• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.403-409
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• 2013

In this work, a CMOS two stage differential power amplifier which includes Marchand balun, transformer and injection-locked buffer is presented. The power amplifier is targeted for 70 GHz frequency band and fabricated using 65 nm technology. The measurement results show 8.5 dB maximum voltage gain at 71.3 GHz and 7.3 GHz 3 dB bandwidth. The measured maximum output power is 8.2 dBm, input $P_{1dB}$ is -2.8 dBm, output $P_{1dB}$ is 4.6 dBm and maximum power added efficiency is 4.9 %. The power amplifier consumes 102 mW DC power from 1.2 V supply voltage.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.2
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• pp.385-399
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• 1997

The purpose of this experiment was to determine the effects of etching with a Nd : YAG Laser on dentin, or porcelain surface on the bond strength with composite resin. The dentin specimens were devided into the following 4 groups. D1 : No treatment D2 : Etched with 10% phosphoric acid D3 : Laser etchded with 1W, 20PPs D4 : Laser etched with 2W, 20PPS The procelain specimens were devided into the following 4 groups. P1 : diamond roughened P2 : etched with HF acid P3 : Laser etched with 2W, 20PPS P4 : Laser etched with 3W, 20PPS All specimens were veneered with resin. One half of the specimens were stored in $37^{\circ}C$ water for one day and the other half were thermocycled 1000 times at temperature of $5^{\circ}C\;to\;55^{\circ}C$ at 20 seconds intervals. After that, the bonding strength of composite resin to the dentin and porcelain was measured. The surface treated state and fractured state were observed with SEM. The following results were obtained. 1. In the dentin specimens, the bond strength of group D2 was highter than that of groups D1 and D3 in the case of the specimens stored in $37^{\circ}C$ water for one day, there was a statistically significant difference between group D2 and D1, D3 (P<0.05). The bonding strength of the specimens that were thermocycled decreased in the following order : group D2,D4,D3 and then D1. 2. In the porcelain specimens, the bonding strength of groups P1,P2 were higher than that of group P3 in the case of the specimens stored in $37^{\circ}C$ water for one day (P<0.05). The bonding strength of the specimens of being thermocycled decreased in the following order : group P2,P1,P4 and then P3. 3. The groups of high bond strength had a rougher surface and a high level of microporosity with SEM findings.

• Journal of the Korean Chemical Society
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• v.18 no.3
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• pp.157-170
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• 1974

The effects of ionic strength on the polynucleation reaction of tungstate ions and the protonized reaction of polytungstate ions have been investigated in the range of ionic strength from 1 M to 4 M KCl.The hexatungstate ions and the protonized forms of hexatungstate ions are formed in the tungstate solutions whose ionic strengths are 1 M to 4 M KCl. The equilibrium constants for the formation of hexatungstate ions and the protonized forms of hexatungstate ions are calculated in the range of ionic strength from 1 M to 4M KCl. The enthalpy changes for the formation of hexatungstate ions and the protonized forms of hexatungstate ions are as follows; $7H^++{6WO_4}^{2-}={HW_6O_{21}}^{5-}+3H_2O\;\;{\Delta}H^{\circ}=-62.4{\pm}0.6$$H^++{HW_6O_{21}}^{5-}={H_2W_6O_{21}}^{4-}\;\;{\Delta}H+_1^{\circ}=-4.12{\pm}0.10$$H^++{H_2W_6O_{21}}^{4-}={ H_3W_6O_{21}}^{3-}\;\;{\Delta}H_2^{\circ}=-4.36{\pm}0.30$ The free energy and entropy changes for the above reactions have been also calculated. A linear relation is formed between $log k_{6,7}$ and ionic strength, and $log k_1\;or\;log k_2\;vs{\cdot}{\mu}.$ $log k_{6,7}\;=\;D{\mu}+I,\;\;where\;D\;=\;1.66{\pm}0.02$$log k_1\;=\;D_1{\mu}+I_1,\;\;where\;D_1\;=\;-8.065{\pm}0.001$$log k_2\;=\;D_2{\mu}+I_2,\;\;where\;D_2\;=\;-0.376{\pm}0.006$

