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基于改进Simple Baselines的人体姿态估计算法
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作者 周昆阳 赵梦婷 +1 位作者 张海潮 蒋雯 《电脑与电信》 2021年第3期21-25,共5页
人体姿态估计在很多领域有着十分广泛的应用。为了提高人体姿态估计准确率,提出一种基于Simple Baselines的人体姿态估计算法。首先,将Simple Baselines的特征提取网络ResNet152替换为FastHand算法中的特征提取网络,提高模型检测准确率... 人体姿态估计在很多领域有着十分广泛的应用。为了提高人体姿态估计准确率,提出一种基于Simple Baselines的人体姿态估计算法。首先,将Simple Baselines的特征提取网络ResNet152替换为FastHand算法中的特征提取网络,提高模型检测准确率。其次,引进姿态修正机以提高模型对人体关节点定位准确率。实验结果表明,在COCO test-dev上,模型达到75.8%的AP,相较于Simple Baselines,AP提高2.1%。 展开更多
关键词 人体姿态估计 Simple baselines 姿态修正机 FastHand ResNet152
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基于ESI中全球论文影响力基准值(Baselines)的科研论文奖励政策分析
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作者 于洋 《产业与科技论坛》 2018年第5期123-124,共2页
ESI(Essential Science Indicators,基本科学指标数据库)是现阶段较为认可的评价高等学校、科研机构、国家或地区的科研水平及国际学术影响力的评价分析工具,ESI数据库是基于SCIE/SSCI所收录的10,000多种学术期刊及上千万条文献记录而... ESI(Essential Science Indicators,基本科学指标数据库)是现阶段较为认可的评价高等学校、科研机构、国家或地区的科研水平及国际学术影响力的评价分析工具,ESI数据库是基于SCIE/SSCI所收录的10,000多种学术期刊及上千万条文献记录而建立的计量分析数据库。现阶段,各研究机构针对ESI推出的奖励办法基本只单纯涉及了论文的引用次数奖励,但忽视了ESI中不同学科之间的差异。本文提出的基于ESI中全球论文影响力基准值(Baselines)的科研论文奖励思想,可以有效避免不同ESI学科之间论文引用次数存在较大差异的现象。 展开更多
关键词 ESI baselines 引用奖励
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Subtracting Technique of Baselines for Capillary Electrophoresis Signals
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作者 WANGYing MOJin-yuan +1 位作者 CHENZuan-guang GAOYan 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第2期134-137,共4页
The drifting baselines of capillary electrophoresis affect the veracity of analysis greatly. This paper presents Threshold Fitting Technique(TFT) so as to subtract the baselines from the original signals and emendate ... The drifting baselines of capillary electrophoresis affect the veracity of analysis greatly. This paper presents Threshold Fitting Technique(TFT) so as to subtract the baselines from the original signals and emendate the signals. In TFT, wavelet and curve fitting technique are applied synthetically, thresholds are decided by the computer automatically. Many experiments of signal processing indicate that TFT is simple for being used, there are few man-induced factors, and the results are satisfactory. TFT can be applied for noisy signals without any pre-processing. 展开更多
关键词 BASELINE Capillary electrophoresis(CE) Curve fitting WAVELET THRESHOLD
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Gyrokinetic simulations of the kinetic electron effects on the electrostatic instabilities on the ITER baseline scenario
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作者 Debing ZHANG Pengfei ZHAO +2 位作者 Yingfeng XU Lei YE Xianmei ZHANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第9期109-124,共16页
The linear and nonlinear simulations are carried out using the gyrokinetic code NLT for the electrostatic instabilities in the core region of a deuterium plasma based on the International Thermonuclear Experimental Re... The linear and nonlinear simulations are carried out using the gyrokinetic code NLT for the electrostatic instabilities in the core region of a deuterium plasma based on the International Thermonuclear Experimental Reactor(ITER)baseline scenario.The kinetic electron effects on the linear frequency and nonlinear transport are studied by adopting the adiabatic electron model and the fully drift-kinetic electron model in the NLT code,respectively.The linear simulations focus on the dependence of linear frequency on the plasma parameters,such as the ion and electron temperature gradientsκ_(Ti,e)≡R=L_(Ti,e),the density gradientκ_(n)≡R/L_(n)and the ion-electron temperature ratioτ=T_(e)=T_(i).Here,is the major radius,and T_(e)and T_(i)denote the electron and ion temperatures,respectively.L_(A)=-(δ_(r)lnA)^(-1)is the gradient scale length,with denoting the density,the ion and electron temperatures,respectively.In the kinetic electron model,the ion temperature gradient(ITG)instability and the trapped electron mode(TEM)dominate in the small and large k_(θ)region,respectively,wherek_(θ)is the poloidal wavenumber.The TEMdominant region becomes wider by increasing(decreasing)κ_(T_(e))(κ_(T_(i)))or