• Title, Summary, Keyword: Hunan

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Novel Control Method for a Hybrid Active Power Filter with Injection Circuit Using a Hybrid Fuzzy Controller

  • Chau, MinhThuyen;Luo, An;Shuai, Zhikang;Ma, Fujun;Xie, Ning;Chau, VanBao
    • Journal of Power Electronics
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    • v.12 no.5
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    • pp.800-812
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    • 2012
  • This paper analyses the mathematical model and control strategies of a Hybrid Active Power Filter with Injection Circuit (IHAPF). The control strategy based on the load harmonic current detection is selected. A novel control method for a IHAPF, which is based on the analyzed control mathematical model, is proposed. It consists of two closed-control loops. The upper closed-control loop consists of a single fuzzy logic controller and the IHAPF model, while the lower closed-control loop is composed of an Adaptive Network based Fuzzy Inference System (ANFIS) controller, a Neural Generalized Predictive (NGP) regulator and the IHAPF model. The purpose of the lower closed-control loop is to improve the performance of the upper closed-control loop. When compared to other control methods, the simulation and experimental results show that the proposed control method has the advantages of a shorter response time, good online control and very effective harmonics reduction.

Chemical Constituents from Leaves of Pileostegia viburnoides Hook.f.et Thoms

  • Li, Xiao Jun;Liu, Zu Zhen;Kim, Kwan-Woo;Wang, Xiang;Li, Zhi;Kim, Youn-Chul;Yook, Chang Soo;Liu, Xiang Qian
    • Natural Product Sciences
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    • v.22 no.3
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    • pp.154-161
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    • 2016
  • Phytochemical investigation on the leaves of Pileostegia viburnoides Hook.f.et Thoms led to the isolation of twenty-five compounds, and their structures were identified as n-dotriacontane (1), taraxeryl acetate (2), friedelin (3), epifriedelinol (4), canophyllal (5), stigmast-4-en-3-one (6), stigmasterol (7), (24R)-5A-stigmastane-3,6-dione (8), ursolic acid (9), pomolic acid (10), umbelliferone (11), 4-epifriedelin (12), n-octatriacontanol (13), ${\beta}$-amyrin (14), ${\alpha}$-amyrin (15), taraxerol (16), nonadecanol (17), friedelane (18), arachic acid (19), protocatechuic acid (20), n-pentatriacontanol (21), hexadecanoic acid (22), vincosamide (23), daucosterol (24), and skimming (25), respectively. To our best knowledge, compounds 1, 2, 12, 13, 17 - 19 and 21-23 were new within Saxifragaceae family. Compounds 15, 16, and 20 were produced from this genus for the first time. Compounds 4, 14 and 25 were first obtained from species P. viburnoides and compounds 3, 5 - 11, and 24 were achieved from the leaves of P. viburnoides for the first time. Furthermore, the anti-neuroinflammatory activity of these isolates was evaluated.

A New Species of the Genus Xysticus (Araneae: Thomisidae) from China

  • Peng, Xian-Jin;Yin, Chang-Min;Kim, Joo-Pil
    • Animal cells and systems
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    • v.4 no.3
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    • pp.263-265
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    • 2000
  • A new species, Xysticus jiangi n. sp. is described based on the specimens collected in Hunan province, China. X. jiangi is similar to X. chui, but distinguished by smaller spermathecae, distinct copulatory canals, and Y-shaped median apophysis. In addition, basal apophysis of tegulum is well developed, compared to that of the latter.

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THE SOLVABILITY CONDITIONS FOR A CLASS OF CONSTRAINED INVERSE EIGENVALUE PROBLEM OF ANTISYMMETRIC MATRICES

  • PAN XIAO-PING;HU XI-YAN;ZHANG LEI
    • Journal of the Korean Mathematical Society
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    • v.43 no.1
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    • pp.87-98
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    • 2006
  • In this paper, a class of constrained inverse eigenvalue problem for antisymmetric matrices and their optimal approximation problem are considered. Some sufficient and necessary conditions of the solvability for the inverse eigenvalue problem are given. A general representation of the solution is presented for a solvable case. Furthermore, an expression of the solution for the optimal approximation problem is given.

SPECTRAL RADIUS OF BIORTHOGONAL WAVELETS WITH ITS APPLICATION

  • Zou, Qingyun;Wang, Guoqiu;Yang, Mengyun
    • Journal of the Korean Mathematical Society
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    • v.51 no.5
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    • pp.941-953
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    • 2014
  • In this paper, a 2-circular matrix theory is developed, and a concept of spectral radius for biorthogonal wavelet is introduced. We propose a novel design method by minimizing the spectral radius and obtain a wavelet which has better performance than the famous 9-7 wavelet in terms of image compression coding.

