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Hemogram-derived ratios as prognostic markers for major adverse cardiovascular events in patients with non-ST-segment elevation myocardial infarction
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作者 Emir Bećirović Minela Bećirović +10 位作者 SabinaŠegalo Amir Bećirović Semir Hadžić Kenana Ljuca Emsel Papić Lamija Ferhatbegović Malik Ejubović Amira JagodićEjubović Amila Kovčić ArminŠljivo Emir Begagić 《World Journal of Methodology》 2025年第2期125-136,共12页
BACKGROUND Non-ST segment elevation myocardial infarction(NSTEMI)poses significant challenges in clinical management due to its diverse outcomes.Understanding the prognostic role of hematological parameters and derive... BACKGROUND Non-ST segment elevation myocardial infarction(NSTEMI)poses significant challenges in clinical management due to its diverse outcomes.Understanding the prognostic role of hematological parameters and derived ratios in NSTEMI patients could aid in risk stratification and improve patient care.AIM To evaluate the predictive value of hemogram-derived ratios for major adverse cardiovascular events(MACE)in NSTEMI patients,potentially improving clinical outcomes.METHODS A prospective,observational cohort study was conducted in 2021 at the Internal Medicine Clinic of the University Hospital in Tuzla,Bosnia and Herzegovina.The study included 170 patients with NSTEMI,who were divided into a group with MACE and a control group without MACE.Furthermore,the MACE group was subdivided into lethal and non-lethal groups for prognostic analysis.Alongside hematological parameters,an additional 13 hematological-derived ratios(HDRs)were monitored,and their prognostic role was investigated.RESULTS Hematological parameters did not significantly differ between non-ST segment elevation myocardial infarction(NSTEMI)patients with MACE and a control group at T1 and T2.However,significant disparities emerged in HDRs among NSTEMI patients with lethal and non-lethal outcomes post-MACE.Notably,neutrophil-to-lymphocyte ratio(NLR)and platelet-to-lymphocyte ratio(PLR)were elevated in lethal outcomes.Furthermore,C-reactive protein-to-lymphocyte ratio(CRP/Ly)at T1(>4.737)demonstrated predictive value[odds ratio(OR):3.690,P=0.024].Both NLR at T1(>4.076)and T2(>4.667)emerged as significant predictors,with NLR at T2 exhibiting the highest diagnostic performance,as indicated by an area under the curve of 0.811(95%CI:0.727-0.859)and OR of 4.915(95%CI:1.917-12.602,P=0.001),emphasizing its important role as a prognostic marker.CONCLUSION This study highlights the significant prognostic value of hemogram-derived indexes in predicting MACE among NSTEMI patients.During follow-up,NLR,PLR,and CRP/Ly offer important insights into the inflammatory processes underlying cardiovascular events. 展开更多
关键词 Hemogram-derived ratios Prognostic markers Neutrophil-to-lymphocyte ratio Myocardial infarction
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Trends of alkaline phosphatase to prealbumin ratio in patients with hepatitis B linked to hepatocellular carcinoma development
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作者 Wen-Chong Zhen Jing Sun +8 位作者 Xue-Ting Bai Qian Zhang Zi-Han Li Yi-Xin Zhang Rong-Xuan Xu Wei Wu Zhi-Han Yao Chun-Wen Pu Xiao-Feng Li 《World Journal of Gastroenterology》 SCIE CAS 2025年第2期42-51,共10页
BACKGROUND Chronic hepatitis B often progresses silently toward hepatocellular carcinoma(HCC),a leading cause of mortality worldwide.Early detection of HCC is crucial,yet challenging.AIM To investigate the role of dyn... BACKGROUND Chronic hepatitis B often progresses silently toward hepatocellular carcinoma(HCC),a leading cause of mortality worldwide.Early detection of HCC is crucial,yet challenging.AIM To investigate the role of dynamic changes in alkaline phosphatase to prealbumin ratio(APR)in hepatitis B progression to HCC.METHODS Data from 4843 patients with hepatitis B(January 2015 to January 2024)were analyzed.HCC incidence rates in males and females were compared using the log-rank test.Data were evaluated using Kaplan–Meier analysis.The Linear Mixed-Effects Model was applied to track the fluctuation of APR levels over time.Furthermore,Joint Modeling of Longitudinal and Survival data was employed to investigate the temporal relationship between APR and HCC risk.RESULTS The incidence of HCC was higher in males.To ensure the model’s normality assumption,this study applied a logarithmic transformation to APR,yielding ratio.Ratio levels were higher in females(t=5.26,P<0.01).A 1-unit increase in ratio correlated with a 2.005-fold higher risk of HCC in males(95%CI:1.653-2.431)and a 2.273-fold higher risk in females(95%CI:1.620-3.190).CONCLUSION Males are more prone to HCC,while females have higher APR levels.Despite no baseline APR link,rising APR indicates a higher HCC risk. 展开更多
关键词 Alkaline phosphatase to prealbumin ratio Chronic hepatitis B patients Hepatocellular carcinoma Retrospective cohort study Linear Mixed-Effect Mode Joint Modelling of Longitudinal and Survival data
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基于改进Ratio统计量的重尾AR(p)时间序列均值变点检验
