• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2006년도 추계학술대회 논문집
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• pp.1-6
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• 2006

Single-Camera Stereoscopic Vision three-dimensional measurement system has been developed based upon 30-PTV algorithm. The system consists of one camera $(1k\times1k)$ and a host computer. To attain three-dimensional measurements a plate having stereo holes has been installed inside of the lens system. Three-dimensional measurements was successfully attained by adopting the conventional 30-PTV camera calibration methods. As applications of the constructed measurement system, a water droplet mixed with alcohol was constructed on a transparent plastic plate with the contacted fluid diameter 4mm, and the particles motions inside of the droplet have been investigated with the constructed measurement system. The measurement uncertainty of the constructed system was 0.04mm, 0.04mm and 0.09mm for X, Y and Z coordinates.

• Journal of Information Processing Systems
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• 제18권2호
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• pp.223-234
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• 2022

The evaluation of the print quality of 3D printing has traditionally relied on manual work using dimensional measurements. However, the dimensional measurement method has an error value that depends on the person who measures it. Therefore, we propose the design of a new print quality measurement method that can be automatically measured using the field-of-view (FOV) model and the intersection over union (IoU) technique. First, the height information of the modeling is acquired from a camera; the output is measured by a sensor; and the images of the top and isometric views are acquired from the FOV model. The height information calculates the height ratio by calculating the percentage of modeling and output, and compares the 2D contour of the object on the image using the FOV model. The contour of the object is obtained from the image for 2D contour comparison and the IoU is calculated by comparing the areas of the contour regions. The accuracy of the automated measurement technique for determining, which derives the print quality value was calculated by averaging the IoU value corrected by the measurement error and the height ratio value.

• 대한공간정보학회지
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• 제20권1호
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• pp.43-51
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• 2012

수변공간 및 수자원에 대한 효율적 활용 요구가 증대됨에 따라 하천의 수리적인 특성을 보다 정밀하게 모의하고 이를 활용한 의사결정이 필요하다. EFDC 모형은 이러한 의사결정을 지원하기 위한 다차원 수리모형으로 3차원 정밀지형을 활용하여 수체의 수리적인 특성을 분석할 수 있다. 그러나 EFDC 모형의 입력자료로 활용되는 3차원 정밀지형의 경우, 측량간격과 지형보간기법에 의해 많은 영향을 받게 되며 3차원 정밀지형의 변화에 따라 대상 수체의 수리적인 특성이 영향을 받게 된다. 이에 본 연구에서는 다른 측량간격 및 지형보간기법에 따라 도출된 3차원 정밀지형이 EFDC 모형의 모의결과에 미치는 영향을 검토하였다. 연구 대상지역은 낙동강 금호강 유입구간이며, 검토 사상은 2006년 강우사상에 대한 수치모의를 수행하고, 면적-고도 곡선, 수위 및 유속의 모의결과를 비교 분석하였다. 분석결과, 동일한 측량 간격에서는 지형보간기법에 따른 면적고도곡선의 차이는 크지 않았으나, 측량 간격이 160m에서 모든 보간기법에서 차이가 발생하였고 측량간격이 80m 이상이 되면 하상단면의 변화가 발생하였다. 또한, 수위의 경우에 Kriging을 제외한 나머지 기법은 해상도에 따른 차이가 크지 않았고, Kriging은 160m 측량간격에서 다른 기법에 비해 차이가 크게 나타났다. 유속의 경우, 80m 측량간격이상에서 각 보간기법별 차이가 나타나기 시작했으며 160m 측량간격에서 Kriging은 다른 보간기법과 큰 차이를 보이는 것으로 나타났다.

• 대한전자공학회논문지
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• 제25권3호
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• pp.302-307
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• 1988

A noble interconnection line capacitance measurement method to be able to remove the measurement errors from the probe pad to substrate stray capacitance has been proposed and verified. The measurement errors in the capacitance measurement, which usually be involved from the probe pad to substrate stray capacitance, can easily be removed by isolating the metal probe pad from the substrate with a grounded shield plate between the probe pad the substrate. The measurement results by using this improved capacitance measurement method were compared with the calculations by two-dimensional computer simulations.

