• Tuberculosis and Respiratory Diseases
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• v.39 no.4
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• pp.325-333
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• 1992

Background and Methods: To study the effects of corticosteroid (CS) on the parquat (PQ) induced lung injury, serial cellular analyses of bronchoalveolar lavage (BAL) fluid were done with simultaneous histopathologic examination after intraperitoneal injection of PQ on the rats. The sacrificed animals were divided into three groups; control group, PQ group received intraperitoneal injection of 20 mg/kg of PQ, and CS group received daily injection of Methylprednisolone sodium succinate (20 mg/kg) in addition to PQ. Results: 1) Cellular analyses of BAL fluid: The total cell count in the BAL fluid were increased gradually from 6 hours after PQ administration (p<0.05), and was decreased at 3 days after (p<0.05). These changes were mainly due to the effects of PQ on the neutrophil influx (p<0.05). But, the number of macrophage and the percentage of lymphocyte in total cells showed little changes. The CS administration showed the suppression of neutrophil influx in the BAL fluid (p<0.05), but could not show any significant effect on the number of macrophage and lymphocyte. 2) Histopathologic examination: In the PQ group, inflammatory changes especially with prominant neutrophil infiltration were gradually progressed over time. Those changes were found in both alveolar space and interstitium with resultant alveolar structural changes, but subsided from 3 days after. CS suppressed inflammatory changes in the alvolar space and interstitium, especially with decreased infiltration of neutrophil. Conclusion: CS suppressed neutrophil infiltration in the acute lung injury induced by PQ, those findings were ascertained by serial cellular analyses of BAL fluid and histopathologic examination.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.443-452
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• 2004

The paper presents an intelligent space management system for ubiquitous computing. The system is basically a home/office automation system that could control light, electronic key, and home appliances such as TV and audio. On top of these basic capabilities, there are four elegant features in the system. First, we can access the system using either a cellular Phone or using a browser on the PC connected to the Internet, so that we control the system at any time and any place. Second, to provide more human-oriented interface, we integrate voice recognition functionalities into the system. Third, the system supports not only reactive services but also proactive services, based on the regularities of user behavior. Finally, by exploiting embedded technologies, the system could be run on the hardware that has less-processing power and storage. We have implemented the system on the embedded board consisting of StrongARM CPU with 205MHz, 32MB SDRAM, 16MB NOR-type flash memory, and Relay box. Under these hardware platforms, software components such as embedded Linux, HTK voice recognition tools, GoAhead Web Server, and GPIO driver are cooperated to support user-friendly intelligent space.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2473-2481
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• 2013

The two characteristics of two-lane-and-two-way traffic flow are platoon and overtaking triggered by low-speed vehicle. It is crucial to develop a robust model which simultaneously generates the behaviors of platoon by low-speed vehicle and overtaking using opposite lane. Hence, a microscopic two-lane and two-way vehicle model was introduced (B. Yoon, 2011), which is based on CA (Cellular Automata) which is one of discrete time-space models, in Korea. While the model very reasonably explains the behaviour of overtaking low-speed vehicle in stable traffic flow below critical density, it has shortcomings to the overtaking process in unstable traffic flow above the critical density. Therefore, the objective of this study is to develope a vehicle model to more realistically explain overtaking process in unstable traffic flow state based on the model developed in the previous study. The experimental results revealed that the car-following model robustly generates the various macroscopic relationships of traffic flow generating stop-and-go traffic flow and the overtaking model reasonably explains the behaviors of overtaking under the conditions of both opposite traffic flow and stochastic parameter to consider overtaking in unstable traffic flow state. The vehicle model presented in this study can be expected to be utilized for the analysis of two-lane-and-two-way traffic flows more realistically than before.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.2 s.314
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• pp.46-54
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• 2007

