• Magazine of the Korea Concrete Institute
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• v.7 no.4
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• pp.169-179
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• 1995

The purpose of this study is to spread beam plastic hinging zone of the high-strength($f'_c=700kg/cm^2$) reinforced concrete beam-column joints away from the column face by vertically anchored intermediate reinforcements. The newly proposed intermediate reinforcements which are vertically anchored by interlinking each intermediate rebars are tested to insure the ductile behavior of R /C beam-column joins. Main variable is the shape of intermediate reinforcements. From the test results, the newly proposed intermediate rebar detail can move arid expand the beam plastic hinging zone about 1.Od from column face and can delay the strength decay of the high-strength R /C beam-column joint. Also energy dissipation capacity of specimen IV-1.OD10 which is reinforced by vertically anchored intermediate rebars about 1.0d is 1.6 times as high as the specimen CM-STAN which is designed by ACI318-89.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1600-1609
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• 2017

The accelerator-driven subcritical system (ADS) is driven by a neutron source from spallation reactions introduced by the injected proton beam. Part of the neutron source has energy as high as a few hundred MeV to a few GeV. The effects of high-energy source neutrons ($E_n$ > 20 MeV) are usually approximated by energy cut-off treatment in practical core calculations, which can overestimate the predicted proton beam current in the ADS design. This article intends to quantize this effect and propose a way to solve this problem. To evaluate the effects of high-energy neutrons in the subcritical core, two models are established aiming to cover the features of current experimental facilities and industrial-scale ADS in the future. The results show that high-energy neutrons with $E_n$ > 20 MeV are of small fraction (2.6%) in the neutron source, but their contribution to the source efficiency is about 23% for the large scale ADS. Based on this, a neutron source efficiency correction factor is proposed. Tests show that the new correction method works well in the ADS calculation. This method can effectively improve the accuracy of the prediction of the proton beam current.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.54-57
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• 2006

The purpose of this study is to estimate the shear strength of high-strength SFRC beam by the comparison of normal-strength SFRC beam. To achieve the goal of this study, 9th specimens were made and tested. From the analyzing test result and previous researches, the shear strengthening effect of steel fiber in high-strength is evaluated as superior than normal-strength concrete. And the proposed shear strength equation of SFRC is underestimated the shear capacity of high-strength SFRC beam. Finally, the shear strengthening effect of steel fiber in high-strength concrete is evaluated about 3.5 times larger than normal-strength concrete.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.459-460
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• 2006

Electron beam manufacturing system can be used to make patterns that are smaller than can a photolithography. In this system, High voltage generator is a fundamental element for stable beam. We used high voltage with transformer. However, this instrument has several problems (for examples, dimensions, buying parts, simplicity of control circuit). For solving these problems, a commercial product is considered. This is developed for SEM(Scanning Electron Microscope). In this paper, we designed a control circuit for a commercial product and analyzed performance.

• Computers and Concrete
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• v.12 no.6
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• pp.831-850
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• 2013

The high strength materials have been more widely used in reinforced concrete structures because of the benefits of the mechanical and durable properties. Generally, it is known that the ductility decreases with an increase in the strength of the materials. In the design of a reinforced concrete beam, both the flexural strength and ductility need to be considered. Especially, when a reinforced concrete structure may be subjected an earthquake, the members need to have a sufficient ductility. So, each design code has specified to provide a consistent level of minimum flexural ductility in seismic design of concrete structures. Therefore, it is necessary to assess accurately the ductility of the beam sections with high strength materials in order to ensure the ductility requirement in design. In this study, the effects of concrete strength, yield strength of reinforcement steel and amount of reinforcement including compression reinforcement on the complete moment-curvature behavior and the curvature ductility factor of doubly reinforcement concrete beam sections have been evaluated and a newly prediction formula for curvature ductility factor of doubly RC beam sections has been developed considering the stress of compression reinforcement at ultimate state. Based on the numerical analysis results, the proposed predictions for the curvature ductility factor are verified by comparisons with other prediction formulas. The proposed formula offers fairly accurate and consistent predictions for curvature ductility factor of doubly reinforced concrete beam sections.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.2123-2138
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• 1994

