• Journal of radiological science and technology
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• v.40 no.4
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• pp.627-632
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• 2017

In order to design a dual-head gantry radiotherapy system, the single head of LINAC was modeled using GATE as a preliminary study. The LINAC head was designed with VARIAN manufacturer's information. 6 MV photons were generated from the head and the photons w irradiated to a water phantom for beam evaluation. GATE simulation was segmented by two stages, the one was to generate X-ray spectrum and the other one was for irradiation X-ray to the water phantom. The quantitative results were described in Percentage depth dose and beam profile. Two field size conditions were employed as $5{\times}5$ and $10{\times}10cm^2$. After beam quality was verified, dual heads gantry radiotherapy system were simulated and they was compared to the single head of LINAC system in terms of dose deposition with in the phantom. The simulated LINAC head showed acceptable beam quality result for radiotherapy. The efficiency was calculated that deposited dose from dual heads was divided by the dose from single head. At all conditions, dual heads showed higher treatment efficiency. Efficiency was increased about 40 to 60%. Form the result, The dual head gantry system of new LINAC system will contribute to the practical radiotherapy of tumor and to reduce treatment time.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.220-225
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• 2020

Hair is made of proteins containing various amino acids. Ultraviolet (UV) radiation is believed to be responsible for the most damaging effects of sunlight, and also plays an important role in hair aging. The purpose of this study was to investigate the changes in morphological and chemical structures after ultraviolet B (UVB) irradiation of human hair. The UVB-irradiated hair showed characteristic morphological and structural changes, compared to those of the normal hair. The result from a scanning electron microscope (SEM) equipped with an energy dispersive X-ray diffractometer (EDX) showed that the scale of UV-irradiated hair appeared to be rough and the amount of oxygen element was higher than that of the normal hair. Fluorescence and three dimensional (3D) topographical images were obtained by a confocal laser scanning microscope (CLSM). In 3D images, the green emission intensity of normal hair was much higher than that of fluorescing UVB-irradiated hair. The intensity of green emission reflects the intrinsic fluorescence of hair protein. Also, a fluorescent imaging method using fluorescamine reagent was used to identify the free amino groups resulting from a peptide bond breakage in UVB-irradiated hair. Strong blue fluorescence of UVB-irradiated hair, which indicates a very high level of amino groups, was observed by CLSM. Therefore, the fluorescamine as an extrinsic fluorescence could provide a useful tool to identify the peptide bond breakage in UVB-irradiated hair. Infrared image mapping was also employed to assess the cross-sections of normal and UVB-irradiated specimens to examine the oxidation of disulfide bonds. The degree of peak areas with strong absorbance for the disulfide mono-oxide was spread from the outside to the inside of hair. The spectroscopic techniques used alone, or in combination, launch new possibilities in the field of hair cosmetics.

• Journal of Soil and Groundwater Environment
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• v.18 no.5
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• pp.7-14
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• 2013

The objectives of this study were to identify the characteristics of groundwater in the petroleum contaminated site and to evaluate the applicability of house-type landfarm facilities heated with briquette stoves in winter season. The six monitoring wells were installed at the site where pH, dissolved oxygen, and temperature were all measured. Also groundwater contaminants, benzene, toluene, ethylbenzene, xylene and total petroleum hydrocarbon, were analyzed twice. House-type two landfarm facilities ($12m{\times}40m{\times}4.8m$) each installed with four briquette stoves were constructed. During four rounds treatment process, VOCs, moisture, temperature were monitored and soil contaminants were analyzed. The pH was 6.37 and considered subacid and DO was measured to be 3.12 mg/L. The temperature of groundwater was measured to be $9.48^{\circ}C$. The groundwater contaminants were detected only in the monitoring wells within the contaminated area or close to it showing that the groundwater contaminated area was similar to the soil contaminated area. During the landfarm process, 73.3% of VOCs concentration in interior gas was decreased and moisture was lowered from 17.7% to 13.4%. In the morning, at 8:00 am, the temperature was decreased showing soil ($5.5^{\circ}C$) > interior ($4.8^{\circ}C$) > exterior ($3.5^{\circ}C$). In the afternoon, at 2:00 pm, the temperature was soil ($8.6^{\circ}C$) < interior ($9.9^{\circ}C$) < exterior ($11.5^{\circ}C$) with solar radiation. The temperature difference between interior and exterior was $0.7^{\circ}C$ in the morning, but it was $1.6^{\circ}C$ in the afternoon. A total of 130 days were taken for four round landfarm processes. Each process was completed within 33 days showing 80% of cleanup efficiency ($1^{st}$ order dissipation rate(k) = 0.1771).

