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Assessment of International GNSS Service Global Ionosphere Map products over China region based on measurements from the Crustal Movement Observation Network of China 被引量:1
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作者 Jin Hu HaiBing Ruan +2 位作者 FuQing Huang ShengYang Gu XianKang Dou 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期400-407,共8页
The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of G... The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions. 展开更多
关键词 International GNSS Service(IGS)Global Ionosphere Maps(GIM) Crustal movement Observation Network of China(CMONOC) total electron content(TEC) data assessment
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Pedestrian lane formation with following–overtaking model and measurement of system order
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作者 李碧璐 李政 +1 位作者 周睿 申世飞 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期247-263,共17页
Pedestrian self-organizing movement plays a significant role in evacuation studies and architectural design.Lane formation,a typical self-organizing phenomenon,helps pedestrian system to become more orderly,the majori... Pedestrian self-organizing movement plays a significant role in evacuation studies and architectural design.Lane formation,a typical self-organizing phenomenon,helps pedestrian system to become more orderly,the majority of following behavior model and overtaking behavior model are imprecise and unrealistic compared with pedestrian movement in the real world.In this study,a pedestrian dynamic model considering detailed modelling of the following behavior and overtaking behavior is constructed,and a method of measuring the lane formation and pedestrian system order based on information entropy is proposed.Simulation and analysis demonstrate that the following and avoidance behaviors are important factors of lane formation.A high tendency of following results in good lane formation.Both non-selective following behavior and aggressive overtaking behavior cause the system order to decrease.The most orderly following strategy for a pedestrian is to overtake the former pedestrian whose speed is lower than approximately 70%of his own.The influence of the obstacle layout on pedestrian lane and egress efficiency is also studied with this model.The presence of a small obstacle does not obstruct the walking of pedestrians;in contrast,it may help to improve the egress efficiency by guiding the pedestrian flow and mitigating the reduction of pedestrian system orderliness. 展开更多
关键词 pedestrian movement lane formation information entropy order degree
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Present-day movement characteristics of the Qinghai Nanshan fault and its surrounding area from GPS observation
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作者 Yang Liu Yuxuan Qiu +5 位作者 Jialiang Liu Luyun Xiong Caijun Xu Jianghui Geng Gang Zheng Tianchen Sheng 《Geodesy and Geodynamics》 EI CSCD 2024年第2期133-141,共9页
The Qinghai Nanshan fault is a larger fault in the Northeastern Xizang Plateau.In previous studies,its movement characteristics are mainly investigated with geological and seismic observations,and the tectonic transfo... The Qinghai Nanshan fault is a larger fault in the Northeastern Xizang Plateau.In previous studies,its movement characteristics are mainly investigated with geological and seismic observations,and the tectonic transformation role of the fault on its east is not yet clear.This study uses data fusion to obtain denser GPS observations near the Qinghai Nanshan fault.Based on tectonic characteristics,we establish a block model to investigate the fault slip rate,locking degree,and slip deficit.The results show that the Qinghai Nanshan fault slip rate is characterized by sinistral and convergent movement.Both the sinistral and convergent rates display a decreasing trend from west to east.The locking degree and slip deficit are higher in the western segment(with an average of about 0.74 and 1.1 mm/a)and lower in the eastern segment.Then,we construct a strain rate field using GPS observations to analyze the regional strain characteristics.The results indicate that along the fault,the western segment shows a larger shear strain rate and negative dilation rate.Regional earthquake records show that the frequency of earthquakes is lower near the fault.The joint results suggest that the western segment may have a higher earthquake risk.In addition,the insignificant fault slip rate in the eastern segment may indicate that it does not participate in the tectonic transformation among the Riyueshan,Lajishan,and West Qinling faults. 展开更多
关键词 The Qinghai Nanshan fault movement characteristics Block model Slip rate GPS
