• Title/Summary/Keyword: Detection characteristics

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Design and Characteristics of AE Sensor for Detection of Metallic particle in GIS (GIS 내의 금속이물 탐지용 AE 센서의 설계와 특성)

  • 홍재일;정영호;류주현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.6
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    • pp.502-508
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    • 2000
  • In order to detect the partial discharge with the metallic particle in GIS the AE(Acoustic Emission) sensor was designed and simulated by ANSYS 5.5 and manufactured as the coupled vibration mode. The measured resonant frequency and the maximum sensitivity frequency of three coupled AE sensors were as follows ; 147.88 kHz in 8.1mm $\Phi$$\times$8.1mm 128.82 kHz and 58.8 kHz in 9.5 mm$\Phi$$\times$9.5mm, 85.22 kHz and 32.6 kHz in 14.3 mm$\Phi$$\times$14.3 mm, resonant frequency of the AE sensor. The AE sensor of 9.5 mm$\Phi$$\times$9.5mm responded higher than the other coupled vibration mode AE sensor at the partial discharge detection in GIS.

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Fault Detection and Isolation for Inertial Sensor Using Single Antenna GPS Receiver (단일 안테나 GPS 수신기를 이용한 관성센서의 고장검출 및 분리)

  • 김영진;김유단
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.11
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    • pp.1037-1043
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    • 2004
  • In this paper, a new fault detection and isolation algorithm fur inertial sensor system is proposed. To identify the inertial sensor fault, single antenna GPS receiver is used as an effective redundancy source. To use GPS receiver as redundancy for the inertial sensors, the algorithm to estimate the attitude and acceleration using single antenna GPS receiver is adopted. By using Doppler shift of carrier phase signal and kinetic characteristics of aircraft, attitude information of aircraft can be obtained at the coordinated flight condition. Based on this idea, fault diagnosis algorithm for inertial sensors using single antenna GPS based attitude is proposed. For more effective FDI, decision variables considering the aircraft maneuver are proposed. The effectiveness of the proposed algorithm is verified through the numerical simulations.

Developed of non-differential pulse detection (비미분형 맥동검출변환기 개발)

  • Kim, H.K.;Han, S.H.;Lee, Y.D.;Park, Y.B.;Huh, W.
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.573-576
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    • 1998
  • In this paper, we devised pulse detection transducer that has non-differential characteristics for pulse detection on chongu arterial. The transducer consist of load cell and driving electronic circuits. Load cell consist of cantilever and two metal film strain gauge. The pressure signal from chongu artery is delivered to load cell using artery rider that attached to cantilever. Therefore the pressure pulse signal can obtain by the developed transducer. As the results of experiment, the developed transducer has a good linearity at pressure to voltage conversion and acan detect non-differential pulse signal from chongu artery.

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Efficient Lane Detection Using Histogram Based Segmentation (히스토그램을 이용한 효율적인 차선검출)

  • 남기환;배철수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.5
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    • pp.1062-1067
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    • 2003
  • A vision system for Intelligent vehicles here. The system exploits the characteristics of the gray level histogram of the road to detect lane markers. Each lane maker is then analyzed using a decision tree, and finally the relations between lane markers are analyzed to create structures defining the lane boundaries. The resulting system also generates images that can be used ae preprocessing stages in lane detection, lane tracking or obstacle detection algorithm. The system runs in realtime ay rates of about 30Hz.

Signal Analysis of Motor Current for End Point Detection in the Chemical Mechanical Polishing of Shallow Trench Isolation with Reverse Moat Structure

  • Park, Chang-Jun;Kim, Sang-Yong;Seo, Yong-Jin
    • KIEE International Transactions on Electrophysics and Applications
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    • v.2C no.5
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    • pp.262-267
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    • 2002
  • In this paper, we first studied the factors affecting the motor current (MC) signal, which was strongly affected by the systematic hardware noises depending on polishing such as pad conditioning and arm oscillation of platen and recipe, head motor. Next, we studied the end point detection (EPD) for the chemical mechanical polishing (CMP) process of shallow trench isolation (STI) with reverse moat structure. The MC signal showed a high amplitude peak in the fore part caused by the reverse meal. pattern. We also found that the EP could not be detected properly and reproducibly due to the pad conditioning effect, especially when conventional low selectivity slurry was used. Even when there was no pad conditioning effect, the EPD method could not be applied, since the measured end points were always the same due to the characteristics of the reverse moat structure with an open nitride layer.