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.4
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• pp.107-113
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• 1981

In order to investigate effects of fertilization on the yield of chestnut trees and to compare the compound fertilizer (CF) and Boron contained compound fertilizers (BCF) for chestnut trees developed by Chosun Fertilizer Inc. with single fertilizers (SF) at different fertilizing levels, a field experiment was conducted during the 1979 and 1980 growing periods. The results were summarized as follows: 1. The growth of chestnut trees was markedly improved as increasing the amount of fertilizers regardless of the SF, CF or BCF. 2. The number of strobiles increased as increased amount of fertilizers, and the ratio of dropped strobiles decreased by more than 90 percent by the BCF application while that decreased by 12 to 47 percents by the SF or CF applications. It implies that the boron application be necessary for increasing strobiles and reducing the ratio of dropped strobiles. 3. The yield increments by the SF or CF applications at the standard level were 80 percent and that by the BCF application at the same level was 202 percent and the highest yield increment was recorded as high as 302 percent by the BCF application at the doubled level in 1979. The yield response in 1980 was similar to that in 1979; however, the yields were lower than in 1979 due to the abnormal weather conditions such as low temperature and low solar radiation during summer except BCF applicated treatments where the yields were outstandingly increased. 4. The BCF developed proved as a recommendable compound fertilizer for chestnut trees.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2860-2866
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• 2020

Oxide dispersion-strengthened materials W-1wt%Pr₂O₃ and W-1wt%La₂O₃ were synthesized by wet chemical method and spark plasma sintering. The field emission scanning electron microscopy (FE-SEM) analysis, XRD and Vickers microhardness measurements were conducted to characterize the samples. The irradiations were carried out with a 5 keV helium ion beam to fluences up to 5.0 × 10²¹ ions/m² under 600 ℃ using the low-energy ion irradiation system. Transmission electron microscopy (TEM) study was performed to investigate the microstructural evolution in W-1wt%Pr₂O₃ and W-1wt%La₂O₃. At 1.0 × 10²⁰ He⁺/m², the average loops size of the W-1wt%Pr₂O₃ was 4.3 nm, much lower than W-1wt% La₂O₃ of 8.5 nm. However, helium bubbles were not observed throughout in both doped W materials. The effects of pre-irradiation with 1.0 × 10²¹ He⁺/m² on trapping of injected deuterium in doped W was studied by thermal desorption spectrometry (TDS) technique using quadrupole mass spectrometer. Compared with the samples without He⁺ pre-irradiation, deuterium (D) retention of doped W materials increased after He⁺ irradiation, whose retention was unsaturated at the damage level of 1.0 × 10²²D₂⁺/m². The present results implied that irradiation effect of He⁺ ions must be taken into account to evaluate the deuterium retention in fusion material applications.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.1
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• pp.60-71
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• 2019

Electrical power supply is needed to operate the radar system in the field. In addition, it should not cause performance deterioration under the environmental factors due to characteristics of military equipment, and should not cause malfunction due to electromagnetic waves generated in radar, and then should not cause malfunction in radar equipment. Therefore, By applying a permanent magnet to the rotor of the generator, light weighting and high efficiency of generator were achieved. As a result, electrical performance test of the generator, the rated output power was 80.8 kW, the maximum output power was 88.1 kW, and the output power efficiency was 98.1 % under the full load condition. When the load capacity of the generator was changed from no load to full load, the maximum voltage variation was 3.6 % and the frequency variation was 0.3 %. As a result of the transient response test for measuring the output power of the generator according to the load characteristics change, the maximum voltage variation of 7.9 %, frequency variation of 0.5 % were confirmed, and the transient response time was 2.1 seconds. Environmental tests were conducted in accordance with MIL-STD-810G and MIL-STD-461F to evaluate the operability of the generator groups. Normal operation of radar system generator group was confirmed under high temperature and low temperature environment conditions. Electromagnetic tests were conducted to check if electromagnetic wave generated from both radar system and generator group in operation caused any performance deterioration to each other. As a result, it was confirmed that the performance deterioration due to electromagnetic wave inflow, radiation, and conduction did not occur. It is expected that it should be possible to provide high efficiency power supply and stable power supply by applying to various military system as well as radar system.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.879-886
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• 2018

