Swept-sine integration method for complex amplitude extraction of sweptsine signal

Wei Zheng,Xuli Cui,Huaihai Chen,Ronghui Zheng 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.12

Swept-sine vibration test plays a significant role in product validations. As its basic step, the accuracy and efficiency of complex amplitude (which includes the amplitude and phase information of swept-sine signal) extraction have an important impact on the performance of swept-sine vibration test. In order to improve the efficiency while ensuring its accuracy, a swept-sine integration method is proposed. The proposed swept-sine integration method, which is inspired by tracking filter method and tracking integration method, utilizes a weighted integral process to extract the complex amplitude. A numeral example is presented to compare the performance of the proposed method with several other methods for complex amplitude extraction which are also reviewed in this paper. By comparing the results of the numerical example, some light is shed on the strength of the method proposed. Afterwards, the swept-sine integration method is applied in a real test, further validating the appliance value of this method.

Intranasally Administered Adjunctive Dexmedetomidine Reduces Perioperative Anesthetic Requirements in General Anesthesia

Zheng Chen,Xiang Wu,Li-Hua Hang,Hong Wang,Dong-Hua Shao,Yi-Guo Xu,Wei Cui 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.4

Purpose: Intranasal dexmedetomidine is an effective sedative for premedication and is regularly used to reduce preoperative tension and anxiety in children. This study aimed to assess the effect of intranasally adjunctive dexmedetomidine on perioperativesedative and analgesic requirements in adults. Materials and Methods: Patients were randomly divided into four groups to receive preoperative administration of saline, intranasaldexmedetomidine 1 μg/kg and 2 μg/kg, and intravenous dexmedetomidine 1 μg/kg, respectively. Propofol and remifentanil were target-controlled infused to maintain intraoperative bispectral index at 45–55 and blood pressure at baseline value±20%. Sufentanil was administered to maintain postoperative visual analogue scale ≤3. Perioperative anesthetics requirements were compared using nonparametric tests. Results: Intranasal dexmedetomidine significantly attenuated propofol requirements for anesthesia induction and maintenance in a dose-dependent manner. Patients given intranasal dexmedetomidine 2 μg/kg required less remifentanil for anesthesia maintenance. The first postoperative request for sufentanil analgesia was delayed in patients given intranasal dexmedetomidine 2 μg/kg. The anesthetics-sparing effect of intranasal dexmedetomidine was significantly weaker than intravenous dexmedetomidine at the same dose of 1 μg/kg. The incidences of adverse events, including hemodynamic instability and delayed recovery, were comparablewith and without intranasal dexmedetomidine. Conclusion: Intranasal administration of dexmedetomidine can reduce perioperative anesthetic requirements, and a dose of dexmedetomidine 2 μg/kg produces a better effect in adults. The anesthetics-sparing effect of intranasal dexmedetomidine 1 μg/kg is less than that with the same intravenous dose of dexmedetomidine.

A Speedy Reinforcement Learning-Based Energy Management Strategy for Fuel Cell Hybrid Vehicles Considering Fuel Cell System Lifetime

Wei Li,Jiaye Ye,Yunduan Cui,김남욱,차석원,Chunhua Zheng 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.3

A speedy reinforcement learning (RL)-based energy management strategy (EMS) is proposed for fuel cell hybrid vehicles (FCHVs) in this research, which approaches near-optimal results with a fast convergence rate based on a pre-initialization framework and meanwhile possesses the ability to extend the fuel cell system (FCS) lifetime. In the pre-initialization framework, well-designed power distribution-related rules are used to pre-initialize the Q-table of the RL algorithm to expedite its optimization process. Driving cycles are modeled as Markov processes and the FCS power difference between adjacent moments is used to evaluate the impact on the FCS lifetime in this research. The proposed RL-based EMS is trained on three driving cycles and validated on another driving cycle. Simulation results demonstrate that the average fuel consumption difference between the proposed EMS and the EMS based on dynamic programming is 5.59% on the training driving cycles and the validation driving cycle. Additionally, the power fluctuation on the FCS is reduced by at least 13% using the proposed EMS compared to the conventional RL-based EMS which does not consider the FCS lifetime. This is significantly beneficial for improving the FCS lifetime. Furthermore, compared to the conventional RL-based EMS, the convergence speed of the proposed EMS is increased by 69% with the pre-initialization framework, which presents the potential for realtime applications.

