• 한국의학물리학회지:의학물리
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• 제1권1호
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• pp.75-84
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• 1990

We have claculated the absorbed dose distributions in water phantom irradiated by high energy photon beam. PDD (Percent Depth Dose) and Beam Profile can be represented by functions of depths and distances by using one dimensional model model based on transport theory. The parameters on scattering and absorption are evaluated by using non-linear regression process method. The values neeessary for calculation are obtained by simple experiment. The calculated values are in good agreement with the measured values.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.459-460
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• 2007

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.5-8
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• 2008

본 연구에서는 고강도철근콘크리트 보-기둥 접합부의 고성능화 기술 즉 콘크리트의 고강도화, 접합부 영역의 손상을 최소화하고 보의 소성힌지를 보의 내측으로 완전히 이동함과 동시에 내진성능을 향상시키는 고성능 설계상세 기술 및 고인성섬유 복합모르타르을 도입한 시험체를 제작하고 실험을 수행하여 이력거동을 평가하였다. ${\blacksquare}$ 철근콘크리트 보-기둥 접합부의 내진성능을 향상시키고, 보-기둥 접합면에 인접하여 발생하는 소성힌지를 보의 내측으로 이동시킬 목적으로 새로운 접합부 설계상세를 도입한 정착형 중간철근(1.5d)과 이중폐쇄스터럽 보강 시험체(HJCI)는 소성힌지의 이동은 물론 내진성능이 현저히 개선 되었다. ${\blacksquare}$ 철근콘크리트 보-기둥 접합부의 철근배근 및 콘크리트 밀실타설의 문제점을 해소하고 기둥의 띠철근 및 보의 스터럽을 고인성섬유 복합모르타르(HDFRM)로 대체한 실험체 (HJRP)의 경우 안정적인 이력거동, 충분한 내력확보 및 만족스런 파괴형태를 나타내었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.333-333
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• 2011

We have investigated the breakdown properties in liquids by high voltage pulse system. High voltage pulse power system is consisted of the Marx-generator with two capacitors (0.5 ${\mu}F$, withstanding voltage is 40 kV), to which the charging voltage can be applied to maximum 30 kV DC, spark gap switch and charging resistor of 20 $M{\Omega}$. We have made use of tungsten pin electrodes of anode-cathode (A-K), which are immersed into the liquids. The breakdown voltage and current signals are measured by high voltage probe (Tektronix P6015A) and current monitor (IPC CM-1.S). Especially the high speed breakdown or plasma propagation characteristics in the pulsed A-K gap have been investigated by using the high speed ICCD camera. We have measured the electron temperature through the Boltzmann plot method from the breakdown spectrums. Here the A-K gap has been changed by 1 mm, 2 mm, and 3 mm. The used liquids are distilled water and solution of salt (0.9 %). The output voltage and current signals at breakdown in distilled water are shown to be bigger than those in saline solution. The breakdown voltage and current characteristics in liquids will be discussed in accordance with A-K gap distances. It is also found that the electron temperatures and plasma densities in liquids are decreased in conformity with A-K gap.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.522-524
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• 2004

The improvement of luminance and luminous efficiency is the one of the most important part in AC-PDPs. To achieve high luminance and luminous efficiency, high VUV emission efficiency is needed. We measured the emission spectra of vacuum ultraviolet(VUV) rays in surface discharge AC-PDP with binary and ternary gas mixtures of Ne-Xe and He-Ne-Xe. The influence of He-Ne-Xe gas-mixture ratio on excited $Xe^{\ast}$ resonant atoms and $Xe_2$$^{\ast}$ dimers has been investigated. It is found that luminous efficiency of ternary gas mixture, He-Ne-Xe, is shown to be much higher than that of binary gas mixture of Ne-Xe.

