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Feedback linearization and equivalent-disturbance compensation control strategy for piezoelectric stage
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作者 Tao Huang Yingbin Wang +3 位作者 Zhihong Luo Huajun Cao Guibao Tao Mingxiang Ling 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第2期49-59,共11页
Piezoelectric stages use piezoelectric actuators and flexure hinges as driving and amplifying mechanisms,respectively.These systems have high positioning accuracy and high-frequency responses,and they are widely used ... Piezoelectric stages use piezoelectric actuators and flexure hinges as driving and amplifying mechanisms,respectively.These systems have high positioning accuracy and high-frequency responses,and they are widely used in various precision/ultra-precision positioning fields.However,the main challenge with these devices is the inherent hysteresis nonlinearity of piezoelectric actuators,which seriously affects the tracking accuracy of a piezoelectric stage.Inspired by this challenge,in this work,we developed a Hammerstein model to describe the hysteresis nonlinearity of a piezoelectric stage.In particular,in our proposed scheme,a feedback-linearization algorithm is used to eliminate the static hysteresis nonlinearity.In addition,a composite controller based on equivalent-disturbance compensation was designed to counteract model uncertainties and external disturbances.An analysis of the stability of a closed-loop system based on this feedback-linearization algorithm and composite controller was performed,and this was followed by extensive comparative experiments using a piezoelectric stage developed in the laboratory.The experimental results confirmed that the feedback-linearization algorithm and the composite controller offer improved linearization and trajectory-tracking performance. 展开更多
关键词 Piezoelectric stage Hysteresis nonlinearity Feedback linearization Equivalent-disturbance compensation
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Trajectory compensation for multi-robot coordinated lifting system considering elastic catenary of the rope
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作者 ZHAO Xiangtang ZHAO Zhigang +2 位作者 SU Cheng MENG Jiadong WANG Baoxi 《High Technology Letters》 EI CAS 2024年第3期252-262,共11页
The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the... The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible coupling.The deformation of the flexible rope causes errors in the movement trajectory of the lifting system.Based on the kinematic and dynamic analysis of the lifting system,the elastic catenary mod-el considering the elasticity and mass of the flexible rope is established,and the effect of the deform-ation of the flexible rope on the position and posture of the suspended object is analyzed.According to the deformation of flexible rope,a real-time trajectory compensation method is proposed based on the compensation principle of position and posture.Under the lifting task of the low-speed move-ment,this is compared with that of the system which neglects the deformation of the flexible rope.The trajectoy of the lifting system considering the deformation of flexible rope.The results show that the mass and elasticity of the flexible rope can not be neglected.Meanwhile,the proposed trajectory compensation method can improve the movement accuracy of the lifting system,which verifies the ef-fectiveness of this compensation method.The research results provide the basis for trajectory plan-ning and coordinated control of the lifting system。 展开更多
关键词 multi-robot lifting system deformation of flexible rope elastic catenary model compensation principle of position and posture trajectory compensation
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Optical frequency transfer link with remote site compensation
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作者 Qi Zang Xiang Zhang +9 位作者 Xue Deng Qian Zhou Dan Wang Yucan Zhang Jing Gao Dongdong Jiao Guanjun Xu Tao Liu Ruifang Dong Shougang Zhang 《Chinese Optics Letters》 SCIE EI CAS CSCD 2024年第9期68-73,共6页
