• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1461-1466
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• 2004

Recently Domestic EMU's on board signal systems are gradually changed form Cab signal(Fix Block) to Distance-to-go. Interfaces with on board signal system, TCMS Redundancy structure is mainly required. This paper suggest Manaul/Automatic Driving based on TCMS-ATC interface and design of backup system which is operated by Stan-by Computer when one of it's Local Interface Unit(LIU) is out of oder. For the purpose of Precision Train Stop, Distance-to-go signal system require accuracy speed. Free-axle structure is required for this system This paper suggest Free-axle braking system that lack of brake-force is compensated by the distributed brake-force using TCMS. And one of braking system has out of order, compensation of brake-force for Free-axle system. Then we prove our design to Complete Car Test

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.181-183
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• 2002

The accurate permeability for preform is critical to model and design the impregnation of fluid resin in the composite manufacturing process. In this study, the in-plane and transverse permeability for a woven fabric are predicted numerically through the coupled flow model which combines microscopic with macroscopic flow. The microscopic and macroscopic flow which are flows within the micro-unit and macro-unit cell, respectively, are calculated by using 3-D CVFEM(control volume finite element method). To avoid checker-board pressure field and improve the efficiency on numerical computation, A new interpolation function for velocity is proposed on the basis of analytic solutions. The permeability of plain woven fabric is measured through unidirectional flow experiment and compared with the permeability calculated numerically. Based on the good agreement of the results, the relationships between the permeability and the structures of preform such as the fiber volume fraction and stacking effect can be understood. The reverse and the simple stacking are taken in account. Unlike past literatures, this study is based on more realistic unit cell and the improved prediction of permeability can be achieved. It is observed that in-plane flow is more dominant than transverse flow in the real flow through preform and the stacking effect of multi-layered preform is negligible. Consequently, the proposed coupled flow model can be applied to modeling of real composite materials processing.

• Ocean and Polar Research
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• 제35권1호
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• pp.15-26
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• 2013

The toxic, Harmful Algal Blooms (HABs) caused by the Cochlodinium polykrikoides have a serious impact on the coastal waters of Korea. In this study, the acoustic detection system was developed for rapid HABs detection, based on the acoustic backscattering properties of the C. polykrikoides. The developed system was mainly composed of a pulser-receiver board, a signal processor board, a control board, a network board, a power board, ultrasonic sensors (3.5 and 5.0 MHz), an environmental sensor, GPS, and a land-based control unit. To evaluate the performance of the system, a trail was done at a laboratory, and two in situ trials were conducted: (1) when there was no red tide, and (2) when there was red tide. In the laboratory evaluation, the system performed well in accordance with the number of C. polykrikoides in the received level. Second, under the condition when there was no red tide in the field, there was a good correlation between the acoustic data and sampling data. Finally, under the condition when there was red tide in the field, the system successfully worked at various densities in accordance with the number of C. polykrikoides, and the results corresponded with the sampling data and monitoring result of NFRDI (National Fisheries Research & Development Institute). From the laboratory and field evaluations, the developed acoustic detection system for early detecting HABs has demonstrated that it could be a significant system to monitor the occurrence of HABs in coastal regions.

• 한국항행학회논문지
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• 제23권5호
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• pp.460-465
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• 2019

본 연구에서는 항법정보 산출용 컴퓨터에 탑재되는 단일보드컴퓨터를 대상으로 야전 운용간 발생한 전기적 고장현상에 대하여 구조해석 관점에서 해소방안을 도출하고자 하였다. 특성요인도 분석을 통해 단일보드컴퓨터의 구조적인 문제로 중앙처리장치 기판에 크랙이 발생한 것을 확인할 수 있었고, 크랙발생 부위에 가해진 물리적인 영향으로 인해 통신기능 수행이 불가해지면서 동시에 부팅이 불가한 현상이 나타난 것으로 확인되었다. 이에 대하여 크랙현상을 유발시키는 과도응력의 위치를 찾고자 구조해석을 수행하였다. 구조해석을 통해 응력집중현상이 발생하는 부위를 확인할 수 있었고, 이를 해소시키기 위해 과도응력의 원인이 되는 부품과 구조물을 변경하는 개선방안을 수립하였다. 개선방안에 대한 검증은 구조해석을 통해 개선 전과 후의 구조물에 작용하는 응력분포를 비교하여 응력의 감소정도를 보였다. 추가적으로, 열 해석을 통해 부품 및 구조물 변경으로 인한 방열기능 유지여부를 확인하였고, 개선방안을 적용한 실 장비의 방열판 온도를 측정함으로써 실제 장비의 방열 영향성을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.439-439
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• 2000

