Frequency Characteristics of the d-q Synchronous-Frame Current Reference Generation Methods for Active Power Filter

Xiaoyu Wang,Jinjun Liu,Jinku Hu,Yuji Meng,Chang Yuan 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

The d-q harmonics detection algorithms are dominant methods to generate current reference for active power filter (APF). They are often processed in synchronous frame and time domain. This paper researches the frequency characteristics of d-q synchronous transformation which are quite related to the design of close loop regulator and analysis of the performance. Intuitively, the synchronous transformation is explained with amplitude modulation (AM) in this paper. Then the synchronous filter is proven as time-invariant linear transformation and modeled with transfer functions in stationary frame and frequency domain. The frequency-domain analytical models imply that the synchronous transformation has an equivalent effect of frequency transformation, with which the synchronous filter achieves a band pass filter from the low pass filter in synchronous frame. To simplify the analytical model, an instantaneous positive/negative sequence frame is proposed as an expansion of symmetrical components theory. Based on these frequency analytical models, the synchronous filter is compared with the traditional filters in stationary frame. Further more, the d-q harmonics detection methods are improved to get rid of the inherent coupling of synchronous transformation. Typical examples are given to verify previous analysis and comparison. Simulation and experimental results are also given.

유교 孝 문화 관점에서 본 고령화 사회 부모 봉양에 관한 연구

WANG XIAOYU 한국효학회 2022 효학연구 Vol.- No.35

Background: The aging population has become a prominent social problem in the world. The United Nations has sought to solve the aging problem since the 1980s in response to the growing aging of the world's population. With various changes and developments such as socioeconomic structure and demographic structure, the succession and development of traditional filial piety culture faces many practical problems such as population aging, economic pressure, and population flow.As times change and family structure change, traditional filial piety culture is anachronistic in modern society, but in filial piety culture, it cannot be stopped from a great tradition that respects the humanistic emotions and humanism of the elderly. Purpose: The text re-examines and reinterprets the philosophical basis behind Confucian thought by combining the plight of supporting the elderly in modern society with an aging society as a specific research background. By fusing the traditional filial piety idea of Confucianism with the guarantee of human rights in modern society, it provided solutions to various problems arising in the process of caring for parents in modern society. Methodology/Approach: Approach from the content of filial piety and the difficulty of caring for parents in an aging society, and briefly analyze the expression and cause of filial piety deficiency in modern society. From this, we revealed the lack of caring for the elderly and the difficulties facing the culture of filial piety in an aging society, and thought about how filial piety can adapt to an aging society with the development of society and the times. Furthermore, the values and meanings of Confucian filial piety culture in caring for parents were also discussed. Findings/Conclusions: The filial piety culture has been a social consciousness that has existed in Confucian culture for thousands of years and has had a serious impact on people's values, ways of thinking, behavior, and customs. The filial piety culture makes children and parents maintain an intimate relationship, and despite various problems caused by the aging population in modern society, the filial piety of oil prices still has important theoretical and practical values. No matter how human civilization develops in the future, supporting and respecting the elderly should be an important sign of a civilized society and a social virtue of modern people. In modern society, Confucian filial piety must return to an important position in family ethics thought, and on that basis, filial piety still exerts important value in modern society. Implications: The culture of filial piety helps improve family relations, harmonize family relations, and stabilize society. The filial piety culture can increase the moral virtues and social responsibility of the people, encourage justice by developing a good social climate, and, above all, alleviate social problems caused by the aging population. 배경: 인구의 고령화는 현재 세계에서 두드러진 사회 문제가 되었다. 유엔은 갈수록 빨라지는 전 세계 인구의 고령화에 맞서 1980년대부터 고령화 문제의 해결을 모색하였다. 사회경제 구조, 인구 구조 등 다방면의 변화와 발전에 따라 전통적인 孝문화의 계승과 발전은 인구 고령화, 경제적 압박, 인구 유동 등 많은 현실적 문제에 직면해 있다. 시대가 변하고 가족구조가 바뀌어 전통 孝문화는 현대사회에서 시대착오적인 면이 많지만 노인의 인문학적 정서와 휴머니즘을 존중하는 훌륭한 전통은 끊을 수 없다. 목적: 본문은 고령화 사회를 특정한 연구배경으로 하여, 현대 사회 노인을 봉양의 곤경 문제를 결합함으로써 유가 사상 이면의 철학적 근거를 재조명하고 재해석한다. 유가의 전통적인 효도 사상을 융합함으로써 현대사회에서 부모를 봉양하는 과정 가운데서 발생하는 여러 문제점에 대한 해결 방법을 제공하였다. 방법론/접근: 효도의 내용, 고령화 사회에서 부모를 봉양하는 곤경 등으로부터 접근하여 현대사회 효도 결핍의 표현과 원인을 간략히 분석한다. 이로부터 노인 봉양의 부족한 점과 孝문화가 고령화 사회에서 직면한 어려움을 드러내었고, 사회와 시대의 발전에 따라 효도가 어떻게 고령화 사회에 적응할 수 있는가에 대해 사고해보았다. 나아가 자녀들이 부모를 봉양하는 데에 있어서 유가의 孝문화가 갖는 가치와 의미에 대해서도 토론하였다. 결과/결론: 孝는 유교 문화권에 수천 년 동안 존재해 온 사회의식으로 사람들의 가치관념, 사고방식, 행동방식, 풍습에 심각한 영향을 미쳤다. 孝는 자녀와 부모의 친밀한 관계를 유지하게 만들며, 현대사회에서 인구 고령화로 인한 여러 문제에도 유가의 효도는 여전히 중요한 이론과 실천적 가치를 지니고 있다. 미래 인류 문명이 어떻게 발전하든 노인을 부양하고 존중하는 것은 문명사회의 중요한 징표이자 현대인의 사회적 미덕이 되어야 한다. 현대사회에서 유가의 孝는 가족윤리 사상의 중요한 지위로 돌아가야 하며, 그 바탕 위에서 孝는 현대사회에서 여전히 중요한 가치를 발휘한다. 시사점: 孝문화는 가족 관계의 개선과 가족관계의 조화 및 사회 안정에 도움을 준다. 孝문화는 국민의 도덕적 덕목과 사회적 책임감을 높여주고 좋은 사회풍토를 키워 정의감을 북돋으며, 무엇보다 인구 고령화에 따른 사회문제를 완화시킬 수 있다.

