A Novel Research of ZVZCS Synchronous Rectification Converter Based on Phase-shifted Full-bridge Control

Zhou Yongqin,Huang Ce,Chen Junjie,Shi Guijun,Zhou Meilan 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.6

Due to synchronous rectification based on Phase-shift full bridge converter is difficult to work in a state of soft switch, to solve this problem, this paper sets out an control approach of synchronous rectification based on the ZVZCS phase-shifted full-bridge, and the drive signal of synchronous rectification side uses leading-leg drive waveform after a certain time delay and applies the resonant principle in the switching process,not only keeping full bridge ZVZCS soft switching but also realizing MOSFET of the synchronous rectification ZVS. The simulation of saber and experimental research show that the converter has a good performance.

Visual Tracking Using Improved Multiple Instance Learning with Co-training Framework for Moving Robot

( Zhiyu Zhou ),( Junjie Wang ),( Yaming Wang ),( Zefei Zhu ),( Jiayou Du ),( Xiangqi Liu ),( Jiaxin Quan ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.11

Object detection and tracking is the basic capability of mobile robots to achieve natural human-robot interaction. In this paper, an object tracking system of mobile robot is designed and validated using improved multiple instance learning algorithm. The improved multiple instance learning algorithm which prevents model drift significantly. Secondly, in order to improve the capability of classifiers, an active sample selection strategy is proposed by optimizing a bag Fisher information function instead of the bag likelihood function, which dynamically chooses most discriminative samples for classifier training. Furthermore, we integrate the co-training criterion into algorithm to update the appearance model accurately and avoid error accumulation. Finally, we evaluate our system on challenging sequences and an indoor environment in a laboratory. And the experiment results demonstrate that the proposed methods can stably and robustly track moving object.

Comparison of leaf transcriptomes of cassava “Xinxuan 048” diploid and autotetraploid plants

Ling Yin,Junjie Qu,Huiwen Zhou,Xiaohong Shang,Hui Fang,Jiang Lu,Huabing Yan 한국유전학회 2018 Genes & Genomics Vol.40 No.9

Polyploidy breeding of cassava has been used to improve cassava traits over the past years. We previously reported in vitro induction of tetraploids in the cassava variety “Xinxuan 048” using colchicine. Significant differences in morphology and anatomy were found between the diploid and tetraploid plants. However, very little is known about the transcriptome difference between them. In this study, morphological and physiological characteristics including leaf thickness, plant height, internode length, chlorophyll content, and photosynthetic capacity were measured. Further, we investigated and validated the difference in gene expression patterns between cassava “Xinxuan 048” tetraploid genotype and its diploid plants using RNA sequencing (RNAseq) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Significant differences in morphology and physiology were observed during tetraploidization. A comparison revealed that tetraploidy induced very limited changes in the leaf transcriptomes of cassava “Xinxuan 048” diploid and autotetraploid plants. However, the differentially expressed genes (DEGs) between 2× and 4× plants, especially those upregulated in 4× plants, were strongly associated with hormonal and stress responses. Large changes in morphology and physiology between the diploid cassava “Xinxuan 048” and its autotetraploid were not associated with large changes in their leaf transcriptomes. Moreover, the differently expressed genes related to the regulation of gibberellin and brassinosteroids potentially explained why the plant height and internode length of 4× plants became shorter. Collectively, our results suggest that 4× cassava is potentially valuable for breeding strains with improved stress resistance.

Trimethyl-Ammonium Alkaline Anion Exchange Membranes with the Vinylbenzyl Chloride/Acrylonitrile Main Chain

Zhenghan Li,Junjie Chen,JinYue Zhou,YiWen Nie,Chunhui Shen,Shanjun Gao 한국고분자학회 2021 Macromolecular Research Vol.29 No.7

The main chain of polyolefin was synthesized by copolymerization of 4 - vinylbenzyl chloride (VBC) and acrylonitrile (AN), and trimethylamine is used for quaternization to prepare heterogeneous benzyl trimethyl-ammonium anion exchange membranes (Heter-X) and homogeneous benzyl trimethyl-ammonium anion exchange membrane (Homo-X). The results of Fourier-transform infrared (FT-IR), gel permeation chromatography (GPC), and 1H nuclear magnetic resonance (NMR) showed that VBC and AN were successfully copolymerized to form a polymer with a certain molecular weight, and trimethylamine was successfully quaternized. The prepared membranes exhibited good thermal stability and mechanical properties. The theoretical ion exchange capacity (IEC) values of Homo-3 and Heter-3 are the same, but the conductivity at 80 °C were 0.0572 S cm-1 and 0.0505 S cm-1. The results showed that the homogeneous method has a higher degree of quaternization and a more uniform distribution of quaternary ammonium groups, forming a more obvious microphase separation structure, which can also be seen in the atomic force microscopy (AFM) diagram. After being soaked in 1M KOH solution for 480 h, the ionic conductivity of Homo-6 and Heter-6 can still remain 91.4% and 85.5%, and the IEC loss rates were 17.21% and 24.34%. These results indicate that the prepared membranes are promising materials for application in fuel cells.

