• Transactions on Control, Automation and Systems Engineering
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• 제4권4호
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• pp.341-346
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• 2002

When a construction company builds a high structure. many piles should be driven into the ground by a hammer whose weight is 7,000 kg in order to make the ground under the structure safe and strong. So. it is essential to determine whether a pile is penetrated into the ground enough to support the weight of the structure since ground characteristics at different locations are different each other. This paper proposes a visual measurement system for pile rebound and penetration movement including vibration using a high-speed line-scan camera and a specially designed mark to recognize two-dimensional motion parameters of the mark using only a line-scan camera. A mark stacking white and black right-angled triangles is used for the measurement, and movement information for vertical distance, horizontal distance and rotational angle is determined simultaneously. Especially- by adopting a line-scan CCD camera whose line rate is 20 ㎑. the measurement performance of dynamic characteristics of the pile at impact instant is improved dramatically.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1993년도 봄 학술회 논문집
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• pp.59-62
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• 1993

In this study, various problems of ground vibration from rock blasting have been discussed, and field tests of rock blasting-ground vibration were carried out to find out the system of evaluation and control method for selecting blast design values and the rationale for the selection. Criterla of estimating structural response and damage caused by ground vibration from rock blasting are also discussed for the safety design of blast.

• 한국추진공학회지
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• 제21권1호
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• pp.91-97
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• 2017

한국형발사체 발사대시스템은 지상기계설비, 추진제공급설비, 발사관제설비 그리고 기반시설로 구성된다. 추진제공급설비의 구성품인 고압가스 공급시스템은 우주발사체 발사 운용에 필요한 고압가스를 저장하고 각 사용처에 공급하는 역할을 수행한다. 고압가스 공급시스템은 고압가스 저장부, 조정패널, 제어서브시스템 등으로 구성되며, 조정패널 중 자동패널은 제어기와 연동되어 원격으로 구동이 가능하도록 구축된다. 본 논문에서는 한국형발사체와 발사대시스템 지상설비의 특성을 고려하여 설계된 고압 가스 공급시스템에 대해 소개하고자 한다.

• 한국추진공학회지
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• 제19권1호
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• pp.98-110
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• 2015

최근에 우주비행체의 기동 및 자세제어 로직을 검증하기 위해 소형화 및 정밀화된 부품들을 사용하여 지상에서 시뮬레이터의 구동을 통해 검증하는 연구가 활발하게 진행되는 추세이다. 지상 환경에서 우주비행체 시뮬레이터의 기동 및 자세제어를 위해 일반적으로 구성이 간단하고 신뢰도가 높은 냉가스 추진시스템이 사용된다. 본 연구에서는 우주비행체 지상시뮬레이터의 냉가스 추진시스템 개념설계 결과로서 임무 요구조건에 부합하는 주요 설계 파라미터를 도출하였으며, 전체 시스템 구성을 위한 적절한 사양의 상용부품을 선정하였다.

• International Journal of Aeronautical and Space Sciences
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• 제13권4호
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• pp.484-490
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• 2012

This paper is devoted to investigate the feasibility of using a medium power ground-based laser to produce a torque on LEO satellites of various shapes. The laser intensity delivered to a satellite is calculated using a simple model of laser propagation in which a standard atmospheric condition and linear atmospheric interaction mechanism is assumed. The laser force is formulated using a geocentric equatorial system in which the Earth is an oblate spheroid. The torque is formulated for a cylindrical satellite, spherical satellites and for satellites of complex shape. The torque algorithm is implemented for some sun synchronous low Earth orbit cubesats. Based on satellites perigee height, the results demonstrate that laser torque affecting on a cubesat has a maximum value in the order of $10^{-9}$ which is comparable with that of solar radiation. However, it has a minimum value in the order of $10^{-10}$ which is comparable with that of gravity gradient. Moreover, the results clarify the dependency of the laser torque on the orbital eccentricity. As the orbit becomes more circular it will experience less torque. So, we can conclude that the ground based laser torque has a significant contribution on the low Earth orbit cubesats. It can be adjusted to obtain the required control torque and it can be used as an active attitude control system for cubesats.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.367-371
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• 2004

This paper describes development of automatic flight control system for an unmanned target drone which is operated by Korean army as for anti-air gun shooting training. Current target drone is operated by pilot control of on-board servo motor via remote control system. Automatic flight control system for the target drone greatly reduces work load of ground pilot and can increase application area of the drone. Most UAVs being operated now days use high-priced sensors as AHRS and IMU to measure the attitude, but those are costly. This paper introduces the development of low-cost automatic flight control system with low-cost sensors. The integrated automatic flight control system has been developed by integrating combining power module, switching module, monitoring module and RC receiver as an one module. The performance of automatic flight control system is verified by flight test.