by decreasingκ_(n).For the nominal parameters of the ITER baseline scenario,the maximum growth rate of dominant ITG instability in the kinetic electron model is about three times larger than that in the adiabatic electron model.The normalized linear frequency depends on the value ofτ,rather than the value of T_(e)or T_(i),in both the adiabatic and kinetic electron models.The nonlinear simulation results show that the ion heat diffusivity in the kinetic electron model is quite a lot larger than that in the adiabatic electron model,the radial structure is finer and the time oscillation is more rapid.In addition,the magnitude of the fluctuated potential at the saturated stage peaks in the ITGdominated region,and contributions from the TEM(dominating in the higher k_(θ)region)to the nonlinear transport can be neglected.In the adiabatic electron model,the zonal radial electric field is found to be mainly driven by the turbulent energy flux,and the contribution of turbulent poloidal Reynolds stress is quite small due to the toroidal shielding effect.However,in the kinetic electron model,the turbulent energy flux is not strong enough to drive the zonal radial electric field in the nonlinear saturated stage.The kinetic electron effects on the mechanism of the turbulence-driven zonal radial electric field should be further investigated. 展开更多
关键词 ITER baseline scenario gyrokinetic simulation kinetic electron effects electrostatic instability
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Estimation of free core nutation parameters and availability of computing options
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作者 Weiwei Yang Xiaoming Cui +2 位作者 Jianqiao Xu Qingchao Liu Ming Qin 《Geodesy and Geodynamics》 EI CSCD 2024年第1期61-74,共14页
The Earth’s Free Core Nutation(FCN) causes Earth tides and forced nutation with frequencies close to the FCN that exhibit resonance effects.High-precision superconducting gravimeter(SG) and very long baseline interfe... The Earth’s Free Core Nutation(FCN) causes Earth tides and forced nutation with frequencies close to the FCN that exhibit resonance effects.High-precision superconducting gravimeter(SG) and very long baseline interferometry(VLBI) provide good observation techniques for detecting the FCN parameters.However,some choices in data processing and solution procedures increase the uncertainty of the FCN parameters.In this study,we analyzed the differences and the effectiveness of weight function and ocean tide corrections in the FCN parameter detection using synthetic data,SG data from thirty-one stations,and the 10 celestial pole offset(CPO) series.The results show that significant discrepancies are caused by different computing options for a single SG station.The stacking method,which results in a variation of0.24-5 sidereal days(SDs) in the FCN period(T) and 10^(3)-10^(4) in the quality factor(Q) due to the selection of the weighting function and the ocean tide model(OTM),can effectively suppress this influence.The statistical analysis results of synthetic data shows that although different weight choices,while adjusting the proportion of diurnal tidal waves involved,do not significantly improve the accuracy of fitted FCN parameters from gravity observations.The study evaluated a series of OTMs using the loading correction efficiency.The fitting of FCN parameters can be improved by selecting the mean of appropriate OTMs based on the evaluation results.Through the estimation of the FCN parameters based on the forced nutation,it was found that the weight function P_(1) is more suitable than others,and different CPO series(after 2009) resulted in a difference of 0.4 SDs in the T and of 103 in the Q.We estimated the FCN parameters for SG(T=430.4±1.5 SDs and Q=1.52×10^(4)±2.5×10^(3)) and for VLBI(T=429.8±0.7 SDs,Q=1.88×10^(4)±2.1×10^(3)). 展开更多
关键词 Free core nutation Superconducting gravimeter Very long baseline interferometry Weight function Ocean tide model
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Mean nocturnal baseline impedance in gastro-esophageal reflux disease diagnosis:Should we strictly follow the Lyon 2 Consensus?
