• Journal of Biomedical Engineering Research
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• v.5 no.1
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• pp.55-62
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• 1984

A digital spectrum analysis technique was used to estimate the tissue characteristic parameters (transmission velocity and attenuation coefficient) in the phantom study and the human liver's ultrasound scanning. The soft tissue equivalent phantom was made with the combination materials of agar, water, powdered graphite, and n-propyl alcohol. In the human study, twenty five normal subjects and three patients with liver diseases were studied using the ultrasonic reflection signals and the spectrum analysis method The following results were obtained; 1. The soft tissue-equivalent materical could be produced with various acoustic parameters by changing the composition amount of the powdered graphite and n-propyl alcohol. 2. Attenuation coefficients of normal human liver tissue were estimated to be 0. 36 dB/cm MHz$\pm$0.11. In patients with liver disese, tile attenuation coefficients were shown to be different from the above normal values.

• Journal of Photoscience
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• v.9 no.2
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• pp.460-462
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• 2002

Absorption spectra of biological specimens in the soft X-ray region have been presented with special reference to the XANES (X-ray absorption Near Edge Structure) of constituent elements. Absorption spectrum in this wavelength region is characterized by the absorption edges from which elemental content could be derived. In addition, XANES has a characteristic profile for chemical environment around the element such as chemical bond. Using the specific absorption peak we can assign not only the chemical bond but also molecules having such a chemical bond. In the present paper, absorption spectrum of DNA was measured in the wavelength range from 1.5nm to 5nm. Spectrum of Chinese Hamster Ovary (CHO) cells was compared with the DNA spectrum. XANES were distinct at the K absorption edges of major elements, C, N and O. In the spectrum of the cells prominent peaks at the L absorption edge of minor element Ca were also detectable. XANES profiles in small local areas in a cell could also be measured in combination with X-ray microscopy. These give information about local chemical environment in a cell. XANES at the phosphorus K absorption edge in a human HeLa cell was successfully obtained corresponding to a sharp and intensive XANES peak of DNA.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.26-32
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• 2011

In this study, a standard illuminant A type LED that has similar emission spectrum as the standard illuminant A was developed using LED chip(emission peak: 405[nm]) and four types of phosphors(blue, green orangered and red). Using the design of experiment for spectrum control, the trend of the change of spectrum shape influenced by the change of interaction among phosphors and their density could be examined. Computer simulation through the optimization of the design of experiment revealed that, among four phosphors, the most influential one on the shape of the spectrum was green phosphor. Using the obtained optimal combination ratio of the four phosphors, an alternative LED illuminant to the actual standard illuminant A was developed and the spectrums of these two were confirmed identical. Using this standard illuminant A type LED, a portable transmittance meter with the range of measurement error of ${\pm}1.0$[%] was developed.

• Transactions on Electrical and Electronic Materials
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• v.9 no.6
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• pp.251-254
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• 2008

Blue-white reflective cholesteric liquid crystal display was prepared by a unique method of single liquid crystal layer, the combination of yellow color liquid crystal and blue color backplane. The dopant and host combination of chlolesteric liquid crystal affects the color spectrum. The CIE chromaticity coordinates of blue and white are (0.10, 0.16) and (0.29, 0.30), respectively. The relatively low driving voltages of 32 V for blue-white display are obtained.

• Journal of IKEEE
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• v.11 no.1 s.20
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• pp.30-37
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• 2007

This paper proposes a detection method of position of OFF-switch. Each switch has the parallel path with a serial combination of passive element, its parallel path has each different frequency characteristics. Frequency characteristic of ON-switch reveals a flat spectrum irrelevant to frequency characteristic of passive element connected in parallel to its each terminal and frequency characteristic of OFF-switch reveals the same characteristic as one of passive element connected in parallel. Detection of position of OFF-switch is done by measuring the similarity of each spectrum corresponding to frequency characteristic of passive element connected in parallel to OFF-switch. The measure of their similarity is to calculate Euclidean distance between their test spectrum and reference spectrum. The spectrum with the smallest distance among reference spectrum is recognized as the spectrum of OFF-switch. The real time digital signal processing system is implemented to detect the position of OFF-switch by using spectrum matching.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.993-996
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• 2012

