• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.1
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• pp.1-13
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• 2011

The Yellow Sea Cold Water (YSCW) is formed by cold and dry wind in the previous winter, and is known to spread southward along the central trough of the Yellow Sea in summer. Water characteristics of the YSCW and its movement in the northern East China Sea (ECS) are investigated by analyzing CTD (conductivity-Temperature-Depth) data collected from summertime hydrographic surveys between 2003 and 2009. By water mass analysis, we newly define the North Western Cold Water (NWCW) as a cold water mass observed in the study area. It is characterized by temperature below $13.2^{\circ}C$, salinity of 32.6~33.7 psu, and density (${\sigma}_t$) of 24.7~25.5. The NWCW appears to flow southward at about a speed less than 2 cm/s according to the geostrophic calculation. The newly defined NWCW shows an interannual variation in the range of temperature and occupied area, which is in close relation with the sea surface temperature (SST) over the Yellow Sea and the East China Sea in the previous winter season. The winter SST is determined by winter air temperature, which shows a high correlation with the winter-mean Arctic Oscillation (AO) index. The negative winter-mean AO causes the low winter SST over the Yellow Sea and the East China Sea, resulting in the summertime expansion and lower temperature of the NWCW in the study area. This study shows a dynamic relation among the winter-mean AO index, SST, and NWCW, which helps to predict the movement of NWCW in the northern ECS in summer.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.21-29
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• 2004

Purpose: Much evidence suggests long-term cigarette smoking alters coronary vascular endothelial response. On this study, we applied nonnegative matrix factorization (NMF), an unsupervised learning algorithm, to CO-less $H_2^{15}O-PET$ to investigate coronary endothelial dysfunction caused by smoking noninvasively. Materials and methods: This study enrolled eighteen young male volunteers consisting of 9 smokers $(23.8{\pm}1.1\;yr;\;6.5{\pm}2.5$ pack-years) and 9 nonsmokers $(23.8{\pm}2.9 yr)$. They do not have any cardiovascular risk factor or disease history. Myocardial $H_2^{15}O-PET$ was performed at rest, during cold ($5^{\circ}C$) pressor stimulation and during adenosine infusion. Left ventricular blood pool and myocardium were segmented on dynamic PET data by NMF method. Myocardial blood flow (MBF) was calculated from input and tissue functions by a single compartmental model with correction of partial volume and spillover effects. Results: There were no significant difference in resting MBF between the two groups (Smokers: 1.43 0.41 ml/g/min and non-smokers: $1.37{\pm}0.41$ ml/g/min p=NS). during cold pressor stimulation, MBF in smokers was significantly lower than 4hat in non-smokers ($1.25{\pm}0.34$ ml/g/min vs $1.59{\pm}0.29$ ml/gmin; p=0.019). The difference in the ratio of cold pressor MBF to resting MBF between the two groups was also significant (p=0.024; $90{\pm}24%$ in smokers and $122{\pm}28%$ in non-smokers.). During adenosine infusion, however, hyperemic MBF did not differ significantly between smokers and non-smokers ($5.81{\pm}1.99$ ml/g/min vs $5.11{\pm}1.31$ ml/g/min ; p=NS). Conclusion: in smokers, MBF during cold pressor stimulation was significantly lower compared wi4h nonsmokers, reflecting smoking-Induced endothelial dysfunction. However, there was no significant difference in MBF during adenosine-induced hyperemia between the two groups.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.214-219
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• 1991

To clarify the relationship between ambient water temperature and heading characteristics of rice (Oryza sativa L.), twelve of varieties rice were grown in a cold tolerance screening field where water temperature was controlled by continuous cold water irrigation system to test the cold tolerance of rice. When cold water was continuously irrigated with 5 cm of water depth, the water had stagnated for about three hours, and the water temperature increased gradually from inlet toward outlet in the experimental plot. The fluctuation of water temperature was well synchronized with that of ambient air temperature, and the water temperature near outlet became higher than the air temperature at the vegetative phase, while became lower at the reproductive phase of rice plant community. The leaf development rates on main culm increased by increased water temperature. The rice varities, Fukuhikari, Sangpungbyeo and YR3486-16-2 were more sensitive than the others in the response of leaf development to water temperature. However, Janack and Milyang 42 were comparatively less sensitive to water temperature in leaf development. Janack and Paro -white rices required longer days to develop one leaf on main culm at reproductive phase than at vegetative phase. Varietal difference in days required to develop one leaf on main culm of rice plant was more distinctive at the reproductive phase when water temperature was relatively lower than at the vegetative phase with relatively higher water temperature condition. No difference was found between the growth phases, vegetative and reproductive, in the response of average leaf developmental rates to water temperature under the similar air temperature condition. The estimated average days required to develop one leaf on main culm decreased by 1.3 day by 1$^{\circ}C$ increase in water temperature. Varietal differences in the total number of leaves on main culm depended upon the water temperature, in which the varieties such as Fukuhikari, Gwangmyeon-gbyeo, China 988, and YR3486-16-2 showed increased one leaf by increased water temperature, while Sobaekbyeo, Paro-white, Sangpungbyeo, Pungsanbyeo, Samgangbyeo, and Milyang 42 were kept at the same leaf number regardless of water temperature. However, the total leaf number on main culm and days to heading of Janack increased by increased water temperature. The other varieties showed the shortened days to heading by the increase in water temperature with noticeable varietal differences regardless of the variation in the total number of leaves on main culm.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.2
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• pp.28-41
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• 2023

