• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.5
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• pp.43-51
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• 1996

An appropriate lighting standard for the museum is needed to minimize the deterioration of the exhibits by the light. To obtain the basic data for the standard, a system to measure the color change of the artifacts as a function of the radiation energy frequency was constructed. Xenon lamp is used as a light source, and the light is irradiated to the samples through serveral cut-off filters. Measuring the colors of the samples under each filters, color change of the samples is estimated for each frequency ranges of radiation energy. As a result, natural dyes show severe color change in a short time, but traditional papers shows relatively small color change. Using measured results, color change due to other light sources can be calculated and this will be the base of the standard.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.9
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• pp.1739-1747
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• 1994

This study is concerned with a feeding method of microstrip patch antennas with different widths as feeding elements in order to obtain the appropriate radiation patterns of nonuniform array antennas. We analyze a microstrip patch antenna based on the transmission line model and derive that the ratio of current is equal to that of the input impedances of array antenna elements in case that the feed-line length between elements of array antenna is equal to the integer times of $\lambda_g$. We measure the radiation patterns of the nonuniform microstrip patch array antenna with 6 and 9 elements. The patterns measured are well agreed with the theoritically calculated patterns. Thus, this result can be utilized in the implementation of a feed network in nonuniform array antennas.

• Speech Sciences
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• v.10 no.3
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• pp.213-224
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• 2003

Spoken sound includes not only speaker's source but the characteristics of vocal tract and speech radiation. This paper is based on the theory of Park[1], who proposes the Phonation Type Index k; a variable that shows the characteristic of speaker's source excluding those of speaker's vocal tract and speech radiation. With Park's theory, we collect data by changing recording environments and expanding experimental data, and analyze the data collected to see whether or not the PTI k shows good discriminating power as a variable for speaker recognition. In the experiment, we repeatedly record 8 sentences ten times for each of 5 males in the environment of a recording room and an office, extract PTI k for each speaker, and measure the discriminating power for each speaker by using the value of PTI k. The result shows that PTI k has the excellent discriminating power of speakers. We also confirm that, even if the recording environment is changed, PTI k shows similar results.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.3
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• pp.105-109
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• 2011

With the development of medical technologies and the growth of household incomes, most of the people have become to be interested in health as it leads to significant early detection and cure of diseases. However the pattern of disease becomes diverse and it makes the imaging diagnosis department crowded with many patients. Therefore the opportunistic infection could be serious there. The hospital becomes the place which provides high risks of infection danger but it is true that the opportunistic infection of the hospital employees is not still recognized well. The imaging diagnosis department has developed a lot but it becomes the medium of secondary infection of patients and employees. So this study analyzesthe status of bacteria infection of the examination table, the handle of diagnostic equipment and the hands of radiation staffs in imaging diagnosis department of the general hospitals and individual ones. And the result shows that some bacteria were found even though it's little. We are trying to make the hospitals to be free of secondary infection securing safety measure to prevent the secondaryinfection from occurring to patients and hospital employees.

• Journal of Power System Engineering
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• v.16 no.4
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• pp.5-11
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• 2012

There were some papers for diesel engine performance tests using BDF, but few article deals with the temperature and soot concentration of Bio diesel flame. Since the flame temperature of diesel engines is so high and change rapidly, an optical method for measurement of flame temperature is known as the most effective one. The two-color method regarding the visible wavelength radiation for the soot particles in flame was applied on Bio diesel flame in order to measure flame temperature and soot concentration in a diesel engine. Photo detecting device was newly designed and employed TSL250R, photo-diode, to pick-up the light information emitted from the combustion flame. As a result, real flame temperature T, as a flame brightness temperature, through Ta1, Ta2, were obtained and finally the characteristics of KL value as a soot concentration reveal the difference of combustion information between diesel fuel, blending oil and Bio diesel fuel oil.

• Journal of radiological science and technology
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• v.43 no.3
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• pp.187-194
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• 2020

Bone mineral density is a examination to measure the amount of bone in patients with metabolic bone disease. It is a low dose, but may cause unnecessary exposure to the gonads and other organs located in the periphery when examining the lumbar and proximal femurs. Therefore, the purpose of this study was to evaluated the exposure dose for each organ exposed during the bone mineral density through simulation, and analyzed the applicability of the subject to radiation shielding devices using 3D printing materials. As a result, the highest dose was shown at 11.47 uSv in the breast during lumbar examination and 8.98 uSv in the testis during proximal femur examination. Also, the farther away from the examination site, the lower the effect of the scattering-ray. The shielding effect of using 3D printing shielding device showed high results in proportion to the effective atomic number and specific gravity of the printing material. Among the printing materials, ABS + W showed an effect of at least 78.72 to 96.3 9% compared to the existing lead material.

• Progress in Superconductivity and Cryogenics
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• v.7 no.3
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• pp.39-42
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• 2005

In this paper, the thermal characteristics of multilayer insulation (MLI) were experimentally investigated by using boil-off calorimetry method for seeking optimum standards of thermal insulation conditions. It is necessary to design the thermal insulating efficiency for applying to cryogenic instruments such as HTS power cable system. It is well known that the thermal characteristics and heat transfer of MLI are greatly affected by various MLI structures such as the number of layers and layer density, etc. However, it is difficult to know the thermal characteristics of MLI correctly. The heat leak by MLI between room temperature and liquid nitrogen temperature was measured at various conditions using a cylindrical cryostat. The cryostat consists of two guard vessels located at both end sides and a test vessel between them. The guard vessels are also filled with liquid nitrogen to prevent radiation heat leak through the both end side of the cylindrical test vessel to measure the heat leak only through MLI.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.261-266
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• 2007

A natural FeOOH-goethite was compressed up to 9.5 GPa at room temperature using a DIA-type large volume apparatus with synchrotron radiation. Energy dispersive x-ray diffraction method was employed to measure its compressibility and NaCl was used for high pressure determinations. Bulk modulus was determined to be 131.1 (${\pm}5.8$) GPa by the Birch-Murnaghan equation of state with $K_0'$ fixed to 4. The present result is not in accord with the previous measurements, which vary from 111 to 147.9 GPa.

• Journal of Radiation Industry
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• v.6 no.1
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• pp.41-47
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• 2012

A field tracer experiment using a radioisotope was conducted to analyze the transport and dispersion characteristics of pollutants in the coastal area near a Wolsung. A rod float including GPS was released to track the paths of radioisotope. NaI detector was installed to measure the released radioisotope from the boat, and measurements were performed with the real time. The measured tracer data by a field experiment can be used as the basic data for understanding the transport characteristics of pollutants and verifying numerical models near the offshore.

• Nuclear Engineering and Technology
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• v.34 no.2
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• pp.142-145
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• 2002

CaSO$_4$:Dy thermoluminescence dosimeter (TLD) is widely used as a personal or environmental dosimeter because of its high sensitivity to radiation. There are many methods to make pellets from the TL phosphorss[l-5]. Sintered pellets were made from a mixture of CaSO$_4$:Dy phosphor and Teflon powder is the most common method. But this method has disadvantage that CaSO$_4$:Dy pellet does not have very high sensitivity because of large amounts of Teflon in Pellets. This Paper described development of a new type of CaSO$_4$:Dy pellets by using P- compounds as a bonding material (KCT-300), and compared the TL sensitivity with that of the commercialized Teledyne CaSO$_4$: Dy pellets. Sensitivity of a new developed KCT-300 shows about 6 times than Teledyne ones, and can be used to measure very low radiation dose.