• Title/Summary/Keyword: Displacement

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A Study of Micro Displacement Measurement of Micro System using the Laser Interferometer (레이저 간섭계를 이용한 마이크로 시스템의 미소변위 측정에 관한 연구)

  • Choi, Kyung-Hyun;Kim, Chang-Jong;Cho, Su-Jeong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.5 no.2
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    • pp.22-26
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    • 2006
  • This paper addresses the development of a laser interferometer to measure micro displacement for a micro system. The laser interferometer is able to measure micro displacement during a few micro seconds with non-contact. In order to employ the interferometer, the displacement calibration experiment should be required. For the experiment, a laser probe installed on the optical table with optical devices and a micro stage. The velocity decoding board is also added to calculate doppler shift frequency directly. The output signal is processed by LabView. Finally experiments are found out the relation between displacement and output signal.

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Displacement Measuring Method using Terrestrial LiDAR for Safety and Serviceability Monitoring of Steel Beams (지상 LiDAR를 이용한 철골보의 안전 및 사용성 모니터링을 위한 변위 계측기법)

  • Lee Hong-Min;Park Hyo-Seon;Lee Im-Pyeong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.190-197
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    • 2005
  • To monitor the safety and serviceability of a structures, structural responses including displacements due to various design and unexpected loadings must be measured. The maximum displacement and its distributions of a structure can be used as a direct assessment index on its stiffness. For this reason, there have been diversely studied on measuring of the maximum displacement of a structure. However, there is no practical method for measuring displacement of a structure. Therefore, in this paper, new displacement measuring method is developed and accuracy of LiDAR is examined in detail for development of a new method for measuring displacement of a structure.

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Force per unit Displacement according to the Shape of a Clasp Arm and Flexibility of the Material (Clasp arm의 형상과 재료 탄성에 따른 단위 변위에 대한 힘)

  • Lim, Dong-Chun
    • Journal of Technologic Dentistry
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    • v.23 no.2
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    • pp.171-177
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    • 2002
  • The purpose of this study is to evaluate force per unit displacements according to the shape of a clasp arm and flexibility of the material. Effect of four shape parameters of a clasp, base width and thickness and tip width and thickness, on tip displacement and force per unit displacement was investigated to get the fact that displacement and force per unit displacement at the tip increase as thickness and width of clasp arm increase just as expected. But force per unit displacement is much more affected by the change in thickness than by change in width. So it is effective to increase the thickness rather than width in order to increase the force at the tip using the same amount of the material.

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A Study on Stability for Traverse Cam of Twising Machine using Shape Design Method of Relative Velocity and Modified Displacement Curves (상대속도에 의한 형상설계법과 개선된 변위선도에 의한 연사기용 Traverse Cam의 안정성에 관한 연구)

  • Kim, Jong-Su;Yun, Ho-Eop
    • 연구논문집
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    • pp.101-112
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    • 2001
  • A Twisting machine is to twist yarns for improving yarn stiffness. After twisting yarns, the twisting machine is winding yarn at a bobbin. Traverse cam is main part of winding yarn part. In other to improve twisting machine performance and stability, improve traverse cam part. Original displacement curves of traverse cam has two problems. One is that displacement curve has a vertex point the other is that velocity curve is discontinue point. So that, in this paper proposes a modified displacement curves of traverse cam and new shape design method of the traverse cam using the relative velocity method[1]. The relative velocity method calculates the relative velocity of the follower versus the cam at a center of roller, and then determines a contact point by using the geometric relationship and the kinematical constraints. Finally, we present to compare two designed cam. One is designed using original displacement curves the other is using modified displacement curve.

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A STUDY ON DIFFERENT AMOUNT OF DENTURE BASE DISPLACEMENT USING SOFT DENTURE RELINING MATERIAL UNDER MASTICATORY FORCE (국소의치상을 위한 연성 이장재사용시 교합압에 따른 의치상 변위(Displacement)량 비교)

  • Lee, Ho-Yong
    • The Journal of Korean Academy of Prosthodontics
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    • v.36 no.1
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    • pp.18-25
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    • 1998
  • The purpose of this study was to determine how to use soft relining material by observing an amount of denture displacement according to the different base area of residual ridge and thickness of soft relining material under masticatory force. Stone models that simulated residual ridge were made with different amount of denture base area and denture was fabricated by conventional heat curing resin with usual manner on the model and relined by silicone type soft relining material with different thickness. Specimen was examined the amount of denture displacement by Instron within range of normal occlusal force. The results were as following : 1. The increasing rate of denture displacement was higher than that of soft relining material thickness. 2. The amount of denture displacement decreased 1.7 times when base area became double at same thickness of soft relining material 3. The increasing rate of denture displacement was higher than that of occlusal force

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Enhanced Strain Imaging Using Quality Measure

