• Journal of the Society of Naval Architects of Korea
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• v.42 no.4 s.142
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• pp.402-410
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• 2005

This paper focused on the analysis of the thermal comfort conditions in 1,000 ton class patrol ship's cabins through the evaluation of PMV(predicted mean vote) and PPD(predicted percentage of dissatisfied). Different areas have different clothing and activity in the ship. Therefore, any area may be thermally uncomfortable in case of air conditioning with equal temperature, relative humidity and relative air velocity. PMV or PPD-DCAC (demand controlled air conditioning) system is a new design that the whole cabins are maintainable with the ideal thermal comfort condition.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.2
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• pp.28-44
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• 2015

Granite soil has been used traditionally as a school playground surface. Natural turf has also been used in some schools. Recently artificial turf has come into common use instead of granite soil or natural turf. Artificial turf playgrounds are used at 174 schools in Seoul, Korea. More than 3,500 artificial turf fields are installed in the United States. Because of the increase of artificial turf usage, there are many studies about the estimation of artificial turf effects to environment. Compared with artificial turf material effects such as characterization of substances released from material, and recognition of volatility of heavy metal into the surrounding environment - air or the percolating rainwater -, less studies for thermal effects of artificial turf playground have been done. Especially, the corresponding studies in Korea are few. Thus, the purpose of this research is to compare the thermal effects of artificial turf on school playground between natural turf and granite soil. In this study, air temperature and Predicted Mean Vote (PMV) were compared in three scenarios by Computational Fluid Dynamics (CFD) model. Additionally, the results were validated through a field measurement. Air temperature decreasing effects by natural turf are greater than those by artificial turf and granite soil at 14:30 on 20th, July 2011. It shows the same decreasing effects at 23:30. However, the difference is less than that of daytime. PMV differences between natural turf and the other two surface covers are large at daytime while those are much less at nighttime. Consequently, air temperature and PMV of artificial turf are the highest among three school playground surface pavements.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.3
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• pp.240-246
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• 2006

This paper performed to investigate on vertical temperature distribution, effective draft temperature (ETD) and PMV (Predicted Mean Vote) in the classroom, which is located YangSan city (Kyungsangnam-Do), Korea, is equipped with ceiling unit. The vertical temperature difference between F.L+10 cm (ankle) and F.L+120 cm (neck) of a measuring point which is adjacent corridor in the classroom showed about $1^{\circ}C$ but of measuring point which is adjacent outdoor expressed up to $4^{\circ}C$, The effective draft temperature (ETD) is -2.3 and -0.52 and 0.67 at near ceiling unit but is 1.2 and 3.3 at far from ceiling unit. The PMV of total classroom showed the range of 'Cold' and 'Slightly Cold.' Therefore, to achieve comfort condition in the classroom is equipped with ceiling unit, the location of ceiling unit and discharge angle and discharge distance from ceiling unit are very important elements.

• Journal of Biosystems Engineering
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• v.34 no.1
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• pp.1-7
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• 2009

In order to evaluate environmental comfort of tractor cabs, temperature, relative humidity and noise within the cab were taken from 31 tractors during plowing and rotovating operations. The temperature and humidity were evaluated with regard to the comfort zone of KS B ISO 14269-2 and PMV of ISO 7730. The noise was evaluated with regard to the permissible sound level of OSHA for daily exposure of 8 hours. The collected data indicated that thermal environment of the cabs was out of the comfort zone, which meant tractor operators worked under uncomfortable thermal conditions. Difference in the thermal comfort by tractor power and maker, and type of works was not found. However, 25% of the studied tractors showed PMV in a range of -0.5 to +0.5, which indicated their operators worked under the comfort criteria. PMV was improved when the cab was air-conditioned. Levels of measured cab noise were lower than the permissible criteria, and 76.7% of the studied tractors had cab noise ranged from 75 to 85 dBA. There was a tendency that high powered tractors, rotovating operations and locally-made tractors had greater cab noise levels. However, their differences were insignificant.

