Automatic Voltage Equalization Circuit Based on Multiple LC Resonant Units for Series-Connected Supercapacitor Strings

Zhang Xiaobing,Zhou Guohua,Liu Shuyi 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

The series-parallel switched-capacitor (SPSC) equalization circuit has high voltage stress on switch. To overcome this problem, an automatic voltage equalization circuit based on multiple LC resonant units is proposed for series-connected supercapacitor strings in this paper. The proposed equalization circuit shortens the equalization paths among cells and uses multiple LC resonant units, which improves the equalization speed. In the proposed equalization circuit, the maximum voltage stress on switch is only half of that in the SPSC equalization circuit. The configuration and operation principle of the proposed equalization circuit is presented. The power, equalization speed, and efficiency of the proposed equalization circuit are analyzed in detail. Based on the theoretical analysis, design considerations of the equalization circuit and design of modularized equalization circuit are proposed to optimize the equalization performance and to further decrease the voltage stress on switch. Simulation and experimental results are provided to verify the validity of the proposed equalization circuit. The results show that the proposed equalization circuit achieves fast equalization speed, high efficiency, and high equalization accuracy.

A New Method of Active Power Measurement Under the Conditions of Distortion Signals Based on Multiple Wavelets

Zhang Xiaobing,Li Hongguang,Cao Wei 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.6

It is discussed that a new method for active power measurement under the conditions of distortion signals. Accurate measurement of the power consumed by the distorted signals has been focused on in recent years due to its practical utilities. In this work, a mathematical description of powers is deducted in the conditions of distorted signals according to a simplified model of the electrical network. Then, a rational measuring method of the electric energy for distorted signals is proposed on the basis of the analysis of the power flow. Also, a measuring method based on multiple wavelets was employed for measuring the active power in the conditions of unsteady distorted signals. Experimental results demonstrate that, by using the simulated typical distorted signals, the proposed measurement method can produce extremely accurate results compared to theoretical results.

Fundamental Frequency Tracking of Distorted Power Signal Based on the Improved EKF Algorithm

Zhang Xiaobing,Yang Mengchen,Yan Yixin,Fang Guozhi 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.10

To reduce the impacts of harmonics and noises on frequency measurements, a novel method of frequency tracking is presented based on improved EKF algorithm and wavelet transform. Firstly, the power signal was preprocessed to extract the fundamental wave by wavelet filtering. Then, an improved Extended Kalman Filter was introduced to achieve fast and accurate frequency tracking. By adding a robust factor and modifying the covariance matrix in real time, it enhanced the stability for detecting distorted signals. The proposed tracking algorithm can effectively solve the problems of traditional Extended Kalman Filter such as lack of adaptability, instability and divergence. And it improved the tracking speed and accuracy. Finally, Detailed simulations on several typical models of power signals have been carried out and the Simulation results shown that the new algorithm increases the speed, convergence and accuracy. It effectively suppresses the impacts of harmonics and noises on the frequency tracking results.

College education and the poor in China: documenting the hurdles to educational attainment and college matriculation

Xiaobing Wang,Chengfang Liu,Linxiu Zhang,Renfu Luo,Thomas Glauben,Yaojiang Shi,Scott Rozelle,Brian Sharbono 서울대학교 교육연구소 2011 Asia Pacific Education Review Vol.12 No.4

Although universities have expanded in size, it is unclear whether the poor have benefited. If there are high returns to college education, then increasing access of the poor to college has important welfare implications. The objective of this paper is to document the rates of enrollment into college of the poor and to identify the hurdles to doing so. Relying on several sets of data, including a survey of college students from universities in three poor provinces in China, we have found that the college matriculation rate of the poor is substantially lower than students from non-poor families; the same is true for rural women and minorities. Clearly, there are barriers that are keeping the rural poor out. The paper also demonstrates that the real hurdles are not during the years of secondary schooling or at the time of admissions to college. The real impediments keeping the rural poor from pursuing a college education arise long before high school-as early as preschool and elementary school years-and are present throughout the entire schooling system.

