SSCI Mitigation of Series-compensated DFIG Wind Power Plants with Robust Sliding Mode Controller using Feedback Linearization

Li, Penghan,Xiong, Linyun,Wang, Jie,Ma, Meiling,Khan, Muhammad Waseem The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

A robust controller is designed based on feedback linearization and sliding mode control to damp sub-synchronous control interaction (SSCI) in doubly fed induction generator (DFIG) wind power plants (WPPs) interfaced with the grid. A feedback-linearized sliding mode controller (FLSMC) is developed for the rotor-side converter (RSC) through feedback linearization, design of the sliding mode controller, and parameter tuning with the use of particle swarm optimization. A series-compensated 100-MW DFIG WPP is adopted in simulation to evaluate the effectiveness of the designed FLSMC at different compensation degrees and wind speeds. The performance of the designed controller in damping SSCI is compared with proportional-integral controller and conventional sub-synchronous resonance damping controller. Besides the better damping capability, the proposed FLSMC enhances robustness of the system under parameter variations.

ON OSCILLATION OF NONLINEAR SECOND ORDER DIEFFRENTIAL EQUATION WITH DAMPING TERM

Li, Meil,Wang, Miansen,Yan, Jurang 한국전산응용수학회 2003 Journal of applied mathematics & informatics Vol.13 No.1

In this paper we investigate the oscillation of nonlinear differdntial equation with damping term. Some new oscillation criteria for the equation are obtained.

SSCI Mitigation of Series-compensated DFIG Wind Power Plants with Robust Sliding Mode Controller using Feedback Linearization

Penghan Li,Linyun Xiong,Jie Wang,Meiling Ma,Muhammad Waseem Khan 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

A robust controller is designed based on feedback linearization and sliding mode control to damp sub-synchronous control interaction (SSCI) in doubly fed induction generator (DFIG) wind power plants (WPPs) interfaced with the grid. A feedback-linearized sliding mode controller (FLSMC) is developed for the rotor-side converter (RSC) through feedback linearization, design of the sliding mode controller, and parameter tuning with the use of particle swarm optimization. A series-compensated 100-MW DFIG WPP is adopted in simulation to evaluate the effectiveness of the designed FLSMC at different compensation degrees and wind speeds. The performance of the designed controller in damping SSCI is compared with proportional-integral controller and conventional sub-synchronous resonance damping controller. Besides the better damping capability, the proposed FLSMC enhances robustness of the system under parameter variations.

Experimental and Numerical Investigation of Stress Concentration Factor of Cable Steel Wire with Corrosion Pits

Rou Li,Changqing Miao,Meiling Zhuang 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.5

Fatigue crack initiates from corrosion pits in various metallic structures, leads to the decline of the fatigue life. In the present study, the effects of the width, depth, angle and spacing of primary and secondary pits on failure mechanism and stress concentration factor are investigated by the experimental and numerical analysis. The results show that depth-width ratio of corrosion pits is the critical factor that affects the dangerous area and stress concentration factor. The development of secondary pits will lead to the multiplier effect of stress concentration factor. The maximum stress is basically located at the mouth or middle part of secondary pits. In addition, the pit angle does not change the distribution of dangerous area, but with the pits angle increasing, the stress concentration factor increases as a whole. The contours that classical butterfly-like distribution rotates and the rotation angle is basically the same with that of the corrosion pits. Furthermore, with the pits spacing increasing, the stress concentration factor increases gradually and converges to the fixed value, which is equal to the stress concentration factor under the single pit. Finally, the relationship between the pits parameters and stress concentration factor is systematically predicted.

Robust Image Watermarking via Perceptual Structural Regularity-based JND Model

( Chunxing Wang ),( Meiling Xu ),( Wenbo Wan ),( Jian Wang ),( Lili Meng ),( Jing Li ),( Jiande Sun ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.2

A better tradeoff between robustness and invisibility will be realized by using the just noticeable (JND) model into the quantization-based watermarking scheme. The JND model is usually used to describe the perception characteristics of human visual systems (HVS). According to the research of cognitive science, HVS can adaptively extract the structure features of an image. However, the existing JND models in the watermarking scheme do not consider the structure features. Therefore, a novel JND model is proposed , which includes three aspects: contrast sensitivity function, luminance adaptation, and contrast masking (CM). In this model, the CM effect is modeled by analyzing the direction features and texture complexity, which meets the human visual perception characteristics and matches well with the spread transform dither modulation (STDM) watermarking framework by employing a new method to measure edge intensity. Compared with the other existing JND models, the proposed JND model based on structural regularity is more efficient and applicable in the STDM watermarking scheme. In terms of the experimental results, the proposed scheme performs better than the other watermarking scheme based on the existing JND models.

