• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.34-41
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• 2019

Platelet aggregation is essential for the formation of a hemostatic plug in the case of blood vessel damage. On the other hand, excessive platelet aggregation may cause cardiovascular disorders, such as thrombosis, atherosclerosis, and myocardial infarction. Scopoletin, which found in the root of plants in the genus Scopolia or Artemisia, has anti-coagulation and anti-malaria effects. This study examined the effects of scopoletin on human platelet aggregation induced by collagen. Scopoletin had anti-platelet effects via the down-regulation of thromboxane $A_2$ ($TXA_2$) production and intracellular $Ca^{2+}$ mobilization ($[Ca^{2+}]_i$), which are aggregation-inducing molecules produced in activated platelets. On the other hand, scopoletin increased both the cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) levels, which are known as intracellular $Ca^{2+}$-antagonists and aggregation-inhibiting molecules. In particular, scopoletin increased the potently cAMP level more than cGMP, which led to suppressed fibrinogen binding to ${\alpha}IIb/{\beta}_3$ in collagen-induced human platelet aggregation. In addition, scopoletin inhibited collagen-elevated adenosine triphosphate (ATP) release in a dose-dependent manner. The results suggest that aggregation amplification through granule secretion is inhibited by scopoletin. Therefore, scopoletin has potent anti-platelet effects and may have potential for the prevention of platelet-derived vascular diseases.

• Journal of KIISE:Software and Applications
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• v.31 no.8
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• pp.1027-1042
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• 2004

A Software Component is a module that is reused among a lot of projects, systems, and companies rather than a single application. Components can be reused in various systems if they provide not only the common functionalities required in many applications but also the diverse aspects to be customized for being suitable for customers' demands. From the development phase, components should be designed and developed considering the variable aspects they have for convenient customization. Easily customized components can be frequently reused in lots of applications. In the literature, there are some modeling and customizing techniques. But they suggested only conceptual or basic methods based on Object-Oriented. And the practical instructions for reusing component were not provided sufficiently. Moreover, there are few techniques that consider the proper variability types components have. Thus, those techniques are not appropriate for applying to black box component completely developed and released. In this paper, we classify variabilities that components have in functional aspect into two categories. The one is logic variability, and the other is workflow variability. For each classified variability, we propose the three kind of modeling techniques, which are selection, plug in and externalization. Also detailed instructions for practical design and application are provided.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.1
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• pp.37-46
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• 2017

Recently, disaster caused by social factors is frequently occurring in Korea. Prediction about what crisis could happen is difficult, raising the citizen's concern. In this study, we developed a program to acquire tweet data by applying Python language based Tweepy plug-in, regarding social disasters such as 'Nonspecific motive crimes' and 'Oxy' products. These data were used to evaluate psychological trauma and anxiety of citizens through the text clustering analysis and the opinion mining analysis of the R Studio program after natural language processing. In the analysis of the 'Oxy' case, the accident of Sewol ferry, the continual sale of Oxy products of the Oxy had the highest similarity and 'Nonspecific motive crimes', the coping measures of the government against unexpected incidents such as the 'incident' of the screen door, the accident of Sewol ferry and 'Nonspecific motive crime' due to misogyny in Busan, had the highest similarity. In addition, the average index of the Citizens sentiment score in Nonspecific motive crimes was more negative than that in the Oxy case by 11.61%p. Therefore, it is expected that the findings will be utilized to predict the mental health of citizens to prevent future accidents.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.161-163
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• 2002

The BNCT(Boron Neutron Capture Therapy) facility has been developed in Hanaro(High-flux Advanced Neutron Application Reactor), a research reactor of Korea Atomic Energy Research Institute. A typical tangenial beam port is utilized with this BNCT facility. Thermal neutrons can be penetrated within the limits of the possible maximum instead of being filtered fast neutrons and gamma rays as much as possible using the silicon and bismuth single crystals. In addition to, the liquid nitrogen (LN$_2$) is used to cool down the silicon and bismuth single crystals for the increase of the penetrated thermal neutron flux. Neutron beams for BNCT are shielded using the water shutter. The water shutter was designed and manufactured not to interfere with any other subsystem of Hanaro when the BNCT facility is operated. Also, it is replaced with conventional beam port plug in order to cut off helium gas leakage in the beam port. A circular collimator, composed of $\^$6/Li$_2$CO$_3$ and polyethylene compounds, is installed at the irradiation position. The measured neutron flux with 24 MW reactor power using the Au-198 activation analysis method is 8.3${\times}$10$\^$8/ n/cm$^2$ s at the collimator, exit point of neutron beams. Flatness of neutron beams is proven to ${\pm}$ 6.8% at 97 mm collimator. According to the result of acceptance tests of the water shutter, the filling time of water is about 190 seconds and drainage time of it is about 270 seconds. The radiation leakages in the irradiation room are analyzed to near the background level for neutron and 12 mSv/hr in the maximum for gamma by using BF$_3$ proportional counter and GM counter respectively. Therefore, it is verified that the neutron beams from BNCT facility in Hanaro will be enough to utilize for the purpose of clinical and pre-clinical experiment.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.1 s.11
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• pp.11-17
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• 1998

