Coordinated Control Strategies with and without Circulating Current in Unified Power Quality

Feng, Xing-tian,Zhang, Zhi-hua The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

Under traditional unified power quality conditioner (UPQC) control, a UPQC series converter (SC) is mainly used to handle grid-side power quality problems while its parallel converter (PC) is mainly used to handle load-side power quality problems. The SC and PC are relatively independent. The SC is usually in standby mode and it only runs when the grid voltage abruptly changes. In this paper, novel UPQC coordinated control strategies are proposed which use the SC to share the reactive power compensation function of the PC especially without grid-side power quality problems. However, in some cases, there will be a circulating current between the SC and the PC, which will probably influence the compensation fashion, the compensation capacity, or the normal work of the UPQC. Through an active power circulation analysis, strategies with and without a circulating current are presented which fuses the reactive power allocation strategy of the SC and the PC, the composite control strategy of the SC and the compensation strategy of the DC storage unit. Both of the strategies effectively solve the SC long term idle problem, limit the influence of the circulating current, optimize all of the UPQC units and reduce the production cost. An analysis, along with simulation andexperimental results, is presented to verify the feasibility and effectiveness of the proposed control strategies.

Coordinated Control Strategies with and without Circulating Current in Unified Power Quality Conditioners

Xing-tian Feng,Zhi-hua Zhang 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.5

Under traditional unified power quality conditioner (UPQC) control, a UPQC series converter (SC) is mainly used to handle grid-side power quality problems while its parallel converter (PC) is mainly used to handle load-side power quality problems. The SC and PC are relatively independent. The SC is usually in standby mode and it only runs when the grid voltage abruptly changes. In this paper, novel UPQC coordinated control strategies are proposed which use the SC to share the reactive power compensation function of the PC especially without grid-side power quality problems. However, in some cases, there will be a circulating current between the SC and the PC, which will probably influence the compensation fashion, the compensation capacity, or the normal work of the UPQC. Through an active power circulation analysis, strategies with and without a circulating current are presented which fuses the reactive power allocation strategy of the SC and the PC, the composite control strategy of the SC and the compensation strategy of the DC storage unit. Both of the strategies effectively solve the SC long term idle problem, limit the influence of the circulating current, optimize all of the UPQC units and reduce the production cost. An analysis, along with simulation and experimental results, is presented to verify the feasibility and effectiveness of the proposed control strategies.

Risk Factors, Patterns and Long-Term Prognosis of Early and Late Recurrence in Patients with Hepatitis B Virus-Associated Hepatocellular Carcinoma

( Tian Yang ),( Ming-da Wang ),( Chao Li ),( Lei Liang ),( Hao Xing ),( Li-yang Sun ),( Bing Quan ),( Han Wu ),( Xin-fei Xu ),( Timothy M ),( Pawlik ),( Wan Yee Lau ),( Feng Shen ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: Survival after liver resection of hepatocellular carcinoma (HCC) remains poor due to a high incidence of recurrence. We sought to investigate risk factors, patterns, and long-term prognosis among patients with early and late recurrence after liver resection for hepatitis B virus (HBV)-associated HCC. Methods: Data of consecutive patients undergoing curative resection for HBV-associated HCC were analyzed. According to the time to recurrence after surgery, recurrence was divided into early (≤ 2 years) and late recurrence (> 2 years). Characteristics, patterns of initial recurrence and post-recurrence survival (PRS) were compared between patients with early and late recurrence. Risk factors of early and late recurrence, and predictors of PRS were identified by univariable and multivariable Cox-regression analyses. Results: mong 894 patients, 322 (36.0%) and 282 (31.5%) developed early and late recurrence, respectively. On multivariable analyses preoperative HBV-DNA>104 copies/ml was associated with both early and late recurrence, while postoperative no/ irregular antiviral therapy was associated with late recurrence. Compared with patients with late recurrence, patients with early recurrence had a lower proportion of intrahepatic only recurrence (72.0% vs. 91.1%, P<0.001), as well as a lower chance of receiving potentially-curative treatments for recurrence (33.9% vs. 50.7%, P<0.001) and a worse median PRS (19.1 vs. 37.5 months, P<0.001). Multivariable analysis demonstrated that early recurrence was independently associated with worse PRS (HR 1.361, 95%CI 1.094-1.692, P=0.006). Conclusions: Although risk factors associated with early recurrence and late recurrence were different, a high preoperative HBV-DNA load was an independent hepatitis-related risk for both early and late recurrence. Early recurrence was associated with

Association of TNF-α-308 and -238 Polymorphisms with Risk of Cervical Cancer: A Meta-analysis