• Journal of Microbiology and Biotechnology
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• 제24권6호
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• pp.788-794
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• 2014

An extracellular ${\beta}$-glucosidase from Aspergillus niger Au0847 was purified to homogeneity by precipitation with ammonium sulfate, anion exchange, and gel filtration. The purified protein was composed of two subunits with molecular masses of 110 and 120 kDa. Au0847 ${\beta}$-glucosidase exhibited relatively high thermostability and pH stability, and its highest activity was obtained at $65^{\circ}C$ and pH 4.6, respectively. As a potential metalloprotein, its enzymatic activity was potently stimulated by manganese ion and DTT. The ${\beta}$-glucosidase displayed avid affinity and high catalytic efficiency for geniposide. Au0847 ${\beta}$-glucosidase has potential value as an industrial enzyme for the hydrolysis of geniposide to genipin.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.306-311
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• 1996

This paper persents the flexural behavior of high performance concrete beams having different concrete filling conditions. Three tests were conducted on full-scale beam specimens with design concrete compressive strength of 400 kg/$\textrm{cm}^2$. Different concrete filling conditions were intentionally made such that the first beam specimen was soundly cast to obtain the perfect concrete filling condition. Second beam specimen was cast in such a way that up to the longitudinal tensile reinforcement from the top, good concrete was filled while poor concrete was poured for the bottom part to simulate the poor workamanship, workability and unsatisfactory compaction. Third beam specimens was cast in such a way that up to the neutral axis of the beam section from the top, good concrete was filled while so did for the bottom part as the second beam specimen. The test results were analyzed in terms of load-displacement response, formation of crack, crack width, crack spacing and shift of neutral axis. An evaluation of the ductile response fo three different beam specimens was made in combination with the ultimate load accoding to the three different concrete filling conditions.

• Steel and Composite Structures
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• 제19권3호
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• pp.735-757
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• 2015

Composite bonding steel plate (CBSP) is a newly developed type of structure strengthened technique applicable to the existing RC beam. This composite structure is applicable to strengthening the existing beam bearing high load. The strengthened beam consists of two layers of epoxy bonding prestressed steel plates and the RC beam sandwiched in between. The bonding enclosed and prestressed U-shaped steel jackets are applied at the beam sides. This technique is adopted in case of structures with high longitudinal reinforcing bar ratio and impracticable unloading. The prestress can be generated on the strengthening steel plates and jackets by using the CBSP technique before loading. The test results of full-scale CBSP strengthened beams show that the strength and stiffness are enhanced without reduction of their ductility. It is demonstrated that the strain hysteresis effect can be effectively overcome after prestressing on the steel plates by using such technique. The applied plates and jackets can jointly behave together with the existing beam under the action of epoxy bonding and the mechanical anchorage of the steel jackets. The simplified formulas are proposed to calculate the prestress and the ultimate capacities of strengthened beams. The accuracy of formulas was verified with the experimental results.

• Structural Engineering and Mechanics
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• 제34권2호
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• pp.247-275
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• 2010

In this study, experimental, numerical, and analytical approaches were carried out to evaluate the behavior and prestressing effect of prestressed composite beam by external tendon and cover plate. Behavior of prestressed composite beam, load-carrying capacity, effects of prestressing, and ultimate strength were estimated. The contribution of the section increase of the prestressing method using tendon was less than the prestressing method using cover plate. In accordance with numerical and analytical approaches, the ultimate strength of the prestressed composite beam is shown to be the same value because strength is determined according to the plastic resistance moment and the plastic neutral axis; however, both plastic resistance moment and neutral axis are not affected by prestressing force but affected by sectional stiffness of the prestressing member. Based on these approaches, we concluded that the prestressing method using tendon can be useful in applications without an increase in self-weight, and the prestressing method using high-strength cover plate can be applied to reduce the deflection of the composite beam. The prestressing method using high-strength cover plate can also be used to induce prestress of the composite beam in the case of a large deflection due to a smaller sectional stiffness of the composite beam.

• 한국공간구조학회논문집
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• 제19권1호
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• pp.83-91
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• 2019

The BX composite beam is designed to have the same cross-section regardless of the size of the momentum, which is a disadvantage of the existing steel structure. Combination of the H-beam end compressive material and the H-section steel tensile reinforcement according to the moment size in a single span, It is possible to say that it is an excellent synthesis which increases the performance. When underground and overhead structures are constructed, it is possible to reduce the bending, increase lateral stiffness, reduce construction cost, and simplify joints. The seamability of the joining part is a simple steel composite beam because of the decrease of the beam damping at the center of the beam and the use of the end plate of the new end compressing material. In the case of structures with long span structure and high load, it is advantageous to reduce the material cost by designing large steel which is high in price at less than medium steel.