• Title/Summary/Keyword: dynamical systems

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KMTNet time-series photometry of the doubly eclipsing candidate stars in the LMC

  • Hong, Kyeongsoo;Lee, Jae Woo;Koo, Jae-Rim;Kim, Seung-Lee;Lee, Chung-Uk;Kim, Dong-Jin
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.1
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    • pp.44.2-44.2
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    • 2017
  • Multiple stellar systems composed of triple, double+double or double+triple, etc. are very rare and interesting objects for understanding the star formation and dynamical evolution. However, only six systems have been found to be a doubly eclipsing quadruple, which consists of two eclipsing binaries, and four systems to be a triply eclipsing hierarchical triple. Recently, the 15 doubly eclipsing multiple candidates located in the Large Magellanic Cloud (LMC) have been reported by the OGLE project. In order to examine whether these candidates are real multiple systems with eclipsing features, we performed a high-cadence time-series photometry for the LMC using the KMTNet (Korea Microlensing Telescope Network) 1.6 m telescopes in three site (CTIO, SAAO, and SSO) during 2016-2017. The KMTNet data will help reveal the photometric properties of the multiple-star candidates. In this paper, we present the VI light curves and their preliminarily analyses for 12 of the 15 eclipsing systems in the LMC, based on our KMTNet observations and the OGLE-III survey data from 2001-2009.

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Formation of Interdependence in Selecting Game

  • Iizuka, Hiroyuki;Yamamoto, Masahito;Kawamura, Hidenori;Suzuki, Keiji;Ohuchi, Azuma
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.80-83
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    • 2000
  • Decision-makers in ecological system and social system have complex interactions and relations. Such interactions and relations are not predefined but dynamically constructed. We consider what relation-s are constructed or destroyed and how the relations change. Therefore, we focus on the formation and collapse of relations as one of the emergent phenomena of social or ecological complex phenomena. Game theory is the best way of analyzing phenomena in terms of interactions. However, it is difficult to analyze the dynamical system by game theory. Consequently, we propose Selecting Game with agents as players based on game theory. In this model, the relations among agents are not predefined but constructed by selecting subgames. As a result, we confirmed that the entire relation among agents is constructed by the agents' changing partial relations and that the relations dynamically change.

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Experimental Studies of Real- Time Decentralized Neural Network Control for an X-Y Table Robot

  • Cho, Hyun-Taek;Kim, Sung-Su;Jung, Seul
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.8 no.3
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    • pp.185-191
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    • 2008
  • In this paper, experimental studies of a neural network (NN) control technique for non-model based position control of the x-y table robot are presented. Decentralized neural networks are used to control each axis of the x-y table robot separately. For an each neural network compensator, an inverse control technique is used. The neural network control technique called the reference compensation technique (RCT) is conceptually different from the existing neural controllers in that the NN controller compensates for uncertainties in the dynamical system by modifying desired trajectories. The back-propagation learning algorithm is developed in a real time DSP board for on-line learning. Practical real time position control experiments are conducted on the x-y table robot. Experimental results of using neural networks show more excellent position tracking than that of when PD controllers are used only.

A MODEL-ORDER REDUCTION METHOD BASED ON KRYLOV SUBSPACES FOR MIMO BILINEAR DYNAMICAL SYSTEMS

  • Lin, Yiqin;Bao, Liang;Wei, Yimin
    • Journal of applied mathematics & informatics
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    • v.25 no.1_2
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    • pp.293-304
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    • 2007
  • In this paper, we present a Krylov subspace based projection method for reduced-order modeling of large scale bilinear multi-input multi-output (MIMO) systems. The reduced-order bilinear system is constructed in such a way that it can match a desired number of moments of multi-variable transfer functions corresponding to the kernels of Volterra series representation of the original system. Numerical examples report the effectiveness of this method.

