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Evaluation of slope stability through rock mass classification and kinematic analysis of some major slopes along NH-1A from Ramban to Banihal, North Western Himalayas 被引量:1
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作者 Amit Jaiswal A.K.Verma T.N.Singh 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期167-182,共16页
The network of Himalayan roadways and highways connects some remote regions of valleys or hill slopes,which is vital for India’s socio-economic growth.Due to natural and artificial factors,frequency of slope instabil... The network of Himalayan roadways and highways connects some remote regions of valleys or hill slopes,which is vital for India’s socio-economic growth.Due to natural and artificial factors,frequency of slope instabilities along the networks has been increasing over last few decades.Assessment of stability of natural and artificial slopes due to construction of these connecting road networks is significant in safely executing these roads throughout the year.Several rock mass classification methods are generally used to assess the strength and deformability of rock mass.This study assesses slope stability along the NH-1A of Ramban district of North Western Himalayas.Various structurally and non-structurally controlled rock mass classification systems have been applied to assess the stability conditions of 14 slopes.For evaluating the stability of these slopes,kinematic analysis was performed along with geological strength index(GSI),rock mass rating(RMR),continuous slope mass rating(CoSMR),slope mass rating(SMR),and Q-slope in the present study.The SMR gives three slopes as completely unstable while CoSMR suggests four slopes as completely unstable.The stability of all slopes was also analyzed using a design chart under dynamic and static conditions by slope stability rating(SSR)for the factor of safety(FoS)of 1.2 and 1 respectively.Q-slope with probability of failure(PoF)1%gives two slopes as stable slopes.Stable slope angle has been determined based on the Q-slope safe angle equation and SSR design chart based on the FoS.The value ranges given by different empirical classifications were RMR(37-74),GSI(27.3-58.5),SMR(11-59),and CoSMR(3.39-74.56).Good relationship was found among RMR&SSR and RMR&GSI with correlation coefficient(R 2)value of 0.815 and 0.6866,respectively.Lastly,a comparative stability of all these slopes based on the above classification has been performed to identify the most critical slope along this road. 展开更多
关键词 Rock mass classification kinematic analysis Slope stability Himalayan road Static and dynamic conditions
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Configuration and Kinematics of a 3-DOF Generalized Spherical Parallel Mechanism for Ankle Rehabilitation
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作者 Jianjun Zhang Shuai Yang +2 位作者 Chenglei Liu Xiaohui Wang Shijie Guo 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第1期176-188,共13页
The kinematic equivalent model of an existing ankle-rehabilitation robot is inconsistent with the anatomical structure of the human ankle,which influences the rehabilitation effect.Therefore,this study equates the hum... The kinematic equivalent model of an existing ankle-rehabilitation robot is inconsistent with the anatomical structure of the human ankle,which influences the rehabilitation effect.Therefore,this study equates the human ankle to the UR model and proposes a novel three degrees of freedom(3-DOF)generalized spherical parallel mechanism for ankle rehabilitation.The parallel mechanism has two spherical centers corresponding to the rotation centers of tibiotalar and subtalar joints.Using screw theory,the mobility of the parallel mechanism,which meets the requirements of the human ankle,is analyzed.The inverse kinematics are presented,and singularities are identified based on the Jacobian matrix.The workspaces of the parallel mechanism are obtained through the search method and compared with the motion range of the human ankle,which shows that the parallel mechanism can meet the motion demand of ankle rehabilitation.Additionally,based on the motion-force transmissibility,the performance atlases are plotted in the parameter optimal design space,and the optimum parameter is obtained according to the demands of practical applications.The results show that the parallel mechanism can meet the motion requirements of ankle rehabilitation and has excellent kinematic performance in its rehabilitation range,which provides a theoretical basis for the prototype design and experimental verification. 展开更多
