• 한국구조물진단유지관리공학회 논문집
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• 제8권3호
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• pp.169-176
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• 2004

황산염에 의한 원전 콘크리트 구조물의 침식을 예측하기 위하여 경과시간에 따른 팽창응력, 확산계수 등을 종합적으로 고려할 수 있는 Mechanistic 모델을 적용하였다. 적용배합은 원전 구조물 건설에 사용되었던 설계기준강도 385, 280 및 $210kgf/cm^2$의 3종으로 하였으며, 1종과 5종 포틀랜드시멘트를 시용하였다. 또한 시멘트 종류 및 설계기준강도별 로 1년간 10% 황산나트륨 용액에서 침지실험을 실시하여 각 배합별 확산계수 및 압축강도를 구하였으며, 그 결과를 예측모델식에 사용하여 원전 콘크리트 구조물의 황산염 침식을 예측하였다. 대상 배합의 황산염 확산계수는 $0.5763{\sim}3.9002{\times}10^{-12}m^2/sec.$였으며, 원전 콘크리트 구조물의 황산염 침식속도는 0.1~7.1 mm/year로 예측되었다.

• 동력기계공학회지
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• 제9권1호
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• pp.50-56
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• 2005

The corrosion experiment was performed for 120 hours on the specimens in the natural seawater tank with four steps of the loaded torsional stress. The surface corrosion pattern of SCM440 area was showed global corrosion and narrow pitting, that was cause by galvanic corrosion between friction welded IN713LC and SCM440. But corrosion does not proceeded from IN713LC area. Initially, the average relative electrode potential and corrosion current were decreased suddenly, by and large, it was stabilized gradually tend to decreasing with the elapse of the immersion time. The corrosion rate was decreased by increasing the load stress, but 200 MPa specimen was showed most large value.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2001년도 추계학술대회 논문집
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• pp.169-172
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• 2001

There are many people who suffer from simulation sickness when immersing in virtual reality. In this study, we analyzed two photoplethysmogram(PPG) parameters - a second derivative parameter and power spectral density ratios - in order to relate PPG parameters with simulation sickness. 36 young, healthy subjects were participated in the experiment, and each subject was equipped with a PPG electrode during his or her immersion. Simulation sickness section was defined as a 7 - second section which starts from the point where a subject reported simulation sickness, and normal section as a same-length section where no physical stimuli was presented to him or her. We compared the PPG parameters of the simulation sickness sections with the normal sections, - d/a ratio is believed to have lower value during vasodilation and higher value during vasoconstriction, however, we could not find much difference in the parameter between normal and simulation sickness sections. We also compared 1 to 10Hz power spectral density ratios in normal sections with in simulation sickness section, and found that 6 density ratios among them have different value. Therefore, the density ratios might be utilized as parameters to detect simulation sickness of subjects.

• 한국콘텐츠학회논문지
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• 제21권3호
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• pp.205-216
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• 2021

본 연구의 목적은 대학생들이 진로준비 과정에서 지각하는 내적 요인과 대학 생활을 통해 경험하는 외적 요인 간의 관계를 통해 진로 지원방안을 논의하기 위한 것이다. 이를 위해 서울 소재 K대학 927명을 대상으로 위계적 다중회귀분석, 독립표본 t검정, 일원배치분산분석을 하였다. 총 4단계로 연구모형을 설정하였으며 각 모형의 설명력은 모두 통계적으로 유의하였다. 연구결과, 모형 1과 2 모두 성별이 진로준비에 유의한 영향을 주었지만, 모형 2에 자기주도성이 추가되자 성별과 비교했을 때 자기주도성이 진로준비에 더 영향을 주는 것으로 나타났다. 모형 3에서는 비교과 만족을 추가하였으며 진로준비에 도움이 되는 것으로 나타났으며, 대학몰입을 추가한 모형 4에서는 대학몰입 즉, 대학에서 느끼는 소속감이 높을수록 진로준비에 도움이 된다고 느끼는 것으로 나타났다. 본 연구는 대학생의 개인특성과 재학 중에 경험하게 되는 진로 관련 활동, 대학몰입 간 관계를 파악하여, 이를 고려한 대학생의 진로준비 지원 정책 마련에 도움이 되길 기대한다.