Secure Performance Analysis Based on Maximum Capacity

( Xiuping Zheng ),( Meiling Li ),( Xiaoxia Yang ) 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.6

The physical security layer of industrial wireless sensor networks in the event of an eavesdropping attack has been investigated in this paper. An optimal sensor selection scheme based on the maximum channel capacity is proposed for transmission environments that experience Nakagami fading. Comparing the intercept probabilities of the traditional round robin (TRR) and optimal sensor selection schemes, the system secure performance is analyzed. Simulation results show that the change in the number of sensors and the eavesdropping ratio affect the convergence rate of the intercept probability. Additionally, the proposed optimal selection scheme has a faster convergence rate compared to the TRR scheduling scheme for the same eavesdropping ratio and number of sensors. This observation is also valid when the Nakagami channel is simplified to a Rayleigh channel.

The infertile individual analysis based on whole-exome sequencing in chinese multi-ethnic groups

Zhao Qiongzhen,Li Yanqi,Liang Qi,Zhao Jie,Kang Kai,Hou Meiling,Zhang Xin,Du Renqian,Kong Lingyin,Liang Bo,Huang Weidong 한국유전학회 2023 Genes & Genomics Vol.45 No.4

Background Infertility is a common and rapidly growing health issue around the world. The genetic analysis based on the infertile population is crucial for intervention and treatment. Objective To find candidate gene locus led to azoospermia in Chinese multi-ethnic groups and provide theoretical guidance for the diagnosis of genetic diseases to progressively aggravated infertility patients and sterile offspring with ART. Methods The study based on whole-exome sequencing (WES) was presented for genetic characteristic analysis of multi-ethnics and identification of variants related to infertility in Xinjiang area of China. Results The frequency of pathogenic variants showed significant ethnic differences among four main ethnics in Xinjiang. The population structure analysis confirmed that the Hui was close to the Han population, the Kazak was close to the Uygur population, and there are three ancestry components in the four ethnics. In addition, ten candidate variants potentially regulated azoospermia were detected, and KNTC1 (rs7968222: G > T) was chosen to validate the association. Through the analysis in the valid group, the frequency of rs7968222 (G > T) has a significant difference in the azoospermia population (11.76%, 8/68) and normospermia population (4.63%, 35/756) (P < 0.001). Interestingly, the proportion of people with abnormal follicle-stimulating hormone (FSH) level in the group carrying rs7968222 (G > T) was significantly higher than non-carriers (P < 0.05). Therefore, rs7968222 may regulate spermatogenesis through affecting hormone level. Conclusion Our study establishes the genetics analysis of Northwest China and finds a candidate gene locus KNTC1 (rs7968222: G > T), which is one of the genetic susceptibility factors for male azoospermia.

Investigation on Electrical Enhanced Photocatalysis Polishing of Single-Crystal Silicon Carbide Substrates

Xingjun Gao,Xiang Li,Yan He,Lin Fan,Meiling Tang 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.11

In order to solve the problems of low efficiency, pollution and large damage of existing polishing methods, the electrical enhanced photocatalysis polishing method for single-crystal silicon carbide was proposed in this paper. The recombination of electrons and holes was inhibited by the combined action of applied electric field and chemical trapping agent, so the efficiency of oxidation was improved, and the polishing of silicon carbide with high efficiency and low damage can be achieved. The effects of various parameters such as polishing pressure, polishing speed, polishing pad, abrasive particles and oxygenation of slurry on polishing effect were studied. 0.025 MPa of polishing pressure, 60 r/min of polishing speed, 5 wt% of SiO2 abrasive particles and synthetic fiber polymer polishing pad can provide the higher MRR of 1.18 μm/h and the best surface quality (Ra = 0.348 nm). In addition, it has been proven that UV, optimized pH, types of photocatalysts, electron trapping agent and voltage are necessary factors for the slurry to exhibit strong oxidizing properties. The MRR is mainly determined by both mechanical action (introduced by abrasive particles) and chemical action (introduced by slurry). The above technology can basically meet the requirements of high-efficiency, ultra-smooth and low damage polishing of single-crystal silicon carbide.

