• Journal of Environmental Science International
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• v.12 no.6
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• pp.677-688
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• 2003

The purpose of this study was to predict occurrence of earthquakes in Korea by measuring the concentration of radon radioactivity in the air and in the underground water. Two monitoring systems of radon concentration detection in the air were installed in Seoul, East Coast area, whereas of radon concentration in the underground water in Kyungju area during December, 1999 to June, 2001. The distribution of radon concentration in the air in Seoul is as follows Winter(10.10 $\pm$ 2.81 Bq/㎥), autumn(8.41 $\pm$ 1.35 Bq/㎥), summer(5.83 $\pm$ 0.05 Bq/㎥) and spring (5.34 $\pm$ 0.44 Bq/㎥), whereas the distribution of radon in the air in the East Coast area showed some difference as follows : autumn (14.08 $\pm$ 5.75 Bq/㎥), Summer (12.04 $\pm$ 0.53 Bq/㎥), Winter (12.02 $\pm$ 1.40 Bq/㎥) and spring (8.93 $\pm$ 0.91 Bq/㎥). In the meanwhile, the distribution of radon in the water is as follows : spring (123.59 $\pm$ 16.36count/10min), Winter (93.95 $\pm$ 79.69counter/10min), autumn (68.96 $\pm$ 37.53counter/10min) and spring (34.45 $\pm$ 9.69counter/10min). The daily range of the density of radon concentration in Seoul and East Coast area was between 5.51 Bq/㎥ - 9.44 Bq/㎥, 7.15 Bq/㎥ - 15.27 Bq/㎥, respectively. Correlation of the distributions of radon concentrations in the air and in underground water with earthquake showed considerable variations of radon concentration before the occurrence of the earthquake. The results suggested that radon radioactivity seemed to be helpful for the prediction of the occurrence of earthquake.

• Journal of Animal Environmental Science
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• v.4 no.2
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• pp.127-136
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• 1998

To use the earth heat for the livestock housing, an underground heat exchanger is developed and pipes are layed in the depth of 2.5m under the ground. The pipes have two different kinds of diameter (200mm, 100mm) and materials (PE, PVC). The results of heating effect in winter and spring are following. The temperature in different soil depth varies from 5$^{\circ}C$ by 1.5m depth, to 9$^{\circ}C$ by 3.5m. So it should be better to have the depth greater than 2.5m. The difference of air temperature between the inside and outside pipe was 9.9 Kelvin(K) with 200mm diameter and 13.4K with the 100mm diameter with the same material in winter. By the lower outside temperature from -7.2$^{\circ}C$, it could keep the air temperature above 6$^{\circ}C$ through the 100mm diameter pipe. The heating performance was 593 W with 200mm diameter, 118W with 100mm diameter (PE), and 115W with 100m diameter (PVC), respectively. As the outside temperature varies from -1.5$^{\circ}C$ to 18.6$^{\circ}C$ in early spring, the air temperature through the pipes show 4∼8$^{\circ}C$. While the difference between maximum and minimum outside temperature is 14K, the one through the pipes could be reduced by 2K. Pipes with small diameter can more reduce the difference than the pipe with larger diameter.

• Asian Journal of Atmospheric Environment
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• v.2 no.1
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• pp.60-67
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• 2008

The spatial limitations of urban environments in general lead to invention and design of a wide range of underground transportation systems such as subways, underground roads and paths, etc. Among them, the application of subway systems in metropolitan cities is most commonly observed to ease those confronted difficulties on this purpose. It in turn leaves passengers and workers to be exposed to indoor air potentially polluted by various sources existing in this underground environment. Specifically when considering the IAQ in a subway station, there exist many IAQ-related parameters to be counted either as individual or as integrated exposures. In this study, a model system has been developed to manage the general IAQ in a subway station. Field survey and $CO_2$ measurements were initially conducted to analyze and understand the relationship between the indoor and outdoor air quality while considering the internal pollution sources such as passengers, subway trains, etc. The measurement data were then employed for the model development with other static information. For the model development, the algorithm of simple continuity was built and applied to model the subway IAQ concerned. In this paper, the recent updated draft version of model developed will be reported and demonstrated.

• Journal of the Korea Furniture Society
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• v.23 no.4
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• pp.381-387
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• 2012

Utilization of underground floor is becoming the main issue of our society to maximize and diversify the potential of recent urban space. It has brought about the changes of underground floor. Recently there are lots of huge bookstores in these underground floor. Bleach, adhesive and ink used for manufacturing books pollute indoor air in bookstore. Therefore, the purpose of this study is to analyze indoor air quality in these large bookstores. Concentrations of carbon dioxide and formaldehyde in three large bookstores in Seoul were measured by presence and type of books and distance of main entrance which is well-ventilated. According to the data, space that places lots of volumes measured higher concentration of formaldehyde than that of non-existence books. Children's book section was measured more concentration of formaldehyde than other book section. Closer main entrance near outside, lower concentration of formaldehyde was measured. Concentration of carbon dioxide was affected by the number of people in bookstore.

