认识染色体的三维空间结构对于理解细胞核内基因组的表达、调控等具有重要作用.针对Hi-C数据稀疏和含有噪声的特点,提出了基于流形优化(manifold based optimization,MBO)与参数优化相结合的染色体三维结构预测方法——变参数的基于流...认识染色体的三维空间结构对于理解细胞核内基因组的表达、调控等具有重要作用.针对Hi-C数据稀疏和含有噪声的特点,提出了基于流形优化(manifold based optimization,MBO)与参数优化相结合的染色体三维结构预测方法——变参数的基于流形优化的算法(variable-parameter MBO,VMBO).通过黄金分割算法迭代优化转换参数,将染色体片段间的接触频率转换为空间距离值;然后用MBO算法重构染色体的三维平均结构(consensus structures).在实验部分用模拟数据集和真实的Hi-C数据集进行三维结构预测,预测结果的均方根误差(root mean squared deviation,RMSD)和距离的斯皮尔曼相关系数(distance Spearman correlation coefficient,d SCC)说明了VMBO算法的有效性和鲁棒性.展开更多
Taking the ratio of heat transfer area to net power and heat recovery efficiency into account, a multi-objective mathematical model was developed for organic Rankine cycle （ORC）. Working fluids considered were R123,...Taking the ratio of heat transfer area to net power and heat recovery efficiency into account, a multi-objective mathematical model was developed for organic Rankine cycle （ORC）. Working fluids considered were R123, R134a, R141b, R227ea and R245fa. Under the given conditions, the parameters including evaporating and condensing pressures, working fluid and cooling water velocities were optimized by simulated annealing algorithm. The results show that the optimal evaporating pressure increases with the heat source temperature increasing. Compared with other working fluids, R123 is the best choice for the temperature range of 100--180℃ and R141 b shows better performance when the temperature is higher than 180 ℃. Economic characteristic of system decreases rapidly with the decrease of heat source temperature. ORC system is uneconomical for the heat source temperature lower than 100℃.展开更多
Aiming at dealing with the difficulty for traditional emergency rescue vehicle(ECV)to enter into limited rescue scenes,the electro-hydraulic steer-by-wire(SBW)system is introduced to achieve the multi-mode steering of...Aiming at dealing with the difficulty for traditional emergency rescue vehicle(ECV)to enter into limited rescue scenes,the electro-hydraulic steer-by-wire(SBW)system is introduced to achieve the multi-mode steering of the ECV.The overall structure and mathematical model of the SBW system are described at length.The fractional order proportional-integral-derivative(FOPID)controller based on fractional calculus theory is designed to control the steering cylinder’s movement in SBW system.The anti-windup problem is considered in the FOPID controller design to reduce the bad influence of saturation.Five parameters of the FOPID controller are optimized using the genetic algorithm by maximizing the fitness function which involves integral of time by absolute value error(ITAE),peak overshoot,as well as settling time.The time-domain simulations are implemented to identify the performance of the raised FOPID controller.The simulation results indicate the presented FOPID controller possesses more effective control properties than classical proportional-integral-derivative(PID)controller on the part of transient response,tracking capability and robustness.展开更多
We introduce the artificial fish swarm algorithm for heading motion model identification and control parameter optimization problems for the“Ocean Rambler”unmanned wave glider(UWG).First,under certain assumptions,th...We introduce the artificial fish swarm algorithm for heading motion model identification and control parameter optimization problems for the“Ocean Rambler”unmanned wave glider(UWG).First,under certain assumptions,the rigid-flexible multi-body system of the UWG was simplified as a rigid system composed of“thruster+float body”,based on which a planar motion model of the UWG was established.Second,we obtained the model parameters using an empirical method combined with parameter identification,which means that some parameters were estimated by the empirical method.In view of the specificity and importance of the heading control,heading model parameters were identified through the artificial fish swarm algorithm based on tank test data,so that we could take full advantage of the limited trial data to factually describe the dynamic characteristics of the system.Based on the established heading motion model,parameters of the heading S-surface controller were optimized using the artificial fish swarm algorithm.Heading motion comparison and maritime control experiments of the“Ocean Rambler”UWG were completed.Tank test results show high precision of heading motion prediction including heading angle and yawing angular velocity.The UWG shows good control performance in tank tests and sea trials.The efficiency of the proposed method is verified.展开更多
电网停电计划的排期结果关系到电网安全稳定运行和检修工作的开展,是电网运行方式业务的重要组成。目前,已有计划排期方法缺乏对计划间存在冲突这一场景的考虑,且算法效率较低,难以满足停电计划排期的实际需求。为此,该文以工作量不均...电网停电计划的排期结果关系到电网安全稳定运行和检修工作的开展,是电网运行方式业务的重要组成。目前,已有计划排期方法缺乏对计划间存在冲突这一场景的考虑,且算法效率较低,难以满足停电计划排期的实际需求。为此,该文以工作量不均衡度、停电计划时间调整量、停电经济成本为目标,涵盖计划关联关系判别和优先级排序等过程,建立了考虑冲突的电网停电计划优化求解模型。在此基础上,通过对NSGA II算法(the second generation of non-dominated sorting genetic algorithm,NSGAII)进行性能改进,提出了基于约束的自适应NSGAII算法(constraint-basedadaptive NSGAII,CA-NSGAII),并将其用于模型求解。最后,在IEEE-300输电系统模型中模拟了月停电计划排期过程,验证了该文所提模型与实际情况更为贴近,所提求解算法更加准确高效。展开更多
