• International Journal of Ocean System Engineering
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• 제2권3호
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• pp.139-150
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• 2012

This paper presents an improved guidance algorithm for autonomous underwater vehicles (AUV) in 3D space for generating smoother vehicle turn during the course change at the way-points. The way-point guidance by the line-of-sight (LOS) method has been modified for correcting the reference angles to achieve minimal calculation and smoother transition at the way-points. The algorithm has two phases in which the first phase brings the vehicle to converge to a distance threshold point on the line segment connecting the first two way-points and the next phase generates an angular path with smoother transition at the way-points. Then the desired angles are calculated from the reference and correction angles. The path points are regularly parameterized in the spherical coordinates and mapped to the Cartesian coordinates. The proposed algorithm is found to be simple and can be used for real time implementation. The details of the algorithm and simulation results are presented.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.155-160
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• 2003

For the weight reduction of vehicle body up to 20∼30% compared to the conventional monocoque steel body·.in-white, most automotive manufacturers have attempted to develop the aluminum intensive body-in-white using an aluminum space frame. In this paper, the crush tests and simulations for the aluminum extrusions filled with the structural from are performed to evaluate the collapse characteristics of that light weighted material. From these studies. the effectiveness of structural for is evaluated in improving automotive crashworthiness. In order to improve the improve energy absorption capability of the aluminum space frame body, safety design modifications are performed and analyzed based on the suggested collapse initiator concepts and on the application of the aluminum extrusions filled with structural foam. The effectiveness of these design concepts on the frontal and side impact characteristics of the aluminum intensive vehicle structure is investigated and summarized.

• 한국신뢰성학회지:신뢰성응용연구
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• 제4권2호
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• pp.105-119
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• 2004

Reliability program is essential to the development of space systems like launch vehicles and satellites, as they are non-repairable after launch and the failure of a launch vehicle resulted in catastrophic consequences for the mission. Foreign advanced space organizations have developed and implemented their own reliability management programs for launch vehicles from the conceptual design stage to the detail processes for the individual components, procedures and test reports. A study on the launch failures and the reliability analysis methods for one-shot devices contained in this paper will contribute to the reliability improvement for Korean launch vehicle and components.

• 시스템엔지니어링학술지
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• 제14권2호
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• pp.16-23
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• 2018

The intended system's function and performance can be assured through implementing the development process, the verification compliance against corresponding requirements, in accordance with the fundamental principle from the Systems Engineering. For the effective verification implementation, related core metadata should be selected and managed throughout the development life cycle. And these have to be included in the configuration document such as specification so that taking them as development baselines each phases if necessary. In this paper, associated case study results are introduced to establish the Requirements Verification Matrix (RVM) for the verification management on the space launch vehicle development program.

• 한국항공우주학회지
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• 제34권2호
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• pp.112-118
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• 2006

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.1023-1026
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• 2005

In the ubiquitous computing environment, an intelligent vehicle is defined as a sensor node with a capability of intelligence and communication in a wire and wireless network space. To make it real, a lot of problems should be addressed in the aspect of vehicle mobility, in-vehicle communication, common service platform and the connection of heterogeneous networks to provide a driver with several intelligent information services beyond the time and space. In this paper, we present an intelligent information system for managing in-vehicle sensor network and a vehicle gateway for connecting the external networks. The in-vehicle sensor network connected with several sensor nodes is used to collect sensor data and control the vehicle based on CAN protocol. Each sensor node is equipped with a reusable modular node architecture, which contains a common CAN stack, a message manager and an event handler. The vehicle gateway makes vehicle control and diagnosis from a remote host possible by connecting the in-vehicle sensor network with an external network. Specifically, it gives an access to the external mobile communication network such as CDMA. Some experiments was made to find out how long it takes to communicate between a vehicle's intelligent information system and an external server in the various environment. The results show that the average response time amounts to 776ms at fixed place, 707ms at rural area and 910ms at urban area.

• 항공우주시스템공학회지
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• 제10권4호
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• pp.59-66
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• 2016

1950-1960년 대 인도와 중국은 미국, 서방국가, 그리고 구소련에게서 받은 로켓 기술을 바탕으로 발사체 개발을 수월하게 이룰 수 있었다. MTCR이 출범한 1987년 이후, 1990년 대 초를 제외하고는 양국이 MTCR 체제 밖에 있었으며, 미국과의 주요 우주분야 협력 이력은 거의 없었다. 그러나 21세기 들어서며 인도는 미국과 우주협력 관계로 진입하고 미국의 비 상용 위성을 인도발사체를 이용한 발사가 가능하게 되었다. 반면 미국은 중국과의 우주발사체 협력은 물론 우주협력에 회의적이다. 본 논문에서는 인도와 중국 발사체에 적용된 미국의 미사일 비확산정책을 살펴보고 적용된 정책의 유사점과 상이점을 분석하여 우리나라 우주개발에 대한 시사점을 제시하고자 하였다.

