• 제목/요약/키워드: Start/End point

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웹TV에서 방송 프로그램 시작 및 종료를 검출하는 방법 : 흑 레벨 검출 중심으로 (Method for Detecting Start/End Time of TV Program on Web TV : By Detecting Black Level on Screen)

  • 김용필;김광호
    • 한국콘텐츠학회논문지
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    • 제15권1호
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    • pp.1-8
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    • 2015
  • 본 논문은 웹TV에서 방송프로그램의 시작과 종료의 인지에 대한 연구이다. 현재 웹TV 서비스를 위하여 VOD 파일을 생성하고, 실시간방송의 광고를 웹TV용 광고로 교체하기 위해 수동적인 방법을 이용하고 있다. 이를 자동화하기 위해서는 방송프로그램의 시작과 종료 지점을 인지해야 한다. 본 논문에서는 실시간으로 프로그램과 프로그램 사이에 발생하는 흑 레벨(Black Level)을 검출하여 방송 프로그램 시작과 종료 지점으로 인지하여, 방송프로그램의 시작과 종료 신호를 발생하여 자동으로 VOD 파일을 생성하고, 웹TV용 광고로 교체할 수 있는 기법을 제안한다.

최소자승법을 이용한 수직다관절 Manipulator의 원호보간에 관한 효과적인 방법 (An Efficient Approach to Circular Curve Fitting of Articulated Manipulators Using Least Squares)

  • 김대영;최은재;정원지;서영교;홍형표
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.570-575
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    • 2002
  • This paper presents a new circular curve fitting approach of articulated manipulators, based on pseudoinverses. The paper aims at gaining the interpolation of circle from n data points, under the condition that the fitted circle should pass both a start point and an end point. In this paper, two algorithms of circular interpolation are presented. Prior to circular interpolation, are a spherical fitting should be performed, using least squares. In the first algorithm, the relationship between point data and normal vector on the sphere is used. In the second algorithm. the equation of plane which can be obtained from 3 points, i.e., a start point, an end point, and center of a sphere. The proposed algorithms are show to be efficient by using MATLAB-based simulation.

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P Wave Detection based on QRST Cancellation Zero-One Substitution

  • Cho, Ik-Sung
    • Journal of information and communication convergence engineering
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    • 제19권2호
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    • pp.93-101
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    • 2021
  • Cardiac arrhythmias are common heart diseases and generally cause sudden cardiac death. Electrocardiogram (ECG) is an effective tool that can reveal the electrical activity of the heart and diagnose cardiac arrhythmias. We propose detection of P waves based on QRST cancellation zero-one substitution. After preprocessing, the QRST segment is determined by detecting the Q wave start point and T wave end point separately. The Q wave start point is detected by digital analyses of the QRS complex width, and the T wave end point is detected by computation of an indicator related to the area covered by the T wave curve. Then, we determine whether the sampled value of the signal is in the interval of the QRST segment and substitute zero or one for the value to cancel the QRST segment. Finally, the maximum amplitude is selected as the peak of the P wave in each RR interval of the residual signal. The average detection rate for the QT database was 97.67%.

다중 심층신경망을 이용한 심전도 파라미터의 획득 및 분류 (Acquisition and Classification of ECG Parameters with Multiple Deep Neural Networks)

  • 김지운;박성민;최성욱
    • 대한의용생체공학회:의공학회지
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    • 제43권6호
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    • pp.424-433
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    • 2022
  • As the proportion of non-contact telemedicine increases and the number of electrocardiogram (ECG) data measured using portable ECG monitors increases, the demand for automatic algorithms that can precisely analyze vast amounts of ECG is increasing. Since the P, QRS, and T waves of the ECG have different shapes depending on the location of electrodes or individual characteristics and often have similar frequency components or amplitudes, it is difficult to distinguish P, QRS and T waves and measure each parameter. In order to measure the widths, intervals and areas of P, QRS, and T waves, a new algorithm that recognizes the start and end points of each wave and automatically measures the time differences and amplitudes between each point is required. In this study, the start and end points of the P, QRS, and T waves were measured using six Deep Neural Networks (DNN) that recognize the start and end points of each wave. Then, by synthesizing the results of all DNNs, 12 parameters for ECG characteristics for each heartbeat were obtained. In the ECG waveform of 10 subjects provided by Physionet, 12 parameters were measured for each of 660 heartbeats, and the 12 parameters measured for each heartbeat well represented the characteristics of the ECG, so it was possible to distinguish them from other subjects' parameters. When the ECG data of 10 subjects were combined into one file and analyzed with the suggested algorithm, 10 types of ECG waveform were observed, and two types of ECG waveform were simultaneously observed in 5 subjects, however, it was not observed that one person had more than two types.