In this paper,we present a remote time-base-free technique for a coherent optical frequency transfer system via fiber.At the remote site,the thermal noise of the optical components is corrected along with the link pha... In this paper,we present a remote time-base-free technique for a coherent optical frequency transfer system via fiber.At the remote site,the thermal noise of the optical components is corrected along with the link phase noise caused by environmental effects.In this system,a 1×2 acousto-optic modulator(AOM)is applied at the remote site,with the first light being used to eliminate the noise of the remote time base and interface with remote users while the zeroth light is used to establish an active noise canceling loop.With this technique,a 10 MHz commercial oscillator,used as a time base at the remote site,does not contribute to the noise of the transferred signal.An experimental system is constructed using a 150 km fiber spool to validate the proposed technique.After compensation,the overlapping Allan deviation of the transfer link is 7.42×10^(-15)at 1 s integration time and scales down to 1.07×10^(-18)at 10,000 s integration time.The uncertainty of the transmitted optical frequency is on the order of a few 10-19.This significantly reduces the time-base requirements and costs for multi-user applications without compromising transfer accuracy.Meanwhile,these results show great potential for transferring ultra-stable optical frequency signals to remote sites,especially for point-to-multi-users. 展开更多
关键词 optical frequency measurement remote site compensation ultra-stable laser fiber network
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Compensation modification of plastic gear tooth profile considering meshing deformation
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作者 Mingyong LIU Yaole SONG +2 位作者 Xinguang HAN Jun HU Chunai YAN 《Frontiers of Mechanical Engineering》 SCIE CSCD 2024年第5期111-128,共18页
The plastic gear is widely used in agricultural equipment,electronic products,aircraft,and other fields because of its light weight,corrosion resistance,and self-lubrication ability.However,it has a limited range of w... The plastic gear is widely used in agricultural equipment,electronic products,aircraft,and other fields because of its light weight,corrosion resistance,and self-lubrication ability.However,it has a limited range of working conditions due to the low modulus and thermal deformation of the material,especially in high-speed and heavy-duty situations.A compensation modification method(CMM)is proposed in this paper to restrain the heat production of the plastic gear tooth surface by considering the meshing deformation,and the corresponding modification formulas are derived.Improving the position of the maximum contact pressure(CP)and the relative sliding velocity(RSV)of the tooth surface resulted in a 30%lower steady-state temperature rise of the modified plastic gear tooth surface than that of the unmodified plastic gear.Meanwhile,the temperature rise of plastic gear with CMM is reduced by 19%compared with the traditional modification of removal material.Then,the influences of modification index and the segment number of modification on the meshing characteristics of plastic gear with CMM are discussed,such as maximum CP and steadystate temperature rise,RSV,transmission error,meshing angle,and contact ratio.A smaller segment number and modification index are beneficial to reduce the temperature rise of plastic gear with CMM.Finally,an experiment is carried out to verify the theoretical analysis model. 展开更多
关键词 plastic gear compensation modification meshing deformation temperature rise tooth profile
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Case study on the mechanics of NPR anchor cable compensation for large deformation tunnel in soft rock in the Transverse Mountain area,China
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作者 LI Yong ZHENG Jing +3 位作者 HUO Shu-sen WANG Feng-nian HE Man-chao TAO Zhi-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2054-2069,共16页
A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced duri... A study was conducted to analyze the deformation mechanism of strongly weathered quartz schist in the Daliangshan Tunnel,located in the western Transverse Mountain area.A large deformation problem was experienced during the tunnel construction.To mitigate this problem,a support system was designed incorporating negative Poisson ratio(NPR)anchor cables with negative Poisson ratio effect.Physical model experiments,field experiments,and numerical simulation experiments were conducted to investigate the compensation mechanical behavior of NPR anchor cables.The large deformations of soft rocks in the Daliangshan Tunnel are caused by a high ground stress,a high degree of joint fracture development,and a high degree of surrounding rock fragmentation.A compensation mechanics support system combining long and short NPR anchor cables was suggested to provide sufficient counter-support force(approximately 350 kN)for the surrounding rock inside the tunnel.Comparing the NPR anchor cable support system with the original support system used in the Daliangshan tunnel showed that an NPR anchor cable support system,combining cables of 6.3 m and 10.3 m in length,effectively prevented convergence of surrounding rock deformation,and the integrated settlement convergence value remained below 300 mm.This study provides an effective scientific basis for resolving large deformation problems in deeply buried soft rocks in western transverse mountain areas. 展开更多
