• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.65-73
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• 2008

As the system requirements of performance, weight, cost are increasing, the needs of electronic parts which have high performance and efficiency are growing. To satisfy such requirements, demand of high performance and rapid upgraded commercial parts is also increasing compared to NASA or ESA standard parts. Especially, commercial PEM(Plastic Encapsulated Microcircuit) parts are applied in many space programs and research is continuing to broaden its application area. In this paper, concerns and verification trends of commercial PEM parts in space applications are introduced.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.9
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• pp.931-938
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• 2009

The flight test is last means of compliance to satisfy airworthiness standards and important to evaluate the performance and safety of the developed aircraft. The flight test technologies are obtained from great numbers of experiences and know-hows and protected. In addition, flight test should be conducted efficiently since its various test conditions and items. Therefore, it is requisite to secure efficient flight test methods. This paper discusses the flight test methods for take-off and landing performance and two kinds of techniques are proposed. By performing real flight tests, they are compared with each other and analyzed through the flight analysis.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.224-230
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• 2015

항공기 엔진 체계의 신뢰성과 안전성을 분석하는 것은 RAM 분석이라고 한다. RAM은 제작자가 개발한 시스템의 지속가능성 혹은 그 체계의 수명주기비용(Lice Cycle Cost)에 중대한 영향을 줄 수 있는 시스템 설계특성을 의미한다. 또한 RAM은 시스템이 개발될 당시에 의도된 임무를 수행할 수 있는 능력 혹은 임수수행을 성공할 수 있도록 담보하는 중요한 역할을 한다. RAM은 1970년대 이후 미국 군수분야에서는 군수지원성분석(LSA, Logistic Support Analysis) 과 밀접히 연계되어 활용되어 왔으며, RAM과 LSA를 통합하여 종합군수지원체계(ILS, Integrated Logistics Support)라고 부른다. 본 연구에서는 항공기 엔진에 대한 신뢰성 분석에 Weibull 분포를 활용하였다. Weibull 분포는 2개의 변수 적용에서 다음과 같이 정의된다. 변수가 그 계의 어떤 값을 나타내느냐에 따라 분포도 곡선의 특성 의미는 변수에 의존된다. 예를 들어 시험성적, 사회적 특성을 표현하는 인지도, 산업 제품의 고장이나 결함을 나타내는 고장관련 모수(변수) 등에 따라 그 특징을 나타내게 된다. 항공기 엔진의 신뢰성 분석을 통해 항공기 엔진의 수명 판단이 가능해졌으며 임무 불가능 수준의 In-Flight Shut-Down 비율이 현격히 감소됨을 확인할 수 있었다.

• Current Industrial and Technological Trends in Aerospace
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• v.9 no.1
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• pp.130-138
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• 2011

A vent relief valve performs as a safety valve, which ensures ventilation of propellant tank during filling and protection from tank overpressure after filling. Because of the reliability and cost saving, the virtually same vent relief valve has been used on all US cryogenic liquid fueled launch vehicles. Some modification to the valve has been applied to satisfy the various mission requirements of launch vehicles. This paper reviews the main technology trends of the vent relief valve applied to the propellant feed system for launch vehicle with respect to design and manufacture. This paper also introduces the operating technology of vent relief valve applied for launch vehicles of advanced countries in space development.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.554-559
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• 2017

Recently, the global attention is focused on the development of the renewal aero-propulsion systems proved in the air pollution, the noise, the great operational cost, safety and risks. Especially, various study are conducting for the development of the advanced high power to weight ratio aircraft through the significant reduction of fuel consumption and upgrade of the propulsion efficiency, using the alternative propulsion system developments such as hydrogen and solar power system. The hybrid propulsion system can be the representative propulsion system which get the power sources by combining the merits of two or more power sources. In this study, the advancement trends, characteristics, design method which can be applied to the renewal future UAV development.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.6
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• pp.488-496
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• 2015

This paper proposes a framework to determine the routes of multiple unmanned aerial vehicles (UAVs) to conduct multiple tasks in different locations considering the survivability of the vehicles. The routing problem can be formulated as the vehicle routing problem (VRP) with different cost matrices representing the trade-off between the safety of the UAVs and the mission completion time. The threat level for a UAV at a certain location was modeled considering the detection probability and the shoot-down probability. The minimal-cost path connecting two locations considering the threat level and the flight distance was obtained using the Dijkstra algorithm in hexagonal cells. A case study for determining the optimal routes for a persistent multi-UAVs surveillance and reconnaissance missions given multiple enemy bases was conducted and its results were discussed.

