• Safety and Health at Work
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• 제11권2호
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• pp.127-135
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• 2020

A safe work environment is crucial in high-risk industries, such as construction refurbishment. Safety incidents caused by uncertainty and unexpected events in construction refurbishment systems are difficult to control using conventional safety management techniques. Resilience engineering (RE) is proposed as an alternative to traditional safety management approaches. It presents a successful safety management methodology designed to deal with uncertainty in high-risk work environments. Despite the fact that RE resides in the safety domain, there is no common set of RE indicators to measure and assess resilient in the work environment. The main aim of this research is to explore RE indicators that have been identified as important in developing and assessing the resilient work environment in high-risk industries, particularly in construction refurbishment. Indicators have been attained through a systematic literature review of research and scholarly articles published between the years 2004 and 2019. The literature review explored RE indicators in various industries. Descriptive analysis and co-occurrence-based network visualization were used for data analysis. The findings revealed 28 RE indicators in 11 different high-risk industries. The results show that the four commonly used indicators were: top-management commitment, awareness, learning, and flexibility, all of which have a strong relationship with RE. The findings of this study are useful for stakeholders when making decisions concerning the most important RE indicators in the context of their research or practice as this would avoid the ambiguity and disparity in the identification of RE indicators.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.623-627
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• 2009

Recently, we have many kinds of picture format and display, and resizing (scaling) of picture becomes important. In this processing, quality of picture depends on re-sizing method. For this, some methods to improve the PSNR have been proposed. However, subjective picture quality is more important. Especially, degradation caused by re-sizing, such as jaggy (aliasing) and ringing, should be reduced. To solve them, we have proposed the method using directional adaptive interpolation. To improve the performance of this method, we consider the shape analysis this time. In the proposed method, directional adaptive processing is applied for pure edge only. In the texture area and flat area, 8 tap re-sampling filter is used. As the results of processing, the reductions of jaggy and incorrect interpolated pixels are recognized. The subjective picture quality of proposed method is significantly better than 8-tap re-sampling which gives good PSNR.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.2043-2046
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• 2002

This paper studies on Sun interference effects or Sun outage effects on C-band satellite reception signal for THAICOM2. The THAICOM2 satellite is at 78.5 degree East 〔co-located with THAICOM3〕. The down link station was located in Khon-kaen, longitude 102.83 degree East and latitude 16.43 degree North. The antenna diameter is 4.6 meters for C-band downlink station. Total 9 times of sun interference events were occurred during summer and fall of 2001 and these about 53 minutes altogether. The Maximum CM degradation of the THAICOM2 system was around 11 dB. The Sun interference events of 53 minutes of one year are 0.0122 percents of the C-band contact time when 21 hours of contact time is used f3r broadcasting a day.

• Nuclear Engineering and Technology
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• 제42권5호
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• pp.600-607
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• 2010

Rhenium-186, having a half-life of 90.64 h, is an important radionuclide, used in metabolic radiotherapy and radio immunotherapy. $^{186}Re$ hydroxyethylidene diphosphonate (HEDP) is a new compound used for the palliation of painful skeletal metastases. Its production is achieved via charged-particle-induced reactions; the data are available in EXFOR library. For the work discussed in this paper, production of $^{186}Re$ was done via $^{nat}W(p,n)^{186}Re$ nuclear reaction. Pellets of $^{nat}W$ were used as targets and were irradiated with 15, 17.5, 20, 22.5, 25 MeV proton beams at 5 ${\mu}A$ current. The radiochemical separation was performed by the ion exchange chromatography method. The production yield achieved at 25 MeV was 1.91 $MBq{\cdot}{\mu}A^{-1}{\cdot}h^{-1}$. Excitation functions for the $^{186}Re$ radionuclide, via $^{186}W(p,n)^{186}Re$ and $^{186}W(d,2n)^{186}Re$ reactions were calculated by ALICE-ASH and TALYS-1.0 codes to validate and fit the experimental data and to obtain a recommended set of data for $^{186}W(p,n)^{186}Re$ reaction. Required thickness of the targets was obtained by SRIM code for each reaction.