In this paper, the relationship among the vertical acceleration, measuring points and walking patterns is analyzed. To measure acceleration, the acceleration measurement unit and communication board is constructed. It uses MEMS accelerometer ADXL-202 that detects 2-axis acceleration simultaneously. It is shown by the experiment test that the walking pattern is recognized and walking step is detected at easy when acceleration measurement unit is mounted on leg.. This results can be directly utilized in designing the personal navigation system with low-cost inertial sensor.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.156-159
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• 2001

Recently, side scan sonar system has been developed and operated to survey cable laying, sunken bodies, geometry of sea bottom and so on. It uses the acoustic signals, which are emitted from two transducer arrays, left and right sides, to get geometric information of the specified area. This system consists of transceiver board, towed body, deck unit and GPS receiver. The transceiver board, nested in a watertight canister, controls the transmitting and receiving of the acoustic pulses from transducer arrays. After receiving the scattered signals, it processes BP(Band Pass) filtering, AGC(Automatic Gain Control), TVG(Time Varying Gain) and Heterodyne. The deck init has the signal processing part, A/D converter, power supplier, and real-time monitoring part. The towed body has been designed to satisfy the optimal hydrodynamic behavior during towing, In this paper, brief introductions on the design theory of transceiving part and some results from the field which have been operated recently will be introduced.

• 한국항해학회지
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• 제24권5호
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• pp.435-441
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• 2000

This paper deals with the development of RACOM(Radar Signal Detecting ＆ Processing Computer). RACOM is a radar display system specially designed for radar scan conversion, signal processing and PCI radar image display. RACOM contains two components； i )RSP(Radar Signal Processor) board which is a PCI based board for receiving video, trigger, heading & bearing signals from radar scanner ＆ tranceiver units and processing these signals to generate high resolution radar image, and ⅱ）Applications which perform ordinary radar display functions such as EBL, VRM and so on. Since RACOM is designed to meet a wide variety of specifications(type of output signal from tranceiver unit), to record radar images and to distribute those images in real time to everywhere in a networked environment, it can be applicable to AIS(Automatic Identification System) and VDR(Voyage Data Recorder).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.110-114
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• 1995

This paper presents the on-board attitude determination algorithm for LEO (Low Earth Orbit) three-axis stabilized spacecraft. Two advanced star trackers and a three-axis Inertial Reference Unit (IRU) are assumed to be attitude sensors. The gyro in the IRU provides a direct measurement of the attitude rates. However, the attitude estimation error increases with time due to the gyro drift and noise. An update filter with measurements of star trackers and/or sun sensor is designed to update these gyro drift bias and to compensate the attitude error. Kalman Filter is adapted for the on-board update filter algorithm. Simulation results will be presented to investigate the attitude pointing performance.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1093-1095
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• 2003

MSC(Multi-Spectral Camera) system is a remote sensing instrument to obtain high resolution ground image. MSC system includes main control unit, called SBC(Single Board Computer). SBC controls all the sub-units of MSC system and communicates with spacecraft bus. The software developed for SBC should be reliable and autonomous to support various kinds of imaging missions. It is being developed using VxWorks real-time operating system to manage all tasks for all units efficiently. In this paper, the characteristics of the embedded software on the MSC system will be presented. It covers the hardware related characteristics like the BSP(Board Support Package), device driver and code patch mechanism.

• 한국산학기술학회논문지
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• 제10권5호
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• pp.935-941
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• 2009

본 논문에서는 철도의 운영효율을 향상시킬 수 있는 무선통신에 기반을 둔 열차제어기술에 대해 연구하였다. 현재 국내에서 사용되고 있는 신호시스템은 궤도회로 기반의 열차제어시스템으로서 열차의 이동성과 안정성을 고려하여 사용한 기술이다. 최근의 세계적 추세는 열차간격을 고밀도로 제어하기 위해 새로운 패러다임으로 떠오르고 있는 무선통신기반 열차제어시스템이다. 국내에서도 이에 대한 기술 확보가 요구되며, 이에 따른 무선통신기반 열차제어시스템의 연구개발을 추진하였다. 본 논문에서는 열차제어시스템의 구성 중 핵심적인 요소인 차상제어장치를 개발하였고, 이를 수도권 광역전철중의 하나인 분당선의 전동차에 설치하여 시험한 결과를 설명하고 있다.