• Bulletin of the Korean Chemical Society
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• v.17 no.8
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• pp.760-764
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• 1996

The molecular geometry and vibrational frequencies of 9-fluorenone have been calculated using the Hartree-Fock and Becke-3-Lee-Yang-Parr(B3LYP) density functional methods with 6-31G* basis set. Harmonic vibrational frequencies obtained from the B3LYP calculation show good agreement with the available experimental data. A few vibrational fundamentals are newly assigned based on the B3LYP results. The B3LYP calculation is reconfirmed to be useful in the assignment of the fundamental vibrational frequencies.

• Defense and Technology
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• no.7 s.43
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• pp.25-33
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• 1982

미해병대장비를 위한 AV-8B Harrier 항공기의 최초개발계획이 세인트 루이스에 위치한 McDonnell Douglas 사에서 1981년 10월16일 공식적으로 밝혀졌다. 영국정부가 대형항공익을 보유한 해리어기 대신 AV-8B 해리어기를 선정토록 전년에 결정함으로써 미해병대에 대한 미국계획을 확정토록 하였으며, 1981년 8월24일 미.영간 공식양해각서를 McDonnell Douglas, Pratt & Whitney, British Aerospace 및 Rolls-Royce사간의 체결함으로써 해리어(Harrier)기 이세가 출현하게 되었다.

• Tuberculosis and Respiratory Diseases
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• v.42 no.6
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• pp.862-870
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• 1995

Background: Oxygen free radicals have generally been considered as cytotoxic agents. On the other hand, recent results suggest that small nontoxic amounts of these radicals may act a role in intracellular signal transduction pathway and many efforts to reveal the role of these radicals as secondary messengers have been made. It is evident that the oxygen radicals are released by various cell types in response to extracellular stimuli including LPS, TNF, IL-1 and phorbol esters, all of which translocate the transcription factor $NF{\kappa}B$ from cytoplasm to nucleus by releasing an inhibitory protein subunit, $I{\kappa}B$. Activation of $NF{\kappa}B$ is mimicked by exposure to mild oxidant stress, and inhibited by agents that remove oxygen radicals. It means the cytoplasmic form of the inducible tanscription factor $NF{\kappa}B$ might provide a physiologically important target for oxygen radicals. At the same time, it is well known that LPS induces the release of oxygen radicals in neutrophil with the activation of $NF{\kappa}B$. From above facts, we can assume the expression of IL-8 and IL-$1{\beta}$ gene by LPS stimulation may occur through the activation of $NF{\kappa}B$, which is mediated through the release of $I{\kappa}B$ by increasing amounts of oxygen radicals. But definitive evidence is lacking about the role of oxygen free radicals in the expression of IL-8 and IL-$1{\beta}$ gene in mononuclear phagocytic cells. We conducted a study to determine whether oxygen radicals act a role in the expression of IL-8 and IL-$1{\beta}$ gene in mononuclear phagocytic cells. Method: Human peripheral blood monocytes were isolated from healthy volunteers. Time and dose relationship of $H_2O_2$-induced IL-8 and IL-$1{\beta}$ mRNA expression was observed by Northern blot analysis. To evaluate the role of oxygen radicals in the expression of IL-8 and IL-$1{\beta}$ mRNA by LPS stimulation, pretreatment of various antioxiants including PDTC, TMTU, NAC, ME, Desferrioxamine were done and Northern blot analysis for IL-8 and IL-$1{\beta}$ mRNA was performed. Results: In PBMC, dose and time dependent expression of IL-8 and IL-$1{\beta}$ mRNA by exogenous $H_2O_2$ was not observed. But various antioxidants suppressed the expression of LPS-induced IL-8 and IL-$1{\beta}$ mRNA expression of PBMC and the suppressive activity was most prominant when the pretreatment was done with TMTU. Conclusion: Oxygen free radical may have some role in the expression of IL-8 and IL-$1{\beta}$ mRNA of PBMC but that radical might not be $H_2O_2$.

