• 제목/요약/키워드: Supply Leading Time

검색결과 54건 처리시간 0.024초

액체 로켓 엔진에 있어서 추진제 공급 선점 시간에 따른 점화 특성에 관한 연구 (A Study on Ignition Characteristic with Supply Leading Time of Propellants in Liquid Rocket Engine)

  • 박정;김용욱;김영한;이재룡;정용갑;조남경;오승협
    • 대한기계학회논문집B
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    • 제24권11호
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    • pp.1457-1463
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    • 2000
  • Experimental studies on determination of the supply leading time of propellants to combustion chamber have been made to stably and efficiently guarantee the ignitions process with liquid rocket engine. The propellant used is a Kerosene as fuel and a liquid oxygen as oxidizer. FOOF type of three injectors are set with an angle of 135。 and the combustion chamber pressure is 200psi. The present experiment program also includes the stability on the quadlet type of ignitor using the triehylaluminum (TEAL) as an ignition source. Experimental results clarifies that the propellant supply through LOx leading to combustion chamber is proper for stable ignition and combustion processes based on the fuel and oxidizer manifold pressures, combustion chamber pressure, and the variation of flame length from the nozzle exit with lapse time, and shows that the leading supply time pf propellants effects the engine performance little.

소형 액체 로켓 엔진에서의 점화 시퀀스 결정 및 인젝터 수명 연장 기법 평가 (Determination of Ignition Squence and Estimation of Injector Life Extension Technique in Liquid Rocket Engine)

  • 박정;김용욱;김영한;문일윤;이재룡;강선일;정용갑;조남경;오승협
    • 한국연소학회지
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    • 제5권1호
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    • pp.43-53
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    • 2000
  • Experimental studies on determination of the supply leading time of propellants to combustion chamber have been made to stably and efficiently guarantee the ignition process with liquid rocket engine. The propellant used is a Jet A-1 as fuel and a liquid oxygen as oxidizer. Unlike impinging FOOF type of injectors are arranged radially and the designed O/F ratio is 2.34. The present experiment program also includes the stability on the quadlet type of ignitor using the triethylalumimum as an ignition source and injector life tests. Experimental results clarifies that the propellant supply through LOx leading to combustion chamber is proper for stable ignition and combustion processes based on the fuel and oxidizer manifold pressures, combustion chamber pressure, and the variation of flame length from the nozzle exit with lapse time, and shows that the leading supply time of propellants affects the engine performance little. The effect of positioning cooling holes is remarkable to protect the injector face.

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Real-Time Enterprise Management

  • Hadavi, K.Cyus
    • 한국전자거래학회:학술대회논문집
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    • 한국전자거래학회 2002년도 e-Biz World Conference
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    • pp.9-16
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    • 2002
  • Adexa is a leading provider of supply chain planning and collaboration software. Our iCollaboration solution is used by Global 2000 companies to create Real-time Enterprise Management solutions(omitted)

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Covid-19 팬데믹시기 물류성과지수와 공급망 추적 데이터에 대한 고찰 (A Study on logistics Performance Index andSupply Chain Tracking Data during the Covid-19 Pandemic)

  • 안태건
    • 한국항만경제학회지
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    • 제39권3호
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    • pp.191-210
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    • 2023
  • Covid-19 팬데믹은 글로벌 물류와 공급망에 큰 영향을 미쳤으며, 이로 인해 세계 각국의 물류성능에 큰 차이가 발생하였다. 따라서 이 연구에서는 물류성과지수와 공급망 추적 데이터에 대한 고찰을 통해 펜데믹 기간 동안 발생된 글로벌 공급 사슬의 변화와 물류 환경 변화를 확인하고자 하였다. 물류성과지수를 분석한 결과 세관 및 통관 관리 효율성, 무역 및 운송 인프라의 품질, 물류 서비스의 능력과 품질, 화물 추적 능력 등의 지표에서 세계 국가들, 특히 선진국들은 전반적으로 성능 개선을 보였다. 반면, 국제 운송의 경쟁력 있는 가격 용이성과 화물의 정시 배송 빈도는 팬데믹의 영향으로 점수 하락을 보였다. 공급망 추적 데이터 분석에서 아시아 국가의 항구에서의 처리 효율성은 높게 나타났다. 그러나 미국과 유럽 국가들은 상대적으로 더 많은 시간이 소요되었다. 항공화물, 소포, 특송 운송에서 특히 미국의 경우 상대적으로 처리시간이 많이 걸리는 것으로 나타나 물류 지연이 발생하고 있었다. 결론적으로, Covid-19 팬데믹 동안 아시아 국가들은 물류 및 무역 환경에서 상대적으로 높은 효율성을 유지하였다. 반면, 미국과 일부 유럽 국가들은 여러 지표에서 지연과 효율성 저하를 보였다. 향후 지연현상과 정체현상 즉 물류 프로세스의 속도 감소를 해결하기 위한 노력들이 필요한 시점이라 판단된다.

