• Structural Engineering and Mechanics
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• v.5 no.2
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• pp.137-148
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• 1997

In computing eigenvalues for a large finite element system it has been observed that the eigenvalue extractors produce eigenvectors that are in some sense more accurate than their corresponding eigenvalues. From this observation the paper uses a patch type technique based on the eigenvector for one mesh quality to provide an eigenvalue error indicator. Tests show this indicator to be both accurate and reliable. This technique was first observed by Stephen and Steven for an error estimation for buckling and natural frequency of beams and two dimensional in-plane and out-of-plane structures. This paper produces and error indicator for the more difficult problem of three dimensional brick elements.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1848-1853
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• 2016

Control Rod Position Indicator in nuclear reactor vessel has developed for small reactor in Korea. Because of severe environment in reactor vessel, target of this study is to develop the suitable position indicator. In this study, solenoid type position indicator made of Mineral Insulated Cable(MI Cable) was introduced to adapt in severe environment. And inductance of the solenoid was used to indicate the rod position for high precision. But problem of this concept is that a linear slope of inductance is changed by temperature effect. To resolve this problem, two sensing coils were introduced for temperature compensation. A role of the sensing coil is to make reference linear equation about certain temperature. To confirm this concept, also, inductance of solenoid and sensing coils were measured at room and high temperature (${\sim}300^{\circ}C$). The results of measurement show that the position error of sensing coil between room and high temperature was about 2%. But it was identified that this error was resulted from insufficient test environment (temperature error between solenoid and sensing coils was about 2% at high temperature condition). Therefore, solenoid type position indicator shows that it is very suitable in reactor vessel as a high precision rod position indicator.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.6
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• pp.1025-1033
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• 2010

This paper proposes a method to improve and analysis error cause of FI(Fault Indicator) information to be used for detecting fault section in distribution automation system. FI error cause is made by consideration fault current magnitude and time. So, a new method to prevent FI error is proposed to include fault current magnitude, time and direction. Therefore, it's considered network environments that grounded and ungrounded network in distribution automation system. The proposed method is proved by Matlap Simulink. By the result in this research, it's possible to quickly restoration, supplying stability and reliability power to customer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7C
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• pp.659-664
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• 2006

We propose two error correcting algorithms for high-density optical storage systems. The first algorithm reduces the false-erasure declaration by reducing the sensitivity on random errors and increases the code rate using a simple erasure indication method. The second one exploits just the known indicator flag instead of error correcting code such as Reed-Solomon(RS) code. The proposed algorithms are superior to the error correcting algorithms of conventional systems such as DVD and BD.

• Structural Engineering and Mechanics
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• v.4 no.2
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• pp.191-202
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• 1996

This paper presents a construction of adaptive boundary element for the problem with mixed boundary conditions such as heat transfer between heated body surface and surrounding medium. The scheme is based on the sample point error analysis and on the extended error indicator, proposed earlier by the authors for the potential and elastostatic problems, and extended successfully to multidomain and thermoelastic analyses. Since the field variable is connected with its derivative on the boundary, their errors are also interconnected by the specified condition. The extended error indicator on each boundary element is modified to meet with the situation. Two numerical examples are shown to indicate the differences due to the prescribed boundary conditions.

• International Area Studies Review
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• v.12 no.3
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• pp.171-194
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• 2008

This paper analysis the long-run demand for monetary indicator M2 and Liquidity indicator L in Korea in the period from 1980:1 to 2006:3 by cointegration and error correction models. The empirical evidence that M2, L in Korea is meaningfully cointegrated with income, interest rate, exchange rate, inflation uncertainty, real effective exchange rate, exchange rate uncertainty and LIBOR, thus showing the existence of long-run demand function under open-economy framework.

• 한국전산유체공학회:학술대회논문집
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• 2004.03a
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• pp.77-82
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• 2004

A new anisotropic mesh refinement method is proposed. The new method is based on a simple second order interpolation error indicator. Therefore, it is methodologically direct and intuitive as compared with traditional anisotropic refinement strategies. Moreover, it does not depend on the mesh type. The error indicator is face-wisely calculated for all faces in a mesh and the cell refinement type is determined by the configuration of face markings with a given threshold. For the sake of simplicity, an application for a poisson equation on a triangle mesh is considered. The error field and resultant mesh refinement pattern are compared and effects of the threshold selection are discussed. Applying anisotropic refinement with various thresholds, we observed higher convergence rates than those in the uniform refinement cases.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.7
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• pp.629-634
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• 2008

This paper presents the flight test procedure and the results for the airspeed indicator calibration of a light airplane the name of ChangGong-91, which is the first type certified aircraft from Korean Ministry of Construction and Transportation, as a part of the flight test validation to get the certification. The flight tests for airspeed position error calibrations are conducted using tower fly by method in order to calibrate swivel head testboom which is attached to the right wing tip of the airplane. Also system to system method is applied in order to calibrate the airspeed indicator of the cockpit. The flight test is conducted at the basis of the 'Korean Airworthiness Standard' which is the regulation of Korean Ministry of Construction and Transportation. The airspeed error range for the testboom and the airspeed indicator are determined to $-0.75{\sim}+0.75$ knot and to $-4.0{\sim}+2.0$ knots, respectively. The calibration results are applied to ChangGong-91 Flight Operation Manual.

• Food Science of Animal Resources
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• v.33 no.1
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• pp.31-38
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• 2013

If the time-temperature indicator (TTI) experienced a different temperature than the accompanied packaged food, influenced by heat transfer between the TTI, package, and ambient air, TTI would incorrectly predict the food quality changes with temperature. Temperature distributions of a finite slab with different sizes, representing beef packaged with TTI, were estimated by the finite element method (FEM). The thermal properties of the beef and TTI, such as heat capacity, density, and heat conductivity, were estimated from the relevant equations using their chemical compositions. The FEM simulations were performed for three cases: different locations of TTIs on the beef, different thicknesses of beef, and non-isothermal conditions of ambient air. The TTIs were mounted in four different locations on the beef. There was little difference in temperature between four locations of the TTI on the package surface. As the thickness of the slab increased, the temperature of the TTI changed faster, followed by the corner surface, as well as middle and bottom parts, indicating the possible error for temperature agreement between the TTI and the slab. Consequently, it was found that any place on the package could be selected for TTI attachment, but the package size should carefully be determined within a tolerable error of temperature.

• Journal of Mechanical Science and Technology
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• v.20 no.12
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• pp.2189-2196
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• 2006

The present work is concerned with the development of a procedure for adaptive computations of shear localization problems. The maximum jump of equivalent strain rates across element boundaries is proposed as a simple error indicator based on interpolation errors, and successfully implemented in the adaptive mesh refinement scheme. The time step is controlled by using a parameter related to the Lipschitz constant, and state variables in target elements for refinements are transferred by $L_2$-projection. Consistent tangent moduli with a proper updating scheme for state variables are used to improve the numerical stability in the formation of shear bands. It is observed that the present adaptive mesh refinement procedure shows an excellent performance in the simulation of shear localization problems.