An Improved Method of Maximum Power Point Tracking Strategy for Wind Power Conversion System

CHEN Ran,CHEN Jie,CHEN Jia-wei,CHEN Zhi-hui,GONG Chun-ying,YAN Yang-guang 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

The turbine speed loop adjustment is the key link of the designing of the controller for the fixed pitch variable speed wind energy conversion systems (WECS). Because of the strong nonlinear, big inertia and mechanical damping characteristics, it’s difficult to designing the controller of the wind power systems. In this paper, a small signal model is present, and based on the analyzing; a wind turbine speed loop regulator is designed. Then, a method of tracking the peak power conversion system is proposed, which is independent of the turbine parameters and air density. At last, simulation system is built, and the results of the simulation experiments show that, the performance of the controller algorithm meet the requirements of the MPPT without wind measurement.

Combined Assessment of Serum Alpha-Synuclein and Rab35 is a Better Biomarker for Parkinson’s Disease

Hung-Li Wang,Chin-Song Lu,Tu-Hsueh Yeh,Yu-Ming Shen,Yi-Hsin Weng,Ying-Zu Huang,Rou-Shayn Chen,Yu-Chuan Liu,Yi-Chuan Cheng,Hsiu-Chen Chang,Ying-Ling Chen,Yu-Jie Chen,Yan-Wei Lin,Chia Chen Hsu,Huang-Li 대한신경과학회 2019 Journal of Clinical Neurology Vol.15 No.4

Background and Purpose It is essential to develop a reliable predictive serum biomarker for Parkinson’s disease (PD). Te accumulation of alpha-synuclein (αSyn) and up-regulated expression of Rab35 participate in the etiology of PD. Te purpose of this investigation was to determine whether the combined assessment of serum αSyn and Rab35 is a useful predictive biomarker for PD. Methods Serum levels of αSyn or Rab35 were determined in serum samples from 59 sporadic PD patients, 19 progressive supranuclear palsy (PSP) patients, 20 multiple system atrophy (MSA) patients, and 60 normal controls (NC). Receiver operating characteristics (ROC) curves were calculated to determine the diagnostic accuracy of αSyn or/and Rab35 in discriminating PD patients from NC or atypical parkinsonian patients. Results The levels of αSyn and Rab35 were increased in PD patients. The serum level of Rab35 was positively correlated with that of αSyn in PD patients. Compared to analyzing αSyn or Rab35 alone, the combined analysis of αSyn and Rab35 produced a larger area under the ROC curve and performed better in discriminating PD patients from NC, MSA patients, or PSP patients. When age was dichotomized at 55, 60, 65, or 70 years, the combined assessment of αSyn and Rab35 for classifying PD was better in the group below the cutof age than in the group above the cutof age. Conclusions Combined assessment of serum αSyn and Rab35 is a better biomarker for discriminating PD patients from NC or atypical parkinsonian patients, and is a useful predictive biomarker for younger sporadic PD patients.

Imaging Cell Surface Glycans ofCardiomyocytes in Intact Rat Heart

Jie Rong,Jing Han,Lianshun Feng,Yanhong Tan,Qiwei Wang,Yingying Chen,Shiqiang Wang,Xing Chen 한국당과학회 2012 한국당과학회 학술대회 Vol.2012 No.1

Glycosylation is essential for proper cell signaling and embryonic development. Changes in glycosylation are often a hallmark of disease states. Cardiovascular disease has become one of the top causes of death. Many studies using rat models have related heart diseases and regulations of heart physiological functions to altered glycosylations. However, the dynamic regulation and molecular mechanism of glycosylation in heart are not clear. Rat is an important model organism for human cardiovascular disease studies. Isolated intact rat hearts are often used in physiological and pathological studies. In situ imaging biomolecules in intact heart avoid possible damage of myocyte and biased loss of cardiac myocytes during enzymatic isolation. Here, we applied the metabolic glycan labeling technique for imaging sialylation and O-linked glycosylation in living cardiomyocytes and intact rat hearts. The effects of unnatural sugars on the function of cardiomyocytes and hearts were evaluated. We found unnatural sugars did not perturb the function of cardiomyocytes and hearts. Glycan imaging revealed an interesting distribution pattern: sialic acid or O- linked glycan enriched at intercalated discs of adult rat cardiomyocytes. We also observed that the glycosylations of cardiomyocytes were altered in isoproterenol-induced cardiac hypertrophy rat models. This work extends the application of metabolic glycan labeling technique to probe glycosylations in rats and provides the first example of using this technique for in situ cellular glycans imaging in mammalian model organisms. The biological significance of altered glycosylations in cardiac hypertrophy heart is under investigation in our lab.