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Modifying the progression of Parkinson's disease through movement interventions:multimodal quantification of underlying mechanisms
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作者 Manuel Bange Damian Marc Herz +2 位作者 Dumitru Ciolac Gabriel Gonzalez-Escamilla Sergiu Groppa 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第8期1651-1652,共2页
Introduction:Parkinson’s disease(PD)is the most common neurodegenerative movement disorder.The pathological hallmark is the progressive loss of dopaminergic neurons of the substantia nigra pars compacta,which is acco... Introduction:Parkinson’s disease(PD)is the most common neurodegenerative movement disorder.The pathological hallmark is the progressive loss of dopaminergic neurons of the substantia nigra pars compacta,which is accompanied by widespread alterations in the structu re and function of distributed brain networks.Togethe r,these processes cause a variety of motor symptoms such as bradykinesia,rigidity,tremor,gait disorders,or difficulties in fine motor control(Bange et al.,2022). 展开更多
关键词 alterations movement
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Muscle Strength, Lumbar Curve, Fear of Movement and Functional Disability among Patients with Lumbar Disc Herniation: A Review
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作者 G. M. Jakaria Chua Siew Kuan 《Open Journal of Therapy and Rehabilitation》 2024年第1期28-51,共24页
Introduction: Lumbar disc herniation (LDH) refers to the rupture of the fibrous annulus of the intervertebral discs. Lumbar curvature may lead to the occurrence of lumbar disc degeneration. Fear of movement may worsen... Introduction: Lumbar disc herniation (LDH) refers to the rupture of the fibrous annulus of the intervertebral discs. Lumbar curvature may lead to the occurrence of lumbar disc degeneration. Fear of movement may worsen their disc herniation and cause further pain and injury. LDH conditions impact the individuals’ quality of life, to explore the relationship between lumbar curve, muscle strength, fear of movement and functional disability among patients with LDH. Methods: An electronic search was conducted on PubMed, Medline, Science Direct, Springerlink, Google Scholar and a hand search from reference lists was reviewed. Publications were included in human studies, patients 25 - 85 years of age, original studies and published in English language journals from January 2002 to December 2023. Result: In total, 64 articles were researched through the online search engines, and 9 papers were found through manual searches of reference lists. As a result, a total of 11 articles were included for the purpose of this review. The comprehensive analysis revealed the presence of eight cross-sectional studies, two retrospective studies and one experimental study. A minimum of 25 participants and a maximum of 360 participants were included. Ten studies included both genders, only one studies included healthy adults and patients with LDH but these studies didn’t mention gender. Results showed that the factors influencing LDH can be categorized into non-modifiable factors, such as gender, age, height or others. Modifiable factors included increased BMI, DM, smoking, alcohol, employment status, lifestyle and health problems or psychology. Conclusion: Females with greater VASC may be at risk of LDH. The lumbar extensor muscles indicated a localized disc herniation or nerve root pathology in patients with LDH. The fear of movement may lead to psychological consequences and reduce functional disability among patients with LDH. 展开更多
关键词 Lumbar Disc Herniation Fear of movement Functional Disability Vertical Angle of Spinal Curvature
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Prevalence of meeting 24-Hour Movement Guidelines from pre-school to adolescence: A systematic review and meta-analysis including 387,437 participants and 23 countries 被引量:3
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作者 Miguel Angel Tapia-Serrano Javier Sevil-Serrano +3 位作者 Pedro Antonio Sanchez-Miguel Jose Francisco Lopez-Gil Mark STremblay Antonio Garcıa-Hermoso 《Journal of Sport and Health Science》 SCIE 2022年第4期427-437,共11页
