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Co-seismic surface displacement of the June 21, 2022 M_W6 Khōst,Afghanistan earthquake from InSAR observations
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作者 Prohelika Dalal Batakrushna Senapati Bhaskar Kundu 《Geodesy and Geodynamics》 EI CSCD 2024年第3期201-208,共8页
A robust estimation of the earthquake location, seismic moment, and fault geometry is essential for objective seismic hazard assessment. Seismic events in a remote location, specifically in the absence of seismic and ... A robust estimation of the earthquake location, seismic moment, and fault geometry is essential for objective seismic hazard assessment. Seismic events in a remote location, specifically in the absence of seismic and GNSS networks, can be investigated effectively using the In SAR-based technique. This study adopts the Differential Interferometric SAR(DIn SAR) technique to quantify the co-seismic surface displacement caused by the June 21, 2022, Khōst M_(W)6 earthquake that occurred along the western plate boundary between the Indian and Eurasian plate. The interferograms show that the maximum surface deformation occurred on the northwest and southwest of the fault line. From coherence, the Line of Sight(LOS) displacement, and the co-seismic surface displacement analysis, it has been observed that surface deformation was most pronounced in the southwest region of the fault line, and the surface has moved to the opposite direction along the fault line, which indicates a sinistral slightly oblique strike-slip movement. This In SAR-based observation appears consistent with the seismic waveforms derived from co-seismic surface displacements. Further, it has been argued that the slip deficit accumulated during the period of the last about 48 years along the frontal region of the northward extension of the Suleiman range and associated fault zone is qualitatively estimated at about 1.5 m, which is consistent with the seismic waveforms derived finite slip model. 展开更多
关键词 Seismic hazard Khōst earthquake DINSAR Slip deficit LOS displacement Finite slip model
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Development of a 2D spatial displacement estimation method for turbulence velocimetry of the gas puff imaging system on EAST
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作者 李乐天 刘少承 +2 位作者 颜宁 刘晓菊 高翔 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第3期17-24,共8页
A gas puff imaging(GPI)diagnostic has been developed and operated on EAST since 2012,and the time-delay estimation(TDE)method is used to derive the propagation velocity of fluctuations from the two-dimensional GPI dat... A gas puff imaging(GPI)diagnostic has been developed and operated on EAST since 2012,and the time-delay estimation(TDE)method is used to derive the propagation velocity of fluctuations from the two-dimensional GPI data.However,with the TDE method it is difficult to analyze the data with fast transient events,such as edge-localized mode(ELM).Consequently,a method called the spatial displacement estimation(SDE)algorithm is developed to estimate the turbulence velocity with high temporal resolution.Based on the SDE algorithm,we make some improvements,including an adaptive median filter and super-resolution technology.After the development of the algorithm,a straight-line movement and a curved-line movement are used to test the accuracy of the algorithm,and the calculated speed agrees well with preset speed.This SDE algorithm is applied to the EAST GPI data analysis,and the derived propagation velocity of turbulence is consistent with that from the TDE method,but with much higher temporal resolution. 展开更多
关键词 gas puff imaging spatial displacement estimation SDE edge turbulence velocity TDE EAST tokamak
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Direct scaling of residual displacements for bilinear and pinching oscillators
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作者 Mohammad Saifullah Vinay K.Gupta 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期129-149,共21页
The estimation of residual displacements in a structure due to an anticipated earthquake event has increasingly become an important component of performance-based earthquake engineering because controlling these displ... The estimation of residual displacements in a structure due to an anticipated earthquake event has increasingly become an important component of performance-based earthquake engineering because controlling these displacements plays an important role in ensuring cost-feasible or cost-effective repairs in a damaged structure after the event.An attempt is made in this study to obtain statistical estimates of constant-ductility residual displacement spectra for bilinear and pinching oscillators with 5%initial damping,directly in terms of easily available seismological,site,and model parameters.None of the available models for the bilinear and pinching oscillators are useful when design spectra for a seismic hazard at a site are not available.The statistical estimates of a residual displacement spectrum are proposed in terms of earthquake magnitude,epicentral distance,site geology parameter,and three model parameters for a given set of ductility demand and a hysteretic energy capacity coefficient in the case of bilinear and pinching models,as well as for a given set of pinching parameters for displacement and strength at the breakpoint in the case of pinching model alone.The proposed scaling model is applicable to horizontal ground motions in the western U.S.for earthquake magnitudes less than 7 or epicentral distances greater than 20 km. 展开更多
