• Title/Summary/Keyword: Supply Leading Time

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

  • Park, Jeong;Kim, Yong-Wook;Kim, Young-Han;Lee, Jae-Yong;Chung, Yong-Gahp;Cho, Nam-Kyung;Oh, Seung-Hyub
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.11
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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.

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

  • Park, Jeong;Kim, Yong-Wook;Kim, Young-Han; Moon, Il-Yoon;Lee, Jae-Yong;Kang, Sun-Il;Chung, Yong-Gahp;Cho, Nam-Kyung;Oh, Seung-Hyup
    • Journal of the Korean Society of Combustion
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    • v.5 no.1
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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
    • Proceedings of the CALSEC Conference
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    • 2002.01a
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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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A Study on logistics Performance Index andSupply Chain Tracking Data during the Covid-19 Pandemic (Covid-19 팬데믹시기 물류성과지수와 공급망 추적 데이터에 대한 고찰)

  • Ahn, TaeKun
    • Journal of Korea Port Economic Association
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    • v.39 no.3
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    • pp.191-210
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    • 2023
  • The Covid-19 pandemic has had a significant impact on global logistics and supply chains, leading to major discrepancies in logistics performance across countries worldwide. Through an examination of logistics performance index and supply chain tracking data, this study aimed to identify the changes in global supply chains and logistics environments during the pandemic. The analysis of the logistics performance index showed that overall, countries around the world, especially developed nations, showed improvements in metrics such as customs and border management efficiency, the quality of trade and transport infrastructure, capability and quality of logistics services, and cargo tracking abilities. However, the competitive pricing feasibility of international transportation and the on-time delivery frequency of goods saw a decline due to the pandemic's effects. The supply chain tracking data revealed that ports in Asian countries demonstrated high processing efficiency. In contrast, the U.S. and European countries took comparatively more time. Particularly for air cargo, parcels, and express shipments, the U.S. showed relatively longer processing times, leading to logistical delays. In conclusion, during the Covid-19 pandemic, Asian countries maintained relatively high efficiency in their logistics and trade environments. Conversely, the U.S. and some European countries showed delays and decreased efficiency in various metrics. In the future, efforts should be made to address delays and congestion, namely, the deceleration of logistics processes.

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

  • Kim, H.S.;Yoo, D.W.;Cho, J.G.;Back, J.W.;Rim, G.H.;Won, C.Y.
    • Proceedings of the KIEE Conference
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    • 1997.07f
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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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A Study on Expected Dispute Arbitration in Supply Chain ESG Management: Focusing on the cases of POSCO and NAVER (공급망 ESG 관리에서 예상되는 분쟁 중재에 관한 연구 - 포스코와 네이버 사례를 중심으로 -)

  • Lee, Geonwoo;Lee, Jungeun;Lee, Hunjong
    • Journal of Arbitration Studies
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    • v.34 no.1
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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.

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

  • Park, Hang-Soon;Won, Seo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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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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Integrated Approach to Develop a Logistics Automation & Information System (물류자동화시스템과 물류정보시스템의 통합구축 사례)

  • 선지웅
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2001.10a
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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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Role of the Korea Steel Industry in the National Economy Analysis (한국 철강산업의 국민경제적 파급효과 분석)

  • Jung, Kun-Oh;Lim, Eung-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.3
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    • pp.831-839
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    • 2008
  • The steel industry is becoming more important around the world and the demand of steel is increasing. Korea is the 5th country of steel producing in the world and the attention in the steel industry is growing. The steel industry is one of the key industry in leading the economic growth in Korea. This study attempts to analyze by time-series the economic impacts of the steel industry using an inter-industry analysis Specifically, the study investigates production-inducing effect, value added inducing effect and employ-inducing effect of the steel industry based on demand-driven model and the study deals with supply shortage effect and sectoral price effect of the steel industry by using supply-driven model and Leontief price model.

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

  • Seo, Dae-Sung
    • The Journal of Economics, Marketing and Management
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    • v.5 no.3
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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.