• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1229-1234
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• 2006

This study investigated whether matrix metalloproteinases (MMPs) can be modified in apoptotic smooth muscle cell (SMC) using the SMC that undergoes apoptotic death by expressing Fas-associated death domain containing protein (FADD) when they are grown without tetracycline in culture medium. In the absence of tetracycline, FADD-SMC lost adherence and showed the fragmentation of the nuclei. In proportion to duration of tetracycline removal, phosphorylated form of p38 MAPK and of ERK increased, whereas phosphorylation of protein kinase B (PKB) was not changed very much in response to tetracycline The levels of cyclin A and cyclin D were also decreased in a time dependent manner. Up-regulation of MMP-9 expression and activity was observed when the SMC were grown without tetracycline. Immunoreactivity of MMP-9 was detected from both attached and floating FADD-SMCs grown without tetracycline. An inhibitor of MAPK kinase, PD098059, and an inhibitor of p38 MAPK, SB203580, inhibited the up-regulation of MMP-9. Treatment of the SMC with a synthetic MMP inhibitor, BB94, attenuated death occurring in the absence of tetracycline. These results indicate that SMC undergoing death is able to up-regulate MMP-9 and that the enzyme can affect cell viability.

• The Korean Journal of Physiology
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• v.11 no.2
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• pp.33-39
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• 1977

It has been reported that administration of Ginseng powder to the Guinea pig reduces anaphylactic shook induced by horse serum (Lee, 1939). However, Lee et al. (1960) and Paik et al. (1976) have demonstrated that Ginseng increases capillary permeabilites and histamine release from the mast cell. These facts suggest that Ginseng acts directly on the bronchial muscle causing it to dilate. Recently, a number of investigators(Kidakawa & Iwasiro 1963; Takagi et al. 1973) have reported that Ginseng reverses acetylcholine- or histamine- induced contraction in the isolated Guinea pig ileum. We, therefore, undertook the present study to examine if Ginseng relaxes the spasm of bronchial muscle induced by acetylcholine or histamine. We have also attempted to identify the mechanism of the Ginseng effect. Male Guinea Pig was sacrificed by a blow on the head, The trachea was removed and sectioned with scissors into about 12 rings. After the 'C' shaped ring of cartilage was sectioned the one end of ring was tied to the bottom of the incubation bath and the other end was connected to a force transducer (FTO 3C) to record tension on a Polygraph. When the antispasmodic action of Ginseng effect was first examined in the normal trachea which was not treated by the drug. And then the Ginseng effect was tested in the muscle treated by histamine hydrochloride, acetylcholine hydrochloride or barium chloride. The results indicate that Ginseng alcohol extract relaxes the contraction of isolated tracheal muscle induced by histamine $(1{\mu}g/ml{\sim}10{\mu}g/ml)$, acetylcholine $(1{\mu}g/ml{\sim}5{\mu}g/ml)$ and barium chloride (1.5 mg/ml). The mechanism of this action is in Pa.1 due to nonspecific antimuscarinic and antihistaminic effect and in part by predominant action in the adrenergic ${\beta}-receptor$ although the ${\alpha}-receptor$ is also involved. We, therefore, conclude that Ginseng can be act as a bronchodilator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11A
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• pp.1872-1879
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• 2001

As multiview video applications become more popular, correspondence problem for stereo image matching plays an important role in expanding view points. Thus, we propose an efficient dense disparity estimation algorithm considering features of each image pair of multiview image sets. Main concepts of the proposed algorithm are based on the region-dividing-bidirectional-pixel-matching method. This algorithm makes matching process efficient and keeps the reliability of the estimated disparities. Other improvement have obtained by proposed cost function, matching window expanding technique, disparity regularization, and disparity assignment in ambiguous region. These techniques make disparities more stable by removing false disparities and ambiguous regions. The estimated disparities are used to synthesize intermediate views of multiview images. Computer simulation demonstrates the excellence of the proposed algorithm in both subjective and objective evaluations. In addition, processing time is reduced as well.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4C
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• pp.424-432
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• 2003

In this paper, an effective method of stereo image reconstruction through the regularized adaptive disparity estimation is proposed. Althougth the conventional adaptive disparity estimation method can sharply improve the PSNR of a reconstructed stereo image, but some problems of overlapping between the matching windows and disallocation of the matching windows can be occurred, because the matching window size changes adaptively in accordance with the magnitude of feature values. Accordingly, in thia paper, a new regularized adaptive disparity estimation technique is proposed. That is, by regularizing the estimated disparity vector with the neughboring disparity vectors, problems of the conventional adaptive disparity estimated scheme might be solved, and also the predicted stereo image can be more effectively reconstructed. From some experiments using the CCETT'S stereo image pairs of 'Man' and 'Claude', it is analyzed that the proposed disparity estimation scheme can improve PSNRs of the reconstructed images to 10.89dB, 6.13dB for 'Man' and 1.41dB, 0.81dB for 'Claude' by comparing with those of the conventional pixel-based and adaptive estimation method, respectively.

