *** results using real-life detection data show that the proposed method is efficient at tracking vessels in real time and can improve the tracking capability and accuracy compared with tracking processes involving single-frequency data.

关键词： vessel tracking high-frequency surface wave radar automatic identification system joint probabilistic data association unscented Kalman filter

Calculation of electric field effects on the Gibbs free energy of the Al-Li-Mg alloy

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Rare Metals 2007年第5期26卷 508-514页

作者： ZHANG Jianjun CHEN Zheng WANG yongxin liu Bing LI Yongsheng School of Materials Science and Engineering Northwestern Polytechnical University Xi＇an 710072 China

Based on the Thomas-Fermi model,the calculation methods of the monatomic Gibbs free energy were found. The interior potential boundary condition under electric field was defined. The calculation methods of Gibbs free energy for the monatomic,compound,and solid solution with electric field were set up. Under the influence of electric field,the Gibbs free energy of Al is the most sensitive,followed by those of Li and Mg. At the solution temperature the Gibbs free energies of Al3Li and its elements under electric field are not symmetrical about the zero point of electric field,whereas at the aging temperature their values are symmetrical about the zero point of electric field. At the solution temperature near the zero point of electric field,the Gibbs free energy of Al3Li is higher than that of Al-2.14%Li. And at 460 K the Gibbs free energy of Al3Li is lower than that of Al-2.14wt.%Li under electric field. The Gibbs free energy of 1420 alloy decreases from both sides of electric field to the zero point at the aging temperature.

关键词： Al-Li-Mg alloy thermodynamics parameters Thomas-Fermi model electric field

Pilot Domain NOMA for Grant-Free Massive Random Access in Massive MIMO Marine Communication System

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China Communications 2020年第6期17卷 131-144页

作者： yongxin liu Ming Zhao Limin Xiao Shidong Zhou Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Tsinghua National Laboratory for Information Science and Technology Tsinghua UniversityBeijing 100084China

We propose a pilot domain non-orthogonal multiple access(NOMA)for uplink massive devices grant-free random access scenarios in massive multiple-input multiple-output(MIMO)maritime communication *** scenarios are characterized by numerous devices with sporadic access behavior,and therefore only a subset of them are *** to massive potential devices in the network,it is infeasible to assign a unique orthogonal pilot to each device in *** such scenarios,pilot decontamination is a crucial *** this paper,the devices are randomly assigned non-orthogonal pilots which are constructed by a linear combination of some orthogonal *** show that a bipartite graph can conveniently describe the interference cancellation(IC)processes of pilot *** spectrum efficiency(SE)and low outage probability can be obtained by selecting the numbers of orthogonal pilots according to the given probability *** evaluatioDs show that the proposed pilot domain NOMA decreases the outage probability from 20%to 2 e-12 at the SE of 4 bits/s/Hz for a single device,compared to the conventional method of slotted ALOHA with 1024 antennas at the BS,or increases the spectrum efficiency from 1.2 bits/s/Hz to 4 bit/s/Hz at the outage probability of2 e-12 in contrast with the Welch bound equality(WBE)non-orthogonal pilots.

关键词： NOMA grant-free random access maritime-communication bipartite graphs density evolution

Estimating significant wave height from SAR imagery based on an SVM regression model

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Acta Oceanologica Sinica 2018年第3期37卷 103-110页

作者： GAO Dong liu yongxin MENG Junmin JIA Yongjun FAN Chenqing College of Electronic and Information Engineering Inner Mongolia University The First Institute of Oceanography State Oceanic Administration National Satellite Ocean Application Service State Oceanic Administration

