• 한국정밀공학회지
• /
• 제22권12호
• /
• pp.205-210
• /
• 2005

This paper addresses the correlation between the change of file size and the scanning path build time by the slicing height of STL file. Though the study about STL file has been achieved quite actively scanning path build time using STL file is not investigated so much to be satisfied. The file size depends on the number of polygon created by the slicing height specified. And this number of polygons increases in a regular rate. The correlation between the number of polygons and the scanning path build time is examined and verified.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.114-118
• /
• 2004

This paper is compared the build time of scanning path as to laminate height of the SLC and STL file. The STL file improve the surface roughness according to slicing height. But it have the fault spending long time to the creation of scanning path by being lower slicing height. So we proposed the SLC file to improve this fault. Therefore this paper showed to the build time of scanning path by the increase of peace using the jewellery model.

• 한국연소학회지
• /
• 제8권3호
• /
• pp.24-30
• /
• 2003

A convolution algorithm combined with Fourier transformation has been applied to the tomographic reconstruction of asymmetric soot structure to identify the local soot volume fraction distribution. Line-of-sight integrated data from light extinction measurement with multi-angular scanning formed basic information for the deconvolution. Multi-peak following interpolation technique was applied to obtain the effect of increasing number of scanning angles. Height-by-height reconstructed soot volume fraction distribution was compared with laser-induced incandescence signals.

• 한국멀티미디어학회논문지
• /
• 제21권8호
• /
• pp.864-875
• /
• 2018

In this paper, we propose a measurement method for height of white light scanning interferometer using deep learning. In order to measure the fine surface shape, a three-dimensional surface shape measurement technique is required. A typical example is a white light scanning interferometer. In order to calculate the surface shape from the measurement image of the white light scanning interferometer, the height of each pixel must be calculated. In this paper, we propose a neural network for height calculation and use virtual data generation method to train this neural network. The accuracy was measured by inputting 57 actual data to the neural network which had completed the learning. We propose two new functions for accuracy measurement. We have analyzed the cases where there are many errors among the accuracy calculation values, and it is confirmed that there are many errors when there is no interference fringe or outside the learned range. We confirmed that the proposed neural network works correctly in most cases. We expect better results if we improve the way we generate learning data.

• 한국측량학회:학술대회논문집
• /
• 한국측량학회 2004년도 춘계학술발표회논문집
• /
• pp.15-26
• /
• 2004

The calibration for systematic error in LiDAR is crucial for the accuracy of airborne laser scanning. The main error is the misalignment of platforms between INS(Inertial Navigation System) and Laser scanner For planimetrical calibration of LiDAR, the building is good feature which has great changes in height and continuous flat area in the top. The planimetry error(pitch, roll) is corrected by adjustment of height which is calculated from comparing ground control points(GCP) of building to laser scanning data. We can know scale correction of laser range by the comparison of LiDAR data and GCP is arranged at the end of scan angle where maximize the height error. The area for scale calibration have to be large flat and have almost same elevation. At 1000m for average flying height, The Accuracy of laser scanning data using LiDAR is within 110cm in height and ${\pm}$50cm in planmetry so we can use laser scanning data for generating 3D terrain surface, expecically digital surface model(DSM) which is difficult to measure by aerial photogrammetry in forest, coast, urban area of high buildings

• Korean Journal of Radiology
• /
• 제1권2호
• /
• pp.110-113
• /
• 2000

Objective: The purpose of this study was to determine, when measuring prostate volume by TRUS, whether height is more accurately determined by transaxial or midsagittal scanning. Materials and Methods: Sixteen patients who between March 1995 and March 1998 underwent both preoperative TRUS and radical prostatectomy for prostate cancer were included in this study. Using prolate ellipse volume calculation (height × length × width × 𝜋/6), TRUS prostate volume was determined, and was compared with the measured volume of the specimen. Results: Prostate volume measured by TRUS, regardless of whether height was determined transaxially or midsagittally, correlated closely with real specimen volume. When height was measured in one of these planes, a paired t test revealed no significant difference between TRUS prostate volume and real specimen volume (p = .411 and p = .740, respectively), nor were there significant differences between the findings of transaxial and midsagittal scanning (p = .570). A paired sample test, however, indicated that TRUS prostate volumes determined transaxially showed a higher correlation coefficient (0.833) and a lower standard deviation (9.04) than those determined midsagittally (0.714 and 11.48, respectively). Conclusion: Prostate volume measured by TRUS closely correlates with real prostate volume. Furthermore, we suggest that when measuring prostate volume in this way, height is more accurately determined by transaxial than by midsagittal scanning.

