The particle swarm optimization(PSO)algorithm is an established nature-inspired population-based meta-heuristic that replicates the synchronizing movements of birds and sh.PSO is essentially an unconstrained algorithm...The particle swarm optimization(PSO)algorithm is an established nature-inspired population-based meta-heuristic that replicates the synchronizing movements of birds and sh.PSO is essentially an unconstrained algorithm and requires constraint handling techniques(CHTs)to solve constrained optimization problems(COPs).For this purpose,we integrate two CHTs,the superiority of feasibility(SF)and the violation constraint-handling(VCH),with a PSO.These CHTs distinguish feasible solutions from infeasible ones.Moreover,in SF,the selection of infeasible solutions is based on their degree of constraint violations,whereas in VCH,the number of constraint violations by an infeasible solution is of more importance.Therefore,a PSO is adapted for constrained optimization,yielding two constrained variants,denoted SF-PSO and VCH-PSO.Both SF-PSO and VCH-PSO are evaluated with respect to ve engineering problems:the Himmelblau’s nonlinear optimization,the welded beam design,the spring design,the pressure vessel design,and the three-bar truss design.The simulation results show that both algorithms are consistent in terms of their solutions to these problems,including their different available versions.Comparison of the SF-PSO and the VCHPSO with other existing algorithms on the tested problems shows that the proposed algorithms have lower computational cost in terms of the number of function evaluations used.We also report our disagreement with some unjust comparisons made by other researchers regarding the tested problems and their different variants.展开更多
利用热扩散式边材液流探针和Watch dog 小气候观测仪对延庆县上辛庄水土保持站山杨(Populusdavidiana)边材液流速率及其与环境因子的关系进行了观测研究。结果表明,山杨树干边材液流曲线呈宽峰状,表现出明显的昼夜变化和季节变化规律,...利用热扩散式边材液流探针和Watch dog 小气候观测仪对延庆县上辛庄水土保持站山杨(Populusdavidiana)边材液流速率及其与环境因子的关系进行了观测研究。结果表明,山杨树干边材液流曲线呈宽峰状,表现出明显的昼夜变化和季节变化规律,日出后7:00-8:00时液流开始上升,并于13:00-16:00 时达到峰值,然后迅速下降,19:00时速度变慢,至次日日出之前液流微弱,时断时续;7 月份进入雨季,液流速率提高,8 月份由于持续干旱,有所下降,进入9月份,地形雨增加,含水量湿度提高,液流速率又重新上升,10 月份山杨生长变慢,液流速率明显下降。同时,分析了液流速率的波动规律与主要气象因素波动的相关性。展开更多
目的观察基于微信公众平台的以问题为导向(Problem Based Learning,PBL)教学模式在心血管超声教学中的教学效果。方法选择我校2013级医学影像专业2个班级共60名学生为研究对象,将学生依据班级分为两组即观察组与对照组,分别接受传统方...目的观察基于微信公众平台的以问题为导向(Problem Based Learning,PBL)教学模式在心血管超声教学中的教学效果。方法选择我校2013级医学影像专业2个班级共60名学生为研究对象,将学生依据班级分为两组即观察组与对照组,分别接受传统方式教学和微信平台下的PBL教学方式。课程结束后进行理论考试及问卷调查评估教学效果。结果两组教学方式下的理论考试成绩分别为:对照组(74.6±7.0)分,观察组(77.07±7.06)分,二组差异无统计学意义(P>0.05)。在培养学生学习兴趣、学习能力及团队协作3方面,观察组均优于对照组,教学效果差异有统计学意义(P<0.05)。结论基于微信平台的PBL心血管超声教学效果优于传统授课形式。展开更多
基金The authors thank the Higher Education Commission,Pakistan,for supporting this research under the project NRPU-8925(M.A.J.and H.U.K.),https://www.hec.gowpk/。
文摘The particle swarm optimization(PSO)algorithm is an established nature-inspired population-based meta-heuristic that replicates the synchronizing movements of birds and sh.PSO is essentially an unconstrained algorithm and requires constraint handling techniques(CHTs)to solve constrained optimization problems(COPs).For this purpose,we integrate two CHTs,the superiority of feasibility(SF)and the violation constraint-handling(VCH),with a PSO.These CHTs distinguish feasible solutions from infeasible ones.Moreover,in SF,the selection of infeasible solutions is based on their degree of constraint violations,whereas in VCH,the number of constraint violations by an infeasible solution is of more importance.Therefore,a PSO is adapted for constrained optimization,yielding two constrained variants,denoted SF-PSO and VCH-PSO.Both SF-PSO and VCH-PSO are evaluated with respect to ve engineering problems:the Himmelblau’s nonlinear optimization,the welded beam design,the spring design,the pressure vessel design,and the three-bar truss design.The simulation results show that both algorithms are consistent in terms of their solutions to these problems,including their different available versions.Comparison of the SF-PSO and the VCHPSO with other existing algorithms on the tested problems shows that the proposed algorithms have lower computational cost in terms of the number of function evaluations used.We also report our disagreement with some unjust comparisons made by other researchers regarding the tested problems and their different variants.
文摘目的观察基于微信公众平台的以问题为导向(Problem Based Learning,PBL)教学模式在心血管超声教学中的教学效果。方法选择我校2013级医学影像专业2个班级共60名学生为研究对象,将学生依据班级分为两组即观察组与对照组,分别接受传统方式教学和微信平台下的PBL教学方式。课程结束后进行理论考试及问卷调查评估教学效果。结果两组教学方式下的理论考试成绩分别为:对照组(74.6±7.0)分,观察组(77.07±7.06)分,二组差异无统计学意义(P>0.05)。在培养学生学习兴趣、学习能力及团队协作3方面,观察组均优于对照组,教学效果差异有统计学意义(P<0.05)。结论基于微信平台的PBL心血管超声教学效果优于传统授课形式。
