• 한국환경과학회지
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• 제31권7호
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• pp.543-553
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• 2022

The latest aerospace technology is important for the stable flight of a launch vehicle, but weather conditions on the day of launch are also one of the essential factors for successful launch campaign. If a launch vehicle is directly struck while preparing to take off from the launch pad on the day of launch or the electronic device are damaged by induced current during flight of the launch vehicle, this means launch failure and can lead to enormous national loss. Therefore, for a successful launch campaign, it is necessary to analyze the lightning detection characteristics of the Naro Space Center. In this study, the seasonal factors of the lightning that occurred over the Naro Space Center from 2003 to 2017, the influence of the polarity, and the correlation with the lightning intensity was confirmed. As a result, there was a high probability of intensive occurrence of multiple lightning strikes in summer, and a high proportion of positive (+) lightning strikes in winter. Lastly, in the distribution of the number of lightning strikes, an average of 2.0 to 2.5 negative (-) lightning strikes occurs in the coastal regions of the South and West Seas when one flash happens.

• 한국항공우주학회지
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• 제36권3호
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• pp.291-297
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• 2008

아리안-5 발사체를 이용한 통신해양기상위성 발사에 대하여 소개되었다. 먼저, 통신해양기상위성이 간단히 소개되고, 20%의 추력 향상을 위한 아리안-5G 발사체의 발칸-1 엔진으로부터 아리안-5ECA 발사체의 발칸-2 엔진으로의 개량에 대한 상세한 설명을 포함하여 아리안 5 발사체에 대하여 소개되었다. 그 다음 통신해양기상위성의 발사과정에 대하여 소개되었다. 아리안-5 발사체는 남미 프랑스령 기아나의 쿠루시에 있는 기아나스페이스센터에서 발사된다. 위성처리시설에서 최종점검을 마치면 같은 건물 내의 위험처리시설로 옮겨져 연료를 주입하고, 그곳에서 발사체 어댑터에 결합된 후 최종조립건물로 이동된다. 최종조립건물 내의 발사 테이블 위에서 조립되는 발사체 위에 같이 발사될 위성들이 결합된 후 발사 테이블이 발사체를 싣고 발사대로 이동하여 발사한다. 발사체가 비행하는 동안의 비행 과정에 대해서도 소개되었다.

• 한국항공우주학회지
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• 제44권8호
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• pp.657-665
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• 2016

발사관제시스템은 발사캠페인 기간 중 지상의 발사 준비 및 발사 운용 임무를 수행한다. 보통 발사 운용의 성공 여부는 발사관제시스템의 하드웨어나 소프트웨어에 의해 크게 영향을 받는다. 특히 제어 알고리즘의 사소한 오류조차 발사 운용에 심각한 문제나 재난을 유발 시킬 수 있다. 따라서 내재된 오류를 사전 검증시험을 통해 찾아내 제거해야 한다. 본 논문은 발사관제시스템 검증에 사용된 하드웨어와 소프트웨어 시뮬레이터의 설계와 구현에 대해 소개한다. 시뮬레이터의 상세한 설계와 플로차트 형식의 구체적인 알고리즘을 기술하여 유사한 시스템의 구현에 적용할 수 있도록 하였다. 특히 별도의 컴퓨터나 PLC를 사용하지 않고 자체 제어기에서 모든 시뮬레이션 알고리즘이 동작하도록 개발한 점을 강조한다.

• 항공우주기술
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• 제3권2호
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• pp.133-140
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• 2004

대기의 기상 상태는 시, 공간적으로 매우 불규칙적으로 변화하여 경우에 따라서 위성 발사체에 치명적인 영향을 미치고 있다. 따라서 위성 발사체의 순조로운 발사를 위하여 기상 상태의 정확한 실시간 관측이 필수적이라 할 수 있다. 본 연구는 기상관측 시스템인 기상레이더의 일반적인 제원을 소개하며, 우주센터용으로 적합한 기상 레이더 시스템의 운용개념 및 요구특성을 송신출력, 안테나 이득, 빔 폭 및 최적 감지신호 등을 종합적으로 고려하여 분석하였다.

• 한국기계가공학회지
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• 제18권12호
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• pp.104-110
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• 2019

A nanosatellite designed by the Korea Microgravity Science Laboratory (KMSL) is currently under development. The KMSL nanosatellite is designed to perform two different scientific missions in space. To successfully complete missions, a variety of tests must be conducted to verify the performance of the designed satellite before launch. As part of the qualification test campaign, the KMSL nanosatellite underwent high level vibrational tests (to comply with Falcon 9 qualification level) to demonstrate the integrity of the system. The purpose of this study is to demonstrate that the primary structure and all electronic and mechanical components can withstand the vibrations and the loads experienced during the launch period. To this end, the KMSL nanosatellite was exposed to static and dynamic loads and various types of vibrations that are inevitably produced during the space vehicle launch period. The vibration test results clearly demonstrated that all avionics and mechanical components can withstand the vibrations and the loads applied to the KMSL nanosatellite's body through a Pico-satellite Orbital Deployer (POD).

