期刊文献+
共找到2,708篇文章
< 1 2 136 >
每页显示 20 50 100
Curative effect observation on deformed auricle treated with EarWell Infant Ear Correction System with modular parents'nursing education 被引量:2
1
作者 Wei Wei Ren-Zhong Luo +1 位作者 Zhen-Yun Huang Rui Mi 《Frontiers of Nursing》 CAS 2020年第2期153-159,共7页
Objective:To investigate the efficacy and patient satisfaction of the EarWell Infant Ear Correction System combined with modular parents'nursing education's curative effect on deformed auricle.Methods:A total ... Objective:To investigate the efficacy and patient satisfaction of the EarWell Infant Ear Correction System combined with modular parents'nursing education's curative effect on deformed auricle.Methods:A total of 42 patients(29 boys and 13 girls;73 ears;age≤3 months)with auricle deformities who had received EarWell Infant Ear Correction System's treatment and modular parents'nursing education in Guangzhou Children and Women's Medical Center between April and October 2018.The modular parents'education program is standardized by EarWell system.Physician and patients'parents compared the severity of auricle deformity separately before and after the treatment by using the auricle deformities visual analogue scales(VAS)rating system.Patient satisfaction was evaluated by using global aesthetic improvement scale(GAIS).The data collected of auricle deformities VAS and GAIS satisfaction score were applied to measure the treatment's effectiveness.Results:All the 42 patients(73 external ears)completed the treatment with EarWell Infant Ear Correction System and modular parents'nursing education.The mean age at initiation of treatment was 37.87±19.44 days and the therapeutic time span was 47.21±17.36 days.At the end of treatment,the physician's and patients'guardians rating of the severity of auricle deformity were significantly improved separately compared to the initial rating(8.33±1.27 vs.6.51±0.84;P<0.005)(5.77±1.59 vs.8.19±2.38 P<0.05).During the treatment and parents'home nursing care period,the side effect and complications were minor like skin eczema and irrigation;there were no severe complications such as necrosis of the skin and cartilage.The patient tolerance for the treatment was acceptable with the adequate parents'nursing care.Most patients'guardians were satisfied with the treatment outcomes of EarWell Infant Ear Correction System with more engagement of nursing care,the GAIS's rating were increased from pretreatment stage's 26.19%to treatment completed stage's 90.48%,and the difference was statistically significant(P<0.05).Conclusions:In this study,we proved that EarWell Infant Ear Correction System with its unique parents'modular nursing care education,as a noninvasive treatment,reasonably improved auricle morphological malformation,and patients'guardians satisfaction with few complications,which is worthy of a wildly clinical promotion. 展开更多
关键词 EarWell Infant Ear correction system modular parents'nursing care education auricle deformities VAS rating system GAIS rating system
暂未订购
Vision Sensing-Based Online Correction System for Robotic Weld Grinding 被引量:1
2
作者 Jimin Ge Zhaohui Deng +3 位作者 Shuixian Wang Zhongyang Li Wei Liu Jiaxu Nie 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第5期97-108,共12页
The service cycle and dynamic performance of structural parts are afected by the weld grinding accuracy and surface consistency. Because of reasons such as assembly errors and thermal deformation, the actual track of ... The service cycle and dynamic performance of structural parts are afected by the weld grinding accuracy and surface consistency. Because of reasons such as assembly errors and thermal deformation, the actual track of the robot does not coincide with the theoretical track when the weld is ground ofine, resulting in poor workpiece surface quality. Considering these problems, in this study, a vision sensing-based online correction system for robotic weld grinding was developed. The system mainly included three subsystems: weld feature extraction, grinding, and robot real-time control. The grinding equipment was frst set as a substation for the robot using the WorkVisual software. The input/output (I/O) ports for communication between the robot and the grinding equipment were confgured via the I/O mapping function to enable the robot to control the grinding equipment (start, stop, and speed control). Subsequently, the Ethernet KRL software package was used to write the data interaction structure to realize realtime communication between the robot and the laser vision system. To correct the measurement error caused by the bending deformation of the workpiece, we established a surface