• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2765-2770
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• 2008

The purpose of tunnel ventilation system for long road tunnels is to keep certain levels of Visibility Index and the concentration of CO. Additional equipments such as jet fans are used in road tunnel to discharge pollutants in the road tunnel. The control algorism of tunnel ventilation system takes the value of sensors as input, and then gives the operation method of jet fans in tunnel as output. Information on the variation of CO concentration in tunnel when jet fans are running is needed to minimize their operation time. Numerical analysis is used in this paper because of the difficulty of conducting experiments under standard condition for ventilation of road tunnel. The concentration of CO has been calculated by using 3-dimensional CFD under transient condition with speed of cars, quantity of air ventilation, and the results for various operation position of jet fans are compared.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.10-13
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• 2010

The flow field in road tunnel is influenced by some facts such as piston effect of vehicle's move, operation of ventilation facilities, natural wind and buoyancy effect of fire plume. Among those, jet fan is one of main ventilation facilities especially in longitudinal ventilation system of tunnel. In this study to analyze tunnel flow induced by operation of jet fan, numerical simulation has been carried out. The velocity distributions and streamlines in tunnel are examined to consider the three-dimensional characteristics of tunnel flow caused by jet fan.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2008.10a
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• pp.33-41
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• 2008

The longest tunnel has been halted at Daekwanryung by the failure of the host country of the Winter Olympiad in 2014, but modern High-Power TBM will come to Korea to excavate these long tunnels to establish the better horizontal connection between the western and eastern countries to improve the strong powerful logistic strategy of Korean peninsula. Train operation provides a key function of air movements in a long underground tunnel, and heat generation from transit vehicles may account of the most heat release to the ventilation and emergency systems. This paper indicates the optimal fire suppress services and safety provision for the long railway tunnel which is designed twin tunnel with length 22km in Gangwon province of Korea. The design of the fire-fighting systems and emergency were prepared by the operation of the famous long-railway tunnels as well as the severe lessons from the real fires in domestic and overseas experiences. Designers should concentrate the optimal solution for passenger's safety at the emergency state when tunnel fires, train crush accidents, derailment, and etc. The optimal fire-extinguishing facilities for long railway tunnels are presented for better safety of the comfortable operation in this hard rock tunnel of eastern mountains side of Korea. Since year 1900, hard rock tunnel construction has been launched for railway tunnels in Korea, tunnels have been built for various purposes not only for infrastructure tunnels including roadway, railway, subway, and but also for water and power supply, for deposit food, waste, and oils etc. Most favorable railway tunnel system was discussed in details; twin tunnels, distance of cross passage, ventilation systems, for the comfortable train operations in the future.

• Explosives and Blasting
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• v.33 no.3
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• pp.14-20
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• 2015

Tunnel blasting that plays the most important role in the construction of a drill & blast tunnel, shows a big difference in operation time according to various factors such as rock mass quality, tunnel dimension, machine performance, and the skill level of tunnel crews. This paper analyzes the differences between the time calculated by the standard of estimate and actual operation time based upon field investigations on blasting operation time in three tunnels of Korea. The result shows that actual blasting time is generally about 8%~16% less than the standard of estimate in cases that normal operations are performed. If the time delayed by unforeseen situations is included, however, it is presumed that the number of cases that actual operation time exceeds the standard of estimate are considerable. This study aims to help make a judgement over the appropriacy of the standard of estimate through continuous investigations on actual operation time, as well as improve the productivity of tunnel excavation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.04a
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• pp.114-121
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• 1995

Problems of noise and vibration induced by subway operation became one of the major factor when new subway 1 me is under consideration. One of the most economic method in reducing the noise and vibration is the increasement of the tunnel mass. . Vibration of the massive tunnel structure has been measured induced by subway operation. STEDEF system which was adopted by Seoul Metropolitan Subway Bureau has been proved that more than 99% of the vibration has been decreased at the bottom of the railway track. Most of the vibration measured inside and outside of the tunnel showed that their peak frequency is around SOHz or 100Hz. The propagation characteristics of vibration in massive tunnel , wave propagate in three directions. Overall frequency in the range of 0 to 125H2 horizontal transmission usually increase, while vertical transmission decreases about 50% in the range of 0 to 25Hz and 90Hz to 125Hz regardless of modal shape.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.207-212
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• 2005

In designing a ventilation system of a road tunnel, a possibility of using the system as a smoke control system in case of a tunnel fire has to be considered. In the present study, a numerical simulation on ventilation system is performed considering jet fan operations and moving traffic. A fire-mode operation by reversing some fan operations in case of a tunnel fire is also simulated. The results show that ventilation operation can control the pollutants effectively, and fire-mode operation can control smoke and temperature effectively to prevent a disaster.

• 한국기계연구소 소보
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• s.10
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• pp.79-97
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• 1983

This report includes the general descriptions on the Cavitation Tunnel, newly installed at the Ship Research Station, KIMM, and also on the functions and operating procedures of the major measuring equipments. It also includes the results of the trial operation of the Tunnel and testing techniques in the Cavitation Tunnel.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.575-578
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• 2006

In designing smoke-control system of rescue station in train tunnel, a purpose is to prevent a disaster by proposing the jet fan operation together with smoke-control curtain in tunnel fire. This study has investigated the relationship of the Heat Release Rate(HRR) and a adequate ventilation velocity to control the fire propagation in tunnel fire, and has improved the effect of the smoke-control curtain on preventing the flow of pollutants. In this study, Computational Fluid Dynamics(CFD) simulations with ST AR-CD(ver 3.24) were carried out on predicting the fire spreading and the flow of pollutants, considering jet fan operations and effect of smoke-control curtain. Our simulation domain is the full scale model of the 'DAEGWALLYEONG' 1st tunnel. The results represent that ventilation operation can control the fire spreading and pollutants effectively to prevent a disaster.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.628-635
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• 2000

The catenary system supported by the tunnel bracket which has been used uniquely in KNR was selected as the catenary inside narrow existing tunnel in the electrification of Kyeung-Bu Line for operation of Korea High Speed Train(KTX). It was demanded to judge the maximal operable speed of KTX in this catenary system to implement the planning. To do this, the tunnel bracket was firstly tested to obtain the characteristic data. The stiffness of this bracket are computed depending on the location which catenary installed on. Moreover, the catenary using tunnel bracket is modelled numerically respecting the bracket stiffness. Based on these, the dynamics between this catenary and KTX pantograph are simulated with the program developed by ourselves independently. The simulation result are evaluated according to the generally acceptable criteria. Consequently, the maximal operable speed of KTX in the catenary using KNR(Korean National Railroad) tunnel bracket is predicted and some items which are needed to be kept in the processing of implementation are drawn.

• Journal of Chest Surgery
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• v.26 no.5
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• pp.422-426
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• 1993

We report three cases of children who underwent definitive conversion to the Fontan circulation using a new surgical technique, Extracardiac Epicardial Lateral Tunnel. This new procedure allows the operation to be performed as a totally extracardiac operation [especially in ventricular dysfunction] and allows it to be performed in a very small atrium and in cases with unsuitable pulmonary venous drainage.Our data suggest that this procedure may achieve satisfactory hemodynamics of the total cavopulmonary connection.