Background:Meeting the 24-Hour Movement Guidelines(physical activity,screen time,and sleep duration) has been associated with positive health indicators.However,there are no previous meta-analyses that have examined t... Background:Meeting the 24-Hour Movement Guidelines(physical activity,screen time,and sleep duration) has been associated with positive health indicators.However,there are no previous meta-analyses that have examined the overall adherence to the 24-Hour Movement Guidelines from pre-school to adolescence across the world.Therefore,the main purpose of this systematic review and meta-analysis was to examine the overall(non)adherence to the 24-Hour Movement Guidelines among preschoolers,children,and adolescents worldwide.Methods:Four electronic databases(MEDLINE,Scopus,Web of Science,and Cochrane Database of Systematic Reviews) were searched for quantitative studies published in Spanish and English between January 2016 and May 2021.Studies that were conducted with apparently healthy participants and reported the overall(non)adherence to the 24-Hour Movement Guidelines in preschoolers and/or children and/or adolescents were included.Results:Sixty-three studies comprising 387,437 individuals(51% girls) aged 3-18 years from 23 countries were included.Overall,7.12%(95%confidence interval(95%CI):6.45%-7.78%) of youth met all three 24-Hour Movement Guidelines,and 19.21%(95%CI:16.73%-21.69%)met none of the 3 recommendations.Concerning sex,adherence to all recommendations was significantly lower in girls(3.75%,95%CI:3.23%-4.27%) than in boys(6.89%,95%CI:5.89%-7.89%)(p <0.001).However,there were no sex differences regarding adherence to any of the 3 individual recommendations(girls,15.66%,95%CI:8.40%-22.92%;boys,12.95%,95%CI:6.57%-19.33%).In terms of age group,adherence to the 3 recommendations was 11.26%(95%CI:8.68%-13.84%),10.31%(95%CI:7.49%-13.12%),and 2.68%(95%CI:1.78%-3.58%) in preschoolers,children,and adolescents,respectively.Conversely,8.81%(95%CI:5.97%-11.64%) of preschoolers,15.57%(95%CI:11.60%-19.54%) of children,and 28.59%(95%CI:22.42%-34.75%) of adolescents did not meet any of the recommendations.South America was the region with the lowest adherence(all:2.93%;none:31.72%).Overall adherence to the 24-Hour Movement Guidelines was positively related to country Human Development Index(β=-0.37,95%CI:-0.65 to-0.09;p=0.010).Conclusion:Most young people fail to meet the three 24-Hour Movement Guidelines,particularly adolescents,girls,and those who are from countries with a lower Human Development Index.Moreover,1 in 5 young people did not meet any of these recommendations.Therefore,these results highlight the need to develop age-and sex-specific strategies to promote these movement behaviors from the early stages of life. 展开更多
关键词 Exercise LIFESTYLE movement behaviors Sedentary behaviors YOUTH
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Earth crust vertical movements according to ITRF2000, ITRF2005,ITRF2008 and ITRF2014 coordinate systems and their comparing analysis 被引量:2
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作者 N.A.Chujkova T.G.Maximova +1 位作者 T.S.Chesnokova A.N.Grushinsky 《Geodesy and Geodynamics》 2018年第2期109-114,共6页
The analysis of Earth's crust movement vertical velocities was made both for separate regions, and averaged on regions. As input data coordinates and velocities of earth crust points, obtained in International Coo... The analysis of Earth's crust movement vertical velocities was made both for separate regions, and averaged on regions. As input data coordinates and velocities of earth crust points, obtained in International Coordinate Systems ITRF2000, ITRF2005,ITRF2008 on the base of processing radio interferometric(VLBI), laser(SLR), Doppler(DORIS) and GPS observations was used. For the purpose of global analysis all input velocity values were averaged in the x trapezoids. For filling trapezoids the spherical function expansion to N=36 was made. Expansion harmonic coefficients allowed determine the global characteristics of earth crust movements both for all Earth, and for separate hemispheres, polar and equatorial regions, continents and oceans. It appears, that polar regions were risen, and equatorial ones were lowered, that can indicate the modern Earth oblateness reduction. The constructed maps of vertical velocities were compared with obtained by us map of earth crust strain distribution. It is appeared, that regions of modern earth surface rising(Fennoscandia, Canada, Antarctica) coincide with regions of vertical extension strain, and the lowering regions-with compression regions. Simultaneously with the determination of harmonious coefficients the mean-square error of approximation for expansion of power n=1 N and power dispersion were determined. Whereas the results converge badly and dispersion increased with the n grows, hence we can concludes, that vertical movements do not characterized global earth crust movement and denotes the unrelated character of these movement. Seemingly, the main cause of such movement origin is the local seismic events(earthquake, volcanic eruption and so on). It confirms by our conclusions about correspondence of vertical strain maximal gradient(and therefore vertical velocities) map of the earthquake distribution. In work the detailed analysis of obtained results for separate Earth's regions was made. 展开更多
关键词 Crust movement Coordinate system UPLIFT
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Experimental platform for moving double-camera system based on binocular vergence eye movements
