• 제목/요약/키워드: Signal profile

검색결과 406건 처리시간 0.031초

동적 Range 검출에 의한 원료 Pile 형상 관리 시스템 (Profile Management System of Material Piles by Dynamic Range Finding)

  • 안현식
    • 융합신호처리학회 학술대회논문집
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    • 한국신호처리시스템학회 2000년도 하계종합학술대회논문집
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    • pp.333-336
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    • 2000
  • In this paper, a profile management system consisting of global and local range finders is presented for the automat ion of material pile handling. A global range finder detects range data of the front part of the piles of material and a profile map is obtained from a 3D profile detection algorithm. A local range finder attached on the side of the arm of the reclaimer detects range data with the handling function dynamically, and a local profile patch is acquired from the range data A yard profile map manager constructs a map by using the 3D profile of the global range finder and revises the map by replacing it with the local profile patch obtained Iron the local range finder. The developed vision system was applied to a simulator and the results of test show that it is appropriate to use for automating the material handling.

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THE MASS PROFILE OF ABELL 1689 FROM A LENSING ANALYSIS OF DEEP WIDE FIELD SUBARU IMAGES

  • UMETSU KEIICHI;BROADHURST TOM;TAKADA MASAHIRO;KONG Xu
    • 천문학회지
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    • 제38권2호
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    • pp.191-195
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    • 2005
  • We used Subaru observations of A1689 (z = 0.183) to derive an accurate, model-independent mass profile for the entire cluster, r$\le$2Mpc/h, by combining magnification bias and distortion measurements. The projected mass profile steepens quickly with increasing radius, falling away to zero at r${\~}$1.0Mpc/h, well short of the anticipated virial radius. Our profile accurately matches onto the inner profile, r $\le$200kpc/ h, derived from deep HST / ACS images. The combined ACS and Subaru information is well fitted by an NFW profile with virial mass, $(1.93 \pm 0.20) {\times}10^{15} M_{\bigodot}$, and surprisingly high concentration, $C_{vir} = 13.7^{+1.4}_{-1.1}$, significantly larger than theoretically expected ($C_{vir} {\le}4$), corresponding to a relatively steep overall profile. These results are based on a reliable sample of background galaxies selected to be redder than the cluster E/SO sequence. By including the faint blue galaxy population a much smaller distortion signal is found, demonstrating that blue cluster members significantly dilute the true signal for r $\le$ 400kpc/ h. This contamination is likely to affect most weak lensing results to date.

디지털 필터링을 이용한 마멸량 계산 (The Calculation of the Amount of Wear using Digital Filtering)

  • 전종하;구영필;조용주
    • Tribology and Lubricants
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    • 제16권2호
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    • pp.133-137
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    • 2000
  • A new method to calculate the wear amount using surface profile signal was suggested. It takes advantage of filtering technic to estimate the original surface profile of wear track precisely. The original profile of wear track was estimated by comparing with outside of wear track. The estimated surface profile was well fitted to the original profile assumed unknown.

주파수 변조를 이용한 MR DANTE 고속 영상법 (DANTE Fast MR imaging Using Frequency Modulation)

  • 노용만;정성택;홍인기;조장희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1995년도 춘계학술대회
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    • pp.42-44
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    • 1995
  • The original DANTE sequence and its variations have limitation in excitation profile (a sinc function-like excitation) due to the finite duration of the DANTE pulsetrain. This sinc function-like selection profile excites only a small fraction of the spins in the pixel thereby results in poor signal to noise ratio (only about ${\sim}1%$ of normal MR imaging sequence). Therefore, this poor signal to noise ratio (SNR) has been the main drawback of the original DANTE sequence. To improve the signal to noise ratio, phases of individual RF pulses in the DANTE pulse train were modulated so that more spins in the object were excited ($1{\sim}3$). We have introduced a new FM (Frequency Modulation) DANTE sequence and analyzed the signal intensity and excitation profiles.

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파형 분석을 위한 멕시코 모자 함수 응용 (Application of Mexican Hat Function to Wave Profile Detection)

  • 이희성;권순홍;이태일
    • 한국해양공학회지
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    • 제16권6호
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    • pp.32-36
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    • 2002
  • This paper presents the results of wave profile detection from video image using the Mexican hat function. The Mexican hat function has been extensively used in the field of signal processing to detect discontinuity in the images. The analysis was done on the numerical image and video images of waves that were taken in the small wave flume. The results show that the Mexican hat function is an excellent tool for wave profile detection.