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作者 Theodoros A Voulgaris Georgios P Karamanolis 《World Journal of Gastroenterology》 SCIE CAS 2024年第26期3253-3256,共4页
Clinical practice guidelines drive clinical practice and clinicians rely to them when trying to answer their most common questions.One of the most important position papers in the field of gastro-esophageal reflux dis... Clinical practice guidelines drive clinical practice and clinicians rely to them when trying to answer their most common questions.One of the most important position papers in the field of gastro-esophageal reflux disease(GERD)is the one produced by the Lyon Consensus.Recently an updated second version has been released.Mean nocturnal baseline impedance(MNBI)was proposed by the first Consensus to act as supportive evidence for GERD diagnosis.Originally a cut-off of 2292 Ohms was proposed,a value revised in the second edition.The updated Consensus recommended that an MNBI<1500 Ohms strongly suggests GERD while a value>2500 Ohms can be used to refute GERD.The proposed cut-offs move in the correct direction by diminishing the original cut-off,nevertheless they arise from a study of normal subjects where cut-offs were provided by measuring the mean value±2SD and not in symptomatic patients.However,data exist that even symptomatic patients with inconclusive disease or reflux hypersensitivity(RH)show lower MNBI values in comparison to normal subjects or patients with functional heartburn(FH).Moreover,according to the data,MNBI,even among symptomatic patients,is affected by age and body mass index.Also,various studies have proposed different cut-offs by using receiver operating characteristic curve analysis even lower than the one proposed.Finally,no information is given for patients submitted to on-proton pump inhibitors pH-impedance studies even if new and extremely important data now exist.Therefore,even if MNBI is an extremely important tool when trying to approach patients with reflux symptoms and could distinguish conclusive GERD from RH or FH,its values should be interpreted with caution. 展开更多
关键词 Mean nocturnal baseline impedance Gastro-esophageal reflux disease Lyon 2 Consensus pH-impedance DIAGNOSIS
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A New Result on Regular Designs under Baseline Parameterization
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作者 Mengru Qin Yuna Zhao 《Open Journal of Applied Sciences》 2024年第2期441-449,共9页
The study on designs for the baseline parameterization has aroused attention in recent years. This paper focuses on two-level regular designs for the baseline parameterization. A general result on the relationship bet... The study on designs for the baseline parameterization has aroused attention in recent years. This paper focuses on two-level regular designs for the baseline parameterization. A general result on the relationship between K-aberration and word length pattern is developed. 展开更多
关键词 Baseline Parameterization K-Aberration Regular Design Word Length Pattern
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Application of ACP Nonlinear Math in Analyzing Arithmetic and Radiation Transmission Data (Application 1 & 2) [4-21-2024, 820P] (V)
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作者 Ralph W. Lai Melisa W. Lai-Becker Grace Cheng-Dodge 《Journal of Applied Mathematics and Physics》 2024年第6期2302-2319,共18页
In this study, we explore the application of ACP (asymptotic curve based and proportionality oriented) Alpha Beta (αβ) Nonlinear Math to analyze arithmetic and radiation transmission data. Specifically, we investiga... In this study, we explore the application of ACP (asymptotic curve based and proportionality oriented) Alpha Beta (αβ) Nonlinear Math to analyze arithmetic and radiation transmission data. Specifically, we investigate the relationship between two variables. The novel approach involves collecting elementary “y” data and subsequently analyzing the asymptotic cumulative or demulative (opposite of cumulative) Y data. In part I, we examine the connection between the common linear numbers and ideal nonlinear numbers. In part II, we delve into the relationship between X-ray energy and the radiation transmission for various thin film materials. The fundamental physical law asserts that the nonlinear change in continuous variable Y is negatively proportional to the nonlinear change in continuous variable X, expressed mathematically as dα = −Kdβ. Here: dα {Y, Yu, Yb} represents the change in Y, with Yu and Yb denoting the upper and baseline asymptote of Y. dβ {X, Xu, Xb} represents the change in X, with Xu and Xb denoting the upper and baseline asymptote of X. K represents the proportionality constant or rate constant, which varies based on equation arrangement. K is the key inferential factor for describing physical phenomena. 展开更多