We investigated fluorescence and fluorescence excitation of diphenylsilane (DPS) in a solution and molecular beams in combination with the aid of the DFT method. When the molecule was photoexcited at 250 nm in a cyclohexane solution, normal and excimer fluorescences were observed in the ranges of 260-320 and 330-450 nm, respectively. The fluorescence excitation spectrum indicates that the channel leading to the intramolecular excimer formation is not efficient in comparison with the normal fluorescence. Vibrationally resolved fluorescence excitation spectra were measured for the DPS molecules cooled in pulsed supersonic expansion of He in the range 262.2-271.7 nm, in which we can see several electronic excitation spectra exhibiting the electronic band origins. We found that the simulated absorption spectrum based on the time-dependent densityfunctional theory calculations accords well with the absorption spectrum.

• Structural Engineering and Mechanics
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• v.32 no.1
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• pp.179-191
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• 2009

A stochastic response spectrum method is proposed for simple evaluation of the structural response of an actively controlled aseismic structure. The response spectrum is constructed assuming a linear structure with an active mass damper (AMD) system, and an earthquake wave model given by the product of a non-stationary envelope function and a stationary Gaussian random process with Kanai-Tajimi power spectral density. The control design is executed using a linear quadratic Gaussian control strategy for an enlarged state space system, and the response amplification factor is given by the combination of the obtained statistical response values and extreme value theory. The response spectrum thus produced can be used for simple dynamical analyses. The response factors obtained by this method for a multi-degree-of-freedom structure are shown to be comparable with those determined by numerical simulations, demonstrating the validity and utility of the proposed technique as a simple design tool. This method is expected to be useful for engineers in the initial design stage for structures with active aseismic control.

• Journal of the Korean Magnetic Resonance Society
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• v.21 no.4
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• pp.114-118
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• 2017

Here, I report solid state Dynamic Nuclear Polarization (DNP) of $^1H$ nuclear spins at 0.3 T and 4.2 K. The DNP polarizer was developed based on a commercial X-band Electron Spin Resonance (ESR) modified for DNP, in combination with a NMR console and a liquid-Helium cryostat. By detuning magnetic field, DNP spectrum was measured to find the optimal condition. At +3 mT detuned from on-resonance field, $^1H$ NMR signal of 60:40 glycerol/water frozen solution doped with 20 mM perdeuterated-Tempone was amplified 43 times. The $^1H$ spin polarization obtained at 4.2 K is over 3100 times higher than that at 300 K. The width of the DNP spectrum, which is five times broader than ESR spectrum, is inconsistent with solid effect or thermal mixing, and presumably suggests a different DNP mechanism.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.83-85
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• 2016

C-RAN (Cloud Radio Access Network) structure is the most popular approach for 5G stander, it employs CoMP (Coordinated Multiple Points Transmission/Reception) to enhance frequency utilization and increase throughput for cell-edge users. C-RAN mainly includes two parts: baseband units (BBU) and remote radio heads (RRH). In this paper we propose a new resource block allocation (spectrum allocation) scheme by the permutation and combination of BBUs, and we also use the CoMP (Coordinated Multiple Points Transmission/Reception) technique according to the different environment to improve the spectrum utilization and reduce resource waste in different environment. The simulation results expound that the scheme significantly enhances throughput and improves the spectrum utilization.

• Bulletin of the Korean Chemical Society
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• v.17 no.5
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• pp.461-463
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• 1996

The laser-induced fluorescence excitation spectrum of 7-amino-4-(trifluoromethyl)coumarin in a supersonic jet has been recorded in the 340-352 nm region. The electronic band origin was observed at 28622.8 cm-1. Vibrational assignments for the three fundamental low-frequency modes and eight combination bands have been made for the S1 electronic excited state. The out-of-plane vibrations of this molecule have been characterized from the low-frequency assignments of the spectrum. The periodic potential energy function for the CF3 torsion, which satisfactorily fits the observed data, were also determined to be V(Φ)=95X(1-cos3Φ)-32X(1-cos6Φ) where Φ is the torsional angle. The relatively low torsional barrier of 99 cm-1 in S1 state could be explained by the small steric interactions between the functional groups attached to a bicyclic ring.