Optimization of Switching Rule and Operating Modes of Hybrid Electric Vehicles

Zheng Wei,C.C. Chan,Cui Shumei 제어로봇시스템학회 2006 제어로봇시스템학회 국제학술대회 논문집 Vol.2006 No.10

Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease

Zheng, You-Kun,Miao, Cui-Ping,Chen, Hua-Hong,Huang, Fang-Fang,Xia, Yu-Mei,Chen, You-Wei,Zhao, Li-Xing The Korean Society of Ginseng 2017 Journal of Ginseng Research Vol.41 No.3

Background: Endophytic fungi play an important role in balancing the ecosystem and boosting host growth. In the present study, we investigated the endophytic fungal diversity of healthy Panax notoginseng and evaluated its potential antimicrobial activity against five major phytopathogens causing root-rot of P. notoginseng. Methods: A culture-dependent technique, combining morphological and molecular methods, was used to analyze endophytic fungal diversity. A double-layer agar technique was used to challenge the phytopathogens of P. notoginseng. Results: A total of 89 fungi were obtained from the roots, stems, leaves, and seeds of P. notoginseng, and 41 isolates representing different morphotypes were selected for taxonomic characterization. The fungal isolates belonged to Ascomycota (96.6%) and Zygomycota (3.4%). All isolates were classified to 23 genera and an unknown taxon belonging to Sordariomycetes. The number of isolates obtained from different tissues ranged from 12 to 42 for leaves and roots, respectively. The selected endophytic fungal isolates were challenged by the root-rot pathogens Alternaria panax, Fusarium oxysporum, Fusarium solani, Phoma herbarum, and Mycocentrospora acerina. Twenty-six of the 41 isolates (63.4%) exhibited activity against at least one of the pathogens tested. Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

Rhizospheric fungi of Panax notoginseng: diversity and antagonism to host phytopathogens

Cui-Ping Miao,Qi-Li Mi,Xin-Guo Qiao,You-Kun Zheng,You-Wei Chen,Li-Hua Xu,Hui-Lin Guan,Li-Xing Zhao 고려인삼학회 2016 Journal of Ginseng Research Vol.40 No.2

Background: Rhizospheric fungi play an essential role in the plantesoil ecosystem, affecting plant growth and health. In this study, we evaluated the fungal diversity in the rhizosphere soil of 2-yr-old healthy Panax notoginseng cultivated in Wenshan, China. Methods: Culture-independent Illumina MiSeq and culture-dependent techniques, combining molecular and morphological characteristics, were used to analyze the rhizospheric fungal diversity. A diffusion test was used to challenge the phytopathogens of P. notoginseng. Results: A total of 16,130 paired-end reads of the nuclear ribosomal internal transcribed spacer 2 were generated and clustered into 860 operational taxonomic units at 97% sequence similarity. All the operational taxonomic units were assigned to five phyla and 79 genera. Zygomycota (46.2%) and Ascomycota (37.8%) were the dominant taxa; Mortierella and unclassified Mortierellales accounted for a large proportion (44.9%) at genus level. The relative abundance of Fusarium and Phoma sequenceswas high, accounting for 12.9% and 5.5%, respectively. In total,113 fungal isolates were isolated from rhizosphere soil. They were assigned to five classes, eight orders (except for an Incertae sedis), 26 genera, and 43 species based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer. Fusarium was the most isolated genus with six species (24 isolates, 21.2%). The abundance of Phoma was also relatively high (8.0%). Thirteen isolates displayed antimicrobial activity against at least one test fungus. Conclusion: Our results suggest that diverse fungi including potential pathogenic ones exist in the rhizosphere soil of 2-yr-old P. notoginseng and that antagonistic isolates may be useful for biological control of pathogens.

Rhizospheric fungi of Panax notoginseng: diversity and antagonism to host phytopathogens

Miao, Cui-Ping,Mi, Qi-Li,Qiao, Xin-Guo,Zheng, You-Kun,Chen, You-Wei,Xu, Li-Hua,Guan, Hui-Lin,Zhao, Li-Xing The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.2

