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Abnormal State Detection of OLTC Based on Improved Fuzzy C-means Clustering

Chinese Journal of Electrical Engineering 2023年第1期9卷 129-141页

作者： Hongwei Li lilong dou Shuaibing Li Yongqiang Kang Xingzu Yang Haiying Dong School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou 730070China School of New Energy and Power Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

An accurate extraction of vibration signal characteristics of an on-load tap changer(OLTC)during contact switching can effectively help detect its abnormal ***,an improved fuzzy C-means clustering method for abnormal state detection of the OLTC contact is ***,the wavelet packet and singular spectrum analysis are used to denoise the vibration signal generated by the moving and static contacts of the ***,the Hilbert-Huang transform that is optimized by the ensemble empirical mode decomposition(EEMD)is used to decompose the vibration signal and extract the boundary spectrum ***,the gray wolf algorithm-based fuzzy C-means clustering is used to denoise the signal and determine the abnormal states of the OLTC *** analysis of the experimental data shows that the proposed secondary denoising method has a better denoising effect compared to the single denoising *** EEMD can improve the modal aliasing effect,and the improved fuzzy C-means clustering can effectively identify the abnormal state of the OLTC *** analysis results of field measured data further verify the effectiveness of the proposed method and provide a reference for the abnormal state detection of the OLTC.

关键词： On-load tap changer singular spectrum analysis Hilbert-Huang transform gray wolf optimization algorithm fuzzy C-means clustering

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Establishing a human pancreatic stem cell line and transplanting induced pancreatic islets to reverse experimental diabetes in rats

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Science China(Life Sciences) 2008年第9期51卷 779-788页

作者： XIAO Mei AN lilong YANG XueYi GE Xin QIAO Hai ZHAO Ting MA XiaoFei FAN JingZhuang ZHU MengYang dou ZhongYing Department of Animal Medicine Agricultural CollegeGuangdong Ocean UniversityZhanjiang 524088China Shaanxi Branch of National Stem Cells Engineering and Technology Centre Northwest Sci-Tech University of Agriculture and ForestryYangling 712100China Department of Pharmacology Quillen College of MedicineEast Tennessee State UniversityJohnson CityTN 37614USA

The major obstacle in using pancreatic islet transplantation to cure type I and some type II diabetes is the shortage of the donors. One of ways to overcome such obstacle is to isolate and clone pancreatic stem cells as "seed cells" and induce their differentiation into functional islets as an abundant trans-plantation source. In this study, a monoclonal human pancreatic stem cell (mhPSC) line was obtained from abortive fetal pancreatic tissues. Pancreatic tissues were taken from abortive fetus by sterile procedures, and digested into single cells and cell clusters with 0.1% type IV collagenase. Cultured in modified glucose-low DMEM with 10% fetal bovine serum (FBS), these single cells and cell clusters adhered to culture dishes, and then primary epidermal-like pancreatic stem cells started to clone. After digesting with 0.25% trypsin and 0.04% EDTA, fibroblasts and other cells were gradually eliminated and epithelioid pancreatic stem cells were gradually purified during generations. Using clone-ring selection, the mhPSCs were obtained. After addition of 10 ng/mL epidermal growth factor (EGF) in cell culture medium, the mhPSCs quickly grew and formed a gravelstone-like monolayer. Continuously proliferated, a mhPSC line, which was derived from a male abortive fetus of 4 months old, has been passed through 50 generations. More than 1×109 mhPSCs were cryo-preserved in liquid nitrogen. Karyotype analysis showed that the chromosome set of the mhPSC line was normal diploid. Immunocytochemistry results demonstrated that the mhPSC line was positive for the pdx1, glucagon, nestin and CK19, and negative for the insulin, CD34, CD44 and CD45 protein expression. RT-PCR revealed further that the mhPSCs expressed transcription factors of the pdx1, glucagon, nestin and CK19. Also, in vitro induced with β-mercaptoethanol, the mhPSCs differentiated into nerve cells that expressed the NF protein. Induced with nicotinamide, the mhPSCs differentiated into functional islet-like clusters,

关键词： pancreatic stem cell mono-clone differentiation transplantation human

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测量学课程改革与实践

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测绘通报 2020年第5期 146-149页

作者：王浩宇任超刘立龙梁月吉卢献健窦世卿高二涛桂林理工大学测绘地理信息学院广西桂林541004

教育改革的核心问题是课程的改革,教育改革只有进入到课堂的层面,才是真正进入了教育改革的深水区。本文以测量学课程改革为立足点,对测量学课程改革的持续建设进行了总结,提出并不断丰富"一中心,三育人"课程教学理念;深化教学资源改革... 详细信息

教育改革的核心问题是课程的改革,教育改革只有进入到课堂的层面,才是真正进入了教育改革的深水区。本文以测量学课程改革为立足点,对测量学课程改革的持续建设进行了总结,提出并不断丰富"一中心,三育人"课程教学理念;深化教学资源改革,构建了一种长效的"多主体、全过程、可量化"课程发展机制;教学相长,实现了"重素质、强能力、多元开放"的测量学课程教学。

关键词：测量学课程教学改革理念机制

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