• Journal of radiological science and technology
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• v.31 no.1
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• pp.71-81
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• 2008

Our objective was to evaluate the image of spatial domain filtering as an alternative to additional image reconstruction using different kernels in MDCT. Derived from thin collimated source images were generated using water phantom and abdomen B10(very smooth), B20(smooth), B30(medium smooth), B40 (medium), B50(medium sharp), B60(sharp), B70(very sharp) and B80(ultra sharp) kernels. MTF and spatial resolution measured with various convolution kernels. Quantitative CT attenuation coefficient and noise measurements provided comparable HU(Hounsfield) units in this respect. CT attenuation coefficient(mean HU) values in the water were values in the water were $1.1{\sim}1.8\;HU$, air($-998{\sim}-1000\;HU$) and noise in the water($5.4{\sim}44.8\;HU$), air($3.6{\sim}31.4\;HU$). In the abdominal fat a CT attenuation coefficient($-2.2{\sim}0.8\;HU$) and noise($10.1{\sim}82.4\;HU$) was measured. In the abdominal was CT attenuation coefficient($53.3{\sim}54.3\;HU$) and noise($10.4{\sim}70.7\;HU$) in the muscle and in the liver parenchyma of CT attenuation coefficient($60.4{\sim}62.2\;HU$) and noise ($7.6{\sim}63.8\;HU$) in the liver parenchyma. Image reconstructed with a convolution kernel led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image scanned with a high convolution kernel(B80) led to an increase in noise, whereas the results for CT attenuation coefficient were comparable. Image medications of image sharpness and noise eliminate the need for reconstruction using different kernels in the future. Adjusting CT various kernels, which should be adjusted to take into account the kernels of the CT undergoing the examination, may control CT images increase the diagnostic accuracy.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.559-562
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• 2002

본 논문에서는 최근 제한적으로 사용이 승인된 UWB(초광대역： Ultra-Wideband) 통신을 AWGN 하에서 다중 접속을 고려하지 않은 단일 사용사일 경우로 가정시, M진 값이 변화함에 따른 에러율과 성능 개선 기법으로 BCH를 채용시의 에러율을 비교 분석하였다. 기존에 연구되어 오던 변조로 PAM(Pulse Amplitude Modulation)과 PPM(Pulse Position Modulation)방식을 비교하였으며 에러율 $10^{-6}$을 기준으로 M=2, 4일 경우 PAM이 PPM보다 약 E$_{b}$/N$_{o}$ =3~4［dB］, M=8 이상의 경우 PPM이 약 E$_{b}$/N$_{o}$ =9［dB］, M=16일 경우 약 E$_{b}$/N$_{o}$ =15［dB］정도 성능이 우수하였다. AWGN 채널 하에서 에러 정정 부호인 BCH(15,7)를 도입하였을 경우 에러율 $10^{-6}$을 기준으로 PAM방식은 약 E$_{b}$/N$_{o}$ 가 약 1［dB］, PPM 방식은 M=2, 4일 경우 약 E$_{b}$/N$_{o}$ =1~1.5［dB］정도 개선되었다.

• Journal of Nutrition and Health
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• v.29 no.8
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• pp.881-888
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• 1996

The purpose of this study was to determine whether vitamin B6(B6) deficiency affects fuel utilization and blood cholesterol profile with exercise-training. Twenty-four rats were fed a B6 deficient(-B6) diet or a control (+B6) diet for 5 weeks and either exercised(EX) or nonexercised (NE). EX rats were exercised on treadmill(10$^{\circ}$, 0.5-0.8km/h) for 20 minutes everyday. Glucose(GLU), glycogen (GLY), protein(PRO), trglyceride(TG), free fatty acid(FFA), total cholesterl(TC), HDL-cholesterol(HDL-C) and LDL-choleterol(LDL-C) were compared in plasma(P), liver(L) and skeletal muscle(M) of rats. There was a vitamin effect on the level of P-GLU, P-TG, M-TG, L-GLY, L-PRO and an exercise effect on the level of P-PRO, P-FFA, M-PRO, L-GLY, L-TG, P-TC, P-HDL-C, P-LDL-C. Compared to +B6 rats were lower and there were no differences in P-GLU, P-FFA, P-TG. M-GLY, L-TG, P-TC and P-HDL-C. In EX group, the level of P-TG was higher and M-PRO was lower in -B6 rats. There were no differences in M-GLY, L-TG, P-TC and P-HDL-C. These results suggest that a lowered intake of vitamin B6 may impair the adaptation of animals to fuel metabolism related to a decrease of fatty acid oxidation and attenuates the exercise-traning effect on blood lipid profile.