关键词 soft rock large deformation NPR anchor cable physical model numerical simulation compensation mechanics
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Application of excavation compensation method for enhancing stability and efficiency in shallow large-span rock tunnels
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作者 BIAN Wen-hui YANG Jun +2 位作者 ZHU Chun WANG Ke-xue XU Dong-ming 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第9期3242-3263,共22页
Engineering shallow,large-span rock tunnels challenges deformation control and escalates construction costs.This study investigates the excavation compensation method(ECM)and its associated technologies to address the... Engineering shallow,large-span rock tunnels challenges deformation control and escalates construction costs.This study investigates the excavation compensation method(ECM)and its associated technologies to address these issues.Utilizing five key technologies,the ECM effectively modulates radial stress post-excavation,redistributes stress in the surrounding rock,and eliminates tensile stress at the excavation face.Pre-tensioning measures further enhance the rock’s residual strength,establishing a new stability equilibrium.Field tests corroborate the method’s effectiveness,demonstrating a crown settlement reduction of 3–8 mm,a nearly 50%decrease compared to conventional construction approaches.Additionally,material consumption and construction duration were reduced by approximately 30%–35%and 1.75 months per 100 m,respectively.Thus,the ECM represents a significant innovation in enhancing the stability and construction efficiency of large-span rock tunnels,marking a novel contribution to the engineering field. 展开更多
关键词 excavation compensation method rocky tunnels shallow spanning tunnels tunnel support field test
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Ultrahigh spatiotemporal resolution beam signal reconstruction with bunch phase compensation
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作者 You-Ming Deng Yong-Bin Leng +2 位作者 Xing-Yi Xu Jian Chen Yi-Mei Zhou 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第5期99-108,共10页
Various electromagnetic signals are excited by the beam in the acceleration and beam-diagnostic elements of a particle accelerator.It is important to obtain time-domain waveforms of these signals with high temporal re... Various electromagnetic signals are excited by the beam in the acceleration and beam-diagnostic elements of a particle accelerator.It is important to obtain time-domain waveforms of these signals with high temporal resolution for research,such as the study of beam–cavity interactions and bunch-by-bunch parameter measurements.Therefore,a signal reconstruction algorithm with ultrahigh spatiotemporal resolution and bunch phase compensation based on equivalent sampling is proposed in this paper.Compared with traditional equivalent sampling,the use of phase compensation and setting the bunch signal zero-crossing point as the time reference can construct a more accurate reconstructed signal.The basic principles of the method,simulation,and experimental comparison are also introduced.Based on the beam test platform of the Shanghai Synchrotron Radiation Facility(SSRF)and the method of experimental verification,the factors that affect the reconstructed signal quality are analyzed and discussed,including the depth of the sampled data,quantization noise of analog-to-digital converter,beam transverse oscillation,and longitudinal oscillation.The results of the beam experiments show that under the user operation conditions of the SSRF,a beam excitation signal with an amplitude uncertainty of 2%can be reconstructed. 展开更多
关键词 Turn-by-turn bunch phase compensation technique Equivalent sampling Signal reconstruction algorithm Ultrahigh spatiotemporal resolution SSRF
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Excavation compensation and bolt support for a deep mine drift
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作者 Longji Guo Zhigang Tao +1 位作者 Manchao He Massimo Coli 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期3206-3220,共15页
