• 한국정보시스템학회지:정보시스템연구
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• 제31권3호
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• pp.177-195
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• 2022

Purpose This paper aims to prepare a full operational readiness by establishing an optimal flight plan considering the weather conditions in order to effectively perform the mission and operation of military aircraft. This paper suggests a flight prediction model and rules by analyzing the correlation between flight implementation and cancellation according to weather conditions by using big data collected from historical flight information of military aircraft supplied by Korean manufacturers and meteorological information from the Korea Meteorological Administration. In addition, by deriving flight rules according to weather information, it was possible to discover an efficient flight schedule establishment method in consideration of weather information. Design/methodology/approach This study is an analytic study using data mining techniques based on flight historical data of 44,558 flights of military aircraft accumulated by the Republic of Korea Air Force for a total of 36 months from January 2013 to December 2015 and meteorological information provided by the Korea Meteorological Administration. Four steps were taken to develop optimal flight prediction models and to derive rules for flight implementation and cancellation. First, a total of 10 independent variables and one dependent variable were used to develop the optimal model for flight implementation according to weather condition. Second, optimal flight prediction models were derived using algorithms such as logistics regression, Adaboost, KNN, Random forest and LightGBM, which are data mining techniques. Third, we collected the opinions of military aircraft pilots who have more than 25 years experience and evaluated importance level about independent variables using Python heatmap to develop flight implementation and cancellation rules according to weather conditions. Finally, the decision tree model was constructed, and the flight rules were derived to see how the weather conditions at each airport affect the implementation and cancellation of the flight. Findings Based on historical flight information of military aircraft and weather information of flight zone. We developed flight prediction model using data mining techniques. As a result of optimal flight prediction model development for each airbase, it was confirmed that the LightGBM algorithm had the best prediction rate in terms of recall rate. Each flight rules were checked according to the weather condition, and it was confirmed that precipitation, humidity, and the total cloud had a significant effect on flight cancellation. Whereas, the effect of visibility was found to be relatively insignificant. When a flight schedule was established, the rules will provide some insight to decide flight training more systematically and effectively.

• 한국추진공학회지
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• 제26권3호
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• pp.32-42
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• 2022

한가지 유형의 엔진 여러 개를 번들로 묶어서 발사체 제품군을 개발하는 전략은 SpaceX와 그들의 재사용 발사체 Falcon 9과 Falcon Heavy에 의해 입증되었다. 이 연구에서 우리는 35톤급 메탄 다단 연소 사이클 엔진을 이용한 잠재적인 발사체 제품군을 제시하였으며, 다양한 우주 임무에서 그것들의 유용성과 성능을 평가하였다. 예를 들어, Falcon 9의 한국형 버전은 소모성 모드에시 500 km SSO에 약 4.7톤의 탑재체를 투입할 수 있는 반면에, 해상에 착륙하는 모드에서는 약 2.16톤의 탑재량으로 줄어들게 된다. Falcon Heavy의 한국형 버전은 나로우주센터에서 발사되었을 때, 4.4톤을 GTO에 투입할 수 있으며, 이는 이 공통부스터코어 구성이 높은 경사각에도 불구하고 천리안 2호 위성을 투입할 수 있는 것으로 나타났다. 개발 후, 이 메탄 엔진이 소형위성 발사체에 추력공급 용도로도 사용도 가능하다.

• 무역상무연구
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• 제45권
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• pp.191-238
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• 2010

