• Korean Journal of Environment and Ecology
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• v.8 no.2
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• pp.154-159
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• 1995

The Chuwang valley-Kumunkwangi valley forest in Chuwangsan area was studied to investigate forest structure in relation to altitude and part of slope. Forty eight quadrats were set up in the valley forest along altitude of 470m to 780m and part of the slope. Density and basal area of trees in tree strata decreased as increasing elevation. With increasing elevation the importance values of Quercus mongolica, Fraxinus rhynchophylla increased, while those of Pinus densiflora, Lindera obtussiloba decreased. As going from lower part to upper part of the slope, the importance values of Quercus valiabilis and Lindera obtussiloba increased while those of Fraxius rhynchophylla, Acer mono decreased. Species diversity tended to decreased as going to upper parts of the slope. The range of similarity indices between elevation belts, and parts of the slope were 74.4~84.2% and 68.0~96.3%, respectively. According to importance value and cluster analysis, the studied valley forest was classified into three forest communities of Pinus densiflora-deciduous tree species community of lower part of slope, Pinus densiflora-Quercus variabilis community of middle and upper part of slope, Pinus densiflora community of the top area.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.5
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• pp.325-330
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• 2013

The patient's appearance can be dramatically enhanced as a result of orthognathic surgery. However, esthetic contouring of the mandibular body portion is often overlooked in the surgery. Restoring a more beautiful jaw line is important and directly affects surgical results. From December 2010 to February 2012, we performed mandibular body contouring for the slimming of the third lower part of the face in 37 patients who had undergone either 1-jaw surgery or 2-jaw surgery. The third lower part of the facial contour was improved in all the patients after at least 3 months follow-up. Mandibular body contouring is a simple method that can be additionally used for the slimming of the third lower part of the face in patients who require orthognathic surgeries. It makes the lower face look more attractive from both the anterior and lateral perspectives.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.5
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• pp.502-510
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• 2000

Evaporation heat transfer characteristics were studied in a horizontal tube using R22/R114 non-azotropic refrigerant mixture. the heat transfer coefficient was high in the upper part for pure refrigerants, and heat transfer coefficient was low in the lower part for refrigerant mixtures. In the low quality region where nucleate boiling was dominant, the average heat transfer coefficient was low. In the region where forced convection was dominant, heat transfer coefficient was high. Results show that the heat transfer coefficient for pure refrigerants obtained by experiments were lower than those of Yoshida et al. but agreed well with Jung et al., and Chen et al. data. But the heat transfer coefficients for refrigerant mixtures were lower about 20% than those predicted by the equation for pure refrigerant.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.6
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• pp.1-6
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• 2010

Aluminum rear lower arm is designed for luxury sedan and manufactured by hollow sand casting in the present study. Here we present the relationship between local microstructure and coupon tensile test in the rear lower arm. The characteristics of the local tensile deformation are supposed to be dependent upon Si distribution and DAS (dendrite arm spacing). Si distribution affects the yield strength and DAS affects the elongation of local area in the part, respectively.

• 한국해양학회지
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• v.30 no.4
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• pp.302-319
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• 1995

The geochemical properties, sedimentation rates, foraminiferal distributions, and oxygen and carbon isotope records of sediment from Cores S-2 and S-19 were studied to investigate late Holocene paleoceanographic and paleoclimatic changes of the admiralty and Maxwell Bay, King George Island, Antarctica. Total organic carbon contents increased from the lower part to the upper part of Cores S-2 and S-19, whereas calcium carbonate contents decreased from the lower part to the upper part of Cores S-2 and s-19,whereas calcium carbonate contents decreased from the lower part to the upper part of Cores S-2 and S-19. Twenty-seven foraminiferal species were identified, and Globocassidurina biora was mostly a bundant in sediment samples. The sedimentation rates ranged from 24 cm/kyr to 237 cm/kyr based on /SUP 14/C-age dating of G. biora. The sedimentation rates increased rapidly in the upper part of the Cores. б/SUP 18/O values ranged from 0.3% to 6.2% and б/SUP 13/C values ranged from -3.0% to 0.0% with several fluctuations of the values. The lowest part of Core S-2, at 128 cmbsf in depth, had a /SUP 14/C-age of 3,100${\pm}$60 yr B.P. and the lowest part of Core S-19, at 230 cmbsf in depth, of 7,400${\pm}$ yr B.P. The results of geochemical and sedimentological analyses of the core sediments suggested five stages of paleoceanographic and paleoclimatic changes as follows: war,-cold stage of 7,500∼6,500 yr B.P., cold stage of 6,500∼3,600 yr B.P., cold-warm stage of 3,600∼2,770 yr B.P., warm stage of 2,770∼2,380 yr B.P. and cold-warm stage of 2,380∼2,100 yr B.P.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.215-222
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• 2011