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作者 张思 刘叶 金浩 《统计与决策》 CSSCI 北大核心 2024年第2期52-57,共6页
文章提出两个改进的Ratio统计量来研究重尾AR(p)时间序列均值变点检验问题,在原假设下推导了统计量的渐近分布,且在备择假设下证明了其一致性。由于重尾指数未知且难以估计,因此结合Wild Bootstrap重抽样方法来确定渐近分布的临界值;在... 文章提出两个改进的Ratio统计量来研究重尾AR(p)时间序列均值变点检验问题,在原假设下推导了统计量的渐近分布,且在备择假设下证明了其一致性。由于重尾指数未知且难以估计,因此结合Wild Bootstrap重抽样方法来确定渐近分布的临界值;在均值变点存在的情形下,给出了变点位置的一致估计量。数值模拟结果表明:统计量的临界值均不受重尾指数和自回归系数的影响,其经验水平和经验势均取得满意的效果;尤其在原假设下,积分型Ratio统计量的经验水平表现出更好的稳健性,而在备择假设下,最值型Ratio统计量则具备更好的显著性。最后,基于一组股票数据,从实际应用角度进一步阐明所提方法的有效性和可行性。 展开更多
关键词 重尾序列 ratio统计量 均值变点 Wild Bootstrap
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P-Δ effect on inelastic displacement ratio spectra for inelastic structures 被引量:3
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作者 翟长海 李宁 +1 位作者 马玉宏 谢礼立 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第1期107-112,共6页
For the evaluation of structures with known ductility demands,the constant-ductility displacement ratio spectra(CDDRS) are particularly useful for providing inelastic displacement ratios to estimate maximum lateral in... For the evaluation of structures with known ductility demands,the constant-ductility displacement ratio spectra(CDDRS) are particularly useful for providing inelastic displacement ratios to estimate maximum lateral inelastic displacement demands from maximum elastic displacement demands.The CDDRS are computed for single-degree-of-freedom systems(SDOF) by considering or ignoring P-Δ effect for different ductility levels when subjected to 344 earthquake ground motions recorded in four site classes.The modified expressions of CDDRS for P-Δ effect are proposed.It is concluded that the P-Δ effect on CDDRS is significant,and the effect increases with the increase of ductility level.In the long-period region,the CDDRS ignoring P-Δ effect almost conforms to the equal-displacement rule.But in the case of higher ductility level,the CDDRS considering P-Δ effect are much higher than 1.0,which do not conform to the equal-displacement rule. 展开更多
关键词 constant-ductility displacement ratio spectra inelastic displacement estimation P-Δ effect ductility level structural periods
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Study on inelastic displacement ratio spectra for near-fault pulse-type ground motions 被引量:2
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作者 翟长海 李爽 +1 位作者 谢礼立 孙亚民 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2007年第4期351-355,共5页
In displacement-based seismic design, inelastic displacement ratio spectra (IDRS) are particularly useful for estimating the maximum lateral inelastic displacement demand of a nonlinear SDOF system from the maximum ... In displacement-based seismic design, inelastic displacement ratio spectra (IDRS) are particularly useful for estimating the maximum lateral inelastic displacement demand of a nonlinear SDOF system from the maximum elastic displacement demand of its counterpart linear elastic SDOF system. In this study, the characteristics of IDRS for near-fault pulse-type ground motions are investigated based on a great number of earthquake ground motions. The influence of site conditions, ratio of peak ground velocity (PGV) to peak ground acceleration (PGA), the PGV, and the maximum incremental velocity (MIV) on IDRS are also evaluated. The results indicate that the effect of near-fault ground motions on IDRS are significant only at periods between 0.2 s - 1.5 s, where the amplification can approach 20%. The PGV/PGA ratio has the most significant influence on IDRS among the parameters considered. It is also found that site conditions only slightly affect the IDRS. 展开更多
关键词 near-fault pulse-type ground motion inelastic displacement ratio spectrum ground motion parameter PGV/PGA site condition
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Inelastic displacement ratio of low-to mid-rise BRBFs designed under variable levels of seismicity 被引量:1
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作者 Hamdy Abou-Elfath Mostafa Ramadan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第3期763-775,共13页
Buckling-restrained braces(BRBs)have shown their capability to provide building structures with stiffness,strength,and ductility.Estimating the seismic drifts of buckling-restrained braced frames(BRBFs)is an important... Buckling-restrained braces(BRBs)have shown their capability to provide building structures with stiffness,strength,and ductility.Estimating the seismic drifts of buckling-restrained braced frames(BRBFs)is an important design step to control structural and non-structural damage.In current practice of seismic design,the estimation of seismic drifts of BRBFs is performed by using empirical calculations that are independent upon either the type of the structural system or the design level of seismicity.In these empirical calculations,the seismic drifts are estimated by amplifying the reduced elastic drifts obtained under design lateral loading with a displacement amplification factor(DAF).The value of DAF is considered equal to the product of the response modification factor R and the inelastic displacement ratioρ.The goal of the current research is to assess the value ofρfor low-to mid-rise BRBFs designed under low and high levels of seismicity.This goal has been achieved by conducting a series of elastic and inelastic time-history analyses pertaining to an ensemble of earthquake records on 3-,6-and 9-story BRBFs.The results indicate that theρ-ratio increases with an increase in design seismic intensity and an increase in experienced inelasticity.The range ofρfor low seismicity designs ranges from 0.63 to 0.9,while for high seismicity designs this range stretches from 0.83 to 1.29.It has been found that the consideration of a generalρ-ratio of 1.0 is a reasonable estimation for the design of the BRBFs considered in this study. 展开更多