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作者 李恒宇 罗均 +2 位作者 谢少荣 李磊 李庆梅 《Journal of Shanghai University(English Edition)》 2009年第5期359-362,共4页
A control model of binocular vergence eye movements is presented. The control model can reduce blind areas caused by the double cameras in motion platform. In order to validate the model performance, an experimental p... A control model of binocular vergence eye movements is presented. The control model can reduce blind areas caused by the double cameras in motion platform. In order to validate the model performance, an experimental platform and its control system based on TMS320LF2407 are designed. The control system has its compacted configuration and high reliability. The simulation and experimental results show that the control system can realize binocular vergence movements. Compared with the conventional moving double cameras system, this new system can considerably reduce blind areas. 展开更多
关键词 BIOMIMETIC EYES VERGENCE eye movement DOUBLE cameras system experimental platform
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Theoretical Computation of Nonlinear System Equations of Heavier Pellets Movements for Two Phase Flow
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作者 Guo Jinji and Zhan ShengDept. of Applied Mechanics and Engineering, Zhongshan University, Guangzhou 510275, P.RChina 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1992年第3期59-68,共10页
This paper presents nonlinear ordinary differential equations (ODES) of the heavier pellets movement for two phase flow, which actually represent a system of equations. The usual methods of solution such as Runge -Kut... This paper presents nonlinear ordinary differential equations (ODES) of the heavier pellets movement for two phase flow, which actually represent a system of equations. The usual methods of solution such as Runge -Kutta method and it’s datum results are discussed. This paper solves ODES of general form using variable mesh-length, linearizing the nonlinear terms by finite analysis method, fuilding an iteration sequence, and amending the nonlinear terms by iteration . The conditions of convergent operation of iteration solution is checked. The movement orbit and velocity of the pellets are calculated. Analysis of research results and it’s application examples are illustrated. 展开更多
关键词 Heavier PELLETS movement Two phase flow Nonlinear system EQUATIONS Finite analysis method ITERATION approach solutions.
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Sleep-associated movement disorders and the risk of cardiovascular disease: A systematic review and metaanalysis
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作者 Zhen Fang Yao-Wu Liu +2 位作者 Li-Yan Zhao Yan Xu Feng-Xiang Zhang 《World Journal of Meta-Analysis》 2015年第3期181-187,共7页
AIM:To investigate whether an association exists between sleep-associated movement disorders and cardiovascular disease(CVD).METHODS:Several studies have observed the relationship of sleep-associated movement disorder... AIM:To investigate whether an association exists between sleep-associated movement disorders and cardiovascular disease(CVD).METHODS:Several studies have observed the relationship of sleep-associated movement disorders such as restless legs syndrome(RLS)and periodic limb movements during sleep with CVD,but the results were still contradictory.We performed an extensive literature search on Pub Med,Medline and Web of Science published from inception to December 2014.Additional studies were manually searched from bibliographies of retrieved studies.Meta-analyses were conducted with Stata version 12.0(Stata Corp,College Station,Texas).Pooled odds ratios(ORs)and 95%CIs were calculated to assess the strength of association using the random effects model.Sensitivity and subgroup analyses were performed to explore the underlying sources of heterogeneity.The publication bias was detected using Egger’s test and Begg’s test.RESULTS:A total of 781 unique citations were indentified from electronic databases and 13 articles in English were finally selected.Among these studies,nine are cohort studies;two are case-control studies;and two are cross-sectional studies.The results showed that the summary OR of CVD associated with sleepassociated movement was 1.51(95%CI:1.29-1.77)in a random-effects model.There was significant heterogeneity between individual studies(P for heterogeneity=0.005,I2=57.6%).Further analysis revealed that a large-scale cohort study may account for this heterogeneity.A significant association was also found between RLS and CVD(OR=1.54,95%CI:1.24-1.92).In a fixed-effects model,we determined a significant relationship between sleep-associatedmovement disorders and coronary artery disease(CAD)(OR=1.34,95%CI:1.16-1.54;P for heterogeneity=0.210;I2=30.0%).Our meta-analysis suggests that sleep-associated movement disorders are associated with prevalence of CVD and CAD.CONCLUSION:This finding indicates that sleep-associated movement disorders may prove to be predictive of underlying CVD. 展开更多