• 한국멀티미디어학회논문지
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• 제23권8호
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• pp.891-902
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• 2020

The Re-Identification(Re-ID) is one of the most popular researches in the field of computer vision due to a variety of applications. To achieve a high-level re-identification performance, recently other methods have developed the deep learning based networks that are specialized for only person or vehicle. However, most of the current methods are difficult to be used in real-world applications that require re-identification of both person and vehicle at the same time. To overcome this limitation, this paper proposes a deep neural network learning method that combines triplet and softmax loss to improve performance and re-identify people and vehicles simultaneously. It's possible to learn the detailed difference between the identities(IDs) by combining the softmax loss with the triplet loss. In addition, weights are devised to avoid bias in one-side loss when combining. We used Market-1501 and DukeMTMC-reID datasets, which are frequently used to evaluate person re-identification experiments. Moreover, the vehicle re-identification experiment was evaluated by using VeRi-776 and VehicleID datasets. Since the proposed method does not designed for a neural network specialized for a specific object, it can re-identify simultaneously both person and vehicle. To demonstrate this, an experiment was performed by using a person and vehicle re-identification dataset together.

• 한국세라믹학회지
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• 제39권12호
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• pp.1128-1132
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• 2002

MFS-FET(Metal-Ferroelectric-Semiconductor Field Effect Transistor) 구조의 비휘발성 기억소자용 $ReMnO_3$(Re:Y, Ho, Er) 박막을 금속 유기 화학 기상 증착법(MOCVD)으로 증착하였다. $ReMnO_3$ 박막을 Si(100) 기판 위에 700${\circ}C$-2시간 증착 시켜 결정화를 위해 대기 중에서 900${\circ}C$-1시간 열처리 시 육방정계(hexagonal) 단일상의 $ReMnO_3$ 박막을 형성하였다. 육방정계 단일상 구조에서 $ReMnO_3$ 박막의 강유전 특성은 c-축 배향성에 의존하였으며, c-축 배향성이 우수한 $YMnO_3$ 박막의 잔류 분극(Pr) 값은 105 nC/$cm^2$로 가장 우수하였다. 또한 누설 전류 밀도(leakage current density) 값은 미세구조의 결정립 크기에 의존하였으며, 결정립 크기가 100∼150 nm인 $YMnO_3$ 박막의 누설 전류 밀도 값은 인가전압 0.5 V에서 $10^{-8}$ A/$cm^2$을 나타내었다.

• 한국결정성장학회지
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• 제26권1호
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• pp.1-7
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• 2016

RE : YAG 단결정은 레이저 발진 소재로 다양한 성장 변수를 제어하면서 Czochralski법으로 성장된다. 성장과정 동안 고액계면의 온도구배 및 회전속도에 의해 발생하는 결함들은 결정의 광학적 특성 저하로 작용하기 때문에 결함 분석을 통한 결정 품질의 향상을 필요로 한다. 격자결함 밀도 분석(EPD)을 통하여 성장된 RE : YAG 단결정의 표면 결함 존재를 확인하였고, 이를 통해 투과전자현미경(TEM) 분석영역을 선택하였다. 선택한 영역의 시편은 트라이포드 연마 방법으로 제작하였고, 200 kV 투과전자현미경과 300 kV 전계 방사형 투과전자현미경(FE-TEM)을 사용하여 buckling, rod shaped, 내부응력에 의한 bend contours, 편석 등의 결함들을 관찰하였다.

