• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.183-183
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• 1996

Bacteriophage T4 endonuclease V initiates the repair of ultraviolet (UV)-induced pyrimidine dimer photoproducts in duplex DNA. The mechanism of DNA strand cleavage involves four sequential stens: linear diffusion along dsDNA, pyrimidine dimer-specific binding,l pyrimidine dimer-DNA glycosylase activity, and Af lyase activity. Although crystal structure is known for this enzyme, solution structure has not been yet known. In order to elucidate the solution structure of this enzyme NMR spectroscopy was used. As a basis for the NMR peak assignment of the protein, HSQC spectrum was obtained on the uniformly $\^$15/N-labeled T4 endonuclease V. Each amide peak of the spectrum were classified according to amino acid spin systems by interpreting the spectrum of $\^$15/N amino acid-specific labeled T4 endonuclease V. The assignment was mainly obtained from three-dimensional NMR spectra such as 3D NOESY-HMQC, 3D TOCSY-HMQC. These experiments were carried out will uniformly $\^$15/N-labeled sample. In order to assign tile resonance of backbon atom, triple-resonance theree-dimensional NMR experiments were also performed using double labeled($\^$15/N$\^$13/C) sample. 3D HNCA, HN(CO)CA, HNCO, HN(CA)HA spectra were recorded for this purpose. The results of assignments were used to interpret the interaction of this enzyme with DNA. HSQC spectrum was obtained for T4 endonuclease V with specific $\^$15/N-labeled amino acids that have been known for important residue in catalysis. By comparing the spectrum of enzyme*DNA complex with that of the enzyme, we could confirm the important role of some residues of Thr, Arg, Tyr in activity. The results of assignments were also used to predict the secondary structure by chemical shift index (CSI).

• 대한전자공학회논문지SD
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• 제42권1호
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• pp.9-17
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• 2005

공진주파수 스펙트럼법을 이용하여 ZnO 와 AIN 압전박막의 임피던스 특성 및 전기기계결합계수 특성에 대해 조사하였다. 압전박막의 두께가 얇을수록 전체적인 임피던스 응답 피크의 크기가 감소하였으며, 기판의 두께가 얇을수록 응답 피크의 모드 수가 감소하는 것이 관찰되었다. 입력 Kt² 값으로부터 평가된 Kt² 값을 통해 압전박막의 두께보다 기판의 두께 변화에 대한 영향이 더 큼을 알 수 있었고, 기판의 acoustic 임피던스에 의해서도 Kt² 값이 감소함을 알 수 있었다. 전극 효과가 첨가되면 임피던스 응답 피크의 크기가 감소하였으며, 전극의 acoustic 임피던스가 커짐에 따라 응답피크는 더 작아졌다. 공진주파수 스펙트럼법에서 전극은 질량부하로 고려되기 때문에 전극 효과가 첨가된 경우 Keff² 값은 증가하며, 전극의 acoustic 임피던스가 크면 그 효과는 더 커졌다. 공진주파수 스펙트럼법을 이용한 시뮬레이션을 통해 기판, 압전체, 전극으로 이루어진 composite 공진기의 특성 분석과 설계까지도 가능함을 알 수 있었다.

• 한국재료학회지
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• 제9권3호
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• pp.240-243
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• 1999

0.9PMN-0.1PT계의 압전물성을 상전이 온도를 포함하는 $-40^{\circ}C~$100^{\circ}C$의 넓은 온도범위에서 조사하였다. 압전물서의 측정을 위해 상전이 온도 이하인 $-40^{\circ}C$에서 시편을 분극처리를 한 후 승온하면서 공진반공진법에 의해 측정하였다. $0^{\circ}C$이하에서 압전체의 필요충분조건인 압전 spectrum이 선명하게 나타남을 통해서 상전이 온도보다 충분히 낮은 온도에서 0.9PMN-0.1PT가 압전체임을 확인하였다. 상전이온도인 $40^{\circ}C$보다 훨씬 높은 $90^{\circ}C$ 정도의 온도에서도 압전 spectrum이 관찰되어 있음을 통해서 0.9PMN-0.1PT 완화형 강유전체의 경우 상전이온도 이상에서도 전기기계 변환이 일어나고 있으며 강유전체인 압전체의 성질을 띠고 있다는 것을 확인하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제47권1호
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• pp.21-28
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• 2024

