Focusing on the single machine scheduling problem which minimizes the total completion time in the presence of dynamic job arrivals, a rolling optimization scheduling algorithm is proposed based on the analysis of the...Focusing on the single machine scheduling problem which minimizes the total completion time in the presence of dynamic job arrivals, a rolling optimization scheduling algorithm is proposed based on the analysis of the character and structure of scheduling. An optimal scheduling strategy in collision window is presented. Performance evaluation of this algorithm is given. Simulation indicates that the proposed algorithm is better than other common heuristic algorithms on both the total performance and stability.展开更多
A theoretical investigation of fluid flow,heat transfer and solidification(solidification transfer phenomena,STP)was presented which coupled with direct-current(DC)magnetic fields in a high-speed strip-casting metal d...A theoretical investigation of fluid flow,heat transfer and solidification(solidification transfer phenomena,STP)was presented which coupled with direct-current(DC)magnetic fields in a high-speed strip-casting metal delivery system.The bidirectional interaction between the STP and DC magnetic fields was simplified as a unilateral one,and the fully coupled solidification transport equations were numerically solved by the finite volume method(FVM).While the magnetic field contours for a localized DC magnetic field were calculated by software ANSYS and then incorporated into a three-dimensional(3-D)steady model of the liquid cavity in the mold by means of indirect coupling.A new FVM-based direct-SIMPLE algorithm was adopted to solve the iterations of pressure-velocity(P-V).The braking effects of DC magnetic fields with various configurations were evaluated and compared with those without static magnetic field(SMF).The results show that 0.6 T magnetic field with combination configuration contributes to forming an isokinetic feeding of melt,the re-circulation zone is shifted towards the back wall of reservoir,and the velocity difference on the direction of height decreases from 0.1 m/s to 0.Furthermore,the thickness of solidified skull increases uniformly from 0.45 mm to 1.36 mm on the chilled substrate(belt)near the exit.展开更多
针对电动调节阀控制系统在实际生产过程中存在的非线性、多扰动等问题,提出一种基于改进蚁群算法优化单神经元PID(proportional integral derivative)的控制方法并将其应用于阀门开度控制中。该方法利用单神经元网络的自学习和自适应能...针对电动调节阀控制系统在实际生产过程中存在的非线性、多扰动等问题,提出一种基于改进蚁群算法优化单神经元PID(proportional integral derivative)的控制方法并将其应用于阀门开度控制中。该方法利用单神经元网络的自学习和自适应能力,实现PID控制参数的在线整定,并采用改进的蚁群优化算法优化单神经元PID中的学习速率和神经元比例系数,有效克服了单神经元PID中的学习速率和神经元比例系数因经验设定而无法达到预期控制效果的不足。仿真对比结果显示,相比于传统PID、单神经元PID以及基于蚁群优化算法优化单神经元PID 3种控制方法,本文提出的控制方法超调量分别减少了10.2%、6.1%和1.8%,同时调节时间也相应缩短了0.22、0.07、0.03 s,并且表现出更强的自适应和抗干扰能力,能够使阀门开度控制更加稳定可靠。展开更多
文摘Focusing on the single machine scheduling problem which minimizes the total completion time in the presence of dynamic job arrivals, a rolling optimization scheduling algorithm is proposed based on the analysis of the character and structure of scheduling. An optimal scheduling strategy in collision window is presented. Performance evaluation of this algorithm is given. Simulation indicates that the proposed algorithm is better than other common heuristic algorithms on both the total performance and stability.
基金Projects(51071062,51271068,51274077)supported by the National Natural Science Foundation of ChinaProject(2011CB605504)supported by the National Basic Research Program(973 Program)of China
文摘A theoretical investigation of fluid flow,heat transfer and solidification(solidification transfer phenomena,STP)was presented which coupled with direct-current(DC)magnetic fields in a high-speed strip-casting metal delivery system.The bidirectional interaction between the STP and DC magnetic fields was simplified as a unilateral one,and the fully coupled solidification transport equations were numerically solved by the finite volume method(FVM).While the magnetic field contours for a localized DC magnetic field were calculated by software ANSYS and then incorporated into a three-dimensional(3-D)steady model of the liquid cavity in the mold by means of indirect coupling.A new FVM-based direct-SIMPLE algorithm was adopted to solve the iterations of pressure-velocity(P-V).The braking effects of DC magnetic fields with various configurations were evaluated and compared with those without static magnetic field(SMF).The results show that 0.6 T magnetic field with combination configuration contributes to forming an isokinetic feeding of melt,the re-circulation zone is shifted towards the back wall of reservoir,and the velocity difference on the direction of height decreases from 0.1 m/s to 0.Furthermore,the thickness of solidified skull increases uniformly from 0.45 mm to 1.36 mm on the chilled substrate(belt)near the exit.
文摘针对电动调节阀控制系统在实际生产过程中存在的非线性、多扰动等问题,提出一种基于改进蚁群算法优化单神经元PID(proportional integral derivative)的控制方法并将其应用于阀门开度控制中。该方法利用单神经元网络的自学习和自适应能力,实现PID控制参数的在线整定,并采用改进的蚁群优化算法优化单神经元PID中的学习速率和神经元比例系数,有效克服了单神经元PID中的学习速率和神经元比例系数因经验设定而无法达到预期控制效果的不足。仿真对比结果显示,相比于传统PID、单神经元PID以及基于蚁群优化算法优化单神经元PID 3种控制方法,本文提出的控制方法超调量分别减少了10.2%、6.1%和1.8%,同时调节时间也相应缩短了0.22、0.07、0.03 s,并且表现出更强的自适应和抗干扰能力,能够使阀门开度控制更加稳定可靠。
