• 제목/요약/키워드: fire point

검색결과 631건 처리시간 0.03초

연속충격을 고려한 발사대 반응특성 해석 (Analysis for Response of Launcher System with Continuous Impact Load)

  • 임오강;유완석;최은호;류재봉;이창훈;김상근
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.718-723
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    • 2007
  • A three dimensional multibody modeling of a launcher system was developed and dynamic characteristics of the system was carried out. All the components were modeled as rigid bodies, All the components of system, ie; chassis, turret, cage and suspension parts, are modeled as rigid. The force interaction between the ground and tire was modeled as a point contact model. The factors were selected as cause and effect diagram of the MINITAB. To see effect of the stiffness, damping, mass at the launcher system, several cases of suspension parameters were compared and optimal values were selected. The stiffness and the damping coefficient were selected as design variables to minimize the required time for the next fire. The dynamic simulation was carried out using the ADAMS, and the MINITAB was employed for data analysis.

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식물성 절연유의 전력용 변압기 적용에 따른 문제점 고찰 및 전망 (Problem considerations and expectations in applying vegetable oil to power transformer)

  • 박현수;김지호;이향범
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2009년도 정보통신설비 학술대회
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    • pp.184-186
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    • 2009
  • In past, transformer connection study was concentrated on efficiency improvement and life time broadening. But environmental side began to become important recently. In existing, quick transaction of mineral oil used to insulation oil of transformer is possibility to be difficult and causes environmental pollution in case of was outpoured and there is worry of fire occurrence. Accordingly, nonflammable performance becomes many interest in excellent vegetable oil because ignition point is high than mineral oil and environment friendly material. But, vegetable oil is cooling of transformer and insulation problem of insulating paper for cause of insulation oil special quality. Therefore, in this paper, special quality of vegetable oil that there are being a lot of mineral oil and the latest interest examined about problem and consideration item to be solved to analyzed comparison and applies vegetable oil to transformer for electric power.

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Wavelet 변환을 이용한 고저항 지락사고 고장점 추정 (Fault Location Estimation for High Impedance Fault using Wavelet Transform)

  • 김현;김철환
    • 대한전기학회논문지:전력기술부문A
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    • 제49권8호
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    • pp.369-373
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    • 2000
  • High impedance fault(HIF) is defined as a fault that the general overcurrent relay can not detect or interrupt. Especially when HIF occurs in residential areas, energized high voltage conductor results in fire hazard, equipment damage or personal threat. This paper proposes a fault location estimation algorithm for high impedance fault using wavelet transform. The algorithm is based on the wavelet analysis of the fault voltage and current signals. The performance of the proposed algorithm is tested on a typical 154kV korean transmission line system under various fault conditions. From the tests presented in this paper it can be concluded that a fault location estimation algorithm using wavelet transform can precisely calculate the fault point for HIF.

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Mechanical Properties & Ablation Mechanism of SiC Coated Carbon/Carbon Composite by Pack-cementation Method

  • Kim, J.I.;Oh, I.S.;Joo, H.J.
    • Carbon letters
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    • 제2권1호
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    • pp.27-36
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    • 2001
  • The pack-cementation process is the method which is formed SiC coating layer to improve weak oxidation properties of CFRCs (carbon fiber-reinforced carbons). This method develops the anti-oxidation coating layer having no dimensional changes and good wetting properties. In this study to improve the oxidative resistance of the prepared 4D CFRCs, the surface of CFRCs is coated by SiC using pack cementation method. The mechanical properties of SiC-coated 4D CFRCs are measured by the 3-point bending test, and their ablation properties are investigated by the arc torch plasma test. From the results, it is found that both mechanical and ablation properties of SiC-coated 4D CFRCs are much better than bare CFRCs.

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황연해독탕가미방으로 호전시킨 중풍 환자 불면증 3예 (The Effect of Hwangyeonhaedogtang-Gamibang on Insomnia in Stroke - 3-Case Report -)

  • 류순현;양대진;조기호;김영석
    • 대한한의학회지
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    • 제22권2호
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    • pp.120-127
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    • 2001
  • Insomnia is a disorder of initiaton and maintenance of sleep that results in daytime sleepiness and dysfunction, and arises from multiple psychological, physiologic and environmental factors. A number of stroke patients suffer from insomnia classified as one of the sleep disorders associated with physical illness and on the contrary insomnia may have profound deleterious effects on the natural course of stroke. We experiened three cases of stroke patients with insomnia. In the point of Differentiation of Syndromes, these subjects were diagnosed as Excessive heat-fire syndrome of stroke and were administrated with Hwangyeonhaedog-tang Gamibang. After treatment, both sleep patterns and other accompanied symptoms improved.

