• Title/Summary/Keyword: Distance measurement

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The Measurement of Firing Noise of K2 Rifle at Close Distance (근접 측정에 의한 K2 소총 사격음의 측정)

  • 이윤
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.11
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    • pp.1123-1128
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    • 2004
  • An experimental study on firing noise of K2 rifle was performed. Firing noises of K2 rifle were measured at close distance to rifle. Firing noise of K2 rifle which made in Korea, has not measured before. The measurement of firing noise at close distance is not simple, because the amplitude of firing noise is much bigger than the measuring limit of ordinary sound level meter even though it uses a signal attenuator. The measurement of firing noise at close distance is necessary for noise source positioning and for obtaining the sound power of K2 rifle. By this experimental study, the firing noise levels of K2 rifle at different positions are obtained and these data can be used to Predict the sound pressure level at any distance from muzzle of the rifle. Also these data can be used to calculate the threshold shift of gunner's ear.

A Study on LED Distance Recognition Measure Using Distance Measurement Correction Algorithm (거리계산 보정 알고리즘을 이용한 LED 거리 인식 측정에 관한 연구)

  • Kim, Ji-Seong;Jung, Dae-Chul;Kim, Yong-Kab
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.2
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    • pp.63-68
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    • 2017
  • In this paper, Distance recognition measurement using distance calculation correction algorithm, was realization through LED dimming control. The calculation values for the RSSI average filtering and the RSSI feedback filtering were calculated and applied to reduce the error of the RSSI value measured from a long distance. It was confirmed that the RSSI values through the average filtering and the RSSI values measured by setting the coefficient value of the feedback filtering to 0.5 were ranged from -61 dBm to - 52.5 dBm, which shows irregular and high values decrease slightly as much as about -2 dBm to -6 dBm as compared to general measurements. A distance calculation correction algorithm to improve the accuracy was applied, which confirmed that as the distance increases, the range of errors decreases. In conclusion, unstable signals were corrected using the RSSI measurement result filtering, and the distance calculation correction algorithm was applied and performed to reduce the range of errors. In addition, RGB colors were implemented by LED to indicate the distance determination and the signal stability.

Quantity Measurement by CAFFE Model and Distance and Width Measurement by Stereo Vision (CAFFE 모델을 이용한 수량 측정 및 스테레오 비전을 이용한 거리 및 너비측정)

  • Kim, Won-Seob;Kim, Eung-Kon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.4
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    • pp.679-684
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    • 2019
  • We propose a method to measure the number of specific species of class using CAFFE model and a method to measure length and width of object using stereo vision. To obtain the width of an object, the location coordinates of objects appearing on the left and right sensor is compared and the distance from the sensor to the object is obtained. Then the length of the object in the image by using the distance and the approximate value of the actual length of the object is calculated.

Development of Robust Single Ultrasonic Module for Distance Measurement of Mobile Robot (이동로봇의 거리측정을 위한 고성능 일체형 초음파 모듈 개발)

  • Choi, Jong-Hoon;Shim, Hyeon-Min;Ryu, Je-Goon;Lee, Eung-Hyuk
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.418-420
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    • 2005
  • This paper proposed ultrasonic distance measurement module development for correct distance detection with collision escaping or obstacle of mobile robot is traveling self-regulation. Representative ultrasonic module applied in existing was Polaroid company's 6500 series and Devantech company's SRF04/SRF08 series. This ultrasonic sensors are corrupted by systematic errors due mainly to the dependency of sound speed upon surrounding conditions and random errors of uncertain origin. Therefore Ultrasonic distance detecting means of error compensation method and high definition, narrow beam angle, board area distance detecting means to apply to ultrasonic mobile robot control urgently need. In this paper use internal type temperature compensation method to improve problem of ultrasonic distance measurement method instead of that volume that have shortcoming of used correct temperature compensation methods applied big addition device. Compensate error by environment change of temperature. Humidity density etc. and is applicable to mobile robot offering various interface and real-time processing developed possible distance measurement module.

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Development of Measurement System of Moving Distance Using a Low-Cost Accelerometer

  • Cho, Seong-Yun;Kim, Jin-Ho;Park, Chan-Gook
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.130.4-130
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    • 2001
  • In this paper, a measurement system of moving distance is developed. The error compensation method is also proposed using the characteristics of walking motion. As personal navigation systems and multimedia systems are emerging into the commericial market, men´s moving distance is considered as one of the important information. GPS offers the information easily but GPS can be used only when the satellites are visible. INS can calculate the moving distance anywhere but error is increased with time due to the sensor bias. In this paper, to detect the human walking distance a measurement system of moving distance only using low-cost accelerometer is developed. The sensor bias is estimated and compensated using the walking motion characteristics. The performanced of the proposed system is verified by experiment.