文摘针对水文模拟中参数优化问题,提出一整套合理的并行参数优化算法。改进优化算法中的相关算子,提高算法的搜索效率;结合遗传算法、模拟退火算法、粒子群算法和差分进化算法4种算法,进一步提高算法的搜索效率;使用基于MPI(message passing interface)通信子空间的双层主-从并行框架完成实现,减少算法的运行时间。通过调用SWAT(soil and water assessment tool)、HIMS(hydro informatic modeling system)两大模型的参数优化过程进行实验,实验结果表明,该方法能够有效提高Nash-Suttcliffe系数和运行速度,提升了水文模拟中参数优化过程的效率。
基金Project(2009GK2009) supported by Science and Technology Department Funds of Hunan Province,ChinaProject(08C26224302178) supported by Innovation Fund for Technology Based Firms of China
文摘Taking the ratio of heat transfer area to net power and heat recovery efficiency into account, a multi-objective mathematical model was developed for organic Rankine cycle （ORC）. Working fluids considered were R123, R134a, R141b, R227ea and R245fa. Under the given conditions, the parameters including evaporating and condensing pressures, working fluid and cooling water velocities were optimized by simulated annealing algorithm. The results show that the optimal evaporating pressure increases with the heat source temperature increasing. Compared with other working fluids, R123 is the best choice for the temperature range of 100--180℃ and R141 b shows better performance when the temperature is higher than 180 ℃. Economic characteristic of system decreases rapidly with the decrease of heat source temperature. ORC system is uneconomical for the heat source temperature lower than 100℃.
基金Project(2016YFC0802904)supported by the National Key Research and Development Program of China
文摘Aiming at dealing with the difficulty for traditional emergency rescue vehicle(ECV)to enter into limited rescue scenes,the electro-hydraulic steer-by-wire(SBW)system is introduced to achieve the multi-mode steering of the ECV.The overall structure and mathematical model of the SBW system are described at length.The fractional order proportional-integral-derivative(FOPID)controller based on fractional calculus theory is designed to control the steering cylinder’s movement in SBW system.The anti-windup problem is considered in the FOPID controller design to reduce the bad influence of saturation.Five parameters of the FOPID controller are optimized using the genetic algorithm by maximizing the fitness function which involves integral of time by absolute value error(ITAE),peak overshoot,as well as settling time.The time-domain simulations are implemented to identify the performance of the raised FOPID controller.The simulation results indicate the presented FOPID controller possesses more effective control properties than classical proportional-integral-derivative(PID)controller on the part of transient response,tracking capability and robustness.
基金Project(51779052)supported by the National Natural Science Foundation of ChinaProject(QC2016062)supported by the Natural Science Foundation of Heilongjiang Province,China+2 种基金Project(614221503091701)supported by the Research Fund from Science and Technology on Underwater Vehicle Laboratory,ChinaProject(LBH-Q17046)supported by the Heilongjiang Postdoctoral Funds for Scientific Research Initiation,ChinaProject(HEUCFP201741)supported by the Fundamental Research Funds for the Central Universities,China
文摘We introduce the artificial fish swarm algorithm for heading motion model identification and control parameter optimization problems for the“Ocean Rambler”unmanned wave glider(UWG).First,under certain assumptions,the rigid-flexible multi-body system of the UWG was simplified as a rigid system composed of“thruster+float body”,based on which a planar motion model of the UWG was established.Second,we obtained the model parameters using an empirical method combined with parameter identification,which means that some parameters were estimated by the empirical method.In view of the specificity and importance of the heading control,heading model parameters were identified through the artificial fish swarm algorithm based on tank test data,so that we could take full advantage of the limited trial data to factually describe the dynamic characteristics of the system.Based on the established heading motion model,parameters of the heading S-surface controller were optimized using the artificial fish swarm algorithm.Heading motion comparison and maritime control experiments of the“Ocean Rambler”UWG were completed.Tank test results show high precision of heading motion prediction including heading angle and yawing angular velocity.The UWG shows good control performance in tank tests and sea trials.The efficiency of the proposed method is verified.
文摘电网停电计划的排期结果关系到电网安全稳定运行和检修工作的开展,是电网运行方式业务的重要组成。目前,已有计划排期方法缺乏对计划间存在冲突这一场景的考虑,且算法效率较低,难以满足停电计划排期的实际需求。为此,该文以工作量不均衡度、停电计划时间调整量、停电经济成本为目标,涵盖计划关联关系判别和优先级排序等过程,建立了考虑冲突的电网停电计划优化求解模型。在此基础上,通过对NSGA II算法(the second generation of non-dominated sorting genetic algorithm,NSGAII)进行性能改进,提出了基于约束的自适应NSGAII算法(constraint-basedadaptive NSGAII,CA-NSGAII),并将其用于模型求解。最后,在IEEE-300输电系统模型中模拟了月停电计划排期过程,验证了该文所提模型与实际情况更为贴近,所提求解算法更加准确高效。
