• Title/Summary/Keyword: Disturbance detection

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A Study on Automatic Seam Tracking of Arc Welding Using an Laser Displacement Sensor (레이져 변위센서를 이용한 용접선 자동추적에 관한 연구(2))

  • 양상민;조택동;전진환
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.729-733
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    • 1997
  • Due to the variety of disturbance, it is not ease to accomplish the in-process detection of weld line with non-contact sensor. To get around this difficulties problem develop an automatic seam tracking weld system, the reliable signal processing algorithm has been recommanded. In this research, laser displacement sensor is applied as a seam finder in the automatic tracking system. The sensor is controlled by a dc servo motor which is mounted at X-Y moving table. X-Y moving table manipulated by an ac servo motor controls the position and velocity of the welding torch. First, X-Y table moves to Y-axis to search the welding joint feature before starting the welding, and welding joint is from the scanning data and weighting factor for each other. Second, weld line is determined using proposed signal processing algorithm during welding process. Form the experimental results, we could see the possibility that laser displacement sensor with procesed algorithm can be used as a seam finder in welding process under the severe noise (spatter,arc light etc.) condition

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Analysis and application of the dynamically tuned gyroscope (Angular velocity sensor of EOTS) (동조자이로스코프의 해석 및 응용 (전자광학추적기의 회전각속도 센서))

  • Im, Sung-Woon
    • Journal of Sensor Science and Technology
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    • v.5 no.4
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    • pp.47-56
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    • 1996
  • The basic principle and characteristics of a DTG(dynamically tuned gyroscope) are presented in this paper, which is used for the detection of disturbance and for the stabilization of gimbal. An accurate model of the rate mode DTG is proposed. This model has a resonance characteristics which is more similar to the characteristics of practical systems than the conventional 2nd order system model. Therefore, this model is applicable to the general rate mode gyroscope. Some problems at using DTG for a real electro optical tracking system are discussed and a solution is described.

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Apoptosis in Cancer - An Update

  • Sankari, S. Leena;Masthan, K.M.K.;Babu, N. Aravindha;Bhattacharjee, Tathagata;Elumalai, M.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.10
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    • pp.4873-4878
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    • 2012
  • Apoptosis is programmed cell death which is essential for development and survival of living organisms. It is a sequentially regulated suicidal programme where cells activate certain enzymes which dissolute their own nuclear component and various protein component of nucleus and cytoplasm. Disturbance of this regulatory pathway may lead to various diseases like autoimmune diseases, neurodegenerative diseases and cancers. The potential mechanisms of apoptosis and its role in cancer are discussed. The ability of apoptosis to modulate the life or death of a cell is also recognized for its immense therapeutic potential. Understanding the mechanisms from this review will give us better insight to the pathogenesis of various diseases including cancer and will open new horizons to therapeutic approaches.

Simple Technique for Measurement of Complex Permittivity and Detection of Small Permittivity Change Using Partially Open Cavity

  • Park, Sangbok;Chung, Young-Seek;Cheon, Changyul
    • Journal of Electrical Engineering and Technology
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    • v.9 no.1
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    • pp.268-272
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    • 2014
  • This letter presents a measurement methodology of the complex permittivity of liquid using a partially open cavity in narrow band. The partially open cavity (POC) can measure dielectric small changes caused by the temperature variation of the liquid inside the cavity as well. Using the resonance frequency and unloaded quality factor of the proposed POC, the complex permittivity is evaluated. The apertures on the walls of the cavity are designed to circulate the liquid inside to outside of the POC and located at the corner area of the cavity to minimize the disturbance of field distribution at the dominant mode. The results measured by the proposed POC were compared with those by the conventional open-ended probe and Cole-Cole equation. The POC showed better performance in measuring small dielectric constant changes than the open-ended probe.

A Study of Voltage Sag Detection Using Wavelet Transform (웨이블릿 변환을 이용한 순간전압강하 검출 연구)

  • Lee, Kyo-Sung;Lee, Yong-Jae;Kim, Do-Hun;Kim, Yang-Mo
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.3-5
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    • 2002
  • The fourier transform yields good information on the frequency content of the transient, but the time at which a particular disturbance in the signal occurred is lost. Unlike the fourier transform, the wavelet transform provides a time information in addition to the frequency information. So the wavelet transform is more efficient in detecting power quality disturbances. In this paper, we use the wavelet transform for detecting the voltage sag.