关键词 displacement amplification factor inelastic displacement ratio SEISMICITY buckling-restrained brace seismic drift seismic design
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Effect of ground motion duration on inelastic displacement ratio of SDOF systems 被引量:1
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作者 Saman Yaghmaei-Sabegh Sonia Daneshgari 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第2期423-439,共17页
In this paper,the influence of ground motion duration on the inelastic displacement ratio,C_(1),of highly damped SDOF systems is studied.For this purpose,two sets of spectrally equivalent long and short duration groun... In this paper,the influence of ground motion duration on the inelastic displacement ratio,C_(1),of highly damped SDOF systems is studied.For this purpose,two sets of spectrally equivalent long and short duration ground motion records were used in an analysis to isolate the effects of ground motion duration on.The effect of duration was evaluated for observed values of C_(1) by considering six ductility levels,and different damping and post-yield stiffness ratios.A new predictive equation of C_(1) also was developed for long and short duration records.Results of non-linear regression analysis of the current study provide an expression with which to quantify the duration effect.Based on the average values of estimated C_(1) ratios for long duration records divided by C_(1) for a short duration set,it is concluded that the maximum difference between long and short duration records occurs when the damping ratio is 0.3 and the post-yield stiffness ratio is equal to zero. 展开更多
关键词 inelastic displacement ratio long and short duration earthquakes highly damped SDOF systems DUCTILITY
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Lateral displacement of silty clay under cement-fly ash-gravel pile-supported embankments: Analytical consideration and field evidence 被引量:5
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作者 张崇磊 蒋关鲁 +1 位作者 刘先峰 王智猛 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1477-1489,共13页
Based on back analysis of lateral displacements measured in situ by using the analytical solution, a useful method for estimating stress concentration ratio of geosynthetic-reinforced and pile-supported(GRPS) embankme... Based on back analysis of lateral displacements measured in situ by using the analytical solution, a useful method for estimating stress concentration ratio of geosynthetic-reinforced and pile-supported(GRPS) embankments was proposed. In order to validate the proposed method, a full-scale high-speed railway embankment(HSRE) with four instrumented subsections over medium compressibility silty clay was constructed in three stages. The soil profile, construction procedure and monitoring of settlements and lateral displacements of the four test sections were described. The field deformation analysis results show that 1) the combined reinforcement of CFG piles and geosynthetic layer perform well in terms of reducing lateral displacements; 2) the development of lateral displacements lags behind the increase of fill load, which can be attributed to the vertical load transfer mechanism of the pile foundation; and 3) pile length has a dominant effect on the stress distribution proportion between piles and surrounding soils. The comparison between predicted and experimental results suggests that the proposed analytical solution and the back analysis-based method are capable of reasonably estimating the lateral deformation and the stress concentration ratio, respectively, if the appropriate soil elastic modulus is chosen. 展开更多
关键词 piled-supported embankment silty clay lateral displacement field test stress concentration ratio
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A Review on Deterministic Lateral Displacement for Particle Separation and Detection 被引量:4
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作者 Thoriq Salafi Yi Zhang Yong Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2019年第4期353-385,共33页
