• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.33-43
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• 2019

A comparison between sea trial measurements and full-scale CFD results is presented for two self-propelled ships. Two ships considered in the present study are: a general cargo carrier at Froude number $F_n=0:182$ and a car carrier at $F_n=0:254$. For the general cargo carrier, the propeller rotation rate is fixed and the achieved speed and trim are compared to sea trials, while for the car carrier, the propeller rotation rate is adjusted to achieve the 80% MCR. In addition, three grids are used for each ship in order to assess the grid refinement sensitivity. All simulations are performed using the Naval Hydro pack based on foam-extend, a community driven fork of the OpenFOAM software. The results demonstrate the possibility of using high-fidelity numerical methods to directly calculate ship scale flow characteristics, including the effects of free surface, non-linearity, turbulence and the interaction between propeller, hull and the flow field.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.184-198
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• 2020

Decisions of the design speed, MCR, and engine capacity have been empirically made by assuming the value termed the sea margin. Due to ambiguity regarding the effect of some factors on the sea margin, the value has been commonly decided based on experience. To evaluate the value from a new viewpoint, it is necessary to construct an approach to estimate the sea margin through an objective procedure based on a physical and mathematical model. In this paper, a framework to estimate the actual sea margin of an LNGC based on the maneuvering equations of motion is suggested by considering the hull, propeller, rudder, and given sea route under wind and waves. The fouling effect is additionally quantified as the increase of total resistance by considering the re-docking period. The operation data is reviewed to amend the increase of the total resistance considering the speed loss of a ship. Finally, the factor of how much the resistance increases due to fouling is newly obtained for the vessel. Based on the comparison of the estimated sea margin with the empirical range of the sea margin, the constructed framework is regarded as feasible.

• Journal of Dairy Science and Biotechnology
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• 제39권1호
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• pp.1-8
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• 2021

The surroundings of livestock farms, including dairy farms, are known to be a major source of development and transmission of antibiotic-resistant bacteria. To control antibioticresistant bacteria in the livestock breeding environment, farms have installed livestock wastewater treatment facilities to treat wastewater before discharging the final effluent in nearby rivers or streams. These facilities have been known to serve as hotspots for inter-bacterial antibiotic-resistance gene transfer and extensively antibiotic-resistant bacteria, owing to the accumulation of various antibiotic-resistant bacteria from the livestock breeding environment. This review discusses antibiotic usage in livestock farming, including dairy farms, livestock wastewater treatment plants as hotspots for antibiotic resistant bacteria, and nonenteric gram-negative bacteria from wastewater treatment plants, and previous findings in literature.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2011-2022
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• 2022

According to the defense-in-depth concept, not only a preventive strategy but also an integrated cyberattack response strategy for NPPs should be established. However, there are limitations in terms of responding to penetrations, and the existing EOPs are insufficient for responding to intentional disruptions. In this study, we focus on manipulative attacks on process data. Based on an analysis of the related attack vectors and possible attack scenarios, we adopt the Kalman filter to detect process anomalies that can be caused by manipulations of process data. To compensate for these manipulations and secure MCR operators' situational awareness, we modify the Kalman filter such that it can filter out the effects of the manipulations adaptively. A case study was conducted using a hardware-in-the-loop system. The results indicated that the developed method can be used to verify whether the displayed safety-related state data are reliable and to implement the required safety response actions.

• 대한화학회지
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• 제66권3호
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• pp.194-201
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• 2022

A simple, efficient, and cost-effective method has been employed for the synthesis of 2,4,5-trisubstituted imidazole derivatives (3a-j) containing quinoline substituent at 2^nd position. Title compounds were obtained by multicomponent reaction (MCR), involving aryl substituted 1,2-diketone, quinoline carbaldehyde and ammonium acetate in the presence of acetic acid solvent under mild reaction conditions. The newly synthesized quinoline containing imidazole derivatives were confirmed through FT-IR, ¹H-NMR, ¹³C-NMR and mass spectral analysis. In-vitro microplate alamar blue assay (MABA) to determine the MIC (minimum inhibitory concentration) values against Mycobacterium tuberculosis H37Rv was performed for the synthesized compounds. The synthesized compounds exhibited activity against Mycobacterium tuberculosis and among which compounds, 3d, 3f and 3i showed good activity. The highest activity was showed with compound 3i. The anti-mycobacterial activity results are well correlated with the computational molecular docking analysis, which was performed for the synthesized compounds prior to the evaluation of the activity.

