• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.775-776
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• 2005

• Journal of Magnetics
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• v.16 no.2
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• pp.192-195
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• 2011

The phase transition of vortex matter from solid to liquid was studied in iron-based superconductors. Based on the traditional vortex glass theory, we have examined the magnetoresistivity data of iron-based superconductors using our extended thermal activation model: $\rho(B,T)=\rho((T-T_g(B))/(T_c(0)-T_g(B)))^{v(z-1)}$. We predict that the magnetic field-dependent area S + $S_0$ which integrates $\rho$ with T is proportional to $B^{\beta}$, where ${\beta}$ is the vortex glass transition exponent. From our calculation, the vortex glass transition exponent is 0.33, close to the exponent of area $S_0$ + S is 0.31 in $SmO_{0.9}F_{0.1}FeAs$; the exponent of area S is 0.63, which is close to the irreversibility line exponent 2/3. Both of the results show the validity of our model. In addition, our model is shown to be effective in describing irreversibility behavior in layered superconductors.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.53-57
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• 2002

In this paper, we explain new EM(electromagnetic) wave absorber that mixed NC (Natural Ceramics) and Ferrite with NL(Natural Lacquer). At first, a mixed NC and Ferrite(NC : F = (0.1~30)wt% : (99.9~70)wt%) bum at 95$0^{\circ}C$~125$0^{\circ}C$. And then, it is comminuted and injected into NL((NC+F) . NL = (30~80)wt% (70~20)wt%), finally we made Ferrite-NL EM wave absorber. Generally, conventional labor Ferrite covers only 500 MHz to 10 GHz under tolerance limits of 2 to 6 dB in absorption, and Ferrite-NL is over 8 ~ 14 dB. However, NCFerrite-NL huts superior absorption ability. It is over 16 to 19 dB through 500 MHz to 10 GHz.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.11
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• pp.975-978
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• 2003

The microwave dielectric properties and the microstructures on B $i_{0.97}$T $m_{0.03}$Nb $O_4$ doped with $V_2$ $O_{5}$ were systematically investigated. B $i_{0.97}$T $m_{0.03}$Nb $O_4$ ceramics sintered at 920-96$0^{\circ}C$ were mainly consisted of orthorhombic and triclinic phases after addition of $V_2$ $O_{5}$. The apparent density increased slightly with increasing the $V_2$ $O_{5}$ addition. The dielectric constants($\varepsilon$$_{r}$) also increased with $V_2$ $O_{5}$ addition(30-45). The Q${\times}$ $f_{0}$ values measured on B $i_{0.97}$T $m_{0.03}$Nb $O_4$ ceramics doped with $V_2$ $O_{5}$ were between 2,000 and 12,000[GHz] when the sintering temperatures were in the range of 920-960[$^{\circ}C$]. It was confirmed that the temperature coefficient of the resonant frequency($\tau$$_{f}$) can be adjusted from a positive value of +10ppm/$^{\circ}C$ to a negative value of -15ppm/$^{\circ}C$ by increasing the amount of $V_2$ $O_{5}$ Based on our experimental results, the B $i_{0.97}$T $m_{0.03}$Nb $O_4$(added $V_2$ $O_{5}$) ceramics can be applied to multilayer microwave devices at low sintering temperatures.ng temperatures.emperatures.ratures.

• The Korean Journal of Zoology
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• v.13 no.1
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• pp.29-33
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• 1970

The conclusions established in the present study on the chromosomes in vitro of the uterine carcinomas of Korean women are as follows: 1. The pattern of the distribution of chromosome number in uterine carcinoma cells was quite different from that of normal cells, and modal number of the chromosome was 45 and 46. 2. The frequency of diplochromosomes was 0.053 per cell (5.3%) and that of chromosome aberration was 0.16 per cell (16%), which are significantly higher than each of normal cells. In chromosome aberration types, chromatid and isochromatid deletions (chromatid type) and dicentric (chromosome type) were observed. 3. Idiogram analysis showed a tendency that the number of chromosomes belonging to group F increased while that of chromosomes in groups B and E decreased in total. The number of chromosomes in groups C and G in the hypodiploidy cells decreased, but it increased in the hyperdiploidy cells.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.623-624
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• 2006

In this paper, we introduce the design and fabrication of V-band power amplifier MMIC with excellent gain-flatness for IEEE 802.15.3c WPAN system. The V-band power amplifier was designed using ETRI' $0.12{\mu}m$ PHEMT process. The PHEMT shows a peak transconductance ($G_{m,peak}$) of 500 mS/mm, a threshold voltage of -1.2 V, and a drain saturation current of 49 mA for 2 fingers and $100{\mu}m$ total gate width (2f100) at $V_{ds}$=2 V. The RF characteristics of the PHEMT show a cutoff frequency, $f_T$, of 97 GHz, and a maximum oscillation frequency, $f_{max}$, of 166 GHz. The gains of the each stages of the amplifier were modified to have broadband characteristics of input/output matching for first and fourth stages and get more gains of edge regions of operating frequency range for second and third stages in order to make the gain-flatness of the amplifier excellently for wide band. The performances of the fabricated 60 GHz power amplifier MMIC are operating frequency of $56.25{\sim}62.25\;GHz$, bandwidth of 6 GHz, small signal gain ($S_{21}$) of $16.5{\sim}17.2\;dB$, gain flatness of 0.7 dB, an input reflection coefficient ($S_{11}$) of $-16{\sim}-9\;dB$, output reflection coefficient ($S_{22}$) of $-16{\sim}-4\;dB$ and output power ($P_{out}$) of 13 dBm. The chip size of the amplifier MMIC was $3.7{\times}1.4mm^2$.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.555-564
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• 2010