关键词 Ankle rehabilitation Parallel mechanism kinematic analysis Parameter optimization
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Kinematic deformation and intensity assessment of the 2021 Maduo M_(S)7.4 earthquake in Qinghai revealed by high-frequency GNSS
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作者 Yu Li Yuebing Wang +2 位作者 Lijiang Zhao Hongbo Shi Pingping Wang 《Geodesy and Geodynamics》 EI CSCD 2024年第3期230-240,共11页
Rapid acquisition of the kinematic deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue,disaster assessment,and future seismic risk research.The advance... Rapid acquisition of the kinematic deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue,disaster assessment,and future seismic risk research.The advancement of GNSS observation and data processing makes it play an important role in this field,especially the high-frequency GNSS.We used the differential positioning method to calculate the 1 HZ GNSS data from 98 sites within 1000 km of the M_(S)7.4 Maduo earthquake epicenter.The kinematic deformation field and the distribution of the seismic intensity by using the peak ground velocity derived from displacement waveforms were obtained.The results show that:1)Horizontal coseismic response deformation levels ranging from 25 mm to 301 mm can be observed within a 1000 km radius from the epicenter.Coseismic response deformation on the east and west sides shows bilateral asymmetry,which markedly differs from the symmetry presented by surface rupture.2)The seismic intensity obtained through high-frequency GNSS and field investigations exhibits good consistency of the scope and orientation in the high seismic intensity area,although the former is generally slightly smaller than the latter.3)There may exist obstacles on the eastern side of the seismogenic fault.The Maduo earthquake induced a certain tectonic stress loading effect on the western Kunlun Pass-Jiangcuo fault(KPJF)and Maqin-Maqu segment,resulting in higher seismic risk in the future. 展开更多
关键词 Maduo earthquake High-frequency GNSS kinematic deformation Seismic intensity
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The Early Mesozoic NE-SW Extensional Model and Exhumation Processes at the Southeastern Margin of the Central Asian Orogenic Belt:Insights from the Strain and Kinematic Vorticity Analysis of the Sonid Zuoqi Ductile Detachment Zone
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作者 LI Jianbo SONG Zhijie +1 位作者 LEI Hengcong ZENG Tao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第5期1141-1153,共13页
The Sonid Zuoqi ductile detachment zone is located at the southeastern margin of the Central Asian orogenic belt(CAOB),striking EW and dipping to the S.The major rock type of the Sonid Zuoqi ductile detachment zone is... The Sonid Zuoqi ductile detachment zone is located at the southeastern margin of the Central Asian orogenic belt(CAOB),striking EW and dipping to the S.The major rock type of the Sonid Zuoqi ductile detachment zone is mylonite derived from granite.The sequence of mylonite features is:(1)S and C foliations of mylonite,and(2)extensional crenulation cleavage(ecc)or C′and the kinematic vorticity(Wk)value changed from 0.70 to 0.95 and from 0.37 to 0.69,respectively;the strain type of the mylonites within the Sonid Zuoqi ductile detachment zone is compressional to planar strain.The strong deformation mylonite and Halatu plutons yielded a zircon U-Pb age of 244 Ma and a zircon(U-Th)/He age of 214 Ma,respectively.Based on the strain and kinematic vorticity analysis,together with the zircon U-Pb and zircon(U-Th)/He ages and the regional tectonic background,the study area experienced three stage evolution:tangential simpleshear(244 Ma),simple-shear-dominated general shear represented by upper crustal extension(224 Ma)and pure-shear-dominated general shear represented by the Halatu pluton doming(214 Ma),which constrained the early Mesozoic NE-SW crustal extension at the southeastern margin of the CAOB.This NE-SW extension probably originated from the postorogenic extensional collapse of the CAOB,subsequent exhumation being controlled by the far afield effects of the closure of the Mongol-Okhotsk belt. 展开更多
关键词 STRAIN simple shear pure shear kinematic vorticity ductile detachment zone
