• Title/Summary/Keyword: Measurement point

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Measuring System for Impact Point of Arrow using Mamdani Fuzzy Inference System (Mamdani 퍼지추론을 이용한 화살의 탄착점 측정 시스템)

  • Yu, Jung-Won;Lee, Han-Soo;Jeong, Yeong-Sang;Kim, Sung-Shin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.4
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    • pp.521-526
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    • 2012
  • The performance of arrow from a manufacturing process depends on arrow's trajectory(archer's paradox) and intensity of an impact points. Especially, when conducting a shooting experiment over and over in the same experiment condition, the intensity of impact point is an objective standard to judge the performance of the arrow. However, the analysis method for the impact point is not enough, a previous research of the arrow's performance has been focused on a skill to optimize a manufacturing variables(feathers of an arrow, barb of an arrow, arrow's shaft, weight, external diameter, spine). In this paper, We propose measurement system of arrow's impact point with Mamdani fuzzy inference system and similarity of polygon for automation of impact point's measurement. Measuring the impact point data of the arrow moving with a high speed(approximately 275km/h) by using line laser and photo diode array, then the measured data are mapped to arrow's impact point with fuzzy inference and similarity of polygon.

Measurement System of Dynamic Liquid Motion using a Laser Doppler Vibrometer and Galvanometer Scanner (액체거동의 비접촉 다점측정을 위한 레이저진동계와 갈바노미터스캐너 계측시스템)

  • Kim, Junhee;Shin, Yoon-Soo;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.5
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    • pp.227-234
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    • 2018
  • Researches regarding measurement and control of the dynamic behavior of liquid such as sloshing have been actively on undertaken in various engineering fields. Liquid vibration is being measured in the study of tuned liquid dampers(TLDs), which attenuates wind motion of buildings even in building structures. To overcome the limitations of existing wave height measurement sensors, a method of measuring liquid vibration in a TLD using a laser Doppler vibrometer(LDV) and galvanometer scanner is proposed in this paper: the principle of measuring speed and displacement is discussed; a system of multi-point measurement with a single point of LDV according to the operating principles of the galvanometer scanner is established. 4-point liquid vibration on the TLD is measured, and the time domain data of each point is compared with the conventional video sensing data. It was confirmed that the waveform is transformed into the traveling wave and the standing wave. In addition, the data with measurement delay are cross-correlated to perform singular value decomposition. The natural frequencies and mode shapes are compared using theoretical and video sensing results.

Measurement of Fire Point and Flash Point for Alcohols Using Tag Open-Cup Apparatus (Tag식 개방계 장치를 이용한 알콜류의 인화점 및 연소점 측정)

  • Ha Dong-Myeong;Lee Sung-Jin;Song Young-Ho
    • Journal of the Korean Society of Safety
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    • v.19 no.4 s.68
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    • pp.69-73
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    • 2004
  • The flash point is one of the most important combustible properties used to determine the potential for the fire and explosion hazards of industrial material and the fire point is the temperature of the flammable liquid at which there will be flaming combustion, sustained 5 seconds in response to the pilot flame. In this study, the flash point and fire point were measured to present raw data of the flammable risk assessment for alcohols, using Tag open-cup apparatus(ASTM D 1310-86). The measured values were compared with the calculated values based on 0.78 times stoichiometric concentration. The values calculated by the proposed equations were in good agreement with the measured values.

Extraction of Geometric Primitives from Point Cloud Data

  • Kim, Sung-Il;Ahn, Sung-Joon
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2010-2014
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    • 2005
  • Object detection and parameter estimation in point cloud data is a relevant subject to robotics, reverse engineering, computer vision, and sport mechanics. In this paper a software is presented for fully-automatic object detection and parameter estimation in unordered, incomplete and error-contaminated point cloud with a large number of data points. The software consists of three algorithmic modules each for object identification, point segmentation, and model fitting. The newly developed algorithms for orthogonal distance fitting (ODF) play a fundamental role in each of the three modules. The ODF algorithms estimate the model parameters by minimizing the square sum of the shortest distances between the model feature and the measurement points. Curvature analysis of the local quadric surfaces fitted to small patches of point cloud provides the necessary seed information for automatic model selection, point segmentation, and model fitting. The performance of the software on a variety of point cloud data will be demonstrated live.

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Error-compensating Techniques in 3-Point Weighing Method to Measure Unbalance Properties (3점 방식 불평형량 측정법에서의 오차보상 기법)

  • Lee, Sun-Pyo
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.11 s.188
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    • pp.42-49
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    • 2006
  • In this paper error-compensating techniques in three-point weighing method to precisely measure unbalance properties such as center of gravity and unbalance moment. In the conventional static methods, 1) fixture-errors, 2) effects of the contact between the fixture and the load scales, and 3) side effect due to the lateral frictional forces acting on the contact points between the fixture and the load scales are the major factors that lead to measurement errors. The proposed error-compensating method perfectly eliminates both the fixture-error and the contact-error simultaneously by manipulating the three measured reaction forces at three different angular locations. Also the friction-error is calibrated by comparing the sum of three reactions with the actual mass of the specimen. A set of measurement is performed using the same measuring system as Lee's, and a comparison of the results from the convectional, Lee's, and the proposed method is provided. The results show that the proposed method effectively compensates the errors listed above.

Development of Non-contact Image Measuring Technique for Evaluating Micro-relief (미세주름 측정을 위한 비접촉식 영상측정기술의 발전)

  • Kim, Nam-Soo;Kim, Yong-Min
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.31 no.3 s.52
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    • pp.253-257
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    • 2005
  • Assurance of the objectivity and reproducibility is a major key point in wrinkle measurement used for evaluating the degree of skin aging. The measurement of relief is quickly converted to a non-contact method, of which tools or instruments do not come in contact with skin directly, to minimize the artificial effects which influence the shape or depth of the relief. Here, we showed how wrinkle measurement techniques have been changed briefly and compared PRIMOS and replica method in the point of view of measurement principle and features, the former is non-contact fringe projection tool and the latter is contact type of the method.

A study of measurement of the unknown load impedance using sectioned transmission line (${\lambda}/4$ 전송선로를 이용한 부하단 임피던스 측정방법에 관한 연구)

  • Hwang, Soo-Sul;Hong, Sung-Yong
    • Journal of Satellite, Information and Communications
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    • v.6 no.2
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    • pp.91-96
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    • 2011
  • In this paper, we present measurement method of the unknown load impedance. Load impedance is continuously varied by external environment conditions. This arbitrarily varied load impedance can be calculated using 3-point voltage measurement on ${\lambda}/4$ sectioned transmission line. We derived several numerical formulas from 3-point voltage measurement results and drew load impedance selection algorithm from calculated load impedance results. These numerical formulas and load impedance selection algorithm are verified by ADS simulation. Simulation results showed that arbitrary load impedance can be correctly measured using above mentioned formulas and selection algorithm.