• Title/Summary/Keyword: Distance measurement

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A Code Correlation Type RF Short Range Measurement System for High-Speed Mobile Targets (고속 이동체에 대한 전파형 코드상관방식 근거리 측정 시스템)

  • Lim, Tae-Wook;Lee, Seok-Woo;Jung, Jong-Chul
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2430-2432
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    • 1998
  • Generally, in the best-known Pulse-type type and Frequency Modulated Continuous Wave(FM/CW)-type RF range measurement systems, the nearest measurable distance between antenna of system and targets is limited to several tens of meters. Moreover, in case of high-speed targets it is more difficult to measure the distance precisely. In this paper we design our own RF(X-band) range(up to 15 meters) measurement system usi code correlation for high- speed targets. It 0 the correlation value between transmitting receiving PN (Pseudo -Noise) codes. So we determine the distance between antenna of s and targets using this correlation value. We fabricated it using MIC techniques and experimental results show that the proposed syste fully qualified for a short range measurement syste

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A Study on Distance Calculation Revision Algorithm using the Filtering of RSSI Measurement Results (RSSI 측정결과 필터링을 이용한 거리계산 보정 알고리즘에 관한 연구)

  • Kim, Ji-seong;Kim, Yong-kab
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.1
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    • pp.25-31
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    • 2017
  • The indoor location based service proposed in the study was assigned to target a moving user. Positioning in the outdoor environment is accurate while using GPS. However, in an indoor environment, positioning is inaccurate and difficult. In order to overcome this, studies of various techniques for positioning based on wireless communication such as Wi-Fi, Zigbee and Bluetooth are being performed. The RSSI value and the delivery signal of the bluetooth beacon are measured according to the distance, and to a database. It was applied calculating the value for the average RSSI and the RSSI filtering feedback. Filtering is used to reduce the error of the RSSI values that are measured at long distance. When average and feedback filtering coefficient are set with 0.5, irregular and highly RSSI values are decreased. As the distance increases, the range of error is confirmed to have a reduction when using a distance calculation correction algorithm. Finally, when using the RSSI measurement results filtering, it corrects an unstable signal. Also, the distance correction algorithm is used to reduce a range of errors.

High-Accuracy Coastdown Test Method by Distance-Time Measurement: II. Development of a Short Distance Method and its Evaluation (거리·시간 측정에 의한 고정도 타행시험법: II. 단거리 방법의 개발 및 시험)

  • Hur, N.G.;Ahn, I.K.;Petrushov, V.A.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.3
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    • pp.1-8
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    • 1995
  • In the companion paper of the present paper, a coast down test method to determine the resistance forces on running vehicle based on the distance-time measurement was explained along with the suggestions to improve its accuracy and testing methodology. In the present paper some of the suggestions discussed previously are implemented and actually road tested to see the applicability of the improved method(short distance method) in the field. From the results. it is shown that the short distance method which requires only 600m long proving ground road gives at least comparable results on the accuracy compared to the original S-t method which requires 2000m. It is hoped that the present method be further refiend to give more accurate results.

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Application of slab and plate width measurement using laser distance meter (Laser를 이용한 후물 판재류 및 Slap폭 측정 적용)

  • 최철호
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1076-1078
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    • 1996
  • According to ascending needs for quality assurance of plate by customer and automated measurement of dimension for slab, in plate mill, project is on preceeding to install measuring system to measure width, length and camber of slab and plate using laser distance meter. In this document, I will describe not technical point of view but idea of design for installation system.

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Distance measurement technique using a mobile camera for object recognition (객체 인식을 위한 이동형 카메라를 이용한 거리 측정 기법)

  • Hwang, Chi-gon;Lee, Hae-Jun;Yoon, Chang-Pyo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.05a
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    • pp.352-354
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    • 2022
  • Position measurement using a camera has been studied for a long time. This is being studied for distance recognition or object recognition in autonomous vehicles, and it is being studied in the field of indoor navigation, which is a limited space where GPS is difficult to apply. In general, in a method of measuring the distance using a camera, the distance is measured using a distance between the cameras using two stereo cameras and a value measured through a captured image or photo. In this paper, we propose a method of measuring the distance of an object using a single camera. The proposed method measures the distance by using the distance between cameras, such as a stereo camera, and the value measured by the photographed picture through the gap of the photographing time and the distance between photographing.