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Kinematics ofmandibular advancement devices(MADs):Why do some MADs move the lower jaw backward duringmouth opening?
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作者 Juan A.Cabrera Alex Bataller +1 位作者 Sergio Postigo Marcos García 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第5期637-650,共14页
Mandibular advancement devices(MADs)are widely used treatments for obstructive sleep apnea.MADs function by advancing the lower jaw to open the upper airway.To increase patient comfort,most patients allow the mouth to... Mandibular advancement devices(MADs)are widely used treatments for obstructive sleep apnea.MADs function by advancing the lower jaw to open the upper airway.To increase patient comfort,most patients allow the mouth to be opened.However,not all systems maintain the lower jaw in a forward position during mouth opening,which results in the production of a retrusion that favors the collapse of the upper airway.Furthermore,the kinematic behavior of the mechanism formed by the mandible-device assembly depends on jaw morphology.This means that,during mouth opening,some devices cause lower jaw protrusion in some patients,but cause its retraction in others.In this study,we report the behavior of well-known devices currently on themarket.To do so,we developed a kinematic model of the lower jawdevice assembly.Thismodelwas validated for all devices analyzed using a high-resolution camera system.Our results show that some of the devices analyzed here did not produce the correct behavior during patient mouth opening. 展开更多
关键词 Mandibular advancement devices Lower jaw kinematics Sleep apnea
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Case Studies of the Microphysical and Kinematic Structure of Summer Mesoscale Precipitation Clouds over the Eastern Tibetan Plateau
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作者 Shuo JIA Jiefan YANG Hengchi LEI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期97-114,共18页
Three cases of microphysical characteristics and kinematic structures in the negative temperature region of summer mesoscale cloud systems over the eastern Tibetan Plateau(TP)were investigated using X-band dual-polari... Three cases of microphysical characteristics and kinematic structures in the negative temperature region of summer mesoscale cloud systems over the eastern Tibetan Plateau(TP)were investigated using X-band dual-polarization radar.The time-height series of radar physical variables and mesoscale horizontal divergence δderived by quasi-vertical profiles(QVPs)indicated that the dendritic growth layer(DGL,-20°C to-10°C)was ubiquitous,with large-value zones of K_(DP)(specific differential phase),Z_(DR)(differential reflectivity),or both,and corresponded to various dynamic fields(ascent or descent).Ascents in the DGL of cloud systems with vigorous vertical development were coincident with large-value zones of Z_(DR),signifying ice crystals with a large axis ratio,but with no obvious large values of K_(DP),which differs from previous findings.It is speculated that ascent in the DGL promoted ice crystals to undergo further growth before sinking.If there was descent in the DGL,a high echo top corresponded to large values of K_(DP),denoting a large number concentration of ice crystals;but with the echo top descending,small values of K_(DP) formed.This is similar to previous results and reveals that a high echo top is conducive to the generation of ice crystals.When ice particles fall to low levels(-10℃ to 0℃),they grow through riming,aggregation,or deposition,and may not be related to the kinematic structure.It is important to note that this study was only based on a limited number of cases and that further research is therefore needed. 展开更多
关键词 Tibetan Plateau polarimetric variables MICROPHYSICS dendritic growth layer kinematic structure aggregation RIMING
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An approach for determination of lateral limit angle in kinematic planar sliding analysis for rock slopes
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作者 Xiaojuan Yang Jie Hu +1 位作者 Honglei Sun Jun Zheng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1305-1314,共10页
Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar slid... Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar sliding kinematic analysis is significantly influenced by the value assigned to the lateral limit angleγlim.However,the assignment ofγlim is currently used generally based on an empirical criterion.This study aims to propose an approach for determining the value ofγlim in deterministic and probabilistic kinematic planar sliding analysis.A new perspective is presented to reveal thatγlim essentially influences the probability of forming a potential planar sliding block.The procedure to calculate this probability is introduced using the block theory method.It is found that the probability is correlated with the number of discontinuity sets presented in rock masses.Thus,different values ofγlim for rock masses with different sets of discontinuities are recommended in both probabilistic and deterministic planar sliding kinematic analyses;whereas a fixed value ofγlim is commonly assigned to different types of rock masses in traditional method.Finally,an engineering case was used to compare the proposed and traditional kinematic analysis methods.The error rates of the traditional method vary from 45%to 119%,while that of the proposed method ranges between 1%and 17%.Therefore,it is likely that the proposed method is superior to the traditional one. 展开更多
关键词 kinematic analysis Block theory Planar sliding Lateral limit angle Rock slope
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Kinematic-mapping-model-guided analysis and optimization of 2-PSS&1-RR circular-rail parallel mechanism for fully steerable phased array antennas
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作者 Guodong Tan Xiangfei Meng +4 位作者 Xuechao Duan Lulu Cheng Dingchao Niu Shuai He Dan Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第8期136-154,共19页
This paper presents a systematic methodology for analyzing and optimizing an innovative antenna mount designed for phased array antennas, implemented through a novel 2-PSS&1-RR circular-rail parallel mechanism. In... This paper presents a systematic methodology for analyzing and optimizing an innovative antenna mount designed for phased array antennas, implemented through a novel 2-PSS&1-RR circular-rail parallel mechanism. Initially, a comparative motion analysis between the 3D model of the mount and its full-scale prototype is conducted to validate effectiveness. Given the inherent complexity, a kinematic mapping model is established between the mount and the crank-slider linkage, providing a guiding framework for subsequent analysis and optimization. Guided by this model, feasible inverse and forward solutions are derived, enabling precise identification of stiffness singularities. The concept of singularity distance is thus introduced to reflect the structural stiffness of the mount. Subsequently, also guided by the mapping model, a heuristic algorithm incorporating two backtracking procedures is developed to reduce the mount's mass. Additionally, a parametric finite-element model is employed to explore the relation between singularity distance and structural stiffness. The results indicate a significant reduction(about 16%) in the antenna mount's mass through the developed algorithm, while highlighting the singularity distance as an effective stiffness indicator for this type of antenna mount. 展开更多
关键词 Innovative antenna mount Circular rail kinematic mapping model Crank-slider linkage Stiffness singularity BACKTRACKING
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Acute effect of foot strike patterns on in vivo tibiotalar and subtalar joint kinematics during barefoot running
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作者 Dongqiang Ye Lu Li +4 位作者 Shen Zhang Songlin Xiao Xiaole Sun Shaobai Wang Weijie Fu 《Journal of Sport and Health Science》 SCIE CSCD 2024年第1期108-117,共10页
Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patte... Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics.However,technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns(RFS and FFS,respectively).This study uses a high-speed dual fluoroscopic imaging system(DFIS)to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics.Methods:Fifteen healthy male recreational runners underwent foot computed tomography scanning for the construction of 3-dimensional models.A high-speed DFIS(100 Hz)was used to collect 6 degrees of freedom kinematics for participants’tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition.Results:Compared with RFS,FFS exhibited greater internal rotation at 0%-20%of the stance phase in the tibiotalar joint.The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS(p<0.001,Cohen’s d=0.92).RFS showed more dorsiflexion at 0%-20%of the stance phase in the tibiotalar joint than FFS.RFS also presented a larger anterior translation(p<0.001,Cohen’s d=1.28)in the subtalar joint at i nitial contact than FFS.Conclusion:Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance.The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RF S and FFS during running. 展开更多