To overcome large deformation of deep phosphate rock roadways and pillar damage,a new type of constant-resistance large-deformation negative Poisson’s ratio(NPR)bolt that can withstand a high prestress of at least 13... To overcome large deformation of deep phosphate rock roadways and pillar damage,a new type of constant-resistance large-deformation negative Poisson’s ratio(NPR)bolt that can withstand a high prestress of at least 130 KN was developed.In the conducted tests,the amount of deformation was 200-2000 mm,the breaking force reached 350 KN,and a high constant-resistance pre-stress was maintained during the deformation process.A stress compensation theory of phosphate rock excavation based on NPR bolts is proposed together with a balance system for bolt compensation of the time-space effect and high NPR pre-stress.Traditional split-set rock bolts are unable to maintain the stability of roadway roofs and pillars.To verify the support effect of the proposed bolt,field tests were conducted using both the proposed NPR bolts and split-set rock bolts as support systems on the same mining face.In addition,the stress compensation mechanism of roadway mining was simulated using the particle flow code in three dimensions(PFC^(3D))-fast Lagrangian analysis of continua(FLAC^(3D))particle-flow coupling numerical model.On-site monitoring and numerical simulations showed that the NPR excavation compensation support scheme effectively improves the stress state of the bolts and reduces the deformation of the surrounding rock.Compared to the original support scheme,the final deformation of the surrounding rock was reduced by approximately 70%.These results significantly contribute to domestic and foreign research on phosphate-rock NPR compensation support technology,theoretical systems,and engineering practices,and further promote technological innovation in the phosphate rock mining industry. 展开更多
关键词 Deep phosphate rock NPR bolt Split-set rock bolt PFC3D-FLAC3D compensation support
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Study on thermal decomposition kinetics of azobenzene-4,4′-dicarboxylic acid by using compensation parameter method and nonlinear fitting evaluation
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作者 Shuyi Shen Song Guo +1 位作者 Sining Chen Jinhua Zhao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期269-279,共11页
Recently,azobenzene-4,4'-dicarboxylic acid(ADCA)has been produced gradually for use as an organic synthesis or pharmaceutical intermediate due to its eminent performance.With large quantities put into application ... Recently,azobenzene-4,4'-dicarboxylic acid(ADCA)has been produced gradually for use as an organic synthesis or pharmaceutical intermediate due to its eminent performance.With large quantities put into application in the future,the thermal stability of this substance during storage,transportation,and use will become quite important.Thus,in this work,the thermal decomposition behavior,thermal decomposition kinetics,and thermal hazard of ADCA were investigated.Experiments were conducted by using a SENSYS evo DSC device.A combination of differential iso-conversion method,compensation parameter method,and nonlinear fitting evaluation were also used to analyze thermal kinetics and mechanism of ADCA decomposition.The results show that when conversion rate α increases,the activation energies of ADCA's first and main decomposition peaks fall.The amount of heat released during decomposition varies between 182.46 and 231.16 J·g^(-1).The proposed kinetic equation is based on the Avrami-Erofeev model,which is consistent with the decomposition progress.Applying the Frank-Kamenetskii model,a calculated self-accelerating decomposition temperature of 287.0℃is obtained. 展开更多
关键词 Azobenzene-4 4′-dicarboxylic acid Thermal decomposition behavior Kinetic mechanism Thermal hazard evaluation compensation parameter effect
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Research on Anti-Fluctuation Control of Winding Tension System Based on Feedforward Compensation
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作者 Yujie Duan Jianguo Liang +4 位作者 Jianglin Liu Haifeng Gao Yinhui Li Jinzhu Zhang Xinyu Wen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1239-1261,共23页
In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension control.In order to effectively reduce the influence of these problems on the tens... In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension control.In order to effectively reduce the influence of these problems on the tension output,this paper proposed a tension fluctuation rejection strategy based on feedforward compensation.In addition to the bias harmonic curve of the unknown state,the tension fluctuation also contains the influence of bounded noise.A tension fluctuation observer(TFO)is designed to cancel the uncertain periodic signal,in which the frequency generator is used to estimate the critical parameter information.Then,the fluctuation signal is reconstructed by a third-order auxiliary filter.The estimated signal feedforward compensates for the actual tension fluctuation.Furthermore,a time-varying parameters fractional-order PID controller(TPFOPID)is realized to attenuate the bounded noise in the fluctuation.Finally,TPFOPID is enhanced by TFO and applied to control a tension control system considering multi-source disturbances.The stability of the method is analyzed by using the Lyapunov theorem.Finally,numerical simulations verify that the proposed scheme improves the tracking ability and robustness of the system in response to tension fluctuations. 展开更多
