• 시스템엔지니어링학술지
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• 제1권1호
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• pp.67-72
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• 2005

Design and optimization study has been performed to obtain a supersonic air.launching mission for the nanosat launcher. Given mission is to launch 10kg payload to target orbit of $700km{\times}700km$. Additional design constraints are imposed by the mother plane. After the required velocity is obtained, the stag ing optimization is carried out. Serial analyses for the propulsion system and aerodynamics are performed then, the rocket trajectory optimization has been carried out. After several mission design and optimization iterations, the optimized mission which satisfies the mission target is obtained. Total weight of the three-staged air-launching rocket is 1231.4kg and the payload weight is 10 kg.

• 한국군사과학기술학회지
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• 제15권4호
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• pp.398-403
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• 2012

This paper describes about the analysis of firing rebounding force exerted on the launching system supporting structure. The measured high pressure data at the launching tube is used as external force. The maximum firing rebounding force was occurred when the snubber of inner structure contacts the surface of wall in launching tube.

• 한국의류학회지
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• 제24권7호
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• pp.1056-1064
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• 2000

The aim of this paper was to look at distribution intensity of casual wear brand before and after IMF Management System. It also provides the guide to distribution design and reinforces the strategy of the brand of it. Since the firm especially in casual wear industry recently has had difficulty in how to decide and to select the distribution numbers in the domestic market. Based on the data in‘98 Korea Fashion Guide’and ‘Korean Fashion Brand Annual’, 78 brands had been analyzed with percentage, multiple regression. The results were as follows: In general, the lower the price of the product is and the higher the total sale is, the more intensive the distribution of the casual wear brand is before and after IMF Management System. The longer the launching period is, the more intensive the distribution of the casual wear industry is after IMF Management System. Besides, there is difference between the brand origins in the distribution intensity. In addition, two brand types were classified and tested. The distribution intensity of jean casual wear and uni-sex casual wear have related to the price after IMF and the total sale before and after IMF Management System while there is no relationship with the launching period before and after IMF Management System. The distribution intensity of the domestic brand have related to the price, and the total sale, while the foreign brand has a relationship with the total sale before and after IMF Management System. The foreign brand has related only to launching period after IMF Management System.

• 한국항공우주학회지
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• 제33권12호
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• pp.83-91
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• 2005

최근 활발한 연구가 진행 중인 공중발사 방식은 극소형 위성을 매우 저렴한 비용으로 발사할 수 있는 효율적인 방법이다. 본 연구에서는 비교적 단순한 임무를 수행할 수 있는 나노 위성을 공중발사 방식을 이용하여 원 궤도에 올릴 수 있는 공중발사 로켓 시스템설계와 각 단별 계통 설계를 수행하였다. 이를 위하여 공중발사 로켓 시스템의 WBS와 각 계통별 작동개념도를 정립하였고, 이를 바탕으로 시스템 세부형상과 DMU를 구현하였다.

• 한국자동차공학회논문집
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• 제7권7호
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• pp.157-166
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• 1999

This paper describes the launching characteristics of a passenger car using a Push-Belt type Continuously Variable Transmission(CVT) which equipped a wet type multi-plate clutch asa starting device and a solid flywheel with a torsional damper for a torsional coupling device. To reduce the torsional vibration of the drive-line , some torsional coupling devices were used for the passenger car equipped CVT having the clutch as a starting device especially . In this study, we developed the computer simulation program to investigate the launching characteristics of a passenger car equipped CVT using the mathematical models of this system. For the mathematical models of the vehicle, the CVT, the we type multi-plate clutch and the torsional damper, we obtained the specification and the necessary data through the reverse engineering of those. For the verification of our analysis, we performed the test of prototype car with different throttle positions at road and dynamometer. The launching characteristics of a passenger car considered here an acceleration performance and an ascending performance.

• Structural Engineering and Mechanics
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• 제18권4호
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• pp.429-440
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• 2004

Remotely Operated Vehicle of 6000-meters is a new conceptual equipment made to replace the manned systems for investigating the deep-sea environment, and all of the ROV systems in operational condition strongly depend on the connecting cables. In this point of view dynamics of the ROV cable system is very important for operational and safety aspects as a cable generally encounters great tension. Researches have been executed on this problem, and most of papers have been mainly focused on the operational condition of ROV system in deep sea. This paper presents the dynamic cable response analysis during ROV launching condition rather than the operational one in order to provide the design guide of a ROV cable system in this circumstance, considering the coupling effects between cable and wave-induced ship motion. To obtain the variations of cable tensions during a ROV launching, a pre-stressed harmonic response analysis was carried out. Wave-induced tensions of the cable during ROV launching were obtained in real sea states using FE modeling, and the basic design guide of a ROV cable system was obtained.