In current printer industry, four or more colorants are added for color gamut extension because the gamut of printer is smaller than other devices. However, these additional colorants make a redundancy problem that several combinations of colorants reproduced same color stimulus in colorimetric inverse characterization process. Thus, we propose a method of colorimetric inverse characterization using color correlation between colorant's amount. First, for analyzing the combination of colorants which represent the same color stimulus, we estimate the color stimulus for all combination of colorants by Cellular Yule-Nielsen Spectral Neugebauer printer model. The combination of colorants which has higher color correlation factor comparing combinations of colorant around itself in color space is selected. It can reduced the color difference from the tetrahedral interpolation process which is estimation of the output value(colorants combination) for arbitrary input(color stimulus). The selected combinations of colorants and their color stimulus are stored to the lookup table. In experiment, the CMYKGO printer was used. As a result, the dark region of color gamut was extended and the color tone was more naturally represented.

• Journal of the Korea Computer Graphics Society
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• v.24 no.1
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• pp.9-16
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• 2018

In this paper, we introduce a visualization framework for cell image data obtained from optical diffraction tomography (ODT), including a method for representing cell morphology in 3D virtual environment and a color mapping protocol. Unlike commonly known volume data sets, such as CT images of human organ or industrial machinery, that have solid structural information, the cell image data have rather vague information with much morphological variations on the boundaries. Therefore, it is difficult to come up with consistent representation of cell structure for visualization results. To obtain desired visual representation of cellular structures, we propose an interactive visualization technique for the ODT data. In visualization of 3D shape of the cell, we adopt a volume rendering technique which is generally applied to volume data visualization and improve the quality of volume rendering result by using empty space jittering method. Furthermore, we provide a layer-based independent rendering method for multiple transfer functions to represent two or more cellular structures in unified render window. In the experiment, we examined effectiveness of proposed method by visualizing various type of the cell obtained from the microscope which can capture ODT image and fluorescence image together.

• Journal of the Korea Society for Simulation
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• v.22 no.2
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• pp.101-107
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• 2013

Because forest fires are predicted to increase in severity and frequency under global climate change with important environmental implications, an understanding of fire dynamics is critical for mitigation of these negative effects. For the reason, researchers with different background, such as ecologists, physicists, and mathematical biologists, have developed the simulation models to mimic the forest fire spread patterns. In this study, we suggested a novel model considering the wind effect. Our theoretical forest was comprised of two different tree species with varying probabilities of transferring fire that were randomly distributed in space at densities ranging from 0.0 (low) to 1.0 (high). We then studied the distributional patterns of burnt trees using a two-dimensional stochastic cellular automata model with minimized local rules. We investigated the time, T, that the number of burnt trees reaches 25% of the whole trees for different values of the initial tree density, fire transition probability, and the degree of wind strength. Simulation results showed that the values of T decreased with the increase of tree density, and the wind effect decreased in the case of too high or low tree density. We believe that our model can be a useful tool to explore forest fire spreading patterns.

• Journal of the Korean Geographical Society
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• v.52 no.1
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• pp.123-141
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• 2017

This study predicted urban green spaces for 2020 based on two scenarios keeping or freeing the green-belt in the Daegu metropolitan city using a hybrid Cellular Automata(CA)-Markov model and analyzed the spatial dynamics of urban green spaces between 2009 and 2020 using a land cover change detection technique and spatial metrics. Markov chain analysis was employed to derive the transition probability for projecting land cover change into the future for 2020 based on two land cover maps in 1998 and 2009 provided by the Ministry of Environment. Multi-criteria evaluation(MCE) was adopted to develop seven suitability maps which were empirically derived in relation to the six restriction factors underlying the land cover change between the years 1998 and 2009. A hybrid CA-Markov model was then implemented to predict the land cover change over an 11 year period to 2020 based on two scenarios keeping or freeing the green-belt. The projected land cover for 2009 was cross-validated with the actual land cover in 2009 using Kappa statistics. Results show that urban green spaces will be remarkably fragmented in the suburban areas such as Dalseong-gun, Seongseo, Ansim and Chilgok in the year 2020 if the Daegu metropolitan city keeps its urbanization at current pace and in case of keeping the green-belt. In case of freeing the green-belt, urban green spaces will be fragmented on the fringes of the green-belt. It is thus required to monitor urban green spaces systematically considering the spatial change patterns identified by this study for sustainably managing them in the Daegu metropolitan city in the near future.