关键词 Foot strike patterns High-speed dual fluoroscopic imaging system In vivo kinematics Running
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Kinematic calibration under the expectation maximization framework for exoskeletal inertial motion capture system
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作者 QIN Weiwei GUO Wenxin +2 位作者 HU Chen LIU Gang SONG Tainian 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期769-779,共11页
This study presents a kinematic calibration method for exoskeletal inertial motion capture (EI-MoCap) system with considering the random colored noise such as gyroscopic drift.In this method, the geometric parameters ... This study presents a kinematic calibration method for exoskeletal inertial motion capture (EI-MoCap) system with considering the random colored noise such as gyroscopic drift.In this method, the geometric parameters are calibrated by the traditional calibration method at first. Then, in order to calibrate the parameters affected by the random colored noise, the expectation maximization (EM) algorithm is introduced. Through the use of geometric parameters calibrated by the traditional calibration method, the iterations under the EM framework are decreased and the efficiency of the proposed method on embedded system is improved. The performance of the proposed kinematic calibration method is compared to the traditional calibration method. Furthermore, the feasibility of the proposed method is verified on the EI-MoCap system. The simulation and experiment demonstrate that the motion capture precision is significantly improved by 16.79%and 7.16%respectively in comparison to the traditional calibration method. 展开更多
关键词 human motion capture kinematic calibration EXOSKELETON gyroscopic drift expectation maximization(EM)
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Gait Kinematic Analysis Facilitates Rapid Early Recovery Following Total Knee Arthroplasty
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作者 Shiluan Liu Zhengyu Cao +4 位作者 Saijiao Lan Chongjing Zhang Lin Pan Wenjin Luo Jian Li 《Journal of Biosciences and Medicines》 2024年第10期328-338,共11页
Objective: To explore gait kinematics analysis and evaluate the surgical efficacy of total knee arthroplasty (TKA), as well as its guiding significance for postoperative rehabilitation. Method: Fifty patients admitted... Objective: To explore gait kinematics analysis and evaluate the surgical efficacy of total knee arthroplasty (TKA), as well as its guiding significance for postoperative rehabilitation. Method: Fifty patients admitted to TKA treatment for knee osteoarthritis from December 2022 to July 2023 were included, which were divided into an intervention group (gait kinematics analysis group, n = 25) and a control group (conventional rehabilitation program group, n = 25). All patients underwent HSS score and KSS score before surgery (T0), 1 month after surgery (T1), 3 months after surgery (T2), and 6 months after surgery (T3). The intervention group underwent gait kinematics analysis at 1 month after surgery (T1) and 3 months after surgery (T2). Two groups measured the hip knee ankle angle (HKA), distal femoral lateral angle (LDFA), and proximal tibial medial angle (MPTA) on knee joint radiographs before and after surgery. Results: There was no significant difference in general information, preoperative imaging parameters, and functional scores between the two groups of patients. There was no significant difference in functional scores and postoperative prosthesis alignment between the two groups of patients in the first month after surgery. The intervention group showed a significant decrease in gait kinematic scores in the first month, with hip joint scores being particularly prominent (P 0.05). Conclusion: Gait kinematic analysis is helpful in evaluating the postoperative efficacy of TKA and can guide early and rapid recovery after TKA. 展开更多
关键词 Gait kinematic Analysis Total Knee Arthroplasty