• 한국강구조학회 논문집
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• 제19권6호
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• pp.681-693
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• 2007

본 연구에서는 연속거더교량에 적용되고 있는 가설공법을 이중합성 박스거더교에 적용하여 발생 단면력을 검토하고, 적용성 측면에서 개선사항을 도출하고자 하였다. 하부콘크리트의 타설높이 및 타설범위는 각각 이중합성단면에 대한 소성모멘트 및 부모멘트영역에 의하여 결정되었다. 검토 가설공법은 일반적인 가설조건을 고려하여 크레인 가설공법, 켄틸레버 가설공법, 압출가설공법 등을 대상으로 하였으며, 이중합성 박스거더 가설 전의 하부콘크리트 타설유무에 따라 두가지의 경우로 구분하여 각각 시공중에 발생하는 단면력을 검토하였다. 또한, 압출가설공법 적용시의 단면력 저감방안으로 압출노즈에 의한 가설방안을 검토하였으며, 가설거더에 대한 압출노즈의 길이비, 단위중량비, 휨강성비 등의 변화에 따른 단면력의 저감정도를 검토하였다. 압출노즈에 의한 가설공법은 이중합성 박스거더교량에도 유효하게 적용될 수 있음을 확인하였다.

• 한국기계가공학회지
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• 제17권2호
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• pp.109-117
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• 2018

The experimental results are presented of an autonomous flight algorithm of a foldable quadcopter with airdrop launching functions. A foldable wing structure enabled the quadcopter to be inserted into a rocket container with limited space. The foldable quadcopter was then separated from the rocket in the air. The flight pattern was tracked using a global positioning system (GPS) with various sensors, including an inertial measurement unit (IMU) module until a designated target position was reached. Extensive field tests were conducted through an international rocket competition, ARLISS 2017, which was held in Black Rock Desert, Nevada, USA. The flight trajectory record of the experiments is stored in electrically erasable programmable read-only memory (EEPROM) embedded in the main control unit. The flight record confirmed that the quadcopter successfully separated from the rocket, executed flight toward the target for a certain length of time, and stably landed on the ground.

• 대한토목학회논문집
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• 제12권4호
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• pp.1-10
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• 1992

프리스트레스트 콘크리트 교량을 압출공법으로 가설하는 과정에서는 구조계가 계속하여 변하므로 교량의 주형에는 사용하중 상태에서와는 상이한 교번 단면력이 발생하게 된다. 이러한 단면력의 크기는 경간 길이, 추진코의 길이 및 강성등에 영향을 받게 된다. 본 논문에서는 많은 예제를 해석하여 이러한 요소들이 주형에 발생하는 최대 단면력에 미치는 영향을 연구하였다. 주프로그램의 복잡한 입력작업을 쉽게 처리할 수 있는 선처리 프로그램과 더불어 주형압출시 변화되는 구조계의 다단계 해석을 수행하여 최종적인 결과를 종합 출력할 수 있는 전산프로그램을 개발하였다. 압출공법으로 시공되는 박스거더교를 대상으로 하여 여러 가지 경간길이에 대한 구조해석을 수행한 결과로부터 경간 길이에 따른 최적 추진코길이와 강성비의 상호 관계를 제안하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.575-580
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• 2007

As the volume of traffic in southern part of the republic of Korea grew, expansion of transportation was required. In that purpose, the railway between Samnangjin and Gwangyang is being extended to a double-track line. This construction includes Nakdong bridge located across Nakdong river. This truss bridge is constructed in incremental launching method (ILM) and composed of two sections, straight line and curved one. Bridge construction in the method goes with the shift of roller supports which results in the change of structural system. To accomplish safe construction, the measurement during the whole launching stages. The locations of member in severe condition and the corresponding response values were estimated through the preliminary construction stage analysis. Based on the analysis, the measurement during construction was planned. Several sensors and measurement devices were installed at appropriate locations. During the whole launching stages, the measurement was performed and the corresponding data were monitored and stored in real time. The comparison of the responses from the analysis and the measurement showed no indication of yielding of the structural members. Consequently, the construction of Nakdong bridge was concluded to be relevant.