• Title/Summary/Keyword: 거리측정

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Design of Counter Circuit for Improving Precision in Distance Measuring System (거리 측정 시스템의 정밀도 향상을 위한 카운터 회로의 설계)

  • Choi, Jin-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.7
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    • pp.885-890
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    • 2020
  • In the distance measurement system the time-to-digital conversion circuit used measures the distance using the time interval between the start signal and the stop signal. The time interval is generally converted to digital information using a counter circuit considering the response speed. Therefore, a clock signal with a high frequency is required to improve precision, and a clock signal with a high frequency is also required to measure fine distances. In this paper, a counter circuit was designed to increase the accuracy of distance measurement while using the same frequency. The circuit design was performed using a 0.18㎛ CMOS process technology, and the operation of the designed circuit was confirmed through HSPICE simulation. As a result of the simulation, it is possible to obtain an improvement of four times the precision compared to the case of using a general counter circuit.

Measurement and Prediction of the Visibility Range by the Variations of the Character Sizes and Illuminance (글자 크기와 조도의 변화에 의한 가시거리 측정과 예상)

  • Kim, Tae-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8222-8227
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    • 2015
  • The visibility range is defined from where one can see, which can be changed by the character sizes and illuminances and so on, which of one-hundred and twelve students are measured for three illuminances and three character sizes in this paper. In determining the character sizes and illuminances, the visibility range can be an important data. Functions are proposed whose independent variable is illuminance and whose dependent variable is visibility range in order to predict the visibility range of unmeasured illuminances. The fractional functions are used for three character sizes because the visibility range is invariant according to illuminance. There are three parameters to be determined - k, m, n, which are selected based on the measured visibility ranges. Because the visibility ranges of three character sizes are measured, three k's can be calculated. In this paper the case of minimum variance of three k's is selected, and three parameters - k,m,n- of that case is selected. The three functions according to three character sizes are proposed. The small differences between the measured data and the postulated functions verifies the accuracy of the functions.

An Efficient Facial Expression Recognition by Measuring Histogram Distance Based on Preprocessing (전처리 기반 히스토그램 거리측정에 의한 효율적인 표정인식)

  • Cho, Yong-Hyun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.5
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    • pp.667-673
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    • 2009
  • This paper presents an efficient facial expression recognition method by measuring the histogram distance based on preprocessing. The preprocessing that uses both centroid shift and histogram equalization is applied to improve the recognition performance, The distance measurement is also applied to estimate the similarity between the facial expressions. The centroid shift based on the first moment balance technique is applied not only to obtain the robust recognition with respect to position or size variations but also to reduce the distance measurement load by excluding the background in the recognition. Histogram equalization is used for robustly recognizing the poor contrast of the images due to light intensity. The proposed method has been applied for recognizing 72 facial expression images(4 persons * 18 scenes) of 320*243 pixels. Three distances such as city-block, Euclidean, and ordinal are used as a similarity measure between histograms. The experimental results show that the proposed method has superior recognition performances compared with the method without preprocessing. The ordinal distance shows superior recognition performances over city-block and Euclidean distances, respectively.

A Sensor Positioning Scheme using Region Distance Evaluation in Non-Uniform Wireless Sensor Networks (비 균일 무선 센서 네트워크에서 지역 거리 평가 기반의 센서 위치 측정 기법)

  • Park, Hyuk;Hwang, Donggyo;Park, Junho;Seong, Dong-ook;Yoo, Jaesoo
    • Proceedings of the Korea Contents Association Conference
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    • 2012.05a
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    • pp.33-34
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    • 2012
  • 무선 센서 네트워크의 다양한 응용에 있어 센서 노드의 지리학적 위치 측정은 매우 중요하다. 이를 위해 비-거리(Range-Free) 기반 위치 측정 기법에 대한 연구가 활발하게 진행 중이며, 비 균일 네트워크 환경에서 위치 정확도를 향상하기 위한 밀집 확률 기반의 위치 측정 기법이 제안되었다. 밀집 확률 기반의 위치 측정 기법에서 추정 거리 산출 시 노드 통신 반경 내 1-홉 거리는 모두 동일한 값을 갖는데 이는 반경 내 가까운 이웃 노드와 먼 이웃 노드가 있어도 모두 같은 거리로 추정하기 때문에 위치 측정 시 오차가 발생 할 수 있다. 따라서 본 논문에서는 이러한 오차를 줄이기 위해 각 노드마다 거리 추정 후 센싱 반경을 조절하여 2차 지역 거리 평가를 통해 센서의 위치를 측정하는 기법을 제안한다. 성능평가 결과, 제안하는 기법이 기존 기법에 비해 측위 정확도가 크게 향상되었다.

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A study on Location Positioning System using RF Radio and Vision (무선 RF 및 비젼을 이용한 위치인식시스템 연구)

  • Kim, Tae-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.8
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    • pp.1813-1819
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    • 2011
  • In this research, the location positioning system supposed is concerned with range recognition technology using phase and magnitude of radio wave and adding technology of image histogram by vision. By the proposed technology, we design the radio transmitter and receiver and realize the measurement system, and save the data in disk that is earned from 900Mhz RF signal, middle frequency 450Khz of analog signal. Range information is earned the data through digital signal processing of IF signal. For the estimation of range measured, we analyze the difference between real range and measurement range, and also suggest the method to improve the measurement error using average processing and amplitude properties.

