• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 춘계 학술대회논문집
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• pp.119-122
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• 2005

In this paper a method for analysing aerodynamic characteristics of a rotating parachute in steady descending motion is presented. Because of a complex geometric configuration of the parachute associated with side vents and discontinuous skirts, special procedure was adopted th handle the geometry in the analysis. A panel method was successfully applied to the present problem and yielded good results using above procedure. A CFD code using the full Navier-Stokes equations was also applied and provided good results. Parachute free drop and wind tunnel tests were performed to determine the fully developed canopy configuration and aerodynamic characteristics. The method can be used for optimizing the parachute size and side vent configurations in the design period.

• 한국전산유체공학회지
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• 제11권1호
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• pp.52-56
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• 2006

In this paper a method for analysing aerodynamic characteristics of a rotating parachute in steady descending motion is presented Because of a complex geometric configuration of the parachute associated with side vents and discontinuous skirts, special procedure was adopted to handle the geometry in the analysis. A panel method was successfully applied to the present problem and yielded good results using above procedure. A CFD code using the full Navier-Stokes equations was also applied and produced good results. Parachute free drop and wind tunnel tests were performed to determine the fully developed canopy configuration and aerodynamic characteristics. The method can be used for optimizing the parachute size and side vent configurations.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.970-975
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• 2008

This study considers indoor thermal comfort in an ondol space by supply vent configurations to prevent cold draft in winter. A specially-designed vent cap has been investigated in comparison with a round pan-type vent and a simple opening without a cap. Numerical simulations have been conducted using CFD to analyze thermal comfort indices such as Predicted Mean Vote (PMV) and Effective Draft Temperature (EDT) as well as air distribution index i.e. Air Diffusion Performance Index (ADPI). Results show the new vent cap provides improved thermal comfort conditions especially near ondol heated floor, as the cold outdoor air spreads upwards along the vertical wall before reaching occupant region near floor. This paper includes discussions on the flow and comfort distributions created by the thermal jets from the vents.

• 대한수의학회지
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• 제31권3호
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• pp.235-240
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• 1991

The abnormal male Newhampshire of five months age with three hindlimbs was examined macroscopically and radiographically The external feature included two normal wings, two normal hindlimbs and an underdeveloped extra hindlimb, which was attached to the pelvic region. The extra hindlimb consisted of an underdeveloped femur like bone, tibiotarsus likebone, tarsometatarsus like bone and three rows of digits with claw. The femur like bone was fused with pelvic girdle like bone. The bones of extra hindlimb were fused into one except one row of digit, which was attached to the tibiotarsus like bone. Three ceca and one cloaca with two vents were also observed.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.249-252
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• 2000

To overcome problems of excavation technology far repairing or replacing underground buried pipes which are worn out or damaged, various trenchless repair-reinforcement technologies have been invented. But these trenchless technologies also have many problems in the aspect of economy and convenience of operation. In this research, the repair-reinforcement process using RTM (Resin Transfer Molding) which can solve problems of present trenchless technologies was developed. The resin wetting and void removal during RTM process to form large composite structures inside of buried pipes were experimentally investigated. From the experiment, it was found that the new technology had advantage over conventional methods by employing appropriate process parameters and void removal vents.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.557-560
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• 2008

Window system is an essential component for ventilation, lighting, and thermal environment in buildings. However, window system has the lowest insulation performance and may cause high energy consumptions, if it is not properly designed. Thus, performance of window systems play an important role in built environment. This study proposes a new window systems for balcony, which has double vents and analyses the thermal performance using an intergrated simulation method with Therm 6.1 and Widow 6.1. The result shows higher U-factor than conventional window systems. It is expected that the double vent window system can increase thermal performance and save energy in apartment houses.

• 한국철도학회논문집
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• 제10권1호
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• pp.67-73
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• 2007

Experiments were carried out to investigate smoke movement in platform of a subway station which currently is in service in Pusan, the second largest city in Korea. The recently constructed underground station of the "bank type" (two platforms on both sides of track) which is the popular layout of platforms in Korea, is chosen in Pusan. The smoke generator and heater are used for simulating the smoke movement at the fire break in the platform located in the 2nd basement of the station. Video recordings were used to monitor smoke lowering. In this study, the movements of smoke in the underground station are investigated under various smoke-control operating modes. Three tests wire conducted according to its operating mode of the ventilation systems in the platform: no operation of any ventilation systems, smoke extraction mode in occurrence of fire (presently running mode) and full capacity of smoke extraction where all vents are activated in the platform. The results can be used for comparing with the numerical prediction results of fire subway stations.

• Advances in aircraft and spacecraft science
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• 제3권1호
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• pp.77-93
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• 2016

In this paper, a zero-dimensional mathematical formulation for rapid and explosive decompression analyses of pressurized aircraft is developed. Air flows between two compartments and between the damaged compartment and external ambient are modeled by assuming an adiabatic, reversible transformation. Both supercritical and subcritical decompressions are considered, and the attention focuses on intercompartment venting systems. In particular, passive and active vents are addressed, and mathematical models of both swinging and translational blowout panels are provided. A numerical procedure based on an explicit Euler integration scheme is also discussed for multi-compartment aircraft analysis. Various numerical solutions are presented, which highlight the importance of considering the opening dynamics of blowout panels. The comparisons with the results from the literature demonstrate the validity of the proposed methodology, which can be also applied, with no lack of accuracy, to the decompression analysis of spacecraft.

• Animal Systematics, Evolution and Diversity
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• 제39권1호
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• pp.47-52
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• 2023

Thermopolynoe Miura, 1994 is a monotypic genus in Lepidonotopodinae that comprises species endemic to chemosynthesis-based ecosystems. Here, we examined T. branchiata collected from the hydrothermal vents in the North Fiji Basin. For the first time in Thermopolynoe, we report sexual dimorphism detecting nephridial papillae on segments 11-13 in males, additionally describe the morphology on elytra with round to conical microtubercles on the surface, and distinguish presence of small neuropodial lobes on segments 3-26. We also revised couple of errors and ambiguities in the original description: incongruence between the description and figure and existence of individual variation in ratio of tentacular cirri and palps. In addition, three COI sequences of T. branchiata specimens from the North Fiji Basin were newly obtained and sequences divergence with other Lepidonotopodinae species were determined. These results would contribute to the taxonomy of polynoids in a chemosynthesis-based ecosystem.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.235-236
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• 2022

In the present study, the effect of horizontal vent position on fire phenomena in the enclosure with vertical and horizontal vents was examined using numerical simulation. Case 1 indicates the condition that the horizontal vent is in the center of the ceiling. Case 3 indicates the condition that the horizontal vent is far away from the vertical vent. Case 2 indicates the condition that the horizontal vent is installed between Case 1 and Case 3. The temperature distribution, smoke layer temperature, velocity distribution, and mass flow rate of horizontal vent flow were analyzed. In Case 2, the temperatures were lowest and the mass flow rate through the horizontal vent was largest. This is because the flame is inclined by the inflow through the vertical vent. Hence, to determine the proper horizontal vent location for the high smoke ventilation performance, the inflow through the vertical vent and its effect on flame behavior should be considered.