• 전기의세계
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• v.22 no.1
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• pp.20-27
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• 1973

The multi-group diffusion theory is applied to the analysis of the currently constructing Kori reactor core which is to be refuelled by 3-region fuel loading pattern and also to the comparative study on a conceptually designed 5-region reactor core, under the condition that, apart from the thermal-hydraulic considerations, all the input data referred to here in are assumed to be identical for both cases. The numerical calculation is carried out for quantitative analysis of the characteristics of the two fuel loading patterns in details, and the calculated results show that, so far as the nuclear aspects are concerned, the characteristics of the 5-region reactor core are proved to be superior to those of Kori's 3-region reactor core in general.

• Journal of the Korean housing association
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• v.26 no.1
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• pp.81-90
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• 2015

The purpose of this study was to investigate housing characteristics of young renter households by locations using licensed microdata of the 2012 Korea Housing Survey. There were 1,020,216 renter households (weighted count) headed by persons between 20 and 34 years of age, and their housing characteristics were compared statistically across their residential locations (Capital Region, metropolitan cities, other areas). Major findings are as follows: (1) Capital Region young renters had the worst housing quality to have the greatest proportion of households living in units failed to meet national minimum housing standards, and/or in basement or semi-basement units; (2) Capital Region young renters had the greatest proportion of households that had housing cost burdens; and (3) 37.3% of young renter households in metropolitan areas and 33.5% in Capital Region were found to receive family support in order to afford current rental costs.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.6
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• pp.102-108
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• 2011

The flow characteristics of unventilated dual impinging jets were experimentally investigated. Two nozzles with an aspect ratio of 20 were separated by 6 nozzle widths. The Reynolds number based on nozzle width and nozzle exit velocity was set to 5,000. A Particle Image Velocimetry (PIV) was used to measure turbulent velocity components. It was found that, when an impingement plate was installed in the converging region, there was a stagnation region in the inner area between nozzles. However, when it was installed in the combined region, both jets were merged and collided into the plate, showing single-jet characteristics. In addition, at a dual impinging jet, as the distance between a nozzle and an impingement plate decreased, the spanwise turbulent intensity at the plate increased.

• Physical Therapy Korea
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• v.9 no.1
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• pp.69-79
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• 2002

Many pregnant women have experienced low back pain (LBP) during pregnancy and after delivery, and it has been an important component in women health. This study was designed to investigate the characteristics and management of the LBP in postpartum women. Eighty-five postpartum women were participated in this survey. Mean age of 85 women was 28.1 years. Of 85 postpartum women, 55.3% (n=47) had LBP after pregnancy. Thirty of 47 women had pain on lumbar region, 17 postpartum women had pain on sacroilium region. Of 85 postpartum women, 74% (n=54) had LBP before pregnancy and 71.8% (n=61) had LBP during pregnancy. Of 47 postpartum women who had LBP, 83% (n=39) had not received medical management for LBP, 12.8% (n=6) took medication, and 4.3% (n=2) performed self-exercise. None of postpartum women had received physical therapy during pregnancy and after delivery for treatment low back pain. The pain in SI region was more severe than in lumbar region after pregnancy according to VAS (visual analog scale) (p<.05). However, there was no significant difference in VAS scores between SI pain and lumbar pain before and during pregnancy (p>.05). Pain region after delivery was related to pain region of pre-pregnancy and during pregnancy (p<.01). Pain level after delivery was related to the pain and night pain level during pregnancy (p<.01).

• Proceedings of the Korean Society of Rural Planning Conference
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• 1998.10a
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• pp.25-27
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• 1998

The objective of this study is by analyzing villages("Ri" units) to specify the proper unit of the area that the rural development policy is suitable for, and to examine whether the current rural development policy considers the characteristics of community and region. The study included twelve districts(in Korean "Eup" or "Myun") and one hundred one villages(in Korean ri) in Poryong-si, Chungchungnam-do. Twelve and fifteen variables are respectively employe for the analysis of Myun`s and Ri`s. Using Factor Analysis, Cluster Analysis, and Z-Score Analysis, the study examines the degree of disadvantage and the process of growth pattern of each Myun or Ri. The Ri`s are also classified according to their functional characteristics. The results of this study could be summarized as follows; 1) There exist some problems in the current rural development policy because it does not take into consideration the characteristics community and region. 2) Except a few distinct of areas, the proper unit of the area for the rural development policy should be set being based on regional characteristics rather than the administrative units. 3) The spatial boundary of rural development policy should be sets from villages(ri) to beyond the unit of administrative units("Si" or "Gun"), according to the village unit analysis. 4) It is needed that community and region data should be consistently accumulated after specifying Standard Statistical Districts. 5) The application of indicators should be in accordance with the characteristics of the policy.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.6
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• pp.133-144
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• 2018