• 한국환경과학회지
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• 제28권12호
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• pp.1133-1145
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• 2019

Successful launch requires state-of-the-art launch vehicle technology and constant test operations, However, the meteorological threat to the launch vehicle flight trajectory is also an important factor for launch success. Atmospheric stability above the Naro Space Center at the this time is very important, especially because the initial flight operation can determine the success of the launch. Moreover, during the flight of launch vehicle with rapid pressure and thrust into the atmosphere, convection activity in the atmosphere may create environmental conditions that cause severe weather threats such as thunderstorms. Hence, studies of atmospheric instability characteristics over the Naro Space Center are a necessary part of successful launch missions. Therefore, the main aims of this study were to (1) verify the atmospheric stability index and convection activity characteristics over the Naro Space Center using radiosonde data observed from 2007 to 2018 by the Naro Space Center, (2) analyze changes in the atmospheric stability index according to monthly and seasonal changes, and (3) assess how the calculated atmospheric stability index is related to actual thunderstorm occurrence using statistical analysis. Additionally, we aimed to investigate the atmospheric characteristics above the Naro Space Center through the distribution chart of the atmospheric stability index during summer, when convection activity is highest. Finally, we assessed the relationship between lightning occurrence and unstable atmospheric conditions, through predictability analysis performed using the lightning observation data of the Korea Meteorological Administration.

• International Journal of Aeronautical and Space Sciences
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• 제17권2호
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• pp.260-267
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• 2016

The design process of blended inlet body (BIB) for the preliminary design of a near-space high supersonic unmanned aerial vehicle (HSUAV) is presented. The mass flow rate and cowl area of inlet at a design point are obtained according to the cruise condition of the HSUAV. A mixed-compression axisymmetric supersonic inlet section with a fixed geometry reasonably matching the high supersonic cruise state is created by using the inviscid theory of aerodynamics. The inlet section is optimized and used as a baseline section for the BIB design. Three BIB concepts for the HSUAV are proposed, and their internal aerodynamic characteristics of inlet are evaluated using Euler computational fluid dynamics (Euler CFD) solver. The preferred concept is identified, in which the straight leading edge of the baseline HSUAV configuration is modified into the convex leading edge to accommodate the inlet and meet the requirements of the cowl area to capture the sufficient air flow. The total recovery of inlet for the preferred BIB concept and the aerodynamic characteristics of the modified HSUAV configuration are verified using Navier-Stokes computational fluid dynamics (NS CFD) solver. The validation indicates that the preferred BIB concept can meet both the requirements of the inlet and aerodynamic performance of the HSUAV.

• 한국가구학회지
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• 제23권4호
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• pp.467-478
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• 2012

Interurban railway is expanded by transportation that population can be centralism and cope efficiently in traffic jam by augmentation of vehicles in the city. Railroad chair departs in space of an existent simple rest and products that can raise human body standard and size by powerful engineering vicinity, quality of the material, psychological satisfaction etc. of users are developed steadily. Specially, study of space that can use various materials efficiently with bodily size government official because various of man and woman old and the young etc.. are using in occasion of the train is urgently required. Specially, railroad chair is a product that material and standard, structure, human body engineering, a finish etc. is studied variously. In the case of advanced nation, in case of design a chair operating time of railroad, is placed as all standards orderly and harmonious because is considered exercise dynamics etc.. and designs. The other side, in the case of our country, study expert of chair is short real and is depending on technological data of overseas railway vehicle. Chair for railroad must consider removal of short-range, long distance. That have to be consider to a lot of uncomfortable such as psychological satisfaction of user because the domestic Motor Companies are defining in fair development study and many researchers but the railroad chair company are not accumulated professional manpower and technological know-how. Railway vehicle can recognize that overseas visitors as well as native is important element as space that space is exposed internationally by product that Public personality which used cultural value is strong. Therefore, wish to plan valid spec relationship presentation of various design and specification, function etc.. and contribute to railroad chair development design process lists and analyzes van instances of railway vehicle chair of inside and outside of the country through this study.