고주파 인버터식 X-선관용 고전압 전원장치 (A High Voltage Power Supply for X-Ray Tube Using High Frequency)

  • 김학성;유동욱;조정구;백주원;임근희;원충연
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 F
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    • pp.2246-2248
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    • 1997
  • This paper presents a high-frequency inverter type high-voltage power supply for X-ray equipments. The high-voltage generator consist of an inverter unit including the SR(Series Resonance) type PSC(Phase-Shifted Control) PWM circuit adopting IGBT as the switching power device and high-voltage unit including the CW(Cockcroft Walton) circuit. When the X-ray equipment is radiographing at large power for a short time, this generator operates through feedback voltage mode control to obtain a high speed leading edge and low ripple. The operating modes and design consideration of the proposed power supply are given. Issues in the design of high-voltage divider for high voltage measuring. Experimental results are presented to verify the performance of the designed power supply for varying load conditions. The proposed apparatus has several advantages, e.g., the fast rising time of tube voltage, accuracy and reduced component size etc.

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공급망 ESG 관리에서 예상되는 분쟁 중재에 관한 연구 - 포스코와 네이버 사례를 중심으로 - (A Study on Expected Dispute Arbitration in Supply Chain ESG Management: Focusing on the cases of POSCO and NAVER)

  • 이건우;이정은;이훈종
    • 한국중재학회지:중재연구
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    • 제34권1호
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    • pp.75-101
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    • 2024
  • "ESG management" guides companies to prioritize corporate social responsibility and sustainable development as key management objectives, going beyond mere financial performance pursuits. This approach involves creating a sustainable and robust supply chain by urging companies, acting as 'supply chain managers', to implement ESG management practices alongside their 'supply chain partners'. The domestic business community has been quick to respond to this trend, recognizing that failure to adhere to ESG standards set by organizations such as the EU and SEC could lead to severe repercussions, including exclusion from international trade and reputational damage. POSCO and NAVER, two leading Korean companies, are at the forefront of practicing ESG management effectively. They have both produced and publicly disclosed ESG management reports, showcasing their success in enhancing supply chain ESG management. However, as supply chain managers enforce ESG-related obligations on their suppliers, the likelihood of disputes between the parties may increase. In scenarios where supply chain ESG management leads to conflicts between supply chain managers and suppliers, commercial arbitration emerges as a viable solution for dispute resolution. This method offers several advantages, including the arbitrators' expertise, time and cost efficiency, the binding nature of decisions akin to a court's final judgment, international recognition under the New York Convention, confidentiality, and ample opportunity for parties to be heard. Our analysis focuses on the emerging disputes between supply chain managers and suppliers within the context of supply chain ESG management, particularly examining the cases of POSCO and NAVER. By categorizing the expected types of disputes and assessing the appropriateness of commercial arbitration for their resolution, we highlight the effectiveness of this approach. Furthermore, we propose leveraging the Korean Commercial Arbitration Board's role to enhance the use of arbitration in resolving supply chain ESG disputes, underscoring its potential as a strategic tool for maintaining sustainable and harmonious supply chain relationships.

