• Journal of KSNVE
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• v.8 no.2
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• pp.289-296
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• 1998

To predict the noise propagation from an elevated railway, sound radiation characteristics of elevated structure are measured by using the sound intensity method. In the base of the results, we propose the source model of elevated structure noise and the calculation model for elevated railway noise. Acoustic model of the former is modeled a row of single sources with directivity cos .theta. positioned in the center of a bogie and arranged in the lower side of slabs. Also prediction model is presented with rolling noise and elevated structure noise calculated by considering the power level of a source for one-third octave band, ground absorption and barrier deflection. Noise level unit patterns of a passing train is calculated based on this model and the results are compared with available field data.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1789-1798
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• 1994

This paper aimed for numerical simulation of complicated gas turbine combustor with swirler. For the convenience of numerical analysis, fuel nozzle and air linear hole areas of secondary and dilution zone, which are issued to jet stream, were simplified to equivalent areas of annular type. In other to solve these problems, imaginary source terms which are corresponded to supplied fuel amount were added to those of governing equation. Chemical equilibrium model of infinite reaction rate and $k-{\epsilon}-g$ model with the consideration of density fluctuation were applied. As the result, swirl intensity contributed to mixing of supplied fuel and air, and to speed up the flame velocity than no swirl condition. Temperature profiles were higher than experimental results at the upstream and lower at the downstream, but total energy balance was accomplished. As these properties showed the similar trend qualitatively, simplified simulation method was worth to apply to complicated combustor for predicting combustion characteristics.

• Journal of KSNVE
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• v.6 no.6
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• pp.843-849
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• 1996

Locations and emission characteristics of noise source of motor vehicles are great important factors to control the road traffic noise in effective ways. From results of this study on emission characteristics of engine and exhaust noise, we could find that every noise emission of different kind of vehicles has smilar pattern. The main emission locations of engine noise for the front of vehicle became the space between the road surface and bottom of the body and radiator grill, and for the side of vehicle became the space between the road surface and bottom nearby the front wheel. In case of exhaust noise of passenger-car and light truck, all the highest sound intensity level located near surface of road. But it is hard to conclude the height of noise source of driving vehicles with only results of this study. So further studies are needed to check the emission characteristics of noise.

• Journal of Hydrogen and New Energy
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• v.21 no.1
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• pp.12-18
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• 2010

Photobiological hydrogen production using Rhodobacter sphaeroides KD131 was studied on the effect of light intensities and nitrogen sources. Media containing malate and glutamate were shown higher hydrogen production rate than that containing succinate and $(NH_4)_2SO_4$ at the $110\;W/m^2$ illumination by halogen lamp at $30^{\circ}C$. Media lacking glutamate as the nitrogen source exhibited higher hydrogen production than that containing glutamate. Initial cell concentration was optimized to 1.0 at the absorbance of 660 nm. Hydrogen production was increased by increasing the light intensity from 0 to $216\;W/m^2$ but the increasing rate declined over $108\;W/m^2$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.4
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• pp.404-409
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• 2004

We fabricated photo-sensor for fluorescence detection in LOC. LOC is high throughput screening system. Our LOC screens biochemical reaction of protein using the immunoassay, and converts biochemical reaction into electrical signal using LIF(Laser Induced Fluorescence) detection method. Protein is labeled with rhodamine intercalating dye and finger PIN photodiode is used as photo-sensor We measured fluorescence emission of rhodamine dye and analyzed tendency of fluorescence detection, according to photo-sensor size, light intensity, and rhodamine concentration. Detection current was almost linearly proportional to two parameters, intensity and concentration, and was inversely proportional to photo-sensor size. Integrated LOC consists of optical-filter deposited photo-sensor and PDMS microchannel detected 50 (pg/${mu}ell$) rhodamine. For integrated LOC including light source, we used green LED as the light source and measured emitted fluorescence.

• Korean Journal of Optics and Photonics
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• v.16 no.5
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• pp.433-439
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• 2005

We have developed a biosensor reading system using a white light source and a color-sensor. To reduce the environmental effect, we used the ratio of specific color intensity to the entire white light intensity. Also we could improve the responsibility of the system by controlling the amplification of the color sensor output.

• Nuclear Engineering and Technology
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• v.56 no.10
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• pp.4219-4226
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• 2024

We present a concise equation correlating the burnup of spent nuclear fuel (SF) with the neutron count rate, developed through comprehensive data analysis from Origen-ARP and MCNP codes. This equation is applicable to Fork detectors, commonly used for verifying SF assemblies before their transfer to new storage sites. The detector is assumed to be a helium-3 detector. The reaction rate (RR) in the ³He detector is influenced by Total Neutron Source Intensity (TNSI), net neutron multiplication, and neutron capture during transit to the detector. TNSI emerges as the most influential factor. Two scenarios were explored: one involving pure water and the other with water containing 2000 ppm of boron. The characteristics of the concise equation are also analyzed.

• Journal of Photoscience
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• v.11 no.1
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• pp.35-40
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• 2004

[Ru(2,2'-bipyridine)$_2$(4,4'-dicarboxy-2,2'-bipyridine)]$^{2+}$(RuBDc) is a very photostable probe that possesses favorable photophysical properties including long lifetime, high quantum yield, large Stokes' shift, and highly polarized emission. To evaluate the usefulness of this luminophore (RuBDc) for studying macromolecular dynamics, its intensity and anisotropy decays when conjugated to RNA bacteriophage MS2 were examined using frequency-domain fluorometry with a high-intensity, blue light-emitting diode (LED) as the modulated light source. The intensity decays were best fit by a sum of two exponentials, and the mean intensity decay time was 442.2 ns. The anisotropy decay data showed a single rotational correlation time (2334.9 ns), which is typical for a spherical molecule. The use of RuBDc enabled us to measure the rotational correlation time up to several microseconds. These results indicate that RuBDc can be useful for studying rotational diffusion of biological macromolecules.s.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.319-326
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• 1998

Structural intensity of plates experiencing bending vibration is analytically evaluated using the modal analysis based on the assumed mode method. In the analysis, material internal loss and localized damping are considered. The power obtained by structural intensity integration over the circle containing the excitation source is compared with the power injected into plates to verify the accuracy of the presented method and; to evaluate the convergence of mode superposition. The intensity integration is carried out varying the circle radius and the integral step to investigate their effects in case of the power estimation using structural intensities. In addition, the dominant component among internal forces in the energy transfer by the bending vibration of a stiffened plate is investigated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.1
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• pp.9-17
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• 2011

Development of high efficiency and eco-friendly LED source has been progressed continuously. Also, by nation's regulations, public institutions have changed existing luminaires to LED luminaires. However, there are several differences between existing luminaires and the intensity distribution of general planar LED luminaires. In case of changing existing luminaires to LED luminaires, by such differences, there are inefficiencies both quality aspect and energy aspect in luminous environment. Therefore, this study aims to conduct a study on the changes of intensity distribution and luminous environment by reflector shapes in indirect reflected LED luminaires with software for optical design of a luminaire (Photopia 2.0) and lighting design of a space (ReluxPro). This study shows the changes of intensity distribution and luminous environment of indirect reflected LED luminaires and indirect fluorescent lamp luminaires by reflector shapes.