• Title/Summary/Keyword: Moving distance

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Influence of Two Moving Masses on Dynamic Behavior of a Simple Beam (두 이동질량이 단순보의 동특성에 미치는 영향)

  • Yoon, H.I.;Choi, C.S.;Im, S.H.
    • Journal of Power System Engineering
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    • v.4 no.4
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    • pp.70-77
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    • 2000
  • On the dynamic behavior of a simple beam the influences of the velocities and distance of two moving masses have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving masses represented by the time functions. As increasing the velocties of two moving masses on the simple beam, the amplitude of the transverse vibration of the simple beam is decreased and the frequency of the transverse vibration of the simple beam is increased. As the distance between two moving masses increase, the transverse displacement of the simple beam is decrease. The simple beam is very stable in second mode at $\bar{a}=0.5$ and in third mode at $\bar{a}=0.3$.

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A Study on the Distance Error Correction of Maritime Object Detection System (해상물체탐지시스템 거리오차 보정에 관한 연구)

  • Byung-Sun Kang;Chang-Hyun Jung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.2
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    • pp.139-146
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    • 2023
  • Maritime object detection systems, which detects small maritime obstacles such as fish farm buoys and visualizes distance and direction, is equipped with a 3-axis gimbal to compensate for errors caused by hull motion, but there is a limit to distance error corrections necessitated by the vertical movement of the camera and the maritime object due to wave motions. Therefore, in this study, the distance error of maritime object detection systems caused by the movement of the water surface according to the external environment is analyzed and corrected using average filter and moving average filter. Random numbers following a Gaussian standard normal distribution were added to or subtracted from the image coordinates to reproduce the rise or fall of the buoy under irregular waves. The distance calculated according to the change of image coordinates, the predicted distance through the average filter and the moving average filter, and the actual distance measured by laser distance meter were compared. In phases 1 and 2, the error rate increased to a maximum of 98.5% due to the changes of image coordinates due to irregular waves, but the error rate decreased to 16.3% with the moving average filter. This error correction capability was better than with the average filter, but there was a limit due to failure to respond to the distance change. Therefore, it is considered that use of the moving average filter to correct the distance error of the maritime object detection system will enhance responses to the real-time distance change and greatly improve the error rate.

The Influence of Moving Masses on Dynamic Behavior of a Cantilever Pipe Subuected to Uniformly Distributed Follower Forces (이동질량과 등분포접선종동력이 외팔보의 동특성에 미치는 영향)

  • Son, In-Soo;Yoon, Han-Ik;Kim, Hyun-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.80-85
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    • 2002
  • A conveying fluid cantilever pipe system subjected to an uniformly distributed tangential follower force and three moving masses upon it constitute this vibrational system. The influences of the velocities of moving masses, the distance between two moving masses. and the uniformly distributed tangential follower force have been studied on the dynamic behavior of a cantilever pipe system by numerical mettled. The uniformly distributed tangential follower force is considered within its ciritical value of a cantilever pipe without moving masses, and three constant velocities and three constant distance between two moving masses are also chosen. When the moving masses exist on pipe, As the velocity of the moving mass and distributed tangental force increases, the deflection of cantilever pipe conveying fluid is decreased, respectively. Increasing of the velocity of fluid flow make the amplitude of cantilever pipe conveying fluid decrease. After the moving mass passed upon the pipe, the tip displacement of pipe is influenced by the potential energy of cantilever pipe.

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Design of Runner System and Prediction of Moving Distance of the Screw for the Improvement of Formability of a Housing Part of Small-Size Air Cleaner (소형 공기청정기 하우징의 성형성 향상을 위한 런너시스템 설계 및 스크류 전진 거리 예측)

  • Kim, Dong-In;Lee, Ho-Jin;Ahn, Dong-Gyu
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.12
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    • pp.1021-1030
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    • 2016
  • The runner system of the injection mould and the injection volume of the injection molding process greatly affect the quality of the produced part. The goal of this paper is the design of the runner system and the prediction of the injection volume for the injection moulding of a housing part of small-size air cleaner to improve the formability through the three-dimensional injection moulding analysis. The effects of the runner system of the mould on the injection moulding characteristics are investigated. From the results of the investigation, a proper design of the runner system with uniform filling characteristics and the minimized defect formation is obtained. In addition, the influence of the moving distance of the screw on filling characteristics, weldline formation and deformation characteristics is examined. From the results of the examination, an appropriate moving distance of the screw for the housing part of small-size air cleaner is estimated.