원전 건설공사를 위한 공급망관리체계 적용방안에 대한 기초연구 (A Fundamental Research for Adaptation Method of SCM in Korean Nuclear Power Plant Construction)

  • 박항순;원서경
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.229-231
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    • 2012
  • The supply chain in plant construction project can be defined as a network combined between elements which is engineering, procurement, construction, start-up. For successfully leading construction project, close relation and mutual cooperation should be preceded and Supply Chain Management(SCM) system is needed to improve the relation. In particular, because safety is a top priority for the companies work in the construction of Nuclear Power Plant(NPP), it is necessary to control all parties realated with NPP construction systematically. In this situation, it is important to purchase high-quality equipment in timely manner by developing Integrated cooperative systems. Therefore, this study aimed to propose developing solutions of SCM such as JIT and Envelop Design system, which can reduces difficulties of decision making between the parties involved in the project and will increase the efficiency of the engineering process in NPP.

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물류자동화시스템과 물류정보시스템의 통합구축 사례 (Integrated Approach to Develop a Logistics Automation & Information System)

  • 선지웅
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2001년도 추계학술대회 논문집
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    • pp.147-149
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    • 2001
  • Customer centered supply chain Management is becoming a very important issue for manufacturing and distribution company. Increasingly, leading companies improve their competitiveness by shorting the time to delivery from warehousing to delivering, increasing the level of customer service. They also do their best to collaborate with suppliers and customers based on the information sharing. This case introduces a integrated approach to develop a logistics automation and information system for the spare parts distribution center of L electronics. We pursue to optimize the supply chain by implementing intelligent logistics system which has the capabilities of responding to the changes in market demands. This would provide many implications to the clients in solving logistics problems and secure superior competitiveness.

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한국 철강산업의 국민경제적 파급효과 분석 (Role of the Korea Steel Industry in the National Economy Analysis)

  • 정군오;임응순
    • 한국산학기술학회논문지
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    • 제9권3호
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    • pp.831-839
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    • 2008
  • 전 세계적으로 철강산업의 중요성은 높아지고 있으며, 철강수요 역시 증가하고 있는 추세이다. 한국 철강산업의 철강생산량은 전 세계에서 5위를 차지하고 있어 국내에서는 철강산업에 대한 관심이 커져가고 있다. 또한 철강산업은 국내에서 경제성장을 이끌어 온 국가기간산업중의 하나이다. 이에 본 연구에서는 산업연관분석을 이용하여 철강산업이 국민경제에 미치는 파급효과들을 시계열로 분석하여 보고자 한다. 먼저 수요유도형 모형을 이용하여 생산유발효과, 부가가치 유발효과 그리고 취업유발효과를 살펴 볼 것이며, 아울러 공급유도형 모형 및 레온티에프 가격모형을 적용하여 철강산업의 공급지장효과와 물가파급효과에 대하여 살펴보고자 한다.

The investment point on cooperative innovation in EVs for the spoke-smart cities : focused on Nordic countries and Korea

  • Seo, Dae-Sung
    • 융합경영연구
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    • 제5권3호
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    • pp.1-11
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    • 2017
  • E-infrastructural economy for ICT Living-Labs is a need for economic and cultural changes in various types of cars in accordance with the supply of the electric car. Depending on the number of cases by analyzing the supply and demand of electric vehicles among Korea and Northern Europe countries. it was indirectly proved that it makes economic growth. The research design is analyzed with the data and how to respond quickly to focus on the possibility of potential changes to the infrastructure realization and commercialization of government enterprises or electric cars through the ICT Living-Labs in Nordic countries. The data indicates that the leading commercialization emphasize on the development of the electric economic convergence and scalability for electric vehicle. When It shows the time of the infrastructure as ICT Living-Labs being delayed, it lowered growth target results for the development of the electric car industry in the future. All this is from the reason of opening the E-convergence economy over time. It is required that Korea should prepare E-convergence economy. Public regional energy should be present through the consistent selection of development for energy linking E-economy and E-trans distribution. Korea needs to be many difficulties in building the E- infrastructure for ICT Living-Labs. Unlike the Northern Europe it is to prepare the active support of both government and business. The role of the government discovers that the power generation through the quick selection of the industry, as well as to connect with the growth of the smart cities with the EVs industry.