The purpose of this paper is to make research on the trend of the worldwide medical device market, the trend of the medical device market in the major foreign countries, the present status of the medical device industry in Korea and Gangwon area, the present status of export competitive power and the SWOT analysis of competitive power of the medical device industry in Gangwon area, and the strengthening methods of export competitive power of the medical device industry in Gangwon area. As the research method, the questionaire for the strengthening of export competitive power of the medical device industry in Gangwon area was carried out from August 13 to Otober 22, 2009. The worldwide medical device market in 2008 is estimated at USD 210.2 billion, with the United States being the largest market, followed closely by Japan and Western Europe. In 2006, the worldwide export amount of medical devices recorded USD 121.1 billion and the worldwide import amount of medical devices recorded USD 126.3 billion. As of the end of 2008, the number of Korea's medical device manufacturers expanded to 1,726. The production amount of Korea's medical device industry in 2008 recorded 2,525 billion won, and the domestic market volume of medical devices in 2008 recorded 3,618 billion won. Korea's export amount of medical devices in 2008 recorded USD 1,132 million and recorded a 9.67% growth compared to the previous year, and the import amount of medical devices recorded USD 2,123 million and recorded a 1.43% reduction compared to the previous year. As of the end of 2008, the number of Gangwon area's medical device manufacturers expanded to 81. The production amount of Gangwon area's medical industry in 2008 recorded 380 billion won, and Gangwon area's export amount of medical devices recorded USD 269 million and recorded a 0.25% reduction compared to the previous year, and the import amount of medical devices recorded USD 3 million and recorded a 39.63% reduction compared to the previous year. According to the result analysis of the questionaire for the strengthening of export competitive power of medical device industry in Gangwon area(August 13~October 22, 2009), the competing country of the export medical device is the United States being the highest ranking. Comparing to the collective competitive power level 100 of the competing country, the collective competitive level of the export medical device is 60 below and 70-80 below being the highest ranking. Comparing to the quality level 100 of the United States, EU and Japan, the quality level of the export medical device is 80-90 below being the highest ranking. Comparing to the design level 100 of the United States, EU and Japan, the design level of the export medical device is 90-100 below being the highest ranking. Comparing to the technology level 100 of the United States, EU and Japan, the technology level of the export medical device is 80-90 below being the highest ranking. According to the SWOT analysis of competitive power of medical device industry in Gangwon area, the strength is the abundant expert manpower of the medical device in Wonju area. The weakness is the fragility of the brand recognition of the medical device industry. The opportunity is the demand increase of the new medical device owing to the advanced age of population. The threat is the difficulty of entry into overseas market owing to the request of the new specification certification of the medical device. In order to strengthen the export competitive power of the medical device industry in Gangwon area, the following measures should be taken by the government, local self-government body, related organization and medical device industry : the development of new technology and design, the enhancement of brand recognition. the acquisition of the foreign specification certification, the building of overseas distribution channel and after sales service channel, the positive participation in overseas medical device exhibition and opening of medical device exhibition, the training of expert manpower, the strengthening of overseas marketing, and the application of FTA and the establishment of counter measures against FTA. In conclusion, the medical device industry in Gangwon area has the difficulty in the entry into the overseas market owing to the shortage of overseas marketing capability. Therefore, the government and local self-government body should make the intensive and systematical support for overseas marketing of the medical device industry. For the support of overseas marketing, the government and local self-government body should provide positively the support of expenses for the acquisition of foreign specification certification, the support of participation in the overseas medical device exhibition, the despatch of market development mission, the increase of the support amount for R&D investment fund, and the training of expert manpower of medical devices.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.237-237
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• 2015

