This article presents a modeling and simulation method for transient thermal analyses of integrated circuits(ICs)using the original and voltage-in-current(VinC)latency insertion method(LIM).LIM-based algorithms are a ...This article presents a modeling and simulation method for transient thermal analyses of integrated circuits(ICs)using the original and voltage-in-current(VinC)latency insertion method(LIM).LIM-based algorithms are a set of fast transient simulation methods that solve electrical circuits in a leapfrog updating manner without relying on large matrix operations used in conventional Simulation Program with Integrated Circuit Emphasis(SPICE)-based methods which can significantly slow down the solution process.The conversion from the thermal to electrical model is performed first by using the analogy between heat and electrical conduction.Since electrical inductance has no thermal equivalence,a modified VinC LIM formulation is presented which removes the requirement of the insertion of fictitious inductors.Numerical examples are presented,which show that the modified VinC LIM formulation outperforms the basic LIM formulation,in terms of both stability and accuracy in the transient thermal simulation of ICs.展开更多
The mechanization of ship-shaped transplanting is currently an urgent problem that should be solved.The movement trajectory of the transplanting mechanism is the key technology to perform ship-shaped transplanting.In ...The mechanization of ship-shaped transplanting is currently an urgent problem that should be solved.The movement trajectory of the transplanting mechanism is the key technology to perform ship-shaped transplanting.In this study,a ship-shaped transplanting trajectory was built and a mathematical model of a four-link transplanting mechanism was developed based on the requirements of the sweet potato transplanting agronomic technology.The particle swarm optimization algorithm was used,with the length of the four-bar mechanism and the installation angle of the fixed bar serving as the variables to optimize.The objective was to minimize the deviation of the ship-shaped transplanting trajectory,yielding an iterative optimization solution.The MATLAB simulation results showed that the penalty factors of different proportions in the adaptive particle swarm optimization algorithm affected the transplanting trajectory.The optimal penalty factor parameters areα=0.6,β=0.4.They ensure that the transplanting trajectory fulfills the agronomic requirements,and limit the deviation in the return trajectory of the mechanism.The sizes of the optimized four-bar mechanism were 110,312,245,160,360,and,160 mm.The determined installation angle was 100°.The results of the field experiments demonstrated that the optimized four-bar transplanting mechanism can better fulfill the agronomic technical requirements of sweet potato ship-shaped transplanting.For a transplanting speed of 0.2 m/s,the average qualified rates of insertion depth,insertion length,and tail height were equal to 94.00%,93.83%,and 91.67%.The results obtained in this study provide a theoretical basis and technical support for studying and developing sweet potato ship-shaped transplanting machinery.展开更多
基金This work was supported by the Fundamental Research Grant Scheme(FRGS)sponsored by the Ministry of Higher Education,Malaysia under Grant No.FRGS/1/2020/TK0/USM/02/7.
文摘This article presents a modeling and simulation method for transient thermal analyses of integrated circuits(ICs)using the original and voltage-in-current(VinC)latency insertion method(LIM).LIM-based algorithms are a set of fast transient simulation methods that solve electrical circuits in a leapfrog updating manner without relying on large matrix operations used in conventional Simulation Program with Integrated Circuit Emphasis(SPICE)-based methods which can significantly slow down the solution process.The conversion from the thermal to electrical model is performed first by using the analogy between heat and electrical conduction.Since electrical inductance has no thermal equivalence,a modified VinC LIM formulation is presented which removes the requirement of the insertion of fictitious inductors.Numerical examples are presented,which show that the modified VinC LIM formulation outperforms the basic LIM formulation,in terms of both stability and accuracy in the transient thermal simulation of ICs.
基金financially supported by Scientific Research Project of Colleges and Universities in Anhui Province(Grant No.2023AH052645)West Anhui University 2022 High-Level Talent Research Project(Grant No.00701092347)the Fund of Traditional Chinese Medicine Institute of Anhui Dabie Mountain(TCMADM-2024-16).
文摘The mechanization of ship-shaped transplanting is currently an urgent problem that should be solved.The movement trajectory of the transplanting mechanism is the key technology to perform ship-shaped transplanting.In this study,a ship-shaped transplanting trajectory was built and a mathematical model of a four-link transplanting mechanism was developed based on the requirements of the sweet potato transplanting agronomic technology.The particle swarm optimization algorithm was used,with the length of the four-bar mechanism and the installation angle of the fixed bar serving as the variables to optimize.The objective was to minimize the deviation of the ship-shaped transplanting trajectory,yielding an iterative optimization solution.The MATLAB simulation results showed that the penalty factors of different proportions in the adaptive particle swarm optimization algorithm affected the transplanting trajectory.The optimal penalty factor parameters areα=0.6,β=0.4.They ensure that the transplanting trajectory fulfills the agronomic requirements,and limit the deviation in the return trajectory of the mechanism.The sizes of the optimized four-bar mechanism were 110,312,245,160,360,and,160 mm.The determined installation angle was 100°.The results of the field experiments demonstrated that the optimized four-bar transplanting mechanism can better fulfill the agronomic technical requirements of sweet potato ship-shaped transplanting.For a transplanting speed of 0.2 m/s,the average qualified rates of insertion depth,insertion length,and tail height were equal to 94.00%,93.83%,and 91.67%.The results obtained in this study provide a theoretical basis and technical support for studying and developing sweet potato ship-shaped transplanting machinery.