Aphid and mite are the major insects that harm corn. These insects are difficult to control because they are very sensitive to environmental conditions. The purpose of this experiment was to information the loss in quantity of corn and to select inbred lines with resistance after exposing corn to aphid and mite. When exposed to aphid, the average loss in grain yield, ear length, ear diameter, 100 kernel weight, kernel length, kernel width, and kernel thickness were 18.4, 10.9, 1.7, 5.4, 2.3, 1.5 and -0.2%, respectively. When exposed to mite, the average loss in grain yield, ear length, ear diameter, 100 kernel weight, kernel length, kernel width, and kernel thickness were 49.7, 16.5, 20.7, 18.9, 9.5, and -3.4, respectively. Mite had more significant impact on the loss than aphid. Among these factors, grain yield and ear dimater were most significantly correlated on the loss to aphid ($r=0.83^{**}$), while kernel length and thickness were most significantly correlated on the loss to mite ($r=0.83^{**}$). However, ear length was not related to loss to the two insects. The inbred lines that were often used for $F_1$ hybrid which was lower than the average loss by aphid, were KS7, B68, 61B3, 70A1, and KS5, while the inbred lines that were often used for $F_1$ hybrid which was lower than the average decrease by mite, were KS7, B68, 61B3, 66B2-4, 70A1, 72B2, and KS5. These inbred lines could be used to breed inbred lines, hybrid, and open pollination variety that confer resistant to aphid and mite.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.211.1-211.1
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• 2003

There are now increasing evidences that free radicals and reactive oxygen species are involved in a variety of pathological events. Flavonoids. a group of polypenolic compounds, are widespread in the human food supply. This study was carried out to investigate the antioxidant activity of these compounds. myriceitn and (+)-catechin on B 16Fl0. murine melanoma cell line in oxidative stress. Oxidative stress was induced by exposure to hydrogen peroxide. (omitted)

• Journal of Korean Dental Science
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• v.16 no.2
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• pp.164-171
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• 2023

Purpose: To evaluate the antimicrobial persistence of silver diamine fluoride (SDF) and silver fluoride (AgF) on Streptococcus mutans. Materials and Methods: An in vitro experiment was conducted to observe changes in the diameter of the inhibition zone of various materials, including AgF (Riva Star Aqua^TM step 1; SDI), potassium iodine (Riva star aqua^TM step 2; SDI), Fluor protector^® (FP, Ivoclar Vivadent), SDF (Riva star^TM step 1; SDI), Ampicillin (Sigma-Aldrich), Amphotericin B (Nexstar) and negative control on S. mutans. Result: SDF, AgF and FP exhibited significant antimicrobial persistence over the 4 weeks period (P<0.05). At day 28, the diameter of inhibition zone was larger in SDF than in AgF. Conclusion: SDF and AgF have significant antibacterial durability against bacteria commonly associated with dental caries, with the antimicrobial effect lasting for at least 4 weeks. Further clinical studies are needed to validate these findings in vivo.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.9.2-9
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• 1983

We have observed 74 cases of radiolucent foreign bodies in food and air passage in E. N. T. department of Hang Gang Sacred Hospital, from Jan. 1972 to Mar. 1983. The following results were obtained. 1) Distribution of location was 56 cases(75.6 %) in food passage and 18 cases (24.4 %) in air passage. 2) In age distribution, 46 cases (82.1 %) of F. B. in food passage were found in patient over 21 years old and 12 cases (66.7 %) of F. B. in air passage were found in patient under 5 years old. 3) Female seems to be more frequently involved than male in cases of F. B. of food passage and in cases of air passage, male is more frequent. Food passage male: female - - - 25 : 31 Air passage male: female - - - 10 : 8 4) Meats was the most frequent foreign body in food passage (19 cases-33.9%), and the bony pieces was next (17 cases-30.4 %). Plastic material was the most frequent foreign body in air passage (9 cases-49.9 %), and the vegetable seed was the second (4cases-22.0 %). 5) In the location of F. B. in food passage, the first narrowing of the esophagus was the most frequent site and in air passage, the bronchus-especially right bronchus-was the most frequent site. 6) In the duration of lodgement, 44 cases(78.6 %) of F.B. in food passage were visited with - in 24 hours, and 11 cases (61 %) of F. B. in air passage were visited with - in 24 hours. 7) Simple chest PA was checked in all patient and then, esophagogram was checked in 34 cases of F.B. in food passage, among them positive finding was noticed in 23 cases. 8) Removal of F. B. in food passage by esophagoscopy was performed in 54 cases (96.4 %), but in the cases of air passage, removal of F. B. by bronchoscopy was performed in 14 cases (77.8 %). 9) Complications of food passage by the F. B. itself or esophagoscopy were esophageal mucosal laceration (1 cases-1.8 %) and esophageal perforation (1 case -1. 8 %) and complication of air passage by F. B. itself or bronchoscopy were atelectasis (2 cases -11.1 %) and pneumonia (3 cases-16.7 %).