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Novel thick-target inverse kinematics method for the astrophysical ^(12)C+^(12)C fusion reaction
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作者 Wei-Ke Nan You-Bao Wang +20 位作者 Yao-De Sheng Jun Su Yu-Qiang Zhang Lu-Yang Song Yang-Ping Shen Fu-Qiang Cao Chen Chen Chao Dong Yun-Ju Li Zhi-Hong Li Gang Lian Wei Nan Qiang Wang Na Song Sheng-Quan Yan Seng Zeng Qi-Wen Fan Hao Zhang Ming-Hao Zhu Bing Guo Wei-Ping Liu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第11期237-243,共7页
The ^(12)C+^(12)C fusion is one of the most important reactions in modern nuclear astrophysics.The trend and magnitude of the reaction rate within the Gamow window strongly influence various astrophysical processes.Ho... The ^(12)C+^(12)C fusion is one of the most important reactions in modern nuclear astrophysics.The trend and magnitude of the reaction rate within the Gamow window strongly influence various astrophysical processes.However,direct measurement of this reaction is extremely difficult,which makes it necessary to develop indirect methods.In this study,the ^(23)Na+p reaction system was used to study the compound nucleus ^(24)Mg.We employed a thick-target inverse kinematics method combined with the-charged-particle coincidence technique to measure the proton andexit channels of ^(24)Mg.Technical details of the ^(23)Na+p thick-target inverse kinematics experiment and analysis are presented herein. 展开更多
关键词 Nuclear astrophysics ^(12)C+^(12)C Thick-target inverse kinematics method -charged particle coincidence
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Mid-term outcomes of a kinematically designed cruciate retaining total knee arthroplasty
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作者 Jonathan L Katzman Akram A Habibi +4 位作者 Muhammad A Haider Casey Cardillo Ivan Fernandez-Madrid Morteza Meftah Ran Schwarzkopf 《World Journal of Orthopedics》 2024年第2期118-128,共11页
BACKGROUND Advances in implant material and design have allowed for improvements in total knee arthroplasty(TKA)outcomes.A cruciate retaining(CR)TKA provides the least constraint of TKA designs by preserving the nativ... BACKGROUND Advances in implant material and design have allowed for improvements in total knee arthroplasty(TKA)outcomes.A cruciate retaining(CR)TKA provides the least constraint of TKA designs by preserving the native posterior cruciate ligament.Limited research exists that has examined clinical outcomes or patient reported outcome measures(PROMs)of a large cohort of patients undergoing a CR TKA utilizing a kinematically designed implant.It was hypothesized that the studied CR Knee System would demonstrate favorable outcomes and a clinically significant improvement in pain and functional scores.AIM To assess both short-term and mid-term clinical outcomes and PROMs of a novel CR TKA design.METHODS A retrospective,multi-surgeon study identified 255 knees undergoing a TKA utilizing a kinematically designed CR Knee System(JOURNEY™II CR;Smith and Nephew,Inc.,Memphis,TN)at an urban,academic medical institution between March 2015 and July 2021 with a minimum of two-years of clinical follow-up with an orthopedic surgeon.Patient demographics,surgical information,clinical outcomes,and PROMs data were collected via query of electronic medical records.The PROMs collected in the present study included the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement(KOOS JR)and Patient-Reported Outcomes Measurement Information System(PROMIS■)scores.The significance of improvements in mean PROM scores from preoperative scores to scores collected at six months and two-years postoperatively was analyzed using Independent Samples t-tests.RESULTS Of the 255 patients,65.5%were female,43.8%were White,and patients had an average age of 60.6 years.Primary osteoarthritis(96.9%)was the most common primary diagnosis.The mean surgical time was 105.3 minutes and mean length of stay was 2.1 d with most patients discharged home(92.5%).There were 18 emergency department(ED)visits within 90 d of surgery resulting in a 90 d ED visit rate of 7.1%,including a 2.4%orthopedic-related ED visit rate and a 4.7%non-orthopedic-related ED visit rate.There were three(1.2%)hospital readmissions within 90 d postoperatively.With a mean time to latest follow-up of 3.3 years,four patients(1.6%)required revision,two for arthrofibrosis,one for aseptic femoral loosening,and one for peri-prosthetic joint infection.There were significant improvements in KOOS JR,PROMIS Pain Intensity,PROMIS Pain Interference,PROMIS Mobility,and PROMIS Physical Health from preoperative scores to six month and two-year postoperative scores.CONCLUSION The evaluated implant is an effective,novel design offering excellent outcomes and low complication rates.At a mean follow up of 3.3 years,four patients required revisions,three aseptic and one septic,resulting in an overall implant survival rate of 98.4%and an aseptic survival rate of 98.8%.The results of our study demonstrate the utility of this kinematically designed implant in the setting of primary TKA. 