The rising of aging and the declining of birth rates have forced the public to focus on the youth’s view on marriage.Based on critical discourse analysis and combined with Fairclough’s three-dimensional discourse an...The rising of aging and the declining of birth rates have forced the public to focus on the youth’s view on marriage.Based on critical discourse analysis and combined with Fairclough’s three-dimensional discourse analysis model,this paper builds a“Chinese media News Report Corpus on the topic of‘marriage’”whose news are collected from China Daily.It is found that the discourses are neutral and objective with regard to the advantages and disadvantages of marriage,but in general,it is still a traditional view of marriage that is inevitable and closely related to fertility.Although this is controlled by the policies and the social reasons including declining fertility rate,it deviates from the current view of the youth towards marriage,resulting in many serious consequences such as young people’s rejection.In addition,this research found that male and female have great differences in their views on marriage,and men’s resistance to marriage is far greater than that of women,which is departure from the public’s cognition.The reasons behind this need to be explored in order to solve the marriage and love problems of young people in today’s era and realize the healthy development of young marriage.展开更多
Purpose:Robot-assisted technology is a forefront of surgical innovation that improves the accuracy of total knee arthroplasty (TKA).But whether the accuracy of surgery can improve the clinical efficacy still needs fur...Purpose:Robot-assisted technology is a forefront of surgical innovation that improves the accuracy of total knee arthroplasty (TKA).But whether the accuracy of surgery can improve the clinical efficacy still needs further research.The purpose of this study is to perform three-dimensional (3D) analysis in the early postoperative period of patients who received robot-assisted total knee arthroplasty (RATKA),and to study the trend of changes in gait parameters after RATKA and the correlation with the early clinical efficacy.Methods:Patients who received RATKA in the Center of Joint Surgery,the First Hospital Affiliated to Army Military Medical University from October 2020 to January 2021 were included.The imaging parameters,i.e.,hip-knee-ankle angle,lateral distal femoral angle,medial proximal tibial angle,posterior condylar angle were measured 3 months post-TKA.The 3D gait analysis and clinical efficacy by Western Ontario Mac Master University Index (WOMAC) score were performed pre-TKA,3 and 6 months post-TKA.The differences in spatiotemporal parameters of gait,kinetic parameters,and kinematic parameters of the operated limb and the contralateral limb were compared.The correlation between gait parameters and WOMAC scores was analyzed.Paired samplet-test and Wilcoxon rank-sum test were used to analyze the difference between groups,and Spearman correlation coefficient was used to analyze the correlation.Results:There were 31 patients included in this study,and the imaging indexes showed that all of them returned to normal post-TKA.The WOMAC score at 3 months post-TKA was significantly lower than that pre-TKA,and there was no significant difference between at 3 and 6 months.The 3D gait analysis results showed that the double support time of the operated limb reduced at 3 and 6 months (allp < 0.05),the maximum extension and maximum external rotation of the knee joint increased at stance phase,and the maximum flexion angle,the range of motion and the maximum external rotation increased at swing phase.Compared with the preoperative data,there were significant improvements (allp < 0.05).Compared with the contralateral knee joint,the maximum external rotation of the knee joint at swing phase was smaller than that of the contralateral side,and the maximum flexion and extension moment was greater than that of the contralateral knee.The maximum external rotation moment of the joint was greater than that of the contralateral knee joint (p < 0.05).There was a negative correlation between the single support time pre-TKA and the WOMAC score at 3 months (p = 0.017),and the single support time at 3 months was negatively correlated with the WOMAC score at 6 months (p = 0.043).The cadence at 6 months was negatively correlated with the WOMAC score at 6 months (p = 0.031).The maximum knee extension at stance phase at 6 months was negatively correlated with the WOMAC score at 6 month (p = 0.048).The maximum external rotation at stance phase at 6 months was negatively correlated with the WOMAC score at 6 months (p = 0.024).Conclusion:The 3D gait analysis of RATKA patients is more sensitive than WOMAC score in evaluating the clinical efficacy.Trend of changes in gait parameters shows that the knee joint support,flexion and extension function,range of motion,external rotation and varus deformity moment of the patient were significantly improved at 3 months after surgery,and continued to 6 months after surgery.Compared with the contralateral knee,the gait parameters of the operated limb still has significant gaps in functionality,such as the external rotation and flexion and extension.The single support time,cadence,knee extension,and knee external rotation of the operated limb have a greater correlation with the postoperative WOMAC score.Postoperative rehabilitation exercises should be emphasized,which is of great value for improving the early efficacy of RATKA.展开更多
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