Blood lipids and all-cause mortality among old people: the Chinese Longitudinal Healthy Longevity Survey 2008-2018

Wang Rongxi,Yu Xiaoyue,Wang Zhiqiang,Liu Yujie,Chen Hui,Liu Shangbin,XU CHENG,Chen Yingjie,Xia Danni,Ge Xin,Chang Ruijie,Xu Gang,Xiang Mi,Wang Ying,Shen Tian,Hu Fan,Cai Yong 한국역학회 2022 Epidemiology and Health Vol.44 No.-

OBJECTIVES: Proper blood lipid levels are essential for survival in older adults, but inconsistent relationships have been reported between blood lipids and all-cause mortality in the elderly. METHODS: This retrospective longitudinal study analyzed data from 1,067 Chinese older adults enrolled in the Chinese Longitudinal Healthy Longevity Survey collected in 2008 and followed up until death or December 31, 2018. The outcome was allcause mortality. Multivariate Cox regression analyses were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) with stratification by age (60-80, 80-100, or ≥ 100 years) for further analysis. The survival probability according to lipid profile quartiles was calculated using Kaplan-Meier curves and the log-rank test. RESULTS: The participants’ mean age was 84.84 years, and 57.0% were female. In total, 578 individuals died, and 277 were lost to follow-up. The mean total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels were higher among those who died than among those who survived. Participants in the second HDL-C quartile and the highest LDL-C and triglyceride (TG) quartiles had 28% higher, 23% lower, and 49% lower risks of all-cause mortality, respectively. After further adjustment, the associations remained except for HDL-C, and additional associations were observed between all-cause mortality and the third TC and LDL-C quartiles and the second TG quartile (HR, 1.44; 95% CI, 1.01 to 2.06; HR, 0.68; 95% CI, 0.49 to 0.94; HR, 0.79; 95% CI, 0.62 to 0.99, respectively). CONCLUSIONS: Older adults should maintain an LDL-C level of 1.91-2.47 mmol/L and a TG level of no less than 1.66 mmol/L.

