• Korean journal of applied entomology
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• v.30 no.4
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• pp.291-293
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• 1991

Inter-regional difference in median lethal concentration of Bacillus thuringiensis diamondback moth was disclosed to be high. Pyungchang strain showed at most 41 times resistance compared to KN-IA strain of which $LC_{50}$ value was 5.5 ppm. and Oksan strain Showed 11 times resistance. The JMC strain, susceptible to pyrethroids, also showed 12 times resistance against B.T., suggesting difference in resistance mechanism between pyrethroid and B.t.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.338-344
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• 1992

This test has been carried out to clear the effectiveness of pyrethroid insecticides to the Diamond back moth, that was complained by a farmer. The results obtained are summarized as follows. Effectiveness of Pyrethroids to suceptable strain and the results of chemical anaysis on the ingredients of pyrethroikds were normal at recommended concentrations. The effect ualue of pyrethroid by which the blocks were only one time treated was 57-59%, whereas the blocks sprayed 4 consecutive times of pyrethroid didn't show any effectiveness as shown in larval increasing rate of 489-552%. Among the results of field test conducted from 1990 to 1991 at 7 area, Dae Gu area showed the highest Effectiveness as 95-98%. However, Pyong Taek area, showed the least effectiveness as 0% in effect value. The resistant population which was collected at Tae kwan Ryung area was resurrected susceptability as much as JMC, in case of Placing it in non-treatment environment, whereas the pupulation which was revealed to pyrethroids for 6 genetations showed as much as 341-544 times of resistance compared with JMC. The non-effectiveness of pyrethroids to Diamondback moth which was complainted by a certain farmer named Mr Ju, was clearly resulted by the development of insect resistance. In Korea, the resistance of Diamondback moth to pyrethroids has developed in some area, as well as the resistance of pyrethroids has developed according to the continuous use of Insecticides, and the susceptability resurrected by stopping the use of pyrethroids. The result from this test would suggest that the pyrethroid insecticides should be applied in turb with other insecticides.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.102-105
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• 2005

Between 1920 and 1996, a total of 39 Conventions, 29 Recommendations and one Protocol were adopted by the International Labour conference. But Many ILO Instruments were outdated, deficient and not reflective of modern practice, many contained technical detail which discouraged ratification and were thus ineffective. However, many issues which had become relevant were not covered by existing instruments. Therefore, the Governing Body of ILO, at its 262nd Session(March-April 1995), decided to set up a Working Party on Policy regarding the Revision of Standards. It was decided that the Working Party would examine the need for revision of all maritime Conventions and Recommendations adopted before 1985 with a view to rejuvenating and strengthening the standard-setting system. The Working Party initiated its examination of maritime instruments during 273rd Session(November 1998) of the Governing Body. The review made by the Working Party has concluded that of the maritime Conventions examined, seven of them are obsolete and should be revised, 13 should be denounced and six were considered either up to date or were identified for promotion, most of which were approved by the Governing Body. The consolidated maritime labour convention will be adopted in February 2006.

• Korean Journal of Materials Research
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• v.29 no.6
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• pp.363-370
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• 2019

The recent development of information and communication technologies brings new changes to automobile traffic systems. The most typical example is the advancement of dedicated short range communication(DSRC). DSRC mainly consists of an intelligent transportation system(ITS), an electronic toll collection system(ETCS) and an advanced traveler information system(ATIS). These wireless communications often cause unnecessary electromagnetic waves, and these electromagnetic waves, in turn, cause frequent system malfunction. To solve this problem, an absorber of electromagnetic waves is suggested. In this research, various materials, such as powdered metal and iron oxides, are used to test the possibility for an effective absorption of the unnecessary electromagnetic waves. The various metal powders are made into a thin sheet form by compositing through processing. The electromagnetic characteristics(complex permittivity, complex permeability) of the fabricated sheet are measured. As a result, we achieve -6.5 dB at 940 MHz(77.6 % absorption rate) with a 1.0 mm-thickness electromagnet wave absorber, and -9.5 dB at 940 MHz(88.8 % absorption rate) with a 2.0 mm-thickness absorber.