플라즈마 식각공정에서의 EPD(End Point Detection) 제어기에 관한 연구 (A study on EPD(End Point Detection) controller on plasma teaching process)

  • 최순혁;차상엽;이종민;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.415-418
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    • 1996
  • Etching Process, one of the most important process in semiconductor fabrication, has input control part of which components are pressure, gas flow, RF power and etc., and plasma gas which is complex and not exactly understood is used to etch wafer in etching chamber. So this process has not real-time feedback controller based on input-output relation, then it uses EPD(End Point Detection) signal to determine when to start or when to stop etching. Various type EPD controller control etching process using EPD signal obtained from optical intensity of etching chamber. In development EPD controller we concentrate on compensation of this signal intensity and setting the relative signal magnitude at first of etching. We compensate signal intensity using neural network learning method and set the relative signal magnitude using fuzzy inference method. Potential of this method which improves EPD system capability is proved by experiences.

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조기심실수축 분류를 위한 위상 변이 추적 기반의 QRS 특징점 검출 (Detection of QRS Feature Based on Phase Transition Tracking for Premature Ventricular Contraction Classification)

  • 조익성;윤정오;권혁숭
    • 한국정보통신학회논문지
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    • 제20권2호
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    • pp.427-436
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    • 2016
  • 일반적으로 QRS간격은 시작점을 기준으로 끝점까지의 간격을 말하지만 그 기준이 모호하고 Q와 S의 검출이 정확하지 않아 부정맥 분류 성능을 저하시키는 경우가 발생한다. 본 연구에서는 심전도신호 중 가장 큰 피크인 R파를 정확히 검출한 후 이를 기준으로 위상 변이 추적 기법을 적용하여 Q와 S의 시작점과 끝점을 추출하는 방법을 제안한다. 먼저 전처리 과정을 통해 잡음이 제거된 정확한 R파를 검출한다. 이후 심전도신호의 미분값을 통해 QRS패턴을 분류하고, R파를 기준으로 위상이 변화되는 방향과 횟수를 추적함으로써 Q, S의 시작점과 끝점을 추출하는 방법이다. 제안한 방법의 우수성을 입증하기 위해 MIT-BIH 부정맥 데이터베이스 48개의 레코드를 대상으로 R파 검출율은 99.60%의 성능을 나타내었고, 위상 변이 추적 기법의 경우 조기심실수축(PVC)이 30개 이상 포함된 MIT-BIH 10개의 레코드를 대상으로 조기심실수축 분류율을 각각 비교 분석한 결과 94.12%로 우수하게 나타났다.

선독 알고리즘에 의한 고속 가공 소프트웨어 구현 (The Implement of a high Speed Machining Software by Look-ahead Algorithm)

  • 이철수
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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    • pp.252-257
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    • 2000
  • This paper describes a look-ahead algorithm of PCNC(personal computer numerical control). The algorithm is based on acceleration/deceleration before interpolation never including a command error and determines a velocity value in end point of each block(or start point of each block). The algorithm is represented as following; 1) calculating two maximum arrival velocity(v1, v2) by a acceleration value, a command velocity and distance in a previous block and a next block, 2) getting a tangent velocity(v3) of the adjacent blocks, 3) choosing a minimum value among these three velocities, and 4) setting the value to a velocity of a start point of the next block(or a end point of the previous block). The proposed look-ahead algorithm was implemented and tested by using a commercial RTOS(real time operation system) on the MS-Windows NT 4.0 in a PC platform. For interfacing to a machine, a counter board, a DAC board and a DIO board were used. The result of the algorithm increased a machining precision and a machining speed in many short blocks.