关键词 residual displacement spectrum bilinear hysteresis model pinching hysteresis model nonlinear analysis scaling model
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Short-term displacement prediction for newly established monitoring slopes based on transfer learning
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作者 Yuan Tian Yang-landuo Deng +3 位作者 Ming-zhi Zhang Xiao Pang Rui-ping Ma Jian-xue Zhang 《China Geology》 CAS CSCD 2024年第2期351-364,共14页
This study makes a significant progress in addressing the challenges of short-term slope displacement prediction in the Universal Landslide Monitoring Program,an unprecedented disaster mitigation program in China,wher... This study makes a significant progress in addressing the challenges of short-term slope displacement prediction in the Universal Landslide Monitoring Program,an unprecedented disaster mitigation program in China,where lots of newly established monitoring slopes lack sufficient historical deformation data,making it difficult to extract deformation patterns and provide effective predictions which plays a crucial role in the early warning and forecasting of landslide hazards.A slope displacement prediction method based on transfer learning is therefore proposed.Initially,the method transfers the deformation patterns learned from slopes with relatively rich deformation data by a pre-trained model based on a multi-slope integrated dataset to newly established monitoring slopes with limited or even no useful data,thus enabling rapid and efficient predictions for these slopes.Subsequently,as time goes on and monitoring data accumulates,fine-tuning of the pre-trained model for individual slopes can further improve prediction accuracy,enabling continuous optimization of prediction results.A case study indicates that,after being trained on a multi-slope integrated dataset,the TCN-Transformer model can efficiently serve as a pretrained model for displacement prediction at newly established monitoring slopes.The three-day average RMSE is significantly reduced by 34.6%compared to models trained only on individual slope data,and it also successfully predicts the majority of deformation peaks.The fine-tuned model based on accumulated data on the target newly established monitoring slope further reduced the three-day RMSE by 37.2%,demonstrating a considerable predictive accuracy.In conclusion,taking advantage of transfer learning,the proposed slope displacement prediction method effectively utilizes the available data,which enables the rapid deployment and continual refinement of displacement predictions on newly established monitoring slopes. 展开更多
关键词 LANDSLIDE Slope displacement prediction Transfer learning Integrated dataset Transformer Pre-trained model Universal Landslide Monitoring Program(ULMP) Geological hazards survey engineering
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A technique for enhancing tight oil recovery by multi-field reconstruction and combined displacement and imbibition
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作者 LEI Zhengdong WANG Zhengmao +6 位作者 MU Lijun PENG Huanhuan LI Xin BAI Xiaohu TAO Zhen LI Hongchang PENG Yingfeng 《Petroleum Exploration and Development》 SCIE 2024年第1期152-163,共12页
A seepage-geomechanical coupled embedded fracture flow model has been established for multi-field coupled simulation in tight oil reservoirs,revealing the patterns of change in pressure field,seepage field,and stress ... A seepage-geomechanical coupled embedded fracture flow model has been established for multi-field coupled simulation in tight oil reservoirs,revealing the patterns of change in pressure field,seepage field,and stress field after long-term water injection in tight oil reservoirs.Based on this,a technique for enhanced oil recovery(EOR)combining multi-field reconstruction and combination of displacement and imbibition in tight oil reservoirs has been proposed.The study shows that after long-term water flooding for tight oil development,the pressure diffusion range is limited,making it difficult to establish an effective displacement system.The variation in geostress exhibits diversity,with the change in horizontal minimum principal stress being greater than that in horizontal maximum principal stress,and the variation around the injection wells being more significant than that around the production wells.The deflection of geostress direction around injection wells is also large.The technology for EOR through multi-field reconstruction and combination of displacement and imbibition employs water injection wells converted to production and large-scale fracturing techniques to restructure the artificial fracture network system.Through a full lifecycle energy replenishment method of pre-fracturing energy supplementation,energy