The Molecular Pathogenesis of Pituitary Adenomas:An Update

Xiaobing Jiang,Xun Zhang 대한내분비학회 2013 Endocrinology and metabolism Vol.28 No.4

Pituitary tumors represent the most common intracranial neoplasms accompanying serious morbidity through mass effects and inappropriate secretion of pituitary hormones. Understanding the etiology of pituitary tumorigenesis will facilitate the development of satisfactory treatment for pituitary adenomas. Although the pathogenesis of pituitary adenomas is largely unknown, considerable evidence indicates that the pituitary tumorigenesis is a complex process involving multiple factors, including genetic and epigenetic changes. This review summarized the recent progress in the study of pituitary tumorigenesis, focusing on the role of tumor suppressor genes, oncogenes and microRNAs.

MODELING AND ANALYZING INDIVIDUAL DRIVER’S STEERING BEHAVIOR BASED ON ROLLING LOCAL-PATH PLANNING DECISION

Chen Xiaobing,Yao Qiang,Zhang Ju 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.2

A good understanding driver behavior is significant in the development of chassis control system and autonomous vehicles. To better simulate human drivers, the driver model with the local path rolling planning decision is developed based on model predictive control algorithm. Firstly, three local path planning methods of straight-line driving, circular-arc driving and B-spline curve driving are designed to describe the different steering styles. Secondly, the linear timevarying (LTV) MPC controller is established to follow the local planned path. Finally, the two typical simulations are carried out and compared with the single-point preview driver model and the optimal preview driver model. And, the results indicate that the proposed driver model is suitable for simulating diversity of the human driver’s driving characteristics.

The complete mitochondrial genomes of Tarsiger cyanurus and Phoenicurus auroreus: a phylogenetic analysis of Passeriformes

Huabin Zhang,Yuze Bai,Xuejia Shi,Linxia Sun,Zhengfei Wang,Xiaobing Wu 한국유전학회 2018 Genes & Genomics Vol.40 No.2

Passeriformes is the largest group within aves and the phylogenetic relationships between Passeriformes have caused major disagreement in ornithology. Particularly, the phylogenetic relationships between muscicapoidea and sylvioidea are complex, and their taxonomic boundaries have not been clearly defined. Our aim was to study the status of two bird species: Tarsiger cyanurus and Phoenicurus auroreus. Furthermore, we analyzed the phylogenetic relationships of Passeriformes. Complete mitochondrial DNA (mtDNA) sequences of both species were determined and the lengths were 16,803 (T. cyanurus) and 16,772 bp (P. auroreus), respectively. Thirteen protein-coding genes, 22 tRNA genes, two rRNA genes, and one control region were identified in these mtDNAs. The contents of A and T at the base compositions was significantly higher than the content of G and C, and this AT skew was positive, while the GC skew was negative. The monophyly of Passeriformes is divided into four major clades: Corvoidea, Sylvioidea, Passeroidea, and Musicicapoidea. Paridae should be separated from the superfamily Sylvioidea and placed within the superfamily Muscicapoidea. The family Muscicapidae and Corvida were paraphyly, while Carduelis and Emberiza were grouped as a sister taxon. The relationships between some species of the order passeriformes may remain difficult to resolve despite an effort to collect additional characters for phylogenetic analysis. Current research of avian phylogeny should focus on adding characters and taxa and use both effectively to obtain a better resolution for deeper and shallow nodes.

Effects of Dietary Flaxseed Lignan Extract on Symptoms of Benign Prostatic Hyperplasia

Wei Zhang,Xiaobing Wang,Yi Liu,Haimei Tian,Brent Flickinger,Mark W. Empie,Sam Z. Sun 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.2

