• Journal of The Korean Astronomical Society
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• v.34 no.4
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• pp.317-319
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• 2001

The response of the earth's magnetosphere to the variation of the solar wind parameters and Interplanetary magnetic field (IMF) has been stud}ed by using a high-resolution, three-dimension magnetohydrodynamic (MHD) simulation when the WIND data of velocity Vx, plasma density, dynamic pressure, By and Bz every 1 minute were used as input. Large electrojet and magnetic storm which occurred on October 21 and 22 are reproduced in the simulation (fig. 1). We have studied the energy transfer and tail reconnect ion in association with geomagnetic storms.

• Biomolecules & Therapeutics
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• v.14 no.4
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• pp.226-234
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• 2006

Disturbance of antioxidant system is very common in chronic alcoholics and herbal or natural products with antioxidant activity have been used for its treatment. This study was to investigate the effect of Vitis vinifera extract(V), Schisandra chinensis extract(S), Taraxacum officinale extract(T), Gardenia jasminoides extract(G), Angelica acutiloba extract(A) and Paeonia japonica extract(P), and their combinations on the antioxidant and ethanol oxidation system. Male Sprague-Dawley rats were subjected to Lieber-DeCarli ethanol liquid diet(ED) and were then given different herbal extract mixtures for 6 weeks including VST(V 100+S 150+T 150mg/kg/day), VSG(V 100+S 150+G 150mg/kg/day), VTG(V 100+T 150+G 150mg/kg/day), and VAP(V 100+A 150+P 150mg/kg/day). When the activity of alcohol dehydrogenase(ADH) and acetaldehyde dehydrogenase(ALDH) were compared between ED only group and herbal extracts treatment group, the differences were statistically significant. Phase I and II(glutathione-S-transferase, phenol sulfatransferase) enzyme activities were found to be significantly higher in the VAT treatment group compared to the ED group. Herbal extracts not only repressed the ethanol-induced elevation of malondialdehyde level, but also protected against ethanol-induced decrease in glutathione content, glutathione reductase, glutathione peroxidase, catalase and superoxide dismutase activities. The administration of the herbal extracts was found to be effective in eliminating lipid-peroxides induced by long-term consumption of alcohol by activating various enzyme systems and physiological active compound formation system. After a chronic consumption of alcohol, Angelica Radix protected the liver via activating the ethanol-metabolism enzyme system, and Paeoniae Radix via activating the ethanol-metabolism enzyme and the phase I, II-metabolism enzyme system. Taraxaci Herba was also effective in liver protection via activating the ethanol-metabolism enzyme system and the phase I, II-metabolism enzyme system, Gardeniae Fructus via activating the phase II-metabolism enzyme system and the anti-oxidation system enzyme, and Schisandra Fructus and a grapestone via activating the anti-oxidation system. Our data suggest that these herbal extracts may be useful as a health functional food or new drug candidate for fatty liver and hepatotoxicity induced by chronic alcohol consumption.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.764-768
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• 1998

In connection with the development of new anticonvulsant agents with a broad spectrum, we reported that N-Cbz-alpha-aminoglutarimides, combining common structures of othe r anticonvulsants such as N-CO-C-N and cyclic imides in a single molecule, showed significant anticonvulsant activities in the MES (maximal electroshock seizure) and PTZ (pentylenetetrazole induced seizure) tests. In these studies, a series of (R) and (S) N-alkyloxycarbonyl-alpha-aminoglutarimides 7a-7e and 8a-8e, which were substituted with various alkyloxycarbonyl group instead of Cbz group, were prepared from the corresponding (R) and (S) N-Cbz-glutamic acid 3 and 4, and were evaluated with their anticonvulsant activities against the MES and PTZ tests, including neurotoxicity, in order to define the effect of N-alkyloxycarbonyl group on the anticonvulsant activities of N-alkyloxycarbonyl-${\alpha}$-aminoglutarimides. Among them, (S)N-4-nitrobenzyloxycarbonyl-${\alpha}$-amino-N-methylglutarimide 8e was the most active in MES ($ED_{50}$=35.6mg/kg, PI=2.7) and PTZ tests ($ED_{50}$=15.6, PI=6.1). Interestingly, (R) and (S) N-4-nitrobenzyloxycarbonyl-${\alpha}$-amino-N-methylglutarimide 7e and 8e and (R) N-phenoxycarbonyl-${\alpha}$-amino-N-methylglutrimide 7d showed significant anti-convulsant activities in both the MES and PTZ tests and other compounds showed anticonvulsant activities in only the PTZ test. In addition, it was found that their anticonvulsant activities were dependent on their stereochemistries and N-substituted alkyloxycarbonyl groups.

