• Nuclear Engineering and Technology
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• 제29권3호
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• pp.229-239
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• 1997

To investigate the realistic behavior of mass and energy release and resultant containment response during large break Loss of Coolant accident (LOCA), analyses are performed for Yonggwang (YGN) 3&4 nuclear power plants by using a merged version of RELAP5/CONTEMPT4 computer code. Comparative analyses by using conservative design computer codes are also peformed. The break types analyzed are the double-ended guillotine breaks at the cold leg and hot leg. The design analysis resulted in containment peak pressure during post-blowdown phase for the cold leg break. However, the RELAP5/CONTEMPT4 analyses show that the containment pressure has a peak during blowdown phase, thereafter it decreases monotonously without the second port-blowdown peak. For the hot leg break, revised design analysis shows much lower pressure than that reported in YGN 3&4 final safety analysis report. The RELAP5/CONTEMPT4 analysis shoos similar trend and confirmed that the bypass flow through the broken loop steam generator during post-blowdown is negligibly small compared to that of cold leg break. The low pressure and temperature predicted tv realistic analysis presented in this paper suggest that the design analysis methodology contains substantial margin and it can be improved to provide benefit in investment protection, such as, relaxing plant technical specifications and reducing containment design pressure.

• Nuclear Engineering and Technology
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• 제29권6호
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• pp.488-499
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• 1997

The measurements of the moderator temperature coefficient (MTC) are performed to demonstrate that the calculational model produces results that are consistent with the measurements. Since negative MTC is also a technical specification value that may limit the cycle length, it is important to measure it as accurately as possible. In this report, preferred choice of test method depending on the time in cycle, best power indication and temperature definition in MTC calculation were determined based on the MTC test results taken during initial startup testing and at 2/3 cycle burnup in the Yonggwang nuclear power plant. The results show that the ratio and rodded methods provided good agreement with the predictions during initial startup testing. However, near end-of-cycle the depletion method gives better results, and so is suggested to be used in the MTC measurements at 2/3 cycle burnup. The use of primary Delta T power as a power indicator in the MTC calculations is highly advisable since it responds with good consistent results very quickly to changes unlike secondary calorimetric power. For the appropriate temperature definitions used in the MTC calculations, it is considered that the arithmetic average temperature measured simply by inlet and outlet thermocouples is preferred. Although volumetric average temperature provides better results, the improvement is not sufficient to compensate for the simplicity of calculations by arithmetic average temperature.

• 전자통신동향분석
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• 제33권5호
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• pp.64-75
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• 2018

People usually check their social media, e-mail, and online news on their smartphones using their carrier network. During this process, much of the data traffic is offloaded to ubiquitous Wi-Fi networks. Such offloading will continue to increase rapidly because of flourishing public Wi-Fi networks located around the world. In this technical report, we first investigate domestic public Wi-Fi projects, and followed by foreign projects. In addition, we investigate the Wi-Fi technology evolution that has been standardized in IEEE 802. More and more people are tending to use Wi-Fi, not only at home or work, but also on public transport such as buses and trains. Hence, it is important to come up with ideas that can realize Wi-Fi onboard. The key technologies needed here are related to a mobile wireless backhaul between trains and trackside radio equipment, or between buses and roadside units. Thus, we also investigate the mobile wireless backhaul technologies and their trends.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.552-555
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• 2001

본 논문에서는 컴퓨터 및 통신분야의 급속한 기술발전으로 마이크로세서의 성능향상과 제어용 LAN(Local Area Network)이 실용화됨으로 시스템 구축에 대한 유연성이 높아져 중앙처리장치(CPU)를 기능별로 분리하고 LAN 통신선로(Dataway)를 이용하여 프로세스의 제어기능은 분산시키고, 정보처리 및 감시와 운전조작기능은 집중화시켜 전체시스템을 구성하므로 신뢰성 향상을 도모하는 분산제어시스템의 개발배경과 적용과정 그리고 제철, 전력, 환경, 수 처리, 석유화학 등의 산업현장에서 다방면에 적용 및 응용되고 있는 분산제어시스템을 고찰하여 보고 향후 분산제어시스템의 발전방향까지 살펴보았다.

• 전자공학회논문지
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• 제54권2호
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• pp.151-156
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• 2017

SCTP를 포함한 멀티미디어 통신 프로토콜에서 통신 성능에 관련된 요구 사항들은 QoS 매개 변수들로서 서술된다. QoS매개 변수들 중에서 중요한 매개 변수 중의 하나가 전송 신뢰성이다. QoS 매개 변수로서의 신뢰성은 오류 감지, 보고 그리고 정정 기법으로 정의된다. 하지만 기존의 SCTP를 포함한 멀티미디어 통신 프로토콜의 오류 제어 기법들은 멀티미디어 데이터의 통합된 관점을 고려하지 않았다. 본 논문에서는 SCTP에 멀티미디어 데이터의 통합된 오류회복 기법을 설계하고 제안하였다. 본 논문에서 제안한 기법은 사용자의 요구사항을 만족시키면서도 재전송을 위한 프레임 버퍼의 감소, 프로세싱 파워의 감소, 대역폭의 감소 등과 같은 통신자원의 효율적인 사용을 통한 효과적인 오류제어 방식이 될 것이다.