Pan, Feng,Tian, Jing,Ji, Chu-Shu,He, Yi-Fu,Han, Xing-Hua,Wang, Yong,Du, Jian-Ping,Jiang, Feng-Shou,Zhang, Ying,Pan, Yue-Yin,Hu, Bing Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Published data on the associations between tumor necrosis factor-alpha (TNF-${\alpha}$) promoter -308G>A and -238G>A polymorphisms and cervical cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Data were collected from MEDLINE and PubMed databases. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated in a fixed/random effect model. 13 separate studies including 3294 cases and 3468 controls were involved in the meta-analysis. We found no association between TNF-${\alpha}$-308G>A polymorphism and cervical cancer in overall population. In subgroup analysis, significantly elevated risks were found in Caucasian population (A vs. G: OR = 1.43, 95% CI = 1.00-2.03; AA vs. GG: OR = 2.09, 95% CI = 1.34-3.25; Recessive model: OR = 2.09, 95% CI = 1.35-3.25) and African population (GA vs. GG: OR = 1.53, 95% CI = 1.02-2.30). An association of TNF-${\alpha}$-238G>A polymorphism with cervical cancer was found (A vs. G: OR = 0.61, 95% CI = 0.47-0.78; GA vs. GG: OR = 0.59, 95% CI = 0.45-0.77; Dominant model: OR = 0.59, 95% CI = 0.46-0.77). When stratified by ethnicity, similar association was observed in Caucasian population (A vs. G: OR = 0.62, 95% CI = 0.46-0.84; GA vs. GG: OR = 0.59, 95% CI = 0.43-0.82; Dominant model: OR = 0.60, 95% CI = 0.44-0.83). In summary, this meta-analysis suggests that TNF-${\alpha}$-238A allele significantly decreased the cervical cancer risk, and the TNF-${\alpha}$-308G>A polymorphism is associated with the susceptibility to cervical cancer in Caucasian and African population.

Resistance Reduction Scheme for Tower Grounding with Conductive Cement

Lun Li,Tian Xu,Pei Feng,Liu Xin,Jia Lulu,Deng Chenxing,Wang Xing,Lan Fen,Cheng Hongbo 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

The construction conditions of transmission lines are becoming more and more diffi cult. It is necessary to fi nd new ways to reduce the grounding resistance of poles and towers at high soil resistivity and small construction area. Conductive cement samples with graphite, stainless steel fi bers, and their mixtures as conductive phases materials were prepared, the resistivity, fl exural strength and compressive strength were tested, compared and analyzed. The graphite and stainless steel fi ber conductive cement with better comprehensive performance was selected out for tower grounding. The application schemes of conductive cement for tower grounding were designed and compared, the partial wrapping scheme was selected and its application methods under diff erent soil resistivity was analyzed. The analysis results can provide theoretical basis and guidance for the application of conductive cement in transmission tower grounding, the feasibility of scheme is proved by the fi eld application.

Multiple Particle Production in Proton-proton Collisions at Energies Available at the Large Hadron Collider

Jin-Ming Feng,Cai-Xing Tian,Rui-Fang Si,Fu-Hu Liu 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.4

A shift three-source model is used in this paper to describe the multiplicity and the pseudorapidity distributions of final-state charged particles produced in proton-proton collisions at energies available at the Large Hadron Collider (LHC). The three kinds of sources are central sources arising from gluon-gluon collisions, target fragmentation sources arising from gluon- or quark-induced collisions with target quarks, and projectile fragmentation sources arising from gluon- or quark-induced collisions with projectile quarks. The central, target fragmentation, and projectile fragmentation sources each have shifts around their centers. The results calculated by using the shift three-source model are in agreement with the experimental data of the ALICE (A Large Ion Collider Experiment) and the CMS (Compact Muon Solenoid experiment) Collaborations.

Triterpenoid saponins from Clinopodium chinense (Benth.) O. Kuntze and their biological activity

Yin-Di Zhu,Jing-Yi Hong,Feng-Da Bao,Na Xing,Ling-Tian Wang,Zhong-Hao Sun,Yun Luo,Hai Jiang,Xudong Xu,Nai-Liang Zhu,Hai-Feng Wu,Gui-Bo Sun,Jun-Shan Yang 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.12

Four new ursane-type triterpenoid saponins, clinopoursaponins A–D (1–4), six new oleanane-type triterpenoid saponins, clinopodiside VII–XII (5–10), as well as eight known triterpene analogues (11–18), were isolated from the aerial parts of Clinopodium chinense (Benth.) O. Kuntze. The structures of the new compounds were determined based on extensive spectral analyses, including 1D (1H and 13C) and 2D NMR experiments (COSY, NOESY, HSQC, 2D TOCSY, HSQC-TOCSY and HMBC), HR-ESI-MS and chemical methods. Compounds 1–18 were evaluated for their protective effects against anoxia/reoxygenation-induced apoptosis in H9c2 cells and cytotoxicities against murine mammary carcinoma cell line 4T1. Compounds 8, 9 and 18 exhibited significant protective effects, while compound 1 exhibited cytotoxic activity with IC50 value of 7.4 μm compared to 7.6 μm for the positive control 10-hydroxycamptothecin.

