• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.408-416
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• 2002

A 3D hydrodynamic-ecological coupled model was applied to estimate carrying capacity in Geoje-Hansan Bay where is one of the most important oyster culturing grounds in Korea. We considered the carrying capacity as the difference between food supply to the oysters and food demand, considering monthly difference of the actual growth. The food supply to the system was determined from the results of the model simulation (tidal exchange and chlorophyll $\alpha$) over the culturing period from September to May of the following year. The food demand was estimated from the food concentration (chlorophyll $\alpha$) multiple the filtration rate of oysters that is considered monthly different growth rate of oysters and food concentration. The values of carrying capacity for the system varied from 6.1 ton/ha (minimum carrying capacity) in february to 14.91 ton/ha (maximum carrying capacity) in April of marketable size oysters (>4 g wet-tissue weight) depending on temporal variations in the food supply. The oyster production calculated from present facilities was 9 ton/ha in wet-tissue weight in Geoje-Hansan Bay. This value corresponded to $60\%$ of maximum carrying capacity of the system. The optimal carrying capacity without negatively affecting on oyster production was 5.5 ton/ha when calculated from annual statistic data and 6.1 ton/ha when determined by this study. These results suggest that it must be reduced $32\%$~$39\%$ of oyster facilities in the system.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.170-177
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• 2007

In this study, the long-term predictability of El Nino and La Nina events of Pusan National University Coupled General Circulation Model(PNU/CME CGCM) developed from a Research and Development Grant funded by Korea Meteorology Administration(KMA) was examined in terms of the correlation coefficients of the sea surface temperature between the model and observation and skill scores at the tropical Pacific. For the purpose, long-term global climate was hindcasted using PNU/CME CGCM for 12 months starting from April, July, October and January(APR RUN, JUL RUN, OCT RUN and JAN RUN, respectively) of each and every years between 1979 and 2004. Each 12-month hindcast consisted of 5 ensemble members. Relatively high correlation was maintained throughout the 12-month lead hindcasts at the equatorial Pacific for the four RUNs starting at different months. It is found that the predictability of our CGCM in forecasting equatorial SST anomalies is more pronounced within 6-month of lead time, in particular. For the assessment of model capability in predicting El Nino and La Nina, various skill scores such as Hit rates and False Alarm rate are calculated. According to the results, PNU/CME CGCM has a good predictability in forecasting warm and cold events, in spite of relatively poor capability in predicting normal state of equatorial Pacific. The predictability of our CGCM was also compared with those of other CGCMs participating DEMETER project. The comparative analysis also illustrated that our CGCM has reasonable long-term predictability comparable to the DEMETER participating CGCMs. As a conclusion, PNU/CME CGCM can predict El Nino and La Nina events at least 12 months ahead in terms of NIino 3.4 SST anomaly, showing much better predictability within 6-month of leading time.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1907-1914
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• 2013

Textile-type heat exchangers installed on the tunnel walls for facilitating ground source heat pump systems, so called "energy textile", was installed in an abandoned railroad tunnel around Seocheon, South Korea. To evaluate thermal performance of the energy textile, a series of long-term monitoring was performed by artificially applying daily intermittent cooling and heating loads on the energy textile. In the course of the experimental measurement, the inlet and outlet fluid temperatures of the energy textile, pumping rate, temperature distribution in the ground, and air temperature inside the tunnel were continuously measured. From the long-term monitoring, the heat exchange rate was recorded as in the range of 57.6~143.5 W per one unit of the energy textile during heating operation and 362.3~558.4 W per one unit during cooling operation. In addition, the heat exchange rate of energy textile was highly sensitive to a change in air temperature inside the tunnel. The field measurements were verified by a 3D computational fluid dynamics analysis (FLUENT) with the consideration of air temperature variation inside the tunnel. The verified numerical model was used to evaluate parametrically the effect of drainage layer in the energy textile.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.325-330
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• 2005