关键词 Sleep-associated movement disorders Restless legs syndrome Cardiovascular disease Metaanalysis Periodic limb movements during sleep
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Research on and Design of Mechanical System with Optimal Cutting Movement Trajectory of Energy-Saving Stone-Sawing Machine
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作者 WANG Ji-rong 1, LI Lan-ji 1, LI Jun 1,3, LI Hua 2, ZHONG Yun-qing 3 (1.Qingdao University, Qingdao 266071, China 2.Wendeng Foreign Economic and Trade Corp, Wendeng 264400, China 3.Qingdao University of Science and Technology, Qingdao 266042, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期140-141,共2页
The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w ear... The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w earing greatly, and the surface quality of the product is improved to the utmost extent. The design mechanism of the optimal cutting movement trajectory system structure is analyzed incisively. At the same time, the principle of the complex movement of horizontal movement and swing is researched. The optimal design scheme of th e cutting movement trajectory system structure is set up. The choice method to g et the superior value of the movement system structure is found. The mathematics function formula is established which exhibits the relationship between the par ameter of the complex movement structure and that of the system movement structu re. By the formula, the precision value of the offset can be figured out. The r ule is adapted to different types of energy-saving stone-sawing machines. The complex movement structure of horizontal movement and swing is designed to f ulfill the cutting movement. It can make the saw frame move up with the hanging pod deviating from the vertical direction. At the same time, the saw frame have a down-movement. Then the sum of the two movements is near to zero, and the saw blade and the stone can keep in touch during the whole horizontal cutting. The result is that the actual cutting efficiency is 100%. Also, when the hanging pod moves to the limited position, the saw frame can keep the original inertia, and continue to swing up. It makes the back-cutting have high energy-storing. The optimal design of the eccentricity balance wheel is done. The mathematics fo rmula for expressing the movement system structure is deduced. The calculation m ethod and formula is set up which is used to get the value of important componen ts such as offset. The choice method and formula of elasticity distortion coeffi cient is set up when the saw frame moves smoothly. It is concluded that the offs et is the key dimension to actualize the optimal cutting movement trajectory. The resolving of the technical problems discussed above offers a theoretic and technical basis for optimal design of energy-saving stone-sawing machines. 展开更多
关键词 DESIGN Research on and Design of Mechanical system with Optimal Cutting movement Trajectory of Energy-Saving Stone-Sawing Machine
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Adaptive navigation assistance based on eye movement features in virtual reality 被引量:1
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作者 Song ZHAO Shiwei CHENG 《Virtual Reality & Intelligent Hardware》 2023年第3期232-248,共17页
Background Navigation assistance is essential for users when roaming virtual reality scenes;however,the traditional navigation method requires users to manually request a map for viewing,which leads to low immersion a... Background Navigation assistance is essential for users when roaming virtual reality scenes;however,the traditional navigation method requires users to manually request a map for viewing,which leads to low immersion and poor user experience.Methods To address this issue,we first collected data on who required navigation assistance in a virtual reality environment,including various eye movement features,such as gaze fixation,pupil size,and gaze angle.Subsequently,we used the boosting-based XGBoost algorithm to train a prediction model and finally used it to predict whether users require navigation assistance in a roaming task.Results After evaluating the performance of the model,the accuracy,precision,recall,and F1-score of our model reached approximately 95%.In addition,by applying the model to a virtual reality scene,an adaptive navigation assistance system based on the real-time eye movement data of the user was implemented.Conclusions Compared with traditional navigation assistance methods,our new adaptive navigation assistance method could enable the user to be more immersive and effective while roaming in a virtual reality(VR)environment. 展开更多