• 항공우주기술
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• 제4권1호
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• pp.108-113
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• 2005

본 연구 에서는 고해상도 우주용 카메라의 경통부의 복합재 적층설계를 열환경 및 흡습에 의한 영향을 고려하여 수행하고 다층 지그재그이론에 기초하여 개발된 삼각형 유한요소를 이용 열흡 습 해석을 수행하여 융단도표를 통하여 도출된 최적 적층설계가 광학성능 허용범위를 만족하는지 검증 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권3호
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• pp.1006-1027
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• 2022

In the crowdfunding market, various crowdfunding platforms can offer founders the possibilities to collect funding and launch someone's next campaign, project or events. Especially, healthcare crowdfunding is a field that is growing rapidly on health-related problems based on online platforms. One of the largest platforms, GoFundMe, has raised US$ 5 billion since 2010. Unfortunately, while providing crucial help to care for many people, it is also increasing risk of fraud. Using the largest platform of crowdfunding market, GoFundMe, we conduct an exhaustive search of detection on fraud from October 2016 to September 2019. Data sets are based on 6 main types of medical focused crowdfunding campaigns or events, such as cancer, in vitro fertilization (IVF), leukemia, health insurance, lymphoma and, surgery type. This study evaluated a detect of fraud process to identify fraud from non-fraud healthcare crowdfunding campaigns using various machine learning technics.

• Asia Marketing Journal
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• 제14권3호
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• pp.169-184
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• 2012

All firms require new stimulus to spurt growth. Therefore it is necessary to successfully develop new products and to employ appropriate marketing practices for the new products to enter and settle in the market. Binggrae, a Korean company that specializes in dairy and processed dairy products, introduced a ready-to-drink (RTD) coffee product, 'a Café la' to expand its business into the coffee market in 2008. Binggrae was a latecomer in the RTD coffee market but a Café la has shown an impressive average sales growth rate of 115% as of 2011 since the launch. Moreover, it is a steady bestselling coffee brand among the Polyethylene terephthalate (PET)bottle category. Binggrae found potential and opportunity in the growing coffee market and made efforts to develop a new product that can be differentiated from the existing products. The result was PET bottle coffee, which was more portable and convenient to drink than coffee products offered in cups or cans. PET bottle coffee is produced through the patented Aseptic Filing System, thus the original coffee flavor stays fresh when combined with milk and has a longer shelf life than coffee products in cups. Moreover, as the taste of coffee consumers has become more sophisticated, Binggrae developed a premium product by differentiating the product processing method and by using higher-quality Arabica beans. After launching the new product, the company also employed a well-designed communication strategy. First, Binggrae was able to confirm the level of market demand and market potential for the product by employing BTL (Below the Line) marketing strategies through the consumers' word-of-mouth. Afterwards, the company invested its resources for a full-scale ATL (Above the Line) marketing campaign. Later a Café la's TV commercial effectively portrayed the product's characteristics, and succeeded in raising consumer awareness of the product. As a result, a Café la has become the bestselling brand in the PET bottle coffee market. The successful new product marketing strategy of Binggrae'sa Café la offers many valuable implications for companies planning to launch new products in the future.

• Advances in aircraft and spacecraft science
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• 제5권2호
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• pp.205-223
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• 2018

During launch a spacecraft is subjected to a variety of dynamical loads transmitted through the launcher to spacecraft interface or air-born transmission excitations in the acoustic pressure field inside the fairing. As a result, spacecraft are tested on ground to ensure and demonstrate the global integrity of the structure against these loads, to screen the flight hardware for quality of workmanship and to validate mathematical models. This paper addresses the numerical modelling and simulation of the low frequency sine and random vibration tests performed on electrodynamic shaker facilities to comprise the mechanical-borne transmission loads through the launcher to spacecraft interface. Consequently, the paper reviews techniques and methodologies to derive a reliable and representative coupled virtual vibration testing simulation environment based on experimental data. These technologies are explored with the main objectives to ensure a stable, reliable and accurate control while testing. As a result, the use of the derived simulation models in combination with the added value of improved control and signal processing algorithms can lead to a safer and smoother vibration test control of the entire environmental test campaign.

• 천문학회지
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• 제44권2호
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• pp.67-72
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• 2011

We report the results of our high resolution optical spectroscopic monitoring campaign (${\lambda}$ = 3800 ~ 8800 ${\AA}$, R = 30000 - 45000) of the new FU Orionis-type object HBC 722. We observed HBC 722 with the BOES 1.8-m telescope between November 26 and December 29, 2010, and FU Orionis itself on January 26, 2011. We detect a number of previously unreported high-resolution K I and Ca II lines beyond 7500 ${\AA}$. We resolve the H${\alpha}$ and Ca II line profiles into three velocity components, which we attribute to both disk and outflow. The increased accretion during outburst can heat the disk to produce the relatively narrow absorption feature and launch outflows appearing as high velocity blue and red-shifted broad features.