关键词 Constant tension control anti-fluctuation strategy tension fluctuation observer time-varying parameters fractional-order PID controller feedforward compensate
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Force Compensation Control for Electro-Hydraulic Servo System with Pump-Valve Compound Drive via QFT-DTOC
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作者 Kaixian Ba Yuan Wang +4 位作者 Xiaolong He Chunyu Wang Bin Yu Yaliang Liu Xiangdong Kong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期228-246,共19页
Each joint of a hydraulic-driven legged robot adopts a highly integrated hydraulic drive unit(HDU),which features a high power-weight ratio.However,most HDUs are throttling-valve-controlled cylinder systems,which exhi... Each joint of a hydraulic-driven legged robot adopts a highly integrated hydraulic drive unit(HDU),which features a high power-weight ratio.However,most HDUs are throttling-valve-controlled cylinder systems,which exhibit high energy losses.By contrast,pump control systems offer a high efficiency.Nevertheless,their response ability is unsatisfactory.To fully utilize the advantages of pump and valve control systems,in this study,a new type of pump-valve compound drive system(PCDS)is designed,which can not only effectively reduce the energy loss,but can also ensure the response speed and response accuracy of the HDUs in robot joints to satisfy the performance requirements of robots.Herein,considering the force control requirements of energy conservation,high precision,and fast response of the robot joint HDU,a nonlinear mathematical model of the PCDS force control system is first introduced.In addition,pressure-flow nonlinearity,friction nonlinearity,load complexity and variability,and other factors affecting the system are considered,and a novel force control method based on quantitative feedback theory(QFT)and a disturbance torque observer(DTO)is designed,which is denoted as QFT-DTOC herein.This method improves the control accuracy and robustness of the force control system,reduces the effect of the disturbance torque on the control performance of the servo motor,and improves the overall force control performance of the system.Finally,experimental verification is performed using the PCDS performance test platform.The experimental results and quantitative data show that the QFT-DTOC proposed herein can significantly improve the force control performance of the PCDS.The relevant force control method can be used as a bottom-control method for the hydraulic servo system to provide a foundation for implementing the top-level trajectory planning of the robot. 展开更多
关键词 Legged robot Pump-valve compound drive system(PCDS) Force compensation control Quantitative feedback theory(QFT) Disturbance torque observer(DTO)
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The Rights to Claim for Industrial Injury Compensation and Tort Compensation are Applicable to the Law:Taking Fu and Li v.a Passenger Transport Company as an Example
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作者 Li Guo 《Journal of Contemporary Educational Research》 2024年第1期154-158,共5页
In the case of third-party tort,due to the lack of clear and detailed provisions on the treatment of employee’s industrial injury insurance payment and tort damage compensation,the judicial theory and practice have b... In the case of third-party tort,due to the lack of clear and detailed provisions on the treatment of employee’s industrial injury insurance payment and tort damage compensation,the judicial theory and practice have brought many disputes.Through combing the current relevant laws and regulations,it can be found that the application of the two systems will lead to the overlapping of industrial injury compensation.This paper analyzes the problems arising from the concurrence of industrial injury compensation and tort compensation using the case of Fu and Li v.a passenger transport company,and puts forward some ideas and suggestions on how to improve the settlement measures of such cases. 展开更多
关键词 Industrial injury compensation and tort compensation Double indemnity
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Problems and Countermeasures to Improve Clinical Trial Participants’Compensation Rights in China
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作者 Yang Xiuqiao Wen Ping +2 位作者 Lin Hong Chen Wenhuan Chen Yuwen 《Asian Journal of Social Pharmacy》 2024年第1期58-63,共6页
