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.

Lactoferrin Alleviates the Progression of Atherosclerosis in ApoE−/− Mice Fed with High-Fat/Cholesterol Diet Through Cholesterol Homeostasis

Chen-Jie Ling,Qing-Qing Min,Jin-Rong Yang,Zheng Zhang,Huan-Huan Yang,Jia-Ying Xu,Li-qiang Qin 한국식품영양과학회 2019 Journal of medicinal food Vol.22 No.10

Lactoferrin (LF) is a multifunctional glycoprotein and has beneficial effects on the regulation of lipid metabolism. However, whether LF supplementation alleviates the development of atherosclerosis (AS) remains unclear. In the present study, all of 48 male Apolipoprotein E−/− mice were fed with high-fat diet with 1.25% added cholesterol and divided to four treatment groups with either distilled water (HFCD), LF solutions at 2 mg/mL (low LF), 10 mg/mL (middle LF or MLF), or 20 mg/mL (high LF or HLF) for 12 weeks. Oral glucose tolerance tests (OGTT) were performed at weeks 0, 4, 8, and 12. At the end of the experiment, lipids in serum, liver, and feces were determined. The livers, whole aortas, and aortic sinuses were pathologically examined. The protein expression of factors related to cholesterol synthesis, absorption, and excretion were detected through western blot. No significant difference in body weight, food intake, and OGTT was observed among the four groups. Compared with the HFCD group, the MLF and HLF groups had significantly decreased serum and hepatic cholesterol levels and significantly increased fecal cholesterol contents. LF alleviated the hepatic steatosis and lipid droplet, especially in the MLF group. LF also significantly decreased the average lesion areas in the whole aorta, especially in the MLF group. On the other hand, LF downregulated hepatic protein expression of HMG-CoA reductase (the rate-limiting enzyme in cholesterol synthesis) and upregulated cholesterol 7-alpha hydroxylase (the rate-limiting enzyme in bile acid synthesis from cholesterol). LF also downregulated the intestinal expression of Niemann-Pick C1-like 1 protein, which is known to bind to a critical mediator of cholesterol absorption. In conclusion, LF supplementation alleviates the AS in mice on HFCD likely by reducing the synthesis and absorption of cholesterol and increasing cholesterol excretion.

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

Jie Chen,Quanping Fan,Junhua Wang,Dengpeng Yuan,Lai Wei,Qiangqiang Zhang,Junsheng Liao,Min Xu 한국광학회 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.

Joint Beamforming and Power Allocation Cognitive Radio Networks under Imperfect CSI

Jie Chen,Wen Xi,Xiaolong Sun 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.1

Traditional beamforming and power control algo-rithms in cognitive radio (CR) are based on the assumption of perfect channel state information (CSI) however; this may lead to performance degradation in realistic systems. In this paper, the problem of joint beamforming and power control is investigated in underlay CR networks with imperfect CSI. Our objective is to maximize the sum utility of secondary users (SUs) under the primary users (PUs) interference power constraints and the transmission power constraint of SUs. First, the joint beamforming and power control problem is formulated under game theory framework, where the SUs compete with each other over the beamforming vectors and transmission power level made available by the PUs. Moreover, the channel uncertainty is described using ellipsoid sets and the interference power constraints can be converted into robust interference power constraints. Besides, Nash equilibrium (NE) is considered as the solution of this game. Finally, simulation results show that the proposed scheme can converge to a locally optimal pair of beamforming vector and transmission power level in the presence of channel uncertainty.

A Dual-Population Memetic Algorithm for Minimizing Total Cost of Multi-Mode Resource-Constrained Project Scheduling

Chen, Zhi-Jie,Chyu, Chiuh-Cheng Korean Institute of Industrial Engineers 2010 Industrial Engineeering & Management Systems Vol.9 No.2

Makespan and cost minimization are two important factors in project investment. This paper considers a multi-mode resource-constrained project scheduling problem with the objective of minimizing costs, subject to a deadline constraint. A number of studies have focused on minimizing makespan or resource availability cost with a specified deadline. This problem assumes a fixed cost for the availability of each renewable resource per period, and the project cost to be minimized is the sum of the variable cost associated with the execution mode of each activity. The presented memetic algorithm (MA) consists of three features: (1) a truncated branch and bound heuristic that serves as effective preprocessing in forming the initial population; (2) a strategy that maintains two populations, which respectively store deadline-feasible and infeasible solutions, enabling the MA to explore quality solutions in a broader resource-feasible space; (3) a repair-and-improvement local search scheme that refines each offspring and updates the two populations. The MA is tested via ProGen generated instances with problem sizes of 18, 20, and 30. The experimental results indicate that the MA performs exceptionally well in both effectiveness and efficiency using the optimal solutions or the current best solutions for the comparison standard.

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.

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.

Use of an Artificial Neural Network to Construct a Model of Predicting Deep Fungal Infection in Lung Cancer Patients

Chen, Jian,Chen, Jie,Ding, Hong-Yan,Pan, Qin-Shi,Hong, Wan-Dong,Xu, Gang,Yu, Fang-You,Wang, Yu-Min Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

Background: The statistical methods to analyze and predict the related dangerous factors of deep fungal infection in lung cancer patients were several, such as logic regression analysis, meta-analysis, multivariate Cox proportional hazards model analysis, retrospective analysis, and so on, but the results are inconsistent. Materials and Methods: A total of 696 patients with lung cancer were enrolled. The factors were compared employing Student's t-test or the Mann-Whitney test or the Chi-square test and variables that were significantly related to the presence of deep fungal infection selected as candidates for input into the final artificial neural network analysis (ANN) model. The receiver operating characteristic (ROC) and area under curve (AUC) were used to evaluate the performance of the artificial neural network (ANN) model and logistic regression (LR) model. Results: The prevalence of deep fungal infection from lung cancer in this entire study population was 32.04%(223/696), deep fungal infections occur in sputum specimens 44.05%(200/454). The ratio of candida albicans was 86.99% (194/223) in the total fungi. It was demonstrated that older (${\geq}65$ years), use of antibiotics, low serum albumin concentrations (${\leq}37.18g/L$), radiotherapy, surgery, low hemoglobin hyperlipidemia (${\leq}93.67g/L$), long time of hospitalization (${\geq}14$days) were apt to deep fungal infection and the ANN model consisted of the seven factors. The AUC of ANN model($0.829{\pm}0.019$)was higher than that of LR model ($0.756{\pm}0.021$). Conclusions: The artificial neural network model with variables consisting of age, use of antibiotics, serum albumin concentrations, received radiotherapy, received surgery, hemoglobin, time of hospitalization should be useful for predicting the deep fungal infection in lung cancer.

Route Selection Strategy Combined with Spectrum Characteristic in Cognitive Radio Networks

Jie Chen,Shaoqian Li,Shoufeng Deng 보안공학연구지원센터 2008 International Journal of Software Engineering and Vol.2 No.2

This paper studies route selection strategy combined with spectrum characteristic in decentralized cognitive radio network. The problem is explored from two aspects: the path stability under spectrum characteristic and interference. Especially, a method that measures the interference to primary users is designed. Under this measurement method, the route selection criteria are explored based on spectrum characteristic. Theoretical analysis and numerical results shows these criteria considering interference is better than random selection.