• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1999.03a
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• pp.17-23
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• 1999

본 논문에서는 절리면 거칠기를 정밀하게 수치화 하기 위해 레이저 변위계를 이용한 3차원 거칠기 측정기를 구동시키는 프로그램 제작 및 여러 가지 상태의 절리면에 대해 수치화를 실시하여 각종 거칠기 파라미터를 결정한 후 오차분석을 실시하여 이 기계를 이용한 측정의 타당성을 검증하였다. 동일한 절리면에 대해 물리적인 접촉에 의한 3차원 거칠기 측정기로부터 얻어진 거칠기 파라미터와 레이저 변위계를 이용한 측정기로부터 얻어진 것들 사이의 관계를 살펴보았고, 레이저 측정기에 의해 수치화된 절리면 거칠기 파라미터 사이의 상관관계를 조사하였다. 연구에 사용한 시료는 황등화강암, 여산대리석의 2종류이며, 절리형상 측정을 위한 절리는 인장균열 발생장치를 이용하여 인공적으로 제작하였다. (중략)

• Journal of the Korean Geosynthetics Society
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• v.13 no.1
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• pp.23-31
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• 2014

In this study, the method to measure effectively the ground surface displacement of slope was proposed using the Laser Distance Measurer (LDM). Applying the proposed technique is more simple and easier than the complicated and high-priced instrument to measure the ground surface displacement. LDM is an instrument that the red laser aimed at the target and then the reflected laser used for calculating the distance. The advantages of LDM are easy operating method, high measurement precision and lower in price. To check the feasibility, the proposed method applied to the real site that the ground surface displacement of slope was occurred continuously. The ground surface displacements were occurred in various points of the natural and cut slopes located at the lower part of coal mine waste heap due to the load of waste heap. To measure directly the ground surface displacement in this site, 6 measurement sections and 26 measurement points were selected. As the result of the displacement measured by the proposed technique within a certain period time, the accumulative ground surface displacement could be measured as well as the velocity of displacement could be estimated. Also, the progress direction of ground surface displacement can be confirmed and predicted through the analysis of all measured result.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.1
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• pp.12-18
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• 2008

In this research, we proposed a method for high precision measurement than laser displacement measurement. The proposed method finds the causes of error due to change in reflected laser signal level reflected from an object and compensation, and we designed this by applying laser displacement meter.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.187-193
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• 2009

A lens which is one of cores for the high precision laser range finder is utilized to compute the distance by measuring the phase displacement. In order to measure the phase displacement, we transmit the optical signal from the laser diode to a target and receive the reflected laser light from the target. In this paper, we propose new lens design technique to solve the problem due to the inconsistent curvature of the lens, which consistently collects optical signals and performs the transmission and reception of the optical data, and test the implementation of the laser range finder based on the proposed technique. Since the proposed laser range finder has low error rate comparing to the conventional techniques, it may be apply to the high precision distance measurement.

• Tunnel and Underground Space
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• v.12 no.4
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• pp.268-276
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• 2002

In this study, a 3D coordinate measurement system equipped with a laser displacement meter for digitizing rock joint surface was established and the digitized data were used to calculate several roughness parameters. The parameters used in this study were micro avenge inclination $angle(i_{ave})$, average slope of joint $asperity(SL_{ ave})$, root mean square of $i-angle(i_{rms})$, standard deviation of height(SDH), standard deviation of $i-angle(SD_i)$, roughness profile $index(R_P)$, and fractal dimension(D). The relationships between the roughness parameters based on the digitzation of the surface profile were analyzed. Since the measured value varied according to the degree of reflection and the variation of colors at the measuring point, rock joint surface was painted in white to minimize the influence of the surface conditions. The comparison of the measured values and roughness parameters before and after painting revealed the better consequence from measurement on the painted surfaces. Also, effect of measuring interval was studied. As measured interval was increased, roughness parameters were exponentially decreased. The incremental sequence of degree of decrease was $SDH\; i_{ave},\; i_{rms},\; SD_i,\;and\; R_ p-1$. As a result of comparison of parameters from pin-type measurement system and laser type measurement system, all value of parameters were higher when laser-type measurement system was used, except SDH.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.415-418
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• 2005