Isoperistaltic side-to-side anastomosis for the surgical treatment of Crohn disease

Wenhao Chen,Junjie Zhou,Min Chen,Congqing Jiang,Qun Qian,Zhao Ding 대한외과학회 2022 Annals of Surgical Treatment and Research(ASRT) Vol.103 No.1

Purpose: Increasing evidence has shown an association of surgical technique, particularly anastomotic configuration, with postoperative recurrence of CD. This pilot study aimed to evaluate short-term outcomes of isoperistaltic side-to-side anastomosis (ISSA) employed on Crohn disease (CD) patients. Methods: Data were retrieved from a prospectively maintained database. Postoperatively, all patients were followed up with close endoscopic (ileocolonoscopy) surveillance. Results: From January 2017 to May 2021, 30 patients diagnosed with CD who underwent ISSA were compared with 45 CD patients who underwent antiperistaltic side-to-side anastomosis (ASSA). The 2 groups were comparable in baseline demographics and clinical characteristics. No significant differences were observed between groups regarding postoperative safety issues, including anastomotic leak, abdominal/pelvic abscess, length of hospital stay, readmission rate within 30 days, etc. At postoperative 24th month, reduced endoscopic recurrence was observed in the ISSA group compared with that in the ASSA group (18 of 24, 75.0%, . 36 of 38, 94.7%; P = 0.024). Regarding surgical recurrence, there was 0% in the ISSA group . 4.4% (2 of 45) in the ASSA group (P = 0.510). Conclusion: In this study, we aimed to explore the influence of ISSA on postoperative recurrence in CD patients, and the preliminary results show that ISSA was technically safe and feasible, and appears to be effective in reducing postoperative recurrence in CD patients. However, our conclusion was underpowered due to small sample size and inadequate follow- up. We proposed ISSA be considered as another alternative option in the toolbox of inflammatory bowel disease surgeons when performing anastomosis on CD patients.

Characteristics Detected on Computed Tomography Angiography Predict Coronary Artery Plaque Progression in Non-Culprit Lesions

Yahang Tan,Jia Zhou,Ying Zhou,Xiaobo Yang,Junjie Yang,Yundai Chen 대한영상의학회 2017 Korean Journal of Radiology Vol.18 No.3

Objective: This study sought to determine whether variables detected on coronary computed tomography angiography (CCTA) would predict plaque progression in non-culprit lesions (NCL). Materials and Methods: In this single-center trial, we analyzed 103 consecutive patients who were undergoing CCTA and percutaneous coronary intervention (PCI) for culprit lesions. Follow-up CCTA was scheduled 12 months after the PCI, and all patients were followed for 3 years after their second CCTA examination. High-risk plaque features and epicardial adipose tissue (EAT) volume were assessed by CCTA. Each NCL stenosis grade was compared visually between two CCTA scans to detect plaque progression, and patients were stratified into two groups based on this. Logistic regression analysis was used to evaluate the factors that were independently associated with plaque progression in NCLs. Time-to-event curves were compared using the log-rank statistic. Results: Overall, 34 of 103 patients exhibited NCL plaque progression (33%). Logistic regression analyses showed that the NCL progression was associated with a history of ST-elevated myocardial infarction (odds ratio [OR] = 5.855, 95% confidence interval [CI] = 1.391–24.635, p = 0.016), follow-up low-density lipoprotein cholesterol level (OR = 6.832, 95% CI = 2.103–22.200, p = 0.001), baseline low-attenuation plaque (OR = 7.311, 95% CI = 1.242–43.028, p = 0.028) and EAT (OR = 1.015, 95% CI = 1.000–1.029, p = 0.044). Following the second CCTA examination, major adverse cardiac events (MACEs) were observed in 12 patients, and NCL plaque progression was significantly associated with future MACEs (log rank p = 0.006). Conclusion: Noninvasive assessment of NCLs by CCTA has potential prognostic value.