The separation and detection of particles in suspension are essential for a wide spectrum of applications including medical diagnostics.In this field,microfluidic deterministic lateral displacement(DLD)holds a promise... The separation and detection of particles in suspension are essential for a wide spectrum of applications including medical diagnostics.In this field,microfluidic deterministic lateral displacement(DLD)holds a promise due to the ability of continuous separation of particles by size,shape,deformability,and electrical properties with high resolution.DLD is a passive microfluidic separation technique that has been widely implemented for various bioparticle separations from blood cells to exosomes.DLD techniques have been previously reviewed in 2014.Since then,the field has matured as several physics of DLD have been updated,new phenomena have been discovered,and various designs have been presented to achieve a higher separation performance and throughput.Furthermore,some recent progress has shown new clinical applications and ability to use the DLD arrays as a platform for biomolecules detection.This review provides a thorough discussion on the recent progress in DLD with the topics based on the fundamental studies on DLD models and applications for particle separation and detection.Furthermore,current challenges and potential solutions of DLD are also discussed.We believe that a comprehensive understanding on DLD techniques could significantly contribute toward the advancements in the field for various applications.In particular,the rapid,low-cost,and high-throughput particle separation and detection with DLD have a tremendous impact for point-of-care diagnostics. 展开更多
关键词 Microfluidic DETERMINISTIC LATERAL displacement PARTICLE SEPAratioN PARTICLE DETECTION
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A structural topological optimization method for multi-displacement constraints and any initial topology configuration 被引量:9
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作者 J. H. Rong J. H. Yi 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第5期735-744,共10页
In density-based topological design, one expects that the final result consists of elements either black (solid material) or white (void), without any grey areas. Moreover, one also expects that the optimal topolo... In density-based topological design, one expects that the final result consists of elements either black (solid material) or white (void), without any grey areas. Moreover, one also expects that the optimal topology can be obtained by starting from any initial topology configuration. An improved structural topological optimization method for multidisplacement constraints is proposed in this paper. In the proposed method, the whole optimization process is divided into two optimization adjustment phases and a phase transferring step. Firstly, an optimization model is built to deal with the varied displacement limits, design space adjustments, and reasonable relations between the element stiffness matrix and mass and its element topology variable. Secondly, a procedure is proposed to solve the optimization problem formulated in the first optimization adjustment phase, by starting with a small design space and advancing to a larger deign space. The design space adjustments are automatic when the design domain needs expansions, in which the convergence of the proposed method will not be affected. The final topology obtained by the proposed procedure in the first optimization phase, can approach to the vicinity of the optimum topology. Then, a heuristic algorithm is given to improve the efficiency and make the designed structural topology black/white in both the phase transferring step and the second optimization adjustment phase. And the optimum topology can finally be obtained by the second phase optimization adjustments. Two examples are presented to show that the topologies obtained by the proposed method are of very good 0/1 design distribution property, and the computational efficiency is enhanced by reducing the element number of the design structural finite model during two optimization adjustment phases. And the examples also show that this method is robust and practicable. 展开更多
关键词 Topological optimization displacement constraint Continuum structure Design space adjustment rational approximation material model
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On time-step in structural seismic response analysis under ground displacement/acceleration 被引量:3
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作者 TianYuji~+ and Yang Qingshan~(++) School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China +Associate Professor ++Professor 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2009年第3期341-347,共7页
There are two models in use today to analyze structural responses when subjected to earthquake ground motions, the Displacement Input Model (DIM) and the Acceleration Input Model (AIM). The time steps used in dire... There are two models in use today to analyze structural responses when subjected to earthquake ground motions, the Displacement Input Model (DIM) and the Acceleration Input Model (AIM). The time steps used in direct integration methods for these models are analyzed to examine the suitability of DIM. Numerical results are presented and show that the time-step for DIM is about the same as for AIM, and achieves the same accuracy. This is contrary to previous research that reported that there are several sources of numerical errors associated with the direct application of earthquake displacement loading, and a very small time step is required to define the displacement record and to integrate the dynamic equilibrium equation. It is shown in this paper that DIM is as accurate and suitable as, if not more than, AIM for analyzing the response of a structure to uniformly distributed and spatially varying ground motions. 展开更多