profle model of the base material in the weld area using a polynomial ftting algorithm to compensate for the measurement data. The corrected extracted weld width and height errors were reduced by 2.01% and 9.3%, respectively. Online weld seam extraction and correction experiments verifed the efectiveness of the system’s correction function, and the system could control the grinding trajectory error within 0.2 mm. The reliability of the system was verifed through actual weld grinding experiments. The roughness, Ra, could reach 0.504 µm and the average residual height was within 0.21 mm. In this study, we developed a vision sensing-based online correction system for robotic weld grinding with a good correction efect and high robustness. 展开更多
关键词 Online correction system ROBOT GRINDING Weld seam Laser vision sensor
在线阅读 下载PDF
Comparison of the treatment duration and nursing requirements of the EarWell infant ear correction system for different types of auricle deformities
3
作者 Wei Wei Chang-Zhi Sun +4 位作者 Xiao-Ya Wang Jie Zhong Qian-Jun Liao Yan-Ying Cai Rui Mi 《Frontiers of Nursing》 2023年第3期357-362,共6页
Objective:To observe whether the Ear Well infant ear correction system makes any difference in terms of the treatment effect,duration,complication rate,and nursing care requirements in different types of infant auricl... Objective:To observe whether the Ear Well infant ear correction system makes any difference in terms of the treatment effect,duration,complication rate,and nursing care requirements in different types of infant auricle deformities.Methods:A total of 93 infant patients with auricular deformity(age:<3 months of age)who were diagnosed and treated in Guangzhou Children and Women’s Medical Center from April 2018 to September 2020 were selected and treated with the Ear Well infant ear correction system.We observed and recorded the effects of the Ear Well infant ear correction system,the treatment duration,the number of rebound cases,and complications that are likely to occur during treatment,and noted the related factors causing complications and the relative requirements for nursing care.Results:The Earwell infant ear correction system could effectively correct infant auricle deformities.Among the 93 cases,90 cases had positive therapeutical outcome and the effective rate was 96.77%.The treatment duration for lop ear and protruding ear was longer than for other auricle deformities;the deformity recoil and the treatment compilation rates were much higher for these 2 deformity types,and the difference was statistically significant(P<0.05).Conclusions:The treatment suggestion for the wearing duration of the Ear Well infant ear correction system for lop ear and protruding ear is a prolonged duration compared with that for other infant auricle deformities.Fur ther,the requirements for nursing care intensity and infant patient’s guardian’s nursing knowledge and skill are obviously increased for these 2 types of auricle deformities. 展开更多
关键词 complication rate correction effect EarWell infant ear correction system infant auricle deformities nursing care and patient guardian education treatment duration
暂未订购
Research on variable-speed scanning method for airborne area-array whiskbroom imaging system based on vertical flight path correction
4
作者 JIN Jia-Rong HAN Gui-Cheng +2 位作者 ANG Chong-Ru WU Ren-Fei WANG Yue-Ming 《红外与毫米波学报》 北大核心 2025年第4期511-519,共9页
Airborne area-array whisk-broom imaging systems typically adopt constant-speed scanning schemes.For large-inertia scanning systems,constant-speed scanning requires substantial time to complete the reversal motion,redu... Airborne area-array whisk-broom imaging systems typically adopt constant-speed scanning schemes.For large-inertia scanning systems,constant-speed scanning requires substantial time to complete the reversal motion,reducing the system's adaptability to high-speed reversal scanning and decreasing scanning efficiency.This study proposes a novel sinusoidal variable-speed roll scanning strategy,which reduces abrupt changes in speed and acceleration,minimizing time loss during reversals.Based on the forward image motion compensation strategy in the pitch direction,we establish a line-of-sight(LOS)position calculation model with vertical flight path correction(VFPC),ensuring that the central LOS of the scanned image remains stable on the same horizontal line,facilitating accurate image stitching in whisk-broom imaging.Through theoretical analysis and simulation experiments,the proposed method improves the scanning efficiency by approximately 18.6%at a 90o whiskbroom imaging angle under the same speed height ratio conditions.The new VFPC method enables wide-field,high-resolution imaging,achieving single-line LOS horizontal stability with an accuracy of better than O.4 mrad.The research is of great significance to promote the further development of airborne area-array whisk-broom imaging technology toward wider fields of view,higher speed height ratios,and greater scanning efficiency. 展开更多
