The Sonreb and Core (SRC) combined method is proposed to assess the concrete compression strength of mass concrete structures.Artificial neural network is employed together with the SRC combined method to obtain the o...The Sonreb and Core (SRC) combined method is proposed to assess the concrete compression strength of mass concrete structures.Artificial neural network is employed together with the SRC combined method to obtain the optimal core number.The artificial neural network is trained based on data from different testing methods.The procedure of using artificial neural network to assess the concrete strength is described.It proves that the SRC combined method is superior in many aspects and artificial the presented neural network has a high efficiency and reliability.The combined method using artificial intelligence is promising in the strength assessment of mass concrete structures such as the dam,the anchor of the suspension bridge,etc.展开更多
The study focused on the influence of various engineering factors on the strength of rigid airport pavement.Based on different test schemes,we established indoor and outdoor tests,compared the strength test results,an...The study focused on the influence of various engineering factors on the strength of rigid airport pavement.Based on different test schemes,we established indoor and outdoor tests,compared the strength test results,and quantitatively analyzed the impacts of mechanical damage,maintenance conditions,and construction technology on the splitting strength of rigid airport pavement.We further fitted the correction coefficients of the split-ting strength of core samples with different height-diameter ratios.Dempster-Shafer(D-S)evidence theory and gray correlation analysis were used to analyze the correlation between the influencing factors and the pavement splitting tensile strength.The impor-tance of the factors affecting the rigid airport pavement strength was then determined.The results showed that the loss rates of pavement splitting tensile strength caused by dif-ferences in construction technology,curing conditions,and mechanical damage were 6.90%,4.43%,and 2.11%,respectively.The correlation between each influencing factor and pavement tensile strength was good.The degree of influence decreased in the follow-ing order:construction technology>curing conditions>mechanical damage.These find-ings can help the reasonable allocation of resources on construction sites.展开更多
Oscillations caused by small-signal instability have been widely observed in AC grids with grid-following(GFL)and grid-forming(GFM)converters.The generalized short-circuit ratio is commonly used to assess the strength...Oscillations caused by small-signal instability have been widely observed in AC grids with grid-following(GFL)and grid-forming(GFM)converters.The generalized short-circuit ratio is commonly used to assess the strength of GFL converters when integrated with weak AC systems at risk of oscillation.This paper provides the grid strength assessment method to evaluate the small-signal synchronization stability of GFL and GFM converters integrated systems.First,the admittance and impedance matrices of the GFL and GFM converters are analyzed to identify the frequency bands associated with negative damping in oscillation modes dominated by heterogeneous synchronization control.Secondly,based on the interaction rules between the short-circuit ratio and the different oscillation modes,an equivalent circuit is proposed to simplify the grid strength assessment through the topological transformation of the AC grid.The risk of sub-synchronization and low-frequency oscillations,influenced by GFL and GFM converters,is then reformulated as a semi-definite programming(SDP)model,incorporating the node admittance matrix and grid-connected device capacities.The effectiveness of the proposed method is demonstrated through a case analysis.展开更多
Increased neck strength has been linked to a potential decrease in traumatic brain injuries(TBI).The purpose was to determine the efficacy of a neck-strengthening protocol using a novel neck-strengthening device to in...Increased neck strength has been linked to a potential decrease in traumatic brain injuries(TBI).The purpose was to determine the efficacy of a neck-strengthening protocol using a novel neck-strengthening device to increase isometric neck strength and rate of force development(RFD).Utilizing self-generated centripetal force,participants trained for 14 weeks.A linear mixed model was used to analyze the relationship between post-assessment measurements and pre-assessments measurements,while accounting for repeated measure random effect at the individual level,and a regular random error term.RFD values were 4.344 times higher in the clockwise direction and 5.978 times higher in the counterclockwise direction when comparing pre and post assessment measurements.Isometric neck strength increased significantly(p<0.05)in the cervical extension(p=0.010)and left lateral flexion(p=0.009)directions.The results can be used in strength training and clinical settings to potentially reduce the incidence of TBI.展开更多