The district of Marlborough has had more than its share of river management projects over the past 150 years, each one uniquely affecting the geomorphology and flood hazard of the Wairau Plains. A major early project was to block the Opawa distributary channel at Conders Bend. The Opawa distributary channel took a third and more of Wairau River floodwaters and was a major increasing threat to Blenheim. The blocking of the Opawa required the Wairau and Lower Wairau rivers to carry greater flood flows more often. Consequently the Lower Wairau River was breaking out of its stopbanks approximately every seven years. The idea of diverting flood waters at Tuamarina by providing a direct diversion to the sea through the beach ridges was conceptualised back around the 1920s however, limits on resources and machinery meant the mission of excavating this diversion didn't become feasible until the 1960s. In 1964 a 10 m wide pilot channel was cut from the sea to Tuamarina with an initial capacity of $700m^3/s$. It was expected that floods would eventually scour this 'Wairau Diversion' to its design channel width of 150 m. This did take many more years than initially thought but after approximately 50 years with a little mechanical assistance the Wairau Diversion reached an adequate capacity. Using the power of the river to erode the channel out to its design width and depth was a brilliant idea that saved many thousands of dollars in construction costs and it is somewhat ironic that it is that very same concept that is now being used to deal with the aggradation problem that the Wairau Diversion has caused. The introduction of the Wairau Diversion did provide some flood relief to the lower reaches of the river but unfortunately as the Diversion channel was eroding and enlarging the Lower Wairau River was aggrading and reducing in capacity due to its inability to pass its sediment load with reduced flood flows. It is estimated that approximately $2,000,000m^3$ of sediment was deposited on the bed of the Lower Wairau River in the time between the Diversion's introduction in 1964 and 2010, raising the Lower Wairau's bed upwards of 1.5m in some locations. A numerical morphological model (MIKE-11 ST) was used to assess a number of options which led to the decision and resource consent to construct an erodible (fuse plug) bank at the head of the Wairau Diversion to divert more frequent scouring-flows ($+400m^3/s$)down the Lower Wairau River. Full control gates were ruled out on the grounds of expense. The initial construction of the erodible bank followed in late 2009 with the bank's level at the fuse location set to overtop and begin washing out at a combined Wairau flow of $1,400m^3/s$ which avoids berm flooding in the Lower Wairau. In the three years since the erodible bank was first constructed the Wairau River has sustained 14 events with recorded flows at Tuamarina above $1,000m^3/s$ and three of events in excess of $2,500m^3/s$. These freshes and floods have resulted in washout and rebuild of the erodible bank eight times with a combined rebuild expenditure of $80,000. Marlborough District Council's Rivers & Drainage Department maintains a regular monitoring program for the bed of the Lower Wairau River, which consists of recurrently surveying a series of standard cross sections and estimating the mean bed level (MBL) at each section as well as an overall MBL change over time. A survey was carried out just prior to the installation of the erodible bank and another survey was carried out earlier this year. The results from this latest survey show for the first time since construction of the Wairau Diversion the Lower Wairau River is enlarging. It is estimated that the entire bed of the Lower Wairau has eroded down by an overall average of 60 mm since the introduction of the erodible bank which equates to a total volume of $260,000m^3$. At a cost of $$0.30/m^3$ this represents excellent value compared to mechanical dredging which would likely be in excess of $$10/m^3$. This confirms that the idea of using the river to enlarge the channel is again working for the Wairau River system and that in time nature's "excavator" will provide a channel capacity that will continue to meet design requirements.

• Journal of Astronomy and Space Sciences
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• 제22권3호
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• pp.329-352
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• 2005