关键词 integration time step multi-supported structure displacement input model acceleration input model spatially varying ground motions
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Microglial displacement of GABAergic synapses has endogenous protective function in generation of complex febrile seizures 被引量:1
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作者 WAN Yu-shan YOU Yi +5 位作者 FENG Bo YU Jie XU Ceng-lin DAI Hai-bin CHEN Zhong HU Wei-wei 《中国药理学与毒理学杂志》 CAS CSCD 北大核心 2018年第9期723-724,共2页
OBJECTIVE Microglia-mediated dis-placement of synapses has been reported in the setting of experimental neuroinflammation,but its role in neurological disorders is poorly understood.Complex febrile seizures(FS) are th... OBJECTIVE Microglia-mediated dis-placement of synapses has been reported in the setting of experimental neuroinflammation,but its role in neurological disorders is poorly understood.Complex febrile seizures(FS) are the most common infantile seizures,yet its pathological progress is largely unknown.METHODS Mice pups(postnatal 8-10 d) were posted to 43℃ hyperthermia condition to develop FS,and then the latency and threshold of seizures were determined.The displacement of synapses was observed through immunofluorescence staining.We researched whether microglial displacement of GABAergic synapses will influence complex FS-induced increase in GABAergic neurotransmission and neuronal excitability with patch-clamp electrophysiology.Moreover,we used the CD11 bD TR mice to selective ablation of microglia or pharmacological inhibition of microglia to observe their effects on susceptibility to FS and synaptic stripping.RESULTS GABAergic presynaptic terminals surrounding neuronal soma and GABAergic transmissions were increased in complex FS.Meanwhile,the activated microglia ensheathe glutamatergic neuronal soma to displace,but do not phagocytize,GABAergic presynaptic terminals.Patch-clamp electrophysiology established that the microglial displacement of GABAergic synapses reduced complex FS-induced increase in GABAergic neurotransmission and neuronal excitability,while GABA exerts excitatory action in this immature stage.Moreover,pharmacological inhibition of microglial displacement of GABAergic synapses or selective ablation of microglia in CD11 bDTR mice promoted the generation of complex FS.CONCLUSION Displacement of GABAergic synapses by microglia is a protective event in the pathological progress of complex FS. 展开更多
关键词 microglia synaptic displacement FEBRILE SEIZURE GABAERGIC NEUROTRANSMISSION
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3-D rheologic model of earthquake preparation (I)—Displacement field 被引量:2
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作者 宋治平 尹祥础 梅世蓉 《Acta Seismologica Sinica(English Edition)》 CSCD 2003年第6期588-597,共10页
Based on the three-dimensional ela stic inclusion model proposed by Dobrovolskii, we developed a three-dimensional rheologic inclusion model and theory to study the earthquake preparation process. By using corresponde... Based on the three-dimensional ela stic inclusion model proposed by Dobrovolskii, we developed a three-dimensional rheologic inclusion model and theory to study the earthquake preparation process. By using correspondence principle in the theory of rheologic mechanics, we derived the analytic expression of the viscoelas-tic displacement at an arbitrary point (x, y, z) in three directions of x, y and z-axes (i. e., U(r, t), V*(r, t) and W(r, t)) produced by a three-dimension inclusion in the semi-infinite rheologic medium defined by the standard linear rheologic model. 展开更多
关键词 elastic inclusion theory rheologic inclusion theory displacement field viscoelastic analytical expression correspondence principle
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APPROXIMATION OF THE CONCENTRATION BY A VISCOSITY SPLITTING METHOD FOR TWO-PHASE MISCIBLE DISPLACEMENT PROBLEM 被引量:1
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作者 梁栋 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1995年第1期75-84,共10页
The miscible displacement of one incompressible fluid by another in a porous medium is considered in this paper. The concentration is split in a first-order hyberbolic equation and a homogeneous parabolic equation wit... The miscible displacement of one incompressible fluid by another in a porous medium is considered in this paper. The concentration is split in a first-order hyberbolic equation and a homogeneous parabolic equation within each lime step. The pressure and Us velocity field is computed by a mixed finite element method. Optimal order estimates are derived for the no diffusion case and the diffusion case. 展开更多
关键词 MISCIBLE displacement PROBLEM VISCOSITY SPLITTING method.
