• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.642-650
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• 2010

In this paper, we study a TT&C link to obtain a required specifications of TT&C(Telemetry Tracking and Command system) antenna for an LEO(Low Earth Orbit) satellite. The premised mission orbit is the sun-synchronized and circular orbit and it performs earth-space observations. We design minimum TT&C link-budget to obtain required antenna beamwidth and gain. The proposed turnstile antenna provides wide beamwidth and circular polarization. We suggested the attaching position that shows the most effective results by confirming the variation of antenna performance when the proposed antenna is adapted to satellite's various positions. Also we proved the proposed antenna's ability while it is performing the mission through the orbit simulation based on the electrical performance of the proposed turnstile antenna.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.136-142
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• 2013

CRC features have been added to increase the reliability of the data in memory products for high-speed operation, such as DDR4. High-speed memory products in a shortage of internal timing margin increases for the CRC calculation. Because the existing CRC requires many additional circuit area and delay time. In this paper, we show that the matrix-type CRC and a new XOR/XNOR gate could be improved the circuit area and delay time. Proposed matrix-type CRC can detect all odd-bit errors and can detect even number of bit errors, except for multiples of four bits. In addition, a single error in the error correction can reduce the burden of re-transmission of data between memory products and systems due to CRC errors. In addition, the additional circuit area, compared to existing methods can be improved by 57%. The proposed XOR gate which is consists of six transistors, it can reduce the area overhead of 35% compared to the existing CRC, 50% of the gate delay can be reduced.

• KSBB Journal
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• v.29 no.2
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• pp.124-130
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• 2014

Acer tegmentosum was a traditional Korean herbal medicine showing various pharmacological activities. In this work, A. tegmentosum were extracted with boiling water and then successively partitioned with dichloromethane, ethyl acetate, n-butyl alcohol (n-BuOH), and water. Salidoside, the target compound, was purified in n-BuOH phase using a chromatography method. For the analysis of salidoside, TLC and LC-MS were used as well as on-line screening $HPLC-ABTS^+$ assay with three different wavelength of 254, 280, and 320 nm. An amount of 1.34 g of salidoside were obtained in n-BuOH phase fromAcer tegmentosum was a traditional Korean herbal medicine showing various pharmacological activities. In this work, A. tegmentosum were extracted with boiling water and then successively partitioned with dichloromethane, ethyl acetate, n-butyl alcohol (n-BuOH), and water. Salidoside, the target compound, was purified in n-BuOH phase using a chromatography method. For the analysis of salidoside, TLC and LC-MS were used as well as online screening $HPLC-ABTS^+$ assay with three different wavelength of 254, 280, and 320 nm. An amount of 1.34 g of salidoside were obtained in n-BuOH phase from 3 kg of dry biomass. The on-line screening $HPLC-ABTS^+$ assay is rapid and efficient tool to search bioactivity from A. tegmentosum. 3 kg of dry biomass. The on-line screening $HPLC-ABTS^+$ assay is rapid and efficient tool to search bioactivity from A. tegmentosum.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.47-53
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• 2006

The power losses due to modulation index for multi-modulation scheme were analyzed under various transmission mode of satellite control and the necessary satellite link margin for transmission mode were proposed in this paper On the basis of the analyses for interference between the transmission signals and threshold of satellite control signal receiver, the optimal subcarrier signals were proposed for satellite range measurement methods, respectively. The subcarrier signal of 12 kHz or 14 kHz is proper for telecommand using the ESA method, and 16 kHz for telecommand signal using the GSTDN method. On the other hand, the telemetry subcarrier of 65.536 kHz is a proper in the viewpoint of receiver threshold value.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.12
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• pp.1207-1215
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• 2008

Satellite generates a complex electromagnetic noise by conducted and radiated coupling effect of the various electrical instruments. This noise may cause serious problems on the satellite system. To minimize the electromagnetic coupling effects and maintain the system safety margin, system noise reduction technique should be applied from the beginning of the system design. The COMS system is evaluated by measuring the conducted noise on system electrical power leads at PSR(Power Supply Regulator) and verifying a 6 dB system safety margin under the complex noise environment with current injection. The radiated noise due to the complex transmit antenna configuration is evaluated by integrating all unit-level RE measurement results, and the RF compatibility between spacecraft and launch vehicle is analyzed with the above estimations. This paper describes the COMS EMC compatibility analysis with respect to each unit level EMC test results, and RF compatibility analysis between spacecraft and launch vehicle. The analyzed results will be reflected on FM(Flight Model) EMC test.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.5
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• pp.843-848
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• 2011

In Korea, China, and Japan, Paeonia lactiflora Pall (PL) has been used in the treatment of rheumatoid arthritis, hepatitis, and fever for more than 1200 years. It has been reported that PL has protective effects against $H_2O_2$-induced oxidative stress and LPS-induced liver inflammation. However cellular and molecular mechanism of PL protection against oxidative stress has not fully been elucidated. Here, we describe that the water-soluble extract of PL decreased $H_2O_2$-induced hepatotoxicity. This hepatoprotective effect of PL is reason to decrease the level of intracellular reactive oxygen species (ROS) and increase expression of heme oxygenase 1 (HO-1) and heat shock protein 72 (HSP72) which proteins are involved in protecting the cells from stress like as oxidative stress. We also elucidated that hepatoprotective effect of PL was abolished by knock down of HO-1 and HSP72 by siRNA. These results suggest that the increasing of HO-1 and HSP72 protein by PL treatment might be participated in hepatoprotective effect against oxidative stress such as $H_2O_2$.