关键词 airborne remote sensing whisk-broom imaging image motion vertical flight path correction(VFPC) line-of-sight(LOS)stabilization
在线阅读 下载PDF
Systematic Review of Phase Aberration Correction Algorithms for Transcranial Focused Ultrasound
5
作者 Mingyu Wang Zhouyang Xu Bingbing Cheng 《iRADIOLOGY》 2025年第1期26-46,共21页
Transcranial focused ultrasound(tFUS)is an emerging modality with strong potential for non-invasively treating brain disorders.However,the inhomogeneity and complex structure of the skull induce substantial phase aber... Transcranial focused ultrasound(tFUS)is an emerging modality with strong potential for non-invasively treating brain disorders.However,the inhomogeneity and complex structure of the skull induce substantial phase aberrations and pressure attenuation;these can distort and shift the acoustic focus,thus hindering the efficiency of tFUS therapy.To achieve effective treatments,phased array transducers combined with aberration correction algorithms are commonly implemented.The present report aims to provide a comprehensive review of the current methods used for tFUS phase aberration correction.We first searched the PubMed and Web of Science databases for studies on phase aberration correction algorithms,identifying 54 articles for review.Relevant information,including the principles of algorithms and refocusing performances,were then extracted from the selected articles.The phase correction algorithms involved two main steps:acoustic field estimation and transmitted pulse adjustment.Our review identified key benchmarks for evaluating the effectiveness of these algorithms,each of which was used in at least three studies.These benchmarks included pressure and intensity,positioning error,focal region size,peak sidelobe ratio,and computational efficiency.Algorithm performances varied under different benchmarks,thus highlighting the importance of application-specific algorithm selection for achieving optimal tFUS therapy outcomes.The present review provides a thorough overview and comparison of various phase correction algorithms,and may offer valuable guidance to tFUS researchers when selecting appropriate phase correction algorithms for specific applications. 展开更多
关键词 brain disorders phase correction skull aberration transcranial focused ultrasound
暂未订购
Correction models of Reynolds number effects for through-flow method in axial compressors
6
作者 Xiaochen WANG Chunwei GU 《Chinese Journal of Aeronautics》 2026年第1期78-94,共17页
Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages ha... Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages have difficulties in predicting comprehensively Reynolds number effects on airfoils,matching and characteristics curves.This study proposes Re-correction models for loss,deviation angle and endwall blockage based on classical theories and cascade tests,and loss and deviation models show good agreement in test data of NACA65 and C4 cascades.Throughflow method considering Reynolds number effects is developed by integrating the correction models into a verified Streamline Curvature(SLC)tool.A three-stage axial compressor is investigated through SLC and CFD methods from design Reynolds number(Red=2106)to low Re=4104,and the numerical methods are validated with test data of characteristic curves and spanwise distributions at Red.With Re reduction,SLC method with correction models well predicts variation in overall performances compared with CFD calculations and Wassell's model.Streamwise and spanwise matching such as total pressure and loss distributions in SLC predictions are basically consistent with those in CFD results at near-stall points under design and low Reynolds numbers.SLC and CFD methods share similar detections of stall risks in the third stage(Stg3),and their analyses of diffusion processes deviate to some extent due to different predictions in separated endwall flow.The correction models can be adopted to consider Reynolds number effects in through-flow design and analysis of axial compressors. 展开更多
关键词 Axial compressor Reynolds number effects correction model Through-flow method Aerodynamic performance
原文传递
Ultrasonic Defect Localization Correction Method under the Influence of Non-Uniform Temperature Field
7
作者 Jianhua Du Shaofeng Wang +2 位作者 Ting Gao Huiwen Sun Wenjing Liu 《Structural Durability & Health Monitoring》 2026年第1期235-250,共16页