Ad hoc Network Multicasting Algorithm Based on An Ant System (개미 시스템을 기반으로 한 Ad hoc 네트워크 멀티캐스팅)

  • Kim Joong Hang;Chang Hyeong Soo;Lee Se-young
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.12
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    • pp.1127-1136
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    • 2004
  • This paper proposes a novel multicasting algorithm, called ANMAS (Ad hoc Network Multicasting with Ant System), for Mobile Ad hoc Network (MANET). The algorithm utilizes the indirect communication method of the ants via 'pheromone' to effectively obtain dynamical topology change information, generating safer multicasting paths, and adapts the well-known CBT (Core Based Tree) multicasting algorithm into the ANMAS framework with proper modificiations to make 'tolerable' multicasting group in the MANET environment. We show the efficiency and the effectiveness of ANMAS via simulation studies.

Linearization of nonlinear system by use of volterra kernel

  • Nishiyama, Eiji;Kashiwagi, Hiroshi
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.149-152
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    • 1996
  • In this paper, the authors propose a new method for linearizing a nonlinear dynamical system by use of Volterra kernel of the nonlinear system. The authors have recently obtained a new method for measuring Volterra kernels of nonlinear control systems by use of a pseudo-random M-sequence and correlation technique. In this method, an M-sequence is applied to the nonlinear system and the crosscorrelation function between the input and the output gives us every crosssection of Volterra kernels up to 3rd order. Once we can get Volterra kernels of nonlinear system, we can construct a linearization method of the nonlinear system. Simulation results show good agreement between the observed results and the theoretical considerations.

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Behavior strategies of Soccer Robot using Classifier System (분류자 시스템을 이용한 축구 로봇의 행동 전략)

  • Sim, Kwee-Bo;Kim, Ji-Youn
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.4
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    • pp.289-293
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    • 2002
  • Learning Classifier System (LCS) finds a new rule set using genetic algorithm (GA). In this paper, The Zeroth Level Classifier System (ZCS) is applied to evolving the strategy of a robot soccer simulation game (SimuroSot), which is a state varying dynamical system changed over time, as GBML (Genetic Based Machine Learning) and we show the effectiveness of the proposed scheme through the simulation of robot soccer.

ESTIMATING THE DOMAIN OF ATTRACTION VIA MOMENT MATRICES

  • Li, Chunji;Ryoo, Cheon-Seoung;Li, Ning;Cao, Lili
    • Bulletin of the Korean Mathematical Society
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    • v.46 no.6
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    • pp.1237-1248
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    • 2009
  • The domain of attraction of a nonlinear differential equations is the region of initial points of solution tending to the equilibrium points of the systems as the time going. Determining the domain of attraction is one of the most important problems to investigate nonlinear dynamical systems. In this article, we first present two algorithms to determine the domain of attraction by using the moment matrices. In addition, as an application we consider a class of SIRS infection model and discuss asymptotical stability by Lyapunov method, and also estimate the domain of attraction by using the algorithms.

APPLICATION OF SIMULATED ANNEALING FOR THE MATHEMATICAL MODELLING OF IMMUNE SYSTEMS

  • Lee, Kwon-Soon;Lee, Young-Jin;Chung, Hyeng-Hwan
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.129-132
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    • 1992
  • Cellular kinetics formulate the basis of tumor immune system dynamics which may be synthesized mathematically as cascades of bilinear systems which are connected by nonlinear dynamical terms. In this manner, a foundation for the control of syngeneic tumors is presented. We have analyzed the mechanisms of controlling the infiltration of lymphocytes into tumor tissues. Simulated anneal ins, a general-purpose method of multivariate optimization, is applied to combinatorial optimization, which is to find the minimum of a given function depending on many parameters. We compare the results of the different methods including the global optimization algorithm, known as simutated annealing.

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Topological Analysis of Chaos Characteristics in a Power System

  • Li, Shan-Ying;Lee, Sang-Seung;Park, Jong-Keun
    • KIEE International Transactions on Power Engineering
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    • v.4A no.1
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    • pp.18-25
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    • 2004
  • This paper proposes a totally new method in the chaos characteristics' analysis of power systems, the introduction of topological invariants. Using a return histogram, a bifurcation graph was drawn. As well, the periodic orbits and topological invariants - the local crossing number, relative rotation rates, and linking number during the process of period-doubling bifurcation and chaos were extracted. This study also examined the effect on the topological invariants when the sensitive parameters were varied. In addition, the topological invariants of a three-dimensional embedding of a strange attractor were extracted and the result was compared with those obtained from differential equations. This could be a new approach to state detection and fault diagnosis in dynamical systems.