关键词 Eye movement NAVIGATION Human-computer interaction Virtual reality Eye tracking
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Development of Portable Monitoring System for Real-Time Detection of Fetal Movement
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作者 Qifeng Jiang Bin Gao Yang Li 《Advances in Bioscience and Biotechnology》 2018年第8期380-389,共10页
Effective fetal monitoring is an important guarantee for fetal health and early treatment. Fetal movement is one of critical indicators of fetal monitoring, which plays an important role in fetal health. Counting the ... Effective fetal monitoring is an important guarantee for fetal health and early treatment. Fetal movement is one of critical indicators of fetal monitoring, which plays an important role in fetal health. Counting the number of fetal movement by pregnant women is a traditional method for long-term monitoring. However, there are many defects in pregnant women’s feeling count, which cannot meet the accurate requirements of modern perinatal medicine. With the rapid development of biological and electronic technology, various sensors are used to probe the fetal dynamic monitoring, but not on fetal movement. This research proposes a monitoring method for fetal movement via three electrodes. Briefly: first, three electrodes are used to extract electrical signals in the abdomen of pregnant women;second, these signals are amplified and filtered;third, A/D converter with microprocessor is used to make analog digital conversion, which can be stored in the SD card under the control of the microprocessor;finally, the SD card data are processed by computer software and the fetal movement information is analyzed. 展开更多
关键词 FETAL movement MONITORING ELECTROCARDIOGRAM ELECTRODE
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Development and Testing of an Automatic Turning Movement Identification System at Signalized Intersections
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作者 Kun Xu Ping Yi +1 位作者 Chun Shao Jialei Mao 《Journal of Transportation Technologies》 2013年第4期241-246,共6页
Vehicle turning movement data from signalized intersections is utilized for numerous applications in the field of transportation. Such applications include real-time adaptive signal control, dynamic traffic assignment... Vehicle turning movement data from signalized intersections is utilized for numerous applications in the field of transportation. Such applications include real-time adaptive signal control, dynamic traffic assignment, and traffic demand estimation. However, it is very time consuming and costly to obtain vehicle turning movement information manually. Previous efforts to simplify this process were focused on solving the problem using an O-D matrix, but this method proved to be inaccurate and unreliable with the existing data acquisition system. Another study involved the identification of vehicle turning movements from the detector information, but the presence of shared lanes led to uncertainties in vehicle matching, thus limiting application of the method only to intersections without shared lanes. In light of those unsuccessful attempts, this paper develops and tests a system called the Automatic Turning Movement Identification System (ATMIS), which estimates vehicle turning movements at a signalized intersection in real time, regardless of its geometry. The results from lab experiments as well as a field test show that the algorithm is very promising and may potentially be expanded for field applications. 展开更多
关键词 TURNING movement Identification Signalized INTERSECTION DETECTOR and Detection Vehicle MATCHING LAB Experiment and Field Test
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Stress and Strain Accumulation Due to a Long Dip-Slip Fault Movement in an Elastic-Layer over a Viscoelastic Half Space Model of the Lithosphere-Asthenosphere System
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作者 Sanjay Sen Subrata Kr. Debnath 《International Journal of Geosciences》 2013年第3期549-557,共9页
Most of the earthquake faults in North-East India, China, mid Atlantic-ridge, the Pacific seismic belt and Japan are found to be predominantly dip-slip in nature. In the present paper a dip-slip fault is taken situate... Most of the earthquake faults in North-East India, China, mid Atlantic-ridge, the Pacific seismic belt and Japan are found to be predominantly dip-slip in nature. In the present paper a dip-slip fault is taken situated in an elastic layer over a viscoelastic half space representing the lithosphere-asthenosphere system. A movement of the dip-slip nature across the fault occurs when the accumulated stress due to various tectonic reasons e.g. mantle convection etc., exceeds the local friction and cohesive forces across the fault. The movement is assumed to be slipping in nature, expressions for displacements, stresses and strains are obtained by solving associated boundary value problem with the help of integral transformation and Green’s function method and a suitable numerical methods is used for computation. A detailed study of these expressions may give some ideas about the nature of stress accumulation in the system, which in turn will be helpful in formulating an earthquake prediction programme. 展开更多
