• 한국유체기계학회 논문집
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• 제17권6호
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• pp.109-114
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• 2014

After the Fukushima accident in 2011, it was revealed that nuclear power plant has the vulnerability to SBO accident and its extension situation without sufficient cooling of reactor core resulting core meltdown and radioactive material release even after reactor shutdown. Many safety systems had been developed like PAFS, hybrid SIT, and relocation of RPV and IRWST as a part of steps for the Fukushima accident, however, their applications have limitation in the situation that supply of feedwater into reactor is impossible due to high pressure inside reactor pressure vessel. The concept of hybrid heat pipe with control rod is introduced for breaking through the limitation. Hybrid heat pipe with control rod is the passive decay heat removal system in core, which has the abilities of reactor shutdown as control rod as well as decay heat removal as heat pipe. For evaluating the cooling performance hybrid heat pipe, a commercial CFD code, ANSYS-CFX was used. First, for validating CFD results, numerical results and experimental results with same geometry and fluid conditions were compared to a tube type heat pipe resulting in a resonable agreement between them. After that, wall temperature and thermal resistances of 2 design concepts of hybrid heat pipe were analyzed about various heat inputs. For unit length, hybrid heat pipe with a tube type of $B_4C$ pellet has a decreasing tendency of thermal resistance, on the other hand, hybrid heat pipe with an annular type $B_4C$ pellet has an increasing tendency as heat input increases.

• 영어어문교육
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• 제12권4호
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• pp.235-251
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• 2006

This study aims to analyze what Saul Bellow wants to define "Love" in his recent work, More Die of Heartbreak. As a humanist, Saul Bellow is concerned about materialism in Post-modern age through his works. Today there are so many people that are hurt by the failure of love or experience heartbreak. We need to sense invisible danger all around us. We can find Bellovian love in More Die of Heartbreak. Bellow suggests that there should be "true love" between people, especially between men and women. But Kenneth Trachtenberg and Benn Crader have selfish and materialistic love. Kenneth had only a sensual desire for Treckie who is his daughter's mother. He cannot persuade Treckie to marry him. Benn, a middle-aged widower, peremptorily marries Matilda Layamon who is much younger than he. Unfortunately, the marriage brings him neither peace nor love. Benn recognizes his wrong conception of love through the death of Mrs. Bedell and Villitzer, and breaking off a marriage with Matilda. He decides to go to Antarctica. This is not an escape. This is his determination to save himself. At the North Pole he sets out to recover his gift of vision and redeem his fall from grace. He will desert his materialistic and absurd self. After the expedition, he will experience rebirth as an authentic human being who has acceptable eyes. Kenneth and Benn learn to conceive of love as one of man's strongest inner energies, for it is through love that you can penetrate to the essence of human being. In this study I try to define Bellovian love. In More Die of Heartbreak, love is a spiritual power that may even transfigure man.

• 한국화재소방학회논문지
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• 제20권1호
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• pp.71-76
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• 2006

전기화재의 주된 원인은 단락 및 과부하 사고, 누전 및 접촉불량 등으로 구분되며, 화재의 발생요인은 이들 사고에서 동반되는 아크나 스파크로 인한 화재가 대다수이다. 저압배전선로에 사용되는 고감도형 누전차단기는 누전과 과부하를 검출하여 차단하는 기능은 있으나, 전기화재의 직접적인 위험요소인 아크나 스파크 현상에 대한 차단기능은 없는 것으로 분석된다. 이것은 저압 분전반에 적용되는 누전차단기의 경우 정격차단시간이 30[ms](KS C 4613)로 정해져 있어, 더욱 낮은 레벨로 주기적으로 발생되는 아크나 스파크를 감지하지 못하기 때문이다. 이러한 문제점을 개선하기 위하여 본 논문에서는 전기화재에 기인되는 아크나 스파크에 대해 누전차단기를 트립시키는 보조제어장치를 제안하고, 제안된 보조제어장치의 이론적 해석과 실험측정을 통해 그 타당성을 입증시킨다.

