• Korean Journal of Child Studies
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• v.26 no.5
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• pp.311-330
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• 2005

The purpose of this study was to examine the paternal involvement tendency and its effect on adolescent's self-esteem for boys and girls. Subjects were 607 1st and 2nd grade middle school students in Busan. The data were analyzed by t-test, one-way Anova, Pearson's correlation, and multiple regression analysis. The results were as follows. The scores on paternal involvement were influenced by the amount of time spent with parents, 5days work a week of father, flexibility of leaving work-time of mother, regularity of holiday work of mother as well as adolescents' and fathers' sociodemographic characteristic. For boys, self-esteem was influenced by all sub-scales of paternal involvement : the leisure-life, proffering information, academic support, eveηday life, material support, discipline, and tradition-inheritance. For girls, self-esteem was influenced by leisure-life, proffering information, academic support, everyday life, and material supports.

• Korean Journal of Child Studies
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• v.29 no.5
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• pp.181-195
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• 2008

This study examined the effect of father's marital communication, self-esteem, and social support on 7 paternal involvement factors : leisure-life, proffering information, discipline, academic support, tradition-inheritance, material support, and everyday life. Instruments were the Korean Scale of Paternal Involvement (Kim, 2005), Marital Communication Scale (Olson, et al, 1987), Self-Esteem Scale (Rosenberg, 1965), and the Social-Support Scale constructed by the researcher. Subjects were 248 8th grade students and their fathers in Busan. Results showed that marital communication positively influenced degree of father's discipline and tradition-inheritance; father's self-esteem positively influenced degree of father's material support; father's social support positively influenced degree of father' leisure-life, proffering information, academic support, and everyday life of their adolescent children.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.353-358
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• 2001

The cement concrete pavements are designed twenty years of performance life in Korea. At the present time, some expressways have been elapsed seventy percent of performance life which are detecting local failures. The most repair methods using to repair failures are partial depth repair and full section repair. These methods are most important bonding strength between rapid curing materials and substrate concrete pavements. This study was performed to evaluate bonding strength of the composites section made of rapid curing material and substrate concrete pavements. The pull-out tester was used to test bonding strength for the composites section made of each materials. In the results of the test, the bonding strength values of the epoxy mortar and acrylic mortar are higher than those of the other materials. The performance life of repaired section is affected by various factor. The bonding strength of bonded composites section may be affect the performance life, significantly.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.711-714
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• 2002

Although recent research of metallic materials in high temperature fatigue have been much accomplished, many studies about brittle material as a die steel in high temperature fatigue does not have been reported. Especially, the study on the fatigue behavior over the transformation temperature is not studied sufficiently because of its difficult analysis and experiment. Therefore, reliable results of brittle material in high temperature fatigue behavior are needed. In this paper, stress-strain curves and stress-life curves in die STD61 steel at 700 and 900 are carefully examined, as the basic experimental data are used to predict from fatigue life over 700.

• Journal of Applied Reliability
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• v.11 no.4
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• pp.357-369
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• 2011

Eco-robot for collecting recycling products is the machine which collects non-industrial wastes such as cans, PET bottles and etc. to reuse them as recycling resources. This eco-robot is operated in the condition that it should compress and hold various products without knowing their geometric shapes and material properties. For this reason reliability problems like malfunction or failure. comes to emerge, but the reliability test conditions to assess its performance and durability have not been founded yet. Therefore in this research failure mechanism of the eco-robot was analyzed and life test equipment which can reproduce actual usage conditions was developed. The compression levels in the life test were determined by measuring the crushing force acting on test products and Furthermore the test specimens which have equivalent shape and material properties with those of cans and PET bottles were proposed by simulating the deformation characteristics so that the actual compression conditions were set up in the test.

• Korean Journal of Adult Nursing
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• v.18 no.2
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• pp.272-283
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• 2006

Purpose: This research was done to explore the meaning of 'well-being' as experienced by middle aged people. Method: The data were collected by individual in-depth interviews with 107 middle aged adults and it was analysed using qualitative content analysis. Results: 4 components of the meaning of well-being as perceived by the participants were identified as follows: the life of free without physical discomfort and psychosocial distress; the life of comfort with plenty of time, space, material, and mind; the life of purity with natural material and honest mind; the life of harmony with extended consciousness. Conclusion: Therefore the identified meanings of the well-being in this study should be reflected to the nursing education and the nursing practice.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.25-28
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• 2000

In this paper, the technology for accelerating degradation & life estimation on the traction motor was introduced with the stator form-winding sample coils of the 200 Class insulation system The accelerative degradation was performed in 10 cycles, which were composed of thermal stress, fast rising surge voltage, vibration, water immersion and overvoltage applying. After aging of 10 cycles, condition diagnosis test such as insulation resistance & polarization index, capacitance & dielectric loss and partial discharge properties were investigated in the temperature range of $20{\sim}160^{\circ}C$. Relationship between degradation conditions and diagnosis results were analyzed to find an dominative degradation factor at the end-life point

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.10a
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• pp.73-76
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• 2000

Traction motors that is one of the rotating machines for urban transit EMU have been subjected to increased demand for higher operating temperature, more demanding duty cycles, higher starting current, frequent voltage transients and severe environmental exposure. With the advent of PWM drives using power IGBTs in addition to the thermal considerations, it is important to take into account the impact of the dielectric stress upon the winding insulation system life. In analyzing the life of the stator winding, which is the heart of the motor, the majority of all winding failures are usually caused by a combination of various stresses acting on the insulation materials and system. In this paper, to evaluate the expected life of traction motor for urban transit E.M.U. it is proposed a new test method of complex accelerating degradation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.8 s.227
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• pp.1174-1182
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• 2004

Recently, Self Piercing Rivet(SPR) has been spotlighted in the automotive industry as a substitutive resort of spot welding and has also been watched by the designer as lightening a car body due to their superior assembly processes. Fatigue behavior of SPR joint needs to be investigated experimentally and numerically to predict its structural stiffness and fatigue life. Testing of lap-shear specimens with various material combinations is performed to obtain the joining strength and the fatigue life of SPR connections. The simulation of SPR lap-shear specimens is also conducted to obtain the structural stiffness of SPR connections under different material combinations. A Finite element model of the SPR lap-shear specimen is developed using a FEMFAT SPR pre-processor. The fatigue lift of SPR specimen is predicted using a FEMFAT 4.4e based on the liner finite element analysis.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.716-721
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• 2004

Corrosion highly affects to reduce lifetime and performance of machinery metallic components. The effects of shot peening on the fatigue life of metal material under corrosive environment are investigated in this paper. Experimental results show that the fatigue limit of shot peened specimen increases about 52$\%$. That means the fatigue life of metallic components is highly extended by shot peening. The corrosion greatly reduces the fatigue strength depending on the corrosive condition from one week up to one year. In case of shot peened specimen, the corrosion does not reduce the fatigue strength and fatigue life up to six months. It means that shot peening has superior effectiveness to reduce the influence of corrosion to the metallic materials.