Purpose: This study focused on maintaining and improving the walking function of late-stage older individuals while longitudinally tracking the effects of regular exercise programs in a day-care service specialized fo...Purpose: This study focused on maintaining and improving the walking function of late-stage older individuals while longitudinally tracking the effects of regular exercise programs in a day-care service specialized for preventive care over 5 years, using detailed gait function measurements with an accelerometer-based system. Methods: Seventy individuals (17 male and 53 female) of a daycare service in Tokyo participated in a weekly exercise program, meeting 1 - 2 times. The average age of the participants at the start of the program was 81.4 years. Gait function, including gait speed, stride length, root mean square (RMS) of acceleration, gait cycle time and its standard deviation, and left-right difference in stance time, was evaluated every 6 months. Results: Gait speed and stride length improved considerably within six months of starting the exercise program, confirming an initial improvement in gait function. This suggests that regular exercise programs can maintain or improve gait function even age groups that predictably have a gradual decline in gait ability due to enhanced age. In the long term, many indicators tended to approach baseline values. However, the exercise program seemingly counteracts age-related changes in gait function and maintains a certain level of function. Conclusions: While a decline in gait ability with aging is inevitable, establishing appropriate exercise habits in late-stage older individuals may contribute to long-term maintenance of gait function.展开更多
Purpose: This study verified the effects of transcutaneous electrical nerve stimulation (TENS), which can be worn during walking and exercise, in elderly individuals with late-stage knee pain who exercise regularly. M...Purpose: This study verified the effects of transcutaneous electrical nerve stimulation (TENS), which can be worn during walking and exercise, in elderly individuals with late-stage knee pain who exercise regularly. Methods: Thirty-two late-stage elderly individuals were evaluated for knee pain during rest, walking, and program exercises, with and without TENS. Gait analysis was performed using an IoT-based gait analysis device to examine the effects of TENS-induced analgesia on gait. Results: TENS significantly reduced knee pain during rest, walking, and programmed exercises, with the greatest analgesic effect observed during walking. The greater the knee pain without TENS, the more significant the analgesic effect of TENS. A comparison of gait parameters revealed a significant difference only in the gait cycle time, with a trend towards faster walking with TENS;however, the effect was limited. Conclusion: TENS effectively relieves knee pain in late-stage elderly individuals and can be safely applied during exercise. Pain management using TENS provides important insights into the implementation of exercise therapy in this age group.展开更多
Based on the upper bound of limit analysis, the plane-strain analysis of the slopes reinforced with a row of piles to the 3D case was extended. A 3D rotational failure mechanism was adopted to yield the upper bound of...Based on the upper bound of limit analysis, the plane-strain analysis of the slopes reinforced with a row of piles to the 3D case was extended. A 3D rotational failure mechanism was adopted to yield the upper bound of the factor of safety. Parametric studies were carried out to explore the end effects of the slope failures and the effects of the pile location and diameter on the safety of the reinforced slopes. The results demonstrate that the end effects nearly have no effects on the most suitable location of the installed piles but have significant influence on the safety of the slopes. For a slope constrained to a narrow width, the slope becomes more stable owing to the contribution of the end effects. When the slope is reinforced with a row of piles in small space between piles, the effects of group piles are significant for evaluating the safety of slopes. The presented method is more appropriate for assessing the stability of slopes reinforced with piles and can be also utilized in the design of plies stabilizing the unstable slopes.展开更多
A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-indu...A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-induced volume loss effects.The numerical model was verified based on the results of a centrifuge test and a set of parametric studies was implemented based on this model.There is good agreement between the trend of the results of the centrifuge test and the present model.The results of parametric studies show that the tunnelling-induced pile internal force and deformation depend mainly on the pile?tunnel distance,the pile length to tunnel depth ratio and the volume loss.Two different zones are separated by a 45° line projected from the tunnel springline.Within the zone of influence,the pile is subjected to tensile force and large settlement;whereas outside the zone of influence,dragload and small settlement are induced.It is also established that the impact of tunnelling on a pile group is substantially smaller as compared with a single pile in the same location with the rear pile in a group,demonstrating a positive pile group effect.展开更多
In the last decade, three dimensional discontin- uous deformation analyses (3D DDA) has attracted more and more attention of researchers and geotechnical engineers worldwide. The original DDA formulation utilizes a ...In the last decade, three dimensional discontin- uous deformation analyses (3D DDA) has attracted more and more attention of researchers and geotechnical engineers worldwide. The original DDA formulation utilizes a linear displacement function to describe the block movement and deformation, which would cause block expansion under rigid body rotation and thus limit its capability to model block de- formation. In this paper, 3D DDA is coupled with tetrahe- dron finite elements to tackle these two problems. Tetrahe- dron is the simplest in the 3D domain and makes it easy to implement automatic discretization, even for complex topol- ogy shape. Furthermore, element faces will remain planar and element edges will remain straight after deformation for tetrahedron finite elements and polyhedral contact detection schemes can be used directly. The matrices of equilibrium equations for this coupled method are given in detail and an effective contact searching algorithm is suggested. Valida- tion is conducted by comparing the results of the proposed coupled method with that of physical model tests using one of the most common failure modes, i.e., wedge failure. Most of the failure modes predicted by the coupled method agree with the physical model results except for 4 cases out of the total 65 cases. Finally, a complex rockslide example demon- strates the robustness and versatility of the coupled method.展开更多