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Separation of closely spaced modes by combining complex envelope displacement analysis with method of generating intrinsic mode functions through filtering algorithm based on wavelet packet decomposition 被引量:3
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作者 Y.S.KIM 陈立群 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2013年第7期801-810,共10页
One of the important issues in the system identification and the spectrum analysis is the frequency resolution, i.e., the capability of distinguishing between two or more closely spaced frequency components. In the mo... One of the important issues in the system identification and the spectrum analysis is the frequency resolution, i.e., the capability of distinguishing between two or more closely spaced frequency components. In the modal identification by the empirical mode decomposition (EMD) method, because of the separating capability of the method, it is still a challenge to consistently and reliably identify the parameters of structures of which modes are not well separated. A new method is introduced to generate the intrin- sic mode functions (IMFs) through the filtering algorithm based on the wavelet packet decomposition (GIFWPD). In this paper, it is demonstrated that the CIFWPD method alone has a good capability of separating close modes, even under the severe condition beyond the critical frequency ratio limit which makes it impossible to separate two closely spaced harmonics by the EMD method. However, the GIFWPD-only based method is impelled to use a very fine sampling frequency with consequent prohibitive computational costs. Therefore, in order to decrease the computational load by reducing the amount of samples and improve the effectiveness of separation by increasing the frequency ratio, the present paper uses a combination of the complex envelope displacement analysis (CEDA) and the GIFWPD method. For the validation, two examples from the previous works are taken to show the results obtained by the GIFWPD-only based method and by combining the CEDA with the GIFWPD method. 展开更多
关键词 empirical mode decomposition (EMD) wavelet packet decomposition com- plex envelope displacement analysis (CEDA) closely spaced modes modal identification
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3D Microdisplacement Monitoring of Large Aircraft Assembly with Automated In Situ Calibration 被引量:1
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作者 Zhenyuan Jia Bing Liang +2 位作者 Wei Liu Kun Liu Jianwei Ma 《Engineering》 SCIE EI CAS 2022年第12期105-116,共12页
Three-dimensional(3D)microdisplacement monitoring plays a crucial role in the assembly of large aircraft.This paper presents a broadly applicable high-precision online 3D microdisplacement monitoring method and system... Three-dimensional(3D)microdisplacement monitoring plays a crucial role in the assembly of large aircraft.This paper presents a broadly applicable high-precision online 3D microdisplacement monitoring method and system based on proximity sensors as well as a corresponding in situ calibration method,which can be applied under various extreme working conditions encountered in the aircraft assembly process,such as compact and obstructed spaces.A 3D monitoring model is first established to achieve 3D microdisplacement monitoring based only on the one-dimensional distances measured by proximity sensors,which concerns the extrinsic sensor parameters,such as the probe base point(PBP)and the unit displacement vector(UDV).Then,a calibration method is employed to obtain these extrinsic parameters with high precision by combining spatial transformation principles and weighted optimization.Finally,calibration and monitoring experiments performed for a tailplane assembly process are reported.The calibration precision for the PBP is better than±10 lm in the X and Y directions and±2 lm in the Z direction,and the calibration precision for the UDV is better than 0.07°.Moreover,the accuracy of the 3D microdisplacement monitoring system can reach±15 lm.In general,this paper provides new insights into the modeling and calibration of 3D microdisplacement monitoring based on proximity sensors and a precise,efficient,and low-cost technical means for performing related measurements in compact spaces during the aircraft assembly process. 展开更多
关键词 Aircraft manufacture ASSEMBLY CALIBratioN Condition monitoring displacement measurement
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Robust vision-based displacement measurement and acceleration estimation using RANSAC and Kalman filter 被引量:1