From the case study, the nature defects of single-hull vessel were discussed to compare the safety level between single-hull vessel and double-hull vessel. Data was chosen from both investigation and research from ABS...From the case study, the nature defects of single-hull vessel were discussed to compare the safety level between single-hull vessel and double-hull vessel. Data was chosen from both investigation and research from ABS, as well as simulation by similar kind of vessel in model calculation. The study underscores the main defects of single-hull vessel for prevention of their losses, mentioning the most importa</span><span style="font-family:Verdana;"></span><span style="font-family:"">nt measures taken by IMO for improvement of vessel safety. In the work, a critical analysis of the methodology of the International Association of Classification Societies (IACS) for calculation of sectional efforts induced by waves in vessel’s hull is described. In the end, the advantage of double-hull vessel was determined and the reason to eliminate single-hull vessel was proved again.展开更多
Virtual reality(VR)technology revitalises rehabilitation training by creating rich,interactive virtual rehabilitation scenes and tasks that deeply engage patients.Robotics with immersive VR environments have the poten...Virtual reality(VR)technology revitalises rehabilitation training by creating rich,interactive virtual rehabilitation scenes and tasks that deeply engage patients.Robotics with immersive VR environments have the potential to significantly enhance the sense of immersion for patients during training.This paper proposes a rehabilitation robot system.The system integrates a VR environment,the exoskeleton entity,and research on rehabilitation assessment metrics derived from surface electromyographic signal(sEMG).Employing more realistic and engaging virtual stimuli,this method guides patients to actively participate,thereby enhancing the effectiveness of neural connection reconstruction—an essential aspect of rehabilitation.Furthermore,this study introduces a muscle activation model that merges linear and non-linear states of muscle,avoiding the impact of non-linear shape factors on model accuracy present in traditional models.A muscle strength assessment model based on optimised generalised regression(WOAGRNN)is also proposed,with a root mean square error of 0.017,347 and a mean absolute percentage error of 1.2461%,serving as critical assessment indicators for the effectiveness of rehabilitation.Finally,the system is preliminarily applied in human movement experiments,validating the practicality and potential effectiveness of VRcentred rehabilitation strategies in medical recovery.展开更多
基金Sponsored by the Priority Academic Program Development Foundation of Jiangsu Higher Education Institute(Grant No. CE01-3)the NSFC for Outstanding Youth Fund (Grant No. 50725828),the NSFC for Young Scholars (Grant No. 50908046)+1 种基金the Ph. D. Programs Foundation of Ministry of Education of China (Grant No. 200802861012)the Basic Scientific & Research Fund of Southeast University (Grant No. Seucx201106)
文摘The Sonreb and Core (SRC) combined method is proposed to assess the concrete compression strength of mass concrete structures.Artificial neural network is employed together with the SRC combined method to obtain the optimal core number.The artificial neural network is trained based on data from different testing methods.The procedure of using artificial neural network to assess the concrete strength is described.It proves that the SRC combined method is superior in many aspects and artificial the presented neural network has a high efficiency and reliability.The combined method using artificial intelligence is promising in the strength assessment of mass concrete structures such as the dam,the anchor of the suspension bridge,etc.
基金grateful to the Shanghai Sailing Program(No.20YF1431900)for supporting this study.
文摘The study focused on the influence of various engineering factors on the strength of rigid airport pavement.Based on different test schemes,we established indoor and outdoor tests,compared the strength test results,and quantitatively analyzed the impacts of mechanical damage,maintenance conditions,and construction technology on the splitting strength of rigid airport pavement.We further fitted the correction coefficients of the split-ting strength of core samples with different height-diameter ratios.Dempster-Shafer(D-S)evidence theory and gray correlation analysis were used to analyze the correlation between the influencing factors and the pavement splitting tensile strength.The impor-tance of the factors affecting the rigid airport pavement strength was then determined.The results showed that the loss rates of pavement splitting tensile strength caused by dif-ferences in construction technology,curing conditions,and mechanical damage were 6.90%,4.43%,and 2.11%,respectively.The correlation between each influencing factor and pavement tensile strength was good.The degree of influence decreased in the follow-ing order:construction technology>curing conditions>mechanical damage.These find-ings can help the reasonable allocation of resources on construction sites.
