• International Journal of Fuzzy Logic and Intelligent Systems
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• v.15 no.3
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• pp.166-171
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• 2015

In this paper, we measure the current and vibration signals of one-dimensional time series that occur in a motor and pump, respectively. These machines are representative rotary and pumping machines. We also eliminate unnecessary components such as noise by pre-processing the current and vibration signals. Then, in order to diagnose fault signals for the pump and motor, we transform from one-dimensional time series to a two-dimensional phase portrait using Takens’ embedding method. After this transformation, we review the variation in the pattern according to the fault signals.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.3
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• pp.269-276
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• 2011

This paper proposes a novel control method using phase plane for a hydraulic biped humanoid robot. In biped walking control, it is much more difficult to control the posture of a biped robot in the coronal plane because the supporting area formed by the both feet in the coronal plane is much narrower than that of the sagittal plane. When the biped robot walks stably, the phase portrait of the pelvis in the coronal plane makes an elliptical shape. From this point of view, we develop an ankle torque controller and a foot placement controller for tracking the desired phase portrait during walking. We design these controllers by using simulations of a simplified compass gait biped model to regulate the desired phase portrait of pelvis. The effectiveness of the proposed control method is proved through full-body dynamic walking simulations and real experiments of the SARCOS hydraulic biped humanoid.

• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.73-83
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• 1998

Considering dynamic behaviors according to initial tension forces, geometric nonlinearity and the effect of higher eigen modes to participate in dynamic behaviors increase as initial tension forces decrease, and from phase portrait we can realize that period attractors are produced in many area with complexity. If initial tension forxes increase, difference between linear and nonlinear solutions will decrease and the first eigen mode dominate the dynamic behaviors and observing phase portrait, period attractors appear in certain area regularly. These results may offer meaningful informations to nonlinear dynamic analysis using modal reduction methods such as Lanczos modal analysis. And actually nonlinear dynamic analysis needs very large computational efforts. So, if we determine the number of eigen modes to take part in modal analysis corresponding to initial tension forces we will get more accurate data close to exact nonlinear dynamic solutions.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1441-1446
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• 2014

Love which is one of the emotional of mankind, has been studied in sociology and psychology as a matter of grate concern. In this paper we propose a modified romantic behaviors by using basic the love equation of Romeo and Juliet. We represent the behaviors using time series and phase portrait when we vary the parameter in the modified love equation. Also we analyze the behavior's relation by using time series and phase portraits when external force applied as the third person between Romeo and Juliet.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.11
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• pp.1691-1696
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• 2013

In this paper, an analysis of behavior is performed in the circular hybrid energy harvesting device. This analysis of behavior is to confirm with or without an existence of nonlinear system because its system is required to produce the more energy. To do this, first of all the phase portrait is reconstructed through Taken's embedding method, and then Poincare map is organized by using phase portrait and finally Lyapunov exponent is analyzed.

• The Pure and Applied Mathematics
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• v.6 no.2
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• pp.67-77
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• 1999

In this paper we study periodic orbit of some planar control systems and investigate phase portraits of the FSs.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.81-86
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• 2016

Three hundred years ago, the fractional differential equation that is one of concept of fractional calculus released. Now, many researchers continue to try best effort applying into the control engineering, mathematics and physics. In this paper, the dynamics equation which is represented by Van der Pol, represent integer order and fractional order that having real order. Then this paper performs the comparisons between integer and real order as time series and phase portrait according to variation of parameter value for real order.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.277-280
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• 1995

This paper describes a real time QRS detection algorithm. The proposed algorithm detects QRS complex using characteristics of the 2-dimensional phase portrait which is reconstructed from 1-demensional scalar time series. We observe the phase portrait of ECG signal has special trejectory when QRS complex occurs and apply it to detect QRS complexes. In order to evaluate the performance of the proposed algorithm, we use MIT/BIH arrhythmia database. As a result, the proposed algorithm correctly detects 99.3% of the QRS complexes.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.12
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• pp.1389-1394
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• 2015

Recently many effort appears applying the concept of fractional calculus that can be represented by fractional differential equation in the control engineering, physics and mathematics. This paper describes the fractional order with real order for Duffing equation which can be represented by integer order. This paper also confirms the existence of chaotic behaviors by using time series and phase portrait with varying the parameter of real order.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.6
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• pp.645-652
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• 2016

The basic equation of body and mind that can be represented as body and mind based on love model of Romeo and Juliet is presented in this paper. In order verify validity for physical idea of unification for body and mind when the external force is applied in the basic equation. We display the time series and phase portrait for nonlinear behavior, and this paper confirms the point of difference between body-mind neutral monism and body-mind dualism.