• 디지털융복합연구
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• 제9권1호
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• pp.89-106
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• 2011

With the development of the Internet, the media market is experiencing rapid change. The traditional form of offline newspaper markets, which has created the mainstream news delivery market, have been losing large amounts of power due to the emergence of online media. On the other hand, online media armed with its ability to post breaking news almost as it occurs has increased its influence and popularity at a rapid speed. However, since the exposure time and readership of online newspapers are less than their offline counterparts online media has a high dependence on sensational titles and somewhat exaggerating headlines rather than the objective and recapitulative headlines which are preferred. This paper will examine the function and significance of headlines, and conduct a comparative analysis on contents and forms of the headlines in offline newspaper and online newspaper in order to identify the characteristics of each newspaper. Through comparisons, it examines the types of headlines and the transference of headlines. In addition, it examines the differences in recognition of copy editors according to media in determining the headline, and it illuminates which type of headlines is preferred in order to instigate readers to read online newspapers. The analysis results of title-transferring cases in offline newspaper and online newspapers are that offline newspapers try to convey the contents accurately by making use of an information-transferring headline, while attention-attracting headline or subject-hiding headlines tend to be used for attracting the eye of readers. In addition, analysis results of headlines that are put on the top with a click counts in online newspapers are that attention-attracting headlines are the majority, while subject-hiding headlines that are hardly used in offline newspapers, are well-used in online newspapers. In an interview with copy editors, they responded that offline editors focus on the fact-transference in determining the title, while online editors put the weight on immediacy in the delivery of news and the function of guiding readers.

• 융합정보논문지
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• 제10권3호
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• pp.92-103
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• 2020

본 연구는 우리나라 저출생 현상의 심각성을 공감하고, 저출생 현상과 관련하여 그 원인에 대한 분석과 이에 대한 유아교육·보육정책 방안 수립에 대해 논의하고자 한다. 특히 기존의 상부하달의 하향식 유아교육·보육정책 방안 수립에서 탈피하여 유아교육·보육 관련 구성원의 목소리가 정책에 반영될 수 있게 하는 상향식 유아교육·보육정책 방안을 수립하는데 목적이 있다. 이를 위해 델파이 기법을 활용하여 연구를 수행하였고, 유아교육 및 보육 분야 전문가 20인을 전문가 패널로 구성하였다. 본 연구에서는 저출생 현상 대책을 위한 상향식 유아교육·보육정책 방안으로 '기회' 준거에 7개의 정책, '서비스' 준거에 11개의 정책, '재화/상품권/세금감면' 준거에 8개의 정책, '현금급여' 준거에 7개의 정책, '권력' 준거에 5개의 정책이 제안되었다. 본 연구에서 제안된 저출생 현상 대책을 위한 상향식 유아교육·보육정책 방안은 우리나라 저출생 현상을 해결함에 있어 구체적인 시사점이 되기를 희망한다.

• 한국안전학회지
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• 제31권3호
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• pp.16-21
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• 2016

Carbon Fiber Reinforced Plastic(CFRP) composite with a higher specific strength and rigidity is more excellent than conventional metallic materials or other organic polymer of FRP. It has been widely used in vehicles, aerospaces and high technology industries which are associated with nuclear power fields. However, CFRP laminated composite has several disadvantages as like a delamination, matrix brittleness and anisotropic fibers that are the weak points of the crack initiation. In this present work, the reinforced silicon carbide(SiC) particles were added to the interlayer of CFRP laminates in order to mitigate the physical vulnerability affecting the cracking and breaking of the matrix in the CFRP laminated composite because of excellent specific strength and thermal shock resistance characteristics of SiC. The 1wt% of SiC particles were spread into the CFRP prepreg by using a spray coating method. After that, CFRP prepregs were laminated for the specimen. Also, the twill woven type CFRP prepreg was used because it has excellent workability. Thus the mechanical and fracture behaviors of the twill woven CFRP laminated composite reinforced with SiC particles were investigated with the acoustic emission(AE) method under a fracture test. The results show that the SiC particles enhance the mechanical and fracture characteristics of the twill CFRP laminate composite.

