• Title/Summary/Keyword: Sensor Technique

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An internal partial discharge measurement method excepted an external corona noise (외부 코로나 노이즈를 제거한 내부 부분방전 측정기법)

  • 권동진;진상범;곽희로
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.1
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    • pp.44-50
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    • 2001
  • The largest problem in applying the elecbical partial discharge measurement method the transformer that has been operated until now is the removal of external corona noise In this thesis, a methcd was studied. to rneasme only fue partial discharge sIgnal due to the defoct in transfonrer except the external corona noise. To find out the types of partial discharge and corona noise within a transfomr, a partial discharge was made in use of a needle-plane electrodes within a model transfonner and, at the same time, an external corona noise was generated in use of a rod-sphere electrcdes in the air around the transformer. Both of a partial clischarge signal caused from an intemat defect within a transformer and an external noise were found at the rogowski coil which was located at transformer earth wire. When the external corona noise, which was separately measured in use of an antenna sensor out of transfonner, was removed from the signal measured on rogowski coil, the signal caused by partial discharge within a transformer would effectively be acquired.quired.

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A Design of Du-CNN based on the Hybrid Machine Characters to Classify Target and Clutter in The IR Image (적외선 영상에서의 표적과 클러터 구분을 위한 Hybrid Machine Character 기반의 Du-CNN 설계)

  • Lee, Juyoung;Lim, Jaewan;Baek, Haeun;Kim, Chunho;Park, Jungsoo;Koh, Eunjin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.6
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    • pp.758-766
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    • 2017
  • In this paper, we propose a robust duality of CNN(Du-CNN) method which can classify the target and clutter in coastal environment for IR Imaging Sensor. In coastal environment, there are various clutter that have many similarities with real target due to diverse change of air temperature, water temperature, weather and season. Also, real target have various feature due to the same reason. Thus, the proposed Du-CNN method adopts human's multiple personality utilization and CNN technique to learn and classify target and clutter. This method has an advantage of the real time operation. Experimental results on sampled dataset of real infrared target and clutter demonstrate that the proposed method have better success rate to classify the target and clutter than general CNN method.

An Accurate Moving Distance Measurement Using the Rear-View Images in Parking Assistant Systems (후방영상 기반 주차 보조 시스템에서 정밀 이동거리 추출 기법)

  • Kim, Ho-Young;Lee, Seong-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.12
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    • pp.1271-1280
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    • 2012
  • In the recent parking assistant systems, finding out the distance to the object behind a car is often performed by the range sensors such as ultrasonic sensors, radars. However, the installation of additional sensors on the used vehicle could be difficult and require extra cost. On the other hand, the motion stereo technique that extracts distance information using only an image sensor was also proposed. However, In the stereo rectification step, the motion stereo requires good features and exacts matching result. In this paper, we propose a fast algorithm that extracts the accurate distance information for the parallel parking situation using the consecutive images that is acquired by a rear-view camera. The proposed algorithm uses the quadrangle transform of the image, the horizontal line integral projection, and the blocking-based correlation measurement. In the experiment with the magna parallel test sequence, the result shows that the line-accurate distance measurement with the image sequence from the rear-view camera is possible.

Endpoint Detection Using Hybrid Algorithm of PLS and SVM (PLS와 SVM복합 알고리즘을 이용한 식각 종료점 검출)

  • Lee, Yun-Keun;Han, Yi-Seul;Hong, Sang-Jeen;Han, Seung-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.9
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    • pp.701-709
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    • 2011
  • In semiconductor wafer fabrication, etching is one of the most critical processes, by which a material layer is selectively removed. Because of difficulty to correct a mistake caused by over etching, it is critical that etch should be performed correctly. This paper proposes a new approach for etch endpoint detection of small open area wafers. The traditional endpoint detection technique uses a few manually selected wavelengths, which are adequate for large open areas. As the integrated circuit devices continue to shrink in geometry and increase in device density, detecting the endpoint for small open areas presents a serious challenge to process engineers. In this work, a high-resolution optical emission spectroscopy (OES) sensor is used to provide the necessary sensitivity for detecting subtle endpoint signal. Partial Least Squares (PLS) method is used to analyze the OES data which reduces dimension of the data and increases gap between classes. Support Vector Machine (SVM) is employed to detect endpoint using the data after PLS. SVM classifies normal etching state and after endpoint state. Two data sets from OES are used in training PLS and SVM. The other data sets are used to test the performance of the model. The results show that the trained PLS and SVM hybrid algorithm model detects endpoint accurately.

