• Nuclear Engineering and Technology
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• v.26 no.1
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• pp.19-31
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• 1994

The objective of this study is to conduct a thermal-hydraulic analysis on the spent fuel pool and to evaluate a parametric effect for the thermal-hydraulic analysis of spent fuel pool. The selected parameters are the Reynolds Number and the gap flow through the oater gap between fuel cell and fuel bundle. The simplified flow network for a path of fuel cells is used to analyze the natural circulation phenomenon. In the flow network analysis, the pressure drop for each assembly from the entrance of the fuel rack to the exit of the fuel assembly is balanced by the driving head due to the density difference between the pool fluid and the average fluid in each spent fuel assembly. The governing equations ore developed using this relation. But, since the parameters(flow rate, pressure loss coefficient, decay heat, density)are coupled each other, iteration method is used to obtain the solution. For the analysis of the YGN 3&4 spent fuel rack, 12 channels are considered and the inputs such as decay heat and pressure loss coefficient are determined conservatively. The results show the thermal-hydraulic characteristics(void fraction, density, boiling height)of the YGN 3&4 spent fuel rack. There occurs small amount of boiling in the cells. Fuel cladding temperature is lower than 343.3$^{\circ}C$. The evaluation of parametric effect indicates that flow resistances by geometric effect are very sensitive to Reynolds number in the transition region and the gap flow is negligible because of the larger flow resistance in the gap flow path than in the fuel bundle.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.1
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• pp.1-13
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• 2006

A field survey on the spatio-temporal distribution characteristics and origins of organic matter in surface sediments was carried out monthly at six stations in Gamak Bay, South Korea from April 2000 to March 2002. The range of ignition loss(IL) was $4.6{\sim}11.6%(7.1{\pm}1.6%)$, while chemical oxygen demand(CODs) ranged from $12.25{\sim}99.26mgO_2/g-dry(30.98{\pm}19.09mgO_2/g-dry)$, acid volatile sulfide(AVS) went from no detection(ND)${\sim}10.29mgS/g-dry(1.02{\pm}0.58mgS/g-dry)$, and phaeopigment was $6.84{\sim}116.18{\mu}g/g-dry(23.72{\pm}21.16{\mu}g/g-dry)$. The ranges of particulate organic carbon(POC) and particulate organic nitrogen(PON) were $5.45{\sim}23.24 mgC/g-dty(10.34{\pm}4.40C\;mgC/g-dry)$ and $0.71{\sim}2.99mgN/g-dry(1.37{\pm}0.58mgN/g-dry)$, respectively. Water content was in the range of $43.1{\sim}77.6%(55.8{\pm}5.6%)$, and mud content(silt+clay) was higher than 95% at all stations. The spatial distribution of organic matter in surface sediments was greatly divided between the northwestern, central and eastern areas, southern entrance area from the distribution characteristic of their organic matters. The concentrations of almost all items were greater at the northwestern and southern entrance area than at the other areas in Gamak Bay. In particular, sedimentary pollution was very serious at the northwestern area, because the area had an excessive supply of organic matter due to aquaculture activity and the inflow of sewage from the land. These materials stayed longer because of the topographical characteristics of such as basin and the anoxic conditions in the bottom seawater environment caused by thermocline in the summer. The tendency of temporal change was most prominently in the period of high-water temperatures than low-water ones at the northwestern and southern entrance areas. On the other hand, the central and eastern areas did not show a regular trend for changing the concentrations of each item but mainly showed a higher tendency during the low-water temperatures. This was observed for all but AVS concentrations which were higher during the period of high-water temperature at all stations. Especially, the central and eastern areas showed a large temporal increase of AVS concentration during those periods of high-water temperature where the concentration of CODs was in excess of $20mgO_2/g-dry$. The results show that the organic matters in surface sediments in Gamak Bay actually originated from autochthonous organic matters with eight or less in average C/N ratio including the organic matters generated by the use of ocean, rather than terrigenous organic matters. However, the formation of autochthonous organic matter was mainly derived from detritus than living phytoplankton, indicated the results of the POC/phaeopigment ratio. In addition, the CODs/IL ratio results demonstrate that the detritus was the product of artificial activities such as dregs feeding and fecal pellets of farm organisms caused by aquaculture activities rather than the dynamic of natural ocean activities.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.319-332
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• 2015

The pressure wave formed by the piston effects of the train proceeds within the tunnel when a train enters the tunnel with a high speed. Depending on the condition of tunnel exit, the compression waves reflect at a open end, change to the expansion waves, transfer to tunnel entrance back. Due to interference in the pressure waves and running train, passengers experience severe pressure fluctuations. And these pressure waves result in energy loss, noise, vibration, as well as in the passengers' ears. In this study, we performed comparison between numerical analysis and field experiments about the characteristics of the pressure waves transport in tunnel that appears when the train enter a tunnel and the variation of pressure penetrating into the train staterooms according to blockage ratio of train. In addition, a comparative study was carried out with the ThermoTun program to examine the applicability of the compressible 1-D model(based on the Method of Characteristics). Furthermore examination for the adequacy of the governing equations analysis based on compressible 1-D numerical model by Baron was examined.

• Sim-seong Yeon-gu
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• v.26 no.2
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• pp.149-188
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• 2011

This thesis presents the research of analytical psycholoy in respect of Jindo Dasiraegi. In a funeral of Jindo, situated in the southern island of Korea, there is a theatrical performance which is called Dasiraegi(rebirth). This research manifested a basic, universal meaning of psychological approach related the implicit of death in performing theatre from a analytic psychological point of view. The characteristics of this theatrical feast are like these ; 1) funeral festival 2) entrance of clown(the existence of antipole and conflict) 3) eroticism 4) active participation of female character 5) difficulty in her delivery 6) the moment of joy thanks to childbirth. The prerequisite of this feast should be a propitious mourning of person dying old and rich. That is, after having a complete life, it could be an entire death. Three main roles in Dasiraegi ; a bat-blind buddhist devotee, a strolling actor teasing men, an apostate monk, theses characters lock horns in a form of triangle conflict relations, then they keep a balance with a fake mourner as a protagonist , modulator and narrator. These characters are indeed clowns who manifested a metaphor as a decent, sacred and reasonable part of shadow regards group consciousness. The alive and the deceased, mourner and fake mourner, piety and confusion, wail and laugh, silence and grumble, death and birth, diverse antipole all coexist then theses are in harmony. The blind devotee and the monk are in antipole, the entertainer(anima) provokes a conflict between them. The infant is a solution as same as a result of conflict. This conflict seems to be eased by birth of a baby which is a symbol of wholeness(ganzheits) but the conflict of antipole is reenacted as insisting his parental right so this solution is leaving the baby to the chief mourner who is fourth character and the first beginning. Unconsciousness, hereby, is negotiating with appeared reality. The Images in unconsciousness are conscious and this new energy in unconsciousness is proceeding towards consciousness, then it became a therapeutic power for the loss of consciousness. Dasiraegi is the play of consolation much more for the alive than the deceased. The death signified not a loss but a resurrection and this intends a transition of new leading independent role for the alive. These make us have more prudent consideration concern the double sense of renewal for the dead and the alive. It is preserved as only a form of drama on stage after disappearance of Dasiraegi in a funeral recently. Dasiraegi was a manifestation of unconsciousness for compensation about the unilateral attitude of group consciousness to the strict death excessively. Therefore, this will enable reflect the relativeness and the attitude which regards the death as the end today.