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Improving Phoneme Recognition based on Gaussian Model using Bhattacharyya Distance Measurement Method (바타챠랴 거리 측정 기법을 사용한 가우시안 모델 기반 음소 인식 향상)

  • Oh, Sang-Yeob
    • Journal of Korea Multimedia Society
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    • v.14 no.1
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    • pp.85-93
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    • 2011
  • Previous existing vocabulary recognition programs calculate general vector values from a database, so they can not process phonemes that form during a search. And because they can not create a model for phoneme data, the accuracy of the Gaussian model can not secure. Therefore, in this paper, we recommend use of the Bhattacharyya distance measurement method based on the features of the phoneme-thus allowing us to improve the recognition rate by picking up accurate phonemes and minimizing recognition of similar and erroneous phonemes. We test the Gaussian model optimization through share continuous probability distribution, and we confirm the heighten recognition rate. The Bhattacharyya distance measurement method suggest in this paper reflect an average 1.9% improvement in performance compare to previous methods, and it has average 2.9% improvement based on reliability in recognition rate.

Comparison of Distance of Subacromial Space Using Ultrasonographic Measurement on Arm Positions of Shoulder Injured Patients (견부손상환자의 팔의 자세에 따른 초음파 영상을 이용한 견봉하공간 거리의 비교)

  • Jee, Eun-Mi;Kim, Suhn-Yeop;Park, Ji-Whan
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.4
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    • pp.397-406
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    • 2011
  • Purpose : Recently ultrasound images has been used to measure the subacromial space with a linear measurement of the acromiohumeral distance. The purpose of this study was to comparison of distance of subacromial space using ultrasonographic measurement on arm positions of shoulder injured patients. Methods : The subjects were 30 shoulder injured patients (19 males and 11 females). Ultrasonography was performed to measure subacromial space during each shoulder resting position, $45^{\circ}$ abduction, internal rotation with $45^{\circ}$ abduction and external rotation with $45^{\circ}$ abduction. Results : Subacromial space was a significantly difference between injured arm and normal arm at shoulder resting position. At $45^{\circ}$ abduction, subacromial space was narrowing significantly between injured arm and normal arm. At external rotation with $45^{\circ}$ abduction, subacromial space were wider in normal arm than in injured arm but it was not significantly. Intra-observer reliability for ultrasonography measurement of subacromial distance was excellent (.96~.99). Conclusion : These results identified that positions of injured shoulder was related to subacromion space.

A Study on the Object Angle Inference in a Sonar Sensor Array System (초음파센서 배열 시스템에서 물체의 각도 추론에 관한 연구)

  • 나승유;박민상
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.271-274
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    • 1998
  • Ultrasonic sensors are becoming indispensable components in every sector of automation equipments due to many advantages. But the main purposes of the noncontact sensing device are rather narrowly confined within object detection and distance measurement. To widen the realm of the applications to object recognition, ultrasonic sensors need to improve the recognition resolution to a certain amount. To resolve the problem of spatial resolution restriction, an increased number of the sensors in the forms of a linear array or 2-dimensional array of the sensor has been used. Also better resolution has been obtained by shifting the array in several steps using mechanical actuators. For an object recognition using ultrasonic sensors, measurements of distance, shift, oblique angle in certain ranges should be obtained. But a little attention has been paid to the measurement of angles. In this paper we propose a practical method for an object angular value detection in addition to distance measurement in ultrasonic sensor array system with little additional hardware burden. Using the established measurement look-up table for the variations of distance, shift, angle and transmitter voltages for each sensor characteristics, a set of different return echo signals for adjacent receivers are processed to provide enhanced angular value reading for an object.

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