An evaluation of existing strength of concrete columns confined with fiber-reinforced polymer( FRP) was presented with extensive collection of experimental data. According to the evaluation results, artificial neural ...An evaluation of existing strength of concrete columns confined with fiber-reinforced polymer( FRP) was presented with extensive collection of experimental data. According to the evaluation results, artificial neural networks( ANNs) model to predict the ultimate strength of FRP confined column with different shapes was proposed. The models had seven inputs including the column length,the tensile strength of the FRP in the hoop direction,the total thickness of FRP,the diameter of the concrete specimen,the elastic modulus of FRP,the corner radius and the concrete compressive strength. The compressive strength of the confined concrete was the output data. The results reveal that the proposed models have good prediction and generalization capacity with acceptable errors.展开更多
Natural orifice transluminal endoscopic surgery(NOTES)associated with less pain,shorter hospital stay,and outstanding cosmetic results has drawn considerable attention from the academic community.For NOTES,pneumoperit...Natural orifice transluminal endoscopic surgery(NOTES)associated with less pain,shorter hospital stay,and outstanding cosmetic results has drawn considerable attention from the academic community.For NOTES,pneumoperitoneum is an essential technology to obtain intraperitoneal surgical space,which,however,can have some serious adverse hemodynamic effects.In this paper,we propose a novel intra-abdominal wall-lifting device that can replace the pneumoperitoneum functionally for transvaginal NOTES(vNOTES).The device consists mainly of two layers of elastic strips,namely,the outer strips that are used to lift the abdominal wall for surgical exposure and the inner strip with a camera mounted that can rotate to provide a wide surgical field of view.With the design,gasless vNOTES can be carried out with 82.74% of the operative field provided by pneumoperitoneum,eliminating all complications associated with gas insufflation.The design principle and kinematic analysis of the device are discussed in detail and validated by experiments.Finally,a prototype is fabricated to demonstrate the feasibility of the proposed concept.展开更多
Nine square concrete columns including 6 CFRP/ECCs and 3 concrete columns are prepared,which have cross-section of 200 mm×200 mm and height of 600 mm.The CFRP tubes with fibers oriented at hoop direction were man...Nine square concrete columns including 6 CFRP/ECCs and 3 concrete columns are prepared,which have cross-section of 200 mm×200 mm and height of 600 mm.The CFRP tubes with fibers oriented at hoop direction were manufactured to have 3 or 5 layers of CFRP with 10 mm, 20 mm,or 40 mm rounding corner radii at vertical edges.A 100 mm overlap in the direction of fibers was provided to ensure proper bond.Uniaxial compression tests were conducted to investigate the compressive behavior.It is evident that the CFRP tube confinement can improve the behavior of concrete core,in terms of axial compressive strength or axial deformability.Test results show that the stress-strain behavior of CFRP/ECCs vary with different confinement parameters,such as the number of confinement layers and the rounding corner radius.展开更多
In this study,nine square concrete columns,including six CFRP/ECCs and three plain concrete control specimen columns,were prepared. The CFRP tubes with fibers oriented in the hoop direction were manufactured with 10,2...In this study,nine square concrete columns,including six CFRP/ECCs and three plain concrete control specimen columns,were prepared. The CFRP tubes with fibers oriented in the hoop direction were manufactured with 10,20,or 40 mm rounded corner radii at vertical edges. A 100 mm overlap in the direction of fibers was provided to ensure a proper bond. Uniaxial compression tests were conducted to investigate the compressive behaviors including the axial strength,stress-strain response,and ductility. It is evident that the CFRP tube confinement can improve the compressive behavior of concrete core,in terms of axial compressive strength or axial deformability. Based on the experimental results and some existing test database attained by other researchers,a design-oriented model is developed. The predictions of the model for CFRP/ECCs show good agreement with test results.展开更多
The problem of reconstructing n-by-n structured matrix signal X=(x1,...,xn)via convex optimization is investigated,where each column xj is a vector of s-sparsity and all columns have the same l1-norm value.In this pap...The problem of reconstructing n-by-n structured matrix signal X=(x1,...,xn)via convex optimization is investigated,where each column xj is a vector of s-sparsity and all columns have the same l1-norm value.In this paper,the convex programming problem was solved with noise-free or noisy measurements.The uniform sufficient conditions were established which are very close to necessary conditions and non-uniform conditions were also discussed.In addition,stronger conditions were investigated to guarantee the reconstructed signal’s support stability,sign stability and approximation-error robustness.Moreover,with the convex geometric approach in random measurement setting,one of the critical ingredients in this contribution is to estimate the related widths’bounds in case of Gaussian and non-Gaussian distributions.These bounds were explicitly controlled by signal’s structural parameters r and s which determined matrix signal’s column-wise sparsity and l1-column-flatness respectively.This paper provides a relatively complete theory on column-wise sparse and l1-column-flat matrix signal reconstruction,as well as a heuristic foundation for dealing with more complicated high-order tensor signals in,e.g.,statistical big data analysis and related data-intensive applications.展开更多
基金National Natural Science Foundation of China(No.51278391)
文摘An evaluation of existing strength of concrete columns confined with fiber-reinforced polymer( FRP) was presented with extensive collection of experimental data. According to the evaluation results, artificial neural networks( ANNs) model to predict the ultimate strength of FRP confined column with different shapes was proposed. The models had seven inputs including the column length,the tensile strength of the FRP in the hoop direction,the total thickness of FRP,the diameter of the concrete specimen,the elastic modulus of FRP,the corner radius and the concrete compressive strength. The compressive strength of the confined concrete was the output data. The results reveal that the proposed models have good prediction and generalization capacity with acceptable errors.
