• Proceedings of the KIEE Conference
• /
• 2008.04a
• /
• pp.207-208
• /
• 2008

This paper presents a robust state observer design for a class of Lipschitz nonlinear systems with time delay and external disturbance. A sufficient conditions on the existence of the proposed observer are characterized by linear matrix inequalities. It is also shown that the proposed observer design can reduce the effect on the estimation error of external disturbance up to the prescribed level in spite of the existence of time delay. Finally, a numerical example is provided to verify the proposed design method.

• Proceedings of the KWS Conference
• /
• 1997.05a
• /
• pp.107-111
• /
• 1997

In this paper distribution of welding residual stress on the double fillet welded joint which exits and not exits root gap, i.e. full penetration and partial penetration is investigated by two dimensional cunduct and thermal elasto-plastic analysis. And stress distribution on notch-tip of the structure where welding residual stress regarded as initial stress and then external load is added is also investigated.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.8
• /
• pp.837-841
• /
• 2008

This paper presents a robust reduced order state observer for a class of Lipschitz nonlinear systems with external disturbance. Sufficient conditions on the existence of the proposed observer are characterized by linear matrix inequalities. It is also shown that the proposed observer design can reduce the effect on the estimation error of external disturbance up to the prescribed level. Finally, a numerical example is provided to verify the proposed design method.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2000.02a
• /
• pp.26-28
• /
• 2000

Generally high frequency electromagnetic waves can not penetrate into waveguide, and it is called skin effect. Since the shape of superconducting CICC (Cabel In Conduit Conductor) is similar to that of waveguide, the characteristics of waveguide can be applied to CICC. In this paper, we analyzed penetrated magnetic field in CICC according to external noise. From it, noise frequency bandwidth affecting voltage tap sensor in CICC was found.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.02a
• /
• pp.137-139
• /
• 2003

The relationship between magnetic properties of BiPbSrCaCuO superconductor and externally applied magnetic field was studied to develop a magnetic field polarity sensor. The behavior was related to the magnetic flux trapped in the superconductor, which penetrates through the material by the external magnetic field. Some portion of the superconductor was changed to a normal state by the trapped magnetic flux. Electrical characteristics of the superconductor with trapped magnetic flux were extremely sensitive to the external magnetic field and showed different responses depending on the direction of the magnetic field.

• Proceedings of the KIEE Conference
• /
• 1997.07b
• /
• pp.612-615
• /
• 1997

In this paper, a robust speed controller considering the effect of uncertainty (plant parameter variation. external load disturbance. unmodeled and nonlinear dynamics etc..) for induction motor is proposed. Firstly. the dynamic model at nominal case of induction motor is estimated. Based on the estimated model. the IPSC ( Integral - Proportional Speed Controller) is designed. Then a DTRC (Dead-time Robust Controller) combining DTC ( Dead-time Compensator) & SRC (Simple Robust Controller) is designed to reduce the effects of parameter variation and external disturbance. Some simulated results are provided to demonstrate the effectiveness of the proposed controller.

• Journal of the Optical Society of Korea
• /
• v.12 no.3
• /
• pp.152-156
• /
• 2008

This paper reports a fiber-optic temperature sensor using a single mode fused fiber coupler incorporating a thermo-optic external medium. The spectral transmission was altered by changing the refractive index of the external thermo-optic medium. A theoretical and experimental investigation was carried out with the aim of achieving high sensitivity. The measured sensitivity for the environmental temperature was as high as -1.5 $nm/^{\circ}C$.

• Journal of the Optical Society of Korea
• /
• v.6 no.2
• /
• pp.33-36
• /
• 2002

We propose a modulation scheme of optical absorption in a coupled asymmetric quantum well (QW) structure via electrically controllable quantum interference. It is based on the parallel-perpendicular energy coupling effect. We show that by applying an external electric Held in the parallel direction (to the QW layers), we can obtain a maximum (peak-type) absorption at a specific wavelength where absorption cancellation would occur due to electrically induced transparency without such an external Held .

• 재활복지
• /
• v.22 no.3
• /
• pp.145-168
• /
• 2018

The purpose of this study is to analyze the effect of disability acceptance mediated with policy trust on the life satisfaction and group difference of disability type. For this purpose, the raw data(2nd wave, 2st survey) of Panel Survey of Employment for the Disabled(PSED) conducted by the Korea Employment for the Disabled were used. Among the respondents, the data of 2,378 of the external physical disabled and 571 of mental disabled were analyzed. For the analysis, the structural equation model was used to verify the effect of mediation and group difference. The result of the study were as follows. First, disability acceptance of the disabled people effect on the life satisfaction by policy trust, and this was verified with partial mediated model. Second, In both groups, the external physical disabled and metal health disabled, disability acceptance and policy trust were the predictors of life satisfaction. Third, the difference in path coefficients between the two groups of external physical disabled and mental disabled was identified. Based on the results of this study, action plans were discussed to improve the life satisfaction of the disabled.

• Physical Therapy Korea
• /
• v.15 no.2
• /
• pp.11-19
• /
• 2008

Studies of attentional focus effects, have shown that the performer's attentional focus plays an important role in the performance and learning of motor tasks. We examined the influence of attentional focus on the performance of dual tasks (a postural task and a suprapostural task) and used electromyography (EMG) to examine whether the differences between external and internal focus were also manifest at the neuromuscular level. The subjects (n=40) stood on a balance board (postural task) and held a bar horizontally (suprapostural task). All of the subjects performed under different attentional focus conditions: external (balancer on balance board) or internal (feet) focus on the postural task, and external (balancer on bar) or internal (hand) focus on the suprapostural task. The mean displacement velocity of the bar and the percent reference voluntary contraction (%RVC) of the biceps brachii were reduced when the subjects adopted an external focus on the suprapostural task (p<.05). In addition, the mean displacement velocity of the balance board and %RVC of the tibialis anterior were reduced when the subjects adopted an external focus on the postural task (p<.05). When the subjects adopted an external focus on the suprapostural task, the mean displacement velocity of the balance board and %RVC of the tibialis anterior were also reduced (p<.05). When the subjects' attentional focus was on the postural task, there were no differences in the mean displacement and %RVC of the biceps brachii between attentional focuses. The performance of each task was enhanced when subjects focused on the respective task. The suprapostural task goals had a stronger influence on postural control than vice versa. These results reflect the propensity of the motor system to optimize control processes based on the environmental outcome, or movement effect, that the performer wants to achieve.