• The Journal of Korean Society for School & Community Health Education
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• v.9 no.2
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• pp.1-13
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• 2008

Objectives: Literature has shown the relationship between the use of harmful media and sexual behaviors among adolescents. Laws and regulations of violent and sexual mass media are getting stricter, but young children reported that they were still accessible to these harmful materials. It might be due to the development of new techniques in media delivery and new trends of game addict among Korean adolescents. Since there were very few studies on recent harmful media available to young children, the authors explore the usability of harmful media and identify related factors that can predict adolescent sexual attitudes and activities. Methods: This study was conducted secondary analysis using the internal data that were drawn from National Youth Committee's survey of adolescent harmful environment in 2007. The self-reported questionnaires were administered to 13,721 adolescents who were randomly selected based on strata of geography, school, and gender. Results: Adolescents accessed mostly to NC-19(No Children under 19) TV programs(35.8%) and AO(Adult Only) games(35.5%). Most of them reported that they did not have difficulty in the contact of these harmful media. The factors that can predict adolescent sexual intercourse are male adolescents, attending high school, not being satisfied with family life and school, contact with phone-advertising of sex, AO games and other online games, viewing adult videos, or reading adult books. Conclusions: When sex education is designed, an instructor considers not only students' demographic characteristics but also the strategies to deter the use of harmful media especially for game materials.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.51
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• pp.11-19
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• 1999

This study intends to define $\ulcorner$personality$\lrcorner$ as $\ulcorner$Human-ware$\lrcorner$ based on $\ulcorner$Gene-ware$\lrcorner$ in business management. The sides of personality in management are important source of manifestation of ‘Synergy’, because the importance of personality, that is, $\ulcorner$attitude$\lrcorner$ in individuals is increasing compared with the traditional techniques, $\ulcorner$craft$\lrcorner$. In this work it is considered that Human-ware activates interchange in reciprocal relation between Gene-ware and Hard-ware and performs balancing, intermediating (catalyzing) functions in relative that things(Geneware $\leftrightarrow$ Humanware $\leftrightarrow$ Hardware). $\ulcorner$Gene-ware$\lrcorner$ represents factor and phenomena of life in evolutionary information as human instincts, system of Gene-duum(Gene＋Residuum(in phenomenology) ), Synchronization(in structuralism). In this view, this paper defines the concepts and effects of personality in management as the results of creative and stational functions of Human-ware. And this paper intends to identify the strata of psycho in human as three vertical aspects of $\ulcorner$Manifest$\lrcorner$, $\ulcorner$Latent$\lrcorner$, and $\ulcorner$Found$\lrcorner$, in this respects, function of Human-ware have analogy to that of Manifest in psychological behaviors. Finally, reviewing the Ford system based on Fordism and Taylor's system in Industrial Engineering, pursues the meaning and importance of personality, that is Humanware in management.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.4
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• pp.351-359
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• 2007

Multi-axial compression tests have been frequently conducted to evaluate the in situ properties of rock masses and the mechanical behaviors of rock strata through the model tests. Without the proper boundary condition for the model tests, the mechanical behavior of rock mass would deviate, as can be expected, from the in situ conditions. The boundary condition will affect the internal stress distribution of the specimens and cause some distortion on the measurement. In this study, a design process regarding the steel brush, which has been employed for multi-axial compression test to reduce the frictional restraint along the specimen/loading platen interface, is introduced. The individual brushes are regarded as a simple column and beam to calculate the cross-sectional size and length of the brushes in consideration of the buckling capacity and the allowable deflection.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.989-1002
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• 2018

Grouting for the rock joint is to strengthen the rock strata by infiltrating cement grout materials into the rock joints. Grouting is one of a field of study which is difficult to develop deterministic and quantitative design approach because of multiphase behaviors of grout materials and 3 dimensional features of rock joints. Therefore, GIN (Grouting Intensity Number) can be a good index with appropriate monitoring of pressure and volume of grout. In this paper, we investigate the effects of joint roughness (JRC) and rheology of cement material during the infiltration of cement grout material into rock joint through CFD (computational fluid dynamics) analyses. With rough joint surface and increase of WC ratio, the frictional resistance during the grouting increases. The results have been summarized with polynomial correlations.