Information Fusion of Photogrammetric Imagery and Lidar for Reliable Building Extraction (광학 영상과 Lidar의 정보 융합에 의한 신뢰성 있는 구조물 검출)

  • Lee, Dong-Hyuk;Lee, Kyoung-Mu;Lee, Sang-Uk
    • Journal of Broadcast Engineering
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    • v.13 no.2
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    • pp.236-244
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    • 2008
  • We propose a new building detection and description algorithm for Lidar data and photogrammetric imagery using color segmentation, line segments matching, perceptual grouping. Our algorithm consists of two steps. In the first step, from the initial building regions extracted from Lidar data and the color segmentation results from the photogrammetric imagery, we extract coarse building boundaries based on the Lidar results with split and merge technique from aerial imagery. In the secondstep, we extract precise building boundaries based on coarse building boundaries and edges from aerial imagery using line segments matching and perceptual grouping. The contribution of this algorithm is that color information in photogrammetric imagery is used to complement collapsed building boundaries obtained by Lidar. Moreover, linearity of the edges and construction of closed roof form are used to reflect the characteristic of man-made object. Experimental results on multisensor data demonstrate that the proposed algorithm produces more accurate and reliable results than Lidar sensor.

A Comparative Study on Healthcare Autonomous Vehicle Technologies between South Korea and the US Based on Social N etwork Analysis (헬스케어 관련 자율주행 자동차 기술 한미 비교 연구 : 사회연결망 분석을 중심으로)

  • Kim, Ho-Kyung
    • Journal of Korea Technology Innovation Society
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    • v.20 no.4
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    • pp.1036-1056
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    • 2017
  • The rapid increase of ageing population and chronic disease patients cause high medical expenses, and it led an increased attention to digital healthcare. Smart car technologies for healthcare have been developing to recognize drivers' status and predict diverse driving environments. The present study aimed to understand the research trends of autonomous vehicle technologies of Korea and the United States through time series analysis, network analysis, visualization, and comparison between the two countries. The results suggest that cooperative study needs to be done in common research areas such as driver's safety and algorithms. It is also needed to conduct studies and benchmark about liking technique related to part-to-part and vehicle-to-vehicle as America's competitive advantaged area. In the US, diverse approaches of autonomous vehicle technologies have used to consider the characteristics of various age groups and passengers' health status through sensor, while in Korea, only one aspect, older drivers, is mentioned. Implications for the development direction of autonomous vehicle technologies with competitiveness in considering public health, ethics, and driver's safety and convenience are discussed in detail.

Active Facial Tracking for Fatigue Detection (피로 검출을 위한 능동적 얼굴 추적)

  • Kim, Tae-Woo;Kang, Yong-Seok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.3
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    • pp.53-60
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    • 2009
  • The vision-based driver fatigue detection is one of the most prospective commercial applications of facial expression recognition technology. The facial feature tracking is the primary technique issue in it. Current facial tracking technology faces three challenges: (1) detection failure of some or all of features due to a variety of lighting conditions and head motions; (2) multiple and non-rigid object tracking; and (3) features occlusion when the head is in oblique angles. In this paper, we propose a new active approach. First, the active IR sensor is used to robustly detect pupils under variable lighting conditions. The detected pupils are then used to predict the head motion. Furthermore, face movement is assumed to be locally smooth so that a facial feature can be tracked with a Kalman filter. The simultaneous use of the pupil constraint and the Kalman filtering greatly increases the prediction accuracy for each feature position. Feature detection is accomplished in the Gabor space with respect to the vicinity of predicted location. Local graphs consisting of identified features are extracted and used to capture the spatial relationship among detected features. Finally, a graph-based reliability propagation is proposed to tackle the occlusion problem and verify the tracking results. The experimental results show validity of our active approach to real-life facial tracking under variable lighting conditions, head orientations, and facial expressions.