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온도 상승에 따른 내부 조직 특성에 관한 실험적 연구 -석고보드를 중심으로- (An Experimental Research on the Features of Interior Materials under High Temperature - Focusing on Gypsum Boards -)

  • 김광기;박선길;김우재;임남기;송병창;정상진
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.305-310
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    • 2003
  • Recently, gypsum boards are widely used as interior finishing boards for constructions because of their features of absorbing heats and little temperature rising at the early stage of fire. Therefore, in this research, basic data were suggested to secure fireproof stability by investigating interior processing features, which change together with the backside temperature of test materials from Flash Over (within 30 minutes after firing), at which temperature reaches its highest point, to survey the features of materials due to rising temperature in the chase of gypsum boards (general and fireproof gypsum boards)

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한동석(韓東錫) 역학사상(易學思想)의 특징 (A Special Characteristics of Han Dongseok's Thought about Change(易))

  • 백유상
    • 대한한의학원전학회지
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    • 제23권1호
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    • pp.187-202
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    • 2010
  • Han Dongseok advocated his own unique viewpoint about Universal Revolution based on Jeong-yeok(正易), and newly explained Exchange between Metal and Fire[金火交易]. Although he was not a researcher that had developed Jeong-yeok(正易), he has been judged as a utilitarian that tried to apply Change theory[易學] to realistic field called Oriental Medicine. The reason that such efforts are valuable is that he extended one of cosmological theory that is to say Jeong-yeok(正易) to the exchange of human body based on space-time progress. Theoretically he proved Jeong-yeok(正易) with the thought that heaven and human beings correspond to each other, realistically he showed turning point that as a main agent in Universal revolution we can change our own lives, in "The Principles of Universal Revolution", which is his most famous work.

공기흐름을 이용한 무동력 환풍장치 개발 (Development of Ventilator without Power using Air Flow)

  • 김범석;권택주;정지현
    • 동력기계공학회지
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    • 제20권2호
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    • pp.26-31
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    • 2016
  • The studies on the efficient ventilator to reduce fire and save energy have been proceeded actively. The purpose of this paper is to design a ventilator used in residential wood stove. The ventilator consists of rotation and support part, and it is operated by natural wind without power. The shape of rotation part of the ventilator is like airfoil to reinforce pressure drop. We designed direction controller for the rotation part to track the direction of wind continuously. The rotation and support part have point-contact each other to minimize a friction. We verify the properties of the proposed ventilator though simulation and experiment. The results show the proposed ventilator can exhaust safely combustion gas of the stove more than other ventilator.

건설현장에서의 안전감시단의 효율적 활용에 관한 연구 (A study on the safety supervision team's efficient using at construction site)

  • 강용탁;김창은
    • 대한안전경영과학회지
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    • 제7권4호
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    • pp.13-25
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    • 2005
  • As there are more accidents which are more serious in construction site than other industries, it needs the safety management system to be SLIM on the same time, There are still lots of difficulties to prevent those accidents exactly, so it also needs a safety supervision team to prevent the accident, unsafe operation and condition before happening, which is also called as a Man-to-Man safety management method. The range of the job site in one personnel's management is very big and large, so it needs the personnel to keep watch the safety operation and prevent any unsafe/fire accidents. Also the personnel also should find out the unsafe points in the job site, and carefully supervise the dead angle site, then support the totally safety management POINT and realize the ZERO accident.

친환경 식물성 절연유의 유중가스 분석 (Dissolved Gas Analysis of Environment-Friendly Vegetable Insulating Oils)

  • 최순호;김관식;허창수
    • 한국전기전자재료학회논문지
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    • 제28권4호
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    • pp.238-243
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    • 2015
  • The vegetable insulating oils are substitute for the mineral oil in power transformer. Vegetable insulating oils has higher flash/fire point and biodegradability than conventional mineral oils. In this paper, we investigated the dissolved gas analysis of vegetable oils. In the experiment, I had to accelerated aging under the same conditions mineral oil and vegetable oils. Accelerated aging proceeded to about 100% of the life of oil-filled transformer. In addition, we performed gas analysis of insulating oil of accelerated aging progress. The experiment results of the five gases was measured with the exception of Hydrogen and Acetylene. The mineral oil and vegetable oils gas is generated in a similar tendency depending on the accelerated aging. As a result, vegetable oils, can be dissolved gas analysis by method such as mineral oil.