• 한국항공우주학회지
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• 제43권10호
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• pp.936-942
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• 2015

국가위상 제고와 국내 발사체산업 발전에 따른 경제 발전을 위하여 우주발사서비스 시장진입은 필수적이다. 발사체 개발의 후발주자로써 시장에 효과적으로 진입하기 위해서는 시장의 트렌드를 정확하게 파악하고, 체계적인 시장진입전략을 수립하여야한다. 본 논문에서는 세계 우주발사서비스 시장의 3가지 핵심트렌드(고성능의 대형 우주발사체 수요 증가, 저가형 우주발사체 증가, Dual/Multi-Launch 증가)를 도출하고, 각 핵심트렌드에 대응하기 위한 전략의 우선순위를 쌍대비교분석법을 통해 평가하였다. 그 결과 모든 트렌드 하에서 발사체 신뢰성 확보 전략이 가장 중요하며, 고성능의 대형 우주발사체 수요 증가 트렌드 하에서는 정부 지원 전략이, 저가형 우주발사체 및 Dual/Multi-Launch 증가 트렌드 하에서는 가격 경쟁력 확보전략이 두 번째 우선순위를 보였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.847-851
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• 1996

In this study, in order to adapt various types of suspensions that is not possible for a passenger car, and to validate the effect of the design change of a suspension upon ride and handling characteristics of vehicle, the modular experimental vehicle, which makes possible to exchange suspension systems, has been designed and developed. In order to enable the assemblage between the modules, the experimental vehicle design is based on a space frame construction through finite element analysis. Moreover, the module frames and the brackets are designed are designed using three- dimensionalsolid modeler to check the interference between each part of a vehicle. The results of simulation and experiment are compared.

• International Journal of Automotive Technology
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• 제7권2호
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• pp.167-172
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• 2006

A design of controller for vehicle dynamic control(VDC) and its implementation on the real vehicle were introduced. The controller has been designed using a three-degrees-of-freedom(3DOF) yaw plane vehicle, and the control algorithm was implemented on the vehicle by control prototyping system dSPACE. A hybrid control algorithm, which makes full use of the advantages of robust and fuzzy control, was adopted in the control system. Field test results show that the performance of the vehicle handling dynamics with hybrid controller is improved obviously compared to that without VDC and with simple robust controller on skiddy roads(friction coefficients lower than 0.3).

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2002년도 춘계학술강연 및 발표대회
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• pp.7-7
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• 2002

Recently social demand to achieve low fuel consumption and clean emission requires the development of new generation vehicle beyond the conventional vehicle concept. In this point, new generation vehicle is newly designed as electric vehicle, hybrid electric vehicle, fuel cell electric vehicle or 3 liter car etc. In order to develop new generation vehicle, it is very important to develop new materials and process technologies now. In this paper these new technologies are presented focusing on weight reduction specially. Steel body can be achieved 20-25% weight reduction by adoption of high strength steel and new process technologies, i.e tailored blank and hydroforming. Aluminium body can be achieved 40-50% weigt down by use of all aluminium monocoque body or aluminium space frame with aluminium panel. Plasitic composite body can be achieved 30% weight reduction comparing with conventional steel body.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.79-85
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• 2001

The ocean is vital to life on earth providing needed resources, particularly for mankind Nowadays, space utilization of the ocean is burgeoning research field. In the shallow water, an underwater transportation utility for diver is an effective tool for the ocean space utilization, and a Diver Transport Vehicle(DTV) is one of those utilities. The project which started in summer of 2000 is supported by the Korea research Council of Public Science and Technology. The objective of the project is to develop design techniques for DTV integrating the available technologies of KRISO research divisions. In this, the development of DTV is introduced.

• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.1-7
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• 2016

The influence of boundary condition of the bodies with gas flows is one of the most important problems in high-altitude aerodynamics. In this paper presents the results of the calculation of aerodynamic characteristics of aerospace vehicle using Monte-Carlo method based on three different gas-surface interaction models - Maxwell model, Cercignani-Lampis-Lord (CLL) model and Lennard-Jones (LJ) potential. These models are very sensitive for force and moment coefficients of aerospace vehicle in the hypersonic free molecular flow. The models, method and results can be used for new generation aerospace vehicle design.

• 한국정밀공학회지
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• 제17권6호
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• pp.111-118
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• 2000

The design of reference trajectory with respect to drag acceleration is necessary to decelerate from hypersonic speed safely after atmosphere re-entry of space vehicle. The re-entry guidance design involves trajectory optimization, generation of a reference drag acceleration profile with the satisfaction of 6 trajectory constraints during the re-entry flight. This reference drag acceleration profile can be considered as the reference trajectory. The cost function is composed of the accumulated total heating on vehicle due to the reduction of weight. And a regularization is needed to prevent optimal drag profile from varying too fast and achieve realized trajectory. This paper shows the relations between velocity, drag acceleration and altitude in drag acceleration profile, and how to determine the reference trajectory.

• 한국항공우주학회지
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• 제35권2호
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• pp.171-176
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• 2007

이동체와의 통신은 항상 안테나가 이동체의 방향을 지향하고 있어야 한다. 본 연구에서는 안테나가 이동체를 지향하기 위해서 사용되는 방식중 이동체의 위치를 측정하여 이동체와 안테나 사이의 기하학적 위치관계로부터 안테나의 지향각을 결정하는 방법을 사용하였다. 안테나와 무인항공기에 각각 GPS를 설치하여 각각의 위치를 측정하고 계산된 지향각을 향하도록 안테나를 구동하였다. 안테나의 지향각과 일치시켜 설치한 카메라를 사용하여 무인항공기를 촬영하여 추적 안테나 시스템의 성능을 검증하였다

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.797-800
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• 2011

우주발사체에 있어서 추진기관 시스템은 가장 중요한 구성 요소이다. 액체 추진기관을 새로 개발한다고 할 때, 그 개발 수준을 평가하기 위해서는 적절한 시험 설비에서 수행되는 시스템 종합시험이 반드시 필요하다. 본 논문에서는 새로운 추진기관 시스템의 개발 인증을 위해 개발 단계별로 요구되는 시험의 종류와 반드시 확인해야 할 변수들을 검토 정리하였다.

• Interaction and multiscale mechanics
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• 제3권4호
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• pp.333-342
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• 2010

The Pseudo-Excitation Method (PEM) is applied to study the stochastic space vibration responses of train-bridge coupling system. Each vehicle is modeled as a four-wheel mass-spring-damper system with two layers of suspension system possessing 15 degrees-of- freedom. The bridge is modeled as a spatial beam element, and the track irregularity is assumed to be a uniform random process. The motion equations of the vehicle system are established based on the d'Alembertian principle, and the motion equations of the bridge system are established based on the Hamilton variational principle. Separate iteration is applied in the solution of equations. Comparisons with the Monte Carlo simulations show the effectiveness and satisfactory accuracy of the proposed method. The PSD of the 3-span simply-supported girder bridge responses, vehicle responses and wheel/rail forces are obtained. Based on the $3{\sigma}$ rule for Gaussian stochastic processes, the maximum responses of the coupling system are suggested.