• Title/Summary/Keyword: 구조적 붕괴

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Analysis of the Thermal and Structural Stability for the CANDU Spent Fuel Disposal Canister (CANDU 처분용기의 열적-구조적 안정성 평가)

  • Lee, Jong-Youl;Cho, Dong-Geun;Kim, Seong-Gi;Choi, Heui-Joo;Lee, Yang
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.6 no.3
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    • pp.217-224
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    • 2008
  • In deep geological disposal system, the integrity of a disposal canister having spent fuels is very important factor to assure the safety of the repository system. This disposal canister is one element of the engineered barriers to isolate and to delay the radioactivity release from human beings and the environment for a long time so that the toxicity does not affect the environment. The main requirement in designing the deep geological disposal system is to keep the buffer temperature below 100$^{\circ}C$ by the decay heat from the spent fuels in the canister in order to maintain the integrity of the buffer material. Also, the disposal canister can endure the hydraulic pressure in the depth of 500 m and the swelling pressure of the bentonite as a buffer. In this study, new concept of the disposal canister for the CANDU spent fuels which were considered to be disposed without any treatment was developed and the thermal stability and the structural integrity of the canister were analysed. The result of the thermal analysis showed that the temperature of the buffer was 88.9$^{\circ}C$ when 37 years have passed after emplacement of the canister and the spacings of the disposal tunnel and the deposition holes were 40 m and 3 m, respectively. In the case of structural analysis, the result showed that the safety factors of the normal and the extreme environment were 2.9 and 1.33, respectively. So, these results reveal that the canister meets the thermal and the structural requirements in the deep geological disposal system.

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A Study on the Perception of Orient in Huangseong-Shinmun(皇城新聞) (황성신문의 '동양(東洋)' 인식에 관한 연구)

  • Park, Jeoung-sim
    • The Journal of Korean Philosophical History
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    • no.59
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    • pp.425-453
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    • 2018
  • This paper study about the Perception of Orient in Huangseong-Shinmun(皇城新聞). The Orient as a Non-Western is recognized as a geographical concept which represented Japanized culture and which breaked up Sinocentrism. Huangseong-Shinmun thought Korea, China, and Japan as the main countries which constitute Orient. And this paper regarded these three countries which is Yellow race are main area which countervail Western. Especially this paper thought Japan as the leading power which fulfilled Oriental peace. So Huangseong-Shinmun theorized nations of the same race, region and language(同種同州同文論). But Orientalism is just means which Japan used to rationalized the imperialistic invasion. Nevertheless Huangseong-Shinmun thought that periods are the era of racial competition. This is the limit Huangseong-Shinmun did'nt recognize the strategy which Japan concealed the imperialistic invasion.

A Study on Effects of Characteristics of Internet Shopping Mall on Customer Loyalty (인터넷쇼핑몰의 특성이 고객충성도에 미치는 영향에 관한 연구)

  • Choi Seung-Il
    • The Journal of the Korea Contents Association
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    • v.5 no.4
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    • pp.45-53
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    • 2005
  • The rapid diffusion of using internet and technical development becomes a driving force creating and developing the industries based on internet and made up an electronic commerce market which is a new form of business market. The object of this study is the business form between the consumer and the enterprise having a rapid growth nowadays. We classified enterprises' characteristic factors in internet shopping mall into product's characteristic factors on shopping mall, characteristic factors of the system on shopping mall and characteristic factors of the interaction between customers and shopping mall in the internet shopping mall. And then we investigated how these classified characteristic factors on shopping mall could influence on customer loyalty.

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Natural Convection Heat Transfer in a Hemispherical Pool with Volumetric Heat Sources (체적 열원이 내재된 반구에서의 자연대류 열전달)

  • Park, Hae-Kyun;Chung, Bum-Jin
    • Journal of Energy Engineering
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    • v.24 no.3
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    • pp.135-141
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    • 2015
  • The core melts stratifies into lower mixture layer and upper metal layer by density in a severe accident condition. The decay heat generated from the mixture layer threatens the integrity of the reactor vessel. This study simulated the natural convection heat transfer of the mixture layer with volumetric heat source using the mass transfer system. $H_2SO_4-CuSO_4$ electroplating system was used as the mass transfer system. With the modified Rayleigh number of $3{\times}10^{14}$, the Nusselt number showed minimum at the bottom and increased along curvature to the top of the experimental apparatus.

Rheological Characteristics of Germinated Corn Starch (발아 옥수수 전분의 리올로지 특성)

  • Yang, Young-Kook;Lee, Shin-Young;Choi, Kook-Chi
    • Applied Biological Chemistry
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    • v.29 no.4
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    • pp.339-345
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    • 1986
  • Rheological characteristics of starch isolated from germinated corn were investigated and compared with those of nongerminated corn starch. Flow behavior of both starches were Bingham psudoplastic. Consistency index and yield stress of germinated starch solution were lower than those of nongerminated starch solution, while flow behavior index was nearly similar. Concentration dependency of both starch solutions were similar to each other but lower temperature dependency of germinated starch solution was observed. Time dependent characteristics of both starches showed thixotropic behavior, but due to germination, germinated starch showed higher structural decay under shear than nongerminated starch and its elastic properties was weaker.