• KSBB Journal
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• 제21권5호
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• pp.371-375
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• 2006

본 실험의 목적은 frontal analysis(FA)와 pluse input method(PIM) 방법으로 흡착분리공정에 있어서 중요한 전 단계의 하나인 등온흡착식을 결정하는데 있다. FA를 수행하기에 앞서 대상물질이었던 loxoprofen의 용해도를 측정하여 hexane/ethanol=95/5일 때 시료의 농도를 $0.2{\sim}3mg/ml$로 결정하고, pH조정을 위한 acetic acid는 0.5%로 결정하였다. 이동상의 주성분인 hexane의 조성이 증가함에 따라 용해도는 감소하였지만 분리도는 증가하는 경향을 확인하였다. 이런 용해도와 분리도 사이의 trade-off 또한 흡착분리과정에서의 조작변수가 될 수 있음을 의미한다. FA로 구한 이성분계 등온흡착식은 $$C_{S,re}=\frac{5.282C_{M,re}}{1+0.1412C_{M,re}+0.2139C_{M,ex}}$$, $$C_{S,ex}=\frac{6.413C_{M,ex}}{1+0.2139C_{M,ex}+0.1412C_{M,re}}$$로 결정하였고, PIM으로 구한 이성분계 등온흡착식은 $$C_{S,re}=\frac{5.245C_{M,re}}{1+0.1667C_{M,re}+0.2054C_{M,ex}}$$, $$C_{S,ex}=\frac{6.061C_{M,ex}}{1+0.2054C_{M,ex}+0.1667C_{M,re}}$$로 결정 하였다.

• 한국재료학회지
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• 제26권12호
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• pp.751-756
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• 2016

Graphite was diffusion-bonded by hot-pressing to W-25Re alloy using a Ti interlayer. For the joining, a uniaxial pressure of 25 MPa was applied at $1600^{\circ}C$ for 2 hrs in an argon atmosphere with a heating rate of $10^{\circ}C\;min^{-1}$. The interfacial microstructure and elemental distribution of the W-25Re/Ti/Graphite joints were analyzed by scanning electron microscopy (SEM). Hot-pressed joints appeared to form a stable interlayer without any micro-cracking, pores, or defects. To investigate the high-temperature stability of the W-25Re/Ti/Graphite joint, an oxy-acetylene torch test was conducted for 30 seconds with oxygen and acetylene at a 1.3:1 ratio. Cross-sectional analysis of the joint was performed to compare the thickness of the oxide layer and its chemical composition. The thickness of W-25Re changed from 250 to $20{\mu}m$. In the elemental analysis, a high fraction of rhenium was detected at the surface oxidation layer of W-25Re, while the W-25Re matrix was found to maintain the initial weight ratio. Tungsten was first reacted with oxygen at a torch temperature over $2500^{\circ}C$ to form a tungsten oxide layer on the surface of W-25Re. Then, the remaining rhenium was subsequently reacted with oxygen to form rhenium oxide. The interfacial microstructure of the Ti-containing interlayer was stable after the torch test at a temperature over $2500^{\circ}C$.

• 콘크리트학회논문집
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• 제15권6호
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• pp.811-819
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• 2003

철근의 부식은 철근콘크리트 구조물의 주요파괴 원인이다. 철근의 부식에 대한 문제점을 해결할 가능성이 있는 재료 중 FRP 보강근은 그 가능성이 높다. 그렇지만 FRP 보강근은 보강철근과 다른 파괴 매카니즘으로 의하여 현저하게 성능이 저하될 가능성을 가지고 있다. 이와 같은 환경에는 알칼리, 산, 염해 및 물과 수분 등이 있다. 따라서 본 연구에서는 FRP 보강근의 화학적 환경하에서의 내구성능을 평가하고자 하였으며 사용된 FRP 보강근은 2가지 종류의 CFRP 보강근 및 GFRP 보강근, 한가지 종류의 AFRP 보강근으로 알칼리용액, 산용액, 염해환경 및 중성용액에 노출시켰다. FRP 보강근의 역학적 특성 및 내구특성은 인장, 압축 및 전단시험을 통하여 평가하였으며 시험결과 FRP 보강근은 매우 혹독한 화학적 환경에서 우수한 내구성을 가지고 있음을 알 수 있었다.