• International journal of advanced smart convergence
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• v.3 no.1
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• pp.7-10
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• 2014

Upbringing requires an active intervention in the process of children growing up. Convergence in technology and media makes it possible to augment nurturing by making blended infrastructures with new digital resources available in learning environments at schools. A game-based provision of educationally-valuable content within a collective, virtual environment combined with an analysis of events in the game after it has been played (blended nurture environment) may help to better communicate human values especially where old-fashioned discussion methods fail or do not fulfill the promise of effective, educational institution-based methods of bringing up. This is where life sciences, psychology, media, pedagogy and technology (need to) converge.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.129-135
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• 2004

This study was to evaluate the effect of carbon content on metallic change and fatigue characteristics with Fe-29% Ni-17% Co, low heat expansion alloy, widely using electronic components, precision machines, and sealing with glass and metal etc. The steels were fabricated with variation of carbon content, 0, 0.03, 0.06, 0.1, and 0.20% with VIM and tensile test and fatigue test were performed to achieve the above purpose. The more carbon content, the higher hardness value and yield strength. But elongation of 0.03%C, 0.06%C, and 0.10%C specimen decreased about 2.2%, 1.5% and 0.8% respectively mote than that of the base metal. Especially the strength and elongation of 0.20%C specimen increased simultaneously about 14.4% and 7.5%. Fatigue life of 0.03%C specimen decreased but the more carbon content, the higher fatigue life over 0.06% carbon content more than that of base metal.

• Communications for Statistical Applications and Methods
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• v.26 no.6
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• pp.557-573
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• 2019

Mortality study is an essential component of actuarial risk management for life insurance policies, annuities, and pension plans. Life expectancy has drastically increased over the last several decades; consequently, longevity risk associated with annuity products and pension systems has emerged as a crucial issue. Among the various aspects of mortality study, a consideration of the cause-of-death mortality can provide a more comprehensive understanding of the nature of mortality/longevity risk. In this case study, the cause-of-mortality data in Korea and the US were analyzed along with a multinomial logistic regression model that was constructed to quantify the impact of mortality reduction in a specific cause on actuarial values. The results of analyses imply that mortality improvement due to a specific cause should be carefully monitored and reflected in mortality/longevity risk management. It was also confirmed that multinomial logistic regression model is a useful tool for analyzing cause-of-death mortality for actuarial applications.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.122-129
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• 2004

In plastic working, as working becomes speedy, automatic and working condition deteriorates, the increase of forging working has been remarkable. Therefore, we need the estimation of mold lift in detail, in order to counterplan of effective mold life extension. In this study, on the SKH51, mold steel which is forged by cold working and the KCW1, tool steel of low alloy, we estimated mold life on the base of FEM analysis and investigated mold lift by low cycle fatigue test. Also, this paper suggested a new method of estimation of mold lift.

• Journal of the Korean Data and Information Science Society
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• v.14 no.3
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• pp.511-523
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• 2003

Internet has become an important part of teenagers' life and has changed the life style of teenagers. Internet can be an useful tool for educating teenagers and also can be misused as a cyberspace for social problems. Recognizing that teenagers spend most of their free time enjoying internet and they form their own new life culture, it is needed to develop practical strategies for maximizing the positive effect of internet on the teenagers' culture. The purpose of this research is to suggest a desirable way for forming teenagers' healthy internet-based culture. The research was conducted by the survey of teenagers in the city of Pyongtaek on their use of internet and their problems The survey shows that most of teenagers are using internet in order to release the stress and most of them are hooked on it. It also indicates that cyber police and volunteer groups should be formed to help the desirable teenagers' internet-based culture.

• ALGAE
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• v.17 no.3
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• pp.153-159
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• 2002

Partial 16S rRNA gene sequences of seven cyanophycean strains from the National Instiute of Environmental Research of Korea - Microcystis aeruginosa, M. aeruginosa f. aeruginosa, M. ichthyoblade, M. viridis, Anabaena flos-aquae, and Oscillatoria sancta - were analyzed and the phylogenetic relationship of Microcystis among Cyanophyceae were evaluated. Based on sequence analysis results, Microcystis is monophyletic, the clade of which supported 100% bootstrap tress, and distinguished clearly from the other taxa. Therefore, the partial 16S rRNA gene sequences can be a useful and efficient tool for distinguishing Microcystis from other cyanophycean without axenic culture or cloning.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.1
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• pp.58-65
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• 2005

A planetary gear trains has characteristics in compactness, power transformation ability and constant meshing. Usability is increased in applications of auto transmission and industrial gearbox. Study on optimum design of planetary gear train has been progressed on miniaturization of weight, miniaturization of planetary gear train and improvement of high strength. There are demands of study f3r the planetary gear train required long life estimation. In this work being considered life, strength, interference, contact ratio and aspect ratio, the optimum design algorithm is proposed to reduce the volume of planetary gear train with transferring the same amount of power. In the design of algerian for planetary gear train, the determination of teeth number is separated to achieve simplicity and the simulated annealing method as a global optimal technique is used far optimal design method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.352-361
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• 2003

A fatigue damage accumulation model based on the continuum damage mechanics theory was develope(1 where modules decay ratios in tension and shear on used as indicators for damage variables D . In the model, the damage variables are considered to be second-order tensors. Then the maximum principal damage variable, $D^*$ is introduced According to the similarity to the Principal stress, $D^*$ is obtained as the maximum eigen value of damage tensor [D']. Under proportional tension and torsion loadings, fatigue lives were satisfactorily predicted at any combined stress ratios using the present model in which the fatigue characteristics only under uniaxial tension and pure torsion loadings on needed. Fatigue life prediction under uniaxial tension and pure torsion loadings, was performed based on the damage mechanics using boundary element method.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.6
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• pp.64-73
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• 2004

A fatigue damage accumulation model based on the continuum damage mechanics theory was developed where modulus decay ratios in tension and shear were used as indicators for damage variables D. In the model, the damage variables are considered to be second-order tensors. Then, the maximum principal damage variable, $D^*$ is introduced. According to the similarity to the principal stress, $D^*$ is obtained as the maximum eigen value of damage tensor [D]. Under proportional tension and torsion loadings, fatigue lives were satisfactorily predicted at any combined stress ratios using the present model in which the Fatigue characteristics only under uniaxial tension and pure torsion loadings were needed. Fatigue life prediction under uniaxial tension and pure torsion loadings, was performed based on the damage mechanics using boundary element method.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.62-68
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• 2009

Life Cycle Cost(LCC) is adopted to decide the target of safety level in designing suspension bridges. The LCC are evaluated considering two types of uncertainty; aleatory and epistemic. The nine alternative designs of suspension bridge are simulated to decide the safety level which can minimize the LCC. The LCC is calculated through the probability of failure and safety index including the uncertainty. This method results in the useful tool deciding the optimum safety level with minimal LCC as the main design factor.