  • Jeong, Mok-Kun;Kwon, Sung-Jae
    • The Journal of the Acoustical Society of Korea
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    • v.27 no.3E
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    • pp.84-94
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    • 2008
  • Displacement estimation is a crucial step in ultrasonic strain imaging. The displacement between a pre- and postcompression signal in the current data window is estimated by first shifting the postcompression signal by the displacement obtained in the previous data window to reduce their decorrelation and then determining the remaining part of the displacement through autocorrelation and conversion of phase difference into time delay. However, since strain image quality tends to vary with the amount of compression applied, we propose two new methods for enhancing strain image quality, i.e., displacement normalization and adaptive persistence. Both in vitro and in vivo experiments are carried out to acquire ultrasound data and produce strain images in real time under the application of quasi static compression. The experimental results demonstrate that the methods are quite effective in improving strain image quality and thus can be applied to implementing an ultrasound elasticity imaging system that operates in real time.

A Study on the Displacement Measuring Method of High-rise Buildingas using LiDAR (라이다를 이용한 고층 건물의 변위 계측 기법에 관한 연구)

  • Lee Hong-Min;Park Hyo-Seon
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.151-158
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    • 2006
  • Structural health monitoring is concerned with the safety and serviceability of the users of structures, especially for the case of building structures and infrastructures. When considering the safety of a structure, the maximum stress in a member due to live load, earthquake, wind, or other unexpected loadings must be checked not to exceed the stress specified in a code. It will not fail at yield, excessively large displacements will deteriorate the serviceability of a structure. To guarantee the safety and serviceability of structures, the maximum displacement in a structures must be monitored because actual displacement is a direct assessment index on its stiffness. However, no practical method has been reported to monitor the displacement, especially for the case of displacement of high-rise buildings because of not to easy accessive. In this paper, it is studied displacement measuring method of high-rise buildings using LiDAR The method is evaluated by analyzing accuracy of measured displacements for existing building.

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The Tip Position Measurement of a Flexible Robot Arm Using a Vision Sensor (비전 센서를 이용한 유연한 로봇팔의 끝점 위치 측정)

  • Shin, Hyo-Pil;Lee, Jong-Kwang;Kang, E-Sok
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.8
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    • pp.682-688
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    • 2000
  • To improve the performance of a flexible robot arm one of the important things is the vibration displacement measurement of a flexible arm. Many types of sensors have been used to measure it, The most popular has been strain gauges which measures the deflection of the beam,. Photo sensors have also been for detecting beam displacement and accelerometers are often used to measure the beam vibration. But the vibration displacement can be obtained indirectly from these sensors. In this article a vision sensor is used as a displacement sensor to measure the vibration displacement of a flexible robot arm. Several schemes are proposed to reduce the image processing time and increase its accuracy. From the experimental results it is seen that the vision sensor can be an alternative sensor for measuring the vibration displacement and has a potential for on-line tip position control of flexible robot systems.

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Multi-Degree-of-Freedom Displacement Measurement of a Rigid Body Using a Diffraction Grating as a Cooperative Target (회절 격자 표식을 이용한 강체의 다자유도 변위 측정)

  • Kim, Jong-Ahn;Bae, Eui-Won;Kim, Kyung-Chan;Kim, Soo-Hyun;Kwak, Yoon-Keun
    • Proceedings of the KSME Conference
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    • pp.415-419
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    • 2000
  • Multi-degree-of-freedom (MDOF) displacement measurement Is needed In many application fields: precision machine control, precision assembly, vibration analysis, and so on. This paper presents a new MDOF displacement measurement method using a laser diode (LD), two position-sensitive detectors (PSDs), and a conventional diffraction grating. It utilizes typical features of a diffraction grating to obtain the information of MDOF displacement. MDOF displacement is calculated from the independent coordinate values of the diffracted ray spots on the PSDs. Forward and inverse kinematic problems were solved to compute the MDOF displacement of a rigid body. Experimental results show maximum absolute errors of less than ${\pm}10$ micrometers in translation and ${\pm}30$ arcsecs in rotation.

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Case Study of Estimate the Response Displacement for the Seismic Design of Shaft Cable Tunnel (수직전력구 내진설계를 위한 응답변위 산정에 대한 사례 조사)

  • Kim, Yong-Min;Jeong, Sang-Seom;Kim, Young-Ho;Kwon, Young-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.634-639
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    • 2009
  • The response displacement method is the most frequently used method for the seismic design of underground structures. Underground structures under seismic loading will tend to deform with the surrounding ground, and thus the structure is designed to accommodate the free-field deformation without loss of its structural integrity. This method is pseudo-static method, and response displacement of surrounding ground are most important steps. In this study, the single cosine method and the equivalent linear analysis are applied to estimate the response displacement of the real sites, and the results of the each method are compared. Response analysis was also performed with respect to bedrock depth. As a results, Equivalent linear analysis result was larger than single cosine method. And, the relative displacement becomes lager according to depth of the bedrock.

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