• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.275-280
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• 1998

인간의 감성에 영향을 미치는 요인은 다양하나 이 중에서도 열환경은 인간에게 미치는 정도가 어떠한 요인보다도 큰 것으로 알려져 있다. 열환경이라 함은 온도, 습도, 기류, 복사열을 말하며 이 요소들과 인간의 감성과는 밀접한 관련을 지닌다. 열환경과 관련된 인간의 감성을 측정, 평가하기 위해서는 주위의 열환경이 정밀하게 제어되는 공간에서 작업이 이루어져야 한다. 실내 공간의 열환경을 임의로 제어하기 위해서는 급기되는 공기의 조건과 벽체의 온도가 정밀하게 제어되어야 한다. 공기와 벽체 조건은 가열, 냉각, 가습 또는 제습에 의하여 정밀하게 제어되며 이를 실현하기 위하여 공조 시스템은 일반적인 시스템과는 달리 특수한 조건이 요구된다. 공조 시스템의 각 구성요소가 컴퓨터에 의해 개별적으로 제어될 수 있어야 하며 특수 조건에 따른 유연성이 뛰어나야 한다. 본 연구에서는 열환결 제시에 적합한 공조 시스템을 개발한다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.7
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• pp.470-477
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• 2008

The near-optimal control algorithm for central cooling system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling control system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.2
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• pp.9-14
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• 2000

State feedback with integral control for a variable air volume(VAV) unit which is recently taken notice of for the energy efficiency and saving in the building is studied to investigate the performance of the digital control methodology for the possible practical application. The digital controller which acquires the targat zone temperature and the air flow rate of the supplied air to the zone controls the opening of the damper in the VAV unit. Simulation results are performed for the conditions including reference changes and external thermal variations. In the simulation. simplified conditioned zone and the damper actuator modelling is considered. and relationships between controller gain Parameters and the system dynamics are investigated.

• Fire Science and Engineering
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• v.18 no.4
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• pp.64-71
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• 2004

This paper describes the result of the pump room fire analysis of the nuclear power plant using CFAST fire modeling code developed by NIST. The sensitivity studies are performed over the input parameters of CFAST: the constrained or unconstrained fire, Lower Oxygen Limit (LOL), Radiative Fraction (RF), and the opening ratio of the fire doors. According to the results, a pump room fire is the ventilation-controlled fire, so it is adequate that the value of LOL is 10% which is also the default value. It is anlayzed that the Radiative Fraction does not affect the temperature of the upper gas layer. It is appeared that the integrity of the cable located at the upper layer is maintained except for the safety pump at the fire area and the Conditional Core Damage Probability (CCDP) is 9.25E-07. It seems that CCDP result is more realistic and less uncertain than that of Fire Hazard Analysis (FHA).

• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.50-54
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• 2006

A fire in a subway station platform, completely isolated by screen doors, was numerically simulated to investigate problems in smoke control and find their countermeasures. A part of the platform, $40m{\times}5m$ floor and 3 m high, and a fire of 1 MW were considered, and the smoke extraction system was assumed to start operation at the onset of the fire. For three different values of the exhaust air flow rate, 0.1, 2, and $4m^3/min-m^2$, the distributions of temperature, concentrations of soot and carbon monoxide, and those of visibility were compared. The time-variations of the number of randomly distributed particles in the space were also investigated for the air flow rates to see the efficiency in smoke control. It was shown that smoke control takes time by lack of air supply. It was also confirmed that air supply from the railway to the platform at emergency is needed so that smoke is able to be controlled efficiently, and that opening the doors at the both ends of the platform is desirable until the fire is completely extinguished.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1523-1528
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• 2008

In this study, the ventilation system of connection passage and elevator hall of underground parking lot in apartment houses is investigated to extract the data for the installation and the application by the experimentation. In case of the elevator hall, actual air exchange rate is predicted fivefold higher than air exchange rate by infiltration and exfiltration. Ventilation system is installed good by supply air and return air. As the next best thing, it is installed by supply air because of IAQ control. The temperature of connection passage and elevator hall uniformly with $7{\sim}8^{\circ}C$, is maintained even if the operating condition of ventilation system is different. Therefore, the installation of the preheater, which is installed at the inlet of ventilation system for the cold draft in winter, is not essential in southern area of Korea.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.6
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• pp.63-69
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• 2018

The machine learning model can capture the dynamics of building systems with less inputs than the first principle based simulation model. The training data for developing a machine learning model are usually selected in a heuristic manner. In this study, the authors developed a machine learning model which can describe supply air temperature from an AHU in a real office building. For rational reduction of the training data, the progressive sampling method was used. It is found that even though the progressive sampling requires far less training data (n=60) than the offline regular sampling (n=1,799), the MBEs of both models are similar (2.6% vs. 5.4%). In addition, for the update of the machine learning model, the normalized mutual information (NMI) was applied. If the NMI between the simulation output and the measured data is less than 0.2, the model has to be updated. By the use of the NMI, the model can perform better prediction ($5.4%{\rightarrow}1.3%$).

• Journal of Ocean Engineering and Technology
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• v.13 no.3B
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• pp.29-37
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• 1999

Ventilation of the marine engine room is very important for the health of the workers as well as the normal operation of machines. To find proper ventilation conditions of this engine room, numerical simulation with standard k-${\epsilon}$ model was carried out. In the present study, the marine engine room is separated to two floors with porus horizontal partition and considered as a closed space with a heat source and forced ventilation ducts. The porosity of horizontal partition is found to be important. For the engine room with 2 supply ports & 2 exhaust ports, the increasing of the porosity of horizontal partition is effective to reduce the recirculation flow zone in the second floor. When the engine room is ventilated with three supply air ports & one exhaust port, the increasing of the porosity of horizontal partition is effective to reduce the recirculating flow zone in the exhaust air area, but there is a possibility of local extreme heating at the lower side of engine near bottom.

• Fire Science and Engineering
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• v.22 no.5
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• pp.29-34
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• 2008

In this research, to establish the emission for the people who are clearing out, through the numerical analysis using the CFD model, the dangerousness has been investigated in the various emission conditions in a station platform. As a result of research, it is found out that the temperature variation falls between 65.37% and 74.97% to compare without installation of platform screen doors. In the addition, with the supply mode or push-pull mode, the warm current is generated in the platform so the temperature and the layer of smoke are stirred up and felled off. It will make the dangerousness when the people escape. Therefore, when the capacity of emission and the space of platform is set up, the design regards the properties of the fire emission.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.1
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• pp.100-107
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• 1998

Ventilation of the marine engine room is very important for the health of the workers as well as the nomal operation of machines. To find proper ventilation conditions of this engine room, numerical simulation with standard k-.epsilon. model was carried out. In the present study, the marine engine room is considered as a closed space with a heat source and forced ventilation ducts. The injection angle of air supply is found to be important. Injection with downword angle depresses recirculation flow, causing a strong steam in the wider space of the room. Ventilation and removal of the released heat are promoted with this pattern. There is a possibility of local extreme heating at the upper surface of engine when supply and exhaust ports of air are in bilateral symmetry. The effect of the increase of exhaust port area on ventilation decreases as the number of supply port increases.