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作者 Jongbin Won Jong-Woong Park +2 位作者 Min-Hyuk Song Youn-Sik Kim Dosoo Moon 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第2期347-358,共12页
Computer vision(CV)-based techniques have been widely used in the field of structural health monitoring(SHM)owing to ease of installation and cost-effectiveness for displacement measurement.This paper introduces compu... Computer vision(CV)-based techniques have been widely used in the field of structural health monitoring(SHM)owing to ease of installation and cost-effectiveness for displacement measurement.This paper introduces computer vision based method for robust displacement measurement under occlusion by incorporating random sample consensus(RANSAC).The proposed method uses the Kanade-Lucas-Tomasi(KLT)tracker to extract feature points for tracking,and these feature points are filtered through RANSAC to remove points that are noisy or occluded.With the filtered feature points,the proposed method incorporates Kalman filter to estimate acceleration from velocity and displacement extracted by the KLT.For validation,numerical simulation and experimental validation are conducted.In the simulation,performance of the proposed RANSAC filtering was validated to extract correct displacement out of group of displacements that includes dummy displacement with noise or bias.In the experiment,both RANSAC filtering and acceleration measurement were validated by partially occluding the target for tracking attached on the structure.The results demonstrated that the proposed method successfully measures displacement and estimates acceleration as compared to a reference displacement sensor and accelerometer,even under occluded conditions. 展开更多
关键词 computer vision structural displacement structural acceleration RANSAC Kalman filter
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Improved calibration method for displacement transformation coefficient in optical and visual measurements
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作者 Haopeng Li Zurong Qiu 《Nanotechnology and Precision Engineering》 CAS CSCD 2023年第1期12-25,共14页
Optical and visual measurement technology is used widely in fields that involve geometric measurements,and among such technology are laser and vision-based displacement measuring modules(LVDMMs).The displacement trans... Optical and visual measurement technology is used widely in fields that involve geometric measurements,and among such technology are laser and vision-based displacement measuring modules(LVDMMs).The displacement transformation coefficient(DTC)of an LVDMM changes with the coordinates in the camera image coordinate system during the displacement measuring process,and these changes affect the displacement measurement accuracy of LVDMMs in the full field of view(FFOV).To give LVDMMs higher accuracy in the FFOV and make them adaptable to widely varying measurement demands,a new calibration method is proposed to improve the displacement measurement accuracy of LVDMMs in the FFOV.First,an image coordinate system,a pixel measurement coordinate system,and a displacement measurement coordinate system are established on the laser receiving screen of the LVDMM.In addition,marker spots in the FFOV are selected,and the DTCs at the marker spots are obtained from calibration experiments.Also,a fitting method based on locally weighted scatterplot smoothing(LOWESS)is selected,and with this fitting method the distribution functions of the DTCs in the FFOV are obtained based on the DTCs at the marker spots.Finally,the calibrated distribution functions of the DTCs are applied to the LVDMM,and experiments conducted to verify the displacement measurement accuracies are reported.The results show that the FFOV measurement accuracies for horizontal and vertical displacements are better than±15μm and±19μm,respectively,and that for oblique displacement is better than±24μm.Compared with the traditional calibration method,the displacement measurement error in the FFOV is now 90%smaller.This research on an improved calibration method has certain significance for improving the measurement accuracy of LVDMMs in the FFOV,and it provides a new method and idea for other vision-based fields in which camera parameters must be calibrated. 展开更多
关键词 displacement transformation coefficient(DTC) Laser and vision-based displacement measuring module(LVDMM) displacement measurement Locally weighted scatterplot smoothing(LOWESS) Calibration method
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Red cell distribution width-to-albumin ratio is a simple promising prognostic marker in acute cholangitis requiring biliary drainage 被引量:2
