Pulse-width Adjustment Strategy for Improving the Dynamic Inductor Current Response Performance of a Novel Bidirectional DC–DC Boost Converter

Mingyue Li,Peimin Yan 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1

This paper presents a pulse-width adjustment (PWA) strategy for a novel bidirectional DC–DC boost converter to improve the performance of the dynamic inductor current response. This novel converter consists of three main components: a full-bridge converter (FBC), a high-frequency isolated transformer with large leakage inductance, and a three-level voltage-doubler rectifier (VDR). A number of scholars have analyzed the principles, such as the soft-switching performance and high-efficiency characteristic, of this converter based on pulse-width modulation plus phase-shift (PPS) control. It turns out that this converter is suitable for energy storage applications and exhibits good performance. However, the dynamic inductor current response processes of control variable adjustment is not analyzed in this converter. In fact, dc component may occur in the inductor current during its dynamic response process, which can influence the stability and reliability of the converter system. The dynamic responses under different operating modes of a conventional feedforward control are discussed in this paper. And a PWA strategy is proposed to enhance the dynamic inductor current response performance of the converter. This paper gives a detailed design and implementation of the PWA strategy. The proposed strategy is verified through a series of simulation and experimental results.

Preparation of N-Doped Graphene by Hydrothermal Method and Interpretation of N-Doped Mechanism

Yan Shang,Huizhu Xu,Mingyue Li,Guiling Zhang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.2

Nitrogen-doped graphene (NG) was generated by hydrothermal method, using GO as the raw material and formamide as the reducing-doping source. The composite material was characterized by Fourier transform infrared (FTIR) spectrum, X-ray diffraction (XRD) spectrum, X-ray photoelectron spectroscopy (XPS). The results showed that Nitrogen was successfully doped in the graphene. Through regulating the reaction temperature, time and the ratio of graphite oxide and formamide, the different nitrogen contents were obtained, the highest nitrogen content was 5.67%. NG was also synthesized by urea or ammonia, characterizing by XPS. The characterization results showed that for taking urea and ammonia as nitrogen source, pyrrolic-N was the main form of nitrogen existing, taking formamide as a nitrogen, pyridinic-N was the main form of nitrogen existing. Based on these experimental results by different nitrogen source, the N-doped graphene mechanism was interpreted.

Design of a Fresnel Lens for a Solar End-pumped Solid-state Laser

Mingyu Ou,Pian Hu,Lanling Lan,Yan Liu,Jun Zhou,Xiaotao Shi 한국광학회 2020 Current Optics and Photonics Vol.4 No.5

A novel design for a Fresnel lens for a solar end-pumped laser is demonstrated in this paper. The new hybrid Fresnel lens includes two parts, inner and outer. The inner part is a twice-total-internal-reflection and vertical-transmission lens. The outer part is a once-total-reflection and vertical-transmission lens. The radius of the Fresnel lens is 600 mm, and its focal length is 750 mm. The concentrating performance of the Fresnel lens is examined using TracePro. The results show that the concentration efficiency has been greatly improved. The total concentration efficiency of the hybrid Fresnel lens reaches 73.2% when the radius of the laser rod is 3 mm. This design can simplify the concentration system of a solar endpumped solid-state laser.

Comparative analysis of Aurantii Fructus Immaturus and Aurantii Fructus via graphene‑assisted electrochemical chemometrics

Shuai Yan,Huiju Yang,Lianlin Su,Mingyue Zhou,Xiaopeng Wang 한국탄소학회 2023 Carbon Letters Vol.33 No.6

Aurantii Fructus Immature (AFI) and Aurantii Fructus (AF) are two important traditional Chinese herbs. As the harvesting time varies, the medicinal value of the plants is not uniform. Consequently, it has been difficult to quickly recognize them within the realm of traditional Chinese medicine. Separation and detection technologies are employed in combination to create fingerprints for identification. We proposed the utilization of graphene-assisted electrochemical fingerprint technology to acquire fingerprints of two varieties of medicinal materials. Simultaneously, we also obtained their fingerprints through HPLC. Two fingerprint recognition technologies were compared for their effectiveness. The findings demonstrate that the signals obtained through electrochemical fingerprinting have a higher recognition rate.

