• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.32-32
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• 2006

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.37.1-37.1
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• 2016

2022년부터 가동되는 거대 마젤란 망원경(GMT)은 1시간 노출로 I 필터 24등급 이상의 어두운 천체도 관측할 수 있을 것으로 예상되며, 이 경우 10초 지름의 시계 안에 3천 개 이상의 관측 가능한 천체가 존재하게 된다. 따라서 GMT를 가장 효율적으로 사용하는 방법은 은하와 항성에 대한 광시야 분광 탐사를 수행하는 것이다. 이를 위해서는 한 번에 여러 곳에 존재하는 수천 개의 천체를 동시에 분광할 수 있는 광섬유 다천체 분광기기가 필요하지만, 현재까지 제안된 GMT의 1세대 기기 중에서는 이를 동시에 만족하는 기기가 없다. 본 발표에서는 가시광선 영역의 분광기 13대를 연결하여 2천 개의 천체를 동시에 분광하는 기기의 개념 설계를 제안하고, 현재 논의되고 있는 다른 다천체 분광기기 디자인과의 비교를 수행한다.

• Current Optics and Photonics
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• v.6 no.1
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• pp.104-113
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• 2022

We present a method to count the overall length of the zoom system in an initial design stage. In a zoom-lens design using the concept of the group, it has been very hard to precisely estimate the overall length at all zoom positions through the previous paraxial studies. To solve this difficulty, we introduce T_eq as a measure of the total track length in an equivalent zoom system, which can be found from the first order parameters obtained by solving the zoom equations. Among many solutions, the parameters that provide the smallest T_eq are selected to construct a compact initial zoom system. Also, to obtain an 8× four-group zoom system without moving groups, tunable polymer lenses (TPLs) have been introduced as a variator and a compensator. The final designed zoom lens has a short overall length of 29.99 mm, even over a wide focal-length range of 4-31 mm, and an f-number of F/3.5 at wide to F/4.5 at tele position, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.425-430
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• 2012

By the theories of the physics, the phenomena in the world are understood. And also these theories gave the influence to design the architecture. In this research, the contents which the thought of the physics gives a influence a building design is considered, and try to suggest the interrelation between the physics and architectural design. As the result, the architectural design on the influence of classical physics is based on the homogeneous space and the design focus on the style or form of the building with a geometry plan which is not concerned of the place. On the other hand, contemporary architectural design is based on the thought of the modern physics. By this concepts, the architecture is understood as the area contain the conditions of the circumstance and by interaction between buildings and the environment and by various viewpoints like cubism. And the architecture which is settled recently is shown of the diversity and atypical form.

• Journal of the Korean Mathematical Society
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• v.34 no.4
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• pp.949-957
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• 1997

The purpose of this paper is to establish connection between certain complex of modules of generalized fractions and the concept of cosequence in commutative algebra. The main theorem of the paper leads to characterization, in terms of modules of generalized fractions, of regular (co) sequences.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.231-233
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• 2007

The e-Science for High Energy Physics is to study high energy physics anytime and anywhere even if we are not on-site of accelerator latboratories. The concepts are 1) data production, 2) data processing and 3) data publication. The data production is to do remote control and take shifts remotely. The data processing is to run jobs anytime, anywhere with grid farms. The data publication is to work together to publish papers using collaborative environment such as EVO (Enabling Virtual Organization) system. We apply this concept to high energy physics, espessically, CDF experiment and show the results.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.168-169
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• 2000

We have tried to enhance the density of the near-field optical memory and to improve the recording/readout speed. The current optical memory has the limitation in both density and speed. This barrier due to the far-field nature can be overcome by the use of the near-field$^{(1)}$ . The optical data storage density can be increased by reducing the size of the nanometric aperture where the near-field is obtained. To fabricate the aperture in precise dimension, we applied the orientation-dependent / anisotropic etching property of crystal Si often employed in the field of MEMS$^{(2)}$ . And so we fabricated the 10$\times$10 aperture array. This array will be also the indispensable part for speeding up. One will see the possibility of the multi-tracking pickup in the phase changing type memory through this array$^{(3)}$ . This aperture array will be expected to write the bit-mark whose size is about 100nm. We will show the recent result obtained. (omitted)

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.741-751
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• 2021

There has been a deep interest in trying to find better-performing fuel clad motivated by the desire to decrease the likelihood of the reactor barrier failure like what happened in Fukushima in recent years. In this study, the effect of move towards accident tolerant fuel (ATF) cladding as the most attracting concept for improving reactor safety is investigated for SMART modular reactor. These reactors have less production cost, short construction time, better safety and higher power density. The SiC and FeCrAl materials are considered as the most potential candidate for ATF cladding, and the results are compared with Zircaloy cladding material from reactor physics point of view. In this paper, the calculations are performed by generating PMAX library by DRAGON lattice physics code to be used for further reactor core analysis by PARCS code. The differential and integral worth of control and safety rods, reactivity coefficient, power and temperature distributions, and boric acid concentration during the cycle are analyzed and compared from the conventional fuel cladding. The rod ejection accident (REA) is also performed to study how the power changed in response to presence of the ATF cladding in the reactor core. The key quantitative finding can be summarized as: 20 ℃ (3%) decrease in average fuel temperature, 33 pcm (3%) increase in integral rod worth and cycle length, 1.26 pcm/℃ (50%) and 1.05 pcm/℃ (16%) increase in reactivity coefficient of fuel and moderator, respectively.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.1736-1746
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• 2021

The results of full-scale numerical experiments of a hybrid thorium-containing fuel cell facility operating in a close-to-critical state due to a controlled source of fusion neutrons are discussed in this work. The facility under study was a complex consisting of two blocks. The first block was based on the concept of a high-temperature gas-cooled thorium reactor core. The second block was an axially symmetrical extended plasma generator of additional neutrons that was placed in the near-axial zone of the facility blanket. The calculated models of the blanket and the plasma generator of D-T neutrons created within the work allowed for research of the neutronic parameters of the facility in stationary and pulse-periodic operation modes. This research will make it possible to construct a safe facility and investigate the properties of thorium fuel, which can be continuously used in the epithermal spectrum of the considered hybrid fusion-fission reactor.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.261-261
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• 1999

We observed leveling-off of the resistance in granular In/InO$_x$ thin films in the zero-temperature limit. The temperature T$_b$ at which the leveling-off appears gets larger as the sheet resistance R$_n$ increases. This is consistent with the concept that the leveling-off of the resistance is due to the dissipation of the bosonic phase and that the dissipation is enhanced as the resistance increases. The magnetic field dependence of the saturated resistance R$_b$ at low temperatures fits the modified square-root cusp-like form R$_b$/R$_n$=α exp[-b(B/B$_c$-1)$^{-1/2}$] for the magnetic field in the range B$_c$$_f$ where B$_c$ is the onset magnetic field of the resistance leveling-off. α and b are constants of order 1. For B>B$_f$ tansport properties are described by the theory of the fermi insulator. From the results, we attribute the leveling-off to the dissipative quantum tunneling of vortices, which supports the models predicting the vortex-motion-induced insulating phase related with the concept like"dirty boson" [1]l and "hose metal" [2].