• 한국지구과학회지
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• 제28권4호
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• pp.491-496
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• 2007

소백산 천문대의 0.6m 광학망원경과 2K CCD 카메라를 이용하여 소행성 55 Pandora에 대한 R 필터 시계열 측광관측을 수행하였다. 관측으로부터 소행성의 자전 주기($P=4.^h8168$)와 진폭(${\Delta}R=0.281{\pm}0.001$란 구하였고, Amplitude-Magnitude 방법을 이용하여, 소행성 55 Pandora의 자전축 방향 ${\lambda}_p((^o)=342$, ${\beta}_p(^o)=64$와 세 축의 비는 a/b=1.27, b/c=1.31인 형태로 자전하고 있음을 알아내었다.

• 한국전자통신학회논문지
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• 제11권11호
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• pp.1047-1052
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• 2016

본 논문에서는 인셋 급전한 패치의 접지면에 Complementary Single Loop Resonators(: CSLRs)을 배열한 안테나의 복사패턴을 개선하기 위하여 도체 반사판 사용을 제안하였다. 제안된 안테나의 반사판은 패치의 접지면으로부터 약 ${\lambda}_0/4$ 아래에 위치하고, 크기는 패치의 약 2배 정도이다. 유전율 2.5, 두께 0.787 mm인 마이크로스트립 기판을 사용하여 안테나를 설계, 제작하여 실험하였고, Finite Element Method(: FEM) 기반의 3D EM Solver인 HFSS를 사용하여 시뮬레이션 하였다. 실험결과, 반사판이 있는 경우의 안테나 공진주파수와 정합특성은 반사판이 없을 때와 거의 동일하게 변화가 없었으나, 복사패턴은 반사판에 의해 상당히 개선되었음을 확인하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권1호
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• pp.395-399
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• 2016

Background: Whether ambient exposure to environmental pollutants leads to hematopoietic malignancies such as multiple myeloma (MM) remains to be ascertained. Therefore, we aimed to investigate the immunotyping distribution of serum monoclonal paraprotein and the environmental influence on MM and monoclonal gammopathy of uncertain significance (MGUS) in the Taiwanese population. Materials and Methods: Serum protein electrophoresis with immunosubtraction by the capillary zone electrophoresis method was performed as primary screening for MM and MGUS. Clinical, pathological, and residence data of patients were also obtained. Results: From August, 2013 to June, 2015, a total of 327 patients underwent serum protein electrophoresis with immunosubtraction. Among these, 281 demonstrated no remarkable findings or non-malignant oligoclonal gammopathy, 23 were detected to have MGUS, 18 were identified as MM, and a further 5 were found as other malignancies. The most frequent immunotyping distribution of serum monoclonal paraprotein was IgG kappa (54.3%, n=25), followed by IgA lambda (15.2%, n=7) and IgG lambda (10.9%, n=5) in subjects with gammopathy. Additionally, it was shown that the elderly (OR: 4.61, 95% CI: 1.88-11.30, P<0.01) and males (OR: 2.04, 95% CI: 1.04-4.02, P=0.04) had significantly higher risk of developing MM and MGUS. There was no obvious impact of environmental factors on the health risk of MM and MGUS evolution (OR: 0.77, 95% CI: 0.40-1.50, P=0.49). Conclusions: The most frequent immunotyping distribution of serum monoclonal paraprotein included IgG kappa, IgA lambda and IgG lambda in MM and MGUS in the Taiwanese population. The elderly and male subjects are at significantly higher risk of MM and MGUS development, but there was no obvious impact of environmental factors on risk.