최승희 훈련체계의 교육적 발전 양상 : 중국 연변대학교의 사례를 중심으로

김봉선 ( Jin Fengxian ),이미령 ( Li Meiling ) 무용역사기록학회 2021 무용역사기록학 Vol.62 No.-

본 논문은 최승희 훈련체계의 교육적 발전 양상을 고찰하기 위한 연구이다. 최승희의 훈련체계를 기반으로 중국조선족무용을 계승 및 발전하고 있는 중국 연변대학교 조선족무용교육 교재의 현황을 사례로 조선족무용교육 교재의 발전 양상과 교재의 특징을 살펴보는데 연구의 목적이 있다. 연변대학교의 조선족무용교육은 초기에는 최승희 훈련체계를 기반으로 이루어 졌으며, 박용원을 통해 더욱 세분화되고 규범화된 교육체계를 구축하게 되었고 오늘날까지 그 명맥을 계승 및 발전하고 있다. 최승희 훈련체계의 교육적 발전 양상을 고찰하고자 최승희의 훈련체계를 기반으로 한 연변대학교의 조선족무용교육 교재의 발전 양상과 그 특징에 대해 실제로 연변대학 예술학원 무용학과의 조선족 무용교육에 활용되고 있는 영상교재 『조선족무용교재』(2005), 『조선족전통무용 소도구 춤 기본』(2015), 『조선족민속무용교재』(2016)를 중점적으로 살펴보았다. 연구를 토대로 살펴본 연변대학교의 조선족무용교육 교재의 특징은 다음과 같다. 첫째, 최승희 훈련체계의 교육 교재 편성방법을 기반으로 하고 있다. 둘째, 최승희의 훈련체계에서 다루지 않았던 내용까지 포괄적으로 수용하여 풍부한 교육내용으로 교재의 구체화를 이루었다. 셋째, 현재는 여성기본을 위주로 훈련체계가 정립되어 있다. 이와 같이 연변대학교의 조선족무용교육은 최승희 훈련체계를 계승하여 이어감과 동시에 그들만의 시대성을 겸비한 논리적이고 전문화된 과학적인 교육체계를 이루고 있다. 따라서 이처럼 연변대학교의조선족무용교육이 지금의 논리적인 훈련체계를 뒷받침할 수 있는 교육 교재를 구축할 수 있었던 점은 바로 계승과 발전이라는 두 근본을 원칙으로 조선족무용교육을 위해 연구에 헌신한 조선족무용 교육가들이 있었기 때문이다. 이를 계기로 현재까지 이루어낸 모든 교육 교재를 하나의 종합적이고 총체를 이루는 중국 조선족무용교재로 집필하게 된다면 진정한 교육체계의 확립을 이루게 될 것이라 사료된다. 앞으로 연변대학교 조선족무용교육이 오늘날의 성과를 이어 꾸준히 사회적 발전과 수요에 따라 적극적인 변화와 개혁을 통해 더욱더 비약적인 발전을 이룰 것이라 전망해본다. This study aims to examine the educational development of Choi Seunghee’s training system, particularly with a focus on the development patterns of Korean-Chinese dance education textbooks and characteristics of Korean-Chinese dance education textbooks at Yanbian University in China, which has inherited and developed Korean-Chinese dance based on Choi Seunghees training system. The characteristics of Yanbian University’s Korean-Chinese dance education textbooks examined in this study are as follows. First, it is based on the method of organizing educational textbooks, which was identified in Choi Seunghee’s training system. Second, the contents that were not covered by Choi Seunghee’s training system have been comprehensively adopted into the textbooks, which thus came to be loaded with abundant educational content. Third, a training system is currently established focusing on the basics of women’s dance movements. Yanbian University’s Korean-Chinese dance education was able to create educational textbooks that could support the current logical training system due to the Korean-Chinese dance educators’ devotion to research on Korean-Chinese dance education, which was based on the principle of succession and development.

중국 조선족 장고춤의 시대적 변화양상과 안무특성 고찰

박정화 ( Piao Zhenghua ),이미령 ( Li Meiling ) 무용역사기록학회 2020 무용역사기록학 Vol.59 No.-

중국 조선족 장고춤은 조선족에게 있어 상징적 의미가 있는 민족예술이며 조선족 문화의 결정체이다. 본 논문은 한민족의 전통문화인 장고춤이 중국이라는 새로운 환경에서 재맥락화 과정을 통해 중국 조선족 장고춤으로 정착 및 발전하는 과정을 고찰하는데 목적이 있다. 이를 위해 중국 조선족 문화의 계승 및 발전의 토대에서 조선족 장고춤의 시대적 변화양상 및 안무특성을 살펴보았다. 첫째, 중국 조선족 문화의 계승과 발전 차원에서 조선족 무용가들은 민족무용의 발전의 길을 모색하며 중국의 새로운 시각과 새로운 사상에 기초하여 조선족 무용의 발굴, 정리 및 재창조 사업을 추구하였다. 둘째, 중국 조선족 장고춤은 각 시기별 조선족 무용의 변화와 발전된 시대상을 단계적으로 반영하며 발전하였다. 셋째, 조선족 장고춤의 예술적 특성은 무용수의 인체적인 미감(美感)을 강조하며, 무용수의 몸짓과 표현이 장고와 하나가 되어 음악과 함께 완벽한 조화를 이루는데 있다. 이 논문이 조선족 장고춤이 향후 한층 더 발전하는데 기여하기를 바라며, 또한 조선족 무용연구의 기초자료로 활용될 수 있기를 기대한다. The Korean-Chinese Janggo dance is a symbolic national art of the Korean-Chinese and a symbol of the Korean-Chinese culture. This study aims to research how Korean traditional culture, Janggo dance, developed and settled into the Korean-Chinese Janggo dance in China. To this end, we examine the changes of the Korean-Chinese Janggo dance by period and the characteristics of its choreography for the succession and development of the Korean-Chinese culture. First, the Korean-Chinese dancers pursued the development of national dance for succession and development of their culture, and also they attempted projects to discover, organize, and recreate the Korean-Chinese dance based on different perspective and ideas from China. Second, the Korean-Chinese Janggo dance has developed, reflecting the changes and development of The Korean-Chinese Janggo dance by period. Third, the artistic feature of the Korean-Chinese Janggo dance emphasizes the beauty of the dancer's body and expresses the harmony of the dancer's gestures as well as expressions with the Janggo dance and music. We hope that this paper would devote itself to the development of the Korean-Chinese Janggo dance and be used as a basis for future research.