• Journal of Sensor Science and Technology
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• v.12 no.1
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• pp.24-33
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• 2003

This research is about a comfort sensing system for human environmental monitoring using a one-bodied humidity and temperature sensor and an air flow sensor. The thermal comfort that a human being feels in indoor environment has been known to be influenced mostly by six parameters, i.e. air temperature, radiation, air flow, humidity, activity level and clothing thermal resistance. Considering an environmental monitoring, we have designed and fabricated a one-bodied humidity and temperature sensor and an air flow sensor that detect air relative humidity, temperature and air flow in human environment using surface micromachining technologies. Micro-controller calculates a PMV (predicted mean vote) and CSV (comfort sensing vote) with sensing signals and display a PMV on LCD (liquid crystal display) for human comfort on indoor climate. Our work has demonstrated that a comfort sensing system can provide an effective means of measuring and monitoring the indoor comfort sensing index of a human being. Experimental results with simulated environment clearly suggest that our comfort sensing system can be used in many applications such as air conditioning system, feedback controlling in automobile, home and hospital etc..

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.1
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• pp.32-39
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• 2003

Thermal comfort in the Rotunda which is high wide visiting space of the new national museum of Korea has been numerically investigated in this paper. To evaluate thor-mal comfort of the Rotunda, well-known indices, PMV and PPD were introduced. The results of present investigation show that thermal comfort is satisfied at the breathing zone of the visiting space. However a thermal stratification with $9^{\circ}C$ of temperature difference occurs along the height of the Rotunda which makes the thermal environment worse. For example, the PPD value reaches up to 50% in the 6th floor connection passage. Consequently, additional HVAC design factors should be considered in order to reduce the large thermal stratification.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.4
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• pp.221-229
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• 2008

This study analyze indoor thermal comfort properties such as PMV, PPD and fluid variables when the cooling loads are light, occupant and ventilation. There are 6 cases to study for the indoor unit installation conditions and ventilation rates. Numerical method is used to study the indoor environmental properties and experimental study is adapted to analyze reaching time by variable cooling load conditions.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.297-300
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• 2006

Various buildings constructed by environmentally friendly resources are being built in KOREA. Especially the building made by the wood, which has environmental characteristics that the reinforced concrete and brick doesn't have, are acknowledged with its superiority. Then, studies on indoor thermal control capability of the wooden building and influence of its indoor environment to sensory environment of occupants are not enough proceed. Thus, there were proceeded 24 hours measurements for indoor and outdoor thermal environmental elements of Log Cabins and the hourly subjective tests to evaluate indoor amenity of occupants in this study. The results of the study are following: 1) Upon evaluation on thermal environment elements, indoor and outdoor dry bulb temp were 22.0$^{\circ}C$ and -2.9$^{\circ}C$, and Indoor and outdoor average relative humidity were 25.8%and 52.7%. Differences of indoor and outdoor temperature and humidity were 24.9$^{\circ}C$ and 26.9%. 2) Upon contrastive analysis between the results of subjective tests, warm and cold sensation vote, and PMV (Predicted Mean Vote) and PPD (Predicted Percent Dissatisfaction), values of subjective tests W.9

• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.214-222
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• 2017

Objectives: A hospital is a complex building that serves many different purposes. The indoor environment in a hospital plays a major role in patient well-being and the work efficiency of the hospital staff. This study was conducted to evaluate overall comfort in two major hospitals over the course of one year. Methods: Various indoor environmental conditions were measured in two general hospitals for one year (April 2014 to April 2015). Monitoring alternated between the hospitals at one month per respective monitoring session. The indoor air temperature, relative humidity (RH), mean radiant temperature and air velocity were measured in order to calculate the predicted mean vote (PMV). Carbon dioxide concentration, noise level and illumination level were concurrently measured and applied to the overall IEQ acceptance model for the hospitals (IEQh). Results: The IEQh at the two general hospitals was different at five spaces within a building. The IEQh for summer and winter were significantly different. Real-time IEQh demonstrated that indoor comfort was affected by the hospital's operating hours due to operation of the HVAC system. The percentage of indoor comfort in the hospitals was higher using PMV than IEQh. Conclusion: IEQh in the hospitals was different at locations with different purposes. Indoor comfort assessment using IEQh was stricter than with PMV. Additional research is needed in order to optimize the IEQh model.

• Proceedings of the SAREK Conference
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• 2008.06a
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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.