In ultrasonic non-destructive testing of high-temperature industrial equipment,sound velocity drift induced by non-uniform temperature fields can severely compromise defect localization accuracy.Conventional approache... In ultrasonic non-destructive testing of high-temperature industrial equipment,sound velocity drift induced by non-uniform temperature fields can severely compromise defect localization accuracy.Conventional approaches that rely on room-temperature sound velocities introduce systematic errors,potentially leading to misjudgment of safety-critical components.Two primary challenges hinder current methods:first,it is difficult to monitor real-time changes in sound velocity distribution within a thermal gradient;second,traditional uniform-temperature correction models fail to capture the nonlinear dependence of material properties on temperature and their effect on ultrasonic velocity fields.Here,we propose a defect localization correction method based on multiphysics coupling.A two-dimensional coupled heat transfer–wave propagation model is established in COMSOL,and a one-dimensional steady-state heat transfer condition is used to design a numerical pulse–echo experiment in 1020 steel.Temperature-dependent material properties are incorporated,and the intrinsic relationship between sound velocity and temperature is derived,confirming consistency with classical theories.To account for gradient temperature fields,a micro-element integration algorithm discretizes the propagation path into segments,each associated with a locally computed temperature from the steady-state heat conduction solution.Defect positions are dynamically corrected through cumulative displacement along the propagation path.By integrating heat conduction and elastic wave propagation in a multiphysics framework,this method overcomes the limitations of uniform-temperature assumptions.The micro-element integration approach enables dynamic tracking of spatially varying sound velocities,offering a robust strategy to enhance ultrasonic testing accuracy in high-temperature industrial environments. 展开更多
关键词 Ultrasonic testing nonuniform temperature field sound velocity correction defect localization multiple physical field coupling
在线阅读 下载PDF
A TimeXer-Based Numerical Forecast Correction Model Optimized by an Exogenous-Variable Attention Mechanism
8
作者 Yongmei Zhang Tianxin Zhang Linghua Tian 《Computers, Materials & Continua》 2026年第3期1770-1785,共16页
Marine forecasting is critical for navigation safety and disaster prevention.However,traditional ocean numerical forecasting models are often limited by substantial errors and inadequate capture of temporal-spatial fe... Marine forecasting is critical for navigation safety and disaster prevention.However,traditional ocean numerical forecasting models are often limited by substantial errors and inadequate capture of temporal-spatial features.To address the limitations,the paper proposes a TimeXer-based numerical forecast correction model optimized by an exogenous-variable attention mechanism.The model treats target forecast values as internal variables,and incorporates historical temporal-spatial data and seven-day numerical forecast results from traditional models as external variables based on the embedding strategy of TimeXer.Using a self-attention structure,the model captures correlations between exogenous variables and target sequences,explores intrinsic multi-dimensional relationships,and subsequently corrects endogenous variables with the mined exogenous features.The model’s performance is evaluated using metrics including MSE(Mean Squared Error),MAE(Mean Absolute Error),RMSE(Root Mean Square Error),MAPE(Mean Absolute Percentage Error),MSPE(Mean Square Percentage Error),and computational time,with TimeXer and PatchTST models serving as benchmarks.Experiment results show that the proposed model achieves lower errors and higher correction accuracy for both one-day and seven-day forecasts. 展开更多
关键词 TimeXer model exogenous variable attention mechanism sea surface temperature temporal-spatial features forecast correction
在线阅读 下载PDF
Analysis of In-Station Pressure Drops in Shale Gas Gathering Systems Using CFD and Network Modeling
9
作者 Kunyi Wu Bo Lei +5 位作者 Yanhua Qiu Hui Li Shize Wei Feng Wang Yu Wu Liming Zhang 《Fluid Dynamics & Materials Processing》 2026年第2期225-252,共28页
