• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.9
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• pp.781-785
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• 2000

Chalcogenide glasses are suggested as a candidate for optical recording. In this study, we have investigated the holography recording and reconstruction of the polarization state in chalcogenide As$_{40}$ Ge$_{10}$Se$_{15}$ S$_{35}$ thin films. We have used a He-Ne laser light(633nm) to probe and record of the grating. Also the polarization state of object beam was modulated with a λ/4 wave plate. The polarization state of the +1st order diffracted beam was generated by readout of the grating with a linearly polarized reference beam. It was the same-handed polarization state as the polarization state of the recording beam. The result is shown that the diffraction efficiency of circularly polarized recording represents higher than other polarization state.ate.e.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.1
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• pp.98-111
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• 1995

The objective of this work is to investigate the form of equations of state for specific refrigerants. In particular, equations of the extended van der Waals form have been studied. As a result, a new equation of state has been developed and tested over ranges of pressure and density up to 5 and 1.5 times critical, respectively. The equation of state separates the compressibility factor into two parts. One is the repulsive compressibility factor and the other is attractive. The former is in the same form of Carnahan-Starling's repulsive term with constant hard-sphere volume. The latter is based on a combination of two different functions linear to density. The equation of state developed here has 12 adjustable parameters and correlates PVT data successfully. All properties are in reduced forms.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.33-38
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• 2022

The main purpose of the study is to determine the key aspects of the mechanisms of state management of the exchange of information about cyberattacks, cyber incidents, and information security incidents. The methodology includes a set of theoretical methods. Modern government, on the one hand, must take into account the emergence of such a new weapon as cyber, which can break various information systems, can be used in hybrid wars, influence political events, pose a threat to the national security of any state. As a result of the study, key elements of the mechanisms of state management of the exchange of information about cyberattacks, cyber incidents, and information security incidents were identified.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1108-1111
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• 2003

We consider geometrical conditions of liquid crystals of bent-shape molecules that result in optically isotropic antiferroelectric structure that can be reversibly switched to birefringent states. An example of an ester based banana-shape substance is discussed that almost fulfills the ideal conditions and provides fast electro-optical switching with or without crossed polarizers.

• Journal of Korean Academy of Nursing
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• v.32 no.6
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• pp.888-896
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• 2002

The purpose of this study wsa to necessitate auricular acupressure therapy as an independent nursing intervention on cancer paitents by confirming its effectiveness. Method: The experimental study was unequivalently controlled pre-post measure study. The subjects were 40 cancer patients who were hospitalized in K medical center in Seoul. The experimental group (20) and the control group (20) were randomly assigned. As measured tools, Spielberger's State-trait Anxiety (1976) measured tool by Kim's transplation (1978). The auricular acupressure therapy was applied to experimental group, and the pre-post measure was performed to both group. The data was analyzed by using SPSS computer program that included descriptive statistics, 2-test, and t-test. Result: 1) The experimental group with the auricular acupressure therapy showed lower trait anxiety scores in comparison with the control group (t= 8.036, p=.000). 2) The experimental group which applied the auricular acupressure therapy showed lower state anxiety scores in comparison with the control group (t= 19.616, p=.000). This result showed that cancer patients with the auricular acupressure therapy applied cancer patients decreased state anxiety and trait anxiety. Therefore , effectiveness of the auricular acupressure therapy was confirmed through this study. Conclusion: According to the result, anxiety of cancer pateint should be decreased and controlled by the auricular acupressure therapy as independent nursung intervension. In addition, the auricular acupressure therapy will provide effective independent nursing intervention that will decrease anxiety on patient with other disease and will improve quality of their lives.

• Wind and Structures
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• v.31 no.5
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• pp.473-482
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• 2020

The first-order method for estimating the extreme wind pressure on building envelopes with consideration of the directionality of wind speed and wind pressure is improved to enhance its computational efficiency. In this improved method, the result is obtained directly from the empirical distribution of a random selection of annual maximum wind pressure samples generated by a Monte Carlo method, rather than from the previously utilized extreme wind pressure probability distribution. A discussion of the relationship between the first- and full-order methods indicates that when extreme wind pressures in a non-typhoon climate with a high return period are estimated with consideration of directionality, using the relatively simple first-order method instead of the computationally intensive full-order method is reasonable. The validation of this reasonableness is equivalent to validating two assumptions to improve its computational efficiency: 1) The result obtained by the full-order method is conservative when the extreme wind pressure events among different sectors are independent. 2) The result obtained by the first-order method for a high return period is not significantly affected when the extreme wind speeds among the different sectors are assumed to be independent. These two assumptions are validated by examples in different regions and theoretical derivation.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1109-1114
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• 2001

This paper describes an attempt to develop a new truss model for reinforced concrete beams failing in shear based on a rational behavioral model. The key idea incorporated with truss model is the internal force state factor which is able to express global state of internal force flow in cracked reinforced concrete beams subjected to shear and bending. A new truss model using internal force state factor may provide a comprehensive result of shear strength in reinforced concrete beams without web reinforcement.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.129.6-129
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• 2001

In this paper, we consider a class of time-varying systems with time-varying state delay. Generally, this system is affected by many uncertainties and we assume that the information of the upper bound(time-delay, uncertainty) is known. In this work, we propose a robust control for system with state delay. The stability based on Lyapunov function is presented. Finally, a numberical example is given to demonstrate the validity of the result.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.48.3-48
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• 2002

1) Linear state feedback control design problem for plant with unknown deterministic disturbance is considered and a method to realize state feedback by using adaptive observer which estimates the unknown disturbance simultaneously is proposed. 2) From the viewpoint of practical application, we propose an extended adaptive observer with direct plant path from input to output, which is necessary to use the acceleration type sensors as plant output. 3) Theoretical result is confirmed by numerical simulation of 1-DOF vibration control system.

• Journal of the Chungcheong Mathematical Society
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• v.22 no.3
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• pp.557-569
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• 2009

We present a new regularity criterion for suitable weak solutions of the steady-state Navier-Stokes equations near boundary in dimension five. We show that suitable weak solutions are regular up to the boundary if the scaled $L^{\frac{5}{2}}$-norm of the solution is small near the boundary. Our result is also valid in the interior.