increase during fracturing,well soaking for energy storage,and combination of displacement and imbibition,it effectively addresses the issue of easy channeling of the injection medium and difficult energy replenishment after large-scale fracturing.By intensifying the imbibition effect through the coordination of multiple wells,it reconstructs the combined system of displacement and imbibition under a complex fracture network,transitioning from avoiding fractures to utilizing them,thereby improving microscopic sweep and oil displacement efficiencies.Field application in Block Yuan 284 of the Huaqing Oilfield in the Ordos Basin has demonstrated that this technology increases the recovery factor by 12 percentage points,enabling large scale and efficient development of tight oil. 展开更多
关键词 tight oil complex fracture network energy increase by fracturing multi-field reconstruction displacement and imbibition combination EOR
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Estimation of Displacement and Extension due to Reverse Drag of Normal Faults: Forward Method
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作者 Shunshan Xu Angel Francisco Nieto-Samaniego +1 位作者 Huilong Xu Susana Alicia Alaniz-Álvarez 《International Journal of Geosciences》 CAS 2024年第1期25-39,共15页
In the case of reverse drag of normal faulting, the displacement and horizontal extension are determined based on the established equations for the three mechanisms: rigid body, vertical shear and inclined shear. Ther... In the case of reverse drag of normal faulting, the displacement and horizontal extension are determined based on the established equations for the three mechanisms: rigid body, vertical shear and inclined shear. There are three sub-cases of basal detachment for the rigid body model: horizontal detachment, antithetic detachment and synthetic detachment. For the rigid body model, the established equations indicate that the total displacement on the synthetic base (D<sub>t2</sub>) is the largest, that on the horizontal base (D<sub>t1</sub>) is moderate, and that on the antithetic base (D<sub>t3</sub>) is the smallest. On the other hand, the value of (D<sub>t1</sub>) is larger than the displacement for the vertical shear (D<sub>t4</sub>). The value of (D<sub>t1</sub>) is larger than or less than the displacement for the inclined shear (D<sub>t5</sub>) depending on the original fault dip δ<sub>0</sub>, bedding angle θ, and the angle of shear direction β. For all original parameters, the value of D<sub>t5</sub> is less than the value of D<sub>t4</sub>. Also, by comparing three rotation mechanisms, we find that the inclined shear produces largest extension, the rigid body model with horizontal detachment produces the smallest extension, and the vertical shear model produces moderate extension. 展开更多
关键词 Fault Rotation Fault Drag Fault displacement EXTENSION Forward Model
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Effect of Articular Cavity Injection Combined with Bite Splint Treatment on Anterior Disc Displacement Without Reduction
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作者 Mengran Zhu Linghong Xu 《Journal of Clinical and Nursing Research》 2024年第1期133-139,共7页
Objective:To observe the clinical effect of articular cavity injection combined with bite splint therapy for the treatment of anterior disc displacement without reduction(ADDWoR).Methods:The research subjects for this... Objective:To observe the clinical effect of articular cavity injection combined with bite splint therapy for the treatment of anterior disc displacement without reduction(ADDWoR).Methods:The research subjects for this study were 30 patients with ADDWoR treated in the temporomandibular joint specialist outpatient clinic from November 2018 to November 2019,with a disease duration of 1 to 6 months.The treatment group was treated with an articular cavity injection of sodium hyaluronate+bite splint.The control group was treated with a simple articular cavity injection of sodium hyaluronate.The two groups were followed up once every 2 weeks to evaluate the treatment effect and observe the clinical efficacy of the two groups.Statistical analysis was carried out using SPSS 24.0.t-test and general linear regression analysis were carried out to compare the data of both groups,andχ^(2)-test and binary logistic regression analysis were performed for pain index comparison.Results:There was no significant difference in terms of the efficacy of the treatment received by both groups.The mouth opening and joint pain of patients in both groups were significantly improved after treatment(P<0.001).Conclusion:Articular cavity injection of sodium hyaluronate and occlusal splint therapy are both effective and safe methods for treating ADDWoR. 展开更多
关键词 Temporomandibular disorders Anterior disc displacement without reduction Sodium hyaluronate SPLINT
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Phase-Based Optical Flow Method with Optimized Parameter Settings for Enhancing Displacement Measurement Adaptability
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作者 Zhaoxin Peng Menglian Liu +2 位作者 Zhiliang Wang Wei Liu Xian Wang 《Open Journal of Applied Sciences》 2024年第5期1165-1184,共20页