• Korean Journal of Materials Research
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• v.29 no.9
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• pp.532-541
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• 2019

Information and communication technologies are developing rapidly as IC chip size becomes smaller and information processing becomes faster. With this development, digital circuit technology is being widely applied to mobile phones, wireless LANs, mobile terminals, and digital communications, in which high frequency range of GHz is used. In high-density electronic circuits, issues of noise and EMC(Electro-Magnetic Compatibility) arising from cross talk between interconnects or devices should be solved. In this study, sheet-type electromagnetic wave absorbers that cause electromagnetic wave attenuation are fabricated using composites based on soft magnetic metal powder and silicon rubber to solve the problem of electromagnetic waves generated in wireless communication products operating at the frequency range of 2.4 GHz. Sendust(Fe-Si-Al) and carbonyl iron(Fe-C) were used as soft magnetic metals, and their concentrations and sheet thicknesses were varied. Using soft magnetic metal powder, a sheet is fabricated to exhibit maximum electromagnetic attenuation in the target frequency band, and a value of 34.2dB(99.9 % absorption) is achieved at the target frequency.

• Radiation Oncology Journal
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• v.12 no.2
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• pp.129-141
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• 1994

Intracellular ions which have a major role in cellular function have been reported to affect repair of radiation damage. Recently it has been reported that ouabain sensitizes A549 tumor cellls but not CCL-120 normal cells to radiation. Ouabain inhibits the $Na^+-K^+$-pump rapidly thus it increases intracellular Na concentration, Vanadate which is distributed extensively in almost all living organisms is known to be a $Na^+-K^+$-ATPase inhibitors, This study was performed to see any change in radiosensitivity of tumor cell by vanadate and any role of $Na^+-K^+$ATPase in radiosensitization. Experiments have been carried out by pretreatment with vanadate in human cell line(A549, JMG) and mouse cell line(L1210, spleen). For the cell survival MTT assay was performed for A549 and JMC cells and frypan blue dye exclusion test for L120, and spleen cells. Measurements of $Na^+-K^+$-ATPase activity in control, vanadate treated cell, radiation treated cell (9 Gy for A549 and JMG, 2 Gy for L1201, spleen), and combined $10^{-6}M$ vanadate and radiation treated cells were done. The results were summerized as fellows. 1. L1210 cell was most radiosensitive, and spleen cell and JMG cell were intermediate, and A549 cell was least radiosensitive. 2. Mininum or no cytotoxicity was seen with vanadate below concentration of $10^{-6}M$. 3. In A549 cells there was a little change in radiosensitivity with treatment of vanadate. However radiation sensitization was shown in low dose level of radiation i. e. 2- Gy. In JMG cells no change in radiosensitivity was noted. Both L1210 and spleen cell had radiosensitization but change was greater in tumor cell. 4. $Na^+-K^+$-ATPase activity was inhibited significantly in tumor cell by treatment of vanadate. 5. Radiaiton itself inhibited $Na^+-K^+$-ATPase activity of tumor cell with high $Na^+-K^+$-ATPase concention. Increase in radiosensitivity by vanadate was closely associated with orginal $Na^+-K^+$-ATPase contents. From the above results vanadate had little cytotoxicity and it sensitized tumor cells to radiation. Inhibitory effect of vanadate on $Na^+-K^+$-ATPase activity might be one of the contributing factors for radiosensitization to tumor cells which has greater enzyme activity than that of normal cell. It was suggested vanadate could be used as a potential radiosensitizer for tumor cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.839-845
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• 1996

To investigate effects of Jujube methanol extract on the carbon tetrachloride-induced liver damage in rats, experimental animals were divided into 4 groups; control group(CON), Jujube methanol extracttreated group(JME), $CCl_4$- treated groups(CCl), and Jujube methanol extract and $CCl_4$-treated group (JMC). Each group was sacrificed after 2 or 4week feeding and determined the activities of serum transaminase(GOT, GPT) and hepatic xanthine oxidase, superoxide dismutase(SOD), catalase and glutathione peroxidase(GSH-Px), and hepatic contents of thiobarbituric acid-reactants(TBARS) and glutathione in liver. The activities of sGOT and sGPT, and the hepatic content of TBARS after $CCl_4$-treatment were markedly increased, compared to CON, but those levels were significantly decreased by the pretreatment of Jujube methanol extract, especially in sGOT after 2 and 4 week and TBARS after 4week respectively. Xanthine oxidase activity was increased by $CCl_4$- treatment as compared to CON, but it was also inhibited by the pretreatment of Jujube methanol extract for 2 and 4 week. The activities of SOD, catalase and GSH-Px were elevated by $CCl_4$-treatment, compared to CON, but those elevated activities were showed significant decreasing effect by pretreatment of Jujube methanol extract after 2 and 4week as compared to CON, however, hepatic catalase activity was not affected significantly. These results suggest that Jujube methanol extract is believed to be a possible protective effect for the carbon tetrachloride-induced hepatotoxicity in rats.