Pulse-width Adjustment Strategy for Improving the Dynamic Inductor Current Response Performance of a Novel Bidirectional DC-DC Boost Converter

Li, Mingyue,Yan, Peimin The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1

This paper presents a pulse-width adjustment (PWA) strategy for a novel bidirectional DC-DC boost converter to improve the performance of the dynamic inductor current response. This novel converter consists of three main components: a full-bridge converter (FBC), a high-frequency isolated transformer with large leakage inductance, and a three-level voltage-doubler rectifier (VDR). A number of scholars have analyzed the principles, such as the soft-switching performance and high-efficiency characteristic, of this converter based on pulse-width modulation plus phase-shift (PPS) control. It turns out that this converter is suitable for energy storage applications and exhibits good performance. However, the dynamic inductor current response processes of control variable adjustment is not analyzed in this converter. In fact, dc component may occur in the inductor current during its dynamic response process, which can influence the stability and reliability of the converter system. The dynamic responses under different operating modes of a conventional feedforward control are discussed in this paper. And a PWA strategy is proposed to enhance the dynamic inductor current response performance of the converter. This paper gives a detailed design and implementation of the PWA strategy. The proposed strategy is verified through a series of simulation and experimental results.

Constructing foldable cylindrical surfaces via unfolded waterbomb origami units

Zhao Yan,Wei Yinglei,Jia Yiyang,Li Shiling,Zhang Mingyue,Zeng Lanling,Yang Yang,Mitani Jun 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.4

Origami tessellations have shown the potential to be utilized for approximating curved target surfaces by folding a set of elemental units. As those units are in partially folded states, the origami approximation captures the outline of the target while demonstrating a corrugated surface. In this paper, we focus on the cylindrical surface and propose a method for constructing its discrete version via square or rectangular units with crease patterns inspired by the waterbomb tessellation. We unify the unit size through optimization to realize cost-efficient constructions. Three-dimensional curved structures are deployed by folding collinear creases between adjacent rows of units and the other creases in each row are remained unfolded. The deployed structure can still be folded to a compact state by folding all creases. To flexibly approximate the outline of the target surface, we analyse relationships between the width and height of the rectangular unit and utilize variations of the waterbomb tessellation to control the region of the origami structure when fully folded. The proposed method provides a novel solution to the so-called inverse-origami-design problem for generating foldable cylindrical surfaces using unfolded waterbomb origami units.

Identification of genomic diversity and selection signatures in Luxi cattle using whole-genome sequencing data

Hu Mingyue,Shi Lulu,Yi Wenfeng,Li Feng,Yan Shouqing 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.3

Objective: The objective of this study was to investigate the genetic diversity, population structure and whole-genome selection signatures of Luxi cattle to reveal its genomic characteristics in terms of meat and carcass traits, skeletal muscle development, body size, and other traits. Methods: To further analyze the genomic characteristics of Luxi cattle, this study sequenced the whole-genome of 16 individuals from the core conservation farm in Shandong region, and collected 174 published genomes of cattle for conjoint analysis. Furthermore, three different statistics (pi, Fst, and XP-EHH) were used to detect potential positive selection signatures related to selection in Luxi cattle. Moreover, gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment analyses were performed to reveal the potential biological function of candidate genes harbored in selected regions. Results: The results showed that Luxi cattle had high genomic diversity and low inbreeding levels. Using three complementary methods (pi, Fst, and XP-EHH) to detect the signatures of selection in the Luxi cattle genome, there were 2,941, 2,221 and 1,304 potentially selected genes identified, respectively. Furthermore, there were 45 genes annotated in common overlapping genomic regions covered 0.723 Mb, including PLAG1 zinc finger (PLAG1), dedicator of cytokinesis 3 (DOCK3), ephrin A2 (EFNA2), DAZ associated protein 1 (DAZAP1), Ral GTPase activating protein catalytic subunit alpha 1 (RALGAPA1), mediator complex subunit 13 (MED13), and decaprenyl diphosphate synthase subunit 2 (PDSS2), most of which were enriched in pathways related to muscle growth and differentiation and immunity. Conclusion: In this study, we provided a series of genes associated with important economic traits were found in positive selection regions, and a scientific basis for the scientific conservation and genetic improvement of Luxi cattle.

In-depth analysis of copycatting products based on economical and managerial viewpoints

FENG YAN,Mingyu ZHANG 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Nowadays, the copycatting products (or “Shan Zhai” products in Chinese) especially in mobile phone field are becoming popular in some countries like China due to the low cost and simple imitation in shape and functions. In fact, the copycatting products are facing more and more challenges from intellectual property protection and the risk of price war domestically due to the shortage of innovation. Still, we cannot deny that the copycatting products have certain rationality in some ways like attractive low price, comprehensive functions etc. They rush into the traditional IT industry within more fierce competition. In this paper, the author would analyze the status of the copycatting products in China, the relationship between copycatting and enterprise, the trend of copycatting by using mathematic model respectively.