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Analysis of far & near distance of lateral phoria by various testing methods (검사 방법에 따른 원·근거리 수평사위의 분석)

  • Hong, Dong-Gyun;Jung, Han-Sub;Park, Sang-An
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.423-430
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    • 2004
  • This Study on three different methods which are Von Graefe test, Maddox Rod test and Howell card test of measuring far and near lateral phoria investigated. It reviewed that 420 subjects aged from 15 to 35 years old. The result were as follows; 1. Using Von Graefe lateral phoria measurement, they were measured 6% for orthophoria, 62% for exophoria, 32% for esophoria at far distance. 2. Using Von Graefe lateral phoria measurement, they were measured 2% for orthophoria, 74% for exophoria, 24% for esophoria at near distance. 3. Using Maddox Rod lateral phoria measurement, they 59% for exophoria, 37% for esophoria at far distance. 4. Using Maddox Rod lateral phoria measurement, they 67% for exophoria, 30% for esophoria at near distance. 5. Using Howell card lateral phoria measurement, they 60% for exophoria, 32% for esophoria at far distance. 6. Using Howell card lateral phoria measurement, they 69% for exophoria, 27% for esophoria at near distance.

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Verification of Long-distance Vision-based Displacement Measurement System (장거리 영상기반 변위계측 시스템 검증)

  • Kim, Hong-Jin;Heo, Suk-Jae;Shin, Seung-Hoon
    • Journal of the Regional Association of Architectural Institute of Korea
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    • v.20 no.6
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    • pp.47-54
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    • 2018
  • The purpose of this study is to verify the long - range measurement performance for practical field application of VDMS. The reliability of the VDMS was verified by comparison with the existing monitoring sensor, GPS, Accelerometer and LDS. It showed the ability to accurately measure the dynamic displacement by tracking a motion of free vibration of target. And using the PSD function of measured data, the results in the frequency domain were also analyzed. We judged that VDMS is able to identify the higher system mode and has sufficient reliability. Based on the reliability verification, we conducted tests for long-distance applicability for actual application of VDMS. The distance from the stationary target model structure was increased by 50m interval, and the maximum distance was set to 400m. From the distance of 150m, the image obtained by the commercial camcorder has an error in the analysis, so the measured displacement comparison was performed between the LDS and the refractor telescope measurement results. In the measurement results of the displacement area of VDMS, the data validity was deteriorated due to the data shift by the external force and the quality degradation of the enlarged image. However, even under the condition that the effectiveness of the displacement measurement data of VDMS is low, the first mode characteristic included in the free vibration of the object is clearly measured. If the influence from the external environment is controlled and stable data is collected, It is judged that reliability of long-distance VDMS can be secured.

A Reliability Study of Tape and Photography Measurement Techniques for Scapular Position (줄자 및 사진촬영 측정을 이용한 어깨뼈 벌림 측정에 대한 신뢰도 연구)

  • Kim, Moon-Hwan;Yun, Sung-Joon;Ha, Sung-Min
    • Physical Therapy Korea
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    • v.20 no.3
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    • pp.74-80
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    • 2013
  • The purpose of this study was to determine the reliability of distance measurements from the medial border of the scapula to the spinous process of the thoracic vertebrae when obtained using tape and photography measurements. The study included 20 healthy subjects (10 males, 10 females); for a total of 40 scapula measurements. The distance measurements made using tape or photography methods were conducted with the subject in a standing position. Repeated tape and photography measurements were conducted in two sessions on different days by two examiners to assess the inter-rater and intra-rater reliability of the two methods. The reliability of scapular distance measured using tape and photography methods was tested using intraclass correlation coefficients (ICC(3,1)) and the standard error of measurement (SEM). The inter-rater reliability of the tape measurement method was excellent (ICC=.77) and the intra-rater reliability was fair to good (ICC=.74). The inter-rater and intra-rater reliabilities of the photography measurement method were excellent (ICC=.76 and .76 respectively). Our results suggest that photography measurement is an objective and qualitative measurement tool for scapular distance measurements.

Phoneme Similarity Error Correction System using Bhattacharyya Distance Measurement Method (바타챠랴 거리 측정법을 이용한 음소 유사율 오류 보정 개선 시스템)

  • Ahn, Chan-Shik;Oh, Sang-Yeob
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.6
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    • pp.73-80
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    • 2010
  • Vocabulary recognition system is providing inaccurate vocabulary and similar phoneme recognition due to reduce recognition rate. It's require method of similar phoneme recognition unrecognized and efficient feature extraction process. Therefore in this paper propose phoneme likelihood error correction improvement system using based on phoneme feature Bhattacharyya distance measurement. Phoneme likelihood is monophone training data phoneme using HMM feature extraction method, similar phoneme is induced recognition able to accurate phoneme using Bhattacharyya distance measurement. They are effective recognition rate improvement. System performance comparison as a result of recognition improve represent 1.2%, 97.91% by Euclidean distance measurement and dynamic time warping(DTW) system.

Distance Measurement and Three-Dimensional Image Display using Incoherent Holography (인코히어런트 홀로그래피를 이용한 거리계측과 3차원 영상 디스플레이)

  • 김수길;황보승
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.1
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    • pp.1-7
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    • 2002
  • We derived the resolution of the modified triangular interferometer and described the analysis about distance measurement using the one. Also, to demonstrate the feasibility of distance measurement using the modified triangular interferometer, the incoherent hologram of a two-point source with depth and its numerical reconstruction were presented. We demonstrated the possibility of the modified triangular interferometer as a three-dimensional display by recording and reconstructing the incoherent hologram of three-dimensional image.