• Journal of the Korean Institute of Gas
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• v.25 no.6
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• pp.22-28
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• 2021

Combustion characteristics were examined experimentally for a swirl-stabilized double cone premixed burner nozzle used for industrial gas turbines for power generation. An original model and a variant with a different fuel injection pattern are tested to compare their combustion characteristics such as NOx, CO and stability in pressurized conditions with single burner-flame and in an ambient multi-flame conditions with multi-burners. Test results show that NOx emissions are smaller for the variant, whose number of fuel holes is reduced with the same total area of fuel holes, in ambient and pressurized single-flame conditions with single burner, which results from enhanced fuel/air mixing due to a higher penetration of fuel into the air stream. The multi-burnerflame test results show that NOx emissions are smaller for the variant due to reduced flame interactions, which, on the contrary, slightly reduces the stability margin. On-site test results fromin an actual power plants also show that NOx emissions are reduced for the variant, compared with the original one, which is in agreement with the lab test results stated above.

• Journal of the Korean Geographical Society
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• v.47 no.4
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• pp.606-624
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• 2012

The main objective of this paper is to provide an adequate and comprehensive review of what has been done in South Korea in the field of geospatial analysis and modeling. This review focuses on spatial data analysis and spatial statistics, spatial optimization, and geosimulation among various aspects of the field. It is recognized that geospatial analysis and modeling in South Korea got through the initial stage during the 1990s when computer and analytical cartography and GIS were introduced, moved to the growth stage during the first decade of the $21^{st}$ century when there was a surge of relevant researches, and now is heading for its maturity stage. In spatial data analysis and spatial statistics, various topics have been addressed for spatial point pattern data, areal data, geostatistical data, and spatial interaction data. In spatial optimization, modeling and applications related to facility location problems, districting problems, and routing problems have been mostly researched. Finally, in geosimulation, while most of research has focused on cellular automata, studies on agent-based model and simulation are in beginning stage. Among all these works, some have fostered methodological advances beyond simple applications of the standard techniques.

• Nutrition Research and Practice
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• v.8 no.6
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• pp.618-624
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• 2014

BACKGROUND/OBJECTIVES: Isoflavones are widely believed to be beneficial to human health, in relation to their antioxidant potentials. Exercise can cause an imbalance between reactive oxygen species (ROS) and antioxidants. This study was conducted in order to investigate the ability of isoflavones in amelioration of oxidative stress induced by exercise. MATERIALS/METHODS: Male Sprague-Dawley rats were assigned to one of four groups: isoflavone-free with no exercise (CON-sd), isoflavone-free with exercise (CON-ex), isoflavone-supplemented with no exercise (ISF-sd), and isoflavone-supplemented with exercise (ISF-ex). Animals exercised on the treadmill for 30 minutes per day, five days per week. TBARS as a marker of oxidative stress and antioxidant enzyme activity, including SOD, GSH-px, and catalase were determined in liver tissue. Serum lipid profile was also examined. RESULTS: A significant effect of isoflavone alone was observed on abdominal fat pad mass. ISF-ex had significantly less abdominal fat pad than CON-ex. Both exercise and isoflavone treatment had significant effects on lowering plasma triglyceride (TG), thus, the ISF-ex group had a significantly lower TG level than the CON-sd group, by 30.9%. However, no differences were observed in plasma cholesterol, HDL-C, and cholesterol/HDL-C ratio. Exercise, isoflavone, and exercise-isoflavone interaction effects were significant on thiobarbituric acid reactive substances (TBARS) (P = 0.001, 0.002, and 0.005, respectively). The CON-ex group showed a higher TBARS level than the other three groups. By contrast, in the ISF-ex group, TBARS was restored to the level of the ISF-sd or CON-sd group. Isoflavone had a significant effect on superoxide dismutase (SOD) (P = 0.022) and catalase activities (P = 0.049). Significantly higher SOD and catalase activities were observed in ISF-ex than CON-ex. SOD and catalase activities showed an inverse pattern of TBARS. Taken together, isoflavones increased the activities of SOD and catalase with concomitant decreases in TBARS, indicative of decreased oxidative stress. CONCLUSIONS: Isoflavone supplementation enhances antioxidant action with attenuation of exercise-induced oxidative stress, as measured by decreases in TBARS, and inhibits body fat accumulation and plasma TG increase. Antioxidative effects ascribed to isoflavones may be partially exerted via enhancement of antioxidant enzyme activities.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.563-570
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• 2014

