In this paper, the behavior of barrel-vaulted structures undergoing rocking of the abutments and the effectiveness of a few retrofit solutions are discussed. The comprehension of the structural performance of vault-ab...In this paper, the behavior of barrel-vaulted structures undergoing rocking of the abutments and the effectiveness of a few retrofit solutions are discussed. The comprehension of the structural performance of vault-abutment systems is fundamental for their seismic vulnerability assessment, and for the design of efficient strengthening techniques. In the paper, traditional techniques such as extrados thin concrete slab or masonry spandrel walls as well as an innovative solution with an extrados thin improved lime mortar slab reinforced by means of glass fiber mesh are considered. The different strengthening solutions are studied and compared on the basis of the results of non linear numerical analyses and by reference to a simplified analytical approach. Numerical and analytical models are validated through comparison with the results of a recent experimental study focusing on the behavior of vaulted masonry structures subjected to rocking of the abutments. The validated models can be used by engineers for the seismic vulnerability assessment of masonry vaulted structures as well as for the proportioning of possible extrados strengthening solutions, and will be used in the future to explore different structural system configurations.展开更多
AIM:To predict the post-operative vault and the suitable size of the implantable collamer lens(ICL)by comparing the performance of multiple artificial intelligence(AI)algorithms.METHODS:A retrospective analysis of 83 ...AIM:To predict the post-operative vault and the suitable size of the implantable collamer lens(ICL)by comparing the performance of multiple artificial intelligence(AI)algorithms.METHODS:A retrospective analysis of 83 patients with 132 eyes was conducted from 2020 to 2023.All patients underwent implantation of EVO-V4C ICLs.ICLs were selected based on STAAR’s recommended formula.Postoperative vault values were measured using anterior segment optical coherence tomography(ASOCT).First,feature selection was performed on patients’preoperative examination parameters to identify those most closely related to postoperative vault and incorporate them into the machine learning model.Subsequently,four regression models,namely MLP,XGBoost,RFR,and KNN,were employed to predict the vault,and their predictive performances were compared.The ICL size was set as the prediction target,with the vault and other input features serving as new inputs for predicting the ICL size.RESULTS:Among all preoperative parameters,16 parameters were most closely related to postoperative vault and were included in the prediction model.In vault prediction,XGBoost performed the best in the regression model(R^(2)=0.9999),followed by MLP(R^(2)=0.9987)and RFR(R^(2)=0.8982),while the KNN model had the lowest predictive performance(R^(2)=0.3852).XGBoost achieved a prediction accuracy of 99.8%,MLP had a prediction accuracy of 98.9%,while RFR and KNN had accuracies of 87.1%and 57.4%,respectively.CONCLUSION:AI effectively predicts postoperative vault and determines ICL size.XGBoost outperforms other machine-learning algorithms tested.Its accurate predictions help ophthalmologists choose the right ICL size,ensuring proper vaulting.展开更多
Phakic intraocular lens implantation has become one of the important means of correcting refractive errors today.Among them,the implantable collamer lens(ICL)is favored for its wide range of correction,excellent optic...Phakic intraocular lens implantation has become one of the important means of correcting refractive errors today.Among them,the implantable collamer lens(ICL)is favored for its wide range of correction,excellent optical quality,and high safety,but the risks of postoperative complications such as glaucoma and anterior subcapsular opacification still exist.Vault is an important indicator for evaluating the safety after ICL implantation,and its ideal state is crucial for preventing complications.Studies have shown that iris morphology has a significant impact on vault.In order to further optimize surgical outcomes and improve surgical safety,this review comprehensively reviews the research progress of iris-related parameters in ICL implantation and discusses the importance of various parameters in preoperative evaluation and postoperative follow-up.展开更多
AIM:To determine the factors related to preoperative ocular characters that are predictive of insufficient vault(<250μm)after implantable collamer lens(ICL V4c;STAAR Surgical)implantation.METHODS:The participants ...AIM:To determine the factors related to preoperative ocular characters that are predictive of insufficient vault(<250μm)after implantable collamer lens(ICL V4c;STAAR Surgical)implantation.METHODS:The participants underwent ICL surgery and were divided into the low(<250μm)and normal(250-1000μm)vault groups based on the postoperative vault at 3mo.The preoperative biometric parameters and clinical outcomes were compared between the two groups.The relationship between the 3-month vault values and preoperative ocular parameters were evaluated by Generalized estimating equations.RESULTS:Sixteen(23 eyes)and 36 patients(63 eyes)were in the low and normal vault groups,respectively.All implantation procedures were uneventful with no cataract formation in the early postoperative period.The sulcusto-sulcus lens rise(STSL)and iris ciliary angle(ICA)were correlated with vault at 3mo after surgery.Every 0.1 mm increase in STSL was associated with 38.9μm decrease in the postoperative 3-month vault.A rise of 1 degree in ICA is associated with a reduction of 4μm in vault.CONCLUSION:Eyes with a narrow ciliary sulcus are associated with a higher rate of low vault after ICL implantation,suggesting a need for adjustments to the ICL size in these patients.Evaluating the characteristics of the ciliary sulcus contributes valuable information to predict low vault after surgery.展开更多
Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed...Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed,while the magnitude of elastic potential energy depends on height.Therefore,the run-up speed determines the vaulter’s performance in pole vault to a certain extent.the horizontal speed of the pole-holding approach phase transitioning into vertical upward speed plays a crucial role in executing pole vault techniques,and the model of approaching speed establishes a theoretical foundation for vaulters to break through the pole limitation.In terms of specialized technical assistance in speed training,short-distance speed exercises are used in the approaching phase;in the swinging phase,gymnastic rings,single bar and suspension rope exercises are employed for suspension;in the stretch phase,trampoline exercises play a important role in rotation phase,etc.展开更多
In accordance with the relative movement between end-milling cutter and workpiece surface, a theoretical generation model for milled surface was established with the movement error of principal axle considered. Then t...In accordance with the relative movement between end-milling cutter and workpiece surface, a theoretical generation model for milled surface was established with the movement error of principal axle considered. Then the milled surfaces under various cutting condition were simulated, the results of which showed that end milled surfaces were of "vaulted profile", heights of surface irregularty at various points to be different with maximum value in the middle and smaller at both sides, the difference were determined by diameter of milling cutter, feeding speed, ratio between the diameter of milling cutter and teeth point curve radius and width of workpiece. The study results can be applied to quality prediction of milled surfaces for precision and/or super precision milling operation.展开更多
文摘In this paper, the behavior of barrel-vaulted structures undergoing rocking of the abutments and the effectiveness of a few retrofit solutions are discussed. The comprehension of the structural performance of vault-abutment systems is fundamental for their seismic vulnerability assessment, and for the design of efficient strengthening techniques. In the paper, traditional techniques such as extrados thin concrete slab or masonry spandrel walls as well as an innovative solution with an extrados thin improved lime mortar slab reinforced by means of glass fiber mesh are considered. The different strengthening solutions are studied and compared on the basis of the results of non linear numerical analyses and by reference to a simplified analytical approach. Numerical and analytical models are validated through comparison with the results of a recent experimental study focusing on the behavior of vaulted masonry structures subjected to rocking of the abutments. The validated models can be used by engineers for the seismic vulnerability assessment of masonry vaulted structures as well as for the proportioning of possible extrados strengthening solutions, and will be used in the future to explore different structural system configurations.
基金Supported by the National Natural Science Foundation of China(No.82271100)the Jiangsu Science and Technology Support Program(No.BE2022805)the Clinical Skills Enhancement Program of Jiangsu Province Hospital(No.JSPH-MC-2022-24).
文摘AIM:To predict the post-operative vault and the suitable size of the implantable collamer lens(ICL)by comparing the performance of multiple artificial intelligence(AI)algorithms.METHODS:A retrospective analysis of 83 patients with 132 eyes was conducted from 2020 to 2023.All patients underwent implantation of EVO-V4C ICLs.ICLs were selected based on STAAR’s recommended formula.Postoperative vault values were measured using anterior segment optical coherence tomography(ASOCT).First,feature selection was performed on patients’preoperative examination parameters to identify those most closely related to postoperative vault and incorporate them into the machine learning model.Subsequently,four regression models,namely MLP,XGBoost,RFR,and KNN,were employed to predict the vault,and their predictive performances were compared.The ICL size was set as the prediction target,with the vault and other input features serving as new inputs for predicting the ICL size.RESULTS:Among all preoperative parameters,16 parameters were most closely related to postoperative vault and were included in the prediction model.In vault prediction,XGBoost performed the best in the regression model(R^(2)=0.9999),followed by MLP(R^(2)=0.9987)and RFR(R^(2)=0.8982),while the KNN model had the lowest predictive performance(R^(2)=0.3852).XGBoost achieved a prediction accuracy of 99.8%,MLP had a prediction accuracy of 98.9%,while RFR and KNN had accuracies of 87.1%and 57.4%,respectively.CONCLUSION:AI effectively predicts postoperative vault and determines ICL size.XGBoost outperforms other machine-learning algorithms tested.Its accurate predictions help ophthalmologists choose the right ICL size,ensuring proper vaulting.