Study on Golf Range Finder by using Biprism Theory of Keratometer (케라토미터의 바이프리즘 원리를 이용한 골프거리측정기에 관한 연구)

  • Cha, Jung-Won
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.4
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    • pp.495-501
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    • 2013
  • Purpose: This study was to develop golf range finder which could measure exact distance from golfer to flag by using telescope and biprism. Methods: Golf range finder was made that included telescope and biprism which could move in the telescope, and an accuracy of the range finder was analyzed in distance range 20~200 m. Results: An equation was made for measuring distance which was related at position of biprism, and we could measure distance successfully by using developed golf range finder. Biprism of 2 ${\Delta}$ was useful to measure in short distance but it had bad accuracy in long distance, and 0.5 ${\Delta}$ was more useful in long distance. Image got worse when the biprism approch to focal point of objective lens for measurement in long distance, so we developed multi-layer biprism to prevent the weak point. Conclusions: Image stabilization by biprism for measuring distance was confirmed. Even if hand was moving, the distance could be measured well by using biprism, and we could find that the induced equation for distance measurement was useful. We found that multi-layer biprism, which is was new developed, was more useful than general biprism when the biprism approched to focal point of objective lens for measurement in long distance.

Simulations for Measuring the Optical Axis outside Objects in Stereo Vision System (스테레오 비전 시스템에서 광축 외부 물체 측정을 위한 시뮬레이션)

  • Kim, Eun-Ju;Lee, Byung-Soo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.04a
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    • pp.330-333
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    • 2010
  • 본 논문은 인간의 시각체계를 모방한 스테레오 비전 시스템을 이용해 물체까지의 거리를 측정하는 방법을 제안한다. 기존 연구에서의 거리 측정 방법은 스테레오 카메라의 중복 영역 중에서 광축 내부에 물체가 위치했을 경우에만 측정 가능하다는 단점이 있다. 그래서 본 논문에서는 두 카메라의 중복영역 중에서 광축 외부에 물체가 위치했을 경우에 그 물체까지의 거리를 측정하는 방법을 제안 한다. 본 논문에서 제안한 거리 측정 방법을 확인하기 위해 시뮬레이션을 실행하였다. 시뮬레이션 실험 결과 제안된 거리 측정 방법의 정확성을 확인하였다.

A long Distance Measurement Scheme with a Large Aperture Lens Based on Infrared Stereo Vision System for Ship Navigation Safety (선박 안전운항용 대구경 렌즈 적외선 스테레오비전 시스템의 거리 측정 기법)

  • Oh, M.K.;Heo, Y.S.;Kang, H.S.;Kim, Y.S.;Kim, S.K.
    • Electronics and Telecommunications Trends
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    • v.28 no.6
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    • pp.127-132
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    • 2013
  • 본 논문에서는 야간 및 해무 상태에서 선박의 안전 운항을 지원할 수 있는 해상 적외선 스테레오비전 대구경 감시 시스템용 거리 측정 기법을 제안하였다. 선박의 안전 운항을 위한 감시 시스템에는 스테레오비전 정보를 이용하여 거리를 측정하는 알고리즘이 필요하며 물체의 이미지 및 물체까지의 거리정보를 디스플레이 하는 기능을 구현하였다. 원거리 측정 및 야간 측정 기능을 구현하기 위해 적외선 스테레오비전 및 대구경 렌즈를 이용하였으며, 행상에서 파고에 의한 흔들림으로 이미지의 연속적인 처리가 어려운 측면이 있어 물체의 비전 정보를 이용하여 거리를 계산하는 알고리즘 및 계산된 거리 정보를 디스플레이하는 프로그램을 개발하였다. 이러한 실험 결과가 선박 안전운항을 위한 유용한 시스템이 될 것으로 예상하고 있다.

A Study on the Optimal Operation of Satellite Range Measurement for KOMPSAT II (다목적실용 위성 2호의 위성 거리 측정 최적 운용 방안 연구)

  • Kim, Young-Wan;Ahn, Sang-Il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.1
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    • pp.31-37
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    • 2010
  • Based on the analyses of satellite range measurement, the optimal operation for satellite range measurement of KOMPSAT II, which operates in the low-earth orbit, was proposed in this paper. The orbital motion of the satellite was analyzed in viewpoints of radial velocity, acceleration and speed of acceleration. Correspondingly the effects for satellite ranging signal due to satellite motion were analyzed in viewpoints of doppler phenomena, which are doppler frequency, doppler rate and speed of doppler rate. The accuracy and ambiguity probability of the satellite range measurement were quantitatively analyzed under various circumstances. The optimal operation parameters for satellite range measurement were also analyzed based on the analyzed results. The analyzed results in this paper can be utilized in design of small-sized ground station for satellite range measurement.

Design and Implementation of a Distance Measurement System using Radar Sensor (레이더 센서를 이용한 거리 측정 시스템의 설계 및 구현)

  • Jang, Si-woong;Jung, Dong-hun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.7
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    • pp.1009-1014
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    • 2018
  • In this paper, we have designed and implemented a system that utilizes a radar sensor to measure distance between a sensor and objects. The sensor module creates raw data and uploads the data on the distance measuring system, which detects the presence of objects by using standard deviation and average filters. The experiment found that an algorithm using average filters measured people with error rates of up to 9.7 meters and a maximum error rate of 0.02 meters or less. While in an algorithm using standard deviations, it was found that an object is measured at an error rate of up to a maximum distance of 9.7 meters and a maximum error rate of 0.15 meters. Therefore, we have concluded that if a distance was measured by using a radar sensor, algorithms using average filters resulted in a higher accuracy than standard deviations filters.