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Active Facial Tracking for Fatigue Detection (피로 검출을 위한 능동적 얼굴 추적)

  • 박호식;정연숙;손동주;나상동;배철수
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2004.05b
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    • pp.603-607
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    • 2004
  • The vision-based driver fatigue detection is one of the most prospective commercial applications of facial expression recognition technology. The facial feature tracking is the primary technique issue in it. Current facial tracking technology faces three challenges: (1) detection failure of some or all of features due to a variety of lighting conditions and head motions; (2) multiple and non-rigid object tracking and (3) features occlusion when the head is in oblique angles. In this paper, we propose a new active approach. First, the active IR sensor is used to robustly detect pupils under variable lighting conditions. The detected pupils are then used to predict the head motion. Furthermore, face movement is assumed to be locally smooth so that a facial feature can be tracked with a Kalman filter. The simultaneous use of the pupil constraint and the Kalman filtering greatly increases the prediction accuracy for each feature position. Feature detection is accomplished in the Gabor space with respect to the vicinity of predicted location. Local graphs consisting of identified features are extracted and used to capture the spatial relationship among detected features. Finally, a graph-based reliability propagation is proposed to tackle the occlusion problem and verify the tracking results. The experimental results show validity of our active approach to real-life facial tracking under variable lighting conditions, head orientations, and facial expressions.

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The Fuzzy Steering Control Using a Slope Direction Estimation Method for Small Unmanned Ground Vehicle (경사방향 추정 기법을 이용한 소형로봇의 퍼지 조향 제어)

  • Lee, Sang Hoon;Huh, Jin Wook;Kang, Sincheon;Lee, Myung Chun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.6
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    • pp.721-728
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    • 2012
  • The tracked SUGVs(Small Unmanned Ground Vehicles) are frequently operated in the narrow slope such as stairs and trails. But due to the nature of the tracked vehicle which is steered using friction between the track and the ground and the limited field of view of driving cameras mounted on the lower position, it is not easy for SUGVs to trace narrow slopes. To properly trace inclined narrows, it is very important for SUGVs to keep it's heading direction to the slope. As a matter of factor, no roll value control of a SUGV can makes it's heading being located in the direction of the slope in general terrains. But, the problem is that we cannot directly control roll motion for SUGV. Instead we can control yaw motion. In this paper, a new slope driving method that enables the vehicle trace the narrow slopes with IMU sensor usually mounted in the SUGV is suggested which including an estimation technique of the desired yaw angle corresponding to zero roll angle. In addition, a fuzzy steering controller robust to changes in driving speed and the stair geometry is designed to simulate narrow slope driving with the suggested method. It is shown that the suggested method is quite effective through the simulation.

Development and Evaluation of an Self-Operated Face Capturing System (자가 안면영상 촬영장치 개발 및 검증)

  • Jeon, Young-Ju;Do, Jun-Hyeong;Kim, Jang-Wong;Kim, Sang-Gil;Lee, Hae-Jung;Lee, Yu-Jung;Kim, Keun-Ho;Kim, Jong-Yeol
    • Korean Journal of Oriental Medicine
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    • v.17 no.2
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    • pp.115-120
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    • 2011
  • Objectives : The purpose of this study is to develop an apparatus which can take a facial image by self-operated capturing technique. The user can obtain one's facial image immediately after adjusting facial tilt and focusing distance. The system has been designed for classifying Sasang typology based on facial image. Methods : The system is composed of a Webcam, one-way glass mirror and mini LCD. The Webcam takes a facial image which is displayed on the mini LCD. Then the user can see and adjust to the right position in the real time through the image mirror-reflected from the mini LCD. The optical sensor is used to estimate the proper focusing distance. To verify the performance of the system, 11 characteristic points on the facial image are used and compared with high performance DSLR camera(D700) by applying the coefficient of variance and Bland-Altman Plot. Results : The developed system and D700 show enough agreement with the small coefficient of variance to analyse constitutional types with a facial im mage. However, the result of Bland-Altman plot shows that the width parameters have distortions owing to short focusing distance. Conclusions : The system is expected to be utilized on u-healthcare services for home environment after improving the distortion in the width parameters.