The theoretical positioning accuracy of multilateration(MLAT) with the time difference of arrival(TDOA) algorithm is very high. However, there are some problems in practical applications. Here we analyze the location ...The theoretical positioning accuracy of multilateration(MLAT) with the time difference of arrival(TDOA) algorithm is very high. However, there are some problems in practical applications. Here we analyze the location performance of the time sum of arrival(TSOA) algorithm from the root mean square error(RMSE) and geometric dilution of precision(GDOP) in additive white Gaussian noise(AWGN) environment. The TSOA localization model is constructed. Using it, the distribution of location ambiguity region is presented with 4-base stations. And then, the location performance analysis is started from the 4-base stations with calculating the RMSE and GDOP variation. Subsequently, when the location parameters are changed in number of base stations, base station layout and so on, the performance changing patterns of the TSOA location algorithm are shown. So, the TSOA location characteristics and performance are revealed. From the RMSE and GDOP state changing trend, the anti-noise performance and robustness of the TSOA localization algorithm are proved. The TSOA anti-noise performance will be used for reducing the blind-zone and the false location rate of MLAT systems.展开更多
Global Navigation Satellite System(GNSS)-based continuous and accurate train positioning is one of the key technologies for advanced train operations such as train virtual coupling.However,GNSS-based train positioning...Global Navigation Satellite System(GNSS)-based continuous and accurate train positioning is one of the key technologies for advanced train operations such as train virtual coupling.However,GNSS-based train positioning faces significant challenges in real-world scenarios due to environmental complexities and signal interferences.Considering this issue,this paper presents an approach for modeling and performance analysis of GNSS-based train positioning systems using Colored Petri Nets(CPNs).By systematically modeling the GNSS signal reception and processing process,the performance of the positioning system under various environment scenarios is evaluated.The system model integrates three types of interference signals(i.e.,Amplitude Modulation(AM)signals,Frequency Modulation(FM)signals,and pulse signals)while incorporating environmental factors such as terrain obstructions and tunnel shielding.Additionally,the Extended Kalman Filter(EKF)algorithm is employed to process GNSS observation data,providing accurate train position estimations.The simulation results demonstrate that signal interferences and complex environmental conditions significantly affect the GNSS-based positioning accuracy.This study offers a comprehensive framework for evaluating the performance of GNSS-based train positioning systems in different scenarios,highlighting critical factors that influence positioning accuracy and stability.展开更多
Employees’innovative performance determines an organization’s innovation,which critically impacts its structural optimization and sustainability.Applying expectancy theory,we examined how and when the Pygmalion effe...Employees’innovative performance determines an organization’s innovation,which critically impacts its structural optimization and sustainability.Applying expectancy theory,we examined how and when the Pygmalion effect occurs in the relationship between leaders’expectations of innovation and employee innovative behavior.Our sample comprised 201 frontline employees(female=31.84%;mean age=41.48 years,SD=7.97 years)in a Chinese coal enterprise,who completed surveys on innovation expectations of leaders,expected positive performance outcomes,innovative self-efficacy and innovative behavior.The results revealed that employees’expected positive performance outcomes mediated the positive relationship between leaders’innovation expectations and their innovative behavior.Employees’innovative self-efficacy positively moderated the relationship between their expected positive performance outcomes and innovative behavior,with this relationship being stronger for employees with high innovative self-efficacy.Moreover,we validated the moderated mediation model.Findings suggest that leaders can stimulate employee innovative behavior through expressing expectations and they also need to consider the boundary conditions.展开更多
Production Recovery China’s apparel industry saw a sharp increase in the output for the January-September period, according to data collected from statistics-worthy
基金supported by the Joint Civil Aviation Fund of National Natural Science Foundation of China(Nos.U1533108 and U1233112)
文摘The theoretical positioning accuracy of multilateration(MLAT) with the time difference of arrival(TDOA) algorithm is very high. However, there are some problems in practical applications. Here we analyze the location performance of the time sum of arrival(TSOA) algorithm from the root mean square error(RMSE) and geometric dilution of precision(GDOP) in additive white Gaussian noise(AWGN) environment. The TSOA localization model is constructed. Using it, the distribution of location ambiguity region is presented with 4-base stations. And then, the location performance analysis is started from the 4-base stations with calculating the RMSE and GDOP variation. Subsequently, when the location parameters are changed in number of base stations, base station layout and so on, the performance changing patterns of the TSOA location algorithm are shown. So, the TSOA location characteristics and performance are revealed. From the RMSE and GDOP state changing trend, the anti-noise performance and robustness of the TSOA localization algorithm are proved. The TSOA anti-noise performance will be used for reducing the blind-zone and the false location rate of MLAT systems.
基金supported by the National Key Research and Development Program of China(2023YFB3907300)the Fundamental Research Funds for the Central Universities(2024JBMC002)the National Natural Science Foundation of China(T2222015,U2268206).
文摘Global Navigation Satellite System(GNSS)-based continuous and accurate train positioning is one of the key technologies for advanced train operations such as train virtual coupling.However,GNSS-based train positioning faces significant challenges in real-world scenarios due to environmental complexities and signal interferences.Considering this issue,this paper presents an approach for modeling and performance analysis of GNSS-based train positioning systems using Colored Petri Nets(CPNs).By systematically modeling the GNSS signal reception and processing process,the performance of the positioning system under various environment scenarios is evaluated.The system model integrates three types of interference signals(i.e.,Amplitude Modulation(AM)signals,Frequency Modulation(FM)signals,and pulse signals)while incorporating environmental factors such as terrain obstructions and tunnel shielding.Additionally,the Extended Kalman Filter(EKF)algorithm is employed to process GNSS observation data,providing accurate train position estimations.The simulation results demonstrate that signal interferences and complex environmental conditions significantly affect the GNSS-based positioning accuracy.This study offers a comprehensive framework for evaluating the performance of GNSS-based train positioning systems in different scenarios,highlighting critical factors that influence positioning accuracy and stability.
基金funded by“National Natural Science Foundation of China”grant number[71872119]“Shanxi Provincial Government Major Decision-making Consulting Project”grant number[ZB20240114]The APC was funded by“Shanxi Provincial Government Major Decision-making Consulting Project”grant number[ZB20240114].
文摘Employees’innovative performance determines an organization’s innovation,which critically impacts its structural optimization and sustainability.Applying expectancy theory,we examined how and when the Pygmalion effect occurs in the relationship between leaders’expectations of innovation and employee innovative behavior.Our sample comprised 201 frontline employees(female=31.84%;mean age=41.48 years,SD=7.97 years)in a Chinese coal enterprise,who completed surveys on innovation expectations of leaders,expected positive performance outcomes,innovative self-efficacy and innovative behavior.The results revealed that employees’expected positive performance outcomes mediated the positive relationship between leaders’innovation expectations and their innovative behavior.Employees’innovative self-efficacy positively moderated the relationship between their expected positive performance outcomes and innovative behavior,with this relationship being stronger for employees with high innovative self-efficacy.Moreover,we validated the moderated mediation model.Findings suggest that leaders can stimulate employee innovative behavior through expressing expectations and they also need to consider the boundary conditions.
文摘Production Recovery China’s apparel industry saw a sharp increase in the output for the January-September period, according to data collected from statistics-worthy
