To meet the requirements of specifications,intelligent optimization of steel bar blanking can improve resource utilization and promote the intelligent development of sustainable construction.As one of the most importa...To meet the requirements of specifications,intelligent optimization of steel bar blanking can improve resource utilization and promote the intelligent development of sustainable construction.As one of the most important building materials in construction engineering,reinforcing bars(rebar)account for more than 30%of the cost in civil engineering.A significant amount of cutting waste is generated during the construction phase.Excessive cutting waste increases construction costs and generates a considerable amount of CO_(2)emission.This study aimed to develop an optimization algorithm for steel bar blanking that can be used in the intelligent optimization of steel bar engineering to realize sustainable construction.In the proposed algorithm,the integer linear programming algorithm was applied to solve the problem.It was combined with the statistical method,a greedy strategy was introduced,and a method for determining the dynamic critical threshold was developed to ensure the accuracy of large-scale data calculation.The proposed algorithm was verified through a case study;the results confirmed that the rebar loss rate of the proposed method was reduced by 9.124%compared with that of traditional distributed processing of steel bars,reducing CO_(2)emissions and saving construction costs.As the scale of a project increases,the calculation quality of the optimization algorithmfor steel bar blanking proposed also increases,while maintaining high calculation efficiency.When the results of this study are applied in practice,they can be used as a sustainable foundation for building informatization and intelligent development.展开更多
Silicon carbide(SiC) emitter turn-off thyristors(ETOs) are very promising high power capacity semiconductor devices for high voltage and high power density power systems and pulse power applications. However,reports o...Silicon carbide(SiC) emitter turn-off thyristors(ETOs) are very promising high power capacity semiconductor devices for high voltage and high power density power systems and pulse power applications. However,reports on comparison of high voltage SiC GTOs and ETOs in pulse power applications have been rare. In this paper, a comprehensive study on a 6.5 kV SiC GTO and ETO are carried out to demonstrate the superior performance of the SiC ETO over the GTO in pulse power application. A 6.5 kV SiC ETO was designed and tested with a printed circuit board(PCB) integrated gate driver. The forward conduction characteristics of the SiC ETO and GTO in elevated temperatures are measured and compared, showing the excellent temperature coefficient of the SiC ETO's output characteristics. Their turn-off characteristics with resistive load are measured and compared,demonstrating that the SiC ETO has much faster switching speed and smaller turn-off loss. Experimental results demonstrate that the SiC ETO has a better performance, especially with respect to its switching characteristics,making it a very competitive candidate for high power and pulse power applications.展开更多
基金funded by Nature Science Foundation of China(51878556)the Key Scientific Research Projects of Shaanxi Provincial Department of Education(20JY049)+1 种基金Key Research and Development Program of Shaanxi Province(2019TD-014)State Key Laboratory of Rail Transit Engineering Informatization(FSDI)(SKLKZ21-03).
文摘To meet the requirements of specifications,intelligent optimization of steel bar blanking can improve resource utilization and promote the intelligent development of sustainable construction.As one of the most important building materials in construction engineering,reinforcing bars(rebar)account for more than 30%of the cost in civil engineering.A significant amount of cutting waste is generated during the construction phase.Excessive cutting waste increases construction costs and generates a considerable amount of CO_(2)emission.This study aimed to develop an optimization algorithm for steel bar blanking that can be used in the intelligent optimization of steel bar engineering to realize sustainable construction.In the proposed algorithm,the integer linear programming algorithm was applied to solve the problem.It was combined with the statistical method,a greedy strategy was introduced,and a method for determining the dynamic critical threshold was developed to ensure the accuracy of large-scale data calculation.The proposed algorithm was verified through a case study;the results confirmed that the rebar loss rate of the proposed method was reduced by 9.124%compared with that of traditional distributed processing of steel bars,reducing CO_(2)emissions and saving construction costs.As the scale of a project increases,the calculation quality of the optimization algorithmfor steel bar blanking proposed also increases,while maintaining high calculation efficiency.When the results of this study are applied in practice,they can be used as a sustainable foundation for building informatization and intelligent development.
基金Project supported by the National Natural Science Foundation of China(No.51577054)the Science and Technology Major Project of Hunan Province(No.2017GK1020)
文摘Silicon carbide(SiC) emitter turn-off thyristors(ETOs) are very promising high power capacity semiconductor devices for high voltage and high power density power systems and pulse power applications. However,reports on comparison of high voltage SiC GTOs and ETOs in pulse power applications have been rare. In this paper, a comprehensive study on a 6.5 kV SiC GTO and ETO are carried out to demonstrate the superior performance of the SiC ETO over the GTO in pulse power application. A 6.5 kV SiC ETO was designed and tested with a printed circuit board(PCB) integrated gate driver. The forward conduction characteristics of the SiC ETO and GTO in elevated temperatures are measured and compared, showing the excellent temperature coefficient of the SiC ETO's output characteristics. Their turn-off characteristics with resistive load are measured and compared,demonstrating that the SiC ETO has much faster switching speed and smaller turn-off loss. Experimental results demonstrate that the SiC ETO has a better performance, especially with respect to its switching characteristics,making it a very competitive candidate for high power and pulse power applications.