A 3-dimensional (D) printer is a device capable of outputting a three-dimensional solid object based on data modeled in a computer. These features are utilized in the bone model X - ray phantom production etc using CT data by fusing with the radiation science field. A bone model phantom was made using data obtained by CT scan of an existing Pelvis phantom, using PLA, Wood, XT-CF20, Glow fill, Steel filaments which are materials of Fused Filament Fabrication (FFF) 3D printer.Measure Hounsfield Unit (HU) with images obtained by CT scan of the existing Pelvis phantom and five material phantoms made with 3D printer under the same conditions,SI and SNR were measured using a diagnostic X-ray generator, and each phantom was compared and analyzed.As a result, the X - ray phantom in the X - ray examination condition of the limb was found to be most suitable for the glow fill filament.The characteristics of the filament can be known to the base of this research and the practicality of X - ray phantom fabrication was confirmed.

• Journal of the Korean Society of Radiology
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• v.12 no.6
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• pp.793-799
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• 2018

As interest in artificial intelligence has increased, artificial intelligence has been actively studied in the medical field. In Korea, artificial intelligence has been applied to medical imaging devices such as X-ray imaging, Computer Tomography and Magnetic Resonance Imaging and artificial intelligence capable of acquiring radiation images of patients without radiologists in the future Medical devices are expected to be invented. This study was an initial study on the automation of patient positioning in X - ray imaging. We used x-ray equipment and human phantoms to evaluate the positioning. The program used Visual Studio 2010 MFC and the image was in the size $1450{\times}1814$. The pixel values were converted to contrasts with values of 0 to 255 that can be visually recognized and output to the monitor. We developed a procedure algorithm program that predicts the angle of the output image through three pixel coordinate values and induces the patient to perform correct positioning according to the voice guidance according to the angle. In the next study, we will study the artificial intelligence to grasp the structure itself and calculate the angle, rather than conveying the reference of coordinates to artificial intelligence. In the future, it is expected that it will be helpful in the study of artificial intelligence from shooting to positioning through the automation of positioning.

• Korean Journal of Heritage: History & Science
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• v.45 no.1
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• pp.174-189
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• 2012

This study aims to examine the traditional living space to reflect the environment-friendly design methods and principles of reestablishment. To do so, this study carried on a related literature study and field survey. The traditional living space in terms of the environmental friendliness is reflected on site selection and space composition, and utilization of natural energy and natural materials. Focused on the Kwangajeong in Yangdong Village, this study is to identify eco-friendly techniques on the traditional living space. As a result, it shows that Kwangajeong with the side of the southeast in site selection had been considered in aspect of environmental control such as sunshine and solar radiation. Also building construction techniques had been used to minimize the variation of terrain. In aspect of environmental conservation, Kwangajeong had structurally arranged the gate, an inner yard and an inner floor to allow good ventilation. In aspect of space composition, Kwangajeong with the emphasis of scenic view had utilized the methods that attract external landscape through the control of its fences. Environment-friendly techniques and control principles in traditional space had been developed by a long experience through the long periods and the traditional techniques suitable for local climate and local environment have been developed. The technical development of these techniques to resolve the global environmental and energy issues and create a more pleasant living environment of human beings might be critical.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.164-177
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• 2011

This study aims to examine the traditional living space to reflect the environment-friendly design methods and principles of reestablishment. To do so, this study carried on a related literature study and field survey. The traditional living space in terms of the environmental friendliness is reflected on site selection and space composition, and utilization of natural energy and natural materials. Focused on the Kwangajeong in Yangdong Village, this study is to identify eco-friendly techniques on the traditional living space. As a result, it shows that Kwangajeong with the side of the southeast in site selection had been considered in aspect of environmental control such as sunshine and solar radiation. Also building construction techniques had been used to minimize the variation of terrain. In aspect of environmental conservation, Kwangajeong had structurally arranged the gate, an inner yard and an inner floor to allow good ventilation. In aspect of space composition, Kwangajeong with the emphasis of scenic view had utilized the methods that attract external landscape through the control of its fences. Environment-friendly techniques and control principles in traditional space had been developed by a long experience through the long periods and the traditional techniques suitable for local climate and local environment have been developed. The technical development of these techniques to resolve the global environmental and energy issues and create a more pleasant living environment of human beings might be critical.