• 한국산림과학회지
• /
• 제112권3호
• /
• pp.363-373
• /
• 2023

산림 바이오매스 조사는 탄소흡수원으로서의 산림을 평가하고 관리하기 위해 주기적으로 수행된다. 원격탐사의 한 종류인 라이다는 적은 노동력으로 객관적인 산림 구조 정보를 획득할 수 있어, 최근 라이다(LiDAR, Light Detection and Ranging)를 이용한 산림 조사가 주목받고 있다. 본 연구에서는 임분 상하층 바이오매스 추정에 백팩형 라이다(Backpack Laser Scanning, BPLS)와 드론 라이다(Unmanned Aerial Vehicle Laser Scanning, UAV-LS)를 이용하는 방법을 제시하고 그 정확도를 평가하였다. 상층의 경우 BPLS와 UAV-LS의 흉고직경과 수고 추정 정확도를 분석하였고, 하층의 경우 BPLS 데이터에서 추출한 수직구조 변수 중 최상의 변수 조합으로 하층 바이오매스를 추정하는 다중회귀모델을 개발하였다. 그 결과, BPLS는 흉고직경을 높은 정확도로 추정하였지만(R² =0.92) 수고는 과소 추정하였다(R² =0.63, Bias=-5.56 m). UAV-LS는 BPLS보다 더 높은 수고 추정 정확도를 보였다(R² =0.91). 하층의 경우 점들의 평균 높이와 라이다 데이터를 같은 높이를 가진 10개의 층으로 나누었을 때 아래에서 네 번째 층의 점 밀도를 의미하는 변수가 선택되어 모델이 개발되었으며, 교차검증 결과 결정계수 값은 0.68로 나타났다. 본 연구의 결과는 BPLS와 UAV-LS를 이용한 임분의 상하층 바이오매스 조사 방법이 기존의 조사 방식을 효과적으로 대체할 수 있음을 시사한다.

• 패션비즈니스
• /
• 제16권1호
• /
• pp.150-159
• /
• 2012

This study intend to analyze differences between 3D body scanning sizes and direct measurement sizes of same subjects. The subjects of study are female students of university in China. 3D data analyze as a 3D Body Measurement Soft System. The conclusion found is as below: In case of circumferences, error between direct-measurement size and 3D body scanning size is from 4.9mm to 62.2mm. The neck circumference size of directmeasurement is bigger than 3D body scanning size. The height error range is from 0.6mm to 51mm. Height of underbust, waist and hip are that direct-measurement sizes are higher than 3D body scanning sizes. Gap of width is from 3.8mm to 21.9mm. The gap range is too narrow relatively to others. Only direct-measurement size of neck width is wider than 3D body scanning size. Error range of length is from 0.3mm to 41.8mm. 3D body scanning sizes of lateral neck to waistline, upperarm length, arm length, neck shoulder point to breast point, shoulder center point to breast point, lateral shoulder to breast point are longer than direct-measurement sizes. They have a negative margin of error. I intend to set up same measurement point between direct-measurement and 3D body scanning but they have some errors because direct-measurement point is applied by a person. 3D body scanning measurement point is settled by automatic system. A measurement point of direct-measurement and 3D body scanning isn't unite. So we need to make a standard of setting up measurement points.

• International Journal of Precision Engineering and Manufacturing
• /
• 제9권3호
• /
• pp.27-32
• /
• 2008

This paper describes a contact atomic force microscope (AFM) that can be used for high-speed precision measurements of microstructured surfaces. The AFM is composed of an air-bearing X stage, an air-bearing spindle with the axis of rotation in the Z direction, and an AFM probe unit. The traversing distance and maximum speed of the X stage are 300 mm and 400 mm/s, respectively. The spindle has the ability to hold a sample in a vacuum chuck with a maximum diameter of 130 mm and has a maximum rotation speed of 300 rpm. The bandwidth of the AFM probe unit in an open loop control circuit is more than 40 kHz. To achieve precision measurements of microstructured surfaces with slopes, a scanning strategy combining constant height measurements with a slope compensation technique is proposed. In this scanning strategy, the Z direction PZT actuator of the AFM probe unit is employed to compensate for the slope of the sample surface while the microstructures are scanned by the AFM probe at a constant height. The precision of such a scanning strategy is demonstrated by obtaining profile measurements of a microstructure surface at a series of scanning speeds ranging from 0.1 to 20.0 mm/s.

• 한국정밀공학회지
• /
• 제31권11호
• /
• pp.999-1006
• /
• 2014

In this investigation, we explain the sub-sampling technique of white light scanning interferometry (WLSI) to improve the measurement speed. In addition to the previous work using Fourier domain analysis, several methods to extract the height from the correlogram of WLSI are described with the sub-sampling technique. Especially, Fourier-inverse Fourier transformation method adopting sub-sampling technique is proposed and the phase compensation technique is verified with simulation and experiments. The main advantage of sub-sampling is to speed up the measurements of WLSI but the precision such as repeatability is slightly poor. In case of measuring the sample which has high height step or difference, the proposed technique can be widely used to reduce the measurement time.