基金Key Research and Development Projects of Zhejiang Science and Technology Plan(No.2021C03103)Research and Development Plan of Zhejiang Science and Technology Department(No.2023C03089)Scientific Research Project of Zhejiang Provincial Department of Education(No.Y202456401)。
文摘Phakic intraocular lens implantation has become one of the important means of correcting refractive errors today.Among them,the implantable collamer lens(ICL)is favored for its wide range of correction,excellent optical quality,and high safety,but the risks of postoperative complications such as glaucoma and anterior subcapsular opacification still exist.Vault is an important indicator for evaluating the safety after ICL implantation,and its ideal state is crucial for preventing complications.Studies have shown that iris morphology has a significant impact on vault.In order to further optimize surgical outcomes and improve surgical safety,this review comprehensively reviews the research progress of iris-related parameters in ICL implantation and discusses the importance of various parameters in preoperative evaluation and postoperative follow-up.
基金Supported by National Natural Science Foundation of China(No.81900910)Natural Science Foundation of Zhejiang Province(No.LQ19H120003)Basic Scientific Research Project of Wenzhou(No.Y2023809).
文摘AIM:To determine the factors related to preoperative ocular characters that are predictive of insufficient vault(<250μm)after implantable collamer lens(ICL V4c;STAAR Surgical)implantation.METHODS:The participants underwent ICL surgery and were divided into the low(<250μm)and normal(250-1000μm)vault groups based on the postoperative vault at 3mo.The preoperative biometric parameters and clinical outcomes were compared between the two groups.The relationship between the 3-month vault values and preoperative ocular parameters were evaluated by Generalized estimating equations.RESULTS:Sixteen(23 eyes)and 36 patients(63 eyes)were in the low and normal vault groups,respectively.All implantation procedures were uneventful with no cataract formation in the early postoperative period.The sulcusto-sulcus lens rise(STSL)and iris ciliary angle(ICA)were correlated with vault at 3mo after surgery.Every 0.1 mm increase in STSL was associated with 38.9μm decrease in the postoperative 3-month vault.A rise of 1 degree in ICA is associated with a reduction of 4μm in vault.CONCLUSION:Eyes with a narrow ciliary sulcus are associated with a higher rate of low vault after ICL implantation,suggesting a need for adjustments to the ICL size in these patients.Evaluating the characteristics of the ciliary sulcus contributes valuable information to predict low vault after surgery.
文摘Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed,while the magnitude of elastic potential energy depends on height.Therefore,the run-up speed determines the vaulter’s performance in pole vault to a certain extent.the horizontal speed of the pole-holding approach phase transitioning into vertical upward speed plays a crucial role in executing pole vault techniques,and the model of approaching speed establishes a theoretical foundation for vaulters to break through the pole limitation.In terms of specialized technical assistance in speed training,short-distance speed exercises are used in the approaching phase;in the swinging phase,gymnastic rings,single bar and suspension rope exercises are employed for suspension;in the stretch phase,trampoline exercises play a important role in rotation phase,etc.
文摘In accordance with the relative movement between end-milling cutter and workpiece surface, a theoretical generation model for milled surface was established with the movement error of principal axle considered. Then the milled surfaces under various cutting condition were simulated, the results of which showed that end milled surfaces were of "vaulted profile", heights of surface irregularty at various points to be different with maximum value in the middle and smaller at both sides, the difference were determined by diameter of milling cutter, feeding speed, ratio between the diameter of milling cutter and teeth point curve radius and width of workpiece. The study results can be applied to quality prediction of milled surfaces for precision and/or super precision milling operation.