A three-dimensional analysis of a simply-supported functionally graded rectangular plate with an arbitrary distribution of material properties is made using a simple and effective method based on the Haar wavelet. Wit...A three-dimensional analysis of a simply-supported functionally graded rectangular plate with an arbitrary distribution of material properties is made using a simple and effective method based on the Haar wavelet. With good features in treating singularities, Haar series solution converges rapidly for arbitrary distributions, especially for the case where the material properties change rapidly in some regions. Through numerical examples the influences of the ratio of material constants on the top and bottom surfaces and different material gradient distributions on the structural response of the plate to mechanical stimuli are studied.展开更多
A three-dimensional analysis model based on the finite element method (FEM) is developed, which can derive the evolution and distribution characteristics of heat flux deposited on the divertor plate from the surface...A three-dimensional analysis model based on the finite element method (FEM) is developed, which can derive the evolution and distribution characteristics of heat flux deposited on the divertor plate from the surface temperature measured by infrared thermography diagnostics. The numerical simulations of surface heating due to localized power bursts and the power deposition calculations demonstrate that this analysis can provide accurate results and useful information about localized hot spots compared with the normal one- and two-dimensional calculations. In this paper, the details of this three- dimensional analysis are presented, and some results in ohmic heating and electron cyclotron resonant heating (ECRH) discharge on HL-2A are given.展开更多
In the framework of upper bound theorem of limit analysis, the progressive collapse of shallow rectangular tunnels with double-layer rock mass has been theoretically analyzed based on the three-dimensional (3D) veloci...In the framework of upper bound theorem of limit analysis, the progressive collapse of shallow rectangular tunnels with double-layer rock mass has been theoretically analyzed based on the three-dimensional (3D) velocity discontinuity surfaces. According to the virtual work principle, the difference theorem and the variation method, the collapse surface of double-layer rock mass is determined based on the Hoek-Brown failure criterion. The formula can be degenerated to a single-layer rock collapsing problem when the rock mass is homogeneous. To estimate the validity of the result, the numerical simulation software PLAXIS 3D is used to simulate the collapse of shallow tunnels with double-layer rock mass, and the comparative analysis shows that numerical results are in good agreement with upper-bound solutions. According to the results of parametric analysis, the potential range of collapse of a double-layer rock mass above a shallow cavity decreases with a decrease in A1/A2,σci1/σci2 and σtm1/σtm2 and an increase in B1/B2,γ1/γ2. The range will decrease with a decrease in support pressure q and increase with a decrease in surface overload σs. Therefore, reinforced supporting is beneficial to improve the stability of the cavity during actual construction.展开更多
Using bathymetry and altimetric gravity anomalies, a 1°×9 1° lithospheric effective elastic thickness(Te) model over the Louisville Ridge and its adjacent regions is calculated using the moving window...Using bathymetry and altimetric gravity anomalies, a 1°×9 1° lithospheric effective elastic thickness(Te) model over the Louisville Ridge and its adjacent regions is calculated using the moving window admittance technique. For comparison, three bathymetry models are used: general bathymetric charts of the oceans, SIO V15.1,and BAT_VGG. The results show that BAT_VGG is more suitable for calculating T e than the other two models. T e along the Louisville Ridge was re-evaluated. The southeast of the ridge has a medium Te of 10–20 km, while Te increases dramatically seaward of the Tonga-Kermadec trench as a result of the collision of the Pacific and IndoAustralian plates.展开更多
This paper proposes a based on 3D-VLE (three-dimensional nonlinear viscoelastic theory) three-parameters viscoelastic model for studying the time-dependent behaviour of concrete filled steel tube (CFT) columns. Th...This paper proposes a based on 3D-VLE (three-dimensional nonlinear viscoelastic theory) three-parameters viscoelastic model for studying the time-dependent behaviour of concrete filled steel tube (CFT) columns. The method of 3D-VLE was developed to analyze the effects of concrete creep behavior on CFT structures. After the evaluation of the parameters in the proposed creep model, experimental measurements of two prestressed reinforced concrete beams were used to investigate the creep phenomenon of three CFT columns under long-term axial and eccentric load was investigated. The experimentally obtained time-dependent creep behaviour accorded well with the cu~'es obtained from the proposed method. Many factors (such as ratio of long-term load to strength, slenderness ratio, steel ratio, and eccentricity ratio) were considered to obtain the regularity of influence of concrete creep on CFT structures. The analytical results can be consulted in the engineering practice and design.展开更多
Based on the working of Lighthill and Hunt et al., in the present paper the author has established the topological rules adapting to analysing the skin-friction lines and the section streamlines in cascades. These rul...Based on the working of Lighthill and Hunt et al., in the present paper the author has established the topological rules adapting to analysing the skin-friction lines and the section streamlines in cascades. These rules are (1) for a rotor cascade without shroud band, the total number of nodal points equals that the saddle points on the skin-friction line vector fields in eachpitch range; (2) for an annular or straight cascade with no-clearances at blade ends, the total number of saddle points is two more than that of nodal points on the skin-friction line fields in a pitch; (3) the total number of saddles in the secondary flow fields on cross-sections in cascade is one less than that of nodes; (4) in the section streamline vector fields on a meridian surface penetrating a flow passage, and on leading and trailing edge sections, the total number of nodes is equal to that of saddles; (5) on the streamline vector fields of a blade-to-blade surface, the total number of nodes is one less than that of saddles.展开更多