• Journal of applied mathematics & informatics
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• 제25권1_2호
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• pp.67-83
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• 2007

The characteristics of steady two-dimensional laminar boundary layer flow of a viscous and incompressible fluid past a moving wedge with suction or injection are theoretically investigated. The transformed boundary layer equations are solved numerically using an implicit finite-difference scheme known as the Keller-box method. The effects of Falkner-Skan power-law parameter (m), suction/injection parameter ($f_0$) and the ratio of free stream velocity to boundary velocity parameter (${\lambda}$) are discussed in detail. The numerical results for velocity distribution and skin friction coefficient are given for several values of these parameters. Comparisons with the existing results obtained by other researchers under certain conditions are made. The critical values of $f_0$, m and ${\lambda}$ are obtained numerically and their significance on the skin friction and velocity profiles is discussed. The numerical evidence would seem to indicate the onset of reverse flow as it has been found by Riley and Weidman in 1989 for the Falkner-Skan equation for flow past an impermeable stretching boundary.

• 자원리싸이클링
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• 제16권5호
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• pp.46-50
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• 2007

[ $Eu^{2+},\;Nd^{3+}$ ]로 도핑된 $CaAl_2O_4$ 청색 형광체를 고상반응법으로 제조하였다. 1 mol% $Eu^{2+}$로 doping된 형광체에 다양한 조성의 $Nd^{3+}$를 co-doping함에 따라 고휘도, 장잔광 특성을 보였다. 제조한 형광체에 대하여 XRD, SEM, TEM, 빛발광 특성을 조사하였다. $CaAl_2O_4:Eu^{2+}:Nd^{3+}$의 넓은 밴드의 UV로 여기된 빛발광 특성이 $Eu^{2+}$의 $4f^65d^1$에서 $4f^7$ 상태로 천이에 의해 기인된 청색영역(${\lambda}_{max}=440\;nm$)에서 관찰되었다. $Nd^{3+}$로 co-doping한 형광체는 여기광을 차단하였을 때 장잔광 발광 특성을 나타내었다.

• 한국결정학회지
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• 제15권2호
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• pp.93-98
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• 2004

X-선 회절법을 이용하여 C_{28}H_{41}N_4O_4Br\;{\cdo}t\;2H_2O$의 분자 및 결정구조를 해석하였다. 이 결정의 결정계는 Triclinic이고 공간군은 Pl이며, 단위포 상수 a=9.000(1) $\AA$, b=9.312(3) $\AA$, c=9.344(2) $\AA$, $\alpha=89.37(20)^{\circ},\;\beta=68.81(3)^{\circ},\;\gamma=84.70(4)^{\circ},\;V=726.7(8){\AA},\;T=298K,\;Z=1,\;D_c=1.402Mgm^{-3}$이다. 회절반점들의 세기는 Enraf-Nonius CAD4 Diffractometer로 얻었으며 사용한 X-선은 graphite로 단색화한 $MoK{\alpha}$선$(\lambda=0.71073\;{\AA}$을 사용하였다. 분자구조는 Direct method로 풀었으며, $F_o>4{\sigma}(F_0)$인 2521개의 독립 회절 데이터에 대하여 최소 자승법으로 370개의 변수를 정밀화하여 최종 신뢰도 값 $R=5.95\%$를 얻었다.

• 농업과학연구
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• 제11권1호
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• pp.176-181
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• 1984

살충성 O,O-diethylphenylphosphate (A)와 3,5-dimethylphenyl-O,O-diethylphosphate 유도체 (B)에 의한 acetylcholinesterase(Ach E)의 phosphorylation 반응에 미치는 정량적인 자유에너지 관계(LFER)를 알아보기 위하여 Ach E의 두 작용점인 esteratic-anionic site에 대응하는 (A) 및 (B)의 P원자 및 meta 위치간의 공간직선 거리 및 알짜전하를 확장 H$\ddot{u}$ckel이론(EHT)에 의한 MO 계산 방법으로 계산하고 여러 가지 치환기상수와 $pI_{50}$ 상수를 Hammett 및 Okamoto-Brown식, Taft와 Swaln-Lupton의 DSP식에 적용한 회귀분석 결과로부터 살충작용에 미치는 정량적인 자유에너지 관계, %R과 %F를 계산하여 검토하였다. 즉, (A) 및 (B)의 살충효과는 서로 비슷하였으며 blending coefficient (${\lambda}$)는 모두 ${\lambda}$<1의 값을 나타내었다. (A) 및 (B)의 resonance effect (%R)와 field effect (%F)는 각각 %R=33.5, %F=66.5 그리고 %R=2, %F=98로 각각 계산되었는데(B)와 같이 phenyl group에 bulky한 소수성의 methyl group이 결합될수록 resonance effect($R_{\pi}$)보다는 direct through space field effect ($F_D$)가 아닌 through space field effect가 더 크게 영향을 미치게 된다는 사실을 알 수 있었다.