The objective of the study was to develop an Urban Windway Forest Creation Planning Technique for the Improvement of the Urban Environment using the case of Daejeon Metropolitan City. Through a spatial analysis of fine dust and heat waves, a basin zone, in which the concentration was relatively serious, was derived, and an area with the potential of cold air flow was selected as the target area for the windway forest development by analyzing the climate and winds in the relevant zone. Extreme fine dust areas included the areas of the Daejeon Industrial Complex Regeneration Business District in Daedeok-gu and Daedeok Techno Valley in Yuseong-gu. Heat wave areas included the areas of Daedeok industrial Complex in Moksang-dong, the Daejeon Industrial Complex Regeneration Business District in Daehwa-dong, and the high-density residential area in Ojeong-dong. As a result of measuring the wind speeds in Daejeon with an Automatic Weather System, the average wind speeds during the day and night were 0.1 to 1.7 m/s,, respectively. So, a plan of for a windway forest that smoothly induces the movement of cold air formed in outer forests at night is required. The fine dust/heat wave intensive management zones of Daejeon Metropolitan City were Daejeoncheon, Yudeungcheon, Gapcheon-Yudeungcheon, and Gapcheon. The windway forest formation plan case involved the old city center of Daejeon Metropolitan City among the four zones, the Gapcheon-Yudeungcheon area, in which the windway formation effect was presumed to be high. The Gapcheon-Yudeungcheon area is a downtown area that benefits from the cold and fresh air generated on Mt. Gyejok and Mt. Wuseong, which are outer forests. Accordingly, the windway forest was planned to spread the cold air to the city center by connecting the cold air generated in the Seosa-myeon forest of Mt. Gyejok and the Namsa-myeon forest of Mt. Wuseong through Gapcheon, Yudeungcheon, and street forests. After selecting the target area for the wind ventilation forest, a climate map and wind formation function evaluation map were prepared for the area, the status of variation wind profiles (night), the status of fine dust generation, and the surface temperature distribution status were grasped in detail. The wind ventilation forest planning concept and detailed target sites by type were identified through this. In addition, a detailed action plan was established according to the direction of creation and setting of the direction of creation for each type of wind ventilation forest.

• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.617-622
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• 1998

A cryotherapy system using cold air was developed. The developed system had superior low-temperature characteristics with various flow rates and nozzle sizes, and used R-404A, as a coolant, which has no destructive effects of Ozone layers. Flow rates and the treatment time can be easily altered during the operation. In addition, and alarm system was designed for the overload, overheat, and over-charge of the machine. For clinical applications, skin temperatures, intra-articular temperatures of the knee joint and intra-muscluar temperatures of the gluteal muscles were measured during and after the cryotherapy. After a 5-minute therapy, skin and intra-articular temperatures decreased by $23.3{\pm}4.7 and 4.1 {\pm}1.0^{circ}C$, respectively. A 5-minute cryotherapy was good enough to maintain low intra-articular temperatures for 2-3 hours. Resting intra-muscular temperatures in 2, 4, and 6cm deep in the gluteal muscle were $36.5{\pm}1.2, 36.9{\pm}0.2, 37.1{\pm}0.2^{circ}C$, respectively (p<0.05). Lowest temperatures in 2, 4, and 6cm depth were $35.1{\pm}0.7, 36.2{\pm}0.4, 36.9{\pm}0.3^{circ}C$, respectively (p<0.05). Temperatures after a 2-hour cold air application on the skin and in the muscle in dept도 of 2, 4, and 6cm were $32.2{\pm}1.1, 36.2{\pm}0.5, 36.6{\pm}0.3, 36.9{\pm}0.3^{circ}C$respectively (p<0.05). Temperatures on the skin and in the muscle significantly decreased after 2 hours, compared with before cold air application (p<0.05). The intra-muscular temperature was changed more slowly than the skin temperature, and the deeper the muscle, the lesser temperature changes. The effect of a 5-minute cold air application lasts up to 2 hours, and it seems that the rebound-rise of the temperature dut to the reactive vasodilatation does not occur in the gluteal muscle.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.2
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• pp.165-174
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• 2010