关键词 Aseismic Period Dip-Slip Fault Earthquake Prediction MANTLE Convection Plate movements Stress ACCUMULATION TECTONIC Process Viscoelastic-Layered Model
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SIMULATION OF STRATA MOVEMENTS DUE TO UNDERGROUND MINING USING AN AUTOMATED MEASUREMENT SYSTEM FOR EQUIVALENT MATERIAL MODELING FACILITY
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作者 张玉卓 YoginderP.Chugh 《Journal of Coal Science & Engineering(China)》 1996年第1期10-15,共6页
Strata movement simulation was conducted in an equivalent material modeling facility developed by the Department of Mining Engineering, Southern Illinois University at Carbondale, under U. S. Bureau of Mines contracts... Strata movement simulation was conducted in an equivalent material modeling facility developed by the Department of Mining Engineering, Southern Illinois University at Carbondale, under U. S. Bureau of Mines contracts. An innovative displacement measurement system called videogrammetric system was developed and utilized for recording, measuring and analyzing the deformation and failure process of the models. A room and pillar mining and a longwall mining prototypes were studied in the modeling. Study found that weak floor of coal seam plays an important role in pillar stability and therefore the overburden movements. 展开更多
关键词 地表移动 自动测量系统 计算机模拟 煤矿 机械模型
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Three-dimensional assessment of movement patterns of Sichuan snub-nosed monkeys affected by habitat structure in temperate forests
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作者 Hai-Tao Yang Shun Li +8 位作者 Rong Hou Wen-Tao Song Yan-Wen Fu Yong-Bo Li Xiao-Wei Wang Gang He Colin A.Chapman Qing-Hua Guo Bao-Guo Li 《Zoological Research》 SCIE CAS CSCD 2023年第2期361-365,共5页
DEAR EDITOR,Movement patterns can reflect species-specific characteristics of individuals and animal groups at a given scale. Accurate three-dimensional(3D) assessment can quantify the relationship between movement pa... DEAR EDITOR,Movement patterns can reflect species-specific characteristics of individuals and animal groups at a given scale. Accurate three-dimensional(3D) assessment can quantify the relationship between movement patterns of an animal and its unique habitat. Here, we evaluated the effects of habitat structure on movement patterns of the golden snub-nosed monkey(Rhinopithecus roxellana). We used airborne light detection and ranging(LiDAR) to map the 3D structure of the temperate forest in the Qinling Mountains(Shaanxi, China). 展开更多
关键词 HABITAT movement TEMPERATE
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Image-Aided Analysis of Ballast Particle Movement Along a High-Speed Railway
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作者 Xuecheng Bian Wenqing Cai +2 位作者 Zheng Luo Chuang Zhao Yunmin Chen 《Engineering》 SCIE EI CAS CSCD 2023年第8期161-177,共17页
As a core infrastructure of high-speed railways,ballast layers constituted by graded crushed stones feature noteworthy particle movement compared with normal railways,which may cause excessive settlement and have detr... As a core infrastructure of high-speed railways,ballast layers constituted by graded crushed stones feature noteworthy particle movement compared with normal railways,which may cause excessive settlement and have detrimental effects on train operation.However,the movement behavior remains ambiguous due to a lack of effective measurement approaches and analytical methods.In this study,an image-aided technique was developed in a full-scale model test using digital cameras and a colorbased identification approach.A total of 1274 surface ballast particles were manually dyed by discernible colors to serve as tracers in the test.The movements of the surface ballast particles were tracked using the varied pixels displaying tracers in the photos that were intermittently taken during the test in the perpendicular direction.The movement behavior of ballast particles under different combinations of train speeds and axle loads was quantitatively evaluated.The obtained results indicated that the surface ballast particle movements were slight,mainly concentrated near sleepers under low-speed train loads and greatly amplified and extended to the whole surface when the train speed reached 360 km.h-1.Additionally,the development of ballast particle displacement statistically resembled its rotation.Track vibration contributed to the movements of ballast particles,which specifically were driven by vertical acceleration near the track center and horizontal acceleration at the track edge.Furthermore,the development trends of ballast particle movements and track settlement under long-term train loading were similar,and both stabilized at nearly the same time.The track performance,including the vibration characteristics,accumulated settlement,and sleeper support stiffness,was determined to be closely related to the direction and distribution of ballast particle flow,which partly deteriorated under high-speed train loads. 展开更多
