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Wyszukujesz frazę "Li, Hao" wg kryterium: Autor


Wyświetlanie 1-6 z 6
Tytuł:
Dynamic characteristics of underframe semi-active inerter-based suspended device for high-speed train based on LQR control
Autorzy:
Wang, Yong
Li, Hao-Xuan
Meng, Hao-Dong
Wang, Yang
Powiązania:
https://bibliotekanauki.pl/articles/2173695.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dynamic characteristics
high-speed train
inerter-based suspended device
LQR control
Sperling index
charakterystyka dynamiczna
pociąg dużych prędkości
aktywne zawieszenie na bazie inertera
kontrola LQR
indeks Sperlinga
Opis:
The underframe passive inerter-based suspended device, based on the inerter-spring-damper vibration attenuation structure, could improve the dynamic performance of the train body, but its parameters are fixed and cannot meet the dynamic performance requirements under different operating conditions. Therefore, a semi-active inerter-based suspended device based on the linear quadratic regulator (LQR) control strategy is proposed to further enhance the dynamic performance. The rigid-flexible coupling vertical dynamic model of the train body and an underframe semi-active inerter-based suspended device are established. The structural parameters of the semi-active inerter-based suspended device are adjusted using LQR control strategy. Dynamic response of the system is obtained using the virtual excitation method. The dynamic characteristic of the system is evaluated using the Sperling index and compared with those of the passive and semi-active traditional suspended devices as well as the passive inerter-based suspended devices. The vertical vibration acceleration of the train body and Sperling index using the semi-active inerter-based suspended device is the smallest among the four suspended devices, which denotes the advantages of using the inerter and LQR control strategy. The semi-active inerter-based suspended device could decrease the vertical vibration acceleration of the train body and further suppress its elastic vibration in the lower frequency band, more effectively than the other three suspended devices. Overall, the semi-active inerter-based suspended device could significantly reduce elastic vibration of the train body and improve its dynamical performance.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 4; art. no. e141722
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comprehensive Analysis of Metal Deformation Law Based on Numerical Simulation of Cold Rolling Process
Autorzy:
Yan, Zhu-Wen
Wang, Bao-Sheng
Bu, He-Nan
Li, Hao
Hong, Lei
Zhang, Dian-Hua
Powiązania:
https://bibliotekanauki.pl/articles/2106570.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
3D elastic-plastic FEM
work roll deflection
lateral thickness
flatness regulation effect
rolling pressure
Opis:
Through taking the cold rolling process as the research object, the three-dimensional finite element model of the strip rolling process is established by using ANSYS/LS-DYNA software. The actual rolling product data has strong consistency with the finite element simulation results. The rolling process is dynamically simulated, and the distribution curves of important rolling parameters such as equivalent stress, control efficiency coefficient, transverse rolling pressure, lateral thickness and work roll deflection is obtained. Based on summarizing the influence of rolling parameters on rolling deformation, the research results of this paper can play an important role in the actual rolling process control. The research results have certain guiding significance for the development and optimization of the rolling control system.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 2; 623--635
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Continuous Growth of Bulk Si by Temperature Gradient Zone Melting Method
Autorzy:
Li, Jiayan
Wang, Liang
Hao, Jianjie
Ni, Ping
Tan, Yi
Powiązania:
https://bibliotekanauki.pl/articles/356541.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bulk Si
TGZM
Si-Al alloy
growth rate
impurities
Opis:
Temperature gradient zone melting (TGZM) method was used to obtain bulk Si continuously for the efficient separation and purification of primary Si from the Si-Al alloy in this work. The effects of alloy thickness, temperature gradient and holding time in TGZM purification technology were investigated. Finally, the continuous growth of bulk Si without eutectic inclusions was obtained. The results showed that the growth rate of bulk Si was independent of the liquid zone thickness. When the temperature gradient was changed from 2.48 K/mm to 3.97 K/mm, the growth rate of bulk Si was enhanced from 7.9×10-5 mm/s to 2.47×10-4 mm/s, which was increased by about 3 times. The bulk Si could grow continuously and the growth rate was decreased with the increase of holding time from 1 h to 5 h. Meanwhile, low refining temperature was beneficial to the removal of impurities. With a precipitation temperature of 1460 K and a temperature gradient of 2.48 K/mm, the removal rates of Fe, P and B were 99.8%, 94.0% and 63.6%, respectively.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 1; 271-278
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter identification approach using improved teaching and learning based optimization for hub motor considering temperature rise
Autorzy:
Li, Yong
Wang, Yuan
Zhang, Taohua
Hu, Han
Wu, Hao
Powiązania:
https://bibliotekanauki.pl/articles/2203368.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
parameters identification
teaching–learning-based optimization
hub motor
temperature rise
Opis:
Temperature rise of the hub motor in distributed drive electric vehicles (DDEVs) under long-time and overload operating conditions brings parameter drift and degrades the performance of the motor. A novel online parameter identification method based on improved teaching-learning-based optimization (ITLBO) is proposed to estimate the stator resistance, -axis inductance, -axis inductance, and flux linkage of the hub motor with respect to temperature rise. The effect of temperature rise on the stator resistance, -axis inductance, -axis inductance, and magnetic flux linkage is analysed. The hub motor parameters are identified offline. The proposed ITLBO algorithm is introduced to estimate the parameters online. The Gaussian perturbation function is employed to optimize the TLBO algorithm and improve the identification speed and accuracy. The mechanisms of group learning and low-ranking elimination are established. After that, the proposed ITLBO algorithm for parameter identification is employed to identify the hub motor parameters online on the test bench. Compared with other parameter identification algorithms, both simulation and experimental results show the proposed ITLBO algorithm has rapid convergence and a higher convergence precision, by which the robustness of the algorithm is effectively verified.
