• 제목/요약/키워드: on-line measurement

검색결과 1,874건 처리시간 0.057초

Improved spectral line measurements of the SDSS galaxy spectra

  • Oh, Kyu-Seok;Sarzi, Marc;Yi, Suk-Young
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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    • pp.35.1-35.1
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    • 2009
  • We have established a database of galaxy spectral line strengths for the SDSS database using an improved line measuring method. Our work includes the entire SDSS DR7 galaxies within redshift of 0.2. The absorption line strengths measured by the SDSS pipeline are seriously contaminated by emission filling. Our code, GANDALF (gas and absorption line fitting code) performs more accurate measurements by effectively separating emission lines from absorption lines. A significant improvement has also been made on the velocity dispersion measurement, more notably in late-type galaxies. We have also identified a number of broad line region galaxies which were misclassified as normal galaxies by the SDSS pipeline. We developed an effective method measuring their line strengths. The database will be provided with new parameters that are indicative of the line strength measurement quality. In addition, we made galaxy templates for the Hubble sequence. The database will be useful for many fields of galaxy studies including star formation and AGN activities.

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고압 회전기의 절연열화 진단을 위한 운전중 부분방전 측정 센서의 특성분석 (Characteristics Analysis of On-Line Partial Discharge Measurement Sensor for Insulation Diagnosis of HV Rotating Machines)

  • 윤대희;황돈하;김용주;이광식;김희동;김정우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1909-1911
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    • 2000
  • Recently many research activities on the diagnosis of stator winding insulation of large rotating machines have been reported. Capacitive couplers are widely used as sensors for on-line partial discharge (PD) measurement of high voltage rotating machines. This paper presents laboratory test to compare Stator Slot Coupler (SSC), Resistance Temperature Detector (RTD), 80 [pF] coupler and 500 [pF] coupler for on-line PD measurement of rotating machines.

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MEASUREMENT OF NUCLEAR FUEL ROD DEFORMATION USING AN IMAGE PROCESSING TECHNIQUE

  • Cho, Jai-Wan;Choi, Young-Soo;Jeong, Kyung-Min;Shin, Jung-Cheol
    • Nuclear Engineering and Technology
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    • 제43권2호
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    • pp.133-140
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    • 2011
  • In this paper, a deformation measurement technology for nuclear fuel rods is proposed. The deformation measurement system includes a high-definition CMOS image sensor, a lens, a semiconductor laser line beam marker, and optical and mechanical accessories. The basic idea of the proposed deformation measurement system is to illuminate the outer surface of a fuel rod with a collimated laser line beam at an angle of 45 degrees or higher. For this method, it is assumed that a nuclear fuel rod and the optical axis of the image sensor for observing the rod are vertically composed. The relative motion of the fuel rod in the horizontal direction causes the illuminated laser line beam to move vertically along the surface of the fuel rod. The resulting change of the laser line beam position on the surface of the fuel rod is imaged as a parabolic beam in the high-definition CMOS image sensor. An ellipse model is then extracted from the parabolic beam pattern. The center coordinates of the ellipse model are taken as the feature of the deformed fuel rod. The vertical offset of the feature point of the nuclear fuel rod is derived based on the displacement of the offset in the horizontal direction. Based on the experimental results for a nuclear fuel rod sample with a formation of surface crud, an inspection resolution of 50 ${\mu}m$ is achieved using the proposed method. In terms of the degree of precision, this inspection resolution is an improvement of more than 300% from a 150 ${\mu}m$ resolution, which is the conventional measurement criteria required for the deformation of neutron irradiated fuel rods.

용량성 부하를 고려한 옥내 전력선 채널 특성 측정 (Measurement of Indoor Power Line Channel Characteristics Considering Capacitive Loads)

  • 허윤석;홍봉화;김철;전계석;이대영
    • 대한전자공학회논문지TC
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    • 제42권6호
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    • pp.53-60
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    • 2005
  • 옥내$\cdot$외의 전력선 환경에 대한 정확한 채널 모델링에 관한 노력이 최근에 이루어지고 있다 알려진 일반 제한과 발표된 모델들은 특별한 형태의 접근들이었다. 본 논문은 더 신속하고 효율적인 전력선 통신 실험을 위한 전력선 채널 특성 측정에 관한 연구이다. 용량성 부하 시뮬레이터는 전력선 옥내 망 모뎀 개발에 필수적인 장비이다. 총 2:H가지 경우의 용량성 부하 변화에 대한 주파수 응답 특성 측정으로 채널 데이터 베이스화를 수행하였다. 본 측정 실험에서 전력선통신 채널은 보다 더 확정적인 매체라는 것을 확인하였다.

안모비대칭의 진단용 기준선의 유용성에 관한 연구 (A STUDY ON USEFULNESS OF THE REFERENCE LINE IN DIAGNOSIS OF THE FACIAL ASYMMETRY)

