In view of the problem that it＇s difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex ...In view of the problem that it＇s difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out- in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary condi- tions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the appli- cation of forward design method to high-speed trains.展开更多
In 2005, the classical intersection bodies and L_p intersection bodies were extended. Afterwards, the concept of gen-eral L_p intersection bodies and the generalized intersection bodies was introduced. In this paper, ...In 2005, the classical intersection bodies and L_p intersection bodies were extended. Afterwards, the concept of gen-eral L_p intersection bodies and the generalized intersection bodies was introduced. In this paper, we define the generalized bodies with parameter. Besides, we establish the extremal values for volume, Brunn-Minkowski type inequality for radial combination and L_p harmonic Blaschke combination of this notion.展开更多
The natural convective heat transfer coefficient(hn,c)of the human body is a critical parameter for developing a comprehensive mathematical model of human thermal regulation.As age-dependent personalized thermal comfo...The natural convective heat transfer coefficient(hn,c)of the human body is a critical parameter for developing a comprehensive mathematical model of human thermal regulation.As age-dependent personalized thermal comfort models advance,the hn,c for children and adolescents need increased attention.This study analyzed the hn,c of 36 human models across six age groups using a numerical simulation method validated by experimental data from the thermal manikin.Our results indicate that hn,c on the human body surface decreases progressively with age.The average hn,c of children and adolescents was higher than those of adults(18-70 yr)by 11.66%(4-6 yr),9.23%(7-10 yr),6.67%(11-12 yr),3.89%(13-15 yr),and 1.67%(16-17 yr).The distribution of hn,c across the human body surface is non-uniform,with the highest values observed on the face,hands,feet,and inner arm regions near the torso.For the upper limbs(hands,forearms,upper arms),lower limbs(feet,thighs,calves),and trunk(chest,back,pelvis),hn,c generally decreased with increasing height level.Body segment length directly influences boundary layer development,exhibiting an inverse relationship with hn,c.Based on geometric dimension analysis,a prediction model for local hn,c was developed,incorporating temperature differences and characteristic dimensions.These findings offer a reference for selecting hn,c in developing personalized thermal comfort models.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos51275432,51505390)Sichuan Provincial Application Foundation Projects of China(Grant No.2016JY0098)Independent Research Project of TPL(Grant No.TPL1501)
文摘In view of the problem that it＇s difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out- in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary condi- tions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the appli- cation of forward design method to high-speed trains.
基金Supported by the National Natural Science Foundation of China(11561020,11161019)
文摘In 2005, the classical intersection bodies and L_p intersection bodies were extended. Afterwards, the concept of gen-eral L_p intersection bodies and the generalized intersection bodies was introduced. In this paper, we define the generalized bodies with parameter. Besides, we establish the extremal values for volume, Brunn-Minkowski type inequality for radial combination and L_p harmonic Blaschke combination of this notion.
基金supported by the National Natural Science Foundation of China(No.52278126)the Young Scientists Fund of the National Natural Science Foundation of China(No.52308113)the National Natural Science Foundation of China(No.52408111).
文摘The natural convective heat transfer coefficient(hn,c)of the human body is a critical parameter for developing a comprehensive mathematical model of human thermal regulation.As age-dependent personalized thermal comfort models advance,the hn,c for children and adolescents need increased attention.This study analyzed the hn,c of 36 human models across six age groups using a numerical simulation method validated by experimental data from the thermal manikin.Our results indicate that hn,c on the human body surface decreases progressively with age.The average hn,c of children and adolescents was higher than those of adults(18-70 yr)by 11.66%(4-6 yr),9.23%(7-10 yr),6.67%(11-12 yr),3.89%(13-15 yr),and 1.67%(16-17 yr).The distribution of hn,c across the human body surface is non-uniform,with the highest values observed on the face,hands,feet,and inner arm regions near the torso.For the upper limbs(hands,forearms,upper arms),lower limbs(feet,thighs,calves),and trunk(chest,back,pelvis),hn,c generally decreased with increasing height level.Body segment length directly influences boundary layer development,exhibiting an inverse relationship with hn,c.Based on geometric dimension analysis,a prediction model for local hn,c was developed,incorporating temperature differences and characteristic dimensions.These findings offer a reference for selecting hn,c in developing personalized thermal comfort models.