This study investigates in-station pressure drop mechanisms in a shale gas gathering system,providing a quantitative basis for flow system optimization.Computational fluid dynamics(CFD)simulations,based on field-measu... This study investigates in-station pressure drop mechanisms in a shale gas gathering system,providing a quantitative basis for flow system optimization.Computational fluid dynamics(CFD)simulations,based on field-measured parameters related to a representative case(a shale gas platform located in Sichuan,China)are conducted to analyze the flow characteristics of specific fittings and manifolds,and to quantify fitting resistance coefficients and manifold inlet interference.The resulting coefficients are integrated into a full-station gathering network model in PipeSim,which,combined with production data,enables evaluation of pressure losses and identification of equivalent pipeline blockages.The results indicate that the resistance coefficients,valid only for fittings under the studied field-specific geometries,are 0.21 for 90◦elbows in the fully open position,0.16 for gate valve passages in the fully open position,and 2.3 for globe valve passages.Manifold interference decreases with lower high-pressure inlet values,whereas inlets farther from the high-pressure side experience stronger disturbances.Interestingly,significant discrepancies between simulated and measured pressure drops reveal partial blockages,corresponding to effective diameter reductions of 65 mm,38 mm,44 mm,38 mm,and 28 mm for Wells 1#,3#,5#,and 6#,respectively. 展开更多
关键词 CFD simulation resistance coefficient correction pressure drop analysis production enhancement
在线阅读 下载PDF
Fusion Correction for China's Domestic Remote Sensing Data of Sea Ice Concentration Using the TransUnet Model
10
作者 ZHAO Chunxiao YANG Yanrui +1 位作者 ZHU Guocan ZHU Hongchun 《Journal of Ocean University of China》 2026年第1期106-122,共17页
The rapid melting of Arctic sea ice poses significant risks to the safety of shipping routes.Accurate remote sensing data on sea ice concentration(SIC)is crucial for effective route planning of ships and ensuring navi... The rapid melting of Arctic sea ice poses significant risks to the safety of shipping routes.Accurate remote sensing data on sea ice concentration(SIC)is crucial for effective route planning of ships and ensuring navigational safety.Despite the availability of numerous SIC products in China,these datasets still lag behind mainstream international products in terms of data accuracy,spatiotemporal resolution,and time span.To enhance the accuracy of China's domestic SIC remote sensing data,this study used the SIC data derived from the passive microwave remote sensing dataset provided by the University of Bremen(BRM-SIC)as a reference to conduct a comprehensive evaluation and analysis of two additional SIC datasets:the dataset derived from the microwave radiation imager(MWRI)aboard the FY-3D satellite,provided by the National Satellite Meteorological Center(FY-SIC),and the dataset obtained through the DT-ASI algorithm from the microwave imager of the FY-3D satellite,provided by Ocean University of China(OUC-SIC).Based on the evaluation results,a TransUnet fusion correction model was developed.The performance of this model was then compared against Ordinary Least Squares(OLS),Random Forest(RF),and UNet correction models,through spatial and temporal analyses.Results indicate that,compared to FY-SIC data,the RMSE of the OUC-SIC data and the standard data is reduced by24.245%,while the R is increased by 12.516%.Overall,the accuracy of OUC-SIC data is superior to that of FY-SIC data.During the research period(2020–2022),the standard deviation(SD)and coefficient of variation(CV)of OUC-SIC were 3.877%and 10.582%,respectively,while those for FY-SIC were 7.836%and 7.982%,respectively.In the study area,compared with OUC-SIC data,FYSIC data exhibited a larger standard deviation of deviation and a smaller coefficient of variation of deviation across most sea areas.These results indicate that the OUC-SIC data exhibit better temporal and spatial stability,whereas the FY-SIC data show stronger relative dimensionless stability.Among the four correction models,all showed improvements over the original,unfused corrected data.The fusion corrections using the OLS,RF,UNet,and TransUnet models reduced RMSE by 5.563%,14.601%,42.927%,and48.316%,respectively.Correspondingly,R increased by 0.463%,1.176%,3.951%,and 4.342%,respectively.Among these models,TransUnet performed the best,effectively integrating the advantages of FY-SIC and OUC-SIC data and notably improving the overall accuracy and spatiotemporal stability of SIC data. 展开更多
关键词 sea ice concentration quality assessment fusion correction Trans Unet model
在线阅读 下载PDF
Diurnal Bias Correction of FY-4B AGRI Water Vapor Channels with Time-Shifted Solar Elevation Angle
11