Źródło:
Metrology and Measurement Systems; 2023, 30, 1; 99--115
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of PM2.5 hourly concentrations in Beijing based on machine learning algorithm and ground-based LiDAR
Autorzy:
Fang, Zhiyuan
Yang, Hao
Li, Cheng
Cheng, Liangliang
Zhao, Ming
Xie, Chenbo
Powiązania:
https://bibliotekanauki.pl/articles/2073773.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PM2.5
LiDAR
machine learning
air pollution monitoring
Opis:
The prediction of PM2.5 is important for environmental forecasting and air pollution control. In this study, four machine learning methods, ground-based LiDAR data and meteorological data were used to predict the ground-level PM2.5 concentrations in Beijing. Among the four methods, the random forest (RF) method was the most effective in predicting ground-level PM2.5 concentrations. Compared with BP neural network, support vector machine (SVM), and various linear fitting methods, the accuracy of the RF method was superior by 10%. The method can describe the spatial and temporal variation in PM2.5 concentrations under different meteorological conditions, with low root mean square error (RMSE) and mean square deviation (MD), and the consistency index (IA) reached 99.69%. Under different weather conditions, the hourly variation in PM2.5 concentrations has a good descriptive ability. In this paper, we analyzed the weights of input variables in the RF method, constructed a pollution case to correspond to the relationship between input variables and PM2.5, and analyzed the sources of pollutants via HYSPLIT backward trajectory. This method can study the interaction between PM2.5 and air pollution variables, and provide new ideas for preventing and forecasting air pollution.
Źródło:
Archives of Environmental Protection; 2021, 47, 3; 98--107
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
RFID tag group recognition based on motion blur estimation and YOLOv2 improved by Gaussian algorithm
Autorzy:
Li, Lin
Yu, Xiao-Lei
Liu, Zhen-Lu
Zhao, Zhi-Min
Zhang, Ke
Zhou, Shan-Hao
Powiązania:
https://bibliotekanauki.pl/articles/2051852.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
RFID
YOLOv2
neural network
GRNN
Opis:
Effective recognition of tags in the dynamic measurement system would significantly improve the reading performance of the tag group, but the blurred outline and appearance of tag images captured in motion seriously limit the effectiveness of the existing tag group recognition. Thus, this paper proposes passive tag group recognition in the dynamic environment based on motion blur estimation and improved YOLOv2. Firstly, blur angles are estimated with a Gabor filter, and blur lengths are estimated through nonlinear modelling of a Generalized Regression Neural Network (GRNN). Secondly, tag recognition based on YOLOv2 improved by a Gaussian algorithm is proposed. The features of the tag group are analyzed by the Gaussian algorithm, the region of interest of the dynamic tag is effectively framed, and the tag foreground is extracted; Secondly, the data set of tag groups are trained by the end-to-end YOLOv2 algorithm for secondary screening and recognition, and finally the specific locations of tags are framed to meet the effective identification of tag groups in different scenes. A considerable number of experiments illustrate that the fusion algorithm can significantly improve recognition accuracy. Combined with the reading distance, the research presented in this paper can more accurately optimize the three-dimensional structure of the tag group, improve the reading performance of the tag group, and avoid the interference and collision of tags in the communication channel. Compared with the previous template matching algorithm, the tag group recognition ability put forward in this paper is improved by at least 13.9%, and its reading performance is improved by at least 6.2% as shown in many experiments.
Źródło:
Metrology and Measurement Systems; 2022, 29, 1; 53-74
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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