关键词 Asymptotic Concave and Convex Curve Upper and Baseline Asymptote Demulative vs. Cumulative Coefficient of Determination Proportionalityand Position Constant Skewed Bell and Sigmoid Curve
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Emission Baselines for Clean Development Mechanism Projects: Residential Heating Case in Beijing
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作者 郭京菲 马玉清 《Tsinghua Science and Technology》 EI CAS 2000年第3期328-332,共5页
To explore emission baseline, technically the most difficult issue for Clean Development Mechanism (CDM) project development, as well as to examine whether CDM is a possible way to help Beijing restructure its heating... To explore emission baseline, technically the most difficult issue for Clean Development Mechanism (CDM) project development, as well as to examine whether CDM is a possible way to help Beijing restructure its heating energy consumption, this paper conducts a CDM baseline case study on residential heating in Beijing. Based on investigation, energy consumption forecast and economic analysis of future technology options, the technology benchmark and site specific baselines for both retrofit projects and new heating projects have been discussed. The results indicate that fuel switching from coal to natural gas can meet the additionality criteria in many cases and will be the main type of CDM project. In addition, it also proves that the technology benchmark and the case by case baseline setting approach are applicable for future CDM cooperation projects on heating in Beijing. 展开更多
关键词 clean development mechanism district heating baseline determination
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Carbon emission reduction accounting method for a CCUS-EOR project 被引量:4
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作者 WANG Fang LIAO Guangzhi +3 位作者 SU Chunmei WANG Feng MA Jianguo YANG Yongzhi 《Petroleum Exploration and Development》 SCIE 2023年第4期989-1000,共12页
It is difficult to quantify and certify the greenhouse gas(GHG)emission reduction in the entire process of a project of carbon capture,utilization and storage(CCUS)-enhanced oil recovery(EOR).Under the methodological ... It is difficult to quantify and certify the greenhouse gas(GHG)emission reduction in the entire process of a project of carbon capture,utilization and storage(CCUS)-enhanced oil recovery(EOR).Under the methodological framework for GHG voluntary emission reduction project,the carbon emission reduction accounting method for CCUS-EOR project was established after examining the accounting boundaries in process links,the baseline emission and project emission accounting methods,and the emission and leakage quantification and prediction models,in order to provide a certification basis for the quantification of GHG emission reduction in the CCUS-EOR project.Based on the data of energy consumption,emission and leakage monitoring of the CCUS-EOR industrial demonstration project in Jilin Oilfield,the net emission reduction efficiency is determined to be about 91.1%at the current storage efficiency of 80%.The accounting and prediction of carbon emission reduction for CCUS-EOR projects with different concentrations and scales indicate that within the project accounting boundary,the certified net emission reduction efficiency of the low-concentration gas source CCUS-EOR projects represented by coal-fired power plants is about 37.1%,and the certified net emission reduction efficiency of the high-concentration gas source CCUS-EOR projects represented by natural gas hydrogen production is about 88.9%.The proposed method is applicable to the carbon emission reduction accounting for CCUS-EOR projects under multiple baseline scenarios during the certification period,which can provide decision-making basis for the planning and deployment of CCUS-EOR projects. 展开更多