Male hypogonadism caused by a homozygous missense mutation of the LHB gene

( Jie Chen ),( Wen-ting Yi ),( Yuan-Qing Cui ),( Wen-ting Wang ),( Xiong Wang ) 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.6

Use of an Artificial Neural Network to Predict Risk Factors of Nosocomial Infection in Lung Cancer Patients

Chen, Jie,Pan, Qin-Shi,Hong, Wan-Dong,Pan, Jingye,Zhang, Wen-Hui,Xu, Gang,Wang, Yu-Min Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Statistical methods to analyze and predict the related risk factors of nosocomial infection in lung cancer patients are various, but the results are inconsistent. A total of 609 patients with lung cancer were enrolled to allow factor comparison using Student's t-test or the Mann-Whitney test or the Chi-square test. Variables that were significantly related to the presence of nosocomial infection were selected as candidates for input into the final ANN model. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the performance of the artificial neural network (ANN) model and logistic regression (LR) model. The prevalence of nosocomial infection from lung cancer in this entire study population was 20.1% (165/609), nosocomial infections occurring in sputum specimens (85.5%), followed by blood (6.73%), urine (6.0%) and pleural effusions (1.82%). It was shown that long term hospitalization (${\geq}22days$, P= 0.000), poor clinical stage (IIIb and IV stage, P=0.002), older age (${\geq}61days$ old, P=0.023), and use the hormones were linked to nosocomial infection and the ANN model consisted of these four factors. The artificial neural network model with variables consisting of age, clinical stage, time of hospitalization, and use of hormones should be useful for predicting nosocomial infection in lung cancer cases.

Simulation of an X-ray Fresnel Zone Plate with Nonideal Factors

Chen, Jie,Fan, Quanping,Wang, Junhua,Yuan, Dengpeng,Wei, Lai,Zhang, Qiangqiang,Liao, Junsheng,Xu, Min Optical Society of Korea 2020 Current Optics and Photonics Vol.4 No.1

Fresnel zone plates have been widely used in many applications, such as x-ray telescopes, microfluorescence, and microimaging. To obtain an x-ray Fresnel zone plate, many fabrication methods, such as electron-beam etching, ion-beam etching and chemical etching, have been developed. Fresnel zone plates fabricated by these methods will inevitably lead to some nonideal factors, which have an impact on the focusing characteristics of the zone plate. In this paper, the influences of these nonideal factors on the focusing characteristics of the zone plate are studied systematically, by numerical simulations based on scalar diffraction theory. The influence of the thickness of a Fresnel zone plate on the absolute focusing efficiency is calculated for a given incident x-ray's wavelength. The diffraction efficiency and size of the focal spot are calculated for different incline angles of the groove. The simulations of zone plates without struts, with regular struts, and with random struts are carried out, to study the effects of struts on the focusing characteristics of a zone plate. When a Fresnel zone plate is used to focus an ultrashort x-ray pulse, the effect of zone-plate structure on the final pulse duration is also discussed.

A Study on Video Remix Creation Using Social Media : Based on the Film Life in a Day Utilizing YouTube Clips