• 한국음향학회지
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• 제13권3호
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• pp.41-50
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• 1994

이 연구에서는 3차원 음향 인텐시티를 동시에 측정할 수 있는 프로브를 이용하여 음향 인텐시티를 측정할 때 필연적으로 발생하는 오차를 컴퓨터의 수치계산으로 검토하였다. 이 3차원 음향 인텐시티 프로브는 Suzuki등에 의해 제안된 4개의 마이크로폰으로 구성된 것이고, 수치계산에서는 이상적인 점음원과 유한 크기를 가지는 면음원에 대해서 프로브의 각 축방향 및 임의의 방향에 대한 측정오차를 근거리 음장에서 분석하였다. 그 결과, 점음원의 경우 측정거리가 프로브를 구성하는 마이크로폰 사이의 간격보다 약 2.5배 이상 떨어진 거리에서 오차 1dB 이하의 정밀한 측정을 할 수 있었고, 유한 크기의 면음원의 경우, 면음원의 한 변의 길이가 0.02m이상일 때 근거리 음장의 측정오차가 크게 감소하기 시작하여, 한 변의 길이가 0.2m일 때 측정거리가 마이크로폰 사이의 간격보다 0.67배로 근접하여 측정하여도 1dB 이하의 정밀한 측정이 가능한 것으로 평가되어 이 프로브의 근거리 음장 측정의 유효성이 확인되었다.

• Journal of Cardiovascular Imaging
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• 제30권3호
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• pp.197-201
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• 2022

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.99-100
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• 2000

We measured 3-dimensional images of the light emitted from plasma display panel by using newly proposed scanned point detecting method (SPDM). From the 3-dimensional emission images, we know that as the sustain voltage increases, intensity of light detected without phosphor increases and the position of the maximum intensity moves to the outside from the electrode gap. Also, we know that 2-dimensional simulations under the assumption that neglects the Y axis variation do not agree with 3-dimensional experiment results.

• 한국해양공학회지
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• 제32권2호
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• pp.106-115
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• 2018

The forward and afterward parts of ships and offshore structures are designed to improve the fuel consumption performance. These are made of curved plates with a large thickness. If a fabricated curved plate has some dimensional errors, a lot of additional cost is incurred in the assembly process. Thus, an accurate dimensional assessment is very important for fabrication. In this paper, we propose an assessment method for the dimensional quality management of curved plates. This can be applied to data measured using a variety of three-dimensional instruments, with boundary measurement points automatically classified and sorted to create a measurement surface. The assessment is evaluated after matching the CAD surface and the measured surface considering constrained conditions. The fabrication assessment is evaluated as a probability of how much the tolerance is satisfied.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2005년도 추계학술대회 논문집
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• pp.58-63
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• 2005

Three-dimensional vortical structures in the wake behind a road vehicle has been visualized with the help of two-dimensional PIV measurement data. A three-dimensional velocity field has been reconstructed from several sectional measurement data in the x-y, y-z and z-x planes. Isovorticity surface observed by stacking only the sectional data in each plane, does not show the vortical structures within the recirculation region but represents only the strong shear flows. Thus, in the present study, the velocity component normal to the x-y plane is obtained by interpolating those velocities in the z-x plane. Then, a $\lambda_{2}$-definition which captures the local pressure minimum or vortex core, is applied to visualize the vortices in the recirculation region. The final results represent a successful configuration for the three-dimensional vortices.

• 한국정밀공학회지
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• 제17권1호
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• pp.129-137
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• 2000

In this paper, a new method of noncontact measurement has been developed for a 3 dimensional topography in semiconductor wafer, implementing a new optical probe based on the precision defocus measurement. The developed technique consists of the new optical probe, precision stages, and the measurement/control system. The basic principle of the technique is to use the reflected slit beam from the specimen surface, and to measure the deviation of the specimen surface. The defocusing distance can be measured by the reflected slit beam, where the defocused image is measured by the proposed optical probe, giving very high resolution. The distance measuring formula has been proposed for the developed probe, using the laws of geometric optics. The precision calibration technique has been applied, giving about 10 nanometer resolution and 72 nanometer of four sigma uncertainty. In order to quantitize the micro pattern in the specimen surface, some efficient analysis algorithms have been developed to analyse the 3D topography pattern and some parameters of the surface. The developed system has been successfully applied to measure the wafer surface, demonstrating the line scanning feature and excellent 3 dimensional measurement capability.