• Journal of Broadcast Engineering
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• v.9 no.1
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• pp.2-7
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• 2004

In this paper, we proposed the content-based music information retrieval technique using some MPEG-7 low-level descriptors. Especially, pitch information and timbral features can be applied in music genre classification, music retrieval, or QBH(Query By Humming) because these can be modeling the stochasticpattern or timbral information of music signal. In this work, we restricted the music domain as O.S.T of movie or soap opera to apply broadcasting system. That is, the user can retrievalthe information of the unknown music using only an audio clip with a few seconds extracted from video content when background music sound greeted user's ear. We proposed the audio feature set organized by MPEG-7 descriptors and distance function by vector distance or ratio computation. Thus, we observed that the feature set organized by pitch information is superior to timbral spectral feature set and IFCR(Intra-Feature Component Ratio) is better than ED(Euclidean Distance) as a vector distance function. To evaluate music recognition, k-NN is used as a classifier

• Journal of Internet Computing and Services
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• v.8 no.4
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• pp.51-59
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• 2007

This paper presents the development of RFID educational system based on using 900MHz air interface between the reader and the active tag. The software of reader and the active tag is developed on embedded environment, and the software of PC controlling the reader is based on window OS operated as the server. The AT89C51ED2 VLSI chip is used for the processor of the reader and the active tag. As the development environment, Keil compiler is used for the reader and the active tag of which the programing language is C. The visual C language of the visual studio on the PC activated as the server is used for development language. To verify the function of the system, PC gets the tag's identification number through the reader and send the data to with the active tag memory a certain contents as "wite" operation. Finally the data written from the active tag's memory is sent to the PC via the reader as "read" operation and compare the received data with one already sent to the tag.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.11 no.1
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• pp.55-60
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• 1993

Forest occupied a part of natural ecosystem carries out a role of purifying air, preserving water resource, prevention of the breeding and extermination, recreation areas and etc that preserve and for me one's living environment. In this study, the classification for management of this forest is performed with Landsat TM Image. The classes are decided needle-leaf trees, broad-leaf trees, farming land and grass land, and water. When the TM digital images are classified on computer, water is represented in 7∼13 D.N. of 4th band. But the others is appeared similar mostly specific values so that must be done image processing. When the images compounded 2ed band and 3ed band are processed with ratio of enhancement. Needle-leaf treas is represented in l18∼136 D.N. of 1st band, broad-leaf trees in 72∼91 D.N. of 3ed band, farm land and glass land in 96∼120 of 3ed band. Forest Information is classified with M.L.C, an image classification method. The errors of needle-leaf trees, broad-leaf trees, farm land and grass land, and water are appeared each －7.43, ＋1.89,＋7.58 and －2.04 as compared the digital image with investigation on the scene. Finally, these results are useful for classification of forest vegetation with Landsat TM Image.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.202-208
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• 2006

Juice obtained from premature citrus fruits was deacidified by electrodialysis (ED), and its physicochemical and functional properties were evaluated. Total acidities decreased from 3.15 (Aug), 1.62 (Sep), and 1.45% (Oct) to 2.37 (Aug), 0.86 (Sep), and 0.74% (Oct) by electrodialysis for 100 min, respectively, whereas $^{\circ}Brix$ to acid ratio increased, and pH and color remained almost unchanged. Free sugar content of premature citrus juice remained almost unchanged, while organic acid content decreased significantly. Narirutin and hesperidin contents among flavonoids slightly, but not significantly, decreased. $K^+,\;PO_4\;^{2-},\;SO_42^-,\;and\;Cl^-$ contents decreased by ED, with $K^+$ content showing more than 60% decrease, while $Na^+$ content increased 2.5-3.5 times. Total polyphenol content and electron-donating ability decreased slightly by ED, while nitrite-scavenging ability remained almost constant. Sensory evaluation indicated juice (Sep) subjected to ED processing to $12^{\circ}Brix$ with sugar had the highest preference.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.235-244
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• 2019