To enhance the applicability and measurement accuracy of phase-based optical flow method using complex steerable pyramids in structural displacement measurement engineering applications, an improved method of optimizi... To enhance the applicability and measurement accuracy of phase-based optical flow method using complex steerable pyramids in structural displacement measurement engineering applications, an improved method of optimizing parameter settings is proposed. The optimized parameters include the best measurement points of the Region of Interest (ROI) and the levels of pyramid filters. Additionally, to address the issue of updating reference frames in practical applications due to the difficulty in estimating the maximum effective measurement value, a mechanism for dynamically updating reference frames is introduced. Experimental results demonstrate that compared to representative image gradient-based displacement measurement methods, the proposed method exhibits higher measurement accuracy in engineering applications. This provides reliable data support for structural damage identification research based on vibration signals and is expected to broaden the engineering application prospects for structural health monitoring. 展开更多
关键词 displacement Measurement Phase-Based Optical Flow Optimized Parameter Setting
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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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Inelastic displacement ratio of low-to mid-rise BRBFs designed under variable levels of seismicity
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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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Landslide displacement prediction based on the ICEEMDAN,ApEn and the CNN-LSTM models 被引量:2
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作者 LI Li-min WANG Chao-yang +2 位作者 WEN Zong-zhou GAO Jian XIA Meng-fan 《Journal of Mountain Science》 SCIE CSCD 2023年第5期1220-1231,共12页
Landslide deformation is affected by its geological conditions and many environmental factors.So it has the characteristics of dynamic,nonlinear and unstable,which makes the prediction of landslide displacement diffic... Landslide deformation is affected by its geological conditions and many environmental factors.So it has the characteristics of dynamic,nonlinear and unstable,which makes the prediction of landslide displacement difficult.In view of the above problems,this paper proposes a dynamic prediction model of landslide displacement based on the improvement of complete ensemble empirical mode decomposition with adaptive noise(ICEEMDAN),approximate entropy(ApEn)and convolution long short-term memory(CNN-LSTM)neural network.Firstly,ICEEMDAN and Ap En are used to decompose the cumulative displacements into trend,periodic and random displacements.Then,the least square quintic polynomial function is used to fit the displacement of trend term,and the CNN-LSTM is used to predict the displacement of periodic term and random term.Finally,the displacement prediction results of trend term,periodic term and random term are superimposed to obtain the cumulative displacement prediction value.The proposed model has been verified in Bazimen landslide in the Three Gorges Reservoir area of China.The experimental results show that the model proposed in this paper can more effectively predict the displacement changes of landslides.As compared with long short-term memory(LSTM)neural network,gated recurrent unit(GRU)network model and back propagation(BP)neural network,CNN-LSTM neural network had higher prediction accuracy in predicting the periodic displacement,with the mean absolute percentage error(MAPE)reduced by 3.621%,6.893% and 15.886% respectively,and the root mean square error(RMSE)reduced by 3.834 mm,3.945 mm and 7.422mm respectively.Conclusively,this model not only has high prediction accuracy but also is more stable,which can provide a new insight for practical landslide prevention and control engineering. 展开更多
关键词 displacement prediction ICEENDAN Approximate entropy Long short-term memory Bazimen landslide
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Anomaly detection on displacement rates and deformation pattern features using tree-based algorithm in Japan and Indonesia 被引量:1
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作者 Adi Wibowo Satriawan Rasyid Purnama +3 位作者 Cecep Pratama Leni Sophia Heliani David P.Sahara Sidik Tri Wibowo 《Geodesy and Geodynamics》 CSCD 2023年第2期150-162,共13页