• The Journal of Engineering Geology
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• v.12 no.4
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• pp.471-484
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• 2002

Alluviums in the Keum River watershed cover an areal extent of $3,029{\;}\textrm{km}^2$ and contain about 8.1 billion tons of groundwater. However, the waters are severely polluted by nitrate, possibly due to the application of nitrogen fertilizer (>250 N kg/ha) on agricultural land. This paper aims to elucidate the pollution status and behaviors of nitrate in alluvial groundwaters in the Keum River watershed area, based on regional hydrogeochemical study. Most of the collected samples (n = 186) are polluted by nitrate (average = 42.2 mg/L, maximum = 295 mg/L). About 29% of the samples have the nitrate concentrations exceeding Korean Drinking Water Standard (44 mg/L $NO_3$). The distribution of nitrate concentrations in the study area is largely dependant on geochemical environments of alluvial aquifers. In particular, the decrease of redox potential of alluvial groundwaters showed a good correlation with the decreases of nitrate, iron, and manganese concentrations. Thus, the change of redox state in alluvial aquifers, likely reflecting their sedimentary environments, controls both the behavior and fate of nitrogen compounds and their natural attenuation (denitrification) in aquifers. A carbon-rich, silty layer within alluvium strata forms a reducing condition and possesses a buffering capacity on nitrate pollution.

• Journal of the Korean Geotechnical Society
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• v.23 no.10
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• pp.47-56
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• 2007

In this research, the effects of the gravel content on the liquefaction behavior for both of the isotropically and $K_0-anisotropically$ consolidated gravel-sand mixtures are investigated. for this purpose, the cyclic triaxial tests for the specimens with the same relative density (Dr=40%) and variations of gravel content were performed. On the other hand, a series of undrained cyclic triaxial tests were carried out on the isotropically consolidated gravel-sand mixtures with the same void ratio (e=0.7) and from 0% to 30% gravel contents. Void ratios of gravel-sand mixtures with the same relative density (Dr=40%) are found to decrease significantly with the increase of the gravel content from 0% to about 70% and increase thereafter. But the void ratio of the sand matrix among the gravel skeleton increases with the increase of the gravel contents. Test results are as follows : for the isotropically consolidated specimen with 40% of relative density and low gavel contents (GC=0%, 20%, 40%), pore water pressure development and axial strain behavior during undrained cyclic loading show similar behavior to those of the loose sand because of high void ratio, and the specimens with high gravel content (70%) both pore pressure and strata behaviors are similar to those of dense sand. And the isotropically consolidated specimens with the same void ratio (e=0.7) and higher gravel contents show the same behavior of pore water pressure and axial strain as that of the loose sand, but for the lower gravel content this behavior shows similar behavior to that of dense sand. The liquefaction strength of the isotropically consolidated specimens with the same relative density increases with gravel content up to 70%, and the strength decreases with the increase of the gravel content at the same void ratio. Thus, it is confirmed that the liquefaction strength of the gravel-sand mixtures depends both on relative density and void ratio of the whole mixture rather than the relative density of the sand matrix filled among gravels. On the other hand, the behavior of pore water pressure and axial strain for the $K_0-anisotropically$ consolidated gravel-sand mixtures shows almost the same cyclic behavior of the sand with no stress reversal even with some stress reversal of the cyclic loading. Namely, even the stress reversal of about 10% of cyclic stress amplitude, the permanent strain with small cyclic strain increases rapidly with the number of cycles, and the initial liquefaction does not occur always with less than maximum pore water pressure ratio of 1.0. The liquefaction resistance increases with the gravel contents between 0% and 40%, but tends to decrease beyond 40% of gravel content. In conclusion, the cyclic behavior of gravel-sand mixtures depends on factors such as gravel content, void ratio, relative density and consolidation condition.