• Title/Summary/Keyword: Distance measurement

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Unrestricted Measurement Method of Three-dimensional Walking Distance Utilizing Body Acceleration and Terrestrial Magnetism

  • Inooka, Hikaru;Kim, HiSik
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.94.5-94
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    • 2001
  • Unrestricted measurement method of three-dimensional walking distance utilizing body acceleration and terrestrial magnetism is discussed. The three-dimensional walking distance is derived by the integration of the three dimensional acceleration of foot during swing phase. Since the sensor system attached on the foot rotates during swing phase, the acceleration data measured on the foot include acceleration of gravity which causes inaccurate calculation of the velocity and the distance. Three gyros are used to compensate the rotation of the sensor system. Moreover, one geomagnetic sensor is employed to derive the heading direction of the subject Healthy volunteers performed ...

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Nerve length measurement method in a radial motor nerve conduction study

  • Kim, Jae-Gyum;Kim, Yoohwan;Seok, Hung Youl;Kim, Byung-Jo
    • Annals of Clinical Neurophysiology
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    • v.19 no.1
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    • pp.28-33
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    • 2017
  • Background: Previous studies of radial nerve conduction study (NCS) did not present how to measure the length of the radial nerve across the elbow, and did not even mention how to manage the spiral course of the nerve. This study aimed to applicate the most reliable method to measure the length of the radial nerve during NCS. Methods: Three points (A, B, and C) were determined along the relatively straight course of the radial nerve. The distance was measured using three different methods: L1) straight distance corresponding to the A-C distance, L2) sum of the distances corresponding to the A-B-C distance, L3) based on the L2, but the elbow is flexed at a $45^{\circ}$ angle. We compared the three methods of distance measurement and the calculated nerve conduction velocities (V1, V2, and V3) in normal healthy subjects. Results: 19 normal participants were enrolled. The mean value for method L1, L2 and L3 were $22.5{\pm}1.8cm$, $24.0{\pm}2.1cm$, and $23.2{\pm}2.1cm$ (p < 0.001). Calculated conduction velocities using those distance measurement methods as follows (p < 0.001): V1 ($60.9{\pm}2.7m/s$), V2 ($64.6{\pm}3.3m/s$), and V3 ($63.4{\pm}3.9m/s$). V2 was significantly greater than V1 and V3 (p < 0.001, p = 0.010, respectively). Conclusions: The distance measurement using a stopover point near the lateral epicondyle between two stimulus points in position of a fully extended elbow with forearm pronation is the most appropriate posture for radial motor NCS.

A Distance Measurement System Using a Laser Pointer and a Monocular Vision Sensor (레이저포인터와 단일카메라를 이용한 거리측정 시스템)

  • Jeon, Yeongsan;Park, Jungkeun;Kang, Taesam;Lee, Jeong-Oog
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.5
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    • pp.422-428
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    • 2013
  • Recently, many unmanned aerial vehicle (UAV) studies have focused on small UAVs, because they are cost effective and suitable in dangerous indoor environments where human entry is limited. Map building through distance measurement is a key technology for the autonomous flight of small UAVs. In many researches for unmanned systems, distance could be measured by using laser range finders or stereo vision sensors. Even though a laser range finder provides accurate distance measurements, it has a disadvantage of high cost. Calculating the distance using a stereo vision sensor is straightforward. However, the sensor is large and heavy, which is not suitable for small UAVs with limited payload. This paper suggests a low-cost distance measurement system using a laser pointer and a monocular vision sensor. A method to measure distance using the suggested system is explained and some experiments on map building are conducted with these distance measurements. The experimental results are compared to the actual data and the reliability of the suggested system is verified.

A Study on the Moving Distance Measurement System using a Accelerometer Sensor (가속도 센서를 이용한 이동거리 측정 시스템 연구)

  • Park, Seung-Hun;Kim, Sung-Woo;Lim, Jae-Hwan;Ryu, Jee-Youl
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.283-285
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    • 2012
  • In this research, we produced a simple momentum measurement system which figures out information for the real-time travel distance with modularizing a momentum measurement system by using the acceleration sensor, MCU and Bluetooth to measure the exact momentum. In the simulation experiments, we compared the reliability and accuracy of the new momentum measurement system with those of existing momentum measurement systems to confirm that the new momentum measurement system shows superior reliability and accuracy. Base on this results, we will produce the enhanced momentum measurement system, compact and possible to shoe-mount, in future.

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Parallelism Measurement of Rolls by Using a Laser Interferometer (레이저 간섭계를 이용한 롤 평행도 측정 기술)

  • Choi, Jong Geun;Kim, Seongeun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.6
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    • pp.642-646
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    • 2014
  • This research describes the measurement of roll parallelism by a laser interferometer. Parallelism among rolls is an important factor for improving the precision of printing devices. A laser interferometer, which is a device for the precise measurement of distance, can be utilized to measure parallelisms between rolls. To measure distance between two rolls by using a laser interferometer, the laser must not be severed during measurement. To achieve this condition, a linear motion guide was installed to each roll being measured, and continuous measurement of distance between two rolls was implemented by the simultaneous control of two mirrors installed on the guides. The method to measure parallelism between two rolls presented in this research can be utilized to improve printing precision by enhancing parallelism between rolls in printing devices.

