• 제목/요약/키워드: real-time measurement

검색결과 2,165건 처리시간 0.039초

실시간 지중 전력케이블 용량 평가를 위한 토양 열 특성 및 온도 측정 시스템 개발 (Development of the Soil Thermal Property and Temperature Measurement System for the Real-time Ampacity Estimation of Underground Power Cables)

  • 정성환;김대경;최상봉
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 A
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    • pp.22-24
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    • 2002
  • This paper introduces the real-time soil thermal property analyzer and temperature measuring system which is combined with radio telecommunication technique. To measure the thermal parameters in real-time, the radio telecommunication technique are used the personal communication service (PCS) which is in the world-wide serviced commercially firstly by CDMA. The thermal property analyzer has an ability of measuring thermal resistivity, thermal diffusivity and thermal stability. To estimate the soil thermal properties, the curve fitting algorithm by means of the least square method are used. TCP/IP protocol and MTM are used to install the real-time soil thermal property and temperature measurement system at multiple locations along routes of the underground power cables and to reduce the cost of telecommunication.

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확장 트와이만-그린 간섭계를 이용한 운동 오차의 실시간 보상 (Real-time Compensation of Motion Errors Using Extended Twyman-Green Interferometry)

  • 배은덕;오정석;김승우
    • 한국정밀공학회지
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    • 제20권10호
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    • pp.112-119
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    • 2003
  • This paper presents an extended Twyman-Green interferometry that enables simultaneous and real-time measurement of 5-DOF motion errors of the translational moving stage. This method uses a null balancing technique in which two plane mirrors are used as target mirrors to generate an interferometric fringe utilizing the optical principles of Twyman-Green interferometry. Fringe is detected by 2D photodiode array for high-speed measurement. Errors are then independently suppressed by activation of piezoelectric actuators through real-time feedback control while the machine axis is moving. Experimental results demonstrate that a machine axis can be controlled with motion errors about 10 nm in linear displacement, 0.15 arcsec in angular displacement.

의사결정나무를 이용한 비즈니스 프로세스의 실시간 위험 수준 측정 (Real-time Risk Measurement of Business Process Using Decision Tree)

  • 강복영;조남욱;김훈태;강석호
    • 산업경영시스템학회지
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    • 제31권4호
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    • pp.49-58
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    • 2008
  • This paper proposes a methodology to measure the risk level in real-time for Business Activity Monitoring (BAM). A decision-tree methodology was employed to analyze the effect of process attributes on the result of the process execution. In the course of process execution, the level of risk is monitored in real-time, and an early warning can be issued depending on the change of the risk level. An algorithm for estimating the risk of ongoing processes in real-time was formulated. Comparison experiments were conducted to demonstrate the effectiveness of our method. The proposed method detects the risks of business processes more precisely and even earlier than existing approaches.

화상처리에 의한 XLPE의 트리잉 해석 (An Analysis on Treeing in XLPE by means of Image Processing)

  • 이재봉;임장섭;정우성;김태성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1994년도 추계학술대회 논문집
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    • pp.122-128
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    • 1994
  • Studies on treeing phenomena have depended on the visual measurement using optical microscope. In the visual measurement, it is difficult to analyze the treeing in real time because voltages are applied discontinuously and impossible to calculate the deterioated area by treeing. Only tree type and length are studied. In this paper, image processing is introduced and voltages are applied continuously. The tree length and area are calculated in real time from tree inception to breakdown. Growing characteristics about tree types are compared for the normalized breakdown time.

무선센서 네트워크 계측을 이용한 저수지 및 제방 계측시스템 구축에 관한 기초연구 (Basic Study on Monitoring System of Reservoir and Leeve Using Wireless Sensor Network)

  • 유찬호;김익훈;이승주;황정순;백승철
    • 한국지반환경공학회 논문집
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    • 제19권1호
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    • pp.25-30
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    • 2018
  • 저수지 및 제방에서의 계측은 가장 높이가 높은 구간을 선정하여 계측기를 매설하고 측정하는 집중계측 방식으로 최근에는 자동화 계측기술이 발달되어 실시간으로 계측결과가 관리사무소로 전달 및 수집, 저장되고 있다. 실시간 계측기술이 발달되었음에도 불구하고 계측결과가 시설물 관리와는 직접적으로 이용되지 못하고 있다. 최근 사물인터넷 기반의 무선 센서 네트워크 계측기술이 발달함에 따라 본 연구에서는 저수지 및 제방 구조물에 무선센서 네트워크 기술을 기반의 실시간 계측 및 평가시스템을 제안하였다. 적용성 평가를 위한 침투해석 결과 저수위 변화에 따라 제체 내부의 침윤선 변화와 함께 토체의 체적함수비가 함께 변화하여 체적함수비를 센서 노드로 설정한 계측시스템의 적용성을 확인하였다.