Objective To discuss the problems existing in the compensation of Chinese clinical trial participants and propose some suggestions for improving their rights.Methods The literature related to the participants’right t... Objective To discuss the problems existing in the compensation of Chinese clinical trial participants and propose some suggestions for improving their rights.Methods The literature related to the participants’right to compensation at home and abroad was searched to study the inadequacy of the compensation right for clinical trial participants in China from four aspects:insurance system,principle of attribution,legal relationship and compensation regulations.Then,some suggestions to improve the participants’right to compensation were proposed.Results and Conclusion China lacks clear legal norms for participants’right to compensation.There are problems such as unclear insurance rules and compensation rules,unclear contractual relationships between parties to clinical trials,and no laws and regulations to rely on for attribution and compensation.China should issue regulatory guidelines related to the right to compensation of participants in clinical trials,so that all parties in clinical trials can have rules to follow if there is the occurrence of injury,which can better protect the rights and interests of the participants. 展开更多
关键词 clinical trial PARTICIPANT compensation right
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The Translation of Chinese Literature under the Theory of Translation Compensation
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作者 WANG Rong 《Philosophy Study》 2024年第1期9-15,共7页
In order to promote the exchange of Chinese culture with foreign countries,translators bear an important mission in the process of cross-cultural communication.Although there are cultural differences,we can achieve cu... In order to promote the exchange of Chinese culture with foreign countries,translators bear an important mission in the process of cross-cultural communication.Although there are cultural differences,we can achieve cultural dissemination and exchange through continuous cultural dialogue.As an important way for foreign scholars to understand the history of the Shang and Zhou Dynasties in China,the translation of historical texts is crucial.Multiple typical cases are selected under the guidance of the translation theory of compensation to use relevant methods or techniques from the three levels of language,culture,and aesthetics to compensate for the loss of Li Xueqin’s The Origin of Ancient Chinese Civilization in English translation proofreading. 展开更多
关键词 translation compensation theory Li Xueqin The Origin of Ancient Chinese Civilization
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Design of Cold-Junction Compensation and Disconnection Detection Circuits of Various Thermocouples and Implementation of Multi-Channel Interfaces Using Them-A Secondary Publication
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作者 Hyeong-Woo Cha 《Journal of Electronic Research and Application》 2024年第1期93-105,共13页
Cold-junction compensation(CJC)and disconnection detection circuit design of various thermocouples(TC)and multi-channel TC interface circuits were designed.The CJC and disconnection detection circuit consists of a CJC... Cold-junction compensation(CJC)and disconnection detection circuit design of various thermocouples(TC)and multi-channel TC interface circuits were designed.The CJC and disconnection detection circuit consists of a CJC semiconductor device,an instrumentation amplifier(IA),two resistors,and a diode for disconnection detection.Based on the basic circuit,a multi-channel interface circuit was also implemented.The CJC was implemented using compensation semiconductor and IA,and disconnection detection was detected by using two resistors and a diode so that IA input voltage became-0.42 V.As a result of the experiment using R-type TC,the error of the designed circuit was reduced from 0.14 mV to 3μV after CJC in the temperature range of 0°C to 1400°C.In addition,it was confirmed that the output voltage of IA was saturated from 88 mV to-14.2 V when TC was disconnected from normal.The output voltage of the designed circuit was 0 V to 10 V in the temperature range of 0°C to 1400°C.The results of the 4-channel interface experiment using R-type TC were almost identical to the CJC and disconnection detection results for each channel.The implemented multi-channel interface has a feature that can be applied equally to E,J,K,T,R,and S-type TCs by changing the terminals of CJC semiconductor devices and adjusting the IA gain. 展开更多
关键词 R-type thermocouple(TC) Cold-junction compensation(CJC) TC disconnection detection Multi-channel interface circuit Sensor interface
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Validation of the albumin-bilirubin score for identifying decompensation risk in patients with compensated cirrhosis 被引量:3
