• Title/Summary/Keyword: Liu system

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Applicability research of round tube CHF mechanistic model in rod bundle channel

  • Liu, Wei;Peng, Shinian;Shan, Jianqiang;Jiang, Guangming;Liu, Yu;Deng, Jian;Hu, Ying
    • Nuclear Engineering and Technology
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    • v.53 no.2
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    • pp.439-445
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    • 2021
  • In view of the complex geometric structure of the rod bundle channel and the limitation of the current CHF visualization experiment technology, it is very difficult to obtain the rod bundle CHF mechanism directly through the phenomenon of the rod bundle CHF visualization experiment. In order to obtain the applicable CHF mechanism assumption for rod bundle channel, firstly, five most representative DNB type round tube CHF mechanistic models are obtained with evaluation and screening. Then these original round tube CHF mechanistic models based on inlet conditions are converted to local conditions and coupled with subchannel analysis code ATHAS. Based on 5 × 5 full-length rod bundle CHF experimental data independently developed by Nuclear Power Institute of China (NPIC), the applicability research of each model for CHF prediction performance in rod bundle channel is carried out, and the commonness and difference of each model are comparatively studied. The CHF mechanism assumption of superheated liquid layer depletion that is most likely to be applicable for the rod bundle channel is selected and two directions that need to be improved are given. This study provides a reference for the development of CHF mechanistic model in rod bundle channel.

Generalized $H^{\infty}$ Control Theory

  • Liu, Kang-Zhi;Mita, Tsutomu
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10b
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    • pp.1539-1544
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    • 1991
  • In this paper we formulate and solve a generalized $H^{\infty}$ control problem. The conventional formulation of $H^{\infty}$ problem has some constraints in application, e.g. it can not deal with the servo problem. This is due to the superfluous requirement of internal stability of the augmented system. In this paper, we alleviate the stability of the augmented system to admit pole-zero cancellation on the imaginary aids outside the feedback loop of G22 and K. After such generalization, the servo problem is naturally incorporated into the $H^{\infty}$ synthesis.is.

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SOME RESULTS ON TOTAL COLORINGS OF PLANAR GRAPHS

  • Hou, Jianfeng;Liu, Guizhen;Xin, Yongxun;Lan, Mei
    • Journal of applied mathematics & informatics
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    • v.26 no.3_4
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    • pp.511-517
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    • 2008
  • Let G be a planar graph. It is proved that if G does not contain a k-cycle with a chord for some k ${\ni}$ {4,5,6}, then G is total-($\Delta(G)+2$)-colorable.

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On the limit cycles of aeroelastic systems with quadratic nonlinearities

  • Chen, Y.M.;Liu, J.K.
    • Structural Engineering and Mechanics
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    • v.30 no.1
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    • pp.67-76
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    • 2008
  • Limit cycle oscillations of a two-dimensional airfoil with quadratic and cubic pitching nonlinearities are investigated. The equivalent stiffness of the pitching stiffness is obtained by combining the linearization and harmonic balance method. With the equivalent stiffness, the equivalent linearization method for nonlinear flutter analysis is generalized to address aeroelastic system with quadratic nonlinearity. Numerical example shows that good approximation of the limit cycle can be obtained by the generalized method. Furthermore, the proposed method is capable of revealing the unsymmetry of the limit cycle; however the ordinary equivalent linearization method fails to do so.

REAL-TIME PERSONAL DOSE MEASUREMENT AND MANAGEMENT SYSTEM RESEARCH IN CHINA

  • Zhang, Z.Y.;Cheng, C.;Liu, Z.S.;Yang, H.T.;Deng, C.M.;Zhang, X.;Guo, Z.J.
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.281-286
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    • 2001
  • The composition and design of a real-time personal dose measurement and management system are described in this paper. Accordingly, some pertinent hardware circuits and software codes including their operation modes have also been presented.

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CIRCULAR LIST COLORINGS OF SOME GRAPHS

  • WANG GUANGHUI;LIU GUIZHEN;YU JIGUO
    • Journal of applied mathematics & informatics
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    • v.20 no.1_2
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    • pp.149-156
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    • 2006
  • The circular list coloring is a circular version of list colorings of graphs. Let $\chi_{c,l}$ denote the circular choosability(or the circular list chromatic number). In this paper, the circular choosability of outer planar graphs and odd wheel is discussed.

EXISTENCE OF PERIODIC SOLUTIONS WITH PRESCRIBED MINIMAL PERIOD FOR A FOURTH ORDER NONLINEAR DIFFERENCE SYSTEM

  • LIU, XIA;ZHOU, TAO;SHI, HAIPING
    • Journal of applied mathematics & informatics
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    • v.36 no.5_6
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    • pp.491-504
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    • 2018
  • In this article, we consider a fourth order nonlinear difference system. By making use of the critical point theory, we obtain some new existence theorems of at least one periodic solution with minimal period. Our main approach used in this article is the variational technique and the Saddle Point Theorem.

Performance Analysis of Water Systems under Hazardous Conditions

  • Liu, Gee-Yu
    • 한국방재학회:학술대회논문집
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    • 2010.02a
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    • pp.10-15
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    • 2010
  • The performance analysis of water systems is very important to urban disaster mitigation. It will benefit the task of preparedness and emergency response through a more practical and more quantitative approach. In this research work, an overview of hydraulics of water system has been provided. A methodology for such implementation based on scenario simulation and hydraulic analysis has been developed. The water system of Taipei Water Department was selected as a test bed for case study. Its serviceability following a major earthquake around Taipei metropolitan area has been quantified.

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Real-Time Two Hands Tracking System

  • Liu, Nianjun;Lovell, Brian C.
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1491-1494
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    • 2002
  • The paper introduces a novel system of two hands real-time tracking based on the unrestricted hand skin segmentation by multi color systems. After corer-based segmentation and pre-processing operation, a label set of regions is created to locate the two hands automatically. By the normalization, template matching is used to find out the left or right hand. An improved fast self-adaptive tracking algorithm is applied and Canny filter is used for hand detection.

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Simulation Analysis of Active Roll Stabilizer for Automotives Based on AMESim

  • Liu, H.;Lee, J.C.;Yo, Y.C.
    • 유공압시스템학회:학술대회논문집
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    • 2010.06a
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    • pp.70-73
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    • 2010
  • In order to provide theoretical analysis for the active roll stabilizer (ARS), the simulation model based on AMESim is developed in the paper. The simplified vehicle rolling motion model is derived firstly, and then the entire ARS control system model is constructed. Furthermore, the simulation is implemented to confirm the roll control effect. The simulation results show that the derived model can be used as theoretical analysis for developing components of ARS control system.

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