• 한국항공우주학회지
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• 제36권9호
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• pp.874-883
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• 2008

본 논문에서는 위성발사체의 폐루프 유도방식중 하나인 Powered Explicit Guidance에 대해서 연구하였다. 반복계산 과정이 없도록 변형시킨 알고리듬을 사용했으며, 추력변화가 큰 엔진 모델에 적용가능 하도록 단일 목표궤도에 대한 알고리듬에 대해서 기술하였다. 정상 및 비정상 비행조건에 대해서 6-자유도 컴퓨터 모의시험을 통해 얻어진 유도 알고리듬의 궤도 투입 정밀도 분석을 하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.419-424
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• 1991

In this paper, a fuel minimizing closed loop explicit inertial guidance algorithm for the orbit injection of a rocket is developed. In this formulation, the fuel burning rate and magnitude of thrust are assumed constant, and the motion of a rocket is assumed to be subject to the average inverse-square gravity, but with negligible atmospheric effects. The optimum thrust angle for obtaining the given velocity vector in the shortest time with minimizing fuel consumption is first determined, and then the additive thrust angle for targeting the final position vectors is determined by using Pontryagin's Maximum Principle. To establish the real time processing, many algorithms of the onboard guidance software are simplified. Simulations for the explicit guidance algorithm, for the 2nd-stage flight of the N-1 rocket, are carried out. The results show that the guidance algorithm works well in the presence of the maximum .+-.10 % initial velocity and altitude error. The effects of the guidance cycle time is also examined.

• 한국안전학회지
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• 제29권5호
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• pp.104-109
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• 2014

More than 76% of occupational accidents occur in small and medium sized enterprises(SME) employing less than 50 workers, due to the lack of safety and health systems, and carelessness of workers and owners. Timely Technical Guidance(TTG) project of Korea Occupational Safety & Heath Agency(KOSHA) for SME was initiated to analyze and inform accident causes just after accidents occur. Improvement direction of TTG project is suggested through situation and performance analysis on TTG services conducted in 2012. KOSHA provided TTS services on 15,571 SMEs(suffering at least one accident in 2012), through which the working day losses from recurrence resulted in 19.0%p, 14.5%p and 31.3%p decreases in manufacturing, services and construction businesses, respectively.

• 한국가정과학회지
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• 제9권4호
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• pp.55-66
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• 2006

The purpose of this study was to identify the effect on the evaluation or a female teachers' role-performance based on appearance according to backgrounds of students and their parents. For this study, data was collected between October 19 and 29, 2005 by means of a questionnaire designed to gauge a subject's evaluation of a teacher's abilities in learning guidance, living guidance, and human relations. The researchers selected two middle schools and four high schools in the city of Gwang-ju. The 398 surveys completed were analyzed using factor analysis, one-way ANOVA, Duncan's multiple range test, t-test and descriptive statistics. According to the study, the evaluation of a female teacher's abilities varies with the backgrounds of both students and their parents. Among the students tested perceptions were affected by gender, grade level and type of school attended. For mothers there were differences based on age, occupation and family income.

• 한국항공우주학회지
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• 제50권10호
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• pp.709-716
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• 2022

본 논문에서는 IUS (Inertial Upper Stage)에 사용된 Gamma 유도 방식을 상단이 고체모터로 구성된 위성발사체 유도를 위해 적용해 보았다. 알고리듬의 수렴성 및 고체모터의 속도 오차 보상을 위해 RCS(Reaction Control System)가 최상단 연소 종료 후 작동하는 것으로 두었다. 알고리듬 계산 과정 중 최종 궤도 투입 오차 예측을 위한 적분과정을 Keplerian 궤적으로 단순화함으로써 수치 적분과정이 없도록 알고리듬을 구성하였다. 유도 알고리듬 평가를 위해 비공칭 비행 조건에 대한 3-DOF 컴퓨터 시뮬레이션을 수행해 주어진 상단 유도 방식은 개루프 명령을 적용한 경우 대비 궤도 투입 오차를 줄일 수 있음을 보였다.

