• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.328-334
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• 2024

The activation method of metallic foils is an important technique to measure the flux and energy of proton beams. In this paper, the method was used to measure the CSNS APEP proton flux at seven nominal proton energies ranging from 10 MeV to 70 MeV for beam spot sizes of the 20 mm × 20 mm and 50 mm × 50 mm. The reactions of ^natTi(p, x)⁴⁸V, ^natNi(p, x)⁵⁷Ni, ^natCu(p, x)⁵⁸Co, and ²⁷Al(p, x)²⁴Na were employed to measure the proton beam flux with a range of 10⁷-10⁹ p/cm²/s. Furthermore, we also proposed a method using the activity ratio with a stacked-foil target to determine the energy spread of a Gaussian-like distribution for different nominal proton energies. The optimal combinations of Al, Cu, Ti, Ni, Mo, Fe, Nb, and In foils were adopted for the proton energies. The measured energy spreads for degraded beams of 30 MeV-70 MeV were found to be smaller than 10.00%.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.257-263
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• 2021

This study derives the relative cross-section for the natW(p,xn)176Re nuclear reaction by measuring the gamma rays generated from the nuclear reaction with natural tungsten using a 100 MeV linear accelerator of the Korea Multi-purpose Accelerator Complex in the Korea Atomic Energy Research Institute. In general, research on isotopes with a short half-life always shows a tendency that the intensity of radioactivity decreases rapidly within a short period of time, making it very difficult to measure itself. In particular, 176Re is one of the relatively short radionuclides with a half-life of 5.3 minutes. In this study, 109.08 keV gamma rays generated from the 176Re isotope having such a short half-life were measured using a high-purity Ge detector(HPGe detector). The obtained relative measurements were the results in the 8 to 14 MeV proton energy domain published by Richard G. in 1967, and the TENDL-2019 value, which was the result of A. J. Koning in 2019, which evaluated the nuclear reaction cross-section by calculation based on this comparative analysis was performed. The results of this study are expected to be usefully applied to the design of nuclear fusion reactor which is known as future energy sources, elements ratio for the nuclear synthesis of astrophysics.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2572-2580
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• 2020

Emerging gamma ray detection applications that utilize neutron-based interrogation result in the prompt emission of high-energy (>2 MeV) gamma-rays. Rapid imaging is enabled by scintillators that possess high density, high atomic number, and excellent energy resolution. In this paper, we evaluate the bright (50,000 photons/MeV) oxide scintillator, cerium-doped Gd₂Al₂Ga₃O₁₂ (GAGG(Ce)). A silicon photomultiplier (SiPM) array is coupled to a GAGG(Ce) scintillator array (12 × 12 pixels) and integrated into a coded-aperture based gamma-ray imaging system. A resistor-based symmetric charge division circuit was used reduce the multiplicity of the analog outputs from 144 to 4. The developed system exhibits 9.1%, 8.3%, and 8.0% FWHM energy resolutions at 511 keV, 662 keV, and 1173.2 keV, respectively. In addition, a pixel-identification resolution of 602 ㎛ FWHM was obtained from the GAGG(Ce) scintillator array.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3855-3863
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• 2022

An evaluation of the radiation shielding performance of high-Z-particle-loaded polylactic acid (PLA) composite materials was pursued. Specimens were produced via fused deposition modeling (FDM) using copper-PLA, steel-PLA, and BaSO₄-PLA composite filaments containing 82.7, 75.2, and 44.6 wt% particulate phase contents, respectively, and were tested under broad-band flash x-ray conditions at the Sandia National Laboratories HERMES III facility. The experimental results for the mass attenuation coefficients of the composites were found to be in good agreement with GEANT4 simulations carried out using the same exposure conditions and an atomistic mixture as a model for the composite materials. Further simulation studies, focusing on the Cu-PLA composite system, were used to explore a shield design parameter space (in this case, defined by Cu-particle loading and shield areal density) to assess performance under both high-energy photon and electron fluxes over an incident energy range of 0.5-15 MeV. Based on these results, a method is proposed that can assist in the visualization and isolation of shield parameter coordinate sets that optimize performance under targeted radiation characteristics (type, energy). For electron flux shielding, an empirical relationship was found between areal density (AD), electron energy (E), composition and performance. In cases where ${\frac{E}{AD}}{\geq}2MeV{\bullet}cm{\bullet}g^{-1}$, a shield composed of >85 wt% Cu results in optimal performance. In contrast, a shield composed of <10 wt% Cu is anticipated to perform best against electron irradiation when ${\frac{E}{AD}}<2MeV{\bullet}cm{\bullet}g^{-1}$.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2740-2747
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• 2024