• 아태비즈니스연구
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• 제13권3호
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• pp.119-134
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• 2022

Purpose - The purpose of this study was to expound the packaging framework system(PFS) under international trade rules. Design/methodology/approach - This study analyzed packaging framework system and packaging regulations and technical standards in international regulations and major countries and classified these in some standards Findings - First, the study provides packaging provisions associated with packaging regulations and technical standards (PRTS). Then, the basis of PFS in international trade rules was proposed; it is believed that the PFS was composed of packaging legal system in WTO institutional framework (WTO-PLS), international organization packaging standard system (IO-PSS) and major countries or regions packaging regulatory system (MCR-PRS). Secondly, this paper expounded relations and legal characteristics of the three packaging systems. Finally, This study investigated PRTS coverage under technical barriers to trade (TBT) and Sanitary and Phytosanitary measures (SPS). Research implications or Originality - The regulations associated with PRTS have played a key role in challenges to merchandise trade in international trade. This study has significance in classifying packaging related reticulations into several criteria unlike previous studies. Therefore it is hope that this study can provide a supplementary document for the existing research of PRTS.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.902-907
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• 2023

To understand the eutectic reaction mechanism and the relocation behavior of the core debris is indispensable for the safety assessment of core disruptive accidents (CDAs) in sodium-cooled fast reactors (SFRs). This paper addresses reaction products and their distribution of the eutectic melting/solidifying reaction of boron carbide (B₄C) and stainless-steel (SS). The influence of the existence of carbon on the B₄C-SS eutectic reaction was investigated by comparing the iron boride (FeB)-SS reaction by Raman spectroscopy with Multivariate Curve Resolution (MCR) analysis. The scanning electron microscopy with dispersive X-ray spectrometer was also used to investigate the elemental information of the pure metals such as Cr, Ni, and Fe. In the B₄C-SS samples, a new layer was formed between B₄C/SS interface, and the layer was confirmed that the formed layer corresponded to amorphous carbon (graphite) or FeB or Fe₂B. In contrast, a new layer was not clearly formed between FeB and SS interface in the FeB-SS samples. All samples observed the Cr-rich domain and Fe and Ni-rich domain after the reaction. These domains might be formed during the solidifying process.

• 한국안전학회지
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• 제38권6호
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• pp.72-78
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• 2023

The purpose of this paper is to derive a quantified approach for Operator Manual Actions (OMAs) based on the existing fire Human Reliability Analysis (HRA) methodology developed by the Korea Atomic Energy Research Institute (KAERI). The existing fire HRA method was reviewed, and supplementary considerations for OMA quantification were established through a comparative analysis with NUREG-1852 criteria and the review of the existing literature. The OMA quantification approach involves a timeline that considers the occurrence of Multiple Spurious Operations (MSOs) during a Main Control Room Abandonment (MCRA) determination and movement towards the Remote Shutdown Panel (RSP) in the event of a Main Control Room (MCR) fire. The derived failure probability of an OMA from the approach proposed in this paper is expected to enhance the understanding of its reliability. Therefore, it allows moving beyond the deterministic classification of "reliable" or "unreliable" in NUREG-1852. Also, in the event of a nuclear power plant fire where multiple OMAs are required within a critical time range, it is anticipated that the OMA failure probability could serve as a criterion for prioritizing OMAs and determining their order of importance.