Recently, 3D GIS based on 3D geo-processing methodology and Internet environment are emerging issues in GIS fields. To design and implement 3D GIS, the strategic linkage of Java and VRML is first regarded: 3D feature format definition in the passion of conventional GIS including aspatial attributes, 3B feature indexing, 3D analytical operators such as selection, buffering, and Near, Metric operation such as distance measurement and statistical description, and 3D visualization. In 3D feature format definition, the following aspects are implemented: spatial information for 3D primitives extended from 2D primitives, multimedia data, object texture or color of VRML specification. DXF-format GIS layers with additional attributes are converted to 3D feature format and imported into this system. While, 3D analytical operators are realized in the form of 3D buffering with respect to user-defined point, line, polygon, and 3D objects, and 3D Near functions; furthermore, 'Lantern operator' is newly introduced in this 3D GIS. Because this system is implemented by Java applet, any client with Java-enable browser including VRML browser plug-in can utilize the new style of 3D GIS function in the virtual space. Conclusively, we present prototype of WWW-based 3D GIS, and this approach will be contribute to development of core modules on the stage of concept establishment and of real application model in future.

• Korean Journal of Animal Reproduction
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• v.24 no.3
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• pp.225-230
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• 2000

This study was designed to investigate effect of cryoprotectant kinds and cell stages on the viability of bovine embryos cryopreserved by vitrification. The oocytes were collected from ovarian follicles of Korean native cows. The follicular oocytes were cultured in TCM-199 medium containing hormone and 10%(v/v) FCS for 24~48hrs in a incubator with 5% $CO_2$, in air at 38.5$^{\circ}C$ and then matured oocytes were again cultured for 7~10 hrs with spermatozoa capacitated by preincubation. The vitrification solutions of EFS and EDS were consisted of 40%(v/v) ethylene glycol, 18%(v/v) Ficoll and 0.3M sucrose, and 20%(v/v) ethylene glycol, 16.5%(v/v) DMSO and 0.5M sucrose in TCM-199 medium supplemented with 10% FCS, respectively. The embryos were exposed to EFS or EDS at $25^{\circ}C$ and loaded into OPP straw for 30 sec. The plug end of each straws was heat-sealed and straws was slowly immersed into liquid nitrogen(L$N_2$). The results obtained were summarized as follows : 1 . The rates of cleavage and hatching of embryos frozen with vitrification, rapid and slow freezing methods were 67.5%, 27.5% and 42.5%, 20.0% and 52.5%, 25.0%, respectively And rates of cleavage and hatching of embryos frozen with vitrification method were significantly(p<0.05) higher than those in other methods, and the rates were lower than those in control group(82.5% and 37.5%). 2. The rates of cleavage and hatching of embryos were significantly(p<0.05) different between EFS(47.5% and 22.5%) and EPS(52.5% and 27.5%), and the rates were lower than those in control group(82.5% and 37.5%). 3. After vitrification freezing of bovine embryos at zygote, 2 cell, 8 cell, morulae and blastocyst stage, the rate of cleavage and hatching were 25.0% and 15.0%, 32.5% and 20.0%, 37.5% and 20.0%, 52.5%, 27.5%, 47.5% and 25.0%, respectively. And developmental rates to the expended blastocyst stage of embryos frozen at zygote stage was significantly(p<0.05) lower rather than those in 2, 8-cell and morulae stage.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.156-161
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• 2006