• Journal of Life Science
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• v.28 no.12
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• pp.1432-1437
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• 2018

Clara cell secretory protein (CCSP) plays an important role in protecting the lungs from inflammation. This research focuses on identifying the cis-element for binding the repressor of CCSP gene expression. A DNase I footprinting experiment revealed three protected regions between -812 and -768 bp (45 bp) of the mCCSP promoter. One motif (D3: GCCTGGGAA) was 100% conserved across rat, hamster, and human. The addition of excess amounts of the D3 motif exhibited high competition within that 45 bp range in an electrophoretic mobility shift assay. However, when mutated D3 ($G{\underline{AA}}TG{\underline{TT}}AA$) was used, the competition was significantly reduced. This demonstrates that the D3 motif within that 45 bp region of the mCCSP promoter is an important site for the protein-DNA interaction. Transient transfection assays with -756 Luc resulted in highly decreased expression of CCSP than those with -812 Luc, suggesting that the 45 bp could function as a binding site for the repressor. Co-transfection of KLF4 exhibited significant repression of the -812 Luc but not the -768 Luc which clearly shows that KLF4 might function as a repressor for the CCSP gene and also suggests that the D3 motif is strongly involved in the binding of KLF4. In addition, when anti-KLF4 antibody was added, super-shifted bands were observed. This result demonstrates that KLF4 could function as a repressor by binding to this 45 bp region of the CCSP promoter and that the D3 motif might be involved in the specific binding of KLF4.

• 한국IT서비스학회:학술대회논문집
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• 2005.11a
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• pp.408-413
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• 2005

D-클래스는 암호학 등의 보안 분야에 응용될 수 있는 가능성을 가지고 있다. 그러나 D-클래스 계산은 NP-완전 문제로서 현재 $4{\times}4$ 이하 크기의 행렬에 대한 D-클래스 만이 알려져 있어 D-클래스의 특성에 대한 연구가 제대로 이루어지지 못하고 있다. 최근 새로운 D-클래스를 얻기 위하여 보다 효율적인 D-클래스 계산에 대한 연구가 수행되었으나 아직 새로운 D-클래스를 계산할 수 있을 정도의 효율적인 연구결과는 보이지 않고 있다. 본 논문은 논리 대수의 연산 특성을 이용하여 D-클래스 계산을 보다 효율적으로 할 수 있는 수학적 이론과 방법을 제시한다.

• Journal of Preventive Medicine and Public Health
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• v.7 no.1
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• pp.177-183
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• 1974

It is generally recognized that the environmental noise of the various working places thought to be the cause of hearing disturbance. This survey was carried out to evaluate the prevalence of noise-induced occupational bearing loss among the weavers of 39 textile industries in Taegu, Korea. For this survey, 432 male workers and 2,023 female workers were examined their hearing acuity by Individual pure tone threshold determination test(air conduction), from November, 1972, to January, 1973. Main findings were as follows : 1. The mean of noise intensity of the 54 weaving rooms was, in over all, $95.6{\pm}4.2dB\;(A),\;95.9{\pm}4.0dB\;(B)\;and\;96.2{\pm}3.9dB\;(C)$. 2. The mean hearing threshold levels by service years in the 4,000 Hz were intensively increased from 1st to 3rd year and slightly decreased. than that of 3rd year, from after 3rd to 5th year, after 5th year that increased slightly. 3. The mean hearing threshold levels by frequencies were highest in the 4,000 Hz(male: $25.0{\pm}11.3dB$, female: $22.0{\pm}10.2dB$) and followed by 6,000, 8,000 and 3,000 Hz. 4. The mean hearing threshold level of the 6,000 Hz (male: 17.0 dB. female: 17.9dB) was higher than that of 4,000Hz (male: 16.4 dB, female: 17.1dB) in tile 1st service year. 5. The mean hearing loss of examinees was $16.2{\pm}8.0dB$ in male and $15.4{\pm}7.8dB$ in female.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.395-398
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• 2002

A chemical investigation of Peucedanum praeruptorum has resulted in the isolation of 3 khellactone derivatives, which have inhibitory effects on melanogenesis in Bl6 mouse melanoma cell lines. The khellactone derivatives were isolated from the crude extract of the roots of Pecedanum praeruptorum by a combination of adsorption chromatography and HPLC. The structlues of isolated compounds were identified as 3',4'- diangeloyl-cis-khellactone, 3'-angeloyl- 4'- senecioyl-cis-khel- lactone and,3', 4'-disenecioyl-cis-khellactone by $^1H\;NMR$, $^{13}C\;NMR$ and mass spectral studies and by comparisons of spectral data with reported literatures.