• 한국엔터테인먼트산업학회논문지
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• 제13권2호
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• pp.101-110
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• 2019

영화 공간은 영화의 내적, 외적 의미들을 모두 의도할 수 있는 핵심적인 표현요소일 뿐 아니라 내러티브적인 측면에서도 극적 맥락을 주도하는 중요한 역할을 수행한다. 영화 공간은 도발적 사건이 일어나고 캐릭터 행동을 유발하는 가시적 환경을 구축할 뿐 아니라 캐릭터 심리나 서사의 정서적 의미를 내포하고 있으며, 표면 배후의 상징적 의미 및 암시적 기능을 통해 긴장을 유발하기도 한다. 따라서 본고는 이러한 내러티브 공간의 극적 기능을 중심으로 영화<시카리오>를 분석한다. 이 영화는 멕시코 마약 카르텔을 소재로 범죄스릴러 장르의 외피를 두르고 있지만, 결코 장르 관습을 따르지 않으며 깊은 철학적 고뇌를 통해 사유를 제시하는 통찰을 보여준다. 이 영화의 내러티브 공간은 도발적 사건 이상으로 극적 긴장을 불러일으키는 감정적 기능을 담당하며, 정교하게 계획되고 통제된 미장센은 궁극의 서스펜스를 구성하여 관객을 흡인한다. 결국 이 영화의 몰입감과 극적 여운은 플롯차원보다는 장면의 힘으로 이루어진 성취라 할 수 있다. 이처럼 본 연구는 <시카리오>의 공간과 시각화 구성을 분석하여 내러티브 공간과 극적 몰입의 상관관계를 설명하였다. 이를 통해 연구의 범위가 한정적이었던 극적몰입의 연구 패턴을 보다 확장시킬 수 있을 것으로 기대한다.

• Corrosion Science and Technology
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• 제4권6호
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• pp.242-249
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• 2005

A lot of parts in FGD (Flue Gas Desulfurization) systems of fossil-fuel power plants show the environments in which are highly changeable and extremely acidic corrosive medium according to time and locations, e.g. in duct works, coolers and re-heaters etc. These conditions are formed when system materials are immersed in fluid that flows on them or when exhausted gas is condensed into thin layered acidic medium to contact materials of the system walls and roofs. These environments make troublesome corrosion and air pollution problems that are occurred from the leakage of the condensed solution. To cathodically protect the metallic structures in extremely acidic fluid, the properties of the protective coatings on the metal surface were very important, and epoxy Novolac coating was applied in this work. On the base of acid immersion tests, hot sulfuric acid decreased the hardness of the coatings and reduced greatly the content of $Na_2O$, $Al_2O_3$, and $SiO_2$ among the main components of the coating. A special kind of CP(Cathodic Protection) system has been developed and tested in a real scale of the FGD facility. Applied coating for this CP system was peeled off and cracked in some parts of the facility. However, the exposed metal surface to extremely acidic fluid by the failure of the coatings was successfully protected by the new CP system.

• 한국재료학회지
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• 제9권2호
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• pp.217-225
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• 1999