This paper demonstrates the importance of three-dimensional(3-D)piezoelectric coupling in the electromechanical behavior of piezoelectric devices using three-dimensional finite element analyses based on weak and stron...This paper demonstrates the importance of three-dimensional(3-D)piezoelectric coupling in the electromechanical behavior of piezoelectric devices using three-dimensional finite element analyses based on weak and strong coupling models for a thin cantilevered piezoelectric bimorph actuator.It is found that there is a significant difference between the strong and weak coupling solutions given by coupling direct and inverse piezoelectric effects(i.e.,piezoelectric coupling effect).In addition,there is significant longitudinal bending caused by the constraint of the inverse piezoelectric effect in the width direction at the fixed end(i.e.,3-D effect).Hence,modeling of these effects or 3-D piezoelectric coupling modeling is an electromechanical basis for the piezoelectric devices,which contributes to the accurate prediction of their behavior.展开更多
A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analy...A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analysis theory.The soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield criterion.Block analysis technique is employed to investigate the collapse of 3DRT.The model is divided into five different block types and added up to ten rigid blocks.According to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search proceeding.The results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square trapdoors.The critical stability ratios can be used in the design of underground excavation and support force.展开更多
The intricate anatomy of the corpus cavernosum in both the flaccid and tumescent state has not been fully elucidated. We report our experience using a three-dimensional (3D) scanner to reconstruct cadaveric casts an...The intricate anatomy of the corpus cavernosum in both the flaccid and tumescent state has not been fully elucidated. We report our experience using a three-dimensional (3D) scanner to reconstruct cadaveric casts and compare them with 3D images of two prototypes of penile prosthesis. Two different models of the Titan Coloplast inflatable penile prosthesis were analyzed using a 3D scanner. The first was the standard model and the second was a newer model with a rounder silicone tip. Two cadaveric phalluses were harvested using Smooth-Cast 300Q polyurethane molding. The molds were excised and scanned along side the penile prosthesis. 3D scans were completed and analyzed using Leios Mesh software, and GOM Inspect software. The 3D scans demonstrated the mean human corporal radii 2 mm from the distal tip to be 36.51 mm (36.01-37.0 mm), which is an obtuse angle. The standard Titan penile prosthesis spherical radius at the same level was 202.52 mm, while the new silicone tip prosthesis had a radius of 139.33 mm. 3D mapping further demonstrated the trajectory of the cavernosa appeared curvilinear and the distal ends appeared blunt. The use of cadaveric cavernosal molds in combination with the 3D scanner allowed us to accurately image the corpus cavernosum for the first time. Our findings suggest that anatomically accurate corporal tips appear to be relatively blunt and that the new Titan silicone tip penile prosthesis more closely resembles the human corporal tip.展开更多
With an application of topological analysis,in this paper the skin-friction line patterns on compressor and turbine cascade surfaces are depicted and the streamline patterns of the secondary flow fields in the cross-s...With an application of topological analysis,in this paper the skin-friction line patterns on compressor and turbine cascade surfaces are depicted and the streamline patterns of the secondary flow fields in the cross-section of a curved pipe and a turbine cascade are drawn under given conditions.In addition the structures of vortices within three-dimensional viscous flow fields in cascades are analysed.展开更多
The paper applies a mathematical model[1] for specular reflection to plain-knitted fabrics by using a three-dimensional analysis. Computer simulation of goniophotometric curves is generated based oa the model. Correct...The paper applies a mathematical model[1] for specular reflection to plain-knitted fabrics by using a three-dimensional analysis. Computer simulation of goniophotometric curves is generated based oa the model. Correction factors are introduced by taking into consideration of geometry of the instrument used. Comparison between the simulated and the measured curves of a straight monofilament yarn with various orientation angles is carried out and reasonable agreement has been obtained.展开更多
In previous studies,Lagrangian analyses were used to assess large-scale ocean circulation,and the Lagrangian coherent structure could also reveal the evolution of the two-dimensional structure of the mesoscale eddies....In previous studies,Lagrangian analyses were used to assess large-scale ocean circulation,and the Lagrangian coherent structure could also reveal the evolution of the two-dimensional structure of the mesoscale eddies.However,few studies have demonstrated the three-dimensional structure of the mesoscale eddies via Lagrangian analysis.Compared with previous studies,which investigated the eddy structure via a Eulerian view,we used a Lagrangian view to provide a different perspective to study the eddy structure.An idealized cyclonic mesoscale eddy is built up over a seamount,and it presents downwelling inside the eddy and upwelling alongside the eddy formed within a closed circulation system.This structure is difficult to display via a Eulerian analysis.However,the trajectories