Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condi...Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condition that affects its torque and speed range. The aim of the study is to obtain the optimum differential gear ratio with fast and accurate optimization calculation without affecting drivability characteristics of the vehicle according to certain driving cycles that represent the new working conditions of the truck. The study is carried on a mining dump truck YT3621 with 9 for- ward shift manual transmission. Two loading conditions, no load and 40 t, and four on road real driving cycles have been discussed. The truck powertrain is modeled using GT-drive, and DOE -post processing tool of the GT-suite is used for DOE analysis and genetic algorithm optimization.展开更多
The problem of preserving fidelity in numerical computation of nonlinear or-dinary differential equations is studied in terms of preserving local differential structure and approximating global integration structure o...The problem of preserving fidelity in numerical computation of nonlinear or-dinary differential equations is studied in terms of preserving local differential structure and approximating global integration structure of the dynamical system. The ordinary differen-tial equations are lifted to the corresponding partial differential equations in the framework of algebraic dynamics,and a new algorithm——algebraic dynamics algorithm is proposed based on the exact analytical solutions of the ordinary differential equations by the alge-braic dynamics method. In the new algorithm,the time evolution of the ordinary differential system is described locally by the time translation operator and globally by the time evo-lution operator. The exact analytical piece-like solution of the ordinary differential equa-tions is expressd in terms of Taylor series with a local convergent radius,and its finite order truncation leads to the new numerical algorithm with a controllable precision better than Runge Kutta Algorithm and Symplectic Geometric Algorithm.展开更多
This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An...This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.展开更多
提出一种圆形口径矩形网格平面阵列和圆形口径三角网格平面阵列的波束优化方法.该方法基于差分进化算法优化阵列的幅度加权,以得到满足指标的阵列远场方向图.将阵列的幅度加权矩阵视为水平向和垂直向2个幅度加权矢量的乘积,相应地将优...提出一种圆形口径矩形网格平面阵列和圆形口径三角网格平面阵列的波束优化方法.该方法基于差分进化算法优化阵列的幅度加权,以得到满足指标的阵列远场方向图.将阵列的幅度加权矩阵视为水平向和垂直向2个幅度加权矢量的乘积,相应地将优化矢量的长度由M×N数量级降低为M+N数量级;限定幅度加权在水平向和垂直向基于中心对称,大幅降低了优化迭代次数;采用插值算法,基于优化矢量得到适用于圆形口径阵列的幅度加权矩阵.数值仿真实验结果表明,该方法能快速高效地综合出指标满足要求的阵列方向图,副瓣电平可以达到-35 d B,零陷电平可以达到-60 d B.展开更多
文摘Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condition that affects its torque and speed range. The aim of the study is to obtain the optimum differential gear ratio with fast and accurate optimization calculation without affecting drivability characteristics of the vehicle according to certain driving cycles that represent the new working conditions of the truck. The study is carried on a mining dump truck YT3621 with 9 for- ward shift manual transmission. Two loading conditions, no load and 40 t, and four on road real driving cycles have been discussed. The truck powertrain is modeled using GT-drive, and DOE -post processing tool of the GT-suite is used for DOE analysis and genetic algorithm optimization.
基金This work was supported in part by the National Natural Science Foundation of China (Grant Nos.10375039 and 90503008)the Doctoral Program Foundation from the Ministry of Education of China,and the Center of Nuclear Physics of HIRFL of China.
文摘The problem of preserving fidelity in numerical computation of nonlinear or-dinary differential equations is studied in terms of preserving local differential structure and approximating global integration structure of the dynamical system. The ordinary differen-tial equations are lifted to the corresponding partial differential equations in the framework of algebraic dynamics,and a new algorithm——algebraic dynamics algorithm is proposed based on the exact analytical solutions of the ordinary differential equations by the alge-braic dynamics method. In the new algorithm,the time evolution of the ordinary differential system is described locally by the time translation operator and globally by the time evo-lution operator. The exact analytical piece-like solution of the ordinary differential equa-tions is expressd in terms of Taylor series with a local convergent radius,and its finite order truncation leads to the new numerical algorithm with a controllable precision better than Runge Kutta Algorithm and Symplectic Geometric Algorithm.
文摘This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.
文摘提出一种圆形口径矩形网格平面阵列和圆形口径三角网格平面阵列的波束优化方法.该方法基于差分进化算法优化阵列的幅度加权,以得到满足指标的阵列远场方向图.将阵列的幅度加权矩阵视为水平向和垂直向2个幅度加权矢量的乘积,相应地将优化矢量的长度由M×N数量级降低为M+N数量级;限定幅度加权在水平向和垂直向基于中心对称,大幅降低了优化迭代次数;采用插值算法,基于优化矢量得到适用于圆形口径阵列的幅度加权矩阵.数值仿真实验结果表明,该方法能快速高效地综合出指标满足要求的阵列方向图,副瓣电平可以达到-35 d B,零陷电平可以达到-60 d B.