The effect on the pitting corrosion resistance of laser welding and surface treatment developed as a repair method of stream generator tubing material that was a major component of primary system at nuclear power plant was observed. Some heat-treated Alloy 600 tubing materials used at domestic nuclear power plants were laser-surface observed. Some heat-treated Alloy 600 tubing materials used at domestic nuclear power plants were laser-surface melted and the microstructural characteristics were examined. The pitting corrosion resistance was examined through Ep(pitting potential) and degree of pit generation by means of the electrochemical tests and the immersion tests respectively. The pit formation characteristics were investigated through microstructural changes and the pit initiation site and pit morphology. The test results showed that the pitting corrosion resistances was increased in the order of the followings; sensitized Alloy 600, solution annealed alloy600, and laser surface melted Alloy 600. Pits were initiated preferably at Ti-containing inclusions and their surroundings in all tested specimens and it is believed that higher pitting resistance of laser-surface treated Alloy 600 was caused by fine, homogeneous distribution of non-soluble inclusions, the disappearance of grain boundary, and the formation of dense, stable oxide film. The major element of corrosion products filled in the pit was Cr. On the other hand, Fe was enriched in the deposit formed on the pit.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2261-2267
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• 2021

This paper evaluates the efficacy of magnesium potassium phosphate cements (MKPCs) as waste forms for the solidification of radioactive concrete powder wastes produced by the decommissioning of nuclear power plants. MKPC specimens that contained up to 50 wt% of simulated concrete powder wastes (SCPWs) were evaluated. We measured the porosity and compressive strength of the MKPC specimens, observing them using scanning electron microscopy and X-ray diffraction. The addition of SCPWs reduced the porosity and increased the compressive strength of the MKPC specimens. Struvite-K crystals were well-synthesized, and no additional crystal phase was formed. After thermal cycling and after immersion, MKPC specimens with 50 wt% SCPWs satisfied the waste-acceptance criteria (WAC) for compressive strength. Semi-dynamic leaching tests were performed using the ANS 16.1 method; the leachability indices of Cs, Co, and Sr were 11.45, 17.63, and 15.66, respectively, which also satisfy the WAC. Thus, MKPCs can provide stable matrices to immobilize radioactive concrete wastes generated by the decommissioning of nuclear power plants.

• 정보저장시스템학회논문집
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• 제4권1호
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• pp.1-5
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• 2008

Super-resolution near-field structure (super-RENS) technology and solid immersion lens (SIL) based near-field (NF) technology have been expected as promising approaches to increase data capacity or areal density of optical disc. Super-RENS technology has been studied until now using mainly numerical aperture (NA) of 0.85 far-field optical system and possibility of tangential data density increment have been presented. NF technology has been studied with NA over 1 and presented demonstration of removable performance. To achieve much higher density, approach to increase NA of super-RENS by NF technology (Near-Field Super-Resolution, NFSR) can be a candidate and we think this technology would be advantageous compared to wavelength reduction or much higher NA increment of NF technology or much smaller effective optical spot size reduction of far-field super-resolution technology. In this paper we present readout result of ROM media having monotone pits using NF optical system with wavelength of 405nm and NA of 1.84 surface type SIL. GeSbTe material was used for super resolution active layer and pit length is 37.5nm which is shorter than resolution limit 55nm. We present the feasibility of NFSR technology by confirming the CNR threshold according to readout power (Pr) and CNR 33dB over threshold Pr.

• 천문학회보
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• 제38권2호
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• pp.84.1-84.1
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• 2013

We present a python-based data reduction pipeline for the Immersion GRating INfrared Spectrograph (IGRINS). IGRINS covers the complete H- and K-bands in a single exposure with a spectral resolving power of greater than 40,000. IGRINS is designed to be compatible with telescopes of diameters ranging from 2.7-m (the Harlan J. Smith telescope at McDonald Observatory) to 8-10m. Commissioning and initial operation will be on the 2.7-m telescope from late 2013. The pipeline package is a part of the IGRINS software and designed to be compatible with other package that maneuvers the spectrograph during the observation. This package provides high-quality spectra with minimal human intervention and the processes of order extraction, distortion correction, and wavelength calibration can be automatically carried out using the predefined functions (e.g. echellogram mapping and 2D transform). Since the IGRINS is a prototype of the Giant Magellan Telescope Near-Infrared Spectrometer (GMTNIRS), this pipeline will be extended to the GMTNIRS software.