of particles can well demonstrate the full cycle:the fluid sank and rotated inside the eddies,converged to the upwelling zone of the bottom layer and returned to the surface through upwelling.We also applied a Lagrangian analysis to a realistic simulation.As a significant phenomenon in the South China Sea,the dipole structure of the anticyclonic eddy(AE)/cyclonic eddy(CE)pair off of central Vietnam has been well studied but mainly at the sea surface.With a Lagrangian analysis,we illustrate the three-dimensional structure of the eddy pair:the fluid sank(rose)and rotated inside the AE(CE).More importantly,the trajectories of the particles suggested that there was no fluid exchange between the two eddies since the strong boundary jet separates them from each other.All the conclusions above have been verified and are supported by the computational error estimate.With a selected time step and integral period,the computational errors always present small values,although they increase with strong divergent and vertical diffusive flow.展开更多
文摘The rising of aging and the declining of birth rates have forced the public to focus on the youth’s view on marriage.Based on critical discourse analysis and combined with Fairclough’s three-dimensional discourse analysis model,this paper builds a“Chinese media News Report Corpus on the topic of‘marriage’”whose news are collected from China Daily.It is found that the discourses are neutral and objective with regard to the advantages and disadvantages of marriage,but in general,it is still a traditional view of marriage that is inevitable and closely related to fertility.Although this is controlled by the policies and the social reasons including declining fertility rate,it deviates from the current view of the youth towards marriage,resulting in many serious consequences such as young people’s rejection.In addition,this research found that male and female have great differences in their views on marriage,and men’s resistance to marriage is far greater than that of women,which is departure from the public’s cognition.The reasons behind this need to be explored in order to solve the marriage and love problems of young people in today’s era and realize the healthy development of young marriage.
基金National Key R&D Program of China(2017YFC0110705)。
文摘Purpose:Robot-assisted technology is a forefront of surgical innovation that improves the accuracy of total knee arthroplasty (TKA).But whether the accuracy of surgery can improve the clinical efficacy still needs further research.The purpose of this study is to perform three-dimensional (3D) analysis in the early postoperative period of patients who received robot-assisted total knee arthroplasty (RATKA),and to study the trend of changes in gait parameters after RATKA and the correlation with the early clinical efficacy.Methods:Patients who received RATKA in the Center of Joint Surgery,the First Hospital Affiliated to Army Military Medical University from October 2020 to January 2021 were included.The imaging parameters,i.e.,hip-knee-ankle angle,lateral distal femoral angle,medial proximal tibial angle,posterior condylar angle were measured 3 months post-TKA.The 3D gait analysis and clinical efficacy by Western Ontario Mac Master University Index (WOMAC) score were performed pre-TKA,3 and 6 months post-TKA.The differences in spatiotemporal parameters of gait,kinetic parameters,and kinematic parameters of the operated limb and the contralateral limb were compared.The correlation between gait parameters and WOMAC scores was analyzed.Paired samplet-test and Wilcoxon rank-sum test were used to analyze the difference between groups,and Spearman correlation coefficient was used to analyze the correlation.Results:There were 31 patients included in this study,and the imaging indexes showed that all of them returned to normal post-TKA.The WOMAC score at 3 months post-TKA was significantly lower than that pre-TKA,and there was no significant difference between at 3 and 6 months.The 3D gait analysis results showed that the double support time of the operated limb reduced at 3 and 6 months (allp < 0.05),the maximum extension and maximum external rotation of the knee joint increased at stance phase,and the maximum flexion angle,the range of motion and the maximum external rotation increased at swing phase.Compared with the preoperative data,there were significant improvements (allp < 0.05).Compared with the contralateral knee joint,the maximum external rotation of the knee joint at swing phase was smaller than that of the contralateral side,and the maximum flexion and extension moment was greater than that of the contralateral knee.The maximum external rotation moment of the joint was greater than that of the contralateral knee joint (p < 0.05).There was a negative correlation between the single support time pre-TKA and the WOMAC score at 3 months (p = 0.017),and the single support time at 3 months was negatively correlated with the WOMAC score at 6 months (p = 0.043).The cadence at 6 months was negatively correlated with the WOMAC score at 6 months (p = 0.031).The maximum knee extension at stance phase at 6 months was negatively correlated with the WOMAC score at 6 month (p = 0.048).The maximum external rotation at stance phase at 6 months was negatively correlated with the WOMAC score at 6 months (p = 0.024).Conclusion:The 3D gait analysis of RATKA patients is more sensitive than WOMAC score in evaluating the clinical efficacy.Trend of changes in gait parameters shows that the knee joint support,flexion and extension function,range of motion,external rotation and varus deformity moment of the patient were significantly improved at 3 months after surgery,and continued to 6 months after surgery.Compared with the contralateral knee,the gait parameters of the operated limb still has significant gaps in functionality,such as the external rotation and flexion and extension.The single support time,cadence,knee extension,and knee external rotation of the operated limb have a greater correlation with the postoperative WOMAC score.Postoperative rehabilitation exercises should be emphasized,which is of great value for improving the early efficacy of RATKA.
文摘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.