This study was purpose to quantitative evaluation of comparison of the image intensity uniformity and noise power spectrum (NPS) by using American college of radiology (ACR) phantom for magnetic resonance imaging (MRI). The MRI was used achiva 3.0T MRI and discovery MR 750, 3.0T, the head and neck matrix shim SENSE head coil were 32 channels receive MR coil. The MRI was used parameters of image sequence for ACR standard and general hospital. NPS value of the ACR standard T2 vertical image in GE equipment was 7.65E-06 when the frequency was 1.0 mm^-1. And the NPS value of the ACR hospital T1 region of interest (ROI) 9 over all vertical image in Philips equipment was 9E-08 when the frequency was 1.0 mm^-1 and the NPS value of the hospital T2 ROI 9 over all vertical image in Philips equipment was 1.06E-07 when the frequency was 1.0 mm^-1. NPS was used efficiently by using a general hospital vertical sequence more than the standard vertical sequence method by using the ACR phantom. Furthermore NPS was the quantitative quality assurance (QA) assessment method for noise and image intensity uniformity characteristics was applied mutatis mutandis, and the results values of the physical imaging NPS of the 3.0T MRI and ACR phantom were presented.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1989년도 가을 학술발표회 논문집
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• pp.53-58
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• 1989

Thicknesses of the base concrete blocks for large machines were estimated by analyzing the resonance modes of mechanical vibrations. The vibration was produced by the mechanical impact and detected by a wideband conical transcuder. There signals were analyzed by FET and thicknesses were obtained by the peaks of frequency spectrum. The estimated thickness upto 100cm are in good agreement with the real ones. For the layered concrete block, the estimated thickness is dependent on the acoustic reflective index at the boundary of the two layers.

• Journal of the Optical Society of Korea
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• 제11권2호
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• pp.55-58
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• 2007

We propose a systematic method for design of fiber-optic surface plasmon resonance (SPR) sensors. We used rigorous coupled wave analysis (RCWA) for analysis of the transmission spectrum, and the (1+1) evolution strategy (ES) was employed as an optimization tool. The simulation results show that the optimization method presented here is very useful in designing fiber-optic SPR sensor for strain and temperature measurement. This algorithm can be extended to another objective function with other weighting factors and optical parameters.

• Bulletin of the Korean Chemical Society
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• 제11권2호
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• pp.85-88
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• 1990

The electron paramagnetic resonance (EPR) spectrum of the copper (II) complex with the 2-methylamino-1-cyclo-pentene-1-dithiocarboxylate (acdc) anion, $Cu(N-CH_3acdc)_2$ has been studied in the diamagnetic host lattices afforded by the corresponding divalent nickel, zinc, cadmium and mercury complexes. EPR parameters of the complex support the exclusive use of sulfur atoms by the ligand in metal binding. A combination of host lattice structure and covalency effects can be account for the observed spin-Hamiltonian parameters.

• 한국자기공명학회논문지
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• 제12권2호
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• pp.74-80
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• 2008

The local structure of defects in undoped, Si-doped, and neutron irradiated free standing GaN bulk crystals, grown by hydride vapor phase epitaxy, has been investigated by employing electron magnetic resonance(EMR), Raman scattering and cathodoluminescence. The GaN samples were irradiated to a dose of $2{\times}10^{17}$ neutrons in an atomic reactor at Korea Atomic Energy Research Institute. There was no appreciable change in the Raman spectra for undoped GaN samples before and after neutron irradiation. However, a forbidden transition, $A_1$(TO) mode, appeared for a neutron irradiated Si-doped GaN crystal. Cathodoluminescence spectrum for the neutron irradiated Si-doped GaN crystal became much broader or was much more broadened than that for the unirradiated one. The observed EMR center with the g value of 1.952 in a neutron irradiated Si-doped GaN may be assigned to a Si-related complex donor.

• 한국자기공명학회논문지
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• 제18권1호
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• pp.41-46
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• 2014

In order to obtain information on the structural geometry of $NH_4HSeO_4$ near the phase transition temperature, the spectrum and spin-lattice relaxation time in the rotating frame $T_{1{\rho}}$ for the ammonium and hydrogen-bond protons were investigated through $^1H$ MAS NMR. $T_{1{\rho}}$ for the hydrogen-bond protons abruptly decreased at high temperature and it is associated with the change in the structural geometry in $O-H{\cdots}O$ bonds. This mobility of the hydrogen-bond protons may be the main reason for the high conductivity.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.973-978
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• 2001

Noise reduction has become a major issue of the manufacturing industry. This paper describes the reduction of noise and vibration of rotary compressors. Empirical design for the present strap of the accumulator has been considered to be sufficient for the constraint of the accumulator resonance modes without thorough study. Recently, however, some researchers found out that the accumulator contributes considerably to the sound propagation. In this paper, the contribution of accumulator to the noise propagation is investigated through sound measuring experiments by checking the directivity of the noise. And, experimental modal analysis results show that frequencies of some resonance modes of the accumulator coincide with the highest peaks on sound spectrum. To demonstrate the reason for those resonance modes, a finite element analysis is conducted. Normal mode analysis of the finite element model of the rotary compressor shows the mechanism of the accumulator resonance modes.