A novel and simple technique to control the search direction of the differential mutation was proposed.In order to verify the performance of this method,ten widely used benchmark functions were chosen and the results ...A novel and simple technique to control the search direction of the differential mutation was proposed.In order to verify the performance of this method,ten widely used benchmark functions were chosen and the results were compared with the original differential evolution(DE)algorithm.Experimental results indicate that the search direction controlled DE algorithm obtains better results than the original DE algorithm in term of the solution quality and convergence rate.展开更多
In this paper we propose an algorithm based on the BFGS Quasi-Newton method to solve a linear program. The choice of this method is justified by its theoretical efficiency, the ease to determine a descent direction an...In this paper we propose an algorithm based on the BFGS Quasi-Newton method to solve a linear program. The choice of this method is justified by its theoretical efficiency, the ease to determine a descent direction and its fast convergence towards an optimal solution. Our proposed method is compared with Newton＇s method for linear program named lpnew, widely used as an optimization algorithm for classification problems.展开更多
As a typical fluid-solid interaction problem,vortex-induced vibration(VIV)is common in engineering,so it is vital to study its control mechanism.Numerical simulations of the active control of VIV of a cylinder are car...As a typical fluid-solid interaction problem,vortex-induced vibration(VIV)is common in engineering,so it is vital to study its control mechanism.Numerical simulations of the active control of VIV of a cylinder are carried out in this study.The splitter plate with harmonic oscillation is used as the control device for the dynamic response of the cylinder.The displacement response,lift and drag coefficient,vibration frequency of the cylinder,energy efficiency of control strategy,and characteristics of the flow field are widely analyzed to reveal the physical mechanism of the control system.The results show that the displacement response of the cylinder can be limited in a small range by the control without feedback in most cases except for high reduced velocity.In addition,the control strategy can be changed through feedback control to keep much superior control effects at the high reduced velocity.The oscillatory splitter plate delays the vortex shedding of shear layers generated on the cylinder,the wake vortices with opposite sense of rotation are paralleled with the streamwise direction,and crosswise distances of them are reduced.Thus,the lift on the cylinder is greatly decreased due to the modification of the flow pattern induced by the oscillatory splitter plate.展开更多
基金Project(2011FJ3016)supported by the Research Foundation of Science & Technology Office of Hunan Province,China
文摘A novel and simple technique to control the search direction of the differential mutation was proposed.In order to verify the performance of this method,ten widely used benchmark functions were chosen and the results were compared with the original differential evolution(DE)algorithm.Experimental results indicate that the search direction controlled DE algorithm obtains better results than the original DE algorithm in term of the solution quality and convergence rate.
文摘In this paper we propose an algorithm based on the BFGS Quasi-Newton method to solve a linear program. The choice of this method is justified by its theoretical efficiency, the ease to determine a descent direction and its fast convergence towards an optimal solution. Our proposed method is compared with Newton＇s method for linear program named lpnew, widely used as an optimization algorithm for classification problems.
基金supported by the National Natural Science Foundation of China(Grant No.11872174)the Fundamental Research Funds for the Central Universities(Grant No.B200202236)the Key Laboratory of Port,Waterway&Sedimentation Engineering Ministry of Communications,PRC(Grant No.Yk220001-2).
文摘As a typical fluid-solid interaction problem,vortex-induced vibration(VIV)is common in engineering,so it is vital to study its control mechanism.Numerical simulations of the active control of VIV of a cylinder are carried out in this study.The splitter plate with harmonic oscillation is used as the control device for the dynamic response of the cylinder.The displacement response,lift and drag coefficient,vibration frequency of the cylinder,energy efficiency of control strategy,and characteristics of the flow field are widely analyzed to reveal the physical mechanism of the control system.The results show that the displacement response of the cylinder can be limited in a small range by the control without feedback in most cases except for high reduced velocity.In addition,the control strategy can be changed through feedback control to keep much superior control effects at the high reduced velocity.The oscillatory splitter plate delays the vortex shedding of shear layers generated on the cylinder,the wake vortices with opposite sense of rotation are paralleled with the streamwise direction,and crosswise distances of them are reduced.Thus,the lift on the cylinder is greatly decreased due to the modification of the flow pattern induced by the oscillatory splitter plate.