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作者 Fatih Acehan Hüseyin Camli +4 位作者 Cagdas Kalkan Mesut Tez Burak Furkan Demir Emin Altiparmak Ihsan Ates 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2024年第5期487-494,共8页
Background: It is crucial to assess the severity of acute cholangitis(AC). There are currently several prognostic markers. However, the accuracies of these markers are not satisfied. The present study aimed to investi... Background: It is crucial to assess the severity of acute cholangitis(AC). There are currently several prognostic markers. However, the accuracies of these markers are not satisfied. The present study aimed to investigate the predictive value of the red cell distribution width(RDW)-to-albumin ratio(RAR) for the prognosis of AC. Methods: We retrospectively evaluated consecutive patients diagnosed with AC between May 2019 and March 2022. RAR was calculated, and its predictive ability for in-hospital mortality, intensive care unit(ICU) admission, bacteremia, and the length of hospitalization were analyzed. Results: Out of 438 patients, 34(7.8%) died. Multivariate analysis showed that malignant etiology [odds ratio(OR) = 4.816, 95% confidence interval(CI): 1.936-11.980], creatinine(OR = 1.649, 95% CI: 1.095-2.484), and RAR(OR = 2.064, 95% CI: 1.494-2.851) were independent risk factors for mortality. When adjusted for relevant covariates, including age, sex, malignant etiology, Tokyo severity grading(TSG), Charlson comorbidity index, and creatinine, RAR significantly predicted mortality(adjusted OR = 1.833, 95% CI: 1.280-2.624). When the cut-off of RAR was set to 3.8, its sensitivity and specificity for mortality were 94.1% and 56.7%, respectively. Patients with an RAR of > 3.8 had a 20.9-fold(OR = 20.9, 95% CI: 4.9-88.6) greater risk of mortality than the remaining patients. The area under the curve value of RAR for mortality was 0.835(95% CI: 0.770-0.901), which was significantly higher than that of TSG and the other prognostic markers, such as C-reactive protein-to-albumin ratio, and procalcitonin-to-albumin ratio. Lastly, RAR was not inferior to TSG in predicting ICU admission, bacteremia, and the length of hospitalization. Conclusions: RAR successfully predicted the in-hospital mortality, ICU admission, bacteremia, and the length of hospitalization of patients with AC, especially in-hospital mortality. RAR is a promising marker that is more convenient than TSG and other prognostic markers for predicting the prognosis of patients with AC. 展开更多
关键词 Acute cholangitis ALBUMIN Biliary drainage MORTALITY Red blood cell distribution width-to-albumin ratio
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Consideration on the Flow Velocity in the Experimental Analysis of the Flame Displacement Speed Using DNS Data of Turbulent Premixed Flames with Different Lewis Numbers
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作者 Kazuya Tsuboi Shingo Morishita Eiji Tomita 《Open Journal of Fluid Dynamics》 2014年第3期278-287,共10页
The flame displacement speed is one of the major characteristics in turbulent premixed flames. The flame displacement speed is experimentally obtained from the displacement normal to the flame surface, while it is num... The flame displacement speed is one of the major characteristics in turbulent premixed flames. The flame displacement speed is experimentally obtained from the displacement normal to the flame surface, while it is numerically evaluated by the transport equation of the flame surface. The flame displacement speeds obtained both experimentally and numerically cannot be compared directly because their definitions are different. In this study, two kinds of experimental flame displacement speeds—involving the mean inflow velocity and the local flow velocity—were simulated using the DNS data with the different Lewis numbers, and were compared with the numerical flame displacement speed. The simulated experimental flame displacement speed involving the mean inflow velocity had no correlation with the numerical flame displacement speed, while the simulated displacement speed involving the local flow velocity had a clear correlation with the numerical displacement speed in the cases of higher Lewis number than unity. The correlation coefficient of the simulated displacement speed involving the local flow velocity with the numerical displacement speed had a maximum value on the isosurface of the reaction progress variable with the maximum temperature gradient where the dilation effect of the flame is strongest. 展开更多
关键词 FLAME displacement SPEED Simulating Experimental Measurement and Analysis LEWIS Number DILATION Effect Turbulent PREMIXED FLAME Direct Numerical Simulation
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