文摘Purpose: This study focused on maintaining and improving the walking function of late-stage older individuals while longitudinally tracking the effects of regular exercise programs in a day-care service specialized for preventive care over 5 years, using detailed gait function measurements with an accelerometer-based system. Methods: Seventy individuals (17 male and 53 female) of a daycare service in Tokyo participated in a weekly exercise program, meeting 1 - 2 times. The average age of the participants at the start of the program was 81.4 years. Gait function, including gait speed, stride length, root mean square (RMS) of acceleration, gait cycle time and its standard deviation, and left-right difference in stance time, was evaluated every 6 months. Results: Gait speed and stride length improved considerably within six months of starting the exercise program, confirming an initial improvement in gait function. This suggests that regular exercise programs can maintain or improve gait function even age groups that predictably have a gradual decline in gait ability due to enhanced age. In the long term, many indicators tended to approach baseline values. However, the exercise program seemingly counteracts age-related changes in gait function and maintains a certain level of function. Conclusions: While a decline in gait ability with aging is inevitable, establishing appropriate exercise habits in late-stage older individuals may contribute to long-term maintenance of gait function.
文摘Purpose: This study verified the effects of transcutaneous electrical nerve stimulation (TENS), which can be worn during walking and exercise, in elderly individuals with late-stage knee pain who exercise regularly. Methods: Thirty-two late-stage elderly individuals were evaluated for knee pain during rest, walking, and program exercises, with and without TENS. Gait analysis was performed using an IoT-based gait analysis device to examine the effects of TENS-induced analgesia on gait. Results: TENS significantly reduced knee pain during rest, walking, and programmed exercises, with the greatest analgesic effect observed during walking. The greater the knee pain without TENS, the more significant the analgesic effect of TENS. A comparison of gait parameters revealed a significant difference only in the gait cycle time, with a trend towards faster walking with TENS;however, the effect was limited. Conclusion: TENS effectively relieves knee pain in late-stage elderly individuals and can be safely applied during exercise. Pain management using TENS provides important insights into the implementation of exercise therapy in this age group.
基金Projects(51278382,51479050)supported by the National Natural Science Foundation of ChinaProject(2015CB057901)supported by the National Key Basic Research Program of China+3 种基金Project(201501035-03)supported by the Public Service Sector R&D Project of Ministry of Water Resource of ChinaProject(2014B06814)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(B13024)supported by the"111"ProjectProject(YK913004)supported by the Open Foundation of Key Laboratory of Failure Mechanism and Safety Control Techniques of Earthrock Dam of the Ministry of Water Resources,China
文摘Based on the upper bound of limit analysis, the plane-strain analysis of the slopes reinforced with a row of piles to the 3D case was extended. A 3D rotational failure mechanism was adopted to yield the upper bound of the factor of safety. Parametric studies were carried out to explore the end effects of the slope failures and the effects of the pile location and diameter on the safety of the reinforced slopes. The results demonstrate that the end effects nearly have no effects on the most suitable location of the installed piles but have significant influence on the safety of the slopes. For a slope constrained to a narrow width, the slope becomes more stable owing to the contribution of the end effects. When the slope is reinforced with a row of piles in small space between piles, the effects of group piles are significant for evaluating the safety of slopes. The presented method is more appropriate for assessing the stability of slopes reinforced with piles and can be also utilized in the design of plies stabilizing the unstable slopes.
文摘A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-induced volume loss effects.The numerical model was verified based on the results of a centrifuge test and a set of parametric studies was implemented based on this model.There is good agreement between the trend of the results of the centrifuge test and the present model.The results of parametric studies show that the tunnelling-induced pile internal force and deformation depend mainly on the pile?tunnel distance,the pile length to tunnel depth ratio and the volume loss.Two different zones are separated by a 45° line projected from the tunnel springline.Within the zone of influence,the pile is subjected to tensile force and large settlement;whereas outside the zone of influence,dragload and small settlement are induced.It is also established that the impact of tunnelling on a pile group is substantially smaller as compared with a single pile in the same location with the rear pile in a group,demonstrating a positive pile group effect.
基金supported by the Key Project of Chinese National Programs for Fundamental Research and Development(2010CB731502)the National Natural Science Foundation of China(50978745)
文摘In the last decade, three dimensional discontin- uous deformation analyses (3D DDA) has attracted more and more attention of researchers and geotechnical engineers worldwide. The original DDA formulation utilizes a linear displacement function to describe the block movement and deformation, which would cause block expansion under rigid body rotation and thus limit its capability to model block de- formation. In this paper, 3D DDA is coupled with tetrahe- dron finite elements to tackle these two problems. Tetrahe- dron is the simplest in the 3D domain and makes it easy to implement automatic discretization, even for complex topol- ogy shape. Furthermore, element faces will remain planar and element edges will remain straight after deformation for tetrahedron finite elements and polyhedral contact detection schemes can be used directly. The matrices of equilibrium equations for this coupled method are given in detail and an effective contact searching algorithm is suggested. Valida- tion is conducted by comparing the results of the proposed coupled method with that of physical model tests using one of the most common failure modes, i.e., wedge failure. Most of the failure modes predicted by the coupled method agree with the physical model results except for 4 cases out of the total 65 cases. Finally, a complex rockslide example demon- strates the robustness and versatility of the coupled method.