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Precision Position Control for PCB Screen Printer Using Image Processing (화상처리를 이용한 PCB 스크린 인쇄기의 정밀위치제어)

  • 이근유;부이트롱휴;김동규;박순실;김상봉
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.295-295
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    • 2000
  • In this paper, the measurement algorithm of PCB alignment error is developed using image processing. The X-Y-$\theta$ table correcting PCB alignment error is driven by drive module based on microprocessor according to calculation results obtained through image processing procedure. In order to recognize the X-Y-$\theta$ position errors, two fiducial points are marked on PCB and two cameras of ultraviolet rays types are used for detection of the points to capture exactly fiducial points under disturbance of illumination change. Through application for a practical screen printer, the precision control using the developed position control system can be realized about 2.5${\mu}{\textrm}{m}$ in table moving range and 8${\mu}{\textrm}{m}$ in camera processing precision.

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Design and Implementation of the Intrusion Detection Data Web-based Management System on Heterogeneous Environments (이기종간 침입탐지 정보에 대한 웹기반 관리 시스템 설계)

  • Kim, Eun-Soo;Kim, Seok-Hun;Song, Jung-Gil
    • Convergence Security Journal
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    • v.5 no.2
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    • pp.65-74
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    • 2005
  • The hacking accident is increasing repidly according to development of latest computer network and the method becomes various. But, to correspond to hacking, it is lot of difficulties to cope gear and security element between product because most radiant mercuries apply technology between individual digenomic species and It is real condition that great setup, equipment, manpower disturbance are enlarged to apply this. Designed and embody Site-Based executive system that can integrate security element about IDS information between digenomic species to solve these problem and correspond efficiently from hacking.

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Detection of Anormalies on the Power Line using the Instantaneous Frequencies (순간주파수를 이용한 전력선 신호의 이상현상검출)

  • Iem, Byeong-Gwan
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.12
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    • pp.544-548
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    • 2006
  • The instantaneous frequency gives a frequency value at a time instance. Thus, it is natural to use the instantaneous frequency for detecting disturbances of voltage signal in power line. Various instantaneous frequency estimators are introduced. By applying to different types of disturbed signals, we show the estimators' ability to classify flickers. Also, the computational costs are compared between different instantaneous frequency estimators. The Prony's method (PRONY) and the modified covariance method (MCOV) need relatively smaller amount of calculation than the Teaser-Kaiser energy operator based estimator (DESA II). For an AM-FM modulated signal, the tracking performance of different instantaneous frequency estimators is also compared. Through simulation, it is shown that MCOV produces less variant frequency estimation values than DESA II and PRONY method.

Fault Isolation for a Diesel Engine Actuator (디젤엔진 위치서보시스템을 위한 고장 식별)

  • Park, Tae-Geon;Hur, Hak-Bom;Lee, Kee-Sang
    • Proceedings of the KIEE Conference
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    • 1998.07b
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    • pp.417-419
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    • 1998
  • In a large diesel engine actuator position servo system, it is impossible to isolate an actuator fault from a load torque with conventional fault detection isolation (FDI) schemes because they are propagated through a channel. This paper deals with a parity equation based residual generation to isolate them in the system. The actuator fault is modelled by a multiplicative type fault that can be characterized as discrepancies between the nominal and actual plant parameters, whereas the load torque is modelled by an additive disturbance. The transformation implemented in the residual generator should be determined on-line to achieve the isolation. Simulation studies show the practical applicability of the FDI scheme.

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A Power Disturbance Classification System using Wavelet-Based Neural Network (웨이블릿 기반의 뉴럴네트웍을 이용한 전원의 왜란분류 시스템)

  • Kim, Hong-Kyun;Lee, Jin-Mok;Choi, Jae-Ho
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.487-489
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    • 2005
  • This paper presents a wavelet-based neural network technology for the detection and classification of the short durations type of power quality disturbances. Transients happen during very short durations to the nano- and microsecond. Thus, a method for detecting and classifying transient signals at the same time and In an automatic combines the properties of the wavelet transform and the advantages of neural networks. Especially, the additional feature extraction to improve the recognition rate is considered. The configuration of the hardware of TMS320C6711 DSP based with 16 channel 20Mhz sampling rate A/D(Analog to Digital) converter and some case studies are described.

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