• Advances in Traditional Medicine
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• v.9 no.4
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• pp.277-284
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• 2009

The methanol extract of Dillenia indica was tested for antioxidant activity as determined by free radical scavenging of DPPH radical scavenging assay, reducing power, total antioxidant capacity measured by phosphomolybdenum method, total phenolic content and total flavonoids content determination assays. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant in a dose dependent manner. In DPPH radical scavenging assay the $IC_{50}$ value of the extract was found to be 100.53${\mu}g/ml$ while ascorbic acid has the $IC_{50}$ value 58.92${\mu}g/ml$. Dillenia indica extract showed strong reducing power and total antioxidant capacity. Moreover, methanol extracts also possess high amount of phenolics and flavovonoids and expressed as gallic acid and rutin equivalent respectively. The remarkable activities exhibited in reactive oxygen species scavenging may attributed to the high amount of hydrophilic phenolics present in Dillenia indica.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.758-761
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• 2003

We have designed 5 V/500 mA transless type power module by using semiconductor switching technique, key technique for small size of power supply system. The power module is suitable to a small sized electronic system using a single power supply. It is composed of switching circuit using voltage drop type chopper method, control circuit, voltage detect circuit, and constant voltage circuit, and is fabricated to hybrid-IC type. The switching regulator power supply circuit, designed in this study, has satisfied the electrical characteristics of 5 V/500 mA transless type power module.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.745-748
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• 2003

This paper presents a study on pull cord switch system which is employed in various industry for emergency stop of the equipments. By using power line communication(PLC) technique, in this paper, a new method for operation position detection of pull cord switch is suggested without complicated wiring of separate cables which utilize only 2 lines. Also, using control function of PLC IC, a reset signal for each switch reset can be implemented in the switch status control/sensing device. Finally, this paper shows validity and practical applicability of the proposed operating position sensing system of pull cord switch by implementing the system and revealing the response time and signal through the PLC line.

• Advances in Traditional Medicine
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• v.9 no.3
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• pp.252-258
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• 2009

Shade-dried flowers of Sarcostemma brevistigma Wight Syn (SBF) belonging to Asclepiadaceae yielded a rare flavonol glycoside viz., Quercetin 5a prenyl, 3-O-glucosyl, 7-O-(4c-p-coumaroyl) neohesperidoside which were characterized based on chemical and spectral (including 2D NMR) studies. The ethyl acetate fraction of alcoholic concentrate (test sample) of flowers of this plant (SBF) was evaluated for its hepatoprotective and inhibition of lipid peroxidation activities to investigate the scientific basis of the traditional uses. The oral administration in varying doses viz., 125 and 250 mg/kg of aqueous suspension of SBF to rats for 7 days produced significant (P < 0.01) hepatoprotective effect comparable to that of standard drug silymarin. The SBF afforded good hepatoprotection against $CCl_4$ induced elevation levels of serum marker enzymes, serum bilirubin and liver weight. The free radical scavenging effects of SBF and flavonol glycoside (SA) were assigned by $Fe^{2+}$/ascorbate induction method (in vitro), which revealed the inhibition of lipid peroxidation. The SBF and SA showed prominent anti-lipid peroxidation activity ($IC_{50}$ about $\sim$180 mg/ml and 11.0 mg/ml respectively), which was comparable to standard drug curcumin ($IC_{50}$ about $\sim$8.25 mg/ml). Thus the hepatoprotective activity of SB could be correlated to the free radical scavenging property of the flavonol glycoside.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.7
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• pp.346-352
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• 2006

In Brushless DC Motor, there are Permanent Magnets (PMs) with driving circuit and sensor for detecting to rotor position and rotation speed. In the case of using hall IC sensor which response to magnetic flux, that is required to additional sensor magnet for rotor position detecting. Most of BLDC motor, However, take asymmetrical overhang of PM in rotor instead of additional sensor magnet for operating of hall IC sensor. The asymmetrical overhang of PM occur rotor thrust to z-axis direction that is lead to not only damage of bearing but also intensive noise and vibration. Therefore, the analysis of magnet overhang effect in the side of vibration and drive to hall If sensor is required to precise. In this paper, 2-D Finite Element Method is used to solve precise field computation and thrust of z-axis direction considering asymmetrical magnet overhang. And also the z-axis thrust from the analysis result is compared to experimental result. In conclusion, the purpose of this paper minimize to noise and vibration of BLDC Motor as analyzes to asymmetrical magnet overhang effect.