• 한국정밀공학회지
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• 제9권1호
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• pp.53-65
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• 1992

For improving the performance of maglev systems with a combined lift and guidance, it is suggested that the multivariable control systems and a secondary suspension should be added. The former is required to reject both track irregularities in vertical disturbances and wind gusts in lateral disturbances, and the latter to guarantee passengers against an unsatisfied criteria in ride quality. In this paper, bond graph model for the study of nonlinear dynamics of maglev systems with a combined lift and guidance is presented briefly. And, the secondary suspension is analyzed to understand the role of stiffness and damping factors in passive devices. Finally, LQG/LTR mulitivariable control systems are designed for the overall maglev systems with and without secondary suspension, and then the system performances in these two cases are evaluated.

• KIEAE Journal
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• 제4권2호
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• pp.19-27
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• 2004

The importance of Building Remodeling as a means to create an architectural environment capable of responding to the social, economic changes has increased more than ever. And it has become necessary to consider Environmental performance in Building remodeling. Consideration of converting buildings into Environment-Friendly Remodeling of Office Buildings makes more and more increased in our construction compatibility. This Study is intended to increase the designer' recognition of Environmental Performance Improvement in the feasibility analysis and schematic design of Office Building Remodeling and to provide Planning Data and Guidance. In this context, this study is focused on the "planning Guidance for Environmental Friendly Remodeling". Through this study, the flow of Environmental Design and Construction is elevated reaching the level in developed country.

• 설비공학논문집
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• 제22권10호
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• pp.672-678
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• 2010

The purpose of this study is to develop a stacking guidance system (SGS) of containers in the mobile harbor (MH). A mobile harbor is a floating structure especially designed for loading and unloading containers from and to a large container ship. A novel stacking guidance system was proposed for unloading the container in an effective way against possible vibrations of the floating body. The guidance system works as an aid for loading containers with a wider opening for easier stacking of a container into a moving storage cell due to waves. In order to determine the most effective inclination angle of the cell-guide, this study performed the dynamic analysis of the SGS equipped in the MH subject to fluctuations of the sea. The motions of the guidance system and a container loaded were calculated using ADAMS. The simulation results of the contact force between the two rigid bodies showed that a desirable angle of the cell-guide should be around 20 degrees from the vertical. This proposed SGS can considerably reduce the loading and unloading time, and will enhance the performance of the MH.

• 한국건설관리학회논문집
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• 제21권1호
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• pp.78-86
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• 2020

도저는 고가의 건설장비로서 건설토공현장 정지작업에서 커다란 영향을 가져온다. 이러한 중요성에 따라서 머신 가이던스 시스템이 도저에 적용되어 토공 정지작업의 성과를 올리기 위한 노력이 진행되고 있다. 머신 가이던스 시스템은 정지작업 시 장비기사에게 정지작업에 필요한 굴삭깊이, 경사각도 등 정보를 제공하며, 장비기사는 제공되는 정보를 이용하여 측량기사의 도움을 최소화 하면서 정지작업을 진행할 수 있다. 이와 같이 머신 가이던스 시스템은 장비기사가 계획도면 상의 계획고에 맞추어 정지작업을 수행할 수 있도록 돕는 기능을 제공한다. 본 논문의 목적은 머신 가이던스 시스템이 기존 토공 정지작업과 비교하여 토공 정지작업에 가져오는 성과향상을 분석하는 것이다. 성과분석은 1) 생산성과 2) 정확도 2가지 관점에서 수행됐다. 여기서 생산성은 단위시간에 도출되는 작업량을 나타내며, 정확도는 계획도면에서 요구하는 계획고에서 벗어나는 정도를 나타낸다. 본 연구목적을 달성하기 위해 도저 머신 가이던스 시스템을 테스트 현장에 적용했으며, 적용결과 머신 가이던스 시스템이 전통적인 방법과 비교하여 생산성의 경우 46.59%, 정확도의 경우 46.96%만큼 증가되는 성과향상을 확인할 수 있었다.

• 전기학회논문지
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• 제57권11호
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• pp.2074-2079
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• 2008

This paper presents a software toolbox with $Matlab^{(R)}$ developed for the various performance analysis of an automatic guidance system of the Bimodal Tram. The Bimodal Tram is a new kind of transportation vehicle which could be an all-wheel steered multiple-articulated vehicle. This vehicle has to be equipped with an automatic guidance, traction/braking, and docking system, In the stage of developing such a system, its validities and performances should be verified under various operation conditions. For the purpose of doing these things through simulation, this toolbox has been developed and demonstrated well by applying it to the KRRI model.