• Fire Science and Engineering
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• v.25 no.5
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• pp.14-20
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• 2011

As the height of the building increases, the stack effect in stairwell that is main facilities for evacuation becomes stronger. While the pressure rise in stairwell causes difficulties on opening the door for evacuation and has effect on smoke control system, reduction of stack effect will be necessary for providing more safe evacuation environment. The field experiments on pressure field in high-rise building are carried out to present reduction method of stack effect and the numerical analyses using network model are proceeded to design quantitatively the reduction method. As the air flow supplied from outside in lower stair and exhausted to outside in upper stair is formed in stairwell, the stack effect in stairwell is expected to be decreased.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.284-288
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• 2010

Length of staircase get longer and evacuation load get heavier in proportion to the building height. Therefore evacuation time could be considered proportional to square of building height. While smoke spreads vertically so rapidly, evacuation speed is too slow, therefore the reasonable measure for the safe of egress route is urgent. Existing pressurizing smoke control system of vertical exit route is seriously limited in function under the stack effect in winter. Stack effect in winter could be overcome with the methods of opening the staircase outward or letting airflow be free between staircase and outside.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.208-212
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• 2002

난간대가 사용되는 곳은 건설현장, 건물 외에도 제조현장, 제조공장 등 사람이 가는 곳, 작업자가 통과하는 곳에는 어디서나 존재한다고 보면 될 것이다. 산업안전보건법의 안전기준 제27조에서는 사업주는 4단 이상의 계단에 개방된 측면에는 난간을 설치하고 다음 각 호의 조치를 하여야 한다 1) 난간의 높이는 90cm 이상이 되도록 할 것 2) 난간은 계단참을 포함하여 각 층의 계단 전체에 걸쳐서 설치 할 것. 3) 목재로 된 난간은 5제곱cm 이상의 단면을 금속제 파이프로 된 난간을 4cm 이상의 지름을 갖는 것일 것. 4) 난간은 임의의 점에 있어서 임의의 방향으로 움직이는 100kg 이상의 하중에 견딜 수 있는 튼튼한 구조로 할 것 5) 난간의 지주는 2m 이내마다 설치하고 가능한 한 단면과 난간 상면과의 중앙부에 중간대를 설치할 것으로 규정하고 있다. 상기 사항에서 3)항은 구조적으로 중요한 요소로서 외부하중에 대한 내력상의 문제가 있을 것으로 판단되어 이에 대한 실험규명이 필요하게 되었고 본 연구의 목적이 되었다.

• Journal of Korea Water Resources Association
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• v.46 no.3
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• pp.245-252
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• 2013

The reflection coefficients of monochromatic water waves over various shear currents flowing on a constant topography are estimated analytically in this study. The region of varying shear currents is represented by a finite number of tiny steps with a uniform depth topography. The proper numbers of steps and evanescent modes needed for the analysis are proposed by a series of convergence tests. The characteristics of reflection coefficients for various shear currents conditions are also examined.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.319-325
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• 2017

The scenography in terms of directorial viewpoints could suggest the overall vision of scripts rather than providing stage design only. I chose Antonio Buero Vallejo' because he presented the spatial characteristics and images clearly and believe that it could be an exciting challenge to change its original scenography that the playwright suggested. The concept of failed social success and enclosed repeated destiny spaces gave shape to my scenography of stairs. I chose every character in this play had to climb a flight of stairs in order to go outside because a main and sole entrance was located on the top floor. Characters' visual movement which went up in the morning for their dreams, but came down disappointedly due to failure day by day. This concept of scenography became the characters' given circumstances and intended to always affect the characters' acting during the show. Finally, I verified a new scenographic possibility beyond theoretical examination because I applied it to practical production.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.83-89
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• 2011

A series of full-scale testing was conducted to examine the effect of stairwell pressurization on the pressure differential between the stairwell and the auxiliary room and between the auxiliary room and the residence. Also, flow velocity profiles at open doors were measured. The building tested was a condominium that had twenty floors above the ground and two floors underground. For pressurization of the stairs, a blower was used to supply air into the stairwell at one location underground. Thirteen different cases were tested, and test variables included the number of floors with open doors and the flow rate of the air supply. When the doors on the first floor were open, the pressure differential between the stairwell and the auxiliary room was distributed almost uniformly except for locations near the first floor. When the flow rate was in the range of 180~270 CMM and the doors of one floor were open, the flow velocity could satisfy the requirement of fire safety standards and the stairwell pressure was positive at all levels. However, the minimum pressure requirement (10 Pa) could not always be satisfied. When doors on two floors were open, the flow velocity requirement could be satisfied by increasing the flow rate, but it was found impractical to satisfy the minimum pressure requirement without causing excessive pressure differential in the area near the blower.

• Journal of the Korea Institute of Building Construction
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• v.14 no.6
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• pp.571-581
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• 2014

In the present study, hollow precast concrete wall (PC Double Wall) for staircase construction was developed. Comparing the conventional walls, the PC Double Wall can be reduced the lift weight using hollow core and improves the integrity between the PC members. The cross-section and re-bar details of the PC Double Wall were developed considering precast concrete manufacturing, constructability, and the structural safety. Particularly, a form system was developed to manufacture thin and hollow core PC wall efficiently. A mock-up test for a staircase using the PC Double wall was performed to verify the constructability and integrity of the PC walls. The test result verified that joint deformation and cracking did not occur as showing good constructability.

• Fire Science and Engineering
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• v.24 no.4
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• pp.109-115
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• 2010

Maximum pressure difference in central core type 80th super_tall buildings was estimated as 75 Pa during no outside wind due to the winter stack effect. Maximum pressure difference of 225 Pa can be obtained depending on the location of air injection fan during the stairway pressurization at fire. Bottom_only air injection system provided the best results in the sense of required air flow rates and pressure distributions. Top_only air supply system was estimated as the worst for this country. It revealed that the decrease of the temperature in the stairway due to the cold outside air injection reduced the required flow rates of the fan and significantly changed the distribution of pressure differences.

• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.175-182
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• 2020

The calculation of the optimal trajectory of the stepped top-down robot was made using a genetic algorithm and a computational torque controller. First, the total energy efficiency was minimized using the Red-Cold Generic Algorithm (RCGA) consisting of reproductive, cross, and mutation. The reproducibility condition related to the position assembly of the start and end of the stride and the joints, angles, and angular velocities are linear constraints. Next, the unequal constraint accompanies the condition for preventing the collision of the swing leg at the corner with the outer surface of the stairs, the condition of the knee joint for preventing kinematic peculiarity, and the condition of no moment in safety in the traveling direction. Finally, the angular trajectory of each joint is defined by fourth-order polynomial whose coefficient is to approximate chromosomes. This is to approximate walking. In this study, the energy efficiency of the optimal trajectory was analyzed by computer simulation through a biped robot with seven degrees of freedom composed of seven links.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.18-31
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• 2018

It is important to conduct various analyzes to evacuate occupants in advance, because the disaster can cause serious injury. Therefore, it is necessary to analyze all the predictable scenarios that may occur. In this study, we propose a method to analyze the evacuation of indoor disaster using activity - based transport model MATSim. We have developed the university building as target area and simulated about 5,000 occupants. The analysis scenarios are set as basic evacuation conditions, exit closures and emergency stair closures. As a result of analysis of each scenario, the evacuation time was analyzed to be about 5:40(340s) in the base scenario, increased by 15% in the scenario 2 and increased by 23% in scenario 3. As a result of this study, we suggest that it is important to manage illegal obstacles of emergency stairs for rapid evacuation. Therefore, this study can contribute to the effective disaster prevention strategy of the building.