국지측량에서의 현장 Calibration에 의한 RTK-GPS 정확도 분석 (The Accuracy Analysis of RTK-GPS by Field Calibration in Plane Surveying)

  • 박운용;신동수
    • 대한공간정보학회지
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    • 제10권2호
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    • pp.87-95
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    • 2002
  • 실시간 동적(Real Time Kinematic) GPS는 실시간으로 높은 정밀도의 위치결정을 가능케 해준다. 만약 미지정수를 구하기 위하여 정수해를 사용한다면 수 mm의 정확도를 얻을 수 있고, 실 수해를 얻는다면 수십 cm 의 정확도를 얻을수 있다. 본 연구에서는 통일 측점에 대해 기존의 재래식 측량기법(Total Station), 정적(Static) 상대측위 GPS기법과 현장 Calibration에 의한 실시간 동적(Real Time Kinematic) GPS기법에 의해 측량을 수행하여 각 기법별 측정의 정확도 등을 비교 분석하여 현장 Calibration에 의한 실시간 동적 (Real Time Kinematic) GPS기법의 정확도를 분석고자 한다. 국소지역에서 기존의 실시간 동적(Real Time Kinematic) GPS방식을 보완한 현장 Calibration에 의한 실시간 동적(Real Time Kinematic) GPS 측량을 수행한 결과, 미지정수해의 고정해를 얻지 못하는 경우를 제외하고는 모두 6cm 이하의 오차가 나타났고, Control Point의 측점수를 3개와 4개로 변화시켜 실시간 동적(Real Time Kinematic) GPS 측량을 수행한 결과 두 측정치의 차이는 최대 3cm로 나타났다. 최종적으로 국소지역에서도 현장 Calibration에 의한 실시간 동적(Real Time Kinematic) GPS기법이 사용가능함을 알 수 있었다.

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프린지 투영법을 이용한 실시간 3D 구강 내 스캐너의 개발 (Development of a Real-time 3D Intraoral Scanner Based on Fringe-Projection Technique)

  • ;이건수;박강
    • 한국CDE학회논문집
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    • 제17권3호
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    • pp.156-163
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    • 2012
  • Real-time three-dimensional shape measurement is becoming increasingly important in various fields, including medical sciences, high-technology industry, and microscale measurements. However, there are not so many 3D profile tools specially designed for specifically narrow space, for example, to scan the tooth shape of a human jaw. In this paper, a real-time 3D intraoral scanner is proposed for the measurement of tooth profile in the mouth cavity. The proposed system comprises a laser diode beam, a micro charge-coupled device, a graticule, a piezoelectric transducer, a set of optical lenses, and a polhemus device sensor. The phase-shifting technique is used along with an accurate calibration method for the measurement of the tooth profile. Experimental and theoretical inspection of the phase-to-coordinate relation is presented. In addition, a nonlinear system model is developed for collimating illumination that gives the more accurate mathematical representation of the system, thus improves the shape measurement accuracy. Experiment results are presented to verify the feasibility and performance of the developed system. The experimental results indicate that overall measurement error accuracy can be controlled within 0.4 mm with a variability of ${\pm}0.01$.

Real-Time Power Electronics Remote Wiring and Measurement Laboratory (PermLAB) Using 3-D Matrix Switching Algorithms

  • Asumadu, Johnson A.;Tanner, Ralph;Ogunley, Hakeem
    • Journal of Power Electronics
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    • 제10권6호
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    • pp.611-620
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    • 2010
  • This paper presents a new architecture, called "Power Electronics Remote Wiring and Measurement Laboratory (PermLAB)", that translates a common gateway interface (CGI) string from a remote web user to a web server connected to a 3-dimension switching matrix board, can be used to switch on and off, and to control a cluster of instruments and components. PermLAB addresses real-time connection, switching, and data acquisition over the Internet instead of using simulated data. A software procedure uses a signature system to identify each instrument and component in a complex system. The Web-server application is developed in HTML, JavaScript and Java, and in C language for the CGI interface, which resides in a controller portion of LabVIEW. The LabVIEW software fully integrates the Web sever, LabVIEW data acquisition boards and controllers, and the 3-dimensional switching matrix board. The paper will analyze a half-wave rectifier (AC - DC converter) circuit connected over the Internet using the PermLAB. PermLAB allows students to obtain real data by real-time wiring of real circuits in the laboratory using a "virtual breadboard" on the Web. The software for the Web-based 3-dimensional system is flexible, portable, can be integrated into many laboratory applications or expanded, and easily accessible worldwide.

수동 센서의 오차 최소화를 이용한 실시간 DSC 자동초점 시스템 설계 (A Design of Real-time Automatic Focusing System for Digital Still Camera Using the Passive Sensor Error Minimization)

  • 김근섭;김덕영;김성환
    • 대한전기학회논문지:시스템및제어부문D
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    • 제51권5호
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    • pp.203-211
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    • 2002
  • In this paper, the implementation of a new AF(Automatic Focusing) system for a digital still camera is introduced. The proposed system operates in real-time while adjusting focus after the measurement of distance to an object using a passive sensor, which is different from a typical method. In audition, measurement errors were minimized by using the data acquired empirically, and the optimal measuring time was obtained using EV(Exposure Value) which is calculated from CCD luminance signal. Moreover, this system adopted an auxiliary light source for focusing in absolute dark conditions, which is very hard for CCD image Processing. Since this is an open-loop system adjusting focus immediately after the distance measurement, it guarantees real-time operation. The performance of this new AF system was verified by comparing the focusing value curve obtained from AF experiment with the one from the measurement by MF(Manual-Focusing). In both case, edge detector was used for various objects and backgrounds.