The numerical modeling of a coal gasification reaction occurring in an entrained flow coal gasifier is presented in this study. The purposes of this study are to develop a reliable evaluation method of coal gasifier not only for the basic design but also further system operation optimization using a CFD(Computational Fluid Dynamics) method. The coal gasification reaction consists of a series of reaction processes such as water evaporation, coal devolatilization, heterogeneous char reactions, and coal-off gaseous reaction in two-phase, turbulent and radiation participating media. Both numerical and experimental studies are made for the 1.0 ton/day entrained flow coal gasifier installed in the Korea Institute of Energy Research (KIER). The comprehensive computer program in this study is made basically using commercial CFD program by implementing several subroutines necessary for gasification process, which include Eddy-Breakup model together with the harmonic mean approach for turbulent reaction. Further Lagrangian approach in particle trajectory is adopted with the consideration of turbulent effect caused by the non-linearity of drag force, etc. The program developed is successfully evaluated against experimental data such as profiles of temperature and gaseous species concentration together with the cold gas efficiency. Further intensive investigation has been made in terms of the size distribution of pulverized coal particle, the slurry concentration, and the design parameters of gasifier. These parameters considered in this study are compared and evaluated each other through the calculated syngas production rate and cold gas efficiency, appearing to directly affect gasification performance. Considering the complexity of entrained coal gasification, even if the results of this study looks physically reasonable and consistent in parametric study, more efforts of elaborating modeling together with the systematic evaluation against experimental data are necessary for the development of an reliable design tool using CFD method.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.1
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• pp.27-41
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• 2008

Distribution characteristics of phytoplankton community were investigated by HPLC and flow cytometry in Jeju Strait and the Northern East China Sea (NECS) in May 2004, in order to understand the relationship between physical environmental factors and distribution pattern of phytoplankton communities. Based on temperature and salinity data, three distinct water masses were identified; warm and saline Tsushima Warm Current (TWC), which is flowing from northwest of Jeju Island, warm and low saline water at the center of Jeju Strait, which is originated from China Coastal Water (CCW) and relatively cold and high saline water originated from Yellow Sea at the bottom of the Jeju Strait. At Jeju Strait, less saline water (<33 psu) of 15 km width occupied surface layer up to 20 m which located at 20 km offshore and strong thermal front between warm and saline water and cold and less saline water was found in the middle of the Jeju Strait. Vertical transect of temperature and salinity at the NECS also showed that low saline (<33 psu) water occupied the upper 20 m layer and cold and saline water was present at the eastern part. Chl a was measured as $0.06{\sim}3.07\;{\mu}g/L$. Spring bloom of phytoplankton was recognized by the high concentrations of Chl a at the low saline water masses influenced by the CCW and subsurface chlorophyll maximum layer appeared between $20{\sim}30\;m$ depth, which was at thermocline depth or below. Abundances of Synechococcus and picoeukaryote were $0.2{\sim}9.5{\times}10^4\;cells/mL$ and $0.43{\sim}4.3{\times}10^4\;cells/mL$, respectively. Dinoflagellate, diatom and prymnesiophyte were major groups and minor groups were chlorophyte+prasinophyte, chrysophyte, cryptophyte and cyanophyte. Especially high abundance of dinoflagellate was identified by high concentration (>1\;{\mu}g/L$) of peridinin at the bottom of the thermocline, which showed an outbreak of red tide by high density of dinoflagellates. Abundances of picoeukaryote in Jeju Strait were about $5{\sim}10$ times higher than abundance measured in Kuroshio water and showed a good correlation with Chl b (Pras+Viola), which implies the most of population of picoeukaryote was composed of prasinophytes. Prochlorococcus was not detected at all, which suggests that Kuroshio Current did not directly influenced on the study area. Based on the strong negative correlations between biomass of phytoplankton (Chl a) and temperature+salinity, the primary production and biomass of phytoplankton in the study area were controlled by the nutrients supply from CCW.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.119-124
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• 1997