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Electron Microscopic Study on Detoxication Effect of Red Ginseng Extract on Mouse Liver Injury induced by Methyl Mercury (메틸수은(水銀)으로 손상(損傷)된 생쥐 간장(肝臟)에 대한 홍삼(紅蔘) 추출물(抽出物)의 해독효과에 관한 전자현미경적(電子顯微鏡的) 연구(硏究))

  • Chung, Hee-Won
    • Applied Microscopy
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    • v.17 no.1
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    • pp.76-82
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    • 1987
  • Detoxication effect of red ginseng extract against toxicity of methly mercury on ultrastructure of mouse liver was studied by electron microscopy. The hepatocyte of methyl mercury treatment group showed partial rupture of nucleus, mitochondrial swelling, decrease of glycogen content, and appearance of a great number of large vacuoles. While, the hepatocyte of methyl mercury-red ginseng extract treatment group showed slight mitochondrial swelling and decrease of vacuoles in size and number than those of methyl mercury treatment group.

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Snow Vulnerability Analysis and Countermeasures in Jeolla-do, South Korea using Entropy Method (엔트로피 방법을 이용한 전라도지역 대설 취약성 분석 및 대응방안)

  • Ha, Joon Hyeok;Chung, Gun Hui
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.398-398
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    • 2019
  • 최근 전 세계적으로 기상이변 현상이 과거에 비해 빈번하게 발생하고 있으며, 자연재해에 의한 피해도 증가하고 있다. 한국에서 주로 발생하는 자연재해로는 호우, 태풍, 대설 등이 있고 최근 10년(2008~2017) 동안 자연재해 피해액 약 3.4조 중 대설에 의한 피해액은 약 2,200억원으로 전체 자연재해 피해액 중 약 15%를 차지하고 있다. 과거 2014년 경주 리조트에서 폭설로 인해 지붕이 붕괴되어 10명이 사망하고 100여명이 부상당하는 사건이 발생하였고, 2018년 제주도 농가지역의 시설물 및 재배작물이 수십억의 피해를 입게 되는 등 대설로 인한 큰 피해를 입는 사례들이 나타나게 되어 대설피해에 대한 관심이 높아지고 있는 추세이며 겨울철 주요 자연재해 중 하나로 인식되고 있다. 본 연구에서는 취약성 분석을 위해 PSR구조인 압력지수(Pressure), 상태지수(State), 대응지수(Response)로 인자들을 나누고 엔트로피 방법을 이용하여 전라도 지역 41개 시군구를 대상으로 가중치를 산정하였으며 이에 따른 결과 값들로 전라도 지역 41개 시군구에 대한 취약성 분석을 실시하였다. 그 결과 대설에 취약한 지역들을 순위로 도출해낼 수 있었다. 본 연구에서 도출해낸 결과를 바탕으로 하여 대설에 가장 취약한 지역들을 중심으로 대응 방안을 마련하여 대설에 대비한다면 효과적인 도움을 줄 수 있을 것으로 판단된다.

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Structure Analysis and Scale Model Test for Strength Performance Evaluation of Submersible Mooring Pulley Installed on Floating Offshore Wind Turbine (부유식 해상풍력발전기용 반잠수식 계류 풀리의 강도 성능평가를 위한 구조해석과 축소 모형시험)

  • Chang-Yong Song
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.5
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    • pp.479-487
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    • 2023
  • Recently, the destructive power of typhoons is continuously increasing owing to global warming. In a situation where the installation of floating wind turbines is increasing worldwide, concerns about the huge loss and collapse of floating offshore wind turbines owing to strong typhoons are deepening. A new type of disconnectable mooring system must be developed for the safe operation of floating offshore wind turbines. A new submersible mooring pulley considered in this study is devised to more easily attach or detach the floating of shore wind turbine with mooring lines compared with other disconnectable mooring apparatuses. To investigate the structural safety of the initial design of submersible mooring pulley that can be applied to an 8MW-class floating type offshore wind turbine, scale-down structural models were developed using a 3-D printer and structural tests were performed on the models. For the structural tests of the scale-down models, tensile specimens of acrylonitrile butadiene styrene material that was used in the 3-D printing were prepared, and the material properties were evaluated by conducting the tensile tests. The finite element analysis (FEA) of submersible mooring pulley was performed by applying the material properties obtained from the tensile tests and the same load and boundary conditions as in the scale-down model structural tests. Through the FEA, the structural weak parts on the submersible mooring pulley were reviewed. The structural model tests were conducted considering the main load conditions of submersible mooring pulley, and the FEA and test results were compared for the locations that exceeded the maximum tensile stress of the material. The results of the FEA and structural model tests indicated that the connection structure of the body and the wheel was weak in operating conditions and that of the body and the chain stopper was weak in mooring conditions. The results of this study enabled to experimentally verify the structural safety of the initial design of submersible mooring pulley. The study results can be usefully used to improve the structural strength of submersible mooring pulley in a detailed design stage.