基金Project supported by the National Natural Sciences Foundation of China(No.10432030).
文摘A three-dimensional analysis of a simply-supported functionally graded rectangular plate with an arbitrary distribution of material properties is made using a simple and effective method based on the Haar wavelet. With good features in treating singularities, Haar series solution converges rapidly for arbitrary distributions, especially for the case where the material properties change rapidly in some regions. Through numerical examples the influences of the ratio of material constants on the top and bottom surfaces and different material gradient distributions on the structural response of the plate to mechanical stimuli are studied.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10805016)the National Magnetic Confinement Fusion Science Program,China (Grant No. 2009GB104008).
文摘A three-dimensional analysis model based on the finite element method (FEM) is developed, which can derive the evolution and distribution characteristics of heat flux deposited on the divertor plate from the surface temperature measured by infrared thermography diagnostics. The numerical simulations of surface heating due to localized power bursts and the power deposition calculations demonstrate that this analysis can provide accurate results and useful information about localized hot spots compared with the normal one- and two-dimensional calculations. In this paper, the details of this three- dimensional analysis are presented, and some results in ohmic heating and electron cyclotron resonant heating (ECRH) discharge on HL-2A are given.
基金Projects(51478477,51878074)supported by the National Natural Science Foundation of ChinaProject(2017-123-033)supported by the Guizhou Provincial Department of Transportation Foundation,ChinaProjects(2018zzts663,2018zzts656)supported by the Fundamental Research Funds for the Central Universities,China
文摘In the framework of upper bound theorem of limit analysis, the progressive collapse of shallow rectangular tunnels with double-layer rock mass has been theoretically analyzed based on the three-dimensional (3D) velocity discontinuity surfaces. According to the virtual work principle, the difference theorem and the variation method, the collapse surface of double-layer rock mass is determined based on the Hoek-Brown failure criterion. The formula can be degenerated to a single-layer rock collapsing problem when the rock mass is homogeneous. To estimate the validity of the result, the numerical simulation software PLAXIS 3D is used to simulate the collapse of shallow tunnels with double-layer rock mass, and the comparative analysis shows that numerical results are in good agreement with upper-bound solutions. According to the results of parametric analysis, the potential range of collapse of a double-layer rock mass above a shallow cavity decreases with a decrease in A1/A2,σci1/σci2 and σtm1/σtm2 and an increase in B1/B2,γ1/γ2. The range will decrease with a decrease in support pressure q and increase with a decrease in surface overload σs. Therefore, reinforced supporting is beneficial to improve the stability of the cavity during actual construction.
基金supported financially by the Key Foundation of the Institute of Seismology,China Earthquake Administration (No. IS201506205)the National Natural Science Foundation of China (Nos. 41504017, 41204019, 41304003)
文摘Using bathymetry and altimetric gravity anomalies, a 1°×9 1° lithospheric effective elastic thickness(Te) model over the Louisville Ridge and its adjacent regions is calculated using the moving window admittance technique. For comparison, three bathymetry models are used: general bathymetric charts of the oceans, SIO V15.1,and BAT_VGG. The results show that BAT_VGG is more suitable for calculating T e than the other two models. T e along the Louisville Ridge was re-evaluated. The southeast of the ridge has a medium Te of 10–20 km, while Te increases dramatically seaward of the Tonga-Kermadec trench as a result of the collision of the Pacific and IndoAustralian plates.
文摘This paper proposes a based on 3D-VLE (three-dimensional nonlinear viscoelastic theory) three-parameters viscoelastic model for studying the time-dependent behaviour of concrete filled steel tube (CFT) columns. The method of 3D-VLE was developed to analyze the effects of concrete creep behavior on CFT structures. After the evaluation of the parameters in the proposed creep model, experimental measurements of two prestressed reinforced concrete beams were used to investigate the creep phenomenon of three CFT columns under long-term axial and eccentric load was investigated. The experimentally obtained time-dependent creep behaviour accorded well with the cu~'es obtained from the proposed method. Many factors (such as ratio of long-term load to strength, slenderness ratio, steel ratio, and eccentricity ratio) were considered to obtain the regularity of influence of concrete creep on CFT structures. The analytical results can be consulted in the engineering practice and design.
文摘Based on the working of Lighthill and Hunt et al., in the present paper the author has established the topological rules adapting to analysing the skin-friction lines and the section streamlines in cascades. These rules are (1) for a rotor cascade without shroud band, the total number of nodal points equals that the saddle points on the skin-friction line vector fields in eachpitch range; (2) for an annular or straight cascade with no-clearances at blade ends, the total number of saddle points is two more than that of nodal points on the skin-friction line fields in a pitch; (3) the total number of saddles in the secondary flow fields on cross-sections in cascade is one less than that of nodes; (4) in the section streamline vector fields on a meridian surface penetrating a flow passage, and on leading and trailing edge sections, the total number of nodes is equal to that of saddles; (5) on the streamline vector fields of a blade-to-blade surface, the total number of nodes is one less than that of saddles.