To suggest the field maintenance plan considering the geographical characteristics of the region, we selected representative regions(plain regione and mountain region) and compared spatial distribution of cultivated land in Muan-gun and Hwasun-gun. Firstly, we examined the distribution characteristics of cultivated land according to the scope of the maintenance object with Fragstats. As a result of that, it was found that the cultivated area except rice paddy had the highest aggregation effect. And then, we developed type classification of maintenance considering geographic characteristics and cultivated crops information. As a result of classification, plain land type Muan region was mostly cultivated land suitable for integrated maintenance. On the other hand, Hwasun, a mountainous terrain, needs small-scale maintenance and road maintenance. Based on these results, it was found that more detailed planning is needed for the upland field infrastructure improvement considering the topographic characteristics.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.12
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• pp.1078-1087
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• 2003

Kimchi refrigerator is a household electric appliance developed with the wholly domestic technology for maturing and keeping kimchi. However, the principle of keeping is not yet revealed obviously. This numerical study has been conducted to investigate the flow and heat transfer characteristics in a kimchi refrigerator. The effects of arrangement variation of a evaporation tube are examined. Also, the heat transfer characteristics through the insulation material are discussed in detail. The flow and temperature field was simulated using the commercial code of CFX-5.3. A natural convection flow is formed through about 5/6 region from the bottom within the keeping space and accordingly, the 90% region of kimchi containers satisfies the temperature requirement with 0$\pm$0.5$^{\circ}C$. The stagnant flow exists in the upper 1/6 region of the keeping space and accordingly, the stratified high temperature distributions appear in the upper region of kimchi containers. The upward shift of the start location of a evaporation tube improves the temperature concentration toward $0^{\circ}C$ but the pitch variation is of no effect. The heat fluxes on the insulation surfaces show two-dimensional distributions with being higher toward the center. Through the variation of insulation thickness, 3.5% saving of insulation material is obtained under the same heat transfer rate.

• Journal of Environmental Science International
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• v.23 no.9
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• pp.1551-1562
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• 2014

To clarify the characteristics of TKE (Turbulence Kinetic Energy) variation for offshore wind power development, several numerical experiments using WRF were carried out in three different coastal area of the Korean Peninsula. Buoyancy, mechanical and shear production term of the TKE budget are fundamental elements in the production or dissipation of turbulence. Turbulent kinetic energy of the south coast region was higher than in other sea areas due to the higher sea surface temperature and strong wind speed. In south coast region, strong wind passing through the Korea Strait is caused by channelling effect of the terrain of the Geoje Island. Although wind speed is weak in east coast, because of large difference in wind speed between the upper and lower layer, the development of mechanical turbulence tend to be predominant. Since lower sea surface temperature and smaller wind shear were detected in west coastal region, the possibility of turbulence production not so great in comparison with other regions. The understanding of the characteristics of turbulence in three different coastal region can be reduced the uncertainty of offshore wind construction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.05a
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• pp.137-140
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• 2003

The flow characteristics of secondary recirculation region in a liquid fuel ramjet combustor are measured using PIV method. The model combustor has two rectangular inlets that form 90 degree angle each other. The tested angles of the air intakes were 30, 45 and 60. Three guide vanes are installed in each rectangular inlet to improve the flow stability. The experiments are performed in the water tunnel test with the same Reynolds number as the case of Mach 0.3 at the inlet. PIV software is developed to measure the characteristics of the flow field in the combustor. The accuracy of the developed PIV program is verified with rotating disk experiment and standard data. The experimental results show that the secondary recirculation flow occurred at the front junction of inlet main stream and combustorchamber. The size of secondary recirculation regions are increased with increasing air inlet angles. Since the performanceof combustor is very dependant on not only the main recirculation in the dome region but also the secondary recirculation flow in a junction region, the optimal angle of the air intakes should consider the both recirculation size as a frame holder.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.1
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• pp.9-16
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• 2003

According as the industry was developed, the pollution of the environment and atmosphere rose up to the surface. So, the focus is now concentrated on the engines of affinity for nature. And the investigators make more effort to the improvement in the performance of engines, depending to the prices of oil and the anxiety about the exhaustion of the fossil fuel go up. So the GDI engines head up for these necessities. In this experimental study, the spray flow characteristics for a commercial injector equipped in the present GDI engine were investigated, which had a strong influence on the engine performance and emissions. The experiment was performed at the injection pressures of 1, 3, 5 and 7MPa under the atmospheric condition. A PDPA system was used to specify the flow characteristics of the spray. Also, the global spray behavior classified into three regions as leading, main spray and vortex cloud region, was analyzed by using a visualization system. And the regions were compared with each other.