A flaxseed lignan extract containing 33% secoisolariciresinol diglucoside (SDG) was evaluated for its abilityto alleviate lower urinary tract symptoms (LUTS) in 87 subjects with benign prostatic hyperplasia (BPH). A randomized, dou-ble-blind, placebo-controlled clinical trial with repeated measurements was conducted over a 4-month period using treatmentdosages of 0 (placebo), 300, or 600 mg/day SDG. After 4 months of treatment, 78 of the 87 subjects completed the study.For the 0, 300, and 600 mg/day SDG groups, respectively, the International Prostate Symptom Score (IPSS) decreased . 3.67.1.56, . 7.33. 1.18, and . 6.88. 1.43 (mean. SE, P. .100,. .001, and. .001 compared to baseline), the Quality of Lifescore (QOL score) improved by . 0.71. 0.23, . 1.48. 0.24, and . 1.75. 0.25 (mean. SE, P. .163 and .012 comparedto placebo and P. .103,. .001, and. .001 compared to baseline), and the number of subjects whose LUTS grade changedfrom “moderate/severe” to “mild” increased by three, six, and 10 (P. .188, .032, and .012 compared to baseline). Maximumurinary flows insignificantly increased 0.43. 1.57, 1.86. 1.08, and 2.7. 1.93 mL/second (mean. SE, no statistical sig-nificance reached), and postvoiding urine volume decreased insignificantly by . 29.4. 20.46, . 19.2. 16.91, and . 55.62.36.45 mL (mean. SE, no statistical significance reached). Plasma concentrations of secoisolariciresinol (SECO), enterodiol(ED), and enterolactone (EL) were significantly raised after the supplementation. The observed decreases in IPSS and QOLscore were correlated with the concentrations of plasma total lignans, SECO, ED, and EL. In conclusion, dietary flaxseed lig-nan extract appreciably improves LUTS in BPH subjects, and the therapeutic efficacy appeared comparable to that of com-monly used intervention agents of .1A-adrenoceptor blockers and 5.-reductase inhibitors.

Intra Mode Selection for Depth Map Coding in 3D-HEVC

Qiuwen Zhang,Ming Chen,Lixun Huang,Qiliang Zhu,Xiaobing Wang,Yong Gan 한국산학기술학회 2014 SmartCR Vol.4 No.5

3D high efficiency video coding was recently standardized by the Joint Collaborative Team on 3D Video coding as an extension of high efficiency video coding. In the current 3D high efficiency video coding method, new depth intra modes including Depth Modeling Modes and Region Boundary Chain coding are used for depth map coding. These partition-based intra modes achieve the highest possible coding efficiency, but take an extremely long time, which hinders the practical application of the new standard. In this paper, we propose an efficient intra mode selection algorithm for depth map coding in 3D high efficiency video coding. It makes use of the coding information from a spatial neighboring depth map treeblock and the co-located texture video treeblock to predict the depth map intra mode treeblock and terminate its mode decision process early. The experimental results show that the proposed intra mode selection algorithm can achieve the average computational savings of about 40% with a negligible loss of rate distortion performance in 3D high efficiency video coding intra-only configuration.

Research on soil net nitrogen mineralization in Stipa grandis grassland with different stages of degradation

Wanyu Wen,Xiaobing Li,Lihong Chen,Dandan Wei,Han Wang,Meng Zhang,Jing Yu 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.4

Net nitrogen mineralization is one of the nitrogen cycling process, and it is very important to understand nitrogen mineralization characteristics in degradation grassland. In the upper 0–10 cm soil layer of Stipa grandis P. A. Smirn. grassland in the Xilin river basin, Inner Mongolia, we studied the soil net nitrogen mineralization and nitrification among three varying stages of degradation grassland and analyzed the relationship between the mineralization rate of the soil net nitrogen and environmental factors, using the resin-core incubation method. Our results demonstrated that, from May to October 2012, the accumulated net nitrogen mineralization was 21.620 mg kg–1, 12.486 mg kg–1, and 48.053 mg kg–1 in the slightly, medium, and heavily degraded grasslands, respectively and varied greatly among the three stages of degradation shown by the S. grandis grassland plots. During the cultivation period, the variation of net nitrogen mineralization and nitrification was similar to the variation of soil mineral nitrogen. The higher soil mineral nitrogen content indicated higher mineralization of net nitrogen. In July and August, soil moisture was positively correlated with the net nitrogen mineralization rate, and the correlation coefficients between these two factors of 0.73, 0.58, and 0.79 for the slightly, medium, and heavily degraded plots, respectively. The rates of net nitrogen mineralization and nitrification were negatively correlated with soil total nitrogen, but positively correlated with C/N ratio, and weakly correlated with other physicochemical properties.