An algorithm for Video Object Detection using Multiresolution Motion Estimation (다해상도 움직임 예측을 이용한 동영상 물체탐지 알고리즘)

  • 조철훈;박장한;이한우;남궁재찬
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.1
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    • pp.87-95
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    • 2003
  • This paper proposes an object detection algorithm using the Multiresolution Motion Estimation(MRME) in wavelet d야main. A existing motion estimation method has characteristics of motion estimation but it requires having computation. Motion estimation in higher resolution used the motion vector of the lower resolution with the MRME that has parent-child relationship on wavelet coefficients. This method reduces the search area of motion estimation in higher resolution and computational complexity. The computational complexity of the proposed method is about 40% of the existing method using 3-level Set Partitioning in Hierarchical Trees(SPIHT) wavelet transform. The experimental results with the proposed method showed about 11% decrease of Mean Absolute Difference(MAD) and gains able to precise tracking of object.

The Analysis of the Pressure Fluctuation in the Exhaust System According to the Assistant Device Configuration (보조기구의 형상 변경에 따른 배기계에서의 압력 변동 분석)

  • Chung, Sung-Won;Sim, Kook-Sang
    • Journal of the Korean Society of Industry Convergence
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    • v.6 no.4
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    • pp.325-331
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    • 2003
  • This paper described the characteristics of the exhaust pressure and proposed the assistant device for detection of misfired cylinder. Misfire, one of abnormal combustion, affects a bad influence of the 3-way catalyst and emits unburned hydrocarbon. Therefore, to prevent these unusual phenomena and eliminate the factor of the environmental pollution, early detection and correction of the misfired cylinder play a very important role. The configuration of assistant device was changed by length and diameter of pipe and analyzed with the install position on the exhaust system. Experimental results showed that the configuration of assistant device is not affected more than length and diameter of pipe and the assistant device is be effective in the detection of misfired cylinder on the gasoline engine.

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Feasibility Study of Sludge Detection inside Pipes Using Torsional Guided Waves (비틀림 유도파를 이용한 배관 슬러지 검출 방법의 현장 적용성 평가)

  • Park, Kyung-Jo
    • Journal of Power System Engineering
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    • v.18 no.5
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    • pp.100-105
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    • 2014
  • It has been previously reported that in principle sludge and blockages can be detected and even characterized by using guided ultrasonic torsional waves, based on an idealized model in which the sludge layer was simplified in terms of geometry and material properties. The work revealed that the presence of a layer inside a pipe scatters the guided wave propagating in the pipe and both the reflection and transmission of the guided wave can be used to effectively detect and characterize the layer. This paper proceeds the work by taking into account more realistic sludge characteristics, including irregular circumferential profiles of the sludge layer and imperfect bonding state between the sludge and the pipe. The influence of these issues is investigated to identify the critical factors that influence the detection and characterization capability of the two measurements.

Fabrication of a Single Molecule Detection System and Its Application: Connection between Ensemble and Single Molecule Measurements

  • Park, Mira;Lee, Heung Soon;Kim, DongHo;Song, Nam Woong
    • Journal of Photoscience
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    • v.11 no.32
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    • pp.47-53
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    • 2004
  • A laser scanning fluorescence microscope system has been fabricated for single molecule detection (SMD). Problems associated with the system set-up have been discussed along with proper suggestions. Based on the SMD results obtained by using the apparatus, a statistical method has been suggested to determine the minimum number of required molecules to form a group of uniform average in a selected error range.

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Multiple Object Tracking Using SIFT and Multi-Lateral Histogram (SIFT와 다중측면히스토그램을 이용한 다중물체추적)

  • Jun, Jung-Soo;Moon, Yong-Ho;Ha, Seok-Wun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.9 no.1
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    • pp.53-59
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    • 2014
  • In multiple object tracking, accurate detection for each of objects that appear sequentially and effective tracking in complicated cases that they are overlapped with each other are very important. In this paper, we propose a multiple object tracking system that has a concrete detection and tracking characteristics by using multi-lateral histogram and SIFT feature extraction algorithm. Especially, by limiting the matching area to object's inside and by utilizing the location informations in the keypoint matching process of SIFT algorithm, we advanced the tracking performance for multiple objects. Based on the experimental results, we found that the proposed tracking system has a robust tracking operation in the complicated environments that multiple objects are frequently overlapped in various of directions.