关键词 CCUS-EOR carbon emission accounting accounting boundary baseline emission
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TOA positioning algorithm of LBL system for underwater target based on PSO 被引量:2
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作者 XING Yao WANG Jiongqi +3 位作者 HE Zhangming ZHOU Xuanying CHEN Yuyun PAN Xiaogang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第5期1319-1332,共14页
For the underwater long baseline(LBL)positioning systems,the traditional distance intersection algorithm simplifies the sound speed to a constant,and calculates the underwa-ter target position parameters with a nonlin... For the underwater long baseline(LBL)positioning systems,the traditional distance intersection algorithm simplifies the sound speed to a constant,and calculates the underwa-ter target position parameters with a nonlinear iteration.However,due to the complex underwater environment,the sound speed changes with time and space,and then the acoustic propagation path is actually a curve,which inevitably causes some errors to the traditional distance intersection positioning algorithm.To reduce the position error caused by the uncertain underwater sound speed,a new time of arrival(TOA)intersection underwater positioning algorithm of LBL system is proposed.Firstly,combined with the vertical layered model of the underwater sound speed,an implicit positioning model of TOA intersection is constructed through the constant gradient acoustic ray tracing.And then an optimization function based on the overall TOA residual square sum is advanced to solve the position parameters for the underwater target.Moreover,the particle swarm optimization(PSO)algorithm is replaced with the tra-ditional nonlinear least square method to optimize the implicit positioning model of TOA intersection.Compared with the traditional distance intersection positioning model,the TOA intersec-tion positioning model is more suitable for the engineering practice and the optimization algorithm is more effective.Simulation results show that the proposed methods in this paper can effectively improve the positioning accuracy for the underwater target. 展开更多
关键词 long baseline(LBL)positioning system sound speed profile constant gradient acoustic ray tracing time of arrival(TOA)intersection model particle swarm optimization(PSO)
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Obtaining accurate measurements of the sea surface height from a GPS buoy 被引量:1
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作者 Wanlin Zhai Jianhua Zhu +5 位作者 Chuntao Chen Wu Zhou Longhao Yan Yufei Zhang Xiaoqi Huang Kai Guo 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第6期78-88,共11页
A dedicated GPS buoy is designed for calibration and validation(Cal/Val)of satellite altimeters since 2014.In order to evaluate the accuracy of the sea surface height(SSH)measured by the GPS buoy,twelve campaigns have... A dedicated GPS buoy is designed for calibration and validation(Cal/Val)of satellite altimeters since 2014.In order to evaluate the accuracy of the sea surface height(SSH)measured by the GPS buoy,twelve campaigns have been done within China sea area between 2014 and 2021.In six of these campaigns,two static Global Navigation Satellite System stations were installed at distances of<1 km and 19 km from the buoy to assess how the baseline length influenced the derived SSH from the buoy solutions.The GPS buoy data was processed using the GAMIT/GLOBK software+TRACK module and CSRS-PPP tool to achieve the SSH.The SSH was compared with conventionally tide gauge(TG)data to evaluate the accuracy of the buoy with the standard deviation of the height element.The results showed that the difference in the standard deviation of the SSH from the buoy and the TG was less than 16 mm.The SSHs processed with different ephemeris(Ultra-Rapid,Rapid,Final)were not significantly different.When the baseline length was 19 km,the SSH solution of the GPS buoy performed well,with standard bias of less than 26 mm between the heights measured by the buoy and TG,meaning that the buoy could be used for Cal/Val of altimeters.The bias between the Canadian Spatial Reference System-precise point positioning tool and the TRACK varied a lot,and some of them were over 130 mm.This deemed too high to be useful for Cal/Val of satellite altimeters.Moreover,the GPS buoy solutions processed by GAMIT/GLOBK software+TRACK module were used for in-orbit Cal/Val of HY-2B/C satellites in ten campaigns.The SSH and significant wave height of the altimeters showed good agreements with the GPS buoy solutions. 展开更多
