• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.9
• /
• pp.833-837
• /
• 2003

The spectral and temporal characteristics of a V-groove AIGaAs-GaAs quantum wire (QWR) laser were investigated with varying the cavity length. At cavity lengths shorter than 300 ${\mu}{\textrm}{m}$, a discrete shift in tile wavelength occurred from the n=1 to the n=2 subband due to the increased cavity losses. Utilizing this characteristic, ultrafast lasing characteristics at each subband were investigated by tile gain switching method.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.4
• /
• pp.1087-1090
• /
• 2014

A simple and general method that selectively introduces metal binding sites into a protein can greatly increase the ability to design and biosynthesize artificial metalloproteins. Here, we report the incorporation of a phenanthroline-containing amino acid (Phen-Ala) into proteins in Escherichia coli by using the $tRNA{^{Tyr}}_{CUA}$ and tyrosyl aminoacyl-tRNA synthetase pair (BpyRS) from Methanococcus jannaschii, which was originally developed for a bipyridine-containing amino acid (Bpy-Ala). The incorporation efficiency of BpyRS for Phen-Ala was comparable to that for Bpy-Ala. Because of its high metal-binding ability and characteristic spectral properties, Phen-Ala can be a useful alternative to the existing metal-chelating amino acids for the design and synthesis of artificial metalloproteins.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.30A no.3
• /
• pp.52-60
• /
• 1993

Fluttering ghost which is the most severs picture impairment in mobile TV reception under multipath fading environments can be detected by measuring the dynamic variation of the synchronizing pulse timing. And also, the occurrence-stucture of fluttering ghost are directly correlated with the multipath parameters. This paper describes the quantitative evaluating method of the mobile TV pictures impaired by multipath parameters by means of the spectral analysis of synchronizing timing fluctuation. The ghost-flutter curve derived from the spatial amplitue spectrum of synchronizing pulse timing fluctuation express well the spatial variation characteristic, and it has been found to be the quantitative evaluating measure of picture impairment in mobile reception. A correspondence between the ghost-flutter curve (and/or index) and picture quality opinion test results is established.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.4 no.2
• /
• pp.1-12
• /
• 2000

단층에 근접한 지진동에 대하여 성능이 저하되는 단자유도계의 변위응답에 대하여 연구하였다 5% 의 감쇠비를 갖는 세단계의 성능저하시스템을 5개의 단층에 근접한 지진동에 대하여 해석하였다 해석결과로부터 성능저하시스템의 비탄성 변위응답은 비저하시스템에 비하여 큰 값을 나타냄을 알 수 있었다 또한 성능저하 특성이 증가할수록 변위응답은 커지는 경향이 있다 이러한 변위증폭은 구조물의 고유주기 강도와 성능저하특성에 영향을 받으며 짧은 주기영역에서는 큰 값을 나타내며 긴 주기영역에서는 변위증폭이 거의 발생하지 않는다 단층에 근접한 각각의 지진동에 대한 변위증폭의 최대값은 1초 보다 작은 주기영역에서 비저하시스템의 4배 정도이다 변위증폭계수의 평균값은 짧은 주기영역에서는 2의 값을 가지면 구조물의 고유주기가 길어질수록 1에 수렴해 감을 알 수 있었다.

• Proceedings of the Optical Society of Korea Conference
• /
• 2006.07a
• /
• pp.521-522
• /
• 2006

Thermally expanded core fiber (TEC-fiber) Bragg gratings have been fabricated and their transmission spectrums have been analyzed. The measured spectrum shows the characteristic peak splitting caused by the grating pair formed over the expanded section that has the effective index axial distribution, which could be employed for high resolution fiber sensors. An analysis on the spectrum can also give useful informations on the effective index profile of the TEC-fiber.

• Archives of Pharmacal Research
• /
• v.19 no.2
• /
• pp.91-94
• /
• 1996

In the course of a search for antitumor agents, we found that the extract of Curcuma longa was effective in inducing apoptosis or programmed cell death (PCD) in human myeloid leukemia cells (HL-60). Active compounds for PCD were isolated from the hexanic extraction of the rhizome of Curcuma longa. With the several chromatographies, and spectral data, they were identified as ar-turmerone and $\beta-atlantone$. The present results demonstrate that the exposure of human myeloid leukemia HL-60 cells to clinically achievable concentrations of arturmerone (TU) or .$\beta-atlantone$(AT) produced internucleosomal DNA fragmentation of approximately 200 base-pair multiples, and the morphological changes characteristic of cells undergoing apoptosis or PCD. This findings suggest that these agents may exert their antitumoral activity, in part, through induction of apoptosis(PCD).

• Korean Journal of Food Science and Technology
• /
• v.11 no.3
• /
• pp.166-170
• /
• 1979

A rapid and simple method for detecting chemical preservatives was attempted on the basis of emitted fluorescence at the illumination of UVSL-25 mineral light. Absorption and fluorescence spectra of powdered samples dispersed in liquid paraffin revealed characteristic patterns depending on chemical preservatives. Detection of chemical preservatives was more readily accomplished by simultaneous comparison of spectral characteristics at long and short wave ranges of the exciting light.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.16 no.10
• /
• pp.951-963
• /
• 1991

In this paper M-ary Psk system for digital land mobile radio utilized the raised-cosine filter instead of LPF with rectangular frequency characteristic as luniting channel bandwidth are implemented to measure their performance and effect of ISI and jitter. Also the error probability is calcylated on the condition of fast Rayleihg fading, cochannel interference and AWGN, It is found that QPSK and 8-PSK system with 2-branch diversity, can be improved by 3 or 5 time of spectral effciency respectively, comparinng with one of the non diversity QPSK and 8.PSK system.

• Journal of Electrical Engineering and Technology
• /
• v.5 no.1
• /
• pp.140-145
• /
• 2010

The monitoring and the diagnosis of the faults in induction motors starting from the stator current are very interesting, since it is an accessible and measurable quantity. The spectral analysis of the stator current makes it possible to highlight the characteristic frequencies of the faults but in a wide frequency range depending on half the sampling frequency, making it very difficult to monitor on-line the faults. In order to facilitate the use of the relevant frequencies of machine faults we proposed the extraction of the frequency components using two methods, namely, the amplitude and the instantaneous frequency. The theoretical bases of these methods were presented and the results were validated on a test bench with an induction motor of 5.5 kw.

• Proceedings of the KAIS Fall Conference
• /
• 2010.05a
• /
• pp.253-256
• /
• 2010

Since the amplitude of voiced fall off at about -20dB/decade, dynamic range is often compressed prior to spectral analysis so that details at weak, high frequencies may be visible. Preemphasizing the speech, either by differentiating the analog speech $s_a$(t) prior to A/D conversion or by differencing the discrete-time s(n)=$s_a$(nT), compensating for falloff at high frequencies. The most common form of preemphasis is y(n)=s(n)-As(n-1), where A typically lies between 0.9 and 1.0 and reflects the degree of pre-emphasis. In this paper, we proposed that A is adjusted at each time by measuring the slope of envelope in frequency domain.