• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.2
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• pp.139-155
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• 2016

Present paper introduces the recent advances in space launch vehicle technologies. A brief survey is given for the space development programs in civil sector with their business model and key technologies. Advances in key technologies were reviewed in detail with more emphasis on the electric pump cycle engine for low cost high performance small launch vehicle, Electron, under development by Rocketlab Ltd., since their contributions would give good lessons for rocket scientists.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.345-348
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• 2008

The computer-aided performance simulation can reduce periods for development of products and cut down on the cost comparing with former trial-and-error procedures. This study has developed a simulation program for a vehicle thermal management system integrating an engine cooling system and an air conditioning system considering interactions and arrangement of air side heat exchangers such as power steering oil cooler, air-cooled transmission oil cooler, condenser, and radiator. The program may be also used for the system performance analysis according to the configuration of the engine coolant side heat exchangers such as water-cooled transmission oil cooler, EGR cooler, and heater core. Experiments utilizing an environmental wind tunnel has been conducted to assess the performance of the system according to the arrangement of air side heat exchangers. Some modification of the coolant loop layout can enhance the heat core performance up to 7% according to the results of the simulations.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.441-445
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• 2000

Considering international status of our country as world class ship builder and geographical characteristics encircled by sea in three facets, controlling of air pollutants emission from marine engines becomes more and more important issue in recent days. Implementation of immediate pollutants emission control regulation and standardization of test and certification procedure are required to reduce air pollution from marine engines. But cost increments due to additional equipment of emission control device and development and certification test expenses as well as depreciation of fuel economy should be considered. To satisfy those air pollution reduction and economic requirements, we should make our own interpretation of IMO standard and implementation schedule depending on our country's status. For this purpose we measured NOx emission from small and middle class marine engines to calculate emission factor and total pollutant emission in our country. With the comparison and analysis of other countries emission control regulation we proposed basic data of total emission from marine engine and future emission control standard in our country. According to our estimation, 62% of total NOx emission of marine engines comes from fishing boat and 38% from commercial vessels. The portion of NOx emission from marine engine is 18.6% of whole country NOx emission. Due to the voyage characteristics of middle and large vessel and necessity of international harmonization of marine engine pollutants emission control standard, it is inevitable to adopt IMO standard for middle and large marine engines. But considering technological and cost effect of fishing boat operating in near sea, it is resonable to set a standard within 80% of measured value at the moment and gradually implement the same IMO standard in near future.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.54-63
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• 2015

Increasing air pollution levels and the global oil crisis has become a major hindrance in the growth of our automobile sector. Traditional Internal Combustion engines running on non-renewable fuels are proving to be the major culprit for the harmful effects on environment. With few modifications and also with assistance of few additional components current small SI engines can be modified into a pneumatic engine (commonly known as Compressed Air Engines) without much technical complications where the working fluid is compressed air. The working principle is very basic as adiabatic expansion of the compressed air takes place inside the cylinder pushing the piston downwards creating enough MEP to run the crank shaft at decent RPM. With the assistance of new research and development on pneumatic engines can explore the potential of pneumatic engines as a viable option over IC engines. The paper deals with analysis on RPM variation with corresponding compressed air injection at different crank angles from TDC keeping constant injection time period. Similarly RPM variation can also be observed at different injection pressures with similar injection angle variation. A setup employing a combination of magnetic switch (reed switch), magnets and solenoid valve is used in order to injection timing control. A conclusive data is obtained after detailed analysis of RPM variation that can be employed in newly modified pneumatic engines in order to enhance the running performance. With a number of benefits offered by pneumatic engine over IC engines such as no emissions, better efficiency, low running cost, light weight accompanied by optimized injection conditions can cause a significant development in pneumatic engines without any major alteration.

• Current Industrial and Technological Trends in Aerospace
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• v.8 no.2
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• pp.86-97
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• 2010

This paper treats with the history and current trends in the developments of liquid-propellant rocket engine in Russia and Ukraine which are among world leaders in the technology of liquid rocket engine(LRE). In 1960s formerly the Soviet Union accepted the closed cycle engine for increasing the pressure in the combustion chamber and specific impulse to the maximum. However, since financially difficult times after 1990, they have decreased the cost for the development of new rocket engines. It was achieved by using existing units for new developed engines and minimizing the total number of engines and tests through the reasonable planning in the process for the experimental improvement of LRE. In addition, nowadays international cooperation in supplying LRE for commercial rocket and development of next generation LRE, such as 3 components engines and mathane engines, are proceeding.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.3
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• pp.86-93
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• 2011

Recently, development and application of condition monitoring and diagnostic system for improvement of durability and reliability and reduction of operating cost is generalized in the aircraft propulsion system. Expecially, for reliable operation of the high altitude and a long time and condition monitoring system to identify faults and degradations of its propulsion system should be needed. This work proposed a GUI-based On-line condition monitoring program using LabVIEW by PT6A-67 turboprop engine. The proposed on-line condition program can monitor the real engine performance as well as the trend through precise comparison between performance results calculated by the base performance simulation program and measuring engine performance signals. In the development phase of this monitoring system, a signal generation module is proposed to evaluate the proposed on-line monitoring system.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.6
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• pp.727-737
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• 1999

