• Journal of the Chungcheong Mathematical Society
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• v.17 no.2
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• pp.125-136
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• 2004

This paper introduces the notion of semi-compatible self-maps in 2-metric spaces and establishes a fixed point theorem for four self-maps, satisfying an implicit relation through semi-compatibility of a pair of self-maps. This results in another fixed point theorem for four expansion maps which generalizes and improves many results of Kang et. al. [5] with an application.

• Journal of the Korea Convergence Society
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• v.10 no.6
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• pp.269-279
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• 2019

The purpose of this study was to investigate if a positive psychological-based music therapy program for gambling addicts' families, causes explicit or implicit attitude change towards gambling addicts. The study focused on families with gambling addicts, who use counseling centers for gambling addiction, or participate in GAM-ANON (GA). The experimental group (n=11) participated in 8 sessions of a positive psychology-based group music therapy program, and the control group (n=8) participated in 8 sessions of personal counseling, or GA family gatherings. To confirm treatment effectiveness, the attitude towards the family relationship, was measured by the explicit (Family Relation Scale) and Implicit Association Task (IAT) methods. Additionally, change in emotions including and anger (PANAS, HBDIS), was measured. Results of the study showed that positive emotions increased significantly, in the positive psychotherapy-based music therapy group compared, to the control group. However, in the treatment group with implicit attitudes, the rate of association of negative words with families accelerated significantly, suggesting that gambling addicts' families may have higher negative emotions. For the future, we discussed the necessity of providing a treatment program, that can directly lead to changes in attitudes of family members of gambling addicts.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.6
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• pp.18-25
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• 2007

In a plastic metal forming of thermally rate-sensitive material, the localized shear band stems from evolution of a narrow region in which intensive plastic flow occurs. And it give rise to fatal fracture with plastic instability. The objectives of this study are to investigate the localization behavior by using numerical method and predict the failure for WHA(Tungsten Heavy Alloy). In this work, the implicit finite difference scheme is used because of the advantage about convergence and the numerical stability. This study is based on an analysed material with hardening as well as thermally softening behavior which includes isotropic strain hardening and observed the extension of localization within shear band according to material properties.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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• pp.225-231
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• 2012

Drop simulations of the board level in the flip chips with solder joints have been highlighted for years, recently. Also, through the study on the life prediction of thermal fatigue in the flip chips considering underfill, its importance has been issued greatly. In this paper, dynamic analysis using the implicit method in the Finite Element Analysis (FEA) is carried out to assess the factors effecting on flip chips considering underfill. The design parameters are size and thickness of chip, and size, pitch and array of solder ball with composition of Sn1.0Ag0.5Cu. The board systems by JEDEC standard is modeled with various design parameter combinations, and through these simulations, maximum yield stress and strain at each chip are shown at the solder balls. Modal analysis is simulated to find out the relation between drop impact and vibration of the board system.

• Transactions of Materials Processing
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• v.9 no.4
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• pp.395-403
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• 2000

Formation of Shear Band under the adiabatic condition is widely observed In the engineering materials during rapidly forming process lot a thermally rate-dependent material. The shear band stems from evolution of a narrow region in which an intensive plastic flow occurs. The shear band often plays a role of a precursor of the ductile fracture during a forming process. The objective of this study is to investigate the localization behavior using numerical method. In this work, the implicit finite difference scheme is employed due to the ease of convergence and the numerical stability It is noted that physical and mechanical properties of materials determine how the shear band is formed and then localized. Material properties can be characterized with inertia number dissipation number and diffusion number. It is observed that the dimensionless numbers effect on localization. Using a parametric study, comparison was made between CRS-1018 steel with WHA (tungsten heavy alloy). The deformation behavior of material in this study include an isotropic hardening as well as thermal softening. Moreover, this study suggests that a kinematic hardening constitutive relation be required to predict a more accurate strain level at a shear band.

• Journal of the Korean Institute of Gas
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• v.3 no.1
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• pp.64-74
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• 1999

Using the steady state gains, an appropriate criterion used for the interaction analysis among variables and the loop pairing is suggested. Based upon the suggested criterion derived from the derivative relation of implicit function, the SISO pairing which has minimum interaction among control system variables and good control performance can be determined. The relative effect among diagonal gains and off-diagona gains, which was not considered in other criteria, can be explained deterministically Also, the criterion can be easily applied to partial MIMO pairing. This criterion was applied to several examples to illustrate its usefulness in finding the feasible SISO pairing and MIMO pairing

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.277-282
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• 2009

A temperature equation which is derived from an enthalpy transport equation by using an assumption of a constant specific heat is very attractive for analyses of heat and fluid flows. It can be used for an analysis of a solid-fluid conjugate heat transfer, and it does not need a numerical method to find temperature from a temperature-enthalpy relation. But its application is limited because of the assumption. A new method is derived in this study, which is a temperature-explicit formulation of the energy equation. The enthalpy form of the energy equation is used in the method. But the final discrete form of the equation is expressed with temperature. It can be used for a solid-fluid conjugate heat transfer and multiphase flows. It is found by numerical tests that it is very efficient and as accurate as the standard enthalpy formulation.

• Journal of computational fluids engineering
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• v.10 no.1
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• pp.16-23
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• 2005

The objective of this research is to estimate two dimensional ablating and charring of heat shield materials in severe aero-thermal heat transfer. This estimation requires an accurate and rapid technique for its serious heat transfer with a moving boundary. Aerodynamic heating is obtained by an explicit relation which is a function of Mach number and air condition, while a fully implicit method is used for heat transfer calculations. Moving boundary is captured by FLIAR method which is a subgroup of VOF. Thickness of ablating and charring of heat shield, temperature of the moving surface and rate of radiation heat are calculated and compared with references. The results are in good agreement with other calculations.

• Korean Journal of Cognitive Science
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• v.7 no.3
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• pp.61-80
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• 1996

Recent studies on emotion as memory,and effects of emotion on memory were reviewied. The main issues discussed were : memory of emotional events,relation between implicit memory and emotion, and the effect of emotion on autobigraphical memory. The theoretical possibility and implications that emotion is not stored as some lower level node information in semantic network but as some higher level and inclusive information were descussed.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.278-285
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• 2011

In the present study, the numerical prediction of the oil amount leaked from the hole of a damaged tank is investigated using the improved MPS (Moving Particle Semi-implicit) method, which was originally proposed by Koshizuka and Oka (1996) for incompressible flow. The governing equations, which consist of the continuity and Navier-Stokes equations, are solved by Lagrangian moving particles, and all terms expressed by differential operators should be replaced by the particle interaction models based on a Kernel function. The simulation results are validated though the comparison with the analytic solution based on Torricelli's equilibrium relation. Furthermore, a series of numerical simulations under the various conditions are performed in order to estimate more accurately the initial amount of leaked oil.