Enhanced Distance Dynamics Model for Community Detection via Ego-Leader

  • Cai, LiJun;Zhang, Jing;Chen, Lei;He, TingQin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.5
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    • pp.2142-2161
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    • 2018
  • Distance dynamics model is an excellent model for uncovering the community structure of a complex network. However, the model has poor robustness. To improve the robustness, we design an enhanced distance dynamics model based on Ego-Leader and propose a corresponding community detection algorithm, called E-Attractor. The main contributions of E-Attractor are as follows. First, to get rid of sensitive parameter ${\lambda}$, Ego-Leader is introduced into the distance dynamics model to determine the influence of an exclusive neighbor on the distance. Second, based on top-k Ego-Leader, we design an enhanced distance dynamics model. In contrast to the traditional model, enhanced model has better robustness for all networks. Extensive experiments show that E-Attractor has good performance relative to several state-of-the-art algorithms.

Two New Species and Two Unrecorded Species of the Family Salticidae (Arachnida:Araneae) from China (중국산 깡충거미과(거미강:거미목)의 2신종과 2말기록종)

  • 팽금현;공인서;김주필
    • The Korean Journal of Soil Zoology
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    • v.5 no.1
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    • pp.13-19
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    • 2000
  • This paper deals with four species of jumping spiders from Hunan province, China. Two new species; Philaeus daoxianensis sp. n. and Simaetha gongi sp. n., two new ones to China; Neon ningyo and Tasa davidi. Diagnostic structures, such as body and genitalia organs, are illustrated to each species. Descriptions and known data of geographical distribution also are given. In addition, detailed comparisons of the new species and its similar species are discussed. Type specimens are deposited in Department of Biology, Hunan Normal University, Changsha, Hunan, China.

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Arabidopsis AMY1 expressions and early flowering mutant phenotype

  • Jie, Wang;Dashi, Yu;XinHong, Guo;Xuanming, Liu
    • BMB Reports
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    • v.42 no.2
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    • pp.101-105
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    • 2009
  • The homozygous T-DNA mutant of the AMY1 gene in Arabidopsis was identified and importantly, shown to cause an early flowering phenotype. We found that the disruption of AMY1 enhanced expression of CO and FT. The expression analyses of genes related to starch metabolism revealed that expression of the AGPase small subunit APS1 in the wild type was higher than in the amy1 mutant. However, there were no significant differences in expression levels of the AGPase large subunit genes ApL1, AMY2, or AMY3 between wild type and the amy1 mutant. Expression profiling showed that AMY1 was highly expressed in leaves, stems, and flowers, and expressed less in leafstalks and roots. Furthermore, the level of AMY1 mRNA was highly elevated with age and in senescing leaves. RT-PCR analyses showed that the expression of AMY1 was induced by heat shock, GA, and ABA, while salt stress had no apparent effect on its expression.

Nonlinear analysis of finite beam resting on Winkler foundation with consideration of beam-soil interface resistance effect

  • Zhang, L.;Zhao, M.H.;Xiao, Y.;Ma, B.H.
    • Structural Engineering and Mechanics
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    • v.38 no.5
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    • pp.573-592
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    • 2011
  • Comprehensive and accurate analysis of a finite foundation beam is a challenging engineering problem and an important subject in foundation design. One of the limitation of the traditional Winkler elastic foundation model is that the model neglects the effect of the interface resistance between the beam and the underneath foundation soil. By taking the beam-soil interface resistance into account, a deformation governing differential equation for a finite beam resting on the Winkler elastic foundation is developed. The coupling effect between vertical and horizontal displacements is also considered in the presented method. Using Galerkin method, semi-analytical solutions for vertical and horizontal displacements, axial force, shear force and bending moment of the beam under symmetric loads are presented. The influences of the interface resistance on the behavior of foundation beam are also investigated.

An empirical model for amplitude prediction on VIV-galloping instability of rectangular cylinders

  • Niu, Huawei;Zhou, Shuai;Chen, Zhengqing;Hua, Xugang
    • Wind and Structures
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    • v.21 no.1
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    • pp.85-103
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    • 2015
  • Aerodynamic forces of vortex-induced vibration and galloping are going to be coupled when their onset velocities are close to each other, which will induce the cross-wind amplitudes of the structures increased continuously with ever-increasing wind velocities. The main purpose of the present work is going to propose an empirical formula to predict the response amplitude of VIV-galloping interaction. Firstly, two typical mathematical models for the coupled oscillations, i.e., Tamura & Shimada model and Parkinson & Corless model are comparatively summarized. Then, the key parameter affecting response amplitude is determined through comparative numerical simulations with Tamura & Shimada model. For rectangular cylinders with the side ratio from 0.5 to 2.5, which are actually prone to develop the VIV and galloping induced interaction responses, an empirical amplitude prediction formula is proposed after regression analysis on comprehensively collected experimental data with the predetermined key parameter.