  • 류성호;장현호
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제31권3호
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    • pp.266-273
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    • 2005
  • Purpose: To assess the relationship between soft tissue reference line and hard tissue reference line using the standardized photographs and the posteroanterior cephalometric radiographs(P-A)in facial asymmetric patients and to compare the differences of angular measurement between normal group and asymmetry group. Methods: Normal group consisted of 44 persons with normal occlusion and normal facial morphology. Asymmetry group consisted of 90 patients with facial asymmetry. Standardized facial photographs and P-A were taken in all subjects. The horizontal reference lines were bipupillary line in photographs and latero-orbitale line in P-A respectively. The vertical reference line were the line from the midpoint of horizontal reference line perpendicularly. Angular measurement of otobasion canting, lip canting, nose deviation, chin deviation, and maxillary deviation were compared and analyzed in photographs. And angular measurement of mastoid canting, mandibular canting, nose deviation, chin deviation, and maxillary deviation were compared and analyzed in P-A. Results: 1. The variables of photographs and P-A were significantly related in the asymmetry group. 2. Significant differences between all variables except for PT2 and PA2 were shown in the asymmetry group and between PT1 and PA1, PT3 and PA3 in the normal group respectively. 3. Comparison measurement scores of angular difference between control group and experimental group concerning each variable showed significant difference except for PA1. Conclusions: Soft tissue components may not compensate for underlying skeletal imbalance in nose deviation and chin deviation. The horizontal reference lines in photographs were significant related with the P-A, but angular variables between the two studies show significant differences. Therefore, we do not recommend use photography in the assessment the facial asymmetry as complemented in the P-A.

배전기기 전압계측 정밀도 평가시스템 개발 및 성능시험 (A Development and Performance Test of Voltage Measurement Accuracy Assessment System for Distribution Equipment)

  • 조진태;김주용;이학주;김재한
    • 조명전기설비학회논문지
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    • 제27권9호
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    • pp.83-89
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    • 2013
  • Power distribution system has been changed from radial system to closed loop or mesh system due to connection of distributed generation growth. Data from distribution equipments which are installed at distribution line is required to be accurate for the performance of DMS(Distribution Management System). This paper analyzes the voltage measurement data from distribution equipment. However, the results of the analysis are confirmed to have some errors in voltage measurement data from distribution equipment. These errors come from aging of voltage sensor in distribution equipment and inaccurate data transfer to FRTU(feeder remote terminal unit) through the controller. The main problem is that the voltage measurement data of distribution equipment can not be assessed after it's first installation at the distribution line. The voltage measurement accuracy assessment system is to assess the voltage measurement data from distribution equipment on hot-line. This study had a field test to verify the performance of system.

종이 휨강성 자동 측정방식의 개발과 그 이용 - (2) 실험실 측정 (Development of on-line bending stiffness tester - (2) Lab experiment)

  • 서영범;정석면;정태영
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2007년도 춘계학술대회논문집
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    • pp.235-250
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    • 2007
  • A simple method of on-line stiffness measurement using the wrinkling behavior of paper web between rollers was presented. The theory and calculating equation were presented, and lab experiment was executed. We called the stiffness measured by Taber tester as 'Taber stiffness', and by tension wrinkling measurement as 'wrinkle stiffness', respectively, for comparison. Lab experimental results showed Taber and wrinkle stiffness are almost equivalent. We expect this method will work porperly for the on-line measurement of paper stiffness in near future.

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종이 휨강성 자동 측정방식의 개발과 그 이용 (2) - 실험실 측정 - (Development of On-line Bending Stiffness Tester (2) - Lab experiment -)

  • 서영범;정석면;정태영
    • 펄프종이기술
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    • 제39권4호
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    • pp.21-28
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    • 2007
  • A simple method of on-line stiffness measurement using the wrinkling behavior of paper web between two rollers was presented. The theory and the equation were presented, and lab and mill tests were executed. We called the stiffness measured by Taber tester as 'Taber stiffness', and by tension wrinkling measurement as 'wrinkle stiffness', respectively. Lab experimental results showed Taber and wrinkle stiffness are almost equivalent. In the mill experiment, we could measure the stiffness in the wet state and in the dry state. The dry wrinkle stiffness was close to the taber stiffness, but the wet wrinkle stiffness was much lower than the corresponding taber stiffness.

전력선통신모뎀의 전자계강도 측정방법 연구 (A Study for the Measurement Method of Electromagnetic Field Strength of Power Line Communications Modem)

  • 장동원
    • 한국정보통신설비학회:학술대회논문집
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    • 한국정보통신설비학회 2006년도 하계학술대회
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    • pp.162-165
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    • 2006
  • This paper describes a measurement method for electromagnetic field strength of power-line communications(PLC) modem. First it outlines the technology used in PLC modems, and the technical regulation being offered to the technology, from the point of view of its effect on electromagnetic compatibility (EMC). The radio spectrum needs protection from other interferers, and there is a regime in place to provide this protection. Difficulties in achieving compatibility between the requirements for radio protection and the requirements for operation of the PLC modem mean that there is no consensus as yet as to how PLC modem components can be made compliant with EMC requirements globally. It is concluded that there is a measurement method according to CISPR standards which satisfy requirements in domestic regulation.

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FBG 센서를 활용한 온도와 스트레인 변화 모니터링 (Monitoring of Temperature and Strain Variation with FBG Sensors)

  • 고기한;박영;조용현;정호성;조용석;최원석
    • 한국전기전자재료학회논문지
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    • 제22권3호
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    • pp.218-221
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    • 2009
  • This paper reports on measurement method for the fiber optic strain monitoring of overhead contact line systems of trains, We used FBG (Fiber Bragg Grating) sensors to measure the strain variation of overhead contact line. FBG sensors can sensitively measure the variation of strain and! or temperature by the shift wavelength of reflected wave according to the lattice variation during the measurement. FBG sensor were attached on the contact line and connected to the monitoring system with optical fibers. The monitering system with FBG sensors showed very good sensitivity to measuring strain variation and this system could be applied to the overhead contact line of KTX (Korea Train eXpress).