Background: Rhizospheric fungi play an essential role in the plantesoil ecosystem, affecting plant growth and health. In this study, we evaluated the fungal diversity in the rhizosphere soil of 2-yr-old healthy Panax notoginseng cultivated in Wenshan, China. Methods: Culture-independent Illumina MiSeq and culture-dependent techniques, combining molecular and morphological characteristics, were used to analyze the rhizospheric fungal diversity. A diffusion test was used to challenge the phytopathogens of P. notoginseng. Results: A total of 16,130 paired-end reads of the nuclear ribosomal internal transcribed spacer 2 were generated and clustered into 860 operational taxonomic units at 97% sequence similarity. All the operational taxonomic units were assigned to five phyla and 79 genera. Zygomycota (46.2%) and Ascomycota (37.8%) were the dominant taxa; Mortierella and unclassified Mortierellales accounted for a large proportion (44.9%) at genus level. The relative abundance of Fusarium and Phoma sequenceswas high, accounting for 12.9% and 5.5%, respectively. In total,113 fungal isolates were isolated from rhizosphere soil. They were assigned to five classes, eight orders (except for an Incertae sedis), 26 genera, and 43 species based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer. Fusarium was the most isolated genus with six species (24 isolates, 21.2%). The abundance of Phoma was also relatively high (8.0%). Thirteen isolates displayed antimicrobial activity against at least one test fungus. Conclusion: Our results suggest that diverse fungi including potential pathogenic ones exist in the rhizosphere soil of 2-yr-old P. notoginseng and that antagonistic isolates may be useful for biological control of pathogens.

Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease

You-Kun Zheng,Cui-Ping Miao,Hua-Hong Chen,Fang-Fang Huang,Yu-Mei Xia,You-Wei Chen,Li-Xing Zhao 고려인삼학회 2017 Journal of Ginseng Research Vol.41 No.3

Background: Endophytic fungi play an important role in balancing the ecosystem and boosting host growth. In the present study, we investigated the endophytic fungal diversity of healthy Panax notoginseng and evaluated its potential antimicrobial activity against five major phytopathogens causing rootrot of P. notoginseng. Methods: A culture-dependent technique, combining morphological and molecular methods, was used to analyze endophytic fungal diversity. A double-layer agar technique was used to challenge the phytopathogens of P. notoginseng. Results: A total of 89 fungi were obtained from the roots, stems, leaves, and seeds of P. notoginseng, and 41 isolates representing different morphotypes were selected for taxonomic characterization. The fungal isolates belonged to Ascomycota (96.6%) and Zygomycota (3.4%). All isolates were classified to 23 genera and an unknown taxon belonging to Sordariomycetes. The number of isolates obtained from different tissues ranged from 12 to 42 for leaves and roots, respectively. The selected endophytic fungal isolates were challenged by the root-rot pathogens Alternaria panax, Fusarium oxysporum, Fusarium solani, Phoma herbarum, and Mycocentrospora acerina. Twenty-six of the 41 isolates (63.4%) exhibited activity against at least one of the pathogens tested. Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

THE MAGNETIC SEPARATION OF Nd - Fe - B POWDERS

Li-Ya Cui,Da-Li Zheng,Jing-Han Zhu,Wei-Hong Zhao,Shu-Lin Ding 한국자기학회 1995 韓國磁氣學會誌 Vol.5 No.5

The magnetic separation of Nd-Fe-B powders prepared by melt-spun and HDDR processes was investigated. The experiments show that the ununiform melt-spun powders can be separated into various standards by means of magnetic separation method. The magnetic powders with higher properties were obtained by the use of suitable separating field. For example, the properties of ununiform melt-spun powders are Br=7.95 kG, iHc=9.93 kOe and (BH)max=10.2 MGOe before separating. Through separating in different magnetic fields, the powders obtained with a separating field of 780 Oe has the optimum properties of Br=7.7 kG, iHc=11.0 kOe and (BH)max=15.3 MGOe. The magnetic properties of the HDDR magnetic powder are hardly separated by the magnetic separation method.

Loss Analysis and Soft-Switching Behavior of Flyback-Forward High Gain DC/DC Converters with a GaN FET

Li, Yan,Zheng, Trillion Q.,Zhang, Yajing,Cui, Meiting,Han, Yang,Dou, Wei The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

Compared with Si MOSFETs, the GaN FET has many advantages in a wide band gap, high saturation drift velocity, high critical breakdown field, etc. This paper compares the electrical properties of GaN FETs and Si MOSFETs. The soft-switching condition and power loss analysis in a flyback-forward high gain DC/DC converter with a GaN FET is presented in detail. In addition, a comparison between GaN diodes and Si diodes is made. Finally, a 200W GaN FET based flyback-forward high gain DC/DC converter is established, and experimental results verify that the GaN FET is superior to the Si MOSFET in terms of switching characteristics and efficiency. They also show that the GaN diode is better than the Si diode when it comes to reverse recovery characteristics.