• 한국해안·해양공학회논문집
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• 제20권1호
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• pp.101-109
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• 2008

현재까지 제안된 해빈 종단면 변형 모델은 공통적으로 폭풍으로 인한 해빈침식과 연안 사주의 형성에 대해서는 비교적 잘 모의 할 수 있었으나 폭풍 후 퇴적작용에 의한 정상 해빈으로의 복구 과정은 잘 모의하지 못하고 있다. 본 연구에서는 이와 같은 한계를 극복하고자 쇄파에 의해 부유된 모래를 천수 Dean상수를 이용해 재분배하는 메카니즘을 적용한 새로운 수치모델을 제안하였다. 수치모의 결과를 미육군공병단과 일본 중앙전력연구소에서 실시한 LWT (Large Wave Tank) 실험과 비교하여 정확성을 검증하였다.

• 전기학회논문지
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• 제62권2호
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• pp.278-283
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• 2013

With the increasing power demands, size of the fault current in electrical grids is steadily increasing, and it exceeds the breaking capacity of circuit breakers. To effectively cope with these problems, a high-speed interrupter was suggested. The high-speed interrupter provides fault current with a bypass to a fault current limiter in case of accidents and consequently, fault current can be restricted. In this study, behavioral characteristics of high-speed interrupter were analyzed by accident types occurred in a distribution system. When accidents occurred, a and b contact of the high-speed interrupter were turned-off and then, turned-on. Accordingly, fault current flowed to the circuit connected to a current limiting element, and the fault current limiter restricted fault current to within a half-cycle. Nevertheless, the behavior of the high-speed interrupter was slowed down by a switching surge. As a result, fault current was confirmed to be restricted not to within the anticipated half-cycle, but to after a half-cycle. Moreover, the behavioral characteristics of the high-speed interrupter changed not only by accident types, but by behaviors of R, S, and T phases. This was due to the errors in stroke lengths of the high-speed interrupters, which resulted in a slight time discrepancy among three interrupters. In addition, the switching behaviors of the b and a contact were confirmed not to have coincided due to the switching surge; b contact behaved first and a contact followed. because of this, accuracy of stroke length and switching surges through the solenoid suction increases may be necessary to resolve.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.489-494
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• 2004

In this paper, we investigated impurities content and thermal properties showing by changing the content of carbon black which is semiconductive materials for underground power transmission. Specimens were made of sheet form with the three of existing resins and the nine of specimens for measurement. Impurities content of specimens was measured by ICP-AES(Inductively Coupled Plasma Atomic Emission Spectrometer), and density of specimens were measured by density meter. And then heat capacity(${\Delta}H$) and melting temperature(Tm), specific heat(Cp) were measured by DSC(Differential Scanning Calorimetry). The dimension of measurement temperature was $0[^{\circ}C]\;to\;200[^{\circ}C]$, and rising temperature was $4[^{\circ}C/min]$. Impurities content was highly measured according to increasing the content of carbon black from this experimental result also density was increased according to these properties. Specially, impurities content values of the A1 and A2 of existing resins were measured more than 4000[ppm]. Heat capacity, melting temperature, and specific heat from the DSC results were simultaneously decreased according to increasing the content of carbon black. Because metallic impurities of carbon black having Fe, Co, Mn, A1 and Zn are rapidly passed kinetic energy increasing the number of times breaking during the unit time with the near particles according to increasing vibration of particles by the applied heat energy.

• 한국결정성장학회지
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• 제29권1호
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• pp.32-38
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• 2019

서비스디자인 방법론을 통해 사용 편의성에 중점을 둔 신개념의 모듈형 자전거 액세서리를 탄소 소재를 이용하여 개발하였다. 기존의 탄소 재질을 사용할 경우 자전거 주행 중 충격에 견디지 못하거나, 파손 현상이 발생하였으며, 이러한 문제점을 해결하고자 새로운 소재(S Foam Core 소재)를 적용 하였다. 기존 탄소 재질과 S Foam Core 소재의 강도, 뒤틀림 강도, 충격흡수 및 진동감쇄 측정을 하였고, S Foam Core가 적용된 제품이 기존 탄소 소재 보다 더 우수한 결과를 얻었다. 본 연구에서는 S Foam Core 소재로 프로토 타입을 제작하여, 자체 실험을 통해 검증하였고, 이를 보고하고자 한다.