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作者 Huttakan Navadurong Kessarin Thanapirom +4 位作者 Salisa Wejnaruemarn Thaninee Prasoppokakorn Roongruedee Chaiteerakij Piyawat Komolmit Sombat Treeprasertsuk 《World Journal of Gastroenterology》 SCIE CAS 2023年第32期4873-4882,共10页
BACKGROUND The albumin-bilirubin(ALBI)score is an index of liver function recently developed to assess prognosis in patients with hepatocellular carcinoma(HCC).It can detect small changes in liver dysfunction and has ... BACKGROUND The albumin-bilirubin(ALBI)score is an index of liver function recently developed to assess prognosis in patients with hepatocellular carcinoma(HCC).It can detect small changes in liver dysfunction and has been successfully applied to the prediction of survival in patients with non-malignant liver diseases of various etiologies.AIM To investigate the ALBI score for identifying decompensation risk at the 3-year follow-up in patients with compensated cirrhosis.METHODS One-hundred and twenty-three patients with compensated cirrhosis without HCC in King Chulalongkorn Memorial Hospital diagnosed by imaging were retrospectively enrolled from January 2016 to December 2020.A total of 113 patients(91.9%)had Child A cirrhosis with a median model for end-stage liver disease(MELD)score of less than 9.Baseline clinical and laboratory variables and decompensation events were collected.The ALBI score was calculated and validated to classify decompensation risk into low-,middle-,and high-risk groups using three ALBI grade ranges(ALBI grade 1:≤-2.60;grade 2:>-2.60 but≤-1.39;grade 3:>-1.39).Decompensation events were defined as ascites development,variceal bleeding,or grade 3 or 4 hepatic encephalopathy.RESULTS Among 123 cirrhotic patients enrolled,13.8%(n=17)developed decompensating events at a median time of 25[95%confidence interval(CI):17-31]mo.Median baseline ALBI score in compensated cirrhosis was significantly lower than that of patients who developed decompensation events[-2.768(-2.956 to-2.453)vs-2.007(-2.533 to-1.537);P=0.01].Analysis of decompensation risk at 3 years showed that ALBI score had a time-dependent area under the curve(tAUC)of 0.86(95%CI:0.78-0.92),which was significantly better than that of ALBI-Fibrosis-4(ALBI-FIB4)score(tAUC=0.77),MELD score(tAUC=0.66),Child-Pugh score(tAUC=0.65),and FIB-4 score(tAUC=0.48)(P<0.05 for all).The 3-year cumulative incidence of decompensation was 3.1%,22.6%,and 50%in the low-,middle-,and high-risk groups,respectively(P<0.001).The odds ratio for decompensation in patients of the high-risk group was 23.33(95%CI:3.88-140.12,P=0.001).CONCLUSION The ALBI score accurately identifies decompensation risk at the 3-year follow-up in patients with compensated cirrhosis.Those cirrhotic patients with a high-risk grade of ALBI score showed a 23 times greater odds of decompensation. 展开更多
关键词 Albumin-bilirubin score compensated cirrhosis Hepatic decompensation risk
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Excavation compensation theory and supplementary technology system for large deformation disasters 被引量:4
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作者 Manchao He Qiru Sui Zhigang Tao 《Deep Underground Science and Engineering》 2023年第2期105-128,共24页
Given the challenges in managing large deformation disasters in energy engineering,traffic tunnel engineering,and slope engineering,the excavation compensation theory has been proposed for large deformation disasters ... Given the challenges in managing large deformation disasters in energy engineering,traffic tunnel engineering,and slope engineering,the excavation compensation theory has been proposed for large deformation disasters and the supplementary technology system is developed accordingly.This theory is based on the concept that“all destructive behaviors in tunnel engineering originate from excavation.”This paper summarizes the development of the excavation compensation theory in five aspects:the“theory,”“equipment,”“technology,”the design method with large deformation mechanics,and engineering applications.First,the calculation method for compensation force has been developed based on this theory,and a comprehensive large deformation disaster control theory system is formed.Second,a negative Poisson's ratio anchor cable with high preload,large deformation,and super energy absorption characteristics has been independently developed and applied to large deformation disaster control.An intelligent tunnel monitoring and early warning cloud platform system are established for remote monitoring and early warning system of Newton force in landslide geological hazards.Third,the double gradient advance grouting technology,the two-dimensional blasting technology,and the integrated Newton force monitoring--early warning--control technology are developed for different engineering environments.Finally,some applications of this theory in China's energy,traffic tunnels,landslide,and other field projects have been analyzed,which successfully demonstrates the capability of this theory in large deformation disaster control. 展开更多