A new method for estimating significant wave height（SWH） from advanced synthetic aperture radar（ASAR） wave mode data based on a support vector machine（SVM） regression model is presented. The model is established based on a nonlinear relationship between σ0, the variance of the normalized SAR image, SAR image spectrum spectral decomposition parameters and ocean wave SWH. The feature parameters of the SAR images are the input parameters of the SVM regression model, and the SWH provided by the European Centre for Medium-range Weather Forecasts（ECMWF） is the output parameter. On the basis of ASAR matching data set, a particle swarm optimization（PSO） algorithm is used to optimize the input kernel parameters of the SVM regression model and to establish the SVM model. The SWH estimation results yielded by this model are compared with the ECMWF reanalysis data and the buoy data. The RMSE values of the SWH are 0.34 and 0.48 m, and the correlation coefficient is 0.94 and 0.81, respectively. The results show that the SVM regression model is an effective method for estimating the SWH from the SAR data. The advantage of this model is that SAR data may serve as an independent data source for retrieving the SWH, which can avoid the complicated solution process associated with wave spectra.

关键词： advanced synthetic aperture radar wave mode support vector machine significant wave height

Threshold of Perception for Capacitor Discharge on the Human Body

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Threshold of Perception for Capacitor Discharge on the Human...

Ultrathin metal-organic framework nanosheets (Cu-TCPP)-based isothermal nucleic acid amplification for food allergen detection

1997 International Symposium on Electromagnetic Compatibility

作者： liu yongxin Wu Zhancheng liu Shanghe Quartermaster Facilities Institute Electrostatic Institute Ordnance Engineering College

ISBN: (纸本)0780336089

＜正＞Study reports about capacitor discharge on the human body are *** show that the capacitor value has great effect on the threshold voltage:when the value is small. threshold voltage of person is very different from each other,this differences become smaller and smaller when the capacitor value *** paper also reports the charge and the power of *** formula about the charge and the capacitor is also presented.

关键词： Capacitor discharge perception threshold

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Food Science and Human Wellness 2023年第5期12卷 1788-1798页

作者： Jiale Gao Xiaodong Sun yongxin liu Bing Niu Qin Chen Xueen Fang Shanghai Key Laboratory of Bio-Energy Crops School of Life SciencesShanghai UniversityShanghai 200444China Shanghai Engineering Research Center of Organ Repair School of MedicineShanghai UniversityShanghai 200444China Department of Chemistry and Institutes of Biomedical Sciences Fudan UniversityShanghai 200433China

The rapid and accurate detection of peanuts and soybeans allergen is important to the food safety. In this study, Cu-TCPP nanosheet, a kind of ultra-thin metal-organic framework(MOF)was synthesized and applied in loop-mediated isothermal amplification(named Cu-TCPP@LAMP), which can inhibit the non-specific amplification by absorbing and precise temperature releasing of single primer. As thus, Cu-TCPP@LAMP can achieve high sensitivity and specific amplification of the target gene. As a result, peanut and soybean allergens genes contained in food were successfully detected with a favorable detection sensitivity(5 ng/μL for peanuts and 10 ng/μL for soybeans)and reliable repeatability(The coefficient of variation was 3.38% for peanuts and 3.33% for soybeans). Moreover, the established method was utilized for detection of several commercial products, and had a high consistency with the standard method. Apart from food allergens, this novel assay can be widely used in other areas, such as pathogen detection, tumor nucleic acid detection and so on.

关键词： Cu-TCPP nanosheet Plant allergen Nucleic acid detection Loop-mediated isothermal amplification

The influence of air supply inlet location on the spatial-temporal distribution of bioaerosol in isolation ward under three mixed ventilation modes

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Energy and Built Environment 2023年第4期4卷 445-457页

作者： Zhijian liu Tianci Wang yongxin Wang Haiyang liu Guoqing Cao Song Tang Department of Power Engineering North China Electric Power UniversityBaodingHebei 071003China Institute of Building Environment and Energy China Academy of Building ResearchBeijing 100013China China CDC Key Laboratory of Environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijing 100021China