The purpose of this study was to analyze the effects of the use of the lower extremity supporter to ground reaction force(GRF) & EMG in women. Five women participated in the experiment conducted in the study(age: $46.7{\pm}3.5$ yrs, weight: $52.3{\pm}2.2$ kg, lower extremity height: $74.1{\pm}0.9$ cm, knee height: $40.7{\pm}1.4$ cm). The Ground reaction force was measured by AMTI ORG-6 and the Muscle activity of the lower extremity was measured by an 8-channel surface EMG system(Noraxon Myoresearch, USA, 1000Hz). We statistically compared muscle activity and ground reaction force with and without the lower-extremity supporter by one-way repeated ANOVA. The results were as follows. First, the use of the lower extremity supporter affects the ground reaction force along the anterior-posterior axis(Y). Second, the vertical(Z-axis) reaction force on the upper part of the lower extremity supporter increase because of the difference between the interval of vertical movement. Third, the muscle activity of the lateral gastrocnemius and rectus femoris was higher in the upper part of the lower extremity supporter. Further research for example, on a comparative analysis of joint moments, the effects of direct stressor on joints. and the relationship between muscle activity and joint movement, is necessary for a better understanding of the effects of the lower-extremity supporter.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.58-64
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• 2004

The shrinkages of injection molded parts are different in molding operational conditions, resins and additives. The shrinkage of injection molded part for crystalline polymer, PBT (polybutylene terephthalate) has been studied for various operational conditions of injection molding and content of additives. Mica was used as a additive to PBT to examine the part shrinkage according to the mica content. The part shrinkages of mica contained PBT decreased as mica content increases. Higher injection temperature and injection pressure resulted in a lower shrinkage. As mold temperature increases the part shrinkage decreased. The part shrinkage of flow direction was less than that of the perpendicular direction to the flow for both pure and mica contained PBT. However the shrinkage difference between flow and perpendicular to flow directions decreased as mica content increased.

• International Journal of Air-Conditioning and Refrigeration
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• v.13 no.1
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• pp.1-10
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• 2005

Screw compressor chillers are widely used in refrigeration for capacity over 30 RT. In general, chillers operate under part-load conditions during most of the time. Therefore, information on the characteristics of part-load is very important for better chiller performance and energy economy. In this study, performance tests of screw chiller with economizer using R22 and R407C under part-load conditions have been performed for various secondary fluid temperatures. Adoption of an economizer system increased the cooling capacity and improved COP except for lower part-load condition when economizer volume ratio is 1.01. For the same cooling capacity condition at part-load, COP's of both non-economizer and economizer system showed similar values.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.11
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• pp.902-909
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• 2003

Screw compressor type chillers are widely used in refrigeration for capacity over 30 RT. In general, chillers operate under part-load conditions. Therefore, information on characteristics at part-load is very important in view of chiller performance and energy economy. In this study, performance tests of part-load and economizer system using R22 and R407C have been performed for various secondary fluid temperatures. Adoption of an economizer system increased the cooling capacity and improved COP except for lower part-load condition when injection volume ratio is 1.01. For the same cooling capacity condition at part-load, COP of both non-economizer and economizer system showed similar values.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.1-12
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• 2006

Distributions of water temperature and DO profiles were investigated in Andong Reservoir from 1992 to 2004. Thermal stratification began to form from May of every year. Increasing water temperature of epilimnion, temperature difference between epilimnion and hypolimnion increased until August. Lower oxygen layer was formed at metalimnion from June or July of every year and there were 2 layers depending on each year. The two lower oxygen layers were affected by rainfall and inflow between July and September when thermal stratification was formed. The metalimnetic oxygen minima strongly formed at 2 layers, upper and lower part, when the average rainfall and inflow were ${\geqq}$ 170 mm, ${\geqq}$ 50 $m^3\;sec^{-1}$, respectively. It formed weakly when they were > 400 mm and > 200 $m^3\;sec^{-1}$ for one month. The upper part of low oxygen layers formed on the interface of epilimnion and metalimnion showed larger decreasing rate of DO than temperature and it disappeared around November. The lower part of those farmed on interface of metalimnion and hypolimnion existed until December and disappeared in January, this layer showed larger decreasing rate of temperature than DO. DO increased between the upper and lower part of the low oxygen layers. DO on hypolimnion increased under metalimnion and dramatically decreased near the bottom of the reservoir. Temperature of the inflow during rainy season was similar to that of the reservoir's metalimnion, DO was similar or higher and BOD, COD and SS increased. Density layer caused by turbidity was formed in metalimnion, and turbidity increased under the upper part (oxygen increasing layer) of metalimnetic DO minima layers reaching the maximum at the direct upper part of the lower DO minima layer. The upper part of DO minima layers formed on the interface of epilimnion and metalimnion is related to organic activity on the surface, and the lower part of those was considered to be the result of turbid water inflow to metalimnion during rainy season.