A study on the dynamic mechanical properties of the high strength carbon fiber epoxy composite beam was carried out. The macromechanical model was used for the theoretical analysis of the symmetric laminated composite beam. The anisotropic plate theory and Bernoulli-Euler beam theory were used to predict the effective flexural elastic modulus and the specific damping capacity of laminated composite beam. The free flexural vibration and torsional vibration tests were carried out to determine the specific damping capacities of the unidirectional laminated composite beam. The vibration tests were performed in a vacuum chamber with laser vibrometer system and electromagnetic hammer to obtain accurate experimental data. From the computational and experimental results, it was found that the theoretical values with the macromechanical analysis and the experimental data of symmetric laminated composite beam were in good agreement.

• Progress in Medical Physics
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• v.31 no.3
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• pp.71-80
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• 2020

This paper provides a brief review of the advanced technologies for carbon ion radiotherapy (CIRT), with a focus on current developments. Compared to photon beam therapy, treatment using heavy ions, especially a carbon beam, has potential advantages due to its physical and biological properties. Carbon ion beams with high linear energy transfer demonstrate high relative biological effectiveness in cell killing, particularly at the Bragg peak. With these unique properties, CIRT allows for accurate targeting and dose escalation for tumors with better sparing of adjacent normal tissues. Recently, the available CIRT technologies included fast pencil beam scanning, superconducting rotating gantry, respiratory motion management, and accurate beam modeling for the treatment planning system. These techniques provide precise treatment, operational efficiency, and patient comfort. Currently, there are 12 CIRT facilities worldwide; with technological improvements, they continue to grow in number. Ongoing technological developments include the use of multiple ion beams, effective beam delivery, accurate biological modeling, and downsizing the facility.

• Journal of Korean Society of Steel Construction
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• v.24 no.1
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• pp.13-21
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• 2012

Recently, the development of high-strength thicker steel plate above 600MPa is becoming active due to the increase in both height and member size of architectural structure. However, such steel, which is being investigated in Korea nowadays, has possibility of limited practical application because of high design code strength and high-yield ratio. Therefore, this study performed the validation for the structural performance of beam-column with combined axial force and bending moment whether this beam-column might be attributable as an architectural purpose steel. This study was conducted from the result of monotonic loading test of beam-column, based on the material properties of low-yield, 600MPa class steel which was developed during 1988-1993 in Japan. This study might provide the fundamental database for practical research for these steel which are actively being tested in Korea.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.6
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• pp.283-292
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• 2015

In the moment frame subjected to earthquake loads, beam-column joint is structurally important for ductile behavior of a system. ACI Committee 352 proposed guidelines for designing beam-column joint details. The guidelines, however, need to be updated because of the lack of data regarding several factors that may improve the performance of joints. The purpose of this study is to investigate the seismic performance of reinforced concrete exterior joints with high-strength materials and unbonded tendons. Three specimens with different joint shear demand-to-strength ratios were constructed and tested, where headed bars were used to anchor the beam bars into the joint. All specimens showed satisfactory seismic behavior including moment strength of 1.3 times the nominal moment, ductile performance (ductility factor = at least 2.4), and sufficiently large dissipated energy.

• Proceedings of the IEEK Conference
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• 2004.06b
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• pp.359-362
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• 2004

Electron beam on high energy acceleration, which travels deeply and sharply through photoresist, became to be used in e-beam lithography apparatus for nano-patterning in due to its high resolution. An advanced electron beam lithography simulation tool is currently undergoing development for nano-patterning. This paper will demonstrate such simulation efforts with experiments at 200 keV e-beam lithography processes on PMMA, ZEP520 of which photoresist parameters and characteristics will be explained with simulation results. Neureuther parameters was extracted from the contrast curve of the resist