• 미생물학회지
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• 제53권1호
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• pp.64-66
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• 2017

Caballeronia sordidicola strain PAMC 26592 was isolated from Umbilicaria sp., a lichen material collected from Svalbard Archipelago in the Arctic Ocean. We report the draft genome sequence of the strain PAMC 26592, a metabolic generalist. As we have observed in previous genomic studies in the genus Caballeronia draft genomic sequences of PAMC 26592 had an assortment of genes of ecological importance and of bio-technical potentials, which include diverse metabolic genes for carbohydrates, aromatic compounds, amino acids, and vitamins, and genes for nitrogen / sulfur metabolisms, stress responses, membrane transporters, antibiotic resistance, and heavy metal resistance.

• 천문학회보
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• 제37권2호
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• pp.210.1-210.1
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• 2012

We report technique used for improved measurement uncertainties for Photon detection efficiency(PDE) of $1mm^2$ single pixel SiPM. It consists of 470nm LED light source, two 2-inch integrating sphere and two NIST calibrated silicon photodiodes that have ${\pm}2.4%$ calibration error. With raytracing simulation of our experimental setup, we predict number of photon into SiPM and measurement uncertainty. For MPPC, Hamamatsu suggested PDE(1600 micro pixel) including crosstalk and afterpulse is 23.5% at 470 nm. By using new low calibration error photodiode and raytracing simulation, our simulation result has ${\pm}3%$ measurement uncertainty. The technical detail of measurement, simulation are presented with the results and implication.

• 터널과지하공간
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• 제30권1호
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• pp.1-14
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• 2020

미소진동 모니터링은 구조물의 미세 수준의 손상을 감지하여 구조물의 성능확인 및 안전관리에 활용된다. 신뢰도 높은 미소진동 모니터링 시스템을 구성하기 위해서는 수집된 신호를 변환하는 시그널 컨디셔너의 역할이 매우 중요하다. 시그널 컨디셔너는 정확한 데이터 수집과 기기 정밀 제어에 도움을 주며 신호변환, 선형화, 증폭 등의 추가적인 기능을 수행한다. 본 기술보고는 기존에 개발한 미소진동 모니터링 시스템의 성능을 향상하여 보다 정밀한 모니터링 구현을 목적으로 광산현장에 적합한 노이즈 저감형 시그널 컨디셔너를 개발하고 이를 검토하였다.

• Journal of Chest Surgery
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• 제44권1호
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• pp.61-63
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• 2011

Implantable cardioverter defibrillator (ICD) can be a crucial therapeutic modality for pediatric patients with congenital heart disease, Brugada syndrome, long QT syndrome and cardiomyopathy. Because transvenous implantation of ICD is mostly unfeasible for pediatric patients due to anatomical and technical limitations, epicardial patch type or subcutaneous type ICD have been used. Implantation of these alternative ICDs, however, was reported to be frequently associated with significant complications. We report a case of successful intrapericardial implantation of a single coil-type ICD through the transverse sinus in a 27 month-old child weighing lesser than 10 kg, and it was inferred from this experience that this alternative technique may decrease complications and morbidities after ICD implantation in children.

• Asia pacific journal of information systems
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• 제25권1호
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• pp.143-161
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• 2015

The South Asian Association for Regional Cooperation (SAARC) nations are a potpourri of diverse religions, races and cultures with rich natural and cultural heritage but yet to tap the full potential of tourism. An investigation into the glorifying heritage of these eight SAARC nations pinpoints towards their rich food and culinary heritage that is yet to be explored to carve them as food destinations that would definitely help ameliorating tourism too. The Global Report on Food Tourism of the United Nations World Tourism Organization (UNWTO) reveals results from a survey on food tourism marketing promotion, from which internet marketing tools, such as websites have been effectively utilized to promote food tourism in a particular destination. (UNWTO, 2012). Sensing the importance of the websites in the promotion of food tourism for any destination, the present study aims at the comparative content analysis of the official tourism websites of SAARC nations to evaluate their performance from the perspective of promotion of culinary heritage on world -wide web. The modified Balanced ScoreCard (BSC) approach is incorporated into the evaluation by taking into consideration four perspectives: technical, user friendliness and site attractiveness, tourism effectiveness and food tourism effectiveness. A set of 88 critical success factors representing these four perspectives is then used to examine the websites. The study reflects on the relative strength and weakness of the tourism websites of SAARC nations in promoting food tourism and as well help suggesting the remedial measures catalyzing the food tourism promotion through websites.