• Progress in Superconductivity
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• v.8 no.1
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• pp.22-26
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• 2006

Total Fluorine content in the precursor solution for MOD processing of YBCO coated conductors can be significantly reduced by synthesizing precursor solution with F-free Y & Cu precursor and Barium trifluoroacetate(TFA). It was shown that crack-free and uniform precursor films were formed after calcinations in humidified oxygen atmosphere. Less than 2 hours are required to finish the calcination process, and XRD measurement shows that $BaF_2,\;CuO,\;and\;Y_2O_3$ are major constituent of calcined precursor films. Film thickness after calcination was measured to be ${\sim}2.8$ um by applying slot-die coating method. In particular, addition of Samarium shows critical current of Ic=226 A/cm-w($Jc=3.4\;MA/cm^2$). Also discussed are recent developments in the reel-to-reel processing using F-free Y & Cu precursor solutions. It is shown that uniform and fast processing route to YBCO coated conductor with high Ic can be provided by employing F-free Y & Cu precursor solutions in MOD process.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.1
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• pp.59-67
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• 2009

Objectives : This research aimed to evaluate the effects of Rubus coreanus $M_{IQ}$. Methods: These extracts from fresh R. coreanus $M_{IQ}$. were investigated with radical scavenging activity, the content of total phenolics, ferric thiocyanate method and flavonoid contents Results: These results revealed that the ethyl acetate extract from fresh R. coreanus $M_{IQ}$. possesses remarkable radical scavenging activity. The content of total phenolics of the ethanol extract from dried R. coreanus $M_{IQ}$. ($IC_{50}$=155.87${\pm}$8.8${\mu}$g/mL) is the highest among all of the samples. The stronger radical-scavenging activity ($IC_{50}$=77.72${\pm}$2.1${\mu}$g/mL) of ethyl acetate extract from dried R. coreanus $M_{IQ}$. should be related to its phenolic content as measured by gallic acid test. Conclusion: These results suggest that dried R. coreanus $M_{IQ}$. may act as a potential antioxidant agent.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.260-264
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• 2004

The effects of bioactive fractions from Brachyglottis monroi on biological activity were investigated. this bioactive subfraction 6-5 is the most cytotoxic to P388 murine leukaemia cell lines. A comparison of IC/sub 50/ values of these subfraction in cancer cell lines showed that their susceptibility to these subfractions decreased in the following order; Fr. 6-5 > Fr. 6-3 > Fr. 6-6 > Fr. 6-1 > Fr. 6-2 > Fr. 6-4 by the MTT method. Silica gel flash column chromatography concentrated the cytotoxic activity in subfraction 6-5 which eluted with 30% and 40% ethyl acetate : hexane gave a major bioactive (51 mg, P388 IC/sub 50/ 8,286 ng/mL at 7.5 ㎍/disc).

• Archives of Reconstructive Microsurgery
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• v.8 no.2
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• pp.170-175
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• 1999

Objective : Extracranial-intracranial(EC-IC) microvascular anastomosis was performed in 18 patients with hemodynamic cerebral ischemia and traumatic cerebral aneurysm, the aim of this retrospective study was to assess its value in neurosurgical field. Method : Of 18 cases, 17 case were hemodynamic cerebral ischemia and one was traumatic cerebral aneurysm. There were 14 superficial temporal artery(STA)-to-middle cerebral artery(MCA) anastomosis, 3 saphenous vein graft bypass(2 external carotid artery(ECA)-to-MCA, 1main trunk of the STA-to-MCA) and 1 radial artery bypass(ECA-to-MCA). Results : Bypass patency was confirmed by postoperative angiography in all cases except for two cases, postoperative cerebral blood flow of ischemic brain showed significant increased in all cases with good patency through bypass. Conclusion : Revascularization by EC-IC microvascular anastomosis to the ischemic brain eliminated ischemia and was associated with excellent good outcome and good patency rates.

• Journal of the Korean GEO-environmental Society
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• v.21 no.5
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• pp.13-21
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• 2020

In this study, the reliability of the lateral spring constant (k1) applied during design of pile foundation for bridge abutment was evaluated. To do this, the reliability of the factors related to the prediction of the lateral displacement of the abutment pile foundation, which was designed based on the displacement method proposed by Chang (1937), was analyzed. The data used for analysis were the design statements of ◯◯ bridge and ◯◯ IC2 bridge. Then, it was derived by comparing with the numerical analysis (p-y analysis) based on the basic data.