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.318-323
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• 1997

ο-(2-Vinyloxyethoxy)benzylidenemalononitrile (3a) and methyl ο-(2-vinyloxyethoxy)-benzylidenecyanoacetate (3b), m-(2-vinyloxyethoxy)benzylidenemalononitrile (4a), and methyl m-(2-vinyloxyethoxy)benzylidenecyanoacetate (4b) were prepared by the condensation of ο-(2-vinyloxyethoxy)benzaldehyde (1) and m-(2-vinyloxyethoxy)benzaldehyde (2) with malononitrile or methyl cyanoacetate, respectively. Bifunctional vinyl ether monomers 3a and 3b polymerized quantitatively with radical initiators in γ-butyrolactone solution at 65 ℃, while meta-isomers 4a and 4b gave lower yields of polymers under the same conditions. The polymers 5-6 obtained from the monomers 3-4 were insoluble in common solvents due to cross-linking. Under the same polymerization conditions ethyl vinyl ether polymerized well with model compounds ο-methoxybenzylidenemalononitrile 7a, methyl ο-methoxybenzylidenecyanoacetate 7b, m-methoxybenzylidenemalononitrile 8a, and methyl m-methoxybenzylidenecyanoacetate 8b, respectively, to give 1:1 alternating copolymers 9-10 in high yields. Cross-linked polymers 5-6 showed a thermal stability up to 300 ℃, and showed a double phase degradation pattern in their TGA thermograms. Polymers 5-6 showed broad endothermic bands around 75-110 ℃ without any characteristic Tg peaks in DSC thermograms. Alternating copolymers 9-10, except copolymer 9b were soluble in common organic solvents. The inherent viscosities of polymer 9-10 were in the range of 0.35-0.62 dL/g. Polymer films cast from acetone solution were cloudy and tough and Tg values obtained from DSC thermograms were in the range of 118-165 ℃.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.6
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• pp.63-70
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• 2012

This paper discussed on the directive gain improvement method of the U-type ultra wide-band(UWB) planar patch antenna model with CPW feeding. For directive gain improvement, the U-type printed patch antenna model with CPW feeding is reconstructed as a microstrip structure by adding a reflection plane with aperture slot. The reflection coefficient of the reconstructed antenna is less than -6.5 dB(VSWR < 3.3) to the characteristic impedance of $50.08{\Omega}$ and showed the directive radiation patterns with the directive gain of 7.5 dBi ~ 10.1 dBi, the front-back ratio of 17.8 dB ~ 28.7 dB and the range of -3dB radiation angle over ${\pm}30^{\circ}$ to the main beam direction of ${\theta}=0^{\circ}$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.4
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• pp.345-351
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• 2022

In this study, the target strength for multi-frequency (38 kHz, 120 kHz, 200 kHz) of juvenile silverfish (Pleuragramma antarcticum) was estimated using by the KRM (Kirchhoff-ray mode) model. The body shape of the silverfish was described by a picture and the body length of nine individuals ranged in 1.8 cm to 8.8 cm. The maximum TS_cm according to the total length for the constant term (b20) was -92.93 dB at 38 kHz, -86.63 dB at 120 kHz, and -85.89 dB at 200 kHz, respectively. The averaged TS_cm according to total length for the constant term (b20) was -100.0 dB at 38 kHz, -93.0 dB at 120 kHz, and -106.9 dB at 200 kHz, respectively.

• Journal of Magnetics
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• v.8 no.2
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• pp.93-97
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• 2003

For the induction motor and inverter type motor design, prediction and analysis of core loss including higher harmonics have been studied. In this work, we have generated two symmetrical ac minor loop in the fundamental hysteresis loop whose positions are zero induction region and saturation induction region, and we could pre-dict core loss including higher harmonics inductions. using the following modified superposition principle; $P_c(B_0,f_0,B_h,nf_0)=P_c(B_0,f_0)+(n-1)[K_1(B_0)P_{cL}(B_h,nf_0)+(1-k_1(B_0))P_{cH}(B_h,nf_0)].$Using this equation we could also analyze core losses including higher harmonic induction under different maximum magnetic induction, different amplitude of higher harmonic induction with different harmonic frequencies.