• Title/Summary/Keyword: 폭발 해석

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A Study of Liquid Nitrogen Inert Gas System for LNGC Diesel Engine Crank Chamber (LNGC 디젤기관 크랭크 챔버용 액체질소 불활성가스 시스템에 관한 연구)

  • Choi, Bu-Hong;Kim, Hyun-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.3
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    • pp.279-285
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    • 2012
  • It is necessary to install the inert gas system(IGS) for preventing fire and explosion in LNGC main diesel engine crankcase besides oil mist detector(OMD) unit with $CO_2$ gas injector. Therefore, to design the liquid nitrogen IGS, analytical work is conducted for predicting the heat input load of liquid nitrogen heater with two-phase stratified flow model. This paper also presents the effects of changes in pipe diameter, saturated pressure, and inclination angle by ship's movement on cryogenic two-phase stratified flows. It is found that the stratified model gives reasonable predictions, and the model is effective to predict the heat input load of liquid nitrogen IGS.

A Study on the Improvement of Network by e-Trade (전자무역의 네트워크 개선방안에 관한 연구)

  • Jeong Boon-do
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.7
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    • pp.1548-1554
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    • 2005
  • e-Trade could improve marine logistic industry of our country to be convenient and efficient. However, in view of management, technical problems of networks have been revealed due to rapid increase of communications including electronic data. So, in order for Korea to be a leading country in east-northern Asia and a center for marine logistic information, control methods of networks should be employed effectively among information technology needed for e-Trade. Our objective to this research is focused as follows; Firstly, we investigate each part of e-Trade network and technical problems of communication networks. Secondly, we present an efficient control method of e-Trade network handling a large amount of network traffic. In this research, we try to provide an analytic foundation to practitioners rather than to present a direction to develop a new technology of communication networks.

Analysis of Ideology characteristic reflected in -With focus on Lance of Longinus and A.T Field- (<신세기 에반게리온>에서 나타난 이데올로기 특징 분석 -'롱기누스의 창'과 'AT필드'를 중심으로-)

  • Liu, Si-jie;Lee, Jong-han
    • Cartoon and Animation Studies
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    • s.47
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    • pp.149-170
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    • 2017
  • which was first shown as TV series in 1995 has been highly praised until now successful animation that reflected human psychology and ideology. first gained popularity in Japan and spreaded into global animation market. Characteristics of can be summarized as mechanical design, realistic military mise-en-scene, and philosophical view of the world based on the bible. All works reflect the philosophy and ideology of the writer/creator, but reflects various form of ideology. Furthermore, 's ambiguous and vague plot made the fans to discuss and analyze about the work, which brought secondary marketing effect. In this report, the ideology reflected in will be analyzed and understand how these ideologies were reflected in the work. By analyzing religious, psychological and philosophy ideologies in , ideology can be proved as success factor of animation films.

Spectral Analysis Method for Classification of Liquid Characteristics (액체의 특성 분류를 위한 스펙트럼 분석 방법)

  • Lee, Jonggil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.12
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    • pp.2206-2212
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    • 2016
  • It is necessary to find characteristic phenomena related with permittivity differences for classification of liquid characteristics. If these phenomena can be remotely detected and characteristics can be extracted, it will be very useful in finding flammable liquid materials and classifying substances of these liquids. Therefore, in this paper, reflection and transmitted signals were analyzed from three receiving antennas with one transmitting antenna using wideband electromagnetic wave signals. Frequency response characteristics of reflected or transmitted signals are different according to characteristics of liquid materials. However, conventional FFT methods cannot be applied due to problems of low resolution caused by data windowing distortion. To minimize these problems, eigenvector analysis method was applied for high resolution spectrum estimation of received signals. From these results, it can be shown that classification of many kinds of liquids are possible using peak frequencies and corresponding peak power values of spectrum estimates obtained from various liquid materials.