Overhead and sub-irrigation of deep sea water to tomato seedlings reduced the height as 50% and 58% than control plants. In the same treatment with surface sea water and NaCl water, the reduced rate in tomato seedlings' height were 49% and 56% in overhead irrigation, and 47% and 57% in sub-irrigation, respectively. Most effective method for the inhibition of the growth of the seedling was sub-irrigation method, which supplied water through the roots. No significant difference was observed on fresh weight of the upper part of tomato and cucumber seedlings, though the sub-irrigation reduced the fresh weight than the overhead irrigation. The reduced rate of fresh weight of seedlings by overhead irrigation was by 38% and sub-irrigation by 49% as compared to control. Similarly dry weight of upper and under soil parts of seedlings showed same trend of results thereof as fresh weight. This result can be traced to reduction of growth caused by salts in the water. In stem diameter of seedlings no significant difference was observed between two irrigation methods, even though both deep sea and NaCl water reduced stem diameter, as compared to control water. Overhead irrigation can be chosen by seedling producers because of better seedling quality by using TH ratio. Seedling compactness were not noticed in both the overhead and sub-irrigation. Sub-irrigation was found more effective method far the inhibition of height and compactness of tomato seedlings. Higher the concentration of NaCl, deep sea, and surface sea water, lesser the growth in height, fresh and dry weight, stem diameter, and leaf area was obtained. No significant difference was found, though sub-irrigation suppress the growth of seedlings.

• The Journal of the Petrological Society of Korea
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• v.8 no.3
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• pp.171-182
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• 1999

The Myeonbongsan caldera, 10.2X8.0 km, developed within older sequences of sedimentary formations and intermediate composition volcanis in the southern Cheongsong area. Volcanic rocks in the caldera block include lower intermediate volcanics, middle tuffaceous sequences and upper silicic ones. The silicic volcanics, which is named Myeonbongsan Tuff, are composed of crystal-rich ash-flow tuff(300 m) , bedded tuff(30 m) and pumice-rich ash-flow tuff(700 m) in ascending order. Several intrusions dominate the early sequences within the caldera. The caldera collapsed in a trapdoor type when silicic ash-flow tuffs erupted fro major vent area in the caldera. Normal faulting along a ring fault system except the southwestern part dropped the tuffs down to the northrase with a maximum displacement of about 820 m. The Myeonbongsan Tuff is just about 1,030 m thick inside the northeastern caldera, with its base not exposed, and southwestward thinning down. Rhyolitic plug and ring dikes are emplaced along the central vent and the caldera margins, and the ring dikes are cut by plutonic stocks in the southeastern and northwestern parts. The caldera volcanism eviscerated the magma chamber by a series of explosive eruptions during which silicic magma was erupted to form the Myeonbongsan Tuff. Following the last ash-flow eruption, collapse of the chamber roof resulted in the formation of the Myeonbongsan caldera, a subcircular trapdoor-type depression subsiding about 820 m deep. After the collapse, stony to flow-banded rhyolites were emplaced as circular plugs and ring dikes along the central vent and the caldera margins respectively. Finally after the intrusions, another plutons were emplaced as stocks outside the caldera.

• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.38-45
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• 2002

Hydrates are solid cryctallines resembling ice in appearance, which are consist of a gas molecule surrounded by a cage of water molecules. Because of containning a large amount of methane, hydrates have been considered as a future energy resource. However, the formation of hydrates in the oil and gas industries has been known as a serious problem for a long time. The formation of hydrate in pipeline is common in seasonally cold or sub-sea environments with low temperatures and high pressures. Especially, hydrate plug formation becomes a real menace to flow assurance in inadequately protected transmission lines. This study was carried out for the purpose of understanding mechanism of hydrate plugging and examining formation conditions of hydrate in high pressure gas pipeline. In this study, we measured hydrate equilibrium conditions under the various flowing conditions with the methane. The results were presented both the plugging tendency and the effect of flowing velocity.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.71-71
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• 2018

Sea pollution accidents have been occurred due to the increase of marine ship traffic. Oil spill from the hull hole induced by tanker collision results in the huge sea pollution. Proper and prompt reaction on such oil spill disaster is needed to minimize the damage. Thru-hull emergency wood plug is typically used to manually close small holes, while it is required to develop some mechanical devices for closing large holes in the hull due to huge fluid pressure. Accurate estimation of oil discharge and velocity from such holes are important to develop proper device to control hull hole damage. High resolution CFD modeling investigation on the configurations of hull hole of 7.5 m initial depth and 30 cm diameter, which was observed in the oil spill accident of the Hebei Sprit off the west coast of Korea in 2007, has been carried out to compute the oil spill velocity distribution in terms of flow depth. Friction loss due to the viscous flow and the discharge coefficient of crude oil with specific gravity SG = 0.85 and viscosity of $4-12cP(mPa{\cdot}s)$ at the temperature of $20^{\circ}C-100^{\circ}C$ are presented in terms of Reynolds number based on the results of high-resolution CFD modeling.