Jie Chen,이현진 한국영상학회 2012 한국영상학회 논문집 Vol.10 No.1

영화와 비디오 아트의 창작방식은 지속적으로 변화하고 있다. 인터넷의 급속한 발전과 함께 오늘날의 영화 제작자들은 아트 작업을 하는데 있어, 더 많은 기회와 선택을 얻게 되었다. 본 논문은 유튜브 클립을 영상제작의 소스로 이용한 최근 비디오 작업에 대한 연구이다. 영화와 비디오 작업에서 유튜브 클립을 이 용한 점은 다양한 의미를 제공한다. 첫째, 직접 촬영하는 대신, 이미 존재하는 재료를 소스로 이용한다. 둘 째, 이런 작업 방식은 주어진 시간 안에 다양한 지역에 있는 참여자들의 정보를 수집 할 수 있게 한다. 단, 이런 작업방식은 더 비판적이고 더 계획적인 편집 테크닉을 필요하게 된다. 유튜브 클립을 이용한 최 근 비디오 리믹스 작업의 의미와 전략을 찾기 위해, 본 논문은 영화의 편집법와 정보 수집법에 대해서 연 구 한다. 편집법에 대해서는 몽타주의 개념, 쿨레쇼프 효과와 몽타주의 새로운 형식이자 같은 주제를 가진 수많은 영상 클립들을 수집하는 작업방식인 '슈퍼컷'에 대해서 논의 하고 정보수집법의 획기적인 면에 대해서는 유튜브를 이용한 크라우드 소싱의 개념을 연구 한다. 이를 위해 본 논문에서 영화 "Life in a Day" 를 주요 연구 자료로 사용하게 된다.

Observed Quasi-steady Kinetics of Yeast Cell Growth and Ethanol Formation under Very High Gravity Fermentation Condition

Chen Li-Jie,Xu Ya-Li,Bai Feng-Wu,Anderson William A.,Murray Moo-Young The Korean Society for Biotechnology and Bioengine 2005 Biotechnology and Bioprocess Engineering Vol.10 No.2

Using a general Saccharomyces cerevisiae as a model strain, continuous ethanol fermentation was carried out in a stirred tank bioreactor with a working volume of 1,500 mL. Three different gravity media containing glucose of 120, 200 and 280 g/L, respectively, supplemented with 5 g/L yeast extract and 3 g/L peptone, were fed into the fermentor at different dilution rates. Although complete steady states developed for low gravity medium containing 120 g/L glucose, quasi-steady states and oscillations of the fermented parameters, including residual glucose, ethanol and biomass were observed when high gravity medium containing 200 g/L glucose and very high gravity medium containing 280 g/L glucose were fed at the designated dilution rate of $0.027\;h^{-1}$. The observed quasi-steady states that incorporated these steady states, quasi-steady states and oscillations were proposed as these oscillations were of relatively short periods of time and their averages fluctuated up and down almost symmetrically. The continuous kinetic models that combined both the substrate and product inhibitions were developed and correlated for these observed quasi-steady states.

PRESCHOOL EDUCATION IN CHINA : A CRITICAL REVIEW OF ITS SOCIAL CONTEXT,VALUES,AND PRACTICES

Chen, Jie-Qi EAST WEST EDUCATION RESEARCH INSTITUTE EWHA WOMANS 1991 East west education Vol.12 No.-

Ki-67 is a Valuable Prognostic Factor in Gliomas: Evidence from a Systematic Review and Meta-analysis

Chen, Wen-Jie,He, De-Shen,Tang, Rui-Xue,Ren, Fang-Hui,Chen, Gang Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Ki-67 has been widely used as an indicator of cell proliferation in gliomas. However, the role of Ki-67 as a prognostic marker is still undefined. Thus, we conducted a meta-analysis of the published literatures in order to clarify the impact of Ki-67 on survival in glioma cases. Eligible studies were identified in PubMed, EMBASE, ISI Web of Science, Cochrane Central Register of Controlled Trials, Science Direct and Wiley Online Library with the last search updated on August 31, 2014. The clinical characteristics, overall survival (OS) and progression-free survival (PFS) together with Ki-67 expression at different time points were extracted. A total of 51 studies, covering 4,307 patients, were included in the current meta-analysis. The results showed that overexpression of Ki-67 can predict poor OS (HR=1.66, 95%CI: 1.53-1.80; Z=11.87; p=0.000) and poor PFS (HR=1.67, 95%CI: 1.47-1.91; Z=7.67; p=0.000) in gliomas. Moreover, subgroup analyses also indicated that high level of Ki-67 expression was related to poor OS and PFS in glioma patients regardless of region, pathology type, cut-off value and statistical method. In conclusion, the current meta-analysis revealed that Ki-67 expression might be a predicative factor for poor prognosis of glioma patients, emphasizing its importance as a predictor.