This study examined the neurotoxicity of aluminum sulfate (AS), an environmental pollutant, and the protective effect of Phrymaleptostachya var. asiatica HARA (PLVAH) extract on the neurotoxicity induced by AS in the cultured C6 glioma cells. For this study, the cell viability and antioxidative effects, such as electron donating (ED) activity, lipid peroxidation (LP) activity, and superoxide anion-radical (SAR) scavenging activity, were analyzed. AS decreased the cell viability significantly in a dose-dependent manner and the $XTT_{50}$ value was measured at $120.0{\mu}M$ of AS. The neurotoxicity of AS was determined to be mid-toxic by Borenfreund and Puerner's toxic criteria. In addition, the catalase (CAT), antioxidant enzyme remarkably increased the cell viability injured by AS-induced neurotoxicity in these cultures. Regarding the protective effect of the PLVAH extract on AS-induced neurotoxicity, PLVAH extract significantly increased the ED ability, and the inhibitory ability of the LP and SAR scavenging ability. These findings suggest that oxidative stress is involved in the cytotoxicity of AS, and the PLVAH extract effectively protected against AS-induced neurotoxicity by its antioxidative effects. Natural resources, such as the PLVAH extract may be a putative therapeutic agent for the treatment of the toxicity induced by heavy metallic compounds, such as AS correlated with the oxidative stress.

• Korean Journal of Radiology
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• v.24 no.3
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• pp.259-270
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• 2023

Objective: It is unknown whether artificial intelligence-based computer-aided detection (AI-CAD) can enhance the accuracy of chest radiograph (CR) interpretation in real-world clinical practice. We aimed to compare the accuracy of CR interpretation assisted by AI-CAD to that of conventional interpretation in patients who presented to the emergency department (ED) with acute respiratory symptoms using a pragmatic randomized controlled trial. Materials and Methods: Patients who underwent CRs for acute respiratory symptoms at the ED of a tertiary referral institution were randomly assigned to intervention group (with assistance from an AI-CAD for CR interpretation) or control group (without AI assistance). Using a commercial AI-CAD system (Lunit INSIGHT CXR, version 2.0.2.0; Lunit Inc.). Other clinical practices were consistent with standard procedures. Sensitivity and false-positive rates of CR interpretation by duty trainee radiologists for identifying acute thoracic diseases were the primary and secondary outcomes, respectively. The reference standards for acute thoracic disease were established based on a review of the patient's medical record at least 30 days after the ED visit. Results: We randomly assigned 3576 participants to either the intervention group (1761 participants; mean age ± standard deviation, 65 ± 17 years; 978 males; acute thoracic disease in 472 participants) or the control group (1815 participants; 64 ± 17 years; 988 males; acute thoracic disease in 491 participants). The sensitivity (67.2% [317/472] in the intervention group vs. 66.0% [324/491] in the control group; odds ratio, 1.02 [95% confidence interval, 0.70-1.49]; P = 0.917) and false-positive rate (19.3% [249/1289] vs. 18.5% [245/1324]; odds ratio, 1.00 [95% confidence interval, 0.79-1.26]; P = 0.985) of CR interpretation by duty radiologists were not associated with the use of AI-CAD. Conclusion: AI-CAD did not improve the sensitivity and false-positive rate of CR interpretation for diagnosing acute thoracic disease in patients with acute respiratory symptoms who presented to the ED.

• Journal of the Korean Society for Heat Treatment
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• v.29 no.2
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• pp.51-55
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• 2016

The P/M processing of titanium aluminide using amorphous TiAl is developed by which it is possible to overcome inherent fabricability problems and to obtain a fine microstructure. A high quality amorphous TiAl powder produced by reaction ball milling shows clear glass transition far below a temperature at the onset of crystallization in differential scanning calorimetry above a heating rate of 0.05 K/s. We obtained a fully dense compact of amorphous TiAl powders, encapsulated in a vacuumed can, via viscous flow by hot isostatic pressing (HIP). Isothermally annealing of HIP'ed amorphous compact under a pressure of 196 MPa shows a progressive growth of ${\gamma}-TiAl$ phase with ${\alpha}2$ ($Ti_3Al$), which is characterized by increasing sharpness of X-ray peaks with temperature. Fully dense HIP'ed compact of titanium aluminide TiAl shows a high hardness of 505 Hv, suggesting strengthening mechanisms by sub-micron sized grain of ${\gamma}-TiAl$ and particle-dispersion by second phase constituent, ${\alpha}2$.