The outbreak of COVID-19 and the spread of infectious pathogens through bioaerosols have once again aroused widespread concern *** ward is an important place to prevent the spread of infectious ***,infection of health care workers(HCWs)in the isolation ward often occurs,so it is ur-gent to carry out relevant research to reduce the cross-infection between HCWs and *** this paper,the temporal and spatial distribution characteristics of bioaerosols under three mixed ventilation modes in a single ward were studied,namely,upper supply side return air of Case 1 and side supply and side return ventilation are Case 2 and Case 3 *** results show that the removal efficiency of bioaerosol in the ventilation mode of Case 3,in which directional airflow is formed from the air supply inlet to the release source and then to the exhaust outlet,is 46.6%and 67.7%higher than that of Case 1 and Case 2,*** addition,ventilation methods based on mixed theory do not guarantee good air quality in the breathing zone(1.3 m to 1.7 m)of HCWs,which may increase the inhalation risk for *** is hoped that our results can provide some useful suggestions for optimizing the airflow layout of the isolation ward,reducing the risk of cross-infection,and virus elimination.

关键词： Bioaerosol Isolation ward Mixed ventilation Breathing zone Computational fluid dynamics

Paradigm of Numerical Simulation of SpatialWind Field for Disaster Prevention of Transmission Tower Lines

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Structural Durability & Health Monitoring 2023年第6期17卷 521-539页

作者： yongxin liu Puyu Zhao Jianxin Xu Xiaokai Meng Hong Yang Bo He Electric Power Research Institute State Grid Shanxi Electric Power CompanyTaiyuan030001China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an710049China

Numerical simulation of the spatial wind field plays a very important role in the study of wind-induced response law of transmission tower structures.A reasonable construction of a numerical simulation method of the wind field is conducive to the study of wind-induced response law under the action of an actual wind ***,many research studies rely on simulating spatial wind fields as Gaussian wind,often overlooking the basic non-Gaussian *** paper aims to provide a comprehensive overview of the historical development and current state of spatial wind field simulations,along with a detailed introduction to standard simulation ***,it delves into the composition and unique characteristics of spatial *** process of fluctuating wind simulation based on the linear filter AR method is improved by introducing spatial correlation and non-Gaussian distribution *** numerical simulation method of the wind field is verified by taking the actual transmission tower as a calculation *** results show that the method summarized in this paper has a broader application range and can effectively simulate the actual spatial wind field under various conditions,which provides a valuable data basis for the subsequent research on the wind-induced response of transmission tower lines.

关键词： Wind speed time series numerical simulation linear filter method non-Gaussian

Magnetic probe diagnostics of nonlinear standing waves and bulk ohmic electron power absorption in capacitive discharges

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Plasma Science and Technology 2021年第11期23卷 74-83页

作者： Kai ZHAO yongxin liu Quanzhi ZHANG Demetre J ECONOMOU Younian WANG Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024People's Republic of China Plasma Processing Laboratory William A.Brookshire Department of Chemical and Biomolecular EngineeringUniversity of HoustonHoustonTexas 77204-4004United States of America

It is recognized that standing wave effects appearing in large-area,very-high-frequency capacitively coupled plasma(CCP)reactors cause center-high plasma *** a high-frequency magnetic probe,we present a direct experimental diagnostic of the nonlinear standing waves and bulk ohmic electron power absorption dynamics in low pressure CCP discharges for different driving frequencies of 13.56,30,and 60 *** design,principle,calibration,and validation of the probe are described in *** structures of the harmonics of the magnetic field,determined by the magnetic probe,were used to calculate the distributions of the harmonic current and the corresponding ohmic electron power deposition,providing insights into the behavior of nonlinear *** a low driving frequency,i.e.13.56 MHz,no remarkable nonlinear standing waves were identified and the bulk ohmic electron power absorption was observed to be *** harmonic magnetic field/current was found to increase dramatically with the driving frequency,due to decreased sheath reactance and more remarkable nonlinear standing waves at a higher driving frequency,leading to the enhancements of the ohmic heating and the plasma density in the bulk,specifically at the electrode *** a high driving frequency,i.e.60 MHz,the high-order harmonic current density and the corresponding ohmic electron power absorption exhibited a similar node structure,with the main peak on axis,and one or more minor peaks between the electrode center and the edge,contributing to the center-high profile of the plasma density.

关键词： capacitively coupled plasmas magnetic probe nonlinear standing waves ohmic heating