We are generally interested in the analysis, detection and prediction of structural motifs in proteins, in order to infer compatibility of amino acid sequence to structure in proteins of known three-dimensional structure available in the Protein Data Bank. In this context, we are analyzing some of the well-characterized structural motifs in proteins. We have analyzed simple structural motifs, such as, ${\beta}$-turns and ${\gamma}$-turns by evaluating the statistically significant type-dependent amino acid positional preferences in enlarged representative protein datasets and revised the amino acid preferences. In doing so, we identified a number of ‘unexpected’ isolated ${\beta}$-turns with a proline amino acid residue at the (i+2) position. We extended our study to the identification of multiple turns, continuous turns and to peptides that correspond to the combinations of individual ${\beta}$ and ${\gamma}$-turns in proteins and examined the hydrogen-bond interactions likely to stabilize these peptides. This led us to develop a database of structural motifs in proteins (DSMP) that would primarily allow us to make queries based on the various fields in the database for some well-characterized structural motifs, such as, helices, ${\beta}$-strands, turns, ${\beta}$-hairpins, ${\beta}$-${\alpha}$-${\beta}$, ${\psi}$-loops, ${\beta}$-sheets, disulphide bridges. We have recently implemented this information for all entries in the current PDB in a relational database called ODSMP using Oracle9i that is easy to update and maintain and added few additional structural motifs. We have also developed another relational database corresponding to amino acid sequences and their associated secondary structure for representative proteins in the PDB called PSSARD. This database allows flexible queries to be made on the compatibility of amino acid sequences in the PDB to ‘user-defined’ super-secondary structure conformation and vice-versa. Currently, we have extended this database to include nearly 23,000 protein crystal structures available in the PDB. Further, we have analyzed the ‘structural plasticity’ associated with the ${\beta}$-propeller structural motif We have developed a method to automatically detect ${\beta}$-propellers from the PDB codes. We evaluated the accuracy and consistency of predicting ${\beta}$ and ${\gamma}$-turns in proteins using the residue-coupled model. I will discuss results of our work and describe databases and software applications that have been developed.

• Tunnel and Underground Space
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• v.26 no.2
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• pp.59-67
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• 2016

In this paper, we perform a numerical analysis to evaluate the potential of fault reactivation during gas production from hydrate bearing sediments and the moment magnitude of induced seismicity. For the numerical analysis, sequential coupling of TOUGH+Hydrate and FLAC3D was used and the change in effective stress and consequent geomechanical deformation including fault reactivation was simulated by assuming that Mohr-Coulomb shear resistance criterion is valid. From the test production simulation of 30 days, we showed that pore pressure reduction as well as effective stress change hardly induces the fault reactivation in the vicinity of a production well. We also investigated the influence of stress state conditions to a fault reactivation, and showed that normal fault stress regime, where vertical stress is relatively greater than horizontal, may have the largest potential for the reactivation. We tested one simulation that earthquake can be induced during gas production and calculated the moment magnitude of the seismicity. Our calculation presented that all the magnitudes from the calculation were negative values, which indicates that induced earthquakes can be grouped into micro-seismic and as small as hardly perceived by human beings. However, it should be noted that the current simulation was carried out using the highly simplified geometric model and assumptions such that the further simulations for a scheduled test production and commercial scale production considering complex geometric conditions may produce different results.

• Molecular & Cellular Toxicology
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• v.4 no.1
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• pp.31-44
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• 2008

The forced swim test (FST) is the most widely used model for assessing potential antidepressant activity. Although it has been shown that lateral septum is involved with the FST-related behavior, it is not clear whether antidepressant treatments could alter the FST-induced gene expression profile in the lateral septum. In the present study, the gene expression profiles in response to FST and reboxetine pretreatment were observed in the lateral septum of rats. Reboxetine is known as a most selective serotonin norepinephrine reuptake inhibitor. In addition, we compared the changes in gene expression profile between reboxetine response and nonresponse groups, which were determined by counting FST-related behavior. After FST, lateral septum from controls and reboxetine pretreated group were dissected and gene expression profiles were assessed using an Affymetrix microarray system containing 15,923 genes. Various genes with different functions were changed in reboxetine response group compared with reboxetine nonresponse group, In particular, pleiotrophin, orexin receptor 2, serotonin 2A receptor, neuropeptide Y5 receptor and thyroid hormone receptor $\beta$ were decreased in reboxetine response group, but Lim motif-containing protein kinase 1 (Limk1) and histone deacetylase 1 (HDAC1) were increased. Although further studies are required for direct roles of these genes in reboxetine response, the microarray may provide tools to find out potential target genes and signaling pathways in antidepressant response.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2402-2411
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• 2018

Fluoronitriles-$CO_2$ gas mixtures are promising alternatives to $SF_6$ in environmentally-friendly gas-insulated transmission lines (GILs). Insulating gas heat transfer characteristics are of major significance for the current-carrying capacity design and operational state monitoring of GILs. In this paper, a three-dimensional calculation model was established for a GIL using the thermal-fluid coupled finite element method. The calculated results showed close agreement with experimentally measured data. The temperature distribution of a GIL filled with the Fluoronitriles-$CO_2$ mixture was obtained and compared with those of GILs filled with $CO_2$ and $SF_6$. Furthermore, the effects of the mixture ratio of the component gases and the gas pressure on the temperature rise and current-carrying capacity of the GIL were analyzed. Results indicated that the heat transfer performance of the Fluoronitriles-$CO_2$ gas mixture was better than that of $CO_2$ but worse than that of $SF_6$. When compared with $SF_6$, use of the Fluoronitriles-$CO_2$ gas mixture caused a reduction in the GIL's current-carrying capacity. In addition, increasing the Fluoronitriles gas component ratio or increasing the pressure of the insulating gas mixture could improve the heat dissipation and current-carrying capacity of the GIL. These research results can be used to design environmentally-friendly GILs containing Fluoronitriles-$CO_2$ gas mixtures.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.3
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• pp.189-197
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• 2006