• Kyungpook Mathematical Journal
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• v.54 no.4
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• pp.577-586
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• 2014

In this paper, we introduce two new types of irresolute functions namely completely D-irresolute functions and weakly D-irresolute functions. We obtain their characterizations and their basic properties.

• Korea Petroleum Association Journal
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• no.7 s.249
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• pp.66-76
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• 2005

●2004년 세계 석유 소비는 8천75만7천 b/d로 전년대비 3.4% 증가하여 1978년 이래 최고상승률을 기록했다. 소비 비중은 미국이 전체의 24.9%를 점유하여 1위를 차지했고 중국(8.2%), 일본(6.4%), 러시아연방(3.4%), 독일(3.3%), 인도(3.2%), 한국(2.8%)순으로 나타났다. ●석유소비증가량은 중국이 전년대비 무려 15.8%인 246만 3천b/d증가하였고 미국은 2.8%인 48만 4천 b/d 증가한 반면 일본은 3.0%인 16만 7천 b/d감소하는 등 전체적으로 246만 7천 b/d증가하였다. ●세계석유생산은 8천 26만 b/d로 전년대비 4.5% 증가하였고 생산량 순으로는 사우디아리비아가 전체의 13.1%를 점유하여 1위를 차지하였고, 러시아연방(11.9%), 미국(8.5%), 이란(5.2%), 멕시코(4.9%), 중국(4.5%) 순으로 나타났다. ●세계석유매장량은 1조 1,886억 배럴로 가채년수는 405년이며 국가별로는 사우디아라비아가 전체의 22.1%를 점유하여 1위를 차지하였고 이란(11.1%), 이라크(9.7%), 쿠웨이트(8.3%), UAE(8.2%), 베네수엘라(6.5%), 러시아연방(6.1%) 순으로 나타났다. ●세계정제능력은 8천 459만 2천b/d로 전년대비 0.8% 증가하였다. 국가별로는 미국이 전체의 20.1%를 점유하여 1위를 차지하였고 중국(6.9%), 러시아연방(6.4%), 일본(5.4%), 한국(3.1%) 순으로 나타났다.

• Journal of Plant Biology
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• v.17 no.4
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• pp.163-170
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• 1974

Leaf tissue of Glycine max Merr. was fixed in para-formaldehyde-glutarldehyde and postfixed in osmium tetroxide or postassium permanganate for electron microscopy. The origin of cytolysome-like organelles of mesophyll cell was studied and changes of fine structure of the organelles according to treating solutions such as gibberellin (GA), kinethin (KI), 2,4-dichlorophenoxy acetic acid(2, 4-D) or 2, 4-D＋GA(1mg/l, respectively) were observed. The cylolysome-like organelles differentiate in endoplasmic reticulum and plasmalemma, and they drop into vacuoles being isolated from the formers. They seem to change into myelin-like structure and to be degenerated by autodigestion. Cytolysome-like organelles involved in cell walls and vacuoles showed activity of acid phosphatase. In the group of GA and KI treatment, cytolysome-like organelles were similar to that of the control group. But in the treatmental groups of 2,4-D and 2,4-D＋GA, myelin-like structures increased in size and autodigestion of this organelles were similar to that of the control group. But in the treatmental groups of 2,4-D and 2,4-D＋GA, myelin-like structures increased in size and autodigestion of this organelle seemed to be accelerated. In the treatmental group of 2,4-D＋GA, myelin-like structures shown high electron density were observed in cytoplasm and vacuoles together.