• Molecules and Cells
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• v.46 no.9
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• pp.545-557
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• 2023

Sphingomyelinase (SMase) catalyzes ceramide production from sphingomyelin. Ceramides are critical in cellular responses such as apoptosis. They enhance mitochondrial outer membrane permeabilization (MOMP) through self-assembly in the mitochondrial outer membrane to form channels that release cytochrome c from intermembrane space (IMS) into the cytosol, triggering caspase-9 activation. However, the SMase involved in MOMP is yet to be identified. Here, we identified a mitochondrial Mg²⁺-independent SMase (mt-iSMase) from rat brain, which was purified 6,130-fold using a Percoll gradient, pulled down with biotinylated sphingomyelin, and subjected to Mono Q anion exchange. A single peak of mt-iSMase activity was eluted at a molecular mass of approximately 65 kDa using Superose 6 gel filtration. The purified enzyme showed optimal activity at pH of 6.5 and was inhibited by dithiothreitol and Mg²⁺, Mn²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Fe²⁺, and Fe³⁺ ions. It was also inhibited by GW4869, which is a non-competitive inhibitor of Mg²⁺-dependent neutral SMase 2 (encoded by SMPD3), that protects against cytochrome c release-mediated cell death. Subfractionation experiments showed that mt-iSMase localizes in the IMS of the mitochondria, implying that mt-iSMase may play a critical role in generating ceramides for MOMP, cytochrome c release, and apoptosis. These data suggest that the purified enzyme in this study is a novel SMase.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1648-1654
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• 2008

Superoxide dismutase (SOD) removes damaging reactive oxygen species from the cellular environment by catalyzing the dismutation of two superoxide radicals to hydrogen peroxide and oxygen. Extracellular superoxide dismutase (EC-SOD) is a tetramer and is present in the extracellular space and to a lesser extent in the extracellular fluids. Increasing therapeutic applications for recombinant human extracellular superoxide dismutase (rEC-SOD) has broadened interest in optimizing methods for its purification, with a native conformation of tetramer. We describe a solid phase refolding procedure that combines immobilized metal affinity chromatography (IMAC) and gel filtration chromatography in the purification of rEC-SOD from Escherichia coli. The purified rEC-SOD tetramer from the $Ni^{2+}$-column chromatography is refolded in Tris buffer. This method yields greater than 90% of the tetramer form. Greater than 99% purity is achieved with further purification over a Superose 12PC 3.2/30 column to obtain the tetramer and specific activities as determined via DCFHDA assay. The improved yield of rEC-SOD in a simple chromatographic purification procedure promises to enhance the development and therapeutic application of this biologically potent molecule.

• Journal of Ginseng Research
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• v.24 no.3
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• pp.138-142
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• 2000

Effects of ginsenosides (Rb$_1$, Rb$_2$, Rc, Re, Rg$_1$, Rf) on L-glutamate (glutamate)-induced swelling of cultured astrocytes from rat brain cerebral cortex were studied. Following the exposure to 0.5mM glutamate for 1 hr, the intracellular water space (as measured by [$^3$H]O-methyl-D-glucose uptake) of astrocytes increased by about two-fold. Simultaneous addition of ginsenosides Rb$_2$ and Rc with glutamate reduced the astrocytic swelling in a dose-dependent manner. These ginsenosides at 0.5 mg/ml did not affect the viability of astrocytes for up to 24 hr which was determined by a colorimetric assay (MTT assay) for cellular growth and survival. These ginsenosides at 0.3 mg/ml inhibited the increase of intracellular Ca$\^$2+/ concentration ([Ca$\^$2+/]$\_$i/) induced by glutamate. These data suggest ginsenosides Rb$_2$ and Rc prevent the cell swelling of astrocytes induced by glutamate, maybe via inhibition of Ca$\^$2+/ influx.