• 한국안광학회지
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• 제7권1호
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• pp.75-78
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• 2002

파장범위 620~820nm에서 반사가 큰 $TiO_2/SiO_2$ 33층 박박 mirror를 설계하고 전자 빔 증착 방법으로 제작하였다. 다층박막은 BK7 유리 기판에 연속적으로 증착하였다. 고반사박막 설계는 중심파장 ${\lambda}_0$ 주변에 stopband가 만들어지는 것과 같은, 고굴절률을 가지는 층($n_H$)과 저굴절률을 가지는 층($n_L$)을 반복해서 하였다. 입사각 $40^{\circ}{\pm}7^{\circ}$인 투과도 측정 스펙트럼에서 전체적으로 파장범위 620~820nm에서 99.9%의 반사를 보였다. 파장이 700~740nm에서 투과도가 큰 피크를 보였다.

• Current Applied Physics
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• 제18권11호
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• pp.1338-1344
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• 2018

Band parameters and superconductivity of yttrium hypocarbide ($Y_2C$) have been investigated. The computations are performed using first-principles pseudopotential method within a generalized gradient approximation. The equilibrium lattice parameters have been determined and compared with experiment. Moreover, the material of interest is found to be stiffer for strains along the a-axis than those along the c-axis. A band-structure analysis of $Y_2C$ implied that the latter has a metallic character. The examination of Eliashberg Spectral Function indicates that Y-related phonon modes as well as C-related phonon modes are considerably involved in the progress of scattering of electrons. By integrating this function, the value of the average electron-phonon coupling parameter (${\lambda}$) is found to be 0.362 suggesting thus that $Y_2C$ is a weak coupling Bardeen-Copper-Schrieffer superconductor. The use of a reasonable value for the effective Coulomb repulsion parameter (${\mu}^*=0.10$) yielded a superconducting critical temperature $T_c$ of 0.59 K which is comparable with a previous theoretical value of 0.33 K. Upon compression (at pressure of 10 GPa) ${\lambda}$ and $T_c$ are increased to be 0.366 and 0.89 K, respectively, showing thus the pressure effect on the superconductivity in $Y_2C$. The spin-polarization calculations showed that the difference in the total energy between the magnetic and non-magnetic $Y_2C$ is weak.

• Journal of the Optical Society of Korea
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• 제13권2호
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• pp.245-250
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• 2009

We propose a digital holographic interference analysis method based on a 2-frame phase-shifting technique for measuring an optical mirror surface. The technique using 2-frame phase-shifting digital interferometry is more efficient than multi-frame phase-shifting techniques because the 2-frame method has the advantage of a reduced number of interferograms, and then takes less time to acquire the wanted topography information from interferograms. In this measurement system, 2-frame phase-shifting digital interferograms are acquired by moving the reference flat mirror surface, which is attached to a piezoelectric transducer, with phase step of 0 or $\pi$/2 in the reference beam path. The measurements are recorded on a CCD detector. The optical interferometry is designed on the basis of polarization characteristics of a polarizing beam splitter. Therefore the noise from outside turbulence can be decreased. The proposed 2-frame algorithm uses the relative phase difference of the neighbor pixels. The experiment has been carried out on an optical mirror which flatness is less than $\lambda$/4. The measurement of the optical mirror surface topography using 2-frame phase-shifting interferometry shows that the peak-to-peak value is calculated to be about $0.1779{\mu}m$, the root-mean-square value is about $0.034{\mu}m$. Thus, the proposed method is expected to be used in nondestructive testing of optical components.