Research on strain anomalies and large earthquakes based on temporal and spatial crustal activities has been rapidly growing due to data availability, especially in Japan and Indonesia. However, many research works us... Research on strain anomalies and large earthquakes based on temporal and spatial crustal activities has been rapidly growing due to data availability, especially in Japan and Indonesia. However, many research works used local-scale case studies that focused on a specific earthquake characteristic using knowledgedriven techniques, such as crustal deformation analysis. In this study, a data-driven-based analysis is used to detect anomalies using displacement rates and deformation pattern features extracted from daily global navigation satellite system(GNSS) data using a machine learning algorithm. The GNSS data with188 and 1181 continuously operating reference stations from Indonesia and Japan, respectively, are used to identify the anomaly of recent major earthquakes in the last two decades. Feature displacement rates and deformation patterns are processed in several window times with 2560 experiment scenarios to produce the best detection using tree-based algorithms. Tree-based algorithms with a single estimator(decision tree), ensemble bagging(bagging, random forest and Extra Trees), and ensemble boosting(AdaBoost, gradient boosting, LGBM, and XGB) are applied in the study. The experiment test using realtime scenario GNSSdailydatareveals high F1-scores and accuracy for anomaly detection using slope windowing 365 and 730 days of 91-day displacement rates and then 7-day deformation pattern features in tree-based algorithms. The results show the potential for medium-term anomaly detection using GNSS data without the need for multiple vulnerability assessments. 展开更多
关键词 ANOMALY GNSS displacement rates Deformation pattern Tree-based algorithm
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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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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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Analysis of displacement damage effects on the charge-coupled device induced by neutrons at Back-n in the China Spallation Neutron Source 被引量:1
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作者 薛院院 王祖军 +9 位作者 陈伟 郭晓强 姚志斌 何宝平 聂栩 赖善坤 黄港 盛江坤 马武英 缑石龙 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期435-442,共8页
Displacement damage effects on the charge-coupled device(CCD)induced by neutrons at the back-streaming white neutron source(Back-n)in the China Spallation Neutron Source(CSNS)are analyzed according to an online irradi... Displacement damage effects on the charge-coupled device(CCD)induced by neutrons at the back-streaming white neutron source(Back-n)in the China Spallation Neutron Source(CSNS)are analyzed according to an online irradiation experiment.The hot pixels,random telegraph signal(RTS),mean dark signal,dark current and dark signal non-uniformity(DSNU)induced by Back-n are presented.The dark current is calculated according to the mean dark signal at various integration times.The single-particle displacement damage and transient response are also observed based on the online measurement data.The trends of hot pixels,mean dark signal,DSNU and RTS degradation are related to the integration time and irradiation fluence.The mean dark signal,dark current and DSNU2 are nearly linear with neutron irradiation fluence when nearly all the pixels do not reach saturation.In addition,the mechanisms of the displacement damage effects on the CCD are demonstrated by combining the experimental results and technology computer-aided design(TCAD)simulation.Radiation-induced traps in the space charge region of the CCD will act as generation/recombination centers of electron-hole pairs,leading to an increase in the dark signal. 展开更多
关键词 displacement damage effects charge-coupled device(CCD) China Spallation Neutron Source(CSNS) MECHANISMS technology computer-aided design(TCAD)
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Molecular insight into the oil displacement mechanism of CO_(2) flooding in the nanopores of shale oil reservoir
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作者 Xiao-Hu Dong Wen-Jing Xu +2 位作者 Hui-Qing Liu Zhang-Xing Chen Ning Lu 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3516-3529,共14页
With the increasing demand for petroleum,shale oil with considerable reserves has become an important part of global oil resources.The shale oil reservoir has a large number of nanopores and a complicated mineral comp... With the increasing demand for petroleum,shale oil with considerable reserves has become an important part of global oil resources.The shale oil reservoir has a large number of nanopores and a complicated mineral composition,and the effect of nanopore confinement and pore type usually makes the effective development of shale oil challenging.For a shale oil reservoir,CO_(2) flooding can effectively reduce the oil viscosity and improve the reservoir properties,which can thus improve the recovery performance.In this study,the method of non-equilibrium molecular dynamics(NEMD)simulation is used to simulate the CO_(2) flooding process in the nanoscale pores of shale oil reservoir.The performance difference between the organic kerogen slit nanopore and four types of inorganic nanopores is discussed.Thus,the effects of nanopore type and displacement velocity on the nanoscale displacement behavior of CO_(2) are analyzed.Results indicate that the CO_(2) flooding process of different inorganic pores is different.In comparison,the displacement efficiency of light oil components is higher,and the transport distance is longer.The intermolecular interaction can significantly affect the CO_(2) displacement behavior in nanopores.The CO_(2) displacement efficiency is shown as montmorillonite,feldspar>quartz>calcite>kerogen.On the other hand,it is found that a lower displacement velocity can benefit the miscibility process between alkane and CO_(2),which is conducive to the overall displacement process of CO_(2).The displacement efficiency can significantly decrease with the increase in displacement velocity.But once the displacement velocity is very high,the strong driving force can promote the alkane to move forward,and the displacement efficiency will recover slightly.This study further reveals the microscopic oil displacement mechanism of CO_(2) in shale nanopores,which is of great significance for the effective development of shale oil reservoirs by using the method of CO_(2) injection. 展开更多