• Journal of Aerospace System Engineering
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• v.16 no.4
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• pp.28-34
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• 2022

In 2021, Virgin Orbit converted a 747-400 aircraft into an air launch platform, and successfully launched it twice in February and July. Compared to the existing ground launch, interest in the air launch is increasing due to its great utility, such as its independence from the launch location or weather, cost reducing factor, shorter launch preparation time, and its benefit pursuant to altitude and speed. Additionally, as small satellites have similar performance to mid/large satellites in the past due to the miniaturization and precision of electronic equipment, small satellite launches are expected to dominate in the future. In this paper, institutional certification methods such as domestic, overseas, civilian and military airworthiness certification regulations/procedures are reviewed to ensure flight safety of aerial projectiles using large domestic civil aircraft, and applicable civil and military airworthiness certification technology standards are reviewed and analyzed. Additionally, we will review and suggest effective airworthiness certification application plans that reflect the reality, and present airworthiness certification standards (draft) for aerial launch vehicles, by analyzing applicable airworthiness certification technical standards when remodeling aerial launch vehicles.

• Journal of Aerospace System Engineering
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• v.12 no.3
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• pp.70-78
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• 2018

This research was carried out to develop an integrated folding wing made from carbon composite materials. Design requirements were reviewed and composite wing sizing was conducted using design optimization with commercial software. Three composite manufacturing processes including hot-press, pultrusion, and autoclave were evaluated and the most suitable processes for the integrated wing fabrication were selected, with consideration given to performance and cost. The determined manufacturing process was verified by two design development tests for selecting the design concept. Stiffness and strength of the composite wing were estimated through structural analyses. The test loads were calculated and static tests about design limit load and design ultimate load were performed using both wings. As a result, the evaluation criterions of the tests were satisfied and structural safety was verified through the series of structural analyses and testing.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.89-102
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• 2010

In this paper, a study on the future-oriented actuator introduces the future technology and future direction in aerospace and several industry fields. In particular, the mechanical linkage or hydraulic and pneumatic actuators which have the higher output-to-weight ratio have been used a lot in the past as the aircraft's flight control device. Most recently, Fly-By-Wire system has been used in aircraft and the flight control system has been changed in more electric and all electric systems. Electrohydraulic actuators and electric actuators have been developed continually, because they have better efficiency, safety and lower cost for the flight control system of aircraft. Also, to improve the weight condition, accuracy and response of actuator, new field actuators using new materials have been developed. In this paper we clearly proposed the actuator design and detailed technology development trend for next generation actuation system in aerospace and new field.

• Journal of Intelligence and Information Systems
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• v.21 no.1
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• pp.65-82
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• 2015

Recently, there has been a surge of interest in finding core issues and analyzing emerging trends for the future. This represents efforts to devise national strategies and policies based on the selection of promising areas that can create economic and social added value. The existing studies, including those dedicated to the discovery of future promising fields, have mostly been dependent on qualitative research methods such as literature review and expert judgement. Deriving results from large amounts of information under this approach is both costly and time consuming. Efforts have been made to make up for the weaknesses of the conventional qualitative analysis approach designed to select key promising areas through discovery of future core issues and emerging trend analysis in various areas of academic research. There needs to be a paradigm shift in toward implementing qualitative research methods along with quantitative research methods like text mining in a mutually complementary manner. The change is to ensure objective and practical emerging trend analysis results based on large amounts of data. However, even such studies have had shortcoming related to their dependence on simple keywords for analysis, which makes it difficult to derive meaning from data. Besides, no study has been carried out so far to develop core issues and analyze emerging trends in special domains like the aviation industry. The change used to implement recent studies is being witnessed in various areas such as the steel industry, the information and communications technology industry, the construction industry in architectural engineering and so on. This study focused on retrieving aviation-related core issues and emerging trends from overall research papers pertaining to aviation through text mining, which is one of the big data analysis techniques. In this manner, the promising future areas for the air transport industry are selected based on objective data from aviation-related research papers. In order to compensate for the difficulties in grasping the meaning of single words in emerging trend analysis at keyword levels, this study will adopt topic analysis, which is a technique used to find out general themes latent in text document sets. The analysis will lead to the extraction of topics, which represent keyword sets, thereby discovering core issues and conducting emerging trend analysis. Based on the issues, it identified aviation-related research trends and selected the promising areas for the future. Research on core issue retrieval and emerging trend analysis for the aviation industry based on big data analysis is still in its incipient stages. So, the analysis targets for this study are restricted to data from aviation-related research papers. However, it has significance in that it prepared a quantitative analysis model for continuously monitoring the derived core issues and presenting directions regarding the areas with good prospects for the future. In the future, the scope is slated to expand to cover relevant domestic or international news articles and bidding information as well, thus increasing the reliability of analysis results. On the basis of the topic analysis results, core issues for the aviation industry will be determined. Then, emerging trend analysis for the issues will be implemented by year in order to identify the changes they undergo in time series. Through these procedures, this study aims to prepare a system for developing key promising areas for the future aviation industry as well as for ensuring rapid response. Additionally, the promising areas selected based on the aforementioned results and the analysis of pertinent policy research reports will be compared with the areas in which the actual government investments are made. The results from this comparative analysis are expected to make useful reference materials for future policy development and budget establishment.