Prevalence of Spina Bifida Occulta and Its Relationship With Overactive Bladder in Middle-Aged and Elderly Chinese People

Jun Wei Wu,Yu Rong Xing,Yi Bo Wen,Tian Fang Li,Quan De Feng,Xiao Ping Shang,Yun Long Li,Jin Jin Feng,Xin Xin Wang,Rong Qun Zhai,Xiang Fei He,Tao Chen,Xin Jian Liu,Jian Guo Wen 대한배뇨장애요실금학회 2016 International Neurourology Journal Vol.20 No.2

Purpose: To investigate the prevalence of spina bifida occulta (SBO) and its relationship with the presence of overactive bladder (OAB) in middle-aged and elderly people in China. Methods: A cross-sectional community-based survey was carried out at 7 communities in Zhengzhou City, China from December 15, 2013 to June 10, 2014, where residents aged over 40 years were randomly selected to participate. All of the participants underwent lumbosacral radiographic analysis and relevant laboratory tests. A questionnaire including basic information, past medical history and present illness, and the OAB symptom score was filled out by all participants. Chi-square tests and logistic regression were used for data analysis with a P-value of <0.05 denoting statistical significance. Results: A total of 1,061 subjects were qualified for the final statistical analysis (58.8±11.7 years; male, 471 [44.4%]; female, 590 [55.6%]). The overall prevalence of SBO was 15.1% (160 of 1,061): 18.3% (86 of 471) in men and 12.5% (74 of 590) in women. Among these subjects, 13.7% (145 of 1,061) had OAB: 13.2% (62 of 471) in men and 14.1% (83 of 590) in women. The results of logistic regression showed that age, SBO, history of cerebral infarction (HCI), and constipation were risk factors for OAB (P<0.05), while sex, history of childhood enuresis (HCE), body mass index (BMI), and diabetes mellitus (DM) were not (P>0.05). In men, age, SBO, and constipation were risk factors for OAB (P<0.05), while HCE, BMI, DM, HCI, and benign prostate hyperplasia were not (P>0.05). In women, age, SBO, and HCI were risk factors for OAB (P<0.05), while HCE, BMI, DM, vaginal delivery, and constipation were not (P>0.05). Conclusions: The prevalence of SBO is high and it is related to OAB in middle-aged and elderly people in China.

Dysregulated Fatty Acid Metabolism in Hepatocellular Carcinoma

( Ming-da Wang ),( Jun Han ),( Hao Xing ),( Han Zhang ),( Zheng Wang ),( Zhen-li Li ),( Liang Lei ),( Chao Li ),( Feng Shen ),( Tian Yang ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Studies are urgently needed on it molecular pathogenesis and biological characteristics of hepatocellular carcinoma (HCC). Dysregulation of fatty acid (FA) metabolism, in which aberrant activation of oncogenic signaling pathways alters the expression and activity of lipid-metabolizing enzymes, is an emerging hallmark of cancer cells, and it may be involved in HCC development and progression. Methods: We summarize the characteristics of FA metabolism in HCC, focusing on the pathways of FA synthesis, oxidation, uptake and transport. We also provide a brief review of the relationship between NAFLD and HCC development. Results: The current review summarizes the dysregulated FA metabolism in HCC and pathways through which this dysregulation may regulate HCC survival and growth. Aberrant activation of oncogenic signaling pathways regulates the expression and activity of lipid-metabolizing enzymes, thus reprogramming FA metabolism to promote HCC development and progression. Intracellular FAs are required for biosynthesis of most biological membrane lipids and signaling molecules, and are also used to provide energy to support HCCs survival and proliferation, when necessary, through β-oxidation process. HCC cells can employ appropriate metabolic pathways as different situation demands. Intrahepatic cholangiocarcinoma (ICC) and HCC exhibits differential requirement for de novo lipogenesis and distinct response to therapeutic approaches focusing on inhibition of exogenous FA uptake. Non-alcoholic fatty liver disease related obesity and diabetes have increasingly emerged as two major factors responsible for the rise in prevalent of HCC. Conclusions: Our understanding of dysregulated FA metabolism and associated signaling pathways may contribute to the development of novel and efficient anti-tumor approaches for patients with HCC.

Development and Validation of Prealbumin-Bilirubin Score (preALBI Score) for Predicting Long-Term Prognosis after Hepatectomy for Hepatocellular Carcinoma: A Multicenter Analysis versus ALBI Score

( Chao Li ),( Ming-da Wang ),( Hao Xing ),( Lan-qing Yao ),( Yong-kang Diao ),( Li-yang Sun ),( Ya-hao Zhou ),( Feng Shen ),( Dong-sheng Huang ),( Tian Yang ) 대한간학회 2023 춘·추계 학술대회 (The Liver Week) Vol.2023 No.1