关键词 displacement behavior NANOPORES NEMD simulation Shale oil CO_(2) KEROGEN
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Visualization of real-time displacement time history superimposed with dynamic experiments using wireless smart sensors and augmented reality
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作者 Marlon Aguero Derek Doyle +1 位作者 David Mascarenas Fernando Moreu 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第3期573-588,共16页
Wireless smart sensors(WSS)process field data and inform inspectors about the infrastructure health and safety.In bridge engineering,inspectors need reliable data about changes in displacements under loads to make cor... Wireless smart sensors(WSS)process field data and inform inspectors about the infrastructure health and safety.In bridge engineering,inspectors need reliable data about changes in displacements under loads to make correct decisions about repairs and replacements.Access to displacement information in the field and in real-time remains a challenge as inspectors do not see the data in real time.Displacement data from WSS in the field undergoes additional processing and is seen at a different location.If inspectors were able to see structural displacements in real-time at the locations of interest,they could conduct additional observations,creating a new,information-based,decision-making reality in the field.This paper develops a new,human-centered interface that provides inspectors with real-time access to actionable structural data during inspection and monitoring enhanced by augmented reality(AR).It summarizes and evaluates the development and validation of the new human-infrastructure interface in laboratory experiments.The experiments demonstrate that the interface that processes all calculations in the AR device accurately estimates dynamic displacements in comparison with the laser.Using this new AR interface tool,inspectors can observe and compare displacement data,share it across space and time,visualize displacements in time history,and understand structural deflection more accurately through a displacement time history visualization. 展开更多
关键词 wireless smart sensor monitoring augmented reality displacement ACCELERATION human-infrastructure interface
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Unraveling the influence of surface roughness on oil displacement by Janus nanoparticles
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作者 Yuan-Hao Chang Sen-Bo Xiao +2 位作者 Rui Ma Zhi-Liang Zhang Jian-Ying He 《Petroleum Science》 SCIE EI CAS CSCD 2023年第4期2512-2520,共9页
Janus nanoparticles(JNPs)possess great potential in recovering the residual oil from reservoirs,however,the fundamental interaction mechanisms among nanoparticles,the oil,and reservoir wall characteristics remain to b... Janus nanoparticles(JNPs)possess great potential in recovering the residual oil from reservoirs,however,the fundamental interaction mechanisms among nanoparticles,the oil,and reservoir wall characteristics remain to be elucidated.In this work,models of oil trapping grooves with different geometric features are subjected to molecular dynamics simulations for investigating the influences of roughness parameters on oil displacement dynamics by JNPs.Four key surface geometry parameters and different degrees of surface hydrophobicity are considered.Our results indicate that JNPs hold an outstanding performance in displacing residual oil on weakly to moderately hydrophobic surfaces.Overall,smaller entry and exit angles,the larger aspect ratio of the oil trapping grooves,and a bigger tip length of the rough ridges lead to superior oil recovery.Among the key geometric parameters,the aspect ratio of the oil trapping grooves plays the dominant role.These insights about the interaction of surface properties and JNPs and the resulting trapped oil displacement could serve as a theoretical reference for the application of JNPs for targeted reservoir conditions. 展开更多
关键词 Janus nanoparticles Oil displacement Enhanced oil recovery Molecular dynamics simulation Rough surface
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Production characteristics and displacement mechanisms of infilling polymer-surfactant-preformed particle gel flooding in post-polymer flooding reservoirs:A review of practice in Ng3 block of Gudao Oilfield
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作者 Zhi-Bin An Kang Zhou +1 位作者 De-Jun Wu Jian Hou 《Petroleum Science》 SCIE EI CAS CSCD 2023年第4期2354-2371,共18页