The sintering process acquired ferromagnetic copper ferrite ceramic material with a small concentration of Ni ion at 1100 ℃ for 1 h. Previously, copper ferrite with Ni proportions powder was acquired by the wet chemical process according to the relation CuFe_2-xNi_xO₄ where x takes values 0.0, 0.015, 0.03, 0.04, and 0.05. The role of Ni ion in the copper ferrite structure was investigated by X-ray analysis, Scanning electron microscope, EDX analysis, and density measurements. The gamma-ray shielding properties for the fabricated CuFeNiO ceramics samples were evaluated using the Monte Carlo simulation method. The obtained results show an enhancement in the linear attenuation coefficient for the fabricated ceramics with increasing the insertions of Ni ions within the fabricated samples, where increasing the Ni ions concentration between 0 and 1.19 wt% increases the linear attenuation by between 1.581 and 1.771 cm^-1 (at 0.103 MeV), 0.304-0.338 cm^-1 (at 0.662 MeV), and 0.160-0.178 cm^-1 (at 2.506 MeV), respectively. Simultaneously, the radiation protection efficiency for a 1 cm thickness of the fabricated samples increased between 14.8 and 16.3% with increasing the Ni ions between 0 and 1.19 wt%. Although the Ni doping concentration does not exceed 1.5 wt% of the total composition of the fabricated ceramics, the shielding capacity of the fabricated ceramics was enhanced by more than 11%, along the studied energy interval. Therefore, the fabricated samples can be used in gamma-ray shielding applications.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.201-208
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• 2004

This study was performed to examine the effects of catalase and $\beta$-mercaptoethanol ($\beta$ME) on the establishment of clonal lines from porcine fetal fibroblast cells. Fibroblasts derived from a pig fetus (Day 50) were passaged two times before use. A single cell was seeded in 96-well plates and cultured in medium supplemented with or without catalase or $\beta$ ME. Cell colonies were passaged two times into 4-well dish. Cell lines with proliferating potential were classified as an established clonal cell line. In experience 1, the establishment efficiencies were examined by addition of catalase (100ng/$m\ell$) or $\beta$ME (100 uM) in culture medium. The establishment efficiency of $\beta$ME-added group (8.3％) was significantly higher than that of control group (3.2％, P<0.05). However, catalase did not have a positive efffct on the establishment efficiency. In experience 2, the establishment efficiencies were examined by addition of different concentrations of catalase (0-1,000 ng/$m\ell$) in culture medium. However, establishment efficiencies were not different among the different concentrations of catalase (0-2.6％). In experience 3. the establishment efficiencies were examined by addition of different concentrations of $\beta$ME(0-1,000 uM) in culture medium. The establishment efficiency was significantly higher in 100 uM $\beta$ME-added group (9.4％) compare to others (0-1.6％). The result of present study shows that the establishment efficiency of clonal cell lines can be enhanced by the culture in media supplemented with 100uM $\beta$ME. However, catalase did not have a positive effect on the establishment efficiency.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.1-9
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• 2007

Cellular operators develop high speed mobile internet and multi-function cellular phones to activate new business model based on mobile internet services. Domestic cellular operators evolve their mobile networks from cdma2000-1x and EvDo to HSDPA to activate high speed mobile internet services. They also develop mobile internet platforms such as WIPI, BREW, and J2ME on multi-function cellular phones having multimedia solutions such as camera, MP3, MPEG, 3D game engine, DMB, PAN such as bluetooth, IrDA, W-LAN, and location information using GPS. But, content providers have problems of redevelopment of the same mobile internet application on different mobile internet platforms provided by cellular operators. In this paper, we develop conversion solutions for interoperability of mobile internet applications on WIPI and BREW using an one-pass compiler. We confirm the performance the proposed conversion solutions for the API conversion rate, the converted file size, and the full conversion time using the popular mobile games which are the killer applications on WiPI and BREW.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.823-826
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• 2008

This paper will show how to design home network management system in the wired/wireless environment using graphical language LabVIEW, J2ME and to apply the design to monitoring and remote controling for the information devices at home. This paper also provides with efficiency of device control and current status check according to the circumstances of administrators by constructing the wire/wirelessly integrated administration system. It means the administrators can access to central administration server and acquire the control right through web being able to operate the system with flexibility and can access to the server without computer whenever, wherever they need to control and administrate it through this wired/wireless unit easily.

• Journal of Korea Game Society
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• v.8 no.4
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• pp.87-93
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• 2008

The game engine has executed an application after making a mobile 3D game engine which is based on mobile 3D standard graphic API using openGL-ES so far. But, We could not do it satisfactorily that contents compatibility of various types as a various low-level's function is supported. At this point, This study introduce a mobile 3D game engine which is based on mobile 3D standard graphic API using JSR-184 that supporting a high-level's API more than openGL-ES and optimizing to Java environment on J2ME in the center of GSM phone. Also, We shows that the proposed skinned-mesh scheme for enhancing the process speed of a 3D object on JSR-184 engine. The experimental results are shown.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.4
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• pp.54-59
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• 2002

By the emerging information technologies, the environment and technology of manufacturing system is rapidly changing. Shipbuilding is not the exception, and lots of information technologies are utilized in design and production system. In this paper, we tried to implement the XML-based PDM(Product Data Management) system using wireless programming with J2ME MIDP. From this study the possibility to enhance the communication efficiency between the PDM system and production engineers was assured