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고속가공을 위한 2단계 모션 제어 루프와 선독 알고리즘의 구현 (The Implement of 2-Step Motion Control Loop and Look Ahead Algorithm for a High Speed Machining)

  • 이철수;이제필
    • 한국생산제조학회지
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    • 제9권6호
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    • pp.71-81
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    • 2000
  • This paper describers a look ahead algorithm of PC-NC(personal computer numerical control). The algorithm is based on acceleration/deceleration before interpolation which doesn\`t include a command error and determines a feedrate value at the end point of each block(or start point of each block). The algorithm is represented as following; 1) calculating two maximum arrival feedrates(F$_1$,F$_2$) by an acceleration value, a command feedrate, and the distance of a NC block, 2) getting a tangent feedrate (F$_3$) of the adjacent blocks, 3) choosing a minimum value among these three feedrates, and 4) setting the value to a feedrate of a start point of the next block(or a end point of the previous block). The proposed look ahead algorithm was implemented and tested by using a commercial TROS(real time operation system) on the MS-Windows NT 4.0 in a PC platform. For interfacing to a machine, a counter board, a DAC board and a DIO board were used. The result of the algorithm increased a machining precision and a machining speed in many short blocks.

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향상된 수렴 속도와 근단 화자 신호 검출능력을 갖는 적응 반향 제거기 (On Improving Convergence Speed and NET Detection Performance for Adaptive Echo Canceller)

  • 김남선
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1992년도 학술논문발표회 논문집 제11권 1호
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    • pp.23-28
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    • 1992
  • The purpose of this paper is to develop a new adaptive echo canceller improving convergence speed and near-end-talker detection performance of the conventional echo canceller. In a conventional adaptive echo canceller, an adaptive digital filter with TDL(Tapped-Delay Line) structure modelling the echo path uses the LMS(Least Mean Square) algorithm to cote the coefficients, and NET detector using energy comparison method prevents the adaptive digital filter to update the coefficients during the periods of the NET signal presence. The convergence speed of the LMS algorithm depends on the eigenvalue spread ratio of the reference signal and NET detector using the energy comparison method yields poor detection performance if the magnitude of the NET signal is small. This paper presents a new adaptive echo canceller which uses the pre-whitening filter to improve the convergence speed of the LMS algorithm. The pre-whitening filter is realized by using a low-order lattice predictor. Also, a new NET signal detection algorithm is presented, where the start point of the NET signal is detected by computing the cross-correlation coefficient between the primary input and the ADF(Adaptive Digital Filter) output while the end point is detected by using the energy comparison method. The simulation results show that the convergence speed of the proposed adaptive echo canceller is faster than that of the conventional echo canceller and the cross-correlation coefficient yield more accurate detection of the start point of the NET signal.

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Kinematic Comparative Analysis of Short Turns between Skilled and Unskilled Alpine Skiers

  • Jo, Hyun Dai
    • 한국운동역학회지
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    • 제29권4호
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    • pp.219-226
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    • 2019
  • Objective: The purpose of this study is to provide a better understanding of short turn mechanism by describing short turns after kinematic analysis and provide skiers and winter sports instructors with data through which they are able to analyze right postures for turns in skiing in a systematic, rational and scientific manner. Method: For this, a mean difference of kinematic variables (ski-hip angle, ski-shoulder twist angle, pole checking angle, the center of gravity (CG) displacement, trunk forward lean angle) was verified against a total of 12 skiers (skilled and unskilled, 6 persons each), regarding motions from the up-start to down-end points for short turns. Results: There was no difference in a ski-hip twist angle. The ski-shoulder twist angle was large at the up-start point while a pole-checking angle was high at the down-end point in skilled skiers. Concerning the horizontal displacement of CG, skilled skiers were positioned on the right side at the upstart point. No significant difference was observed in the trunk forward lean angle. Conclusion: According to the ski-shoulder twist angle and CG horizontal displacement results, the upper body should be kept leant toward the pole. In addition, big turns should be made via edging and angulation. During pole checking, the hand holding the pole should be thrown and released toward a vector direction of the forearm.