불균일 자장 보정 후처리 기법을 이용한 간 영상에서의 지방 및 $T_2{^*}$ 측정 (Background Gradient Correction using Excitation Pulse Profile for Fat and $T_2{^*}$ Quantification in 2D Multi-Slice Liver Imaging)

  • 남윤호;김한성;조상영;김동현
    • Investigative Magnetic Resonance Imaging
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    • 제16권1호
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    • pp.6-15
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    • 2012
  • 목적: 이 연구의 목적은 excitation pulse profile을 이용하여 불균일 자장에 의하여 발생하는 배경 경사 자장에 의한 영향을 보상하여 2차원 다중 단면 경사에코 간 영상에서의 정확한 지방 및 $T_2{^*}$ 측정을 하는 데에 있다. 대상과 방법: 2차원 경사에코영상에서 불균일 자장에 의한 배경경사자장으로 인하여 유도되는 신호의 감소는 excitation pulse profile weighting으로 나타난다. 이에 의한 영향을 최소화 하기 위하여 $B_0$ field map을 통하여 단면선택방향으로의 선형 경사자장의 정도를 추정한 후, 획득한 신호를 excitation pulse profile을 이용하여 보정하였다. $T_2{^*}$ 및 지방은 보정된 신호로부터 측정되었으며 보정방법은 3.0T 임상용 장비에서 팬텀 및 in vivo 실험을 통하여 이루어 졌다. 결과: 팬텀 실험 결과는 보정 후 측정된 $T_2{^*}$ 및 지방의 양이 자장이 균일한 경우에 가까워 진 것을 보여 주었다. In vivo 실험에서는 간에서 배경경사자장의 크기가 약 120 ${\mu}T/m$ 정도 까지로 나타났으며 보정하기 전에 비하여 측정된 $T_2{^*}$ 및 지방의 정도의 균일도가 높아지는 것을 확인할 수 있었다. 결론: Excitation pulse profile을 이용한 배경경사자장 보정 방법은 경사 에코 신호에서의 거시적인 불균일 자장에 의한 영향을 줄여 주며 2차원 간 영상에서의 적용을 통하여 보다 정확한 지방 및 $T_2{^*}$의 측정에 도움이 될 수 있다.

전자기 토모그래피를 이용한 액체 금속 속도장 측정 (Measurement of Velocity Profile in Liquid Metal Flow Using Electromagnetic Tomography)

  • 최상호;안예찬;김무환
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1749-1754
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    • 2004
  • In order to measure non-intrusively velocity profile in liquid metal flow, a modified electromagnetic flowmeter was designed, which was based on electromagnetic tomography technique. Under the assumption that flow is fully-developed, axisymmetric and rectilinear, the velocity profile was reconstructed after the flowmeter equation, the first kind of Fredholm integration equation, was linearized. In reconstruction process Tikhonov regularization method with regularization parameter was used. The reconstructed velocity profile had the nearly same as turbulent flow profile which was approximately represented as log law. In addition, flowmeter output for a fixed magnet rotation angle was linearly proportional to flow rate. When magnet rotation angle was $54^{\circ}$, axisymmetric weight function was nearly uniform so that the flowmeter gives a constant signal for any fully-developed, axisymmetric and rectilinear profile with a constant flow rate.

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MR DANTE 고속 영상에서 SNR의 개선에 관한 연구 (Improvement of SNR in DANTE Fast MR Imaging)

  • 정성택
    • 대한의용생체공학회:의공학회지
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    • 제18권1호
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    • pp.87-96
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    • 1997
  • A pixel profile in the conventional DANTE sequence is so poor that the excited area by DANTE sequence is a small portion of a pixel. This causes poor signal to noise ratio in DANTE image. In this paper, a frequency modulated(FM) DANTE imaging sequence is proposed to improve pixel profile in DANTE image. A DANTE pulse train is shaped by an FM function so that all the spins within a pixel are excited, thereby improving the signal to noise ratio. It also shows that the pixel profiles are dependent on the sweep in FM signal. Computer simulations and experimental result obtained using a 7.0 T NMR imaging system are presented.

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고압 수은등의 온도분포 측정에 대한 연구 (A study on the temperature distribution measurement of the high pressure mercury lamp)

  • 손승현;김상용;김창섭;지철근
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 1990년도 추계학술발표회논문집
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    • pp.35-40
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    • 1990
  • Temperature distribution of high pressure mercury lamp has been mesured as a function of time using spectroscopic method. Sampling signal which is synchronized by lamp voltage was used to mesure temporal line intensity at each radius. To obtain radial temprature distribution, the mesured intensity was transformed into radial line intensity by Abel's formula. Absolute temperature profile was calculater from relative intensities of spectral lines as a function of line and tube radius. The temperature profile is very similar to the electrical tube current profile.

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Flexible 3-dimension measuring system using robot hand

  • Ishimatsu, T.;Yasuda, K.;Kumon, K.;Matsui, R.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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    • pp.700-704
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    • 1989
  • A robotic system with a 3-dimensional profile measuring sensor is developed in order to measure the complicated shape of the target body. Due to this 3-dimensional profile measuring sensor, a computer is able to adjust the posture of the robot hand so that complicated global profile of the target body can be recognized after several measurements from the variant directions. In order to enable fast data processing, a digital signal processor and a look-up table is introduced.

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