展开更多
关键词 Total knee arthroplasty Cruciate retaining kinematic design SURVIVORSHIP Bearing material Prosthetic design Clinical outcomes Patient-reported outcome measures
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3-Dimensional Kinematic Comparison of Arm Movements between an Individual with NGLY1 Deficiency and a Neurotypical Individual
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作者 Charles S. Layne Christopher A. Malaya +6 位作者 Brock Futrell Dacia Martinez Diaz Christian Alfaro Hannah E. Gustafson Subhalakshmi Chandrasekaran Rhea M. Phatak Bernhard Suter 《Case Reports in Clinical Medicine》 2024年第4期122-146,共25页
NGLY1 Deficiency is an ultra-rare autosomal recessively inherited disorder. Characteristic symptoms include among others, developmental delays, movement disorders, liver function abnormalities, seizures, and problems ... NGLY1 Deficiency is an ultra-rare autosomal recessively inherited disorder. Characteristic symptoms include among others, developmental delays, movement disorders, liver function abnormalities, seizures, and problems with tear formation. Movements are hyperkinetic and may include dysmetric, choreo-athetoid, myoclonic and dystonic movement elements. To date, there have been no quantitative reports describing arm movements of individuals with NGLY1 Deficiency. This report provides quantitative information about a series of arm movements performed by an individual with NGLY1 Deficiency and an aged-matched neurotypical participant. Three categories of arm movements were tested: 1) open ended reaches without specific end point targets;2) goal-directed reaches that included grasping an object;3) picking up small objects from a table placed in front of the participants. Arm movement kinematics were obtained with a camera-based motion analysis system and “initiation” and “maintenance” phases were identified for each movement. The combination of the two phases was labeled as a “complete” movement. Three-dimensional analysis techniques were used to quantify the movements and included hand trajectory pathlength, joint motion area, as well as hand trajectory and joint jerk cost. These techniques were required to fully characterize the movements because the NGLY1 individual was unable to perform movements only in the primary plane of progression instead producing motion across all three planes of movement. The individual with NGLY1 Deficiency was unable to pick up objects from a table or effectively complete movements requiring crossing the midline. The successfully completed movements were analyzed using the above techniques and the results of the two participants were compared statistically. Almost all comparisons revealed significant differences between the two participants, with a notable exception of the 3D initiation area as a percentage of the complete movement. The statistical tests of these measures revealed no significant differences between the two participants, possibly suggesting a common underlying motor control strategy. The 3D techniques used in this report effectively characterized arm movements of an individual with NGLY1 deficiency and can be used to provide information to evaluate the effectiveness of genetic, pharmacological, or physical rehabilitation therapies. 展开更多
关键词 NGLY1 Deficiency Developmental Disorders kinematicS 3 Dimensional Analyses
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基于IMU-LiDAR紧耦合的煤矿防冲钻孔机器人定位导航方法 被引量:2
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作者 司垒 王忠宾 +4 位作者 魏东 顾进恒 闫海峰 谭超 朱远胜 《煤炭学报》 EI CAS CSCD 北大核心 2024年第4期2179-2194,共16页
