• Proceedings of the KSME Conference
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• 2001.11b
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• pp.493-498
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• 2001

In the low velocity displacement air-conditioning system, the conditioned air is supplied from the diffuser placed on the wall near the floor and vented near the ceiling. This system has some advantages upon the traditional mixing system; the air quality near the people is improved by the displacing action of the system and the energy may be saved by neglecting the cooling or heating load for the upper space of the space above the people. This study is to examine the temperature and velocity distributions in the room and near the diffuser. It is found that the temperature is stratified uniformly all over the room space to show the displacing function of the system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.231-232
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• 2006

The purpose of this study is to measure and evaluate the thermal conditions of large cruiser's cabin. As the result of this study, followings are cleared. The air volume supplied to the 2 types of cabins is quite diffenrent. Temperature differences in the Room A which is located A deck and supplied enough air volume is stable all around the cabin. But Room B which is located B deck and supplied comparatively small air volume has temperature distribution problems, like time-dependent differences, vertical differences. To serve more comfort and productivity of Room B, it is strongly recommended to do a T.A.B.(Testing, Adjusting and Balancing) for more air volume and/or to design new air flow path to make air stay longer.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.669-674
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• 1997

A sound field in a reverberation room is analyzed by using numerical methods and the SPL distributions are compared to the measurements. In numerical predictions, the BEM is employed in the low frequency range, while sound ray tracing method is used for the high frequency range. In the BEM analysis, the surfaces of the empty reverberation room are assumed as rigid boundaries and the damping coefficients are estimated from the measured absorption coefficient. The comparisons with measurements for 100Hz shows good agreement. In the sound ray tracing analysis, the predicted energy decay are in excellent agreements with theoretical results. It is shown that the energy absorption by air damping plays an important role as frequency becomes higher.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.2 no.4
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• pp.303-315
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• 1990

Uniformity of velocity is quite important design points of a vertical laminar flow type clean room. In the present paper, flows in a room with a bottom pannel are numerically simulated by using a low-Reynolds number $k-{\epsilon}$ model, and a new flow model of the pannel are suggested. Resistance coefficient of the pannel and size of the exhaust channel show considerable effects on flow pattern and uniformity of flow on the bottom. Reflection coefficient also has important roles. A possibility to obtain the uniform and unidirectional flow is tested by adjusting the distribution of resistance coefficient of the pannel. Such a numerical simulation of the flow will be a good method to get optimun design parameters.

• Journal of Powder Materials
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• v.6 no.1
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• pp.111-118
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• 1999

Ni(Fe)Al powders containing a homogeneous distribution of the in-situ formed AIN and $Al_2O_3$ dispersoids have been produced by mechanical alloying process in a controlled atmosphere using high energy attrition mill. The powders have been successfully consolidated by hot extrusion process. The phase information investigated by TEM and XRD analysis reveals that Fe can be soluble up to 20% to the NiAl phase ($\beta$) at room temperature after MA process. Subsequent thermomechanical treatment under specific condition has been tried to induce secondary recrystallization (SRx) to improve high temperature properties, however, the clear evidence of SRx was not obtained in this material. Mechanical properties in term of strength at room temperature as well as at high temperatures have been improved by the addition pf AIN, and the room temperature ductility has been shown to be improved after heat treatment, presumably due to the precipitation of second phase of $\alpha$ in this material.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.9
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• pp.853-859
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• 2001

A pulsed tracer gas technique is applied to measure distributions of local mean age and residual life time of air in a half-scale experimental chamber. The room airflow patterns are flow-visualized by a Helium bubble generator for three different exhaust locations. A supply slot is located at the top of a right wall, and an exhaust slot is either at bottom-left(Case 1), bottom-right(Case 2), or top-left(Case 3) location. Results show that the distribution of LMA and LMR are different from each other, but both of them are closely related to the airflow pattern in the space. Results on overall room ventilation effectiveness are provided depending upon ventilation airflow rates for three different supply-exhaust configurations.

• Journal of the Society of Naval Architects of Korea
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• v.48 no.1
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• pp.62-66
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• 2011

The present work focuses on the evaluation of thermal comfort in passenger cabin of a cruise ship. A computational fluid dynamics (CFD(Airpak)) is used to calculate air velocity and temperature distribution in the passenger cabin as well as PMV and PPD. The CFD is used to simulate two different cases, room unit system and wardrobe duct system. Both of cases are simulated in summer environment condition. The room unit system and wardrobe duct system are compared and evaluated by ISO 7730 thermal comfort categories. The performance of room unit system is shown to be more effective for this typical case of passenger cabin.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.484-491
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• 1997

In this paper, an approach to determine the in-ordinal condition of a room, which is based on multi variable analysis, is proposed. According to this approach, the distance of a state from the ordinal condition is thought to be evaluated by the Mahalanobis' distance. The temperature changes of a room were measured and their statistical characteristics such as distribution type, the mean value and the standard deviation are studied. The applicability of the method for the fire detection is also investigated.

• The Journal of Korean Medicine
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• v.28 no.3 s.71
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• pp.197-206
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• 2007

Objectives : By recording basic data of patients visiting the emergency room of the oriental medicine center, we can understand their characteristics and gain better insight about them. Methods : We performed a retrospective study of 2,674 patients who visited the emergency room of Kyunghee Oriental Medical Center, from June 1, 2006 to May 31, 2007. Results : 1. Of 2,674 total patients, the male to female ratio was 0.94:1 and the 6th decade of life was the peak age group. 2. The majority of patients visited our emergency room between 06:00 and 24:00(midnight). 3. Most patients visited on a Saturday or Sunday. 4. By monthly distribution, the patients increased slightly during June, July, August and October. 5. The majority of patients visited the emergency room within 24 hours of onset. 6. The patients were categorized as follows: neurological diseases 71.15%, musculoskeletal diseases 16.02%, internal medical disease 9.04%, psychiatric and related disease 3.79%. 7. The average transit time was about 1 hour 30 minutes. 8. Admission rate was 48% and the rate of admission to the intensive care unit (ICU) was 5% of total visiting patients. Conclusion : Assuming that this research will continue adding patient's data continuously, this work will help us to understand the features of patients who visiting the emergency room of the oriental medical center.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.4 no.2
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• pp.75-83
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• 2009

Objectives : By recording basic data of musculoskeletal patients visiting the emergency room of an oriental medicine hospital. we can understand their characteristics and gain better insight about them. Method : We performed a retrospective study of 551 patients who visited the emergency room of an oriental medicine hospital, from November 1,2008 to October 31, 2009. Result : 1. Of 551 total patients, the male to female ratio was almost same and the 3rd decade of life was the peak age group. 2. The majority of patients visited emergency room between 10:00 and 24:00(midnight). 3. Most patients visited on a Saturday or Sunday. 4. By monthly distribution, the patients increased slightly during January, May and October. 5. The majority of patients visited the emergency room within 24 hours of onset. 6. The patients were categorized as follows : lumbar sprain 66.06%, cervical sprain 16.25%, ankle sprain 9.04%. 7. Admission rate was 21.96%. Conclusion : Assuming that this research will continue adding patient's data continuously, this work will help up to understand the features of musculoskeletal patients who visiting the emergency room of the oriental medicine hospital.