Structural understanding of the transport cycle of glutamate transporters

Xiaoyu Wang,SeCheol Oh 한국구조생물학회 2020 Biodesign Vol.8 No.4

Since the determination of the first crystal structure of a glutamate transporter homolog GltPh 16 years ago, the structural biology of glutamate transporter has progressed remarkably. To understand the complicated transport cycle of ion-coupled glutamate transport, each state’s high-resolution structural information in the transport cycle is essential. Many of the structural information and insights about the sodium-coupled symport mechanism were gained from structural studies of prokaryotic homologs sodium-aspartate symporters, GltPh and GltTk. Moreover, further insights were gained from recently unveiled structures of mammalian glutamate transporters (EAATs). Here we review GltPh, GltTk, and mammalian glutamate transporters’ structures and discuss how they help us to understand the ion-coupled transport mechanism in glutamate transporters.

Frequency-Domain Transformation Approaches to Develop the d-q Synchronous-Frame Models of Three-Phase Symmetrical Networks and Applications in Modeling of PWM Power Converters

Xiaoyu Wang,Jinjun Liu,Yuji Meng,Jinku Hu,Chang Yuan 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

Although state-space averaging small-signal modeling techniques are successfully established in DC-DC converters and three-phase sinusoidal PWM converters, these approaches are limited only to low-order systems, and the modeling process is very complex. This paper proposes two equivalent approaches in frequency domain to develop the d-q synchronous-frame models from stationary-frame models for arbitrary three-phase symmetrical circuits. The first modeling approach is illustrated with frequency transformation, by which the target synchronous-frame models could be easily obtained by frequency transformation of the prototype stationary-frame models. The second modeling approach is based on the reactive elements substitutions. These two approaches can be proven to be equivalent, and the first approach is suitable for input-output models, while the second approach is preferable for state-space models. As illustrative examples, these approaches are applied to develop the synchronous-frame models of large three-phase systems with PWM converters. They are proven valid with the comparison with current published models.

Frequency Characteristics of the Synchronous-Frame Based D-Q Methods for Active Power Filters

WANG Xiaoyu,LIU Jinjun,HU Jinku,MENG Yuji,YUAN Chang 전력전자학회 2008 JOURNAL OF POWER ELECTRONICS Vol.8 No.1

The d-q harmonic detecting algorithms are dominant methods to generate current references for active power filters (APF). They are often implemented in the synchronous frame and time domain. This paper researches the frequency characteristics of d-q synchronous transformations, which are closely related to the analysis and design issues of control system. Intuitively, the synchronous transformation is explained with amplitude modulation (AM) in this paper. Then, the synchronous filter is proven to be a time-invariant and linear system, and its transfer function matrix is derived in the stationary frames. These frequency-domain models imply that the synchronous transformation has an equivalent effect of frequency transformation. It is because of this feature, the d-q method achieves band-pass characteristics with the low pass filters in the synchronous frame at run time. To simplify these analytical models, an instantaneous positive-negative sequence frame is proposed as expansion of traditional symmetrical components theory. Furthermore, the synchronous filter is compared with the traditional bind-pass filters based on these frequency-domain analytical models. The d-q harmonic detection methods are also improved to eliminate the inherent coupling effect of synchronous transformation. Typical examples are given to verify previous analysis and comparison. Simulation and experimental results are also provided for verification.

HOW MUCH DOES PRODUCT-HARM CRISIS MATTER TO OVERALL SATISFACTION WITH THE SUPPLIERS?