• Journal of Power System Engineering
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• v.16 no.2
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• pp.30-35
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• 2012

The geothermal energy is one of the renewable energy sources which can contribute in accomplishing a vision and goal of the national plan on energy for a government suggestion. Especially, the geothermal energy is evaluated as the nearly unlimited resources. The yearly underground temperature distribution by depth is very important to the design of air-conditioning system which uses a geothermal energy. Furthermore, there has no data for comparisons to numerical analysis. In this study, the yearly underground temperature is measured under the depth of 2 m in Tongyeong, and these data are compared with numerical analysis results for checking the accuracy. The results showed that the experimental temperature and numerical results had a good agreements and these results will be utilized to predict a performance of air-conditioning system for using a geothermal energy.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.4
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• pp.263-276
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• 1992

The transmission current in a power cable is determined under the condition of separate pipe cooling. To this end, the thermal analysis is conducted with the standard condition of separate pipe cooling system, which constitutes one of the underground power transmission system. The changes of transmission current in a power cable with respect to the variation of temperatures and flow rates of inlet cooling water as well as the cooling spans are also determined. As a consequnce, the corresponding transmission current is shown to vary within allowable limit, resulting in the linear variation of the current for most of the cable routes. The abrupt changes of current, however, for the given flow rate of inlet cooling water in some cooling span lead to the adverse effects on the smooth current transmission within the underground power transmission system. In practice, it is expected that the desinging of the separate pipe cooling system in conjunction with the evaluation of system capacity should take into account the effects of design condition on the inlet cooling flow rate.

• Journal of the Korean Society of Safety
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• v.25 no.6
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• pp.98-102
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• 2010

LPG (Liquefied Petroleum Gas) vehicles in metropolitan area are being applied to improve air quality and have been proven effective for the reduction of air pollutant. In addition, the demand of gas as an eco-friendly energy source has being increased. With the LPG filling station is also increasing every year. These gas stations are required to install the securest storage tank because of possibility of causing huge loss of life and property. Therefore, in this paper, underground containment type is proposed as installation of the LPG storage tank using Taguchi method, which is considered to be more safe, economical, efficient, easy checking and simple construction method than any other. If leakage, economics, real estate utilization rate, safety, easy to check, simple construct about above ground, buried underground and underground containment storage tank are analyzed by Taguchi method, real estate utilization rate, economic and safety in turn are improved. Therefore, the underground containment storage tank is a optimal installation technology.

• Journal of Environmental Science International
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• v.13 no.3
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• pp.215-222
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• 2004

This study was conducted to evaluate the characterization of airborne bioaerosol in public facilities in Seoul. A total of 17 public facilities were investigated from December, 2002 to February, 2003. As results of the survey, the mean concentrations of bacteria and fungi in indoor air of public facilities were $378.08\pm296.33$ CFU/㎥ by RCS and $106.38\pm171.63$ CFU/㎥ and $347.46\pm335.32$ CFU/㎥ and $95.23\pm62.61$ CFU/㎥, by Six-stage cascade air sampler respectively. The mean concentrations of bacteria in indoor air (by ventilation method) were $517.14\pm343.93$ CFU/㎥ of natural ventilation and $215,83\pm100.71$ CFU/㎥ of mechanical ventilation. The mean concentrations of fungi in indoor air (by ventilation method) were $83.14\pm79.16$ CFU/㎥ of natural ventilation and $133.50\pm248.07$ CFU/㎥ of mechanical ventilation. The mean concentrations of bacteria in indoor air were 449.44 CFU/㎥ for the ground and $217.50\pm103.68$ CFU/㎥ for the underground. The mean concentrations of fungi in indoor air were $63.89\pm77.66$ CFU/㎥ for the ground and $202.00\pm290.08$ CFU/㎥ for the underground.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.128-137
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• 2002

This study was conducted to develop the heat exchanger by utilizing the heat energy of underground water(15℃), which might be used for cooling and heating system of the agricultural facilities. We developed the heat exchanger by using the parallel type plat fin tube made of Aluminum(Al 6063), which was named Aloo-Heat(No. 0247164, offered by Korean Intellectual property Office). The trial manufactures were made from Aloo-heat which was 600mm, 700mm length respectively, and It were welded to the end "U" type in order to direct flow of the underground water. The performance test was carried out under the condition of open space and room temperature with the change of flow rate of the underground water and air. The results are as follows. 1. The trial manufactures had convection heat value from 33 to 156 W/m²℃, and It was coincided with design assumption. 2. The amount of energy transfer was increased with the increment of the area of heat transfer, the air flow, the gap of temperature inlet & outlet the underground water and the air. 3. The heat value was 6,825W when the air flow was 6,000m³/h and the gap of temperature between inlet and outlet of the underground water was 6℃, and It dropped from 25.8℃ to 23.2℃(-2.6℃ difference). The convection heat value was 88.5W/m²℃. 4. The heat value was 2.625W when the air flow was 4,000m³/h and the gap of temperature between inlet and outlet the underground water was 2℃, and It dropped from 27℃ to 22.5℃(-4.5℃ difference). The convection heat value was 33.6W/m²℃. 5. Correlation values(R²) of the testing heat values of the trial manufacture type I, II, and III were 0.9141, 0.8935, and 0.9323 respectively, and correlation values(R²) of the amount of the air flow 6,000m³/h, 5,000m³/h, 4,000m³/h were 0.9513, 0.9414, and 0.9003 respectively.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.113-117
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• 2009

By statistics in August, 2007, currently Korean motors registration number broke through 16 million units. The demand of motors is being increased as time goes on and the demand of parking lot within apartment complex is increased together. Therefore, it is inevitable to expand underground parking lots. Underground parking lots have relatively weaker environment than the ground and physical/psychological problems as distance far away from the main building, fear for vehicle damage and crimes, impure air, darkness and closed feeling take place. Underground parking lots also occupy a lot of area ratio within apartment complex and have a lot of effects on other facilities. Therefore, underground parking lots are neglected for all that underground parking lots have deep relations with satisfaction for public space within apartment complex. Accordingly, the purpose of the study is to make reference materials when underground parking lots are planned by grasping satisfaction of underground parking lots through inhabitants'mental survey and surveying preferential location and requirements of parking lots.