文摘Natural orifice transluminal endoscopic surgery(NOTES)associated with less pain,shorter hospital stay,and outstanding cosmetic results has drawn considerable attention from the academic community.For NOTES,pneumoperitoneum is an essential technology to obtain intraperitoneal surgical space,which,however,can have some serious adverse hemodynamic effects.In this paper,we propose a novel intra-abdominal wall-lifting device that can replace the pneumoperitoneum functionally for transvaginal NOTES(vNOTES).The device consists mainly of two layers of elastic strips,namely,the outer strips that are used to lift the abdominal wall for surgical exposure and the inner strip with a camera mounted that can rotate to provide a wide surgical field of view.With the design,gasless vNOTES can be carried out with 82.74% of the operative field provided by pneumoperitoneum,eliminating all complications associated with gas insufflation.The design principle and kinematic analysis of the device are discussed in detail and validated by experiments.Finally,a prototype is fabricated to demonstrate the feasibility of the proposed concept.
文摘Nine square concrete columns including 6 CFRP/ECCs and 3 concrete columns are prepared,which have cross-section of 200 mm×200 mm and height of 600 mm.The CFRP tubes with fibers oriented at hoop direction were manufactured to have 3 or 5 layers of CFRP with 10 mm, 20 mm,or 40 mm rounding corner radii at vertical edges.A 100 mm overlap in the direction of fibers was provided to ensure proper bond.Uniaxial compression tests were conducted to investigate the compressive behavior.It is evident that the CFRP tube confinement can improve the behavior of concrete core,in terms of axial compressive strength or axial deformability.Test results show that the stress-strain behavior of CFRP/ECCs vary with different confinement parameters,such as the number of confinement layers and the rounding corner radius.
文摘In this study,nine square concrete columns,including six CFRP/ECCs and three plain concrete control specimen columns,were prepared. The CFRP tubes with fibers oriented in the hoop direction were manufactured with 10,20,or 40 mm rounded corner radii at vertical edges. A 100 mm overlap in the direction of fibers was provided to ensure a proper bond. Uniaxial compression tests were conducted to investigate the compressive behaviors including the axial strength,stress-strain response,and ductility. It is evident that the CFRP tube confinement can improve the compressive behavior of concrete core,in terms of axial compressive strength or axial deformability. Based on the experimental results and some existing test database attained by other researchers,a design-oriented model is developed. The predictions of the model for CFRP/ECCs show good agreement with test results.
文摘The problem of reconstructing n-by-n structured matrix signal X=(x1,...,xn)via convex optimization is investigated,where each column xj is a vector of s-sparsity and all columns have the same l1-norm value.In this paper,the convex programming problem was solved with noise-free or noisy measurements.The uniform sufficient conditions were established which are very close to necessary conditions and non-uniform conditions were also discussed.In addition,stronger conditions were investigated to guarantee the reconstructed signal’s support stability,sign stability and approximation-error robustness.Moreover,with the convex geometric approach in random measurement setting,one of the critical ingredients in this contribution is to estimate the related widths’bounds in case of Gaussian and non-Gaussian distributions.These bounds were explicitly controlled by signal’s structural parameters r and s which determined matrix signal’s column-wise sparsity and l1-column-flatness respectively.This paper provides a relatively complete theory on column-wise sparse and l1-column-flat matrix signal reconstruction,as well as a heuristic foundation for dealing with more complicated high-order tensor signals in,e.g.,statistical big data analysis and related data-intensive applications.