Investigation on the Temperature Characteristics of Water Inner-Cooled Stator Coil of HTS Motor

Dong Qi,Zhao Junjie,Zhou Yong,Fu Xiaoli 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.6

This study investigates the temperature characteristics of water inner-cooled stator coil based on Litz wire for high temperature superconducting (HTS) motor. Rich experience in transposed Litz bundle windings is accumulated by manufacturing scaled-down water inner-cooled coil prototypes for high-capacity HTS motors. On this basis, the temperature rise test and calculation simulation are carried out. The maximum relative error between the two results is only 5.13%, which verified the rationality of the numerical temperature field calculation method. Subsequently, the effects of pipe blockage and epoxy thermal conductivity changes on the coil temperature are further explored. Thus, a relatively complete method for evaluating the temperature characteristics of water inner-cooled windings is formed, which can greatly help guide the design and manufacture of future high-capacity HTS motors.

Novel Dead-time Segmented Compensation Strategy for a Wide Impedance Angle Range in a Three-phase Inverter with a Resistance-Inductance Load

Zhang Siyan,Wang Xudong,Ma Junjie,Duan Ruizhen,Zhou Kai 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

The dead-time setting in space vector pulse width modulation (SVPWM) causes inverter output waveform distortion and performance degradation. This paper proposes a novel dead-time segmented compensation strategy for a wide impedance angle range in a three-phase inverter with a resistance-inductance load. Since the load impedance angle ( φ ) of the threephase inverter produces diff erent dead-time eff ects, in this paper, it is divided into two intervals of [0 30°] and [30° 90°] and a corresponding dead-time segmented compensation strategy is proposed, which solves the limitation of the traditional time compensation scheme that analyzes only the resistive load. In addition, this paper uses the conversion relationship between the power factor ( λ ) and φ to determine the current polarity of each sector in the vector space, which avoids the detection error of the current zero-crossing point in the traditional compensation scheme. The simulation and experimental results demonstrate that this method eff ectively reduces the total harmonic distortion (THD) of the inverter output current signal by approximately 30% and is easy to program, which improves the inverter output performance.

Modulatory Potential of LncRNA Zfas1 for Inflammation and Neuronal Apoptosis in Temporal Lobe Epilepsy

Chuan He,Caixia Su,Wentong Zhang,Qin Zhou,Xu Shen,Junjie Yang,Naixian Shi 연세대학교의과대학 2021 Yonsei medical journal Vol.62 No.3

Purpose: This study aimed to elucidate whether lncRNA ZFAS1 is involved in neuronal apoptosis and inflammation in temporal lobe epilepsy (TLE). Materials and Methods: Ninety-six TLE patients were recruited, and their peripheral venous blood was gathered to determine Zfas1 expression with polymerase chain reaction. Neurons were separated from hippocampal tissue of newborn SD rats, and siZfas1 or pcDNA3.1-Zfas1 was transfected into the neurons. Inflammatory cytokines released by neurons were determined, and neuronal activities were evaluated through MTT assay, colony formation assay, and flow cytometry. Results: Serum levels of Zfas1 were higher in TLE patients than in healthy controls (p<0.05). Furthermore, Zfas1 expression in neurons was raised by pcDNA3.1-Zfas1 and declined after silencing of Zfas1 (p<0.05). Transfection of pcDNA-Zfas1 weakened the viability and proliferation of neurons and increased neuronal apoptosis (p<0.05). Meanwhile, pcDNA3.1-Zfas1 transfection promoted lipopolysaccharide-induced release of cytokines, including tumor necrosis factor-α, interleukin (IL)-1, IL-6, and intercellular adhesion molecule-1 (p<0.05), and boosted NF-κB activation by elevating the expression of NF-κB p65, pIκBα, and IKKβ in neurons (p<0.05). Conclusion: Our results indicated that lncRNA ZFAS1 exacerbates epilepsy development by promoting neuronal apoptosis and inflammation, implying ZFAS1 as a promising treatment target for epilepsy.

Preliminary conceptual design of a small high-flux multi-purpose LBE cooled fast reactor

Xiong Yangbin,Duan Chengjie,Zeng Qin,Ding Peng,Song Juqing,Zhou Junjie,Xu Jinggang,Yang Jingchen,Li Zhifeng 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.8

The design concept of a Small High-flux Multipurpose LBE(Lead Bismuth Eutectic) cooled Fast Reactor (SHMLFR) was proposed in the paper. The primary cooling system of the reactor is forced circulation, and the fuel element form is arc-plate loaded high enrichment MOX fuel. The core is cylindrical with a flux trap set in the center of the core, which can be used as an irradiation channel. According to the requirements of the core physical design, a series of physical design criteria and constraints were given, and the steady and transient parameters of the reactor were calculated and analyzed. Regarding the thermal and hydraulic phenomena of the reactor, a simplified model was used to conduct a preliminary analysis of the fuel plates at special positions, and the temperature field distribution of the fuel plate with the highest power density under different coolant flow rates was simulated. The results show that the various parameters of SHMLFR meet the requirements and design criteria of the physical design of the core and the thermal design of the reactor. This implies that the conceptual design of SHMLFR is feasible