基金supported by the Science and Technology Project of State Grid Zhejiang Electric Power Co.,Ltd.(No.5211DS24000D)。
文摘Oscillations caused by small-signal instability have been widely observed in AC grids with grid-following(GFL)and grid-forming(GFM)converters.The generalized short-circuit ratio is commonly used to assess the strength of GFL converters when integrated with weak AC systems at risk of oscillation.This paper provides the grid strength assessment method to evaluate the small-signal synchronization stability of GFL and GFM converters integrated systems.First,the admittance and impedance matrices of the GFL and GFM converters are analyzed to identify the frequency bands associated with negative damping in oscillation modes dominated by heterogeneous synchronization control.Secondly,based on the interaction rules between the short-circuit ratio and the different oscillation modes,an equivalent circuit is proposed to simplify the grid strength assessment through the topological transformation of the AC grid.The risk of sub-synchronization and low-frequency oscillations,influenced by GFL and GFM converters,is then reformulated as a semi-definite programming(SDP)model,incorporating the node admittance matrix and grid-connected device capacities.The effectiveness of the proposed method is demonstrated through a case analysis.
文摘Increased neck strength has been linked to a potential decrease in traumatic brain injuries(TBI).The purpose was to determine the efficacy of a neck-strengthening protocol using a novel neck-strengthening device to increase isometric neck strength and rate of force development(RFD).Utilizing self-generated centripetal force,participants trained for 14 weeks.A linear mixed model was used to analyze the relationship between post-assessment measurements and pre-assessments measurements,while accounting for repeated measure random effect at the individual level,and a regular random error term.RFD values were 4.344 times higher in the clockwise direction and 5.978 times higher in the counterclockwise direction when comparing pre and post assessment measurements.Isometric neck strength increased significantly(p<0.05)in the cervical extension(p=0.010)and left lateral flexion(p=0.009)directions.The results can be used in strength training and clinical settings to potentially reduce the incidence of TBI.
文摘From the case study, the nature defects of single-hull vessel were discussed to compare the safety level between single-hull vessel and double-hull vessel. Data was chosen from both investigation and research from ABS, as well as simulation by similar kind of vessel in model calculation. The study underscores the main defects of single-hull vessel for prevention of their losses, mentioning the most importa</span><span style="font-family:Verdana;"></span><span style="font-family:"">nt measures taken by IMO for improvement of vessel safety. In the work, a critical analysis of the methodology of the International Association of Classification Societies (IACS) for calculation of sectional efforts induced by waves in vessel’s hull is described. In the end, the advantage of double-hull vessel was determined and the reason to eliminate single-hull vessel was proved again.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFB4700701National Outstanding Youth Science Fund Project of National Natural Science Foundation of China,Grant/Award Number:52025054。
文摘Virtual reality(VR)technology revitalises rehabilitation training by creating rich,interactive virtual rehabilitation scenes and tasks that deeply engage patients.Robotics with immersive VR environments have the potential to significantly enhance the sense of immersion for patients during training.This paper proposes a rehabilitation robot system.The system integrates a VR environment,the exoskeleton entity,and research on rehabilitation assessment metrics derived from surface electromyographic signal(sEMG).Employing more realistic and engaging virtual stimuli,this method guides patients to actively participate,thereby enhancing the effectiveness of neural connection reconstruction—an essential aspect of rehabilitation.Furthermore,this study introduces a muscle activation model that merges linear and non-linear states of muscle,avoiding the impact of non-linear shape factors on model accuracy present in traditional models.A muscle strength assessment model based on optimised generalised regression(WOAGRNN)is also proposed,with a root mean square error of 0.017,347 and a mean absolute percentage error of 1.2461%,serving as critical assessment indicators for the effectiveness of rehabilitation.Finally,the system is preliminarily applied in human movement experiments,validating the practicality and potential effectiveness of VRcentred rehabilitation strategies in medical recovery.