In the semiconductor and optical industry, a new transport system which can replace the conventional transport systems is required. The transport systems are driven by the magnetic field and conveyer belts. The magnetic field may damage semiconductor and the contact force may scratch the optical lens. The ultrasonic wave driven system can solve these problems. In this semiconductor and optical industry, the non-contact system is required fur reducing the damages. The ultrasonic transportation is the solution of the problem. In this paper, the ultrasonic levitation system fur levitating object are proposed. The 3D vibration profiles of the beam are measured by Laser scanning Vibrometer fur verifying the vibration characteristics of the system and the amplitudes of the beam and the levitation heights of object are measured for evaluating the performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.959-962
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• 2005

In the semiconductor and optical industry. a new transport system which can replace the conventional transport system is required. The Transport systems are driven by the magnetic field and conveyer belts. The magnetic field may damage semiconductor and the contact force may scratch the optical lens. The ultrasonic wave driven system can solve these problems. In this semiconductor and optical industry, the non-contact system is required for reducing the damages. The ultrasonic transportation is the solution of the problem. In this paper, the ultrasonic levitation system for levitation object are proposed. The 3D vibration profiles of the beam are measured by Laser Scanning Vibrometer for verifying the vibration characteristics of the system and the amplitudes of the beam and the levitation heights of object are measured fore evaluating the performance.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.35-35
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• 2002

나노미터 표준을 확립하기 위하여 일체식 엑스선 간섭계에 광간섭계를 결합시킨 복합간섭계를 구성하였다. 복합간섭계는 광간섭계의 Zero crossing 지점부터 표준시편이 올려진 미소이동대의 이동거리를 변화된 위상값으로 읽고 그 변화량을 고분해능 변위 측정기인 엑스선 간섭계로 읽어들이는 구조로 구성된다. 본 연구에서는 미소이동대의 위치 변화와 관련된 광간섭계의 위상 안정도, 엑스선 간섭계 및 미소이동대의 위치 안정도 등이 나노미터 영역의 길이 측정에 매우 중요한 요인이 되므로, 미소이동대의 위치 변화시 정지상태에서의 위상 잠김 (phase locking) 안정도를 측정하였다. 마이켈슨 레이저간섭계의 한쪽 팔을 고정시키고 다른 한 팔은 미소이동대 위에 반사거울을 설치하여 미소이동대의 움직임을 측정하였다. 보다 안정된 위상잠김 상태를 확보하기 위하여 PID feedback loop controller를 사용하였다. 측정 결과 위상 변동폭이 0.022 degree 이하의 높은 위상잠김 안정도를 확보하였으며, 이를 길이단위로 환산하면 정지상태에서 약 0.02 nm 이하의 위치 안정도를 나타낸다.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.2006-2007
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• 2002

MEMS 공정을 이용하여 $SiN_x$를 지지층으로 한 $SiO_2$/Ta/PZT/Pt 의 박막 구조를 가지는 마이크로 켄틸레버를 제작하였다. 켄틸레버의 전기기계적 특성을 LDV (레이저 미소 변위 측정기)를 이용하여 측정하였으며, 이를 통해 전기기계적 거동을 분석하였다. 또한 무게 감지소자로서의 응용을 위해 Au의 증착을 통한 감도를 측정하였으며, streptavidin의 무게를 감지하기 위해 immobilization 공정을 거쳐 thiol 그룹 및 biotin을 표면에 고정화 시킨후 biotin-streptavidin 결합에 의한 전기기계적 신호 분석을 통해 생체 물질의 무게 감지 소자로의 응용을 평가하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.1
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• pp.13-23
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• 2015

The paper experimentally deals with the radial in-plane vibration characteristics of disk-shaped piezoelectric transducers. The radial in-plane motion, which is induced due to Poisson's ratio in the piezoelectric disk polarized in the thickness direction, was measured by using an in-plane laser vibrometer, and the natural frequencies were measured by using an impedance analyzer. The experimental results have been compared with theoretical predictions obtained by simplified theoretical and finite-element analyses. It appears that the fundamental mode of a piezoelectric disk transducer is a radial mode and its radial displacement distribution from the center to the perimeter is not monotonic but shows maximum slightly apart from the perimeter. The theoretically-calculated fundamental frequencies agree well with the finite-element results for small thickness-to-diameter ratio, and they are accurate within 7 % error for the ratio up to 0.4.