关键词 GPS buoy sea surface height baseline length precise point positioning satellite altimeter HY-2
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Influence of water conservancy project on runoff in the source region of the Yellow River and wetland changes in the Lakeside Zone,China
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作者 Ming-nan Yang Liang Zhu +2 位作者 Jing-tao Liu Yu-xi Zhang Bing Zhou 《Journal of Groundwater Science and Engineering》 2023年第4期333-346,共14页
The source area of the Yellow River(SAYR),located above the Huangheyan hydrological station,is important for ecological preservation and water source conservation in the Yellow River Basin.In this area,the impact of w... The source area of the Yellow River(SAYR),located above the Huangheyan hydrological station,is important for ecological preservation and water source conservation in the Yellow River Basin.In this area,the impact of water conservation projects on the hydrology and the ecological environment is pivotal in protecting water resources and alpine vegetation ecosystems.This study investigates the impact of the Yellow River Source Hydropower Station on the runoff and ecological evolution of the SAYR,along with the underlying mechanism,using extensive datasets encompassing long-term meteorological,hydrological and remote sensing data from various time periods.Results show that,over the long term,precipitation is the primary factor driving runoff variations in the SAYR.Nevertheless,from 1990 to 2020,there is a notably inconsistent relationship between precipitation and runoff.After the completion of the Yellow River Source Hydropower Station in 2001,the water level of Eling Lake experienced and elevation of 2–3 m,leading to a gradual recovery of runoff.In addition,the basin's water balance shifted from a negative to a positive equilibrium,oscillating with changes in lake water levels.Consequently,the overflow zone of the Tangchama alluvial–proluvial fan in the upper reaches of the lakeshore shifted by 500 m,and marsh wetlands expanded by 20.78 km^(2).The increased storage of lakes and groundwater in the SAYR is the key controlling factor for the runoff recovery,changes in the basin's water balance,and enhancements in lakeshore vegetation ecology.Under the geological background of the Qinghai–Tibet Plateau's upliftment and intensified upstream river erosion,the basin experienced a substantial water imbalance due to declining discharge base levels,which is the most critical factor behind runoff attenuation in the SAYR towards the end of the 20th century.The construction of the hydropower station objectively raised the drainage base level of the basin,thereby positively contributing to the preservation of water balance,runoff stability,and the enhancement of swamps and wetlands along the lakeshore. 展开更多
关键词 GROUNDWATER Discharge baseline Wetland ecology RUNOFF Climate change
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Prevalence of gastroesophageal reflux disease in children with extraesophageal manifestations using combined-video,multichannel intraluminal impedance-pH study
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作者 Sutha Eiamkulbutr Termpong Dumrisilp +1 位作者 Anapat Sanpavat Palittiya Sintusek 《World Journal of Clinical Pediatrics》 2023年第3期151-161,共11页