Xiaoyu Wang,Simon Shufeng Xiao 동중앙아시아경상학회 2013 한몽경상학회 학술대회 Vol.2013 No.2

ssc-miR-185 targets cell division cycle 42 and promotes the proliferation of intestinal porcine epithelial cell

Wang, Wei,Wang, Pengfei,Xie, Kaihui,Luo, Ruirui,Gao, Xiaoli,Yan, Zunqiang,Huang, Xiaoyu,Yang, Qiaoli,Gun, Shuangbao Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.5

Objective: microRNAs (miRNAs) can play a role in a variety of physiological and pathological processes, and their role is achieved by regulating the expression of target genes. Our previous high-throughput sequencing found that ssc-miR-185 plays an important regulatory role in piglet diarrhea, but its specific target genes and functions in intestinal porcine epithelial cell (IPEC-J2) are still unclear. We intended to verify the target relationship between porcine miR-185 and cell division cycle 42 (CDC42) gene in IPEC-J2 and to explore the effect of miR-185 on the proliferation of IPEC-J2 cells. Methods: The TargetScan, miRDB, and miRanda software were used to predict the target genes of porcine miR-185, and CDC42 was selected as a candidate target gene. The CDC42-3' UTR-wild type (WT) and CDC42-3'UTR-mutant type (MUT) segments were successfully cloned into pmirGLO luciferase vector, and the luciferase activity was detected after co-transfection with miR-185 mimics and pmirGLO-CDC42-3'UTR. The expression level of CDC42 was analyzed using quantitative polymerase chain reaction and Western blot. The proliferation of IPEC-J2 was detected using cell counting kit-8 (CCK-8), methylthiazolyldiphenyl-tetrazolium bromide (MTT), and 5-ethynyl-2'-deoxyuridine (EdU) assays. Results: Double enzyme digestion and sequencing confirmed that CDC42-3'UTR-WT and CDC42-3'UTR-MUT were successfully cloned into pmirGLO luciferase reporter vector, and the luciferase activity was significantly reduced after co-transfection with miR-185 mimics and CDC42-3'UTR-WT. Further we found that the mRNA and protein expression level of CDC42 were down-regulated after transfection with miR-185 mimics, while the opposite trend was observed after transfection with miR-185 inhibitor (p<0.01). In addition, the CCK-8, MTT, and EdU results demonstrated that miR-185 promotes IPEC-J2 cells proliferation by targeting CDC42. Conclusion: These findings indicate that porcine miR-185 can directly target CDC42 and promote the proliferation of IPEC-J2 cells. However, the detailed regulatory mechanism of miR-185/CDC42 axis in piglets' resistance to diarrhea is yet to be elucidated in further investigation.

Comparison of Conventional PCR, Multiplex PCR, and Loop-Mediated Isothermal Amplification Assays for Rapid Detection of <i>Arcobacter</i> Species

Wang, Xiaoyu,Seo, Dong Joo,Lee, Min Hwa,Choi, Changsun,Onderdonk, A. B. American Society for Microbiology 2014 Journal of clinical microbiology Vol.52 No.2

<P>This study aimed to develop a loop-mediated isothermal amplification (LAMP) method for the rapid detection of <I>Arcobacter</I> species. Specific primers targeting the 23S ribosomal RNA gene were used to detect <I>Arcobacter butzleri</I>, <I>Arcobacter cryaerophilus</I>, and <I>Arcobacter skirrowii</I>. The specificity of the LAMP primer set was assessed using DNA samples from a panel of <I>Arcobacter</I> and <I>Campylobacter</I> species, and the sensitivity was determined using serial dilutions of <I>Arcobacter</I> species cultures. LAMP showed a 10- to 1,000-fold-higher sensitivity than multiplex PCR, with a detection limit of 2 to 20 CFU per reaction <I>in vitro</I>. Whereas multiplex PCR showed cross-reactivity with <I>Campylobacter</I> species, the LAMP method developed in this study was more sensitive and reliable than conventional PCR or multiplex PCR for the detection of <I>Arcobacter</I> species.</P>

Transfer Pricing and PE taxation in China

Wang Xiaoyue 한국국제조세협회 2008 조세학술논집 Vol.24 No.2