• Korean Journal of Pharmacognosy
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• v.41 no.4
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• pp.313-318
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• 2010

Guibi-tang, a traditional herbal medicine, is used for anti-oxidant, anti-osteoporosis, hemostasis and gastroprotection. To develop an analysis method of simultaneous determination of six compounds, swertisin, decursinol, glycyrrhizin, 6-gingerol, costunolide and decursin in Guibi-tang, a high performance liquid chromatography was used with diode array detector. Six bioactive components were separated on a SHISEIDO $C_{18}$ column ($5\;{\mu}m$, 4.6 mm I.D.${\times}$250 mm) with column temperature $30^{\circ}C$. The gradient elution was composed of water with 0.1% trifluoroacetic acid (TFA) and acetonitrile. UV wavelength was set at 230 nm, 254 nm and 330 nm, respectively. Calibration curve showed good linear regression ($R^2$ > 0.9999). The limits of detection (LOD) and the limits of quantification (LOQ) ranged in 0.03 - 0.23 ${\mu}g/ml$ and 0.08 - $0.70\;{\mu}g/ml$, respectively. The RSD values of intra- and inter-day test were in the range of 0.03 ~ 0.96% and 0.01 ~ 1.46%, respectively. The evaluated results of accuracy test were varied from 92.28% ~ 105.14% with RSD < 1.60%. In conclusion, this developed simultaneous determination method was accuracy and sensitive to the quality evaluation of Guibi-tang.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.446-455
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• 2011

Galgeun-tang (GGT) is a traditional medicinal formula that is widely prescribed to treat cold, asthma, and hives in Korea. Fermented herbal medicines can be made more effective than normal herbal medicines by increasing the absorption and bioavailability of the active compounds. In this study, we fermented Galgeun-tang to produce bioconversion constituents using Lactobacillus plantarum (GGT144), and found that four peaks were decreased, three peaks were increased and two new peaks appeared in the HPLC-DAD chromatogram. After HPLC-DAD-guided fractionation of the newly-appearing compounds (1 and 5) and the increased (6, 7, and 9) compounds, the structure of the compounds was determined using NMR and MS. Using this approach the compounds were identified to be pyrogallol (1), daidzein (5), liquiritigenin (6), cinnamyl alcohol (7), and formononetin (9), respectively. In addition, the decreased compounds were identified to be daidzin (2), liquiritin (3), ononin (4), and cinnam aldehyde (8) using HPLC-DAD analysis with standard compounds. The high performance liquid chromatography method was used to quantify the nine constituents in GGT and GGT144. All calibration curves of the standard compounds displayed excellent linearity with a $R^2$ > 0.9968.

• The Journal of Korean Obstetrics and Gynecology
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• v.23 no.4
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• pp.47-56
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• 2010

Purpose: This study was performed to evaluate the single dose oral toxicity of Gwibi-tang extract in ICR mice. Methods: 0(control group), 1250, 2500 and 5000 mg/kg of Gwibi-tang extracts were orally administered to 20 male and 20 female ICR mice. After single oral administration of Gwibi-tang extract to ICR mice, we observed number of the death, clinical signs, changes of body weights for 14 days. After 14 day of Gwibitang extract administration, all mice were sacrificed and major organs were observed. Results: Compared with the control group, we could not find any toxic signs in the mortalities, clinical signs, body weight changes, necropsy findings and hematological values in all treated groups(1250, 2500 and 5000 mg/kg). Conclusions: $LD_{50}$ value of Gwibi-tang extracts may be over 5000 mg/kg and it may have no side toxic effect to ICR mice.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.6
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• pp.9-15
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• 2005

In this research the discharge characteristics of logic gate of the discharge logic gate plasma display panel with the NOT-AND logic function newly designed was analyzed. As for this discharge logic gate a logical output is induced by controlling the voltage between the electrodes using the discharge path. From the experimental result the discharge characteristics of logic gate is influenced by the interrelation of the voltages appling two vertical electrodes. To in the application possibility to large screen PDP, the discharge characteristics by the line resistance of the electrode was evaluated In result it has been inferred that the influence which the drop of voltage by the line resistance of two vertical electrodes exerts on the discharge of the logic gate is minute. Through the experiment, the optimized values of the pulse voltages and the current limitation resistances of each electrode which composed the discharge logic gate were obtained and maximum operation margin of 49[V] was obtained.