프로세스 중심 소프트웨어 개발 환경(PSEE : Process-centered Software Engineering Environment)은 소프트웨어 개발자를 위한 여러가지 정보의 제공과 타스크의 수행, 소프트웨어 개발 도구의 수행 및 제어, 필수적인 규칙이나 업무의 수행등과 같은 다양한 행위를 제공하는 프로세스 모형의 수행을 통하여 소프트웨어 개발 행위를 지원한다. SEED(Software Engineering Environment for Development)는 효율적인 소프트웨어 개발과 프로세스 모형의 수행을 제어하기 위해 ETRI에서 개발된 PSEE이다.본 논문에서는 SEED에서 프로세스 모형을 설계하기 위해 사용되는 SimFlex 프로세스 프로그래밍 언어와, 수행지원시스템인 SEED Engine의 구현에 대하여 기술한다. SimFlex는 간단한 언어 구조를 가진 프로세스 프로그래밍 언어이며, 적절한 적합화를 통하여 다른 PSEE에서 사용될 수 있다. SimFlex 컴파일러는 SimFlex에 의해 기술된 프로세스 모형을 분석하고, 모형의 오류를 검사하며, SEED Engine에 의해 참조되는 중간 프로세스 모형을 생성한다. 중간 프로세스 모형을 사용하여 SEED Engine은 외부 모니터링 도구와 연관하여 사용자를 위한 유용한 정보뿐만 아니라 SimFlex에 의해 기술된 프로세스 모형의 자동적인 수행을 제공한다. SimFlex 언어와 수행지원 시스템의 지원을 통하여 소프트웨어 프로세스를 모형화하는데 드는 비용과 시간을 줄일 수 있으며, 편리하게 프로젝트를 관리하여 양질의 소프트웨어 생산물을 도출할 수 있다. Abstract Process-centered Software Engineering Environments(PSEEs) support software development activities through the enaction of process models, providing a variety of activities such as supply of various information for software developers, automation of routine tasks, invocation and control of software development tools, and enforcement of mandatory rules and practices. The SEED(Software Engineering Environment for Development) system is a PSEE which was developed for effective software process development and controlling the enactment of process models by ETRI.In this paper, we describe the implementation of the SimFlex process programming language used to design process models in SEED, and its runtime support system called by SEED Engine. SimFlex is a software process programming language to describe process models with simple language constructs, and it could be embedded into other PSEEs through appropriate customization. The SimFlex compiler analyzes process models described by SimFlex, check errors in the models, and produce intermediate process models referenced by the SEED Engine. Using the intermediate process models, the SEED Engine provides automatic enactment of the process models described by SimFlex as well as useful information for agents linked to the external monitoring tool. With the help of the SimFlex language and its runtime support system, we can reduce cost and time in modeling software processes and perform convenient project management, producing well-qualified software products.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.73-80
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• 2015

It had been almost a half century since Apollo Mission was ended. However, in these days, a lot of researches are being conducted for restoration and making improvements in technologies used in Saturn V rocket's development. This study reviews the first stage of Saturn V rocket(S-IC), from development history to technologies in various subsystems such as engine purge system, POGO suppression system, hydraulic and pneumatic control system, propellant dispersion system, telemetry system and retrorocket system. Understandings of S-IC stage's operation systems would be helpful in understanding of launch vehicle system and reduction of time and cost in future development process.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.102-118
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• 2022

With the development of digital content software production technology and the technological progress of related hardware, the social status quo in the post-epidemic era, the popularization and application of 5G networks, the market and consumers' increasing demand for digital content products, artificial intelligence, virtual digital human, virtual Idols, virtual live, self-media content and metaverse-related content industries are all developing rapidly. Virtual idols, virtual digital human, etc. are not only accelerating innovation in production technology. The economic cost, technical difficulty and time requirements of production are also greatly reduced. With the arrival and development of the Metaverse, the author believes that the content industry with virtual digital humans as the core will continue to develop in the direction of refinement, specialization, facilitation and customization. In this article, we will analyze and study the production of virtual digital human based on Photoscan technology and Unreal Engine 5 Metahuman software, and discuss the application status and future development of related content.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1361-1366
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• 2007

Forging for spring cup of engine valve was investigated in this study. New method is needed to reduce cost and development lead time required to fix forming process of new product, that eventually can provide die, metal flow and forming loads with high confidence level. FEM could provide required detail information that could reduce trial error in advance before the actual production. By using the rigid-plastic finite element simulation, possibilities of improving former research were explored. Results generated by FEM could foresee expected material deformation in advance and made possible new forming process successfully.