• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.627-636
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• 2008

The purpose of this study is to develop the new korean district heating system for apartment houses. The upper & lower side ondol system with multi sensing control system was developed as a new korean district heating system and evaluated in 2 mock-up laboratories last winter. As a result of field measurement, when the load differences between perimeter zone and central zone are increased, the ondol system divided in the upper and lower side can be evaluated as the new ondol system with a capability for suppling proper heating energy for each zone. The user can have the freedom for changing an upper zone and a lower zone and controlling each temperature according to their needs.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1990.10a
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• pp.28-34
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• 1990

Lighting is one of the largest energy, integrated lighting system with daylight and artificial lighting has been suggested. In such system, perimeter zone can be illuminated by daylighting and the deep area of room by artificial lighting. So, the study is to develope estimation nomograph of lighting energy by turnning-off depth and lighting control systems during daytime. For the purpose, energy nomograph has been developed to apply to side-lit office guilding and the use and limitation of the nomograph has been discussed.

• Proceedings of the SAREK Conference
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• 2004.06a
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• pp.104-104
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• 2004

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.12
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• pp.1204-1211
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• 2004

It is difficult to apply a conventional selection guide for diffusers when the diffuser is installed in a perimeter zone, because the air diffusion performance index (ADPI) vs. throw/length (T/L) ratio curve listed in conventional guide does not consider the perimetric heating load through the walls. The objective of this study is to evaluate the effect of the perimetric heating load on the ADPI and propose a selection guide for a proper line diffuser when perimetric heating load exists. The velocity and temperature distributions and the ADPI values are obtained numerically with various heat load ratios and air flow rates. The velocity and temperature distributions and the ADPI values are analyzed by CFD in case of various heat load ratios and air flow rates. Also, ADPI was calculated by those results. The ADPI values by numerical results are compared with an existing experimental data to verify the method for the evaluation of ADPI proposed in a present study. In case of a line diffuser installed at the high side wall, the ADPI decreases according to the increases of the flow rate on every heat load ratio of the present study except 0.75. The ADPI vs. T/L ratio curves have been proposed for the heat load ratios of 0.25, 0.5, 0.75 to guarantee the comport thermal environment when diffusers are installed in perimeter zone.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.906-911
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• 2008

Because the perimeter of buildings is strongly influenced by solar and the outdoor air temperature, the area has different environmental properties compared to the interior of a building, as in summer heat gain, and in winter heat loss. In particular, if the external wall is glass, the characteristics of the glass material make it pervious to outside conditions, thereby making big changes to the thermal environment. By combining shading device and the efficient exhaust system, an energy saving can be achieved compared to no air barrier systems. The simplified air barrier system is developed with the idea that energy could be conserved by carefully and effectively blowing out the air caught between the glass surface and the roller blind. The way it is configured is therefore by making the roller blind's air-path, and by placing the air output ducts in the most optimum positions. This simplified air barrier system will give improvement in the thermal environment of the parameter area that is strongly affected by solar and the outdoor condition.

• Explosives and Blasting
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• v.37 no.3
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• pp.25-33
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• 2019

Controlling the blast-induced damage zone(BDZ) in mining excavation is a significant issue for the safety of employees and the maintenance of facilities. Numerous studies have been conducted to accurately predict the BDZ in underground mining. This study employed the dynamic fracture process analysis (DFPA) to estimate the BDZ from a single hole blasting. The estimated BDZ were compared with the results obtained by Swedish empirical equation. The DFPA was also used to investigate the control mechanism of BDZ and fracture plane formation around perimeter holes for underground mining blasting.

• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.1
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• pp.95-107
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• 1985

This study is purposed to investigate the role of grasses as the Green Foundation effect on the visual preference to flowering tree and shrub being the principal elements of natural landscape early in the spring. As the flowering shrub materials, Rhododendron mucronulatum and Forsythia Kreana were adopted. Total 48 slides were photographed at the 8 different lawn areas with the 6 planting combinations of flowering shrub materials, and 10 landscape variables - dimensional and color - were measured and preference scores were taken by slide evaluations. The results were : 1) The visual preference to the landscape of flowering shrub in the lawn area was changed with the different lawn situations. 2) With important 4 variables, multilinear regression model was established, hence Y =40.4 + 9.6($X_1$) -7.8($X_2$) -26.8($X_3$) + 15.2($X_4$) where, Y : estimated preference score $X_1$: perimeter of flower zone $X_2$: value of green covered zone $X_3$: hue of green covered zone $X_4$: chroma of green covered zone 3) Most effective variable was 'hue of green covered zone', hence the more green the lawn area ism the more preferred landscape or the more effective green foundation is.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.144-148
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• 2001

A geophysical and geochemical study was performed to verify the depth of landfill as well as the horizontal/vertical distribution of leachate at the landfill site located in Gongju. The electrical resistivity, with dipole-dipole array and dipole spacing of 5m, was applied along the nine survey lines and electromagnetic induction survey was conducted along the perimeter traverse surrounding the landfill. Cations, anions and stable isotope ($\delta$D and $\delta$$^{18}$ O) analyses were performed on about 63 water and leachate samples collected in dry and rainy seasons at 31 sites. The result of electromagnetic induction survey make it possible to derive the potential route of leachate in the past or present. The imaging of processed resistivity field data show that the possible route of leachate doesn't exist except the survey line 7. The weak zone traversing the landfill, however, is revealed by the electrical resistivity imaging, which may be the potential route of leachate toward the deep ground. The geochemical data agree well with geophysical data for deducing possible route of leachate of the site.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.2
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• pp.62-68
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• 2001

It is a serous subject for energy conservation to prevent the energy loss caused by the mixture of heated and cooled air jets in perimeter and interior zone of a building operated with tow kinds of air-conditioning system simultaneously. The purpose of this paper is to clarify the quantitative and qualitative mechanisms of mixing loss and to propose a evaluation method for it. By using the dynamic heat load calculation, heat extraction load of a typical office building in Busan are calculated. According to the results, numerical simulations based on CFD(Computational Fluid Dynamics) were performed in order to evaluate mixing loss in the physical size of HVAC system. Then, the distributions of air temperature and airflow patterns according to the differences of set-point temperature are analyzed to grasp relations how to influence mixing loss.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.10
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• pp.879-885
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• 2000

It is a serious subject for energy conservation to prevent the energy loss caused by mixing of heated and cooled air jets in a building which two types of air-conditioning systems are adopted in perimeter and interior zone. The purpose of this paper is to clarify the quantitative and qualitative mechanisms of the mixing loss and to propose preventive methods for it. In this paper, by using the dynamic heat load calculation method, heat extraction loads of a typical office building in Pusan are calculated. According to the results, numerical simulation based on the computational fluid dynamics were peformed in order to measure the mixing loss in physical size HVAC system. Then, the distributions of air temperature and velocity are analyzed in order to grasp the relations by setting temperature differences influence on the mixing loss.