Study on Distance Measurement of Beacon Using Extended Kalman Filter (확장 칼만 필터를 이용한 비콘의 거리 측정에 관한 연구)

  • Jang, Gyuho
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.18 no.3
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    • pp.1-7
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    • 2022
  • In this study, inaccurate RSSI values of beacons are corrected using extended Kalman filter. For the experiment, the beacon was manufactured using Arduino Uno board and HM-10 Bluetooth module. RSSI values according to the distance between beacon and the viewer were measured at intervals of 1m, 1.5m, 2m, 2.5m, 3m, 3.5m, 4m, 4.5m, and 5m. To remove the irregular signal pattern of the beacon, the extended Kalman filter was applied to obtain the average and standard deviation of the actual distance and the measured distance, and it was confirmed that more than 76.6% of the irregular signal pattern was removed after using the extended Kalman filter.In addition, through the smartphone app, it was confirmed that the distance accuracy between the beacon and the measurer was less than the actual distance and the measured distance within 2m, and the standard deviation was small.

Study on the Development of Sensors for Distance Measure Using Ultrasonic (초음파 이용 거리측정을 위한 센서 개발에 관한 연구)

  • Park, Geun Chul;Lee, Seung Hee;Park, Chang Soo;Kim, Dong Won;Kim, Won Taek;Jeon, Gye Rok
    • Journal of Sensor Science and Technology
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    • v.23 no.1
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    • pp.46-50
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    • 2014
  • In this paper, we report a novel algorithm based on phase displacement, which supplements conventional TOF methods for distance measurement using an ultrasonic wave. The proposed algorithm roughly measures the distance between the transmission part and the receiving part by using the initial TOF. Thereafter, the precise distance is determined by measuring the phase displacement value between the synchronizing transmission signal and the signal obtained at the receiving end. A distance measurement experiment using a micrometer was performed to verify the accuracy of the ultrasonic wave sensor system. We found that the mean errors from the one adopting the distance measurement algorithm based on phase displacement varied from a minimum of 0.03 mm to a maximum of 0.09 mm. In addition, the standard deviation varied from a minimum of 0.04 mm to a maximum of 0.07 mm, thus giving a precision of ${\pm}0.1$ mm.

Precision Improvement Technique of Propagation Delay Distance Measurement Using IEEE 1588 PTP (IEEE 1588 PTP를 이용한 전파 지연 거리 측정의 정밀도 향상 기법)

  • Gu, Young Mo;Boo, Jung-il;Ha, Jeong-wan;Kim, Bokki
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.6
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    • pp.515-519
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    • 2021
  • IEEE 1588 PTP is a precision time protocol in which two systems synchronize without the aid of GPS by exchanging packets including transmission/reception time information. In the time synchronization process, the propagation delay time can be calculated and the distance between the two systems can be measured using this. In this paper, we proposed a method to improve the distance measurement precision less than the modulation symbol period using the timing error information extracted from the preamble of the received packet. Computer simulations show that the distance measurement precision is proportional to the length of the preamble PN sequence and the signal-to-noise ratio.

Comparative Study on Similarity Measurement Methods in CBR Cost Estimation

  • Ahn, Joseph;Park, Moonseo;Lee, Hyun-Soo;Ahn, Sung Jin;Ji, Sae-Hyun;Kim, Sooyoung;Song, Kwonsik;Lee, Jeong Hoon
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.597-598
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    • 2015
  • In order to improve the reliability of cost estimation results using CBR, there has been a continuous issue on similarity measurement to accurately compute the distance among attributes and cases to retrieve the most similar singular or plural cases. However, these existing similarity measures have limitations in taking the covariance among attributes into consideration and reflecting the effects of covariance in computation of distances among attributes. To deal with this challenging issue, this research examines the weighted Mahalanobis distance based similarity measure applied to CBR cost estimation and carries out the comparative study on the existing distance measurement methods of CBR. To validate the suggest CBR cost model, leave-one-out cross validation (LOOCV) using two different sets of simulation data are carried out. Consequently, this research is expected to provide an analysis of covariance effects in similarity measurement and a basis for further research on the fundamentals of case retrieval.

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Development of robot work measurement by the unit motion model (단위 동작 모형에 따른 로봇 작업시간 측정법의 개발)

  • 권규식
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.367-370
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    • 1996
  • This study deals with the motion modeling by the unit motion of robots and the work measurement through classification of robot motions and standardization. The proposed approach is to scrutinize the Predetermined Time Standards(PTS) methods for measurement of manual tasks performed by people and the basic motions for accomplishing that tasks. And then, it constructs the unit motion models as subsets composed with the basic motions. It apply together with movements distance as a time variable, too. These results are used for the work measurements of robots by the unit motion models.

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