The shortage or surplus of minerals directly affects overall physiological metabolism of plants; especially, it strongly influences carbohydrate metabolism as a primary response. We have studied mineral uptake, synthesis and partitioning of soluble carbohydrates, and the relationship between them in N, P or K-excessive tomato plants, and examined the interaction between soluble carbohydrates and mineral elements. Four-weeks-old tomato plants were grown in a hydroponic growth container adjusted with excessive N ($20.0mmol\;L^{-1}$ $Ca(NO_3)2{\cdot}4H_2O$ and $20.0mmol\;L^{-1}$ $KNO_3$), P ($2.0mmol\;L^{-1}$ $KH_2PO_4$), and K ($20.0mmol\;L^{-1}$ $KNO_3$), respectively, for 30 days. Shoot growth rates were significantly influenced by excessive N or K, but not by excessive P. The concentrations of water soluble N (nitrate and ammonium), P and K were clearly different with each tissue of tomato plants as well as the mineral conditions. The NPK accumulation in all treatments was as follows; fully expanded leaves (48%) > stem (19%) = roots (16%) = petioles (15%) > emerging leaves (1). K-excessive condition extremely contributed to a remarkable increase in the ratio, which ranged from 2.79 to 10.34, and particularly potassium was dominantly accumulated in petioles, stem and roots. Fresh weight-based soluble sugar concentration was the greatest in NPK-sufficient condition ($154.8mg\;g^{-1}$) and followed by K-excessive (141.6), N-excessive (129.2) and P-excessive (127.7); whereas starch was the highest in K-excessive ($167.0mg\;g^{-1}$) and followed by P-excessive (146.1), NPK-sufficient (138.2) and N-excessive (109.7). Soluble sugar showed positive correlation with dry weight-based total N content (p<0.01) whereas was negatively correlated with soluble P (p<0.01) and dry weight-based total P (p<0.01). On the other hand, starch production was negatively influenced by total N (p<0.001), but, it showed positive relation with total K concentration (p<0.05). This study shows that uptake pattern of NPK and production and partitioning of soluble carbohydrate were substantially different from each mineral, and the relationship between water soluble- and dry weight-based-mineral was positive.

• Journal of Korea Technology Innovation Society
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• v.21 no.1
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• pp.64-91
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• 2018

This study explores the interactive pattern among social issue, academic research, and governmental policy on science and technology during the last 20 years. In particular, we try understand wether the science and technology policy research and governmental policy meets social needs appropriately. In order to do this, we have collected text data from news articles, papers, and governmental documents. Based on these data, social network analysis and cluster analysis has been carried out. According to the results, we have found that science and technology policy researches tend to focus on fragmented technological innovation meeting urgent practical needs at the initial stage. However, recently, the main characteristics of science and technology policy research shows co-evolutionary patterns responding to society. Furthermore, time lag also has been observed in the process of interaction among the three bodies. Based on these results, we put forward some suggestions for upcoming researches in science and technology policy. Firstly, analysis levels are needed to be shifted from micro level to mezo or macro level. Secondly, more research efforts are required to be focused on policy process in science technology and its public management. Finally, we have to enhance the sensitiveness to social issues through studies on agenda setting in science and technology policy.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.308-316
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• 2010

Odontoblasts are anchorage dependent cells adhering to a substrate via cell adhesive molecules. Receptor ligands such as integrins bind to these proteins and are known to function as signal transduction molecules in a series of critical recognition events of cell-substratum. The aim of this study is to examine the interaction of odontoblast (MDPC-23 cell) with type I Col and the effect of TGF-${\beta}1$ and TNF-$\alpha$ on the expression of cell adhesion molecules. In this study, MDPC-23 cells adhered to type I Col dose-dependently. Immunofluorescence data demonstrated that integrin ${\alpha}1$, ${\alpha}2$ and CD44 were expressed on cell surface, and FAK and paxillin were localized in focal adhesion plaques in MDPC-23 cells adhesion to Col. Cytokine TGF-${\beta}1$ increased the adhesion of MDPC-23 cells to Col and the expression level of integrin ${\alpha}1$, 4{\alpha}2$ and chondroitin sulfate on MDPC-23 cells. RT-PCR data demonstrated that cytokine TGF-${\beta}1$ increased the amount of integrin ${\alpha}1$ mRNA in MDPC-23 cells. Therefore, MDPC-23 cells adhere to collagen type I Col and expressed a complex pattern of integrins and proteoglycans, including ${\alpha}1$, ${\alpha}2$, chondroitin sulfate and CD44 detected by immunoblotting and immunofluorescence assay. TGF-${\beta}1$ treatment enhanced the expression of adhesion molecules such as integrin ${\alpha}1$, ${\alpha}2$ and chondroitin sulfate.