Prevalence of Allergic Rhinitis Among Adults in Urban and Rural Areas of China: A Population-Based Cross-Sectional Survey

Ming Zheng,Xiangdong Wang,Mingyu Bo,Kuiji Wang,Yan Zhao,Fei He,Feifei Cao,Luo Zhang,Claus Bachert 대한천식알레르기학회 2015 Allergy, Asthma & Immunology Research Vol.7 No.2

Purpose: The aim of the present study was to compare the prevalence of self-reported and confirmable allergic rhinitis (AR) with positive skin pricktest (SPT) results among adults living in urban and rural areas of China. Methods: Adults from a community in Beijing and a village in Baoding wereselected as representative urban and rural dwellers, respectively. All eligible residents were enrolled from the population register and received aface-to-face interview using modified validated questionnaires. Equal sets of randomly selected self-reporting AR-positive and AR-negative participantswho responded to the questionnaires were also investigated using skin prick tests. Results: A total of 803 participants in the rural area and atotal of 1,499 participants in the urban area completed the questionnaires, with response rates being 75.9% and 81.5% respectively. The prevalenceof self-reported AR of the rural area (19.1%) was significantly higher than that of the urban area (13.5%). The elementary school of educational levelincreased the risk of having AR (adjusted OR=2.198, 95% CI=1.072-2.236) .The positive SPT rates among subjects with self-reported AR in therural and urban areas were 32.5% and 53.3%, respectively; the confirmable AR prevalence of 6.2% and 7.2% among the rural and urban adults, respectively. Conclusions: The prevalence of confirmable AR is similar between rural and urban areas in China, although there is a higher prevalenceof self-reported AR in the former. Purpose: The aim of the present study was to compare the prevalence of self-reported and confirmable allergic rhinitis (AR) with positive skin prick test (SPT) results among adults living in urban and rural areas of China. Methods: Adults from a community in Beijing and a village in Baoding were selected as representative urban and rural dwellers, respectively. All eligible residents were enrolled from the population register and received a face-to-face interview using modified validated questionnaires. Equal sets of randomly selected self-reporting AR-positive and AR-negative participants who responded to the questionnaires were also investigated using skin prick tests. Results: A total of 803 participants in the rural area and a total of 1,499 participants in the urban area completed the questionnaires, with response rates being 75.9% and 81.5% respectively. The prevalence of self-reported AR of the rural area (19.1%) was significantly higher than that of the urban area (13.5%). The elementary school of educational level increased the risk of having AR (adjusted OR=2.198, 95% CI=1.072-2.236) .The positive SPT rates among subjects with self-reported AR in the rural and urban areas were 32.5% and 53.3%, respectively; the confirmable AR prevalence of 6.2% and 7.2% among the rural and urban adults, respectively. Conclusions: The prevalence of confirmable AR is similar between rural and urban areas in China, although there is a higher prevalence of self-reported AR in the former.

RESEARCH ON LOCAL DISTURBANCE COOPERATIVE CONTROL OF HETEROGENEOUS VEHICLE PLATOON BASED ON SITUATION ASSESSMENT

Tingfang Zhang,Qidong Wang,Linfeng Zhao,Wuwei Chen,Bixin Cai,Mingyue Yan 한국자동차공학회 2024 International journal of automotive technology Vol.25 No.2

In the longitudinal driving of a heterogeneous platoon, external disturbances of local vehicles can cause safety problemsof the intended functionality. Therefore, a cooperative control method based on situation assessment is proposed. First, theminimum safe distance is determined according to the state of adjacent vehicles. A novel situation assessment model isestablished to characterize the stability of the platoon. Vehicle spacing, speed, and acceleration are selected as evaluationindicators. Then, an improved active disturbance rejection controller (IADRC) is designed to improve platoon stabilitythrough feedback compensation control. In addition, considering the unnecessary continuous involvement of the IADRC,its intervention time is determined by the situation assessment results. Finally, simulation and hardware-in-the-loop (HIL)experiments are carried out under two communication topologies. The results show that the proposed method can eff ectivelyimprove the stability and safety of the platoon.