作者 SONG Jia-yun HAN Wei +1 位作者 SUN Hao-fei YANG Yun-fan 《Journal of Tropical Meteorology》 2026年第1期19-32,共14页
The infrared channels of the FY-4B advanced geosynchronous radiation imagers(AGRI) play a crucial role in temperature and humidity analyses for mesoscale numerical weather prediction, particularly in enhancing the ini... The infrared channels of the FY-4B advanced geosynchronous radiation imagers(AGRI) play a crucial role in temperature and humidity analyses for mesoscale numerical weather prediction, particularly in enhancing the initial field quality and the forecasting accuracy of the model. This study assimilated FY-4B AGRI data into the CMA-MESO model and analyzed the bias characteristics and correction methods. Analysis of the AGRI data revealed a clear diurnal variation in the bias, which was positively correlated with the solar elevation angle. However, the diurnal variation in the bias lagged behind the solar elevation angle, likely owing to temperature changes and delayed instrument responses resulting from solar radiation. To address this issue, we propose a correction method that utilizes the solar elevation angle after an optimal time shift. Using the time-shifted solar elevation angle as a predictor effectively reduces the diurnal variation in bias and significantly improves the correction effect. This approach provides theoretical support for the assimilation of FY-4B AGRI data into mesoscale numerical weather predictions, thereby enhancing the reliability of the assimilation results. 展开更多
关键词 FY-4B AGRI bias correction diurnal variation solar elevation angle
在线阅读 下载PDF
Memristor-based analog noise correction for infrared sensors
12
作者 Xiao Huang Peiwen Tong +4 位作者 Qingjiang Li Tuo Ma Shuo Han Wei Wang Yi Sun 《Chinese Physics B》 2026年第2期630-638,共9页
Sensor noise is a critical factor that degrades the performance of image processing systems.In traditional computing systems,noise correction is implemented in the digital domain,resulting in redundant latency and pow... Sensor noise is a critical factor that degrades the performance of image processing systems.In traditional computing systems,noise correction is implemented in the digital domain,resulting in redundant latency and power consumption overhead in the analog-to-digital conversion.In this work,we propose an analog-domain image correction architecture based on a proposed small-scale UNet,which implements a compact noise correction network within a one-transistor-one-memristor(1T1R)array.The statistical non-idealities of the fabricated 1T1R array(e.g.,device variability)are rigorously incorporated into the network's training and inference simulations.This correction network architecture leverages memristors for conducting multiply-accumulate operations aimed at rectifying non-uniform noise,defective pixels(stuck-at-bright/dark),and exposure mismatch.Compared to systems without correction,the proposed architecture achieves up to 50.13%improvement in recognition accuracy while demonstrating robust tolerance to memristor device-level errors.The proposed system achieves a 2.13-fold latency reduction and three orders of magnitude higher energy efficiency compared to conventional architecture.This work establishes a new paradigm for advancing the development of low-power,low-latency,and high-precision image processing systems. 展开更多
关键词 infrared sensor noise MEMRISTOR analog-domain neuromorphic computing correction network one-transistor-one-memristor(1T1R)array
原文传递
Correction to“Prognostic value of preoperative fibrinogen,neutrophil-to-lymphocyte ratio,serum alpha-fetoprotein,and prealbumin for patients with primary liver cancer undergoing transarterial chemoembolization”
13
作者 Qi-Qi Liu Ya-Dong Li +4 位作者 Jia-Xin Chen Lin-Lin Zhang Rong-Chun Guan Wei Zhao Ling-Yu Meng 《World Journal of Gastrointestinal Oncology》 2026年第1期300-301,共2页
Correction to“Liu QQ,Li YD,Chen JX,Zhang LL,Guan RC,Zhao W,Meng LY.Prognostic value of preoperative fibrinogen,neutrophil-to-lymphocyte ratio,serum alpha-fetoprotein,and prealbumin for patients with primary liver can... Correction to“Liu QQ,Li YD,Chen JX,Zhang LL,Guan RC,Zhao W,Meng LY.Prognostic value of preoperative fibrinogen,neutrophil-to-lymphocyte ratio,serum alpha-fetoprotein,and prealbumin for patients with primary liver cancer undergoing transarterial chemoembolization.World J Gastrointest Oncol 2025;17(6):103198 PMID:40547171 DOI:10.4251/wjgo.v17.i6.103198”.The funding number listed in the"Supported by"section of this article needs to be corrected. 展开更多
关键词 World Journal of Gastrointestinal Oncology correction
暂未订购
Phase aberration correction in ultrasonic phased array non-destructive testing systems
14