• Animal Bioscience
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• v.37 no.4
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• pp.709-717
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• 2024

Objective: Abnormally increased somatic cell counts (SCCs) in milk is usually a sign of bovine subclinical mastitis. Mutual interaction between the host and its associated microbiota plays an important role in developing such diseases. The main objective of this study was to explore the difference between cows with elevated SCCs and healthy cattle from the perspective of host-microbe interplay. Methods: A total of 31 milk samples and 23 bovine peripheral blood samples were collected from Holstein dairy cattle to conduct an integrated analysis of transcriptomic and metagenomics. Results: The results showed that Ralstonia and Sphingomonas were enriched in cows with subclinical mastitis. The relative abundance of the two bacteria was positively correlated with the expression level of bovine transcobalamin 1 and uridine phosphorylase 1 encoding gene. Moreover, functional analysis revealed a distinct alternation in some important microbial biological processes. Conclusion: These results reveal the relative abundance of Ralstonia and Sphingomonas other than common mastitis-causing pathogens varied from healthy cows to those with subclinical mastitis and might be associated with elevated SCCs. Potential association was observed between bovine milk microbiota composition and the transcriptional pattern of some genes, thus providing new insights to understand homeostasis of bovine udder.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.4
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• pp.245-249
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• 2007

The alternation of extracellular matrix (ECM) protein in aging process is associated with symptoms such as wrinkling and loss of elasticity in skin. Now, the major target proteins for anti-aging have been metalloproteases and the structural proteins such as collagen and elastin. Recently, the interaction of cell and ECM proteins (collagen, fibrillin, and fibronectin) is reported to have an important role in survival, proliferation and tissue reconstruction. Fibronectin is a matrix adhesion protein which binds to collagen and integrin and degraded by serine proteases. It has been reported that fragments of fibronectin (Fn-fr's) were involved in matrix metalloproteases (MMPs) expression in osteoblast. But, the role of Fn-fr's in human skin and in skin cells has not been reported yet. Therefore, we investigated the differences of fibronectin fragmentation pattern between young and aged human skin, and demonstrated that the fragmentation of fibronectins is significantly increased in aged human skin. Also, treatment of Fn-fr's (70, 45 kDa) increased MMP-1 expression and MMP-2 activity in human dermal fibroblasts. Our results suggest that Fn-fr's as a potential new factor to accelerate skin aging.

• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.757-762
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• 2010

The purposes of this study were to examine the effects of aerobic exercise capacity on free oxygen radicals in blood(FORB) during submaximal exercise in rowing ergometer and as for study purposes, a set of experiments were conducted using one group of 6 rowing players(RP) and the other group of 6 non rowing players(NRP) at the maximum heart rate reserve(HRR) 85~90% exercise intensity. Oxygen free radical was sampled 5 times including a rest period(ARP), immediate after exercise(IAE), 10 minutes after exercise(10MAE), 20 minutes after exercise(20MAE) and 30 minutes after exercise(30MAE). Accordingly, following findings were derived from current study. The effects of interaction between groups and times were significant in oxygen free radical(p<.05) and post hoc tests revealed that significant differences occurred between 10MAE and 20MAE and between 20MAE and 30MAE. In conclusion, the aerobic exercise capacity excellence RP group had more positive recovery pattern than that in the NRP group from FORB of negative influence to the human body

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.251-261
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• 2007

The wind-wave interaction around the Kyung-gi Bay, Korea, was studied using the observed data from ocean buoy at DeuckJeuck-Do from Jan. to Dec., 2005, and from waverider data at KeuckYeulBee-Do on Mar. 19-26 and May 23-28, 2005. Wind-driven surface waves and wave-driven wind speed decrease were estimated from the ocean buoy data, and the characteristics of wave spectrum response were also investigated from the waverider data for the wave developing and calm stages of sea surface, including the time series of spectrum pattern change, frequency trend of the maximum energy level and spectrum slope for the equilibrium state range. The wind speed difference between before and after considering the wave effect was about $2ms^{-1}$ (wind stress ${\sim}0.1Nm^{-2}$) for the wind speed range $5-10ms^{-1}$ and about $3ms^{-1}$ (wind stress ${\sim}0.4Nm^{-2}$) for the wind speed range $10-15ms^{-1}$. Correlation coefficient between wind and wave height was increased from 0.71 to 0.75 after the wave effect considered on the observed wind speed. When surface waves were generated by wind, the initial waves were short waves about 4-5 sec in period and become in gradual longer period waves about 9-10 sec. For the developed wave, the frequency of maximum energy was showed a constant value taking 6-7 hours to reach at the state. The spectrum slope for the equilibrium state range varied with an amplitude in the initial stage of wave developing, however it finally became a constant value 4.11. Linear correlation between the frictional velocity and wave spectrum for each frequency showed a trend of higher correlation coefficient at the frequency of the maximum energy level. In average, the correlation coefficients were 0.80 and 0.82 for the frequencies 0.30 Hz and 0.35 Hz, respectively.