IT Korea 성공을 위한 R&D방향

  • Kim, Heung-Nam
    • Information and Communications Magazine
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    • v.28 no.1
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    • pp.22-28
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    • 2010
  • 외환위기 이후 IT는 우리 경제의 견인차로 인식되어 왔으나 2000년대 초두의 IT 버블 붕괴 이후 극심한 성장정체를 겪으면서 일부 학자 및 정책입안자를 중심으로 IT 역할에 대한 회의론적 시각이 제기되어 왔다. 그러나, 지난 2~3년간의 각종 경제지표를 볼 때, IT는 여전히 우리 경제에서 중요한 역할을 하고 있음을 확인할 수 있을 뿐만 아니라 미래사회에의 대응을 위해서도 IT에 대한 관심 제고가 무엇보다도 절실한 시점이라 하겠다. 특히, 스마트폰의 등장에 따라 스마트폰 환경에 최적화된 다양한 애플리케이션의 등장과 이를 이용한 모바일 서비스의 보급 확산으로 IT 기기 및 서비스 산업의 경쟁구조에 근본적인 변화가 발생하면서 IT 강국이라는 국가적 브랜드마저 위협받고 있는 시점이어서 더욱 그렇다. 스마트폰의 등장으로 국가경쟁력 결정 패턴이 노동과 자본 등 전통적인 생산요소에 기반한 개별 산업분야의 경쟁우위를 기초로 결정되던 형태에서 감성과 창의성 등 소프트 파워의 보유 정도에 따라 결정되는 형태로 전환되었다는 점에서 R&D전략에 있어서도 중요한 전환점을 맞고 있다고 보여진다. 또한, 산업사회와 정보사회에 이어 급격한 기술혁신에 따른 기술간 및 산업간 융합의 정도가 산업 전반의 경쟁구도에 영향을 미칠 것으로 대부분의 전문가들이 예견하고 있으나, 산업현장이나 기술분야에서 실제적으로 발생되는 융합의 양상은 그다지 신속하지 못한 것으로 나타나고 있다. 따라서, 기술간 및 산업간 융합촉진을 통한 전산업 경쟁력 제고를 위한 R&D 방향 모색이 필요한 시점이다. 이에 따라 본고에서는 스마트폰의 등장에 따른 IT산업의 경쟁구도 변화와 글로벌 기업들의 전략, 대응방향 등을 살펴보는 한편 IT의 전반적인 활용도 증가에 따라 더욱 가속화될 것으로 전망되는 기술간 및 산업간 융합시대에 대응한 IT R&D 방향을 살펴본다. 이는 궁극적으로 IT 강국이라는 국가적 브랜드 이미지의 고착화 전략인 동시에 IT 기반의 융합을 촉진시킴으로써 스마트한 IT Korea라는 국가적 미래비전을 달성해 나가기 위한 방향이 될 것이다.

Validation of the Korean Version of the Posttraumatic Growth Inventory-Expanded (외상 후 성장 척도 확장판(The Posttraumatic Growth Inventory-Expanded: PTGI-X)의 한국판 타당화 연구)

  • Kim, Si Hyeong;Lim, Sujeong;Shin, Jiyoung;Lee, Deok Hee;Lee, Dong Hun
    • Korean Journal of Culture and Social Issue
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    • v.26 no.3
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    • pp.195-220
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    • 2020
  • The purpose of this study was to validate the Korean version of the post-traumatic growth inventory-expanded(K-PTGI-X), which has been widely used to assess posttraumatic growth. The PTGI-X is a measure of the addition of the items to measure the existential growth as the need for modification to the factors of the 'increase of spiritual interest' in the existing PTGI is suggested. We examined the factor structure, reliability, and validity of a Korean version of the PTGI-X among 625 Korean adults who have experienced trauma events. First, EFA confirmed the appropriate PTGI-X factor structure and found that the 4-factor structure was the most appropriate. Next, as a result of CFA, it was found that the model to which correlation between items was added to the 4-factor model was good. Next, testing internal consistency, CR, and AVE of the K-PTGI-X showed that PTGI-X's items are reliable. Also, we tested the concurrent validity and discriminative validity. All of the K-PTGI-X scales significantly correlated with measures of deliberate rumination and core-belief except for the intrusive rumination. Finally, to add an understanding of K-PTGI-X, t-test according to demographic variables was conducted. Recommendations for future research and implications were discussed.