Semantic Web based DQL Search System (시멘틱 웹 기반 DQL 검색 시스템 설계)

  • Kim Je-Min;Park Young-Tack
    • The KIPS Transactions:PartB
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    • v.12B no.1 s.97
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    • pp.91-100
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    • 2005
  • It has been proposed diverse methods to use web information efficiently as the size of information is increasing. Most of search systems use a keyword-based method that mostly relies on syntactic information. They cannot utilize semantic information of documents and thus they could generate to users. To solve shortcoming in searching documents, a technique using the Semantic Web is suggested. A semantic web can find relevant information to users by employing metadata which are represented using standard ontologies. Each document is annotated with a metadata which can be reasoned by agents. In this paper, we propose a search system using semantic web technologies. Our semantic search system analyzes semantically questions that user input, and get resolution information that user want. To improve efficiency and accuracy of semantic search systems, this paper proposes DQL(DAML Query Language) engine that employs inference engine to execute reasoning and DQL converter that changes keyword form question of the user to DQL.

An Experimental Study on the Material Characteristics of Mechanical Filters for Eliminating High-Frequency Noise in Accelerometer Measurements (가속도 측정에 있어 고주파 잡음 제거를 위한 기계적 필터의 재료 특성에 관한 실험적 연구)

  • Choi, Won-Yeong;Yoo, Seong-Yeol;Cha, Ki-Up;Kim, Sung-Soo;Noh, Myoung-Gyu
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.7
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    • pp.773-778
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    • 2011
  • Accelerometers are widely used to measure the lateral vibrations of pipe-like structures such as a gun tube under impulse loads. Stress waves that precede the lateral vibrations due to the explosion within a gun contribute little to the vibrations, but saturate the accelerometer input. A mechanical filter eliminates this high-frequency stress wave and only transmits the signal corresponding to the lateral vibrations. The mechanical filter consists of a mechanical structure for mounting the accelerometers and a damping material. The low-pass filter characteristics are determined from the equivalent damping and stiffness property of this damping material. In this paper, we tested nine commercially available damping materials for their vibration characteristics by using a test rig. We also observed the change in the vibration characteristics while compressing the material. We designed and manufactured a mechanical filter and verified its filtering performance.

Quality Analysis of Web-site User Interface ; Using Kano's Two-dimensional Concept of Quality Model (웹사이트 사용자 인터페이스의 품질 분석 - Kano의 품질 인식 모형의 적용 -)

  • 김재전;이경재
    • Proceedings of the Korea Society of Information Technology Applications Conference
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    • 2002.11a
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    • pp.85-98
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    • 2002
  • 인터넷 이용의 폭발적인 증가와 함께 웹사이트에 대한 개인적ㆍ사회적 관심이 증대되고 있다. 이렇게 인터넷에 대한 대중의 관심과 참여가 늘어남에 따라 정보의 무분별한 발생을 막고 검색을 보다 효과적으로 하기 위한 사용자 인터페이스는 가치가 더욱 증대되었다. 최근에는 개별적인 연구자들뿐 아니라 웹사이트 평가기관과 순위기관들이 각각의 평가영역과 평가모형에 따라 웹사이트, 그리고 사용자 인터페이스를 평가하고 있다. 이러한 평가기준들은 웹사이트의 품질을 평가하는데 있어 주로 일원적인 인식방법을 사용하고 있다. 즉, 웹사이트 품질이나 사용자 만족을 측정하는 데 있어 품질의 고저나 만족ㆍ불만족을 일직선상에서 평가하고 있는 것이다. 다시 말하면 어떤 물리적 상황이 충족되면 사용자가 만족을 느끼지만 충족되지 않을 경우에는 불만을 가지게 된다는 가정에서 평가모형들이 개발되고 있는 것이다. 본 연구에서는 Kano의 모형에 따라 품질을 물리적 충족상황을 횡축에, 고객의 만족감을 종축에 두고 품질개념을 이원적으로 해석하여 매력적, 당연적, 일원적 품질요소로 분류하고자 하였다. 웹사이트 평가와 웹사이트 인터페이스 평가를 위한 선행연구들을 종합하여 화면구성, 항해성, 검색성, 상호작용성, 사용자지원성의 5가지 영역에서 25개의 평가항목을 추출하였으며, 이를 Kano의 설문지조사법을 이용하여 설문을 수행하였다. 게임사이트, 커뮤니티 사이트, 쇼핑몰 사이트, 일간신문 사이트를 대상으로 290부의 설문을 수거하여 분석한 결과 각각의 사이트의 인터페이스 품질요소에서 매력적 품질요소, 일원적 품질요소, 당연적 품질요소를 분류했다. 종합적으로 볼 때, 인트로나 메인페이지의 포인트, 다양한 정렬방식, 개인화된 페이지, 개인장치로의 다운로드가 매력적 품질요소로 분류되었으며, 시각적 구성, 링크의 정확성, 링크분류의 체계성, 용어의 명료성, 컨텐츠 이용의 용이성, 적절한 강조의 사용, 고객피드백시스템은 일원적 품질요소로 분류되었다. 또한 당연적 품질요소는 사이트 설계의 일관성, 에러처리, 의견제시 공간, 이용설명서 또는 도움말, FAQ로 나타났다. 이러한 연구의 결과를 통해 웹사이트를 운영하는 기업에 새로운 웹사이트의 설계 및 운영에 있어 우선순위를 부여하는 데 도움이 될 것으로 기대된다.