Using isolated rat heart preparations, we observed the protective effe ts of verapamil cardioplegia on ischemic myocardial injury. Isolated rat hearts were subjected to global ischemia at $25^{\circ}C$ Twenty four isolated Sprague Dawley rat hearts underwent 30 minutes of the retrograde nonworking perfusion with Krebs-Henseleit buffer solution followed by $25^{\circ}C$ cardioplegic solution (St. Thomas'Hospital Cardioplegic Solution) for 60 minutes. Before ischemic arrest, rat hearts were treated with cold cardioplegic solution in control group (n=12) and cold cardioplegic solution with verapamil (1 mg/L) in experimental group (n=12). After 60 minutes of ischemia, hemodynamic and biochemical parameters such as heart rate, left ventricular pressure (LVP), + dp/dt max, coronary flow and creatine phosphokinase (CPK) were measured before giving cardioplegia and 30 minutes after reperfusion. Verapamil group exhibited greater recovery of heart rate, LVP, +dpldt max, coronary flow and CPK than control group (p < 0.05).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.395-399
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• 2017

The LPI fuel filter housings used in automobiles were made from conventional die castings but have recently been developed by cold forging to improve the weight and durability. On the other hand, a sink may develop at the core of the forged product due to the resulting T-shape, which not only reduces the aesthetics, but also increases the post-processing cost of the product. Therefore, this research focused on methods to predict and mitigate sink development and progression during the T-shape forging process. Finite element analysis of the forging process was first performed to determine the optimal initial workpiece devoid of burrs and underfills. An accurate sink prediction was then obtained via metal flow analysis, which was a result of the finite element simulation. Through finite element analysis, it was confirmed that sink development is a product of the differences in nodal velocities arising from the T-shaped forging process. Consequently, a pad was inserted beneath the sink to minimize these velocity differences. The results yielded significant improvement with regard to the sink defect. This method was practically applied to an industrial site to validate the sink improvement.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.29 no.3
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• pp.134-149
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• 2016

Objectives : Gal-Geun-Tang (GT) has been described from SANGHAN in Korean traditional medicine and known to act against cold, fever, hypertension, and nasal catarrh. However, little has yet been learned about the effect of GT on immune function. In the current study, in vitro and in vivo immunomodulatory activity of GT (water extract) was investigated.Methods : Water extract of GT induced in vitro proliferation of spleen cells and significantly increased their proliferative responses during anti-CD3 activation. Using purified splenic T and B cells, it was revealed that GT has a mitogenic activity to B cells and promotes their proliferation induced by lipopolysaccharide, whereas T cell proliferation was not triggered and GT was rather inhibitory to T cell activation caused by anti-CD3 antibody. In the presence of antigen presenting cells (APC), GT addition resulted in a significant increase of IFNγ and IL-4, but not IL-2, production. However, addition of high concentration (1,000㎍/㎖) of GT led to a marked reduction in T cell cytokine production and under such condition, GT facilitated apoptosis of T cells when examined by flow cytometry with propidium iodide staining.Results : In vivo immunomdulation of GT was also investigated using a mouse model. Following keyhole limpet hemocyanin (KLH) immunization, GT (1 ㎎/day) was orally administered for 9 days. Cell numbers in thymus, spleen and peripheral blood were not altered by GT administration, indicating that such dose is not immunotoxic. Cell numbers in draining lymph nodes (LN) and ex vivo Ag-specific proliferation of LN cells were significantly elevated by GT administration. However, any preferential stimulation of T or B and CD4⁺ or CD8⁺ T cell subpopulations was not observed in a flow cytometric analysis of LN cells. This result shows that GT does not promote in vivo B cell proliferation while GT enhances Ag-specific proliferation of LN cells, unlike what was observed in vitro.Conclusions : For a further understanding of in vivo immunomodulatory activity of GT, ex vivo cytokine production of LN cells obtained from KLH-immunized mice was evaluated. Ag-specific IFNγ production was significantly higher in GT-treated mice when compared to PBS-treated control mice. In contrast, IL-4 production in GT-treated group was comparable to control group unlike to in vitro data. In addition, GT administration did not result in any significant differences in serum levels of Ig (IgM, IgG1 and IgG2a) between GT-treated and control groups. Taken together, these data strongly support that GT promotes immune response, more profoundly type 1 helper T cell (Th1) activity and GT may be applicable for treatment of intracellular parasite infection such as viral diseases.