防冲钻孔机器人是冲击地压矿井卸压的关键设备,其在复杂卸压巷道的精确地图构建和的稳定导航是实现钻孔作业智能化的基础和前提。在分析激光雷达点云畸变成因和同步定位与地图构建(SLAM)算法缺陷的基础上,设计了基于惯性测量单元(IMU)... 防冲钻孔机器人是冲击地压矿井卸压的关键设备,其在复杂卸压巷道的精确地图构建和的稳定导航是实现钻孔作业智能化的基础和前提。在分析激光雷达点云畸变成因和同步定位与地图构建(SLAM)算法缺陷的基础上,设计了基于惯性测量单元(IMU)连续时间轨迹的点云畸变矫正方法,建立了激光雷达和IMU的数据融合模型,提出了基于IMU-LiDAR紧耦合的防冲钻孔机器人定位建图方法。根据煤矿卸压巷道特点建立了密闭坡道模型,开展了建图效果仿真分析,结果表明,所提算法在定位精度、轨迹误差方面均优于现有常用算法。在此基础上,设计了基于改进人工势场法和快速扩展随机树的动态路径规划方法,建立了适用于防冲钻孔机器人的路径规划与导航融合方案,并设计了2种仿真运动场景,结果表明,所提路径规划方法在全局路径规划和动态路径规划的平均路径长度、平均运行时间、平均生成节点数等方面均具有较好的综合性能。为了进一步验证防冲钻孔机器人定位导航方法的实用性,在校内模拟巷道、地面实验基地和井下卸压巷道等场景下开展了多组对比实验,结果表明:将IMU数据与LiDAR数据紧耦合后,所提方法的定位建图精度明显提高,在特征退化场景中具有优越的定位建图性能,且规划路径的运算效率和路径代价方面均具有良好的表现,验证了所提定位导航方法在多种场景中的可行性和优越性。 展开更多
关键词 防冲钻孔机器人 同步定位与地图构建 惯性-雷达融合 定位导航 路径规划
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空间目标天基光学定位方法综述 被引量:1
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作者 李瑶 陈忻 饶鹏 《中国空间科学技术(中英文)》 CSCD 北大核心 2024年第2期1-15,共15页
近年来空间目标定位领域不断结合网络协同、多模融合等探测技术,发展迅速。其中,基于天基光学探测的定位方法以隐蔽性好、测量精度高的独特优势在民用和国防领域应用广泛。为了分析不同情景下适用于不同类型目标的定位方法,针对基于天... 近年来空间目标定位领域不断结合网络协同、多模融合等探测技术,发展迅速。其中,基于天基光学探测的定位方法以隐蔽性好、测量精度高的独特优势在民用和国防领域应用广泛。为了分析不同情景下适用于不同类型目标的定位方法,针对基于天基光学探测的空间小目标定位进行综述。首先介绍天基光学探测技术的发展、空间目标的分类和特点以及空间目标定位的概念。然后着重分析适用于空间“小、弱”目标的单星和多星定位方法,并对近年提出的异质传感器联合定位展开说明。最后,依据成像过程建立空间目标定位误差分析模型,分析定位精度的影响因素占比并根据现存问题做出总结和展望。 展开更多
关键词 天基光学探测 空间运动目标 小目标 定位方法 定位精度
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基于LIO-SAM建图和激光视觉融合定位的温室自主行走系统 被引量:4
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作者 孙国祥 黄银锋 +2 位作者 汪小旵 袁云鹏 陈光宇 《农业工程学报》 EI CAS CSCD 北大核心 2024年第3期227-239,共13页
为解决传统导航方案在温室内无法应对光照变化大、作物行间距窄、接收GPS信号差等问题,该研究提出了基于即时定位与地图构建技术的激光视觉融合式自主导航算法。该系统利用三维激光雷达VLP-16(Velodyne LiDAR,VLP-16)和惯性测量单元获... 为解决传统导航方案在温室内无法应对光照变化大、作物行间距窄、接收GPS信号差等问题,该研究提出了基于即时定位与地图构建技术的激光视觉融合式自主导航算法。该系统利用三维激光雷达VLP-16(Velodyne LiDAR,VLP-16)和惯性测量单元获取温室环境信息,采用基于紧耦合的雷达惯导定位建图(tightly-coupled lidar inertial odometry via smoothing and mapping,LIO-SAM)算法构建导航地图,基于轮式里程计和视觉里程计采用扩展卡尔曼滤波器算法实现局部定位,融合激光点云配准算法和自适应蒙特卡洛定位算法实现全局定位。同时,在自主行走系统应用A*算法规划全局路径和动态窗口算法规划局部路径,从而实现自主导航。试验结果表明,LIO-SAM算法构建的温室导航地图最大相对误差、最大绝对误差和均方根误差分别为9.9%、0.081和0.063 m,在温室内改进后的定位算法横向偏差小于0.020 m,纵向偏差小于0.090 m;当自主行走系统以0.15、0.30和0.50 m/s的速度运行时,横向偏差、纵向偏差和航向偏角的平均值分别小于0.120 m、0.10 m和8.5°,标准差分别小于0.070 m、0.140 m和6.6°。该导航方案满足自主行走系统在温室内高精度建图、定位和导航的需求,可为自主移动平台提供理论与技术支撑。 展开更多
关键词 温室 自主导航 视觉里程计 即时定位与地图构建 自适应蒙特卡洛定位 卡尔曼滤波
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新时代教育评价体系的价值定位:国际趋势与中国方案 被引量:4
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作者 辛涛 洪倩 李刚 《国家教育行政学院学报》 CSSCI 北大核心 2024年第2期13-21,共9页
教育评价体系的价值定位是指人们在开展评价过程中遵循的准则、理念或偏好,体现在各领域的评价样态之中。近十年来,发达国家在教育评价改革中存在服务发展、精准刻画、多元参与这三类主要价值定位,我国新时代教育评价改革亦对这些价值... 教育评价体系的价值定位是指人们在开展评价过程中遵循的准则、理念或偏好,体现在各领域的评价样态之中。近十年来,发达国家在教育评价改革中存在服务发展、精准刻画、多元参与这三类主要价值定位,我国新时代教育评价改革亦对这些价值导向有所探索。进一步构建新时代具有中国特色的教育评价体系的价值体系,需要构建以学生全面发展为核心的教育评价价值体系,以立德树人为根本遵循统合“服务发展”的价值定位,以开放的态度对待“精准刻画”的技术倡议并加强研究澄清,加强“多元参与导向”的制度化建设。 展开更多
关键词 教育评价 价值定位 服务发展 精确刻画 多元参与
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小麦倒春寒响应基因TaJAZ6的克隆、表达模式及亚细胞定位分析 被引量:1
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作者 张自阳 周谦 +4 位作者 王依 王志伟 朱启迪 茹振钢 刘明久 《华北农学报》 CSCD 北大核心 2024年第1期27-36,共10页
JAZ蛋白在植物生长发育和胁迫信号通路中具有关键作用。为探究JAZ蛋白在小麦倒春寒中的调控机制,从小麦幼穗中克隆了TaJAZ6基因,并对其分子特征、表达特性与亚细胞定位进行分析。结果表明,该基因CDS序列全长为549 bp,编码178个氨基酸,... JAZ蛋白在植物生长发育和胁迫信号通路中具有关键作用。为探究JAZ蛋白在小麦倒春寒中的调控机制,从小麦幼穗中克隆了TaJAZ6基因,并对其分子特征、表达特性与亚细胞定位进行分析。结果表明,该基因CDS序列全长为549 bp,编码178个氨基酸,预测编码蛋白质的分子质量为18.376 ku,理论等电点为9.37,不稳定系数为62.44,属于不稳定蛋白。该基因编码蛋白质具有1个TIFY结构域和1个CCT_2结构域。系统进化树分析发现,该蛋白质与野生二粒小麦和乌拉尔图小麦TIFY 11b蛋白亲缘关系最近。TaJAZ6基因启动子区除含有CAAT-box、TATA-box等基础作用元件外,还含有激素类响应元件、光响应元件、低温响应元件、防御和应激反应元件等。实时荧光定量PCR分析发现,TaJAZ6基因在根、茎、叶和幼穗中均有表达,根系中表达量最高。TaJAZ6基因还受低温和茉莉酸甲酯(MeJA)的诱导表达,低温胁迫下,TaJAZ6在矮抗58(耐倒春寒)和郑麦366(倒春寒敏感)根、茎和叶中表达趋势相同,均显著升高;喷施300,350μmol/L的MeJA之后再低温处理TaJAZ6在2个小麦品种中表达量均显著下降。TaJAZ6在低温胁迫后的幼穗中表达量出现相反的趋势,在矮抗58幼穗中表达量显著下降,在郑麦366幼穗中则显著上升,推测该基因可能负调控了小麦倒春寒胁迫防御反应。通过喷施MeJA显著降低了低温胁迫下2个小麦品种幼穗中TaJAZ6基因的相对表达量,同时提高了小麦的结实粒数。亚细胞定位试验显示,TaJAZ6蛋白定位于细胞核中。以上研究结果表明,TaJAZ6可能在小麦响应倒春寒胁迫过程中发挥重要作用。 展开更多
关键词 小麦 TaJAZ6基因 表达分析 低温胁迫 亚细胞定位
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基于高度角随机模型的GNSS外辐射源雷达定位算法 被引量:1
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作者 杨东凯 谭传瑞 +1 位作者 王峰 李唐 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第4期1373-1381,共9页
针对GNSS外辐射源雷达定位时不同卫星对定位的误差贡献不同的问题,提出基于高度角随机模型的定位算法,理论分析目标位置估计量的克拉美罗界和统计特性,并计算卫星位置误差和地面站位置误差对定位误差的影响。仿真结果表明:所提出算法对... 针对GNSS外辐射源雷达定位时不同卫星对定位的误差贡献不同的问题,提出基于高度角随机模型的定位算法,理论分析目标位置估计量的克拉美罗界和统计特性,并计算卫星位置误差和地面站位置误差对定位误差的影响。仿真结果表明:所提出算法对不同GNSS卫星的直射、反射路径的伪距差测量值误差进行了合理分配,定位性能达到了克拉美罗界,且不会因为选星方案的改变而大幅恶化。对地面站位置误差和卫星位置误差的分析表明:地面站位置的标准差小于10 cm、卫星位置的标准差小于1 km时对定位总误差的贡献可以忽略不计。 展开更多
关键词 高度角随机模型 GNSS 定位 克拉美罗界
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