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Safety Assessment of By-product Gas Piping after Design Change (부생가스 연료배관의 설계변경에 따른 안전성 평가)

  • Yoon, Kee Bong;Nguyen, Van Giang;Nguyen, Tuan Son;Jeong, Seong Yong;Lee, Joo Young;Kim, Ji Yoon
    • Journal of the Korean Institute of Gas
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    • v.17 no.2
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    • pp.50-58
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    • 2013
  • Various process piping usually carries out high flammable and explosible gas under high pressure and high temperature. Due to frequent change of design and structure it becomes more complicated and compactly located. The safety management level is relatively low since it is considered as simply designed component. In this study a safety assessment procedure is proposed for complicated piping system around a mixing drum in which natural gas and by-product gases were mixed. According to ASME code, pipe stress analysis was conducted for determining design margin at some key locations of the piping. These high stress locations can be used as major inspection points for managing the pipe integrity. Sensitivity analysis with outside temperature of the pipe and support constraint condition. Possible effect of hydroen gas to the pipe steel during the previous use of the by-product gas was also discussed.

Numerical Simulation for Prediction of Existing Cavity Location on Explosion-Induced Building Collapse (폭발에 의한 건축물 붕괴 시 매몰공동 위치 예측에 관한 수치해석 사례 연구)

  • Jung, Jahe;Park, Hoon;Kim, Kwang Yeom;Shin, Hyu-Soung
    • Journal of the Korean Society of Safety
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    • v.30 no.6
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    • pp.94-101
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    • 2015
  • When a severe disaster such as a building collapse occurs, a first priority for rapid rescue is to find a location where people are highly expected to be buried but alive. It is, however, very difficult to correctly designate the location of such cavities by conventional geophysical survey due to a pile of debris of building members. In this study, location of possible lifeguard cavities were evaluated through a series of simulations of building collapse by explosion depending on the height of the building, a structure of basement floor and a location of explosion. Three types of building structure: five-story, ten-story and fifteen-story were prepared as a model for the simulation. As a results, in the case of low building, only basement floor partially collapsed. On the other hand, in the case of high building, a collapsed range on the inside of the building increased and lifeguard spaces were formed only in the lateral side or corner of the building. In addition, when a wall exists in the basement floor, the possibility that cavities could be formed increased compared to the cases without wall. However, for the fifteen-story building case, no possible lifeguard cavity was found. It is noted that for a high rise building, the height of building more affect forming of safeguard cavity than the structure of the basement floor.

Evaluation of the Shock Resistance of a Gas Turbine Package (가스터빈 패키지 내충격 성능평가에 관한 연구)

  • Kim, Jae Boo;Park, Yun Ki;Park, Min Seok;Lee, Jong Hwan;An, Sung Chan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.10
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    • pp.1005-1009
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    • 2017
  • In this study, the shock resistance of a gas turbine package subjected to a shock load caused by non-contact underwater explosion was investigated using numerical analysis. To perform shock analysis, the time-history shock load was calculated according to BV-043 (German Navy Regulation). The direct transient response analysis in the time domain for the simplified Whole Engine Model (WEM) was performed using the calculated shock load. In addition, the structural integrity of a detailed model was evaluated by considering the shock load transferred to each component. As a result, it was confirmed that the safety factor was at least 1.0 as compared with the reference stress. Finally, the structural and functional integrity of the Engine Management System (EMS) of the gas turbine package was verified through an actual shock test.