The influence of leodo Ocean Research Station structure to surrounding atmospheric flow is carefully investigated using CFD techniques. Moreover, the validation works of computational results are performed by the comparison with the observed data of leodo Ocean Research station. In this paper, we performed 3-dimensional CAD modelling of the station, generated the grid system for numerical analysis and carried out flow analyses using Navier-Stokes equations coupled with two-equation turbulence model. For suitable free stream conditions of wind speed and direction, the interference of the research station structure on the flow field is predicted. Beside, the computational results are benchmarked by observed data to confirm the accuracy of measured date and reliable data range of each measuring position according to the wind direction. Through the results of this research, now the quantitative evaluation of the error range of interfered gauge data is possible, which is expected to be applied to provide base data of accurate sea surface wind around research stations.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.6
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• pp.550-561
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• 2009

This study is to investigate the air pollution characteristics of an industrialized midsize west-coastal city by comparing air quality to a neighboring inland city. The hourly averaged data of $O_3$, $SO_2$, $NO_2$, CO, and $PM_{10}$ measured from continuous air quality monitoring sites in Gunsan (coastal) and Jeonju (inland) were analyzed. The data set covers the period from 2004 to 2006. The annual average concentrations of the air pollutants in two cities were compared in their abundances and temporal trends as well. $O_3$ and $SO_2$ in Gunsan were relatively higher than those in Jeonju, while vice versa in case of $NO_2$ and $PM_{10}$. It seems that heavy automobile emissions from Jeonju mainly bring on higher $NO_2$ and $PM_{10}$ than those in Gunsan on annual base. $NO_2$ concentrations in both cities showed bimodal diurnal variations with peaks in the morning and in the late evening. These peaks correspond to the coupled effects of rush hour traffic and meteorological conditions (i.e., variation of mixing height and dispersion conditions). Maximum hourly averages of $NO_2$ ranged from 18 ppb to 28 ppb at Jeonju, and from 12 ppb to 20 ppb at Gunsan. $O_3$ showed typical diurnal variation with a maximum in the afternoon between 14:00 and 16:00 LST. Diurnal variations of CO and $PM_{10}$ were similar to $NO_2$ while $SO_2$ was similar to $O_3$. Seasonal variations of $PM_{10}$ in both cities indicated that their concentrations during spring season were significantly high. Asian dust storms occur frequently during spring and seem to affect increase in $PM_{10}$. High $O_3$ and $PM_{10}$ days were selected from both cities. The analyses based on the HYSPLIT trajectory model during the high $O_3$ and $PM_{10}$ showed these episodes (six cases) were mostly coincident with Asian dust storm originated from northern China and Mongolia. However, these high air pollution episodes in the west coastal cities may not only be caused by the Asian dust but also affected by other air pollutants transported from China accompanying the Asian dust.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.1
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• pp.61-66
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• 2011

P2Y receptors are metabotropic G-protein-coupled receptors, which are involved in many important biologic functions in the central nervous system including retina. Subtypes of P2Y receptors in retinal tissue vary according to the species and the cell types. We examined the molecular and pharmacologic profiles of P2Y purinoceptors in retinoblastoma cell, which has not been identified yet. To achieve this goal, we used $Ca^{2+}$ imaging technique and western blot analysis in WERI-Rb-1 cell, a human retinoblastoma cell line. ATP ($10\;{\mu}M$) elicited strong but transient $[Ca^{2+}]_i$ increase in a concentration dependent manner from more than 80% of the WERI-Rb-1 cells (n=46). Orders of potency of P2Y agonists in evoking $[Ca^{2+}]_i$ transients were 2MeS-ATP>ATP>>UTP=${\alpha}{\beta}$-MeATP, which was compatible with the subclass of $P2Y_1$ receptor. The $[Ca^{2+}]_i$ transients evoked by applications of 2MeS-ATP and/or ATP were also profoundly suppressed in the presence of $P2Y_1$ selective blocker (MRS 2179; $30\;{\mu}M$). $P2Y_1$ receptor expression in WERI-Rb-1 cells was also identified by using western blot. Taken together, $P2Y_1$ receptor is mainly expressed in a retinoblastoma cell, which elicits $Ca^{2+}$ release from internal $Ca^{2+}$ storage sites via the phospholipase C-mediated pathway. $P2Y_1$ receptor activation in retinoblastoma cell could be a useful model to investigate the role of purinergic $[Ca^{2+}]_i$ signaling in neural tissue as well as to find a novel therapeutic target to this lethal cancer.