• 설비공학논문집
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• 제11권6호
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• pp.871-879
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• 1999

Present study explains some experimental results on the aerodynamic noise of the cross-flow fan usually installed in the indoor unit of the room air-conditioners and provides a simple reduction method of radiating sound to decrease the total noise level. The spectrums of the noise of the cross-flow fan were analyzed by the spectral decomposition method to characterize the generated sound. The unsteady fluctuating flow field was also measured using the I-type hot-wire probe. Comparing the spectral characteristics of the sound and the flow velocity, a useful noise reduction method was proposed which bounds the region with a fence where the flow fluctuations were noticeably changed in the same fashion as the source spectral distribution functions vary. To validate the proposed method for reducing noise generated by the cross-flow fan, the sound pressure levels of the cross-flow fan system were compared of the experimental rig with and without the bounding fence for various flow rates.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.462-467
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• 2000

The aim of this study is to provide fundamental data for acoustic design by analyzing the room acoustic characteristics according to the PA system used in the school gymnasium. The measurements were carried out accordance with the ISO 3382. The sources used in this study were four types; omni-directional, centralized, distribution, the combination of centralized and distribution sound source system. Omni-directional system is recommended by ISO for the acoustic test and the others are installed on the wall, column and ceiling in the school gymnasium for sound reinforcement.

• 한국해양공학회지
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• 제13권3B호
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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.

• 대한기계학회논문집B
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• 제29권7호
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• pp.868-877
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• 2005

We performed the experimental and the numerical study on the comparison of thermal comfort performance indices for cooling loads in the lecture room for 4 cases: Fan coil unit(FCU) or 4-way cassette air-conditioner is respectively operated with the ventilation system or without. We measured the velocity, the temperature distribution and predicted mean vote(PMV) value in the lecture room for 4 different air-conditioning methods. Effective draft temperature(EDT) and PMV were investigated to analyze the characteristics of two thermal comfort indices in the lecture room and to compare their values each other. From the results we knew that there is the similarity between PMV values and EDTs when the room is air-conditioned for cooling loads. It turned out that definition of the control temperature is very important when the EDT is calculated. Finally EDT should not be used to predict the accurate thermal comfort in case that the temperature and humidity are suddenly varied and the zone affected by the solar and inner wall radiation.

• 대한디지털의료영상학회논문지
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• 제13권1호
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• pp.21-26
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• 2011

A radiation imaging system used in a surgery room is mainly using C-arm which is purposed to fluoroscope. C-arm is often use to watch an operation's accuracy and progress, but not only being bombed to this first beam but also affected to this scattered beam, so now we are look for the way to reduce bombed amount of doctor, nurses and radiological technologists. We measured the exposure dose in $0^{\circ}$ spot according to the distance to find out frequency distribution of scattered ray in an operation room and found the spot which has the same exposure dose from $30^{\circ}$ distance of all directions and wrote isodose curve. We analyzed the data and found out the sudden reduction of scattered ray according to the long direction also found out that scattered ray was not related to the directions. Operators must recognize the reduction of exposure dose. Because reducing scattered ray from all directions in an operation room is really difficult. So every operators must use shelters to reduce the exposure dose and notice the safety.

• 한국병원경영학회지
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• 제28권3호
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• pp.39-46
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• 2023

Purpose: Korean medical services are not balanced across regions and social classes. To prevent mortality gaps, Korea must distribute its medical resources more efficiently. Patient factors affecting emergency room visits serve as basic data for determining best practices for public healthcare distribution. Methods: The data included 18 473 visits by 14 949 de-identified patients who visited a public emergency room over one year. The dependent variable was the number of emergency room visits. A Poisson regression was conducted with the independent variables, comprising sociodemographic, socioeconomic, and spatial accessibility factors and patient characteristics. Results: Older men with higher Korean Triage and Acuity Scale scores visited more frequently. Greater patient-hospital distance decreased visits; however, the presence of a hospital within 1 km of a patient's residence did not affect the number of visits. The use of 119 services was negatively correlated with the number of visits. Visits increased with more medical benefits. Conclusions: Patient age, distance to hospital, use of 119 services, and medical benefits should be considered when planning or managing public hospitals in Korea.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 동계 학술대회 논문집
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• pp.395-401
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• 2000

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권6호
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• pp.561-566
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• 2008

This is a retrospective clinical study on 2,955 patients who had visited the Emergency Room of Sang-gye Paik Hospital and then been treated in the Department of Oral and Maxillofacial Surgery during recent 4 years from Aug. 2002 to Dec. 2006. The obtained results were as follows. The total number of patients was 2,955 and the ratio of male to female was 1.72:1. The age distribution peak was the 1st decade (30.8%), followed by the 3rd decade (14.3%) and the 4th decade (14.0%). Trauma (62.3%) was the most frequent cause in dental emergency patients, pulpitis (13.0%) and infection patients were next in order of frequency. In trauma patients group, facial bone injury, tooth injury, soft tissue injury were included and soft tissue injury group was most prevalent, followed by tooth injury group and facial bone group. In total patient, the ratio of admission was 3.5%. We obtained the results of the distribution of primary emergency care in the traumatic injury, causal distribution of the jaw fracture, distribution of related medical department in multiple associated injuries, distribution of emergency care in infection, causal distribution and control methods of oral bleeding, distribution of TMJ disorder. The trauma patient group was major in the dental patients who had visited the emergency room, but other various groups were included. So we should analyze the pattern and the variation of the dental emergent patient to provide the proper treatment.

• 설비공학논문집
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• 제18권1호
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• pp.7-16
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• 2006

Both the computational and experimental analysis have been conducted in this study to develop the high efficiency agriculture products dryer by the uniform thermal flow distribution in the drying room. It has been developed based on the results of the computation and experiment in the conventional dryer to improve the thermal flow distribution in drying room. The developed dryer can be prevented the local concentration of the heated wind and achieved the uniform flow distribution using the installation of vertical branch ducts, ribs, guide vanes and porous plates. As a result, the developed dryer reduced the fuel consumption up to $15\%$ and the electricity consumption up to $31.5\%$ compared with the conventional dryer.

• 한국태양에너지학회 논문집
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• 제28권6호
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• pp.48-57
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• 2008

The research analyzed the distribution of the indoor temperatures of a radiant floor cooling system through mock-up experiments. It investigated the temperature difference of feed water, the vertical temperature difference of indoor air, the temperature difference of floor surface, and so on. The following is the results of the research. First, the research shows that the difference between indoor temperature and outside temperature was the smallest when the temperature of feed water was set at 16$^{\circ}C$. In addition, the temperature changes according to indoor positions (wall, room, floor, and ceiling) were the most uniform. Thus, the research found that the cold water temperature of 16$^{\circ}C$ is the most proper. In addition, it confirmed that the feed water temperature of 18$^{\circ}C$ is effective because the temperature can lower the temperature of a room to 13.55$^{\circ}C$, which is lower than the temperature of a non-cooling mode. Second, an investigation on the temperature distribution of vertical air in indoor space shows that the temperature distribution had a difference of 0.2 to 1.9$^{\circ}C$ on the average, which satisfies the range of 3.0$^{\circ}C$ in the standard of ISO.