• 한국산학기술학회논문지
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• 제10권2호
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• pp.256-263
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• 2009

한국철도공사에서는 기존선의 신호시스템을 지상의 ATS 시스템에 의한 신호 현시에 따라 운전자가 제한속도 이내로 열차를 운전하던 방식에서 지상의 발리스로부터 이동권한을 전송받아 차상신호시스템(ATP)에서 Speed Profile을 생성하여 운전하는 Bombardier Transport사의 ATP 시스템으로 개량하고 있다. 한국철도기술연구원에서는 기존선의 속도 향상을 위해 틸팅열차를 개발하여 10만 km 주행시험 중이며, 중앙선에 투입이 가시화되고 있다. 이러한 틸팅열차를 ATP 시스템에 의해 운전할 때 곡선구간에서 현재 제한되어지고 있는 곡선부 통과 속도를 증속하는 것이 쉽지 않은 형편이다. 따라서 향후 ATP 시스템의 국산화 개발이 이루어질 것을 대비하여 선행적으로 ATP 시스템의 핵심 기술인 선행열차에 따른 후행열차의 안전제동모델 및 열차간격제어 기술을 연구 개발할 필요성이 있다. 본 논문에서는 이를 위하여 발리스를 이용하는 ATP 시스템의 안전제동모델 및 열차간격제어 기술을 개발하고 그 성능을 시뮬레이션 하였다.

• Journal of Astronomy and Space Sciences
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• 제16권2호
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• pp.177-190
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• 1999

An absorbed heat-flux method for ground simulation of on-orbit thermal environment of satellite is addressed in this paper. For satellite ground test, high vacuum and extremely low temperature of deep space are achieved by space simulation chamber, while spatial environmental heating is simulated by employing the absorbed heat-flux method. The methodology is explained in detail with test requirement and setup implemented on a satellite. Developed heat-load control system is presented with an adjusted PID-control logic and the system schematic realized is shown. A practical and successful application of the heat simulation method to KOMPSAT(Korea Multi-purpose Satellite)thermal environmental test is demonstrated, finally.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.60-65
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• 2003

A new algorithm was developed to interpret joint orientations from a pair of images of the rock slope to overcome the limitation of photographing direction as in the parallel stereophotogrammetric system and to maximize the range of image measurement. This algorithm can be regarded as a modified multistage convergent photographing system. To determine camera parameters in the perspective projection equation that are the major elements in the photogrammetric technique, a new concept was developed by using three ground control points and single ground guide point. This method could be considered to be very simple when compared with other existing methods which use a number of ground control points and complicated analysis processes.

• 제어로봇시스템학회논문지
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• 제21권9호
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• pp.888-897
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• 2015

A flight capability to take a terrain following flight near the ground is required to reduce the probability that a fighter aircraft can be detected by foe's radar fence in the battlefield. The success rate for mission flight has increased by adopting TFS (Terrain Following System) to enable the modern advanced fighter to fly safely near the ground at the low altitude. This system has applied to the state-of-the-art fighter and bomber, such as B-1, F-111, F-16 E/F and F-15, since the research begins from 1960's. In this paper, the terrain following system and GCAS (Ground Collision Avoidance System) was developed, based on a digital database with UTAS's TERPRROM (TERrain PROfile Matching) equipment. This system calculates the relative location of the aircraft in the terrain database by using the aircraft status information provided by the radar altimeter and the INS (Inertial Navigation System), based on the digital terrain database loaded previously in the DTC (Data Transfer Cartridge), and figures out terrain features around. And, the system is a manual terrain following system which makes a steering command cue refer to flight path marker, on the HUD (Head Up Display), for vertical acceleration essential for terrain following flight and enables a pilot to follow it. The cue is based on the recognized terrain features and TCH (Target Clearance Height) set by a pilot in advance. The developed terrain following system was verified in the real-time pilot evaluation in FA-50 HQS (Handling Quality Simulator) environment.