• International Journal of Control, Automation, and Systems
• /
• 제6권5호
• /
• pp.746-754
• /
• 2008

This paper proposes a method to detect calibration patterns for accurate camera calibration under complicated backgrounds and uneven lighting conditions of industrial fields. Required to measure object dimensions, the preprocessing of camera calibration must be able to extract calibration points from a calibration pattern. However, industrial fields for visual inspection rarely provide the proper lighting conditions for camera calibration of a measurement system. In this paper, a probabilistic criterion is proposed to detect a local set of calibration points, which would guide the extraction of other calibration points in a cluttered background under irregular lighting conditions. If only a local part of the calibration pattern can be seen, input data can be extracted for camera calibration. In an experiment using real images, we verified that the method can be applied to camera calibration for poor quality images obtained under uneven illumination and cluttered background.

• Corrosion Science and Technology
• /
• 제13권4호
• /
• pp.139-144
• /
• 2014

In corrosion-sensitive area of exsisting unpainted weathering steel bridge with closed box girder structure. there are some serious local corrosion problems because of rain water or dew water which can not be solved by conventional maintenance method. These problems must be technically controled because of the influence on the safety of bridge. This study is the first stage of developing the economic corrosion control manual for these local corrosion problems. Through the injecting experiment of tar sealant into the crevice of mock-up equipment, it was proofed that the corrosive sealant can be useful to corrosion control at crevice of corrosion sensitive area.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
• /
• pp.327-330
• /
• 2008

This paper presents monitoring system for 750kW-class DFIG wind turbine generator system and an architecture for applying standardized communication, IEC61400-25. Monitoring and control system is consists of wind turbine PLC, Local and Remote I/O Server, HMI. and Web-server. Proposed System has been demonstrated in Daegi-ri, Kangwon-do, which aims to test local and/or remote monitoring and control system and evaluate the performance of 750kW-class WTS. Finally we described the design of logical nodes and services based on IEC61400-25 and its application scheme.

• 한국가시화정보학회지
• /
• 제4권1호
• /
• pp.31-40
• /
• 2006

In this study a newly designed electro-osmotic micro-mixer is proposed. This study is composed of a channel and metal electrodes attached locally on the side wall surface ultimately to control the mixing effect. To obtain the flow patterns, numerical computation was performed by using a commercial code, CFD-ACE. The fluid-flow solutions are the cast into studying the characteristics of stirring in terms of the mixing index. It was shown that the local control of the electric potential can indeed contribute to the enhancement of mixing effect.

• 한국항행학회논문지
• /
• 제3권2호
• /
• pp.120-131
• /
• 1999

마그네트론을 이용하여 송신 펄스를 발생하는 레이다에서 위상을 측정하기 위해서는 송신주파수의 변화에 대해서도 안정된 중간주파수를 발생할 수 있도록 STALO(Stable Local Oscillator)의 주파수를 조정하여야 한다. 레이다 수신기의 AFC(Automatic Frequency control) 회로는 마그네트론에서 발생하는 송신주파수와 STALO의 국부발진주파수를 비교하여 일정한 중간주파수가 발생하도록 STALO 주파수를 제어한다. 본 논문에서는 안정된 중간주파수를 발생하기 위한 AFC 회로를 설계, 제작하였으며, 주파수 변화를 검출하여 비교하는 아날로그 부분과 STALO에 주파수 제어신호를 공급하는 디지털 부분을 개발하였다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
• /
• pp.707-711
• /
• 2004

We analyze the information level of local small and medium business in the base of Nolan's growth stage model. To estimate information level we do separate level analysis for six sections and integrated total level analysis. After analyzing information level of business, we focus on the factors of this result to understand the most influential environments. The local business we were studying are the third stage-control stage. But Organization of information department and Planning and control of information are the second stage. The number of computer system application field is very related to information level. We present the critical factors of information level of small and medium business.

• International Journal of Control, Automation, and Systems
• /
• 제4권4호
• /
• pp.456-465
• /
• 2006

The problem of recursive filtering far linear discrete-time systems with uncertainties is considered. A new suboptimal filtering algorithm is herein proposed. It is based on the fusion formula, which represents an optimal mean-square linear combination of local Kalman estimates with weights depending on cross-covariances between local filtering errors. In contrast to the optimal weights, the suboptimal weights do not depend on current measurements, and thus the proposed algorithm can easily be implemented in real-time. High accuracy and efficiency of the suboptimal filtering algorithm are demonstrated on the following examples: damper harmonic oscillator motion and vehicle motion constrained to a plane.

• International Journal of Control, Automation, and Systems
• /
• 제5권5호
• /
• pp.577-583
• /
• 2007

Simultaneous Localization and Mapping (SLAM) is the process of building a map of an unknown environment and simultaneously localizing a robot relative to this map. SLAM is very important for the indoor navigation of a mobile robot and much research has been conducted on this subject. Although feature-based SLAM using an Extended Kalman Filter (EKF) is widely used, it has shortcomings in that the computational complexity grows in proportion to the square of the number of features. This prohibits EKF-SLAM from operating in real time and makes it unfeasible in large environments where many features exist. This paper presents an algorithm which reduces the computational complexity of EKF-SLAM by using topological information (TI) extracted through a thinning process. The global map can be divided into local areas using the nodes of a thinning-based topological map. SLAM is then performed in local instead of global areas. Experimental results for various environments show that the performance and efficiency of the proposed EKF-SLAM/TI scheme are excellent.

• 한국통신학회논문지
• /
• 제11권6호
• /
• pp.402-410
• /
• 1986

IEEE 802 Local Area Network(LAN) 기준 모델의 Media Access Control(MAC)방식에서 CSMA/CD, 토큰링, 토큰 버스방식을 포함하며, LAN성능의 척도인 Throughput에 영향을 주는 파라미터는 채널의 길이, 전송 속도, 패킷의 크기 및 스테이션 수이다. 본 논문에서는 이러한 파라미터를 정규화시켜 해석하므로 각 파라미터가 채널 Through-put에 미치는 영향을 검토하였으며 특히, 토큰 링방식과 토큰 버스방식에 대한 해석으로 각 파라미터와의 관계를 고찰하여 CSMA/CD방식과의 비교 검토를 하였다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.143-146
• /
• 2008

Dynamic range of LCD panel can be dramatically improved by adaptive dimming technique. Adaptive control of LED backlight by input signal can reduce the light leakage of LCD panel and achieve high contrast ratio. An algorithm is proposed to distinguish the input signal and get proper luminance level. For lower cost of LCD panel, white light LED is used to accomplish 2D dimming and get better image performance of LCD.