• 한국안전학회지
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• 제29권6호
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• pp.166-171
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• 2014

Nuclear power plants are equipped with the reactor trip system (RTS) and the engineered safety features actuation system (ESFAS) to improve safety on the normal operation. In the event of the design basis accident (DBA), a various of post accident monitor(PAM)systems support to provide important details (e.g. Containment pressure, temperature and pressure of reactor cooling system and core exit temperature) to determine action of main control room (MCR). Operator should be immediately activated for the accident mitigation with the information. Especially, core exit temperature is a critical parameter because the operating mode converts from normal mode to emergency mode when the temperature of core exit reaches $649^{\circ}C$. In this study, uncertainty which was caused by exterior environment, characteristic of thermocouple/connector and accuracy of calibrator/indicator was evaluated in accordance with ANSI-ISA 67.04. The square root of the sum of square (SRSS) methodology for combining uncertainty terms that are random and independent was used in the synthesis. Every uncertainty that may exist in the hardware which is used to measure the core exit temperature was conservatively applied and the associative relation between the elements of uncertainty was considered simultaneously. As a result of uncertainty evaluation, the channel statistical allowance (CSA) of single channel of core exit temperature was +1.042%Span. The range of uncertainty, -0.35%Span ($-4.05^{\circ}C$) ~ +2.08%Span($24.25^{\circ}C$), was obtained as the operating criteria of core exit temperature.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.57-57
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• 2001

Erythropoietin(EPO)는 혈액의 구성성분 중에서 적혈구 세포 증식에 중요한 기능을 한다고 알려져 있으며, 최근에는 암, 에이즈의 치료 등에도 효과가 있는 것으로 확인되고 있다. 따라서 본 연구팀은 지금까지 hEPO 유전자를 이용하여, 형질전환 돼지 "새롬이"의 생산에 성공한바 있다. 새롬이의 정액을 활용하여 인공수정을 실시 새롬이의 Fl를 24두 생산하였다. 이에 대하여 "형질전환 돼지의 계대번식시 유전자 전이효율에 관한 연구"라는 제목으로 발표 할 예정이며, 형질전환에 사용된 promoter가 WAP이므로, Fl이 임신, 분만을 하여야만 유즙을 통하여 hEPO물질을 생산할 수 있다. 따라서, Fl(♂)$\times$Fl(♀)의 교배에 의하여 5두가 임신, 분만을 하였으며, 이들 중 1두는 분만 후 21일에 폐사하였으며, 나머지는 현재 정상적으로 사육되고 있다. 이들 5두에 대하여 분만 후 유즙을 채취하여 유즙속에 EPO의 발현여부를 검토하였다. EPO-ELISA kit(medac)를 사용하여 분석결과, 유즙을 8,000배로 희석을 하여야만 Standard curve(1.25~160 mIU/$m\ell$)안에서 EPO의 단백질 발현을 검출할 수 있었다. 5두의 각각 농도는 28, 58, 17, 37, 27 IU/${\mu}\ell$ 였다. 또한 cDNA EPO와 genome EPO를 CHO 동물세포에서 생산하여 10배로 농축한 결과 5.5와 11 IU/${\mu}\ell$의 농도로 유즙과 비교하면 약 20~30배의 낮은 발현양을 나타내었으며, 또한 이러한 결과는 소변에서의 결과(1.1 IU/$m\ell$)보다는 약 30,000배 이상 높은 발현량을 화인 할 수 있었다. 현재, 이들 유즙 물질을 활용 빈혈 질환실험동물을 이용하여 생리활성을 검정, 체내에서 metabolic clearance rate(MCR)를 검토 중에 있다. 또한 F2의 자돈생산은 모돈 5두에서 총 25두가 생산되었는데, 이중 20두 약 80%가 EPO 유전자의 전환율을 나타내었다. 이상을 종합하면, 1) 돼지이용 생리활성물질(EPO)을 유즙에서 대량으로 생산할 수 있는 system의 활용가능성을 국내에서 처음으로 확인하였으며, 2) EPO에 있어서는 국제적으로도 형질전환 가축생산은 최초로 성공하였으며, 현재로서는 생산되어진 물질의 정제수준에 따라 활용가치가 결정되어 질 것으로 사료된다. 생리활성 물질을 생산할 수 있는 형질전환 돼지 생산의 성공은, 앞으로 형질전환 가축생산 뿐 만 아니라, 장기이식 및 복제돼지 생산의 활용 면에서의 응용가능성이 기대된다.