BACKGROUND Gastroesophageal reflux disease(GERD)might be either a cause or comorbidity in children with extraesophageal problems especially as refractory respiratory symptoms,without any best methods or criterion for ... BACKGROUND Gastroesophageal reflux disease(GERD)might be either a cause or comorbidity in children with extraesophageal problems especially as refractory respiratory symptoms,without any best methods or criterion for diagnosing it in children.AIM To evaluate the prevalence of extraesophageal GERD using conventional and combined-video,multichannel intraluminal impedance-pH(MII-pH),and to propose novel diagnostic parameters.METHODS The study was conducted among children suspected of extraesophageal GERD at King Chulalongkorn Memorial Hospital between 2019 and 2022.The children underwent conventional and/or combined-video MII-pH.The potential parameters were assessed and receiver operating characteristic was used for the significant parameters.RESULTS Of 51 patients(52.9%males),aged 2.24 years were recruited.The common problems were cough,recurrent pneumonia,and hypersecretion.Using MII-pH,35.3%of the children were diagnosed with GERD by reflux index(31.4%),total reflux events(3.9%),and symptom indices(9.8%)with higher symptom recorded in the GERD group(94 vs 171,P=0.033).In the video monitoring group(n=17),there were more symptoms recorded(120 vs 220,P=0.062)and more GERD(11.8%vs 29.4%,P=0.398)by symptom indices.Longest reflux time and mean nocturnal baseline impedance were significant parameters for diagnosis with receiver operating characteristic areas of 0.907(P=0.001)and 0.726(P=0.014).CONCLUSION The prevalence of extraesophageal GERD in children was not high as expected.The diagnostic yield of symptom indices increased using video monitoring.Long reflux time and mean nocturnal baseline impedance are novel parameters that should be integrated into the GERD diagnostic criteria in children. 展开更多
关键词 Extraesophageal reflux pH-impedance CHILDREN Gastroesophageal reflux Mean nocturnal baseline impedance
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基于Baseline模型的刮板输送机健康评估
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作者 鲍新平 何勇 +2 位作者 马正武 黄家林 冯敬培 《煤矿机械》 2023年第11期204-206,共3页
对刮板输送机进行可靠健康评估是保证工作面高效开采的关键。针对某煤矿综采工作面刮板输送机提出一种基于Baseline模型的健康评估方法。该方法采用长短时记忆(LSTM)深度神经网络建立运行参数的Baseline模型,预测正常的数值和故障发生... 对刮板输送机进行可靠健康评估是保证工作面高效开采的关键。针对某煤矿综采工作面刮板输送机提出一种基于Baseline模型的健康评估方法。该方法采用长短时记忆(LSTM)深度神经网络建立运行参数的Baseline模型,预测正常的数值和故障发生上、下限阈值。在此基础上建立了真实值与预测值的6种偏差计算方法和设备健康评估机制。最后融合机头电机、机尾电机、机头减速器和机尾减速器的评估结果,完成刮板输送机运行健康综合评估。 展开更多
关键词 刮板输送机 健康评估 Baseline模型 深度神经网络
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SBAS-InSAR技术监测青藏高原季节性冻土形变 被引量:111
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作者 李珊珊 李志伟 +2 位作者 胡俊 孙倩 俞晓莹 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2013年第5期1476-1486,共11页
冻土的冻结和融化的反复交替会造成地质环境与结构的破坏,从而导致房屋和道路等地面工程建筑物的地基破裂或者塌陷,还会引起山体滑坡、洪水暴发以及冰川移动等.因此,监测冻土形变对确保冻土区工程建筑的稳定性和安全性,同时保证冻土区... 冻土的冻结和融化的反复交替会造成地质环境与结构的破坏,从而导致房屋和道路等地面工程建筑物的地基破裂或者塌陷,还会引起山体滑坡、洪水暴发以及冰川移动等.因此,监测冻土形变对确保冻土区工程建筑的稳定性和安全性,同时保证冻土区社会经济可持续发展具有重要的意义.目前,在冻土监测方面并没有能大面积监测冻土形变时间演化情况的有效方法,本文提出将InSAR技术中的小基线集方法(SBAS-InSAR)应用于监测冻土来获取其形变时间序列中.考虑到冻土形变呈现明显的季节性特征,本文提出利用周期形变模型来代替传统SBAS方法中的线性形变模型,从而更好地分离出高程残差和大气误差.利用ENVISAT卫星获取的21景ASAR影像图作为实验数据,采用改进的SBAS技术成功获取了青藏高原从羊八井站至当雄站铁路段冻土区的地表形变时间序列图,揭示了该冻土区从2007年到2010年的季节性形变演化情况.通过与研究地区温度变化的联合分析,发现所得到的地表形变结果与冻土的物理变化规律非常吻合,证明了SBAS-InSAR技术在冻土形变监测中具有良好的发展应用前景. 展开更多
关键词 冻土 INSAR SBAS (Small BASELINE subset) 青藏高原 形变监测
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基于短基线集方法(SBAS-INSAR)技术的山区城市地面沉降监测研究——以攀枝花为例 被引量:18
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作者 孟庆凯 汪宝存 苗放 《科学技术与工程》 北大核心 2016年第13期12-17,共6页
基于合成孔径雷达干涉(interferometric synthetic aperture radar,INSAR)技术的山区城市地面沉降研究,因地形复杂、植被覆盖等因素开展较少。首次在攀枝花市,利用12景2009-2010ENVISAT ASAR数据,采用短基线集方法开展大范围、长时间监... 基于合成孔径雷达干涉(interferometric synthetic aperture radar,INSAR)技术的山区城市地面沉降研究,因地形复杂、植被覆盖等因素开展较少。首次在攀枝花市,利用12景2009-2010ENVISAT ASAR数据,采用短基线集方法开展大范围、长时间监测。结果表明,攀枝花市东区地面沉降较大,沉降的平均速率高达48 mm/年;西区沉降较小,沉降平均速率10 mm/年。推测原因多为城市化建设所致地面荷载;而市东北方向的露天矿区,因连续开采所致,不同时期同一地点的地表变化,导致高相干点在此区域分散稀疏,不能表明是否有沉降现象。 展开更多
关键词 地面沉降 短基线集(sinall BASELINE subset SBAS) 时序分析 攀枝花
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Finite element model updating and validating of Runyang Suspension Bridge based on SHMS 被引量:7
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作者 王浩 李爱群 缪长青 《Journal of Southeast University(English Edition)》 EI CAS 2005年第4期474-479,共6页