The pilot test of infilling polymer-surfactant-preformed particle gel(PPG)flooding has been successfully implemented after polymer flooding in Ng3 block of Gudao Oilfield in China.However,the production characteristic... The pilot test of infilling polymer-surfactant-preformed particle gel(PPG)flooding has been successfully implemented after polymer flooding in Ng3 block of Gudao Oilfield in China.However,the production characteristics and displacement mechanisms are still unclear,which restricts its further popularization and application.Aiming at this problem,this paper firstly analyzes the production performance of the pilot test and proposed four response types according to the change of water cut curves,including W-type,U-type,V-type response,and no response.Furthermore,the underlying reasons of these four types are analyzed from the aspects of seepage resistance and sweep efficiency.The overall sweep efficiency of gradual-rising W-type,gradual-decreasing W-type,and early V-type response increases from 0.81 to 0.93,0.55 to 0.89,and 0.94 to 1,respectively.And the sum of seepage resistance along the connection line between production well and injection well for U-type and delayed V-type response increases from 0.0994 to 0.2425,and 0.0677 to 0.1654,respectively.Then,the remaining oil distribution after polymer flooding is summarized into four types on the basis of production and geological characteristics,namely disconnected remaining oil,streamline unswept remaining oil,rhythm remaining oil,and interlayer-controlled remaining oil.Furthermore,the main displacement mechanisms for each type are clarified based on the dimensionless seepage resistance and water absorption profile.Generally,improving connectivity by well pattern infilling is the most important for producing disconnected remaining oil.The synergistic effect of well pattern infilling and polymer-surfactant-PPG flooding increases the dimensionless seepage resistance of water channeling regions and forces the subsequent injected water to turn to regions with streamline unswept remaining oil.The improvement of the water absorption profile by polymer-surfactant-PPG flooding and separated layer water injection contributes to displacing rhythm remaining oil and interlayer-controlled remaining oil.Finally,the paper analyzes the relationships between the remaining oil distribution after polymer flooding and production characteristics of infilling polymer-surfactant-PPG flooding.The study helps to deepen the understanding of infilling polymer-surfactant-PPG flooding and has reference significance for more commercial implementations in the future. 展开更多
关键词 Infilling polymer-surfactant-PPG flooding Production characteristics displacement mechanisms Dimensionless seepage resistance Water absorption profile
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Optimization of anchorage support parameters for soft rock tunnel based on displacement control theory
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作者 LI Gan MA Wei-bin +2 位作者 YU Chang-yi TAO Zhi-gang WANG Feng-nian 《Journal of Mountain Science》 SCIE CSCD 2023年第7期2076-2092,共17页
In the construction of a soft rock tunnel,it is critical to accurately estimate the pre-stressed anchor support parameters for surrounding rock reinforcement;otherwise,engineering disasters may occur.This paper presen... In the construction of a soft rock tunnel,it is critical to accurately estimate the pre-stressed anchor support parameters for surrounding rock reinforcement;otherwise,engineering disasters may occur.This paper presents a support parameter selection method that aims to allow deformation as a control objective,which was applied to the tunnel located in Muzailing Highway,Min County,Dingxi City,Gansu Province,China.Through theoretical analysis,we have identified five factors that influence pre-stressing anchorages.The selection of mechanical parameters for the rock mass was carried out using an inverse analysis method.Compared with the measured data,the maximum displacement error of the numerical simulation results was only 0.07 m.The length of anchor cable,circumferential spacing of anchor cable,longitudinal spacing,and pre-stress index are adopted as the input parameters for the support vector machine neural network model based on particle swarm optimization(PSO-LSSVM).Besides,the vault subsidence and the maximum deformation of surrounding rock are considered as output values(performance indices).The goodness of fit between the predicted values and the simulated values exceeds 0.9.Finally,all support parameters within the acceptable deformation range are calculated.The optimal support variables are derived by considering the construction cost and duration.The field application results show that it is feasible to construct the sample database utilizing the numerical simulation approach by taking the displacement as the control target and using the neural network to specify the appropriate support parameters. 展开更多
关键词 displacement control theory Anchorage support parameters Numerical simulation PSOLSSVM Tunnel construction
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