作者 赵霞 王召巴 刘宾 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第1期47-52,共6页
Phase aberration correction for medical ultrasound systems has attracted a great deal of attention. Since phased array techniques are now widely employed for industrial non-destructive testing (NDT) applications in ... Phase aberration correction for medical ultrasound systems has attracted a great deal of attention. Since phased array techniques are now widely employed for industrial non-destructive testing (NDT) applications in various fields, the problem of phase aberrations in the process of NDT testing is considered. The technique of cross-covariance for phase aberration correction is presented. The performance of the technique for phase aberration correction is tested by means of echo signals obtained in practical non-destructive testing experiment. The results show that the technique has the better accuracy of phase correction. 展开更多
关键词 ultrasonic phased array non-destructive testing phase aberration correction cross-covariance method
在线阅读 下载PDF
Effects of tube system and data correction for fluctuating pressure test in wind tunnel 被引量:8
15
作者 Xue WANG Xunnian WANG +2 位作者 Xiaobo REN Xiwei YIN Weihua WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2018年第4期710-718,共9页
The accuracy of fluctuating pressure test in wind tunnel is affected by the tube system. By employing contradistinctive experimental method, systematic study was conducted to investigate the effects of the tube system... The accuracy of fluctuating pressure test in wind tunnel is affected by the tube system. By employing contradistinctive experimental method, systematic study was conducted to investigate the effects of the tube system on fluctuating pressure. The analyzed tube system parameters include tube length, inside diameter, curvature, deflection angle, thickness, material, restrictor length,restrictor inside diameter, and restrictor place. It is found that all the tube system parameters mentioned above except tube curvature have non-negligible effects on fluctuating pressure. Based on the research results, test methods were presented for the fluctuating pressure measurement in low-speed wind tunnel, which can obviously improve the data accuracy but not lose test efficiency. The effectiveness of the method is verified by the wind tunnel test. 展开更多
关键词 Data correction Fluctuating pressure Frequency response function Tube system Wind tunnel test
原文传递
Study on element detection and its correction in iron ore concentrate based on a prompt gamma-neutron activation analysis system 被引量:5
16
作者 Long Zhao Xu Xu +6 位作者 Jing-Bin Lu Ya-Lin Gong Xiang-Lin Li Wei Zhang Qing-Min Shang Qing-Feng Song Yan-Feng Li 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第4期44-52,共9页
A prompt gamma-neutron activation analysis(PGNAA) system was developed to detect the iron content of iron ore concentrate. Because of the self-absorption effect of gamma-rays and neutrons, and the interference of chlo... A prompt gamma-neutron activation analysis(PGNAA) system was developed to detect the iron content of iron ore concentrate. Because of the self-absorption effect of gamma-rays and neutrons, and the interference of chlorine in the neutron field, the linear relationship between the iron analytical coefficient and total iron content was poor, increasing the error in the quantitative analysis. To solve this problem, gamma-ray self-absorption compensation and a neutron field correction algorithm were proposed, and the experimental results have been corrected using this algorithm. The results show that the linear relationship between the iron analytical coefficient and total iron content was considerably improved after the correction. The linear correlation coefficients reached 0.99 or more. 展开更多
关键词 PROMPT gamma-neutron activation analysis SELF-ABSORPTION Energy spectrum Compensation correction Iron ORE CONCENTRATE
在线阅读 下载PDF
Accuracy of the half-power bandwidth method with a third-order correction for estimating damping in multi-DOF systems 被引量:4
17
作者 Wang Jinting Lü Dandan +1 位作者 Jin Feng Zhang Chuhan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第1期33-38,共6页
A third-order correction was recently suggested to improve the accuracy of the half-power bandwidth method in estimating the damping of single DOF systems.This paper analyzes the accuracy of the half-power bandwidth m... A third-order correction was recently suggested to improve the accuracy of the half-power bandwidth method in estimating the damping of single DOF systems.This paper analyzes the accuracy of the half-power bandwidth method with the third-order correction in damping estimation for multi-DOF linear systems.Damping ratios in a two-DOF linear system are estimated using its displacement and acceleration frequency response curves,respectively.A wide range of important parameters that characterize the shape of these response curves are taken into account.Results show that the third-order correction may greatly improve the accuracy of the half-power bandwidth method in estimating damping in a two-DOF system.In spite of this,the half-power bandwidth method may significantly overestimate the damping ratios of two-DOF systems in some cases. 展开更多