Based on the finite element (FE) program ANSYS, a three-dimensional model for the Runyang Suspension Bridge (RSB) is established. The structural natural frequency, vibration mode, stress and displacement response ... Based on the finite element (FE) program ANSYS, a three-dimensional model for the Runyang Suspension Bridge (RSB) is established. The structural natural frequency, vibration mode, stress and displacement response under various load cases are given. A new method of FE model updating is presented based on the physical meaning of sensitivity and the penalty function concept. In this method, the structural model is updated by modifying the parameters of design, and validated by structural natural vibration characteristics, stress response as well as displacement response. The design parameters used for updating are bounded according to measured static response and engineering judgment. The FE model of RSB is updated and validated by the measurements coming from the structural health monitoring system (SHMS), and the FE baseline model reflecting the current state of RSB is achieved. Both the dynamic and static results show that the method is effective in updating the FE model of long span suspension bridges. The results obtained provide an important research basis for damage alarming and health monitoring of the RSB. 展开更多
关键词 suspension bridge finite element model updating model validating baseline model structural health monitoring system (SHMS)
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Cooperative navigation and localization for multiple UUVs 被引量:3
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作者 张立川 徐德民 +1 位作者 刘明雍 严卫生 《Journal of Marine Science and Application》 2009年第3期216-221,共6页
The authors proposed a moving long baseline algorithm based on the extended Kalman filter (EKF) for cooperative navigation and localization of multi-unmanned underwater vehicles (UUVs). Research on cooperative nav... The authors proposed a moving long baseline algorithm based on the extended Kalman filter (EKF) for cooperative navigation and localization of multi-unmanned underwater vehicles (UUVs). Research on cooperative navigation and localization for multi-UUVs is important to solve navigation problems that restrict long and deep excursions. The authors investigated improvements in navigation accuracy. In the moving long base line (MLBL) structure, the master UUV is equipped with a high precision navigation system as a node of the moving long baseline, and the slave UUV is equipped with a low precision navigation system. They are both equipped with acoustic devices to measure relative location. Using traditional triangulation methods to calculate the position of the slave UUV may cause a faulty solution. An EKF was designed to solve this, combining the proprioceptive and exteroceptive sensors. Research results proved that the navigational accuracy is improved significantly with the MLBL method based on EKF. 展开更多
关键词 navigation system moving long baseline multi-UUVs cooperative navigation and localization extended Kalman filter (EKF)
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Baseline Sensitivity of Botrytis cinerea from Liaoning Province to Boscalid 被引量:3
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作者 刘妍 祁之秋 +2 位作者 韩宝艳 赵铂锤 纪明山 《Agricultural Science & Technology》 CAS 2015年第11期2531-2534,共4页
[Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. T... [Objective] This study aimed to avoid and delay the generation of resis- tance in Botrytis cinerea to boscalid. [Method] The sensitivity of Botrytis cinerea to boscalid was tested by the mycelial growth rate method. The distribution of sensitivity variation of B. cinerea to boscalid in different regions was cleared, and the sen- sitivity baseline of B. cinerea from Liaoning Province to boscalid was established. [Result] The ECso values of B. cinerea strains from Liaoning Province ranged from 0.080 0 to 7.787 2μg/ml, and the highest ECho value was 97.34 times higher than the minimum. The average EC50 value (1.973μg/ml) of the 158 strains was treated as the baseline sensitivity of B. cinerea from Liaoning Province to boscalid. [Conclu- sion] It is essential to conduct a risk assessment of drug resistance in B. cinerea to boscalid. 展开更多
关键词 TOMATO Botrytis cinerea BOSCALID Sensitivity Baseline sensitivity
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