Upward, Downward Stair Detection Method by using Obliq ue Distance (사거리를 이용한 상향, 하향 계단 검출 방법)

  • Gu, Bongen;Lee, Haeun;Kwon, Hyeokmin;Yoo, Jihyeon;Lee, Daho;Kim, Taehoon
    • Journal of Platform Technology
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    • v.10 no.2
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    • pp.10-19
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    • 2022
  • Moving assistant devices for people who are difficult to move are becoming electric-powered and automated. These moving assistant devices are not suitable for moving stairs at which the height between floor surfaces is different because these devices are designed and manufactured for flatland moving. An electric-powered and automated moving assistant device should change direction or stop when it approaches stairs in a movement direction. If the user or automatic control system does not change direction or stop in time, a moving assistant device can roll over or collide with stairs. In this paper, we propose a stairs detection method by using oblique distance measured by one sensor tilted to flatland. The method proposed in this paper can detect upward or downward stairs by using a difference between a predicted and measured oblique distance in considering a tilted angle of a sensor for measuring an oblique distance and installation height of the sensor on a moving object. Before the device enters a stairs region, if our proposed method provides information about detected stairs to a device's controller, the controller can do adequate action to avoid the accident.

Fluid flow profile in the "orthotropic plate+compressible viscous fluid+rigid wall" system under the action of the moving load on the plate

  • Akbarov, Surkay D.;Huseynova, Tarana V.
    • Coupled systems mechanics
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    • v.9 no.3
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    • pp.289-309
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    • 2020
  • The paper studies the fluid flow profile contained between the orthotropic plate and rigid wall under the action of the moving load on the plate and main attention is focused on the fluid velocity profile in the load moving direction. It is assumed that the plate material is orthotropic one and the fluid is viscous and barotropic compressible. The plane-strain state in the plate and the plane flow of the fluid is considered. The motion of the plate is described by utilizing the exact equations of elastodynamics for anisotropic bodies, however, the flow of the fluid by utilizing the linearized Navier-Stokes equations. For the solution of the corresponding boundary value problem, the moving coordinate system associated with the moving load is introduced, after which the exponential Fourier transformation is employed with respect to the coordinate which indicates the distance of the material points from the moving load. The exact analytical expressions for the Fourier transforms of the sought values are obtained, the originals of which are determined numerically. Presented numerical results and their analyses are focused on the question of how the moving load acting on the face plane of the plate which is not in the contact with the fluid can cause the fluid flow and what type profile has this flow along the thickness direction of the strip filled by the fluid and, finally, how this profile changes ahead and behind with the distance of the moving load.

The Influence of Moving Masses on Natural Frequency of Cantilever Pipe Conveying Fluid (유체유동 외팔 파이프의 고유진동수에 미치는 이동질량들의 영향)

  • 윤한익;손인수;진종태;김현수
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.11
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    • pp.840-846
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    • 2002
  • The vibrational system of this study is consisted of a cantilever pipe conveying fluid, the moving masses upon it and an attached tip mass. The equation of motion is derived by using Lagrange equation. The influences of the velocity and the number of moving masses and the velocities of fluid flow in the pipe have been studied on the natural frequency of a cantilever pipe by numerical method. As the size and number of a moving mass increases, the natural frequency of cantilever pipe conveying fluid is decreased. When the first a moving mass Is located at the end of cantilever pipe, the increasing of the distance of moving masses make the natural frequency increase at first and third mode, but the frequency of second mode is decreased. The variation of natural frequency of the system is decreased due to increase of the number of a moving mass. The number and distance of moving masses effect more on the frequency of higher mode of vibration.

Application of Euclidean Distance Similarity for Smartphone-Based Moving Context Determination (스마트폰 기반의 이동상황 판별을 위한 유클리디안 거리유사도의 응용)

  • Jang, Young-Wan;Kim, Byeong Man;Jang, Sung Bong;Shin, Yoon Sik
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.4
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    • pp.53-63
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    • 2014
  • Moving context determination is an important issue to be resolved in a mobile computing environment. This paper presents a method for recognizing and classifying a mobile user's moving context by Euclidean distance similarity. In the proposed method, basic data are gathered using Global Positioning System (GPS) and accelerometer sensors, and by using the data, the system decides which moving situation the user is in. The decided situation is one of the four categories: stop, walking, run, and moved by a car. In order to evaluate the effectiveness and feasibility of the proposed scheme, we have implemented applications using several variations of Euclidean distance similarity on the Android system, and measured the accuracies. Experimental results show that the proposed system achieves more than 90% accuracy.

Realization for Moving Object Sensing and Path Tracking System using Stereo Line CCDs (스테레오 라인 CCD를 이용한 이동객체감지 및 경로추적 시스템 구현)

  • Ryu, Kwang-Ryol;Kim, Young-Bin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.11
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    • pp.2050-2056
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    • 2008
  • A realization for moving object sensing and tracking system in two dimensional plane using stereo line CCDs and lighting source is presented in this paper. The system is realized that instead of processing camera images directly, two line CCD sensor and input line image is used to measure two dimensional distance by comparing the brightness on line CCDs. The algorithms are used the moving object sensing, path tracking and coordinate converting method. To ensure the effective detection of moving path, a detection algorithm to evaluate the reliability of each measured distance is developed. The realized system results are that the performance of moving object recognizing shows 5mm resolution, and enables to track a moving path of object per looms period.