자외선 영역에서 최대 세기를 보이는 라이먼 알파(121.6nm)선은 태양 채층과 전이영역의 방출선으로 지구 고층 대기 변화의 주요 원인이 되기 때문에, 태양연구에서 가장 중요한 파장대의 하나이다. 그렇지만, 이전의 라이먼 알파선의 관측은 콜로라도 대학 등 미국의 여러 대학들에서 탐사 로켓에 의해 수행된 단속적인 관측들뿐이었고, 여러 위성에 의한 관측들도 시간 분해능이 아주 떨어지는 장기 관측들뿐이었다. 그러므로 인공위성에 탑재되어 충분한 시간 분해능과 연속적인 관측이 충족될 수 있는 라이먼 알파선 태양망원경의 개발은 세계적으로도 중요한 과학적 의미를 갖고 있으며, 인공위성의 운영에 막대한 영향을 미치는 지구 고층 대기에 대한 태양 자외선 복사의 영향을 연구하기 위한 실용적인 목적도 갖고 있다. 이러한 배경에 의해 본 연구는 과학기술위성2호 탑재용 자외선 태양카메라(LIST: $Lyman-{\alpha}$ Imaging Solar Telescope)를 개발하기 위한 목적으로 system 규격결정이 이루어졌으며 광학계, 기계구조 및 전자회로의 예비 설계가 완성되었다. 또한 system requirements에 맞춰 광학계, 기계구조 및 전자회로의 예비 구조 설계가 완료되었으며 기계 구조해석 및 열해석, test plan 결정 및 verification test matrix 작성도 완료되었다. 부분별로는 상세설계가 완료되어 제작에 착수하였으며 본 탑재체의 데이터에 맞는 데이터 획득 시스템을 결정하기위한 기반 조사가 완료되었다. 과학적 운영을 위해서는 태양의 진공 자외선 복사의 연구 방향과 연구 현황 등 데이터를 수집하고, 수집된 자료로 태양에 대해 지속적인 연구가 이루어졌다 자외선 태양카메라 연구개발은 산업적인 파급효과가 큰 광학계의 설계와 비구면 광학계의 제작기술, 첨단 측광기의 기본을 이루는 CCD의 제어기술, 탑재체의 통제 제어 기술이 요구된다. 확보된 우주 탑재체 개발 기술과 결과물들은 본 사업에 적용되었던 시스템 관리 기법과 함께 향후 유사한 우주기술 사업에 이용될 수 있으며 과학적 시스템과 성과물들도 현재 정부가 지원하여 구축하고 있는 우주환경 감시 시스템에 이용될 수 있다.

• 벤처창업연구
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• 제14권1호
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• pp.187-198
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• 2019

성공적인 비즈니스를 위해서 지속가능성과 관련된 도전과 기회들을 이해하는 것이 중요하다. 기존의 비즈니스모델 캔버스는 사회에 미치는 장기적인 영향과 관계없이 '성공'으로 식별되는 비즈니스 모델을 만들 수 있다. 하지만 지속가능한 비즈니스모델에 대한 원칙과 지침이 추가되지 않으면 새로운 한계에 직면할 수 있다. 본 연구의 목적은 경제적인 미션뿐만 아니라 사회적, 환경적 미션을 함께 수행해야 하는 소셜벤처를 중심으로 지속가능한 비즈니스 모델 설계를 위한 도구들을 살펴보고 활용도를 모색하는 데 있다. 이러한 연구 목적을 달성하기 위해 소셜벤처 창업가들의 경영사례를 분석하여 경제적, 환경적, 사회적 세 가지 관점의 비즈니스 모델을 정립하여 지속가능성을 높일 수 있는 기회를 탐색했다. 본 연구는 기존 선행연구의 한계점을 극복하고자 TLBMC (Triple Layered Business Model Canvas)를 사용하여 소셜벤처가 지녀야할 경제적, 환경적, 사회적 관점으로 다양하게 분석하였다. 그 결과 다음과 같은 시사점을 가지고 있다. 첫째, 경제적 요소를 사회적, 환경적 요구와 연결 가능한 기회를 살펴보았다. 둘째, 소셜벤처의 특성인 환경적 사회적 관점을 실무에 활용 할 수 있음을 확인했다. 셋째, 소셜벤처 비즈니스 모델의 경험 자료를 구축했다. 본 연구는 질적연구의 특징인 참여자의 관점, 참여자의 의미, 참여자의 다양한 주관적 견해에 초점을 맞추어 진행하여, 도출된 전반적인 의미에 대해 연구자의 주장으로 결론이 마무리되는 사례연구로서의 한계를 가지고 있다. 그러나 본 연구의 새로운 접근법은 향후 지속가능한 성공을 위한 새로운 비즈니스 모델 설계의 기회를 제공하고 있다. 또한 실증연구를 위한 기초단계로서 소셜벤처 비즈니스 모델연구에 기초가 될 수 있을 것이다. 지속가능한 비즈니스의 기회를 이해하기 위해 향후 더 많은 사례연구와 개선된 도구에 대한 검증과 피드백에 관련된 연구가 계속 되어야 할 것이다.