关键词 half-power bandwidth method third-order correction damping ratio estimation error two-DOF system
在线阅读 下载PDF
Performance analysis and design of MIMO-OFDM system using concatenated forward error correction codes 被引量:3
18
作者 Arun Agarwal Saurabh N.Mehta 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第6期1322-1343,共22页
This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shif... This work investigates the performance of various forward error correction codes, by which the MIMO-OFDM system is deployed. To ensure fair investigation, the performance of four modulations, namely, binary phase shift keying(BPSK), quadrature phase shift keying(QPSK), quadrature amplitude modulation(QAM)-16 and QAM-64 with four error correction codes(convolutional code(CC), Reed-Solomon code(RSC)+CC, low density parity check(LDPC)+CC, Turbo+CC) is studied under three channel models(additive white Guassian noise(AWGN), Rayleigh, Rician) and three different antenna configurations(2×2, 2×4, 4×4). The bit error rate(BER) and the peak signal to noise ratio(PSNR) are taken as the measures of performance. The binary data and the color image data are transmitted and the graphs are plotted for various modulations with different channels and error correction codes. Analysis on the performance measures confirm that the Turbo + CC code in 4×4 configurations exhibits better performance. 展开更多
关键词 bit ERROR rate (BER) convolutional CODE (CC) forward ERROR correction peak signal to noise ratio (PSNR) Turbo CODE
在线阅读 下载PDF
A correction method of encoder bias in satellite laser ranging system 被引量:3
19
作者 Wang Peiyuan Zhu Wei +1 位作者 Zou Tong Guo Tangyong 《Geodesy and Geodynamics》 2013年第3期61-64,共4页
In a satellite laser ranging telescope system, well-aligned encoders of the elevation and azimuth axes are essential for tracking objects. However, it is very difficult and time-consuming to correct the bias between t... In a satellite laser ranging telescope system, well-aligned encoders of the elevation and azimuth axes are essential for tracking objects. However, it is very difficult and time-consuming to correct the bias between the absolute-position indices of the encoders and the astronomical coordinates, especially in the absence of a finder scope for our system. To solve this problem, a method is presented based on the phenomenon that all stars move anti-clockwise around Polaris in the northern hemisphere. Tests of the proposed adjustment procedure in a satellite laser ranging (SLR)system demonstrated the effectiveness and the time saved by using the approach, which greatly facilitates the optimization of a trackin~ svstem. 展开更多
关键词 correction encoder index TELESCOPE satellite laser ranging
原文传递
Ballistic Trajectory Extrapolation and Correction of Firing Precision for Multiple Launch Rocket System 被引量:1
20
作者 ZHA Qicheng RUI Xiaoting +1 位作者 WANG Guoping YU Hailong 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2019年第2期232-241,共10页
The research on multiple launch rocket system(MLRS)is now even more demanding in terms of reducing the time for dynamic calculations and improving the firing accuracy,keeping the cost as low as possible.This study emp... The research on multiple launch rocket system(MLRS)is now even more demanding in terms of reducing the time for dynamic calculations and improving the firing accuracy,keeping the cost as low as possible.This study employs multibody system transfer matrix method(MSTMM),to model MLRS.The use of this method provides effective and fast calculations of dynamic characteristics,initial disturbance and firing accuracy.Further,a new method of rapid extrapolation of ballistic trajectory of MLRS is proposed by using the position information of radar tests.That extrapolation point is then simulated and compared with the actual results,which demonstrates a good agreement.The closed?loop fire correction method is used to improve the firing accuracy of MLRS at low cost. 展开更多
关键词 multi-body system transfer matrix method(MSTMM) multiple launch ROCKET system(MLRS) dynamic modeling BALLISTIC trajectory EXTRAPOLATION fire correction METHOD
在线阅读 下载PDF
上一页 1 2 136 下一页 到第
使用帮助 返回顶部