关键词 High-speed railway Full-scale model test Image-aided technique Ballast particle movement Track vibration Accumulated settlement
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Prediction of landslide block movement based on Kalman filtering data assimilation method
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作者 LIU Yong XU Qing-jie +2 位作者 LI Xing-rui YANG Ling-feng XU Hong 《Journal of Mountain Science》 SCIE CSCD 2023年第9期2680-2691,共12页
Compared with the study of single point motion of landslides,studying landslide block movement based on data from multiple monitoring points is of great significance for improving the accurate identification of landsl... Compared with the study of single point motion of landslides,studying landslide block movement based on data from multiple monitoring points is of great significance for improving the accurate identification of landslide deformation.Based on the study of landslide block,this paper regarded the landslide block as a rigid body in particle swarm optimization algorithm.The monitoring data were organized to achieve the optimal state of landslide block,and the 6-degree of freedom pose of the landslide block was calculated after the regularization.Based on the characteristics of data from multiple monitoring points of landslide blocks,a prediction equation for the motion state of landslide blocks was established.By using Kalman filtering data assimilation method,the parameters of prediction equation for landslide block motion state were adjusted to achieve the optimal prediction.This paper took the Baishuihe landslide in the Three Gorges reservoir area as the research object.Based on the block segmentation of the landslide,the monitoring data of the Baishuihe landslide block were organized,6-degree of freedom pose of block B was calculated,and the Kalman filtering data assimilation method was used to predict the landslide block movement.The research results showed that the proposed prediction method of the landslide movement state has good prediction accuracy and meets the expected goal.This paper provides a new research method and thinking angle to study the motion state of landslide block. 展开更多
关键词 Landslide block movement state 6-degree of freedom pose Kalman filtering Data assimilation Baishuihe landslide
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Design of Rehabilitation Training Device for Finger-Tapping Movement Based on Trajectory Extraction Experiment
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作者 刘志辉 孔繁磊 王婷婷 《Journal of Donghua University(English Edition)》 CAS 2023年第4期384-396,共13页
Patients with stroke, tendon injury and cardiovascular disease commonly have the sequelae of hand dysfunction which seriously affects the patients’ ability in daily life. Previous studies have found that the function... Patients with stroke, tendon injury and cardiovascular disease commonly have the sequelae of hand dysfunction which seriously affects the patients’ ability in daily life. Previous studies have found that the function of finger-tapping movement accounts for 80% of the hand function, and the recovery of the motor ability of the finger-tapping can greatly improve the patients’ self-care ability. Therefore, a rehabilitation training device to restore the finger-tapping movement is designed. In the study, anthropometry was applied to measure the dynamic and static dimensions of human hands in the finger-tapping movement. Subjects were selected according to the selected size range, and an experimental platform was built. Sampling points were set at key positions of index fingers and thumbs, and characteristic points of coronal planes and sagittal planes were recorded at a frequency of 10 frames per second. MATLAB was used to optimize the fitting of the scatter plot, and the fitted spatial curve parameters were input into the modeling software to establish the joint motion trajectory model and assist the design of rehabilitation training devices. It is proved that the device is ergonomic, and can effectively achieve the finger-tapping movement rehabilitation training of patients. 展开更多
关键词 movement therapy finger-tapping movement ANTHROPOMETRY stroke ERGONOMICS
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