• Journal of the Korean Data and Information Science Society
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• v.23 no.4
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• pp.765-775
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• 2012

The cross-validation is a popular method to select bandwidth in all types of kernel estimation. The maximum likelihood cross-validation, the least squares cross-validation and biased cross-validation have been proposed for bandwidth selection in kernel density estimation. In the case that the probability density function has a discontinuity point, Huh (2012) proposed a method of bandwidth selection using the maximum likelihood cross-validation. In this paper, two forms of cross-validation with the one-sided kernel function are proposed for bandwidth selection to estimate the location and jump size of the discontinuity point of density. These methods are motivated by the least squares cross-validation and the biased cross-validation. By simulated examples, the finite sample performances of two proposed methods with the one of Huh (2012) are compared.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.44-48
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• 2007

The cooling heat transfer characteristics of supercritical $CO_2$ in a helical coil gas cooler on the change of coil diameters are experimentally investigated. The main components of the refrigerant loop are a receiver, a variable speed pump, a mass flow-meter, a pre-heater and a helical coil gas cooler (test section). The test sections are made of a copper tube which the inner diameter is 4.55 mm and the helical coil diameters are done of 26.75 mm and 41.35 mm. The mass fluxes of refrigerant are varied from 200 to 800 [$kg/m^2s$] and the inlet pressures of gas cooler are 7.5 to 10.0 (MPa). A gas cooler with helical coil diameter of 26.75 mm has larger heat transfer coefficient than that of 41.35 mm. Also, when compared with experimental data and published correlations avaliable, most of correlations are under-predicted, but Pitla published correlations avaliable, most of correlations are under-predicted, but Pitla et al.'s correlation shows a relatively good coincidence with the experimental data except the region of pseudo critical temperature.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.1-6
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• 2007

The heat transfer coefficient and pressure drop during gas cooling process of $CO_2$ (R-744) in inclined helical coil copper tubes were investigated experimentally. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater and a inclined helical coil type gas cooler (test section). The test section consists of a smooth copper tube, which is specified as the inner diameter of 4.55 mm. The refrigerant mass fluxes were varied from 200 to $600kg/m^2s$ and the inlet pressures of gas cooler were done 7.5 to 10.0 (MPa). The heat transfer coefficients of $CO_2$ in the inclined helical coil tubes increase with the increase of mass flux and gas cooling pressure of $CO_2$. The pressure drop of $CO_2$ in the gas cooler shows relatively good coincidence with those predicted by Ito's correlation developed for single-phase in a helical coil tube. The local heat transfer coefficient of $CO_2$ is well coincident with the correlation by Pitla et al. However, at the region near pseudo-critical temperature, the experiments indicate higher values than the Pitla et al. correlation.

• Journal of the Korean Institute of Gas
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• v.12 no.3
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• pp.43-49
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• 2008

The evaporation heat transfer coefficient and pressure drop of R-22 and R-407C in horizontal copper tubes were investigated experimentally. The main components of therefrigerant loop are a receiver, a compressor, a mass flow meter, a condenser and a double pipe type evaporator (test section). The test section consists of a smooth copper tube of 4.3 mm and 6.4 mm inner diameter. The refrigerant mass fluxes were varied from 100 to $300[kg/m^2s]$ and the saturation temperature of evaporator were 5 [$^{\circ}C$]. The evaporation heat transfer coefficients of R-22 and R-407C rise with the increase in mass flux and vapor quality. The evaporation heat transfer coefficient of R-22 for inner diameter tube of 4.3 mm and 6.4 mm is about $7.3{\sim}47.1%$ and $5.68{\sim}46.6%$ higher than that of R-407C, respectively.

• Journal of Navigation and Port Research
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• v.39 no.4
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• pp.307-312
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• 2015

ARPA(Automatic Radar Plotting Aid) is a device to calculate CPA(closest point of approach)/TCPA(time of CPA), true course and speed of targets by vector operation of relative courses and speeds. The purpose of this study is to develop target acquisition and tracking technology for ARPA Radar implementation. After examining the previous studies, applicable algorithms and technologies were developed to be combined and basic ARPA functions were developed as a result. As for main research contents, the sequential image processing technology such as combination of grayscale conversion, gaussian smoothing, binary image conversion and labeling was deviced to achieve a proper target acquisition, and the NNS(Nearest Neighbor Search) algorithm was appllied to identify which target came from the previous image and finally Kalman Filter was used to calculate true course and speed of targets as an analysis of target behavior. Also all technologies stated above were implemented as a SW program and installed onboard, and verified the basic ARPA functions to be operable in practical use through onboard test.

• The KIPS Transactions:PartB
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• v.11B no.2
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• pp.149-158
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• 2004

This study proposes a method for segmentation and recognition of traffic signs using shape information and edge image in real image. It first segments traffic sign candidate regions by connected component algorithm from binary images, obtained by utilizing the RGB color ratio of each pixel in the image, and then extracts actual traffic signs based on their symmetries on X- and Y-axes. Histogram equalization is performed for unsegmented candidate regions caused by low contrast in the image. In the recognition stage, it utilizes shape information including projection profiles on X- and Y-axes, moment, and the number of crossings and distance which concentric circular patterns and 8-directional rays from region center intersects with edges of traffic signs. It finally performs recognition by measuring similarity with the templates in the database. It will be shown from several experimental results that the system is robust to environmental factors, such as light and weather condition.