关键词 energy engineering excavation compensation large deformation NPR anchor cable slope engineering traffic tunnel engineering
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Coherent range-dependent map-drift algorithm for improving SAR motion compensation 被引量:1
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作者 ZHANG Man WANG Guanyong +1 位作者 WEI Feiming JIN Xue 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第1期47-55,共9页
Synthetic aperture radar(SAR) is usually sensitive to trajectory deviations that cause serious motion error in the recorded data. In this paper, a coherent range-dependent mapdrift(CRDMD) algorithm is developed to acc... Synthetic aperture radar(SAR) is usually sensitive to trajectory deviations that cause serious motion error in the recorded data. In this paper, a coherent range-dependent mapdrift(CRDMD) algorithm is developed to accommodate the range-variant motion errors. By utilizing the algorithm as an estimate core, robust motion compensation strategy is proposed for unmanned aerial vehicle(UAV) SAR imagery. CRDMD outperforms the conventional map-drift algorithms in both accuracy and efficiency. Real data experiments show that the proposed approach is appropriate for precise motion compensation for UAV SAR. 展开更多
关键词 synthetic aperture radar(SAR) motion compensation(MOCO) coherent map-drift(CMD) range-variant
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A high frequency vibration compensation approach for ultrahigh resolution SAR imaging based on sinusoidal frequency modulation Fourier-Bessel transform 被引量:1
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作者 CHEN Siyu WANG Yong CAO Rui 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第4期894-905,共12页
Ultrahigh resolution synthetic aperture radar(SAR)imaging for ship targets is significant in SAR imaging,but it suffers from high frequency vibration of the platform,which will induce defocus into SAR imaging results.... Ultrahigh resolution synthetic aperture radar(SAR)imaging for ship targets is significant in SAR imaging,but it suffers from high frequency vibration of the platform,which will induce defocus into SAR imaging results.In this paper,a novel compensation method based on the sinusoidal frequency modulation Fourier-Bessel transform(SFMFBT)is proposed,it can estimate the vibration errors,and the phase shift ambiguity can be avoided via extracting the time frequency ridge consequently.By constructing the corresponding compensation function and combined with the inverse SAR(ISAR)technique,well-focused imaging results can be obtained.The simulation imaging results of ship targets demonstrate the validity of the proposed approach. 展开更多
关键词 synthetic aperture radar(SAR) high frequency vibration compensation sinusoidal frequency modulation FourierBessel transform(SFMFBT)
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Research on color image matching method based on feature point compensation in dark light environment 被引量:1
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作者 唐华鹏 QIN Danyang +2 位作者 YAN Mengying YANG Jiaqiang ZHANG Gengxin 《High Technology Letters》 EI CAS 2023年第1期78-86,共9页
Image matching refers to the process of matching two or more images obtained at different time,different sensors or different conditions through a large number of feature points in the image.At present,image matching ... Image matching refers to the process of matching two or more images obtained at different time,different sensors or different conditions through a large number of feature points in the image.At present,image matching is widely used in target recognition and tracking,indoor positioning and navigation.Local features missing,however,often occurs in color images taken in dark light,making the extracted feature points greatly reduced in number,so as to affect image matching and even fail the target recognition.An unsharp masking(USM)based denoising model is established and a local adaptive enhancement algorithm is proposed to achieve feature point compensation by strengthening local features of the dark image in order to increase amount of image information effectively.Fast library for approximate nearest neighbors(FLANN)and random sample consensus(RANSAC)are image matching algorithms.Experimental results show that the number of effective feature points obtained by the proposed algorithm from images in dark light environment is increased,and the accuracy of image matching can be improved obviously. 展开更多
关键词 dark light environment unsharp masking(USM) denoising model feature point compensation fast library for approximate nearest neighbor(FLANN) random sample consensus(RANSAC)
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