基金supported by the Japan Society for the Promotion of Science under KAKENHI Grant Nos.19F19379 and 20H04199。
文摘This paper demonstrates the importance of three-dimensional(3-D)piezoelectric coupling in the electromechanical behavior of piezoelectric devices using three-dimensional finite element analyses based on weak and strong coupling models for a thin cantilevered piezoelectric bimorph actuator.It is found that there is a significant difference between the strong and weak coupling solutions given by coupling direct and inverse piezoelectric effects(i.e.,piezoelectric coupling effect).In addition,there is significant longitudinal bending caused by the constraint of the inverse piezoelectric effect in the width direction at the fixed end(i.e.,3-D effect).Hence,modeling of these effects or 3-D piezoelectric coupling modeling is an electromechanical basis for the piezoelectric devices,which contributes to the accurate prediction of their behavior.
基金the Fundamental Research Funds for the Provincial Universities,China(No.702/000007020303)。
文摘A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analysis theory.The soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield criterion.Block analysis technique is employed to investigate the collapse of 3DRT.The model is divided into five different block types and added up to ten rigid blocks.According to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search proceeding.The results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square trapdoors.The critical stability ratios can be used in the design of underground excavation and support force.
文摘The intricate anatomy of the corpus cavernosum in both the flaccid and tumescent state has not been fully elucidated. We report our experience using a three-dimensional (3D) scanner to reconstruct cadaveric casts and compare them with 3D images of two prototypes of penile prosthesis. Two different models of the Titan Coloplast inflatable penile prosthesis were analyzed using a 3D scanner. The first was the standard model and the second was a newer model with a rounder silicone tip. Two cadaveric phalluses were harvested using Smooth-Cast 300Q polyurethane molding. The molds were excised and scanned along side the penile prosthesis. 3D scans were completed and analyzed using Leios Mesh software, and GOM Inspect software. The 3D scans demonstrated the mean human corporal radii 2 mm from the distal tip to be 36.51 mm (36.01-37.0 mm), which is an obtuse angle. The standard Titan penile prosthesis spherical radius at the same level was 202.52 mm, while the new silicone tip prosthesis had a radius of 139.33 mm. 3D mapping further demonstrated the trajectory of the cavernosa appeared curvilinear and the distal ends appeared blunt. The use of cadaveric cavernosal molds in combination with the 3D scanner allowed us to accurately image the corpus cavernosum for the first time. Our findings suggest that anatomically accurate corporal tips appear to be relatively blunt and that the new Titan silicone tip penile prosthesis more closely resembles the human corporal tip.
文摘With an application of topological analysis,in this paper the skin-friction line patterns on compressor and turbine cascade surfaces are depicted and the streamline patterns of the secondary flow fields in the cross-section of a curved pipe and a turbine cascade are drawn under given conditions.In addition the structures of vortices within three-dimensional viscous flow fields in cascades are analysed.
文摘The paper applies a mathematical model[1] for specular reflection to plain-knitted fabrics by using a three-dimensional analysis. Computer simulation of goniophotometric curves is generated based oa the model. Correction factors are introduced by taking into consideration of geometry of the instrument used. Comparison between the simulated and the measured curves of a straight monofilament yarn with various orientation angles is carried out and reasonable agreement has been obtained.
基金The National Key R&D Program of China under contract Nos 2018YFC1406202 and 2018YFC1406206the National University of Defense Technology under contract No.ZK18-03-29。
文摘In previous studies,Lagrangian analyses were used to assess large-scale ocean circulation,and the Lagrangian coherent structure could also reveal the evolution of the two-dimensional structure of the mesoscale eddies.However,few studies have demonstrated the three-dimensional structure of the mesoscale eddies via Lagrangian analysis.Compared with previous studies,which investigated the eddy structure via a Eulerian view,we used a Lagrangian view to provide a different perspective to study the eddy structure.An idealized cyclonic mesoscale eddy is built up over a seamount,and it presents downwelling inside the eddy and upwelling alongside the eddy formed within a closed circulation system.This structure is difficult to display via a Eulerian analysis.However,the trajectories of particles can well demonstrate the full cycle:the fluid sank and rotated inside the eddies,converged to the upwelling zone of the bottom layer and returned to the surface through upwelling.We also applied a Lagrangian analysis to a realistic simulation.As a significant phenomenon in the South China Sea,the dipole structure of the anticyclonic eddy(AE)/cyclonic eddy(CE)pair off of central Vietnam has been well studied but mainly at the sea surface.With a Lagrangian analysis,we illustrate the three-dimensional structure of the eddy pair:the fluid sank(rose)and rotated inside the AE(CE).More importantly,the trajectories of the particles suggested that there was no fluid exchange between the two eddies since the strong boundary jet separates them from each other.All the conclusions above have been verified and are supported by the computational error estimate.With a selected time step and integral period,the computational errors always present small values,although they increase with strong divergent and vertical diffusive flow.