• Title/Summary/Keyword: depth calibration

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Development of a Time-selective Self-triggering Water Sampler and Its Application to In-situ Calibration of a Turbidity Sensor

  • Jin, Jae-Youll;Hwang, Keun-Choon;Park, Jin-Soon;Yum, Ki-Dai;Oh, Jae-Kyung
    • Journal of the korean society of oceanography
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    • v.34 no.4
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    • pp.200-206
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    • 1999
  • Seawater sampling is the primary task for the study of the marine environmental parameters that require shipboard or laboratory experiments for their analyses, and is also required for the calibration of some instruments for in situ measurement. A new automatic bottle (AUTTLE) is developed for seawater sampling at any desired time and water depth by self-triggering. Both any type of single or assembled mooring for 15 days and manual actuation by using a remote messenger as existing instantaneous single point water samplers are possible. Its sampling capacity and the resolution of time setting are 2 liters and 1 second, respectively. The result of a field experiment with an optical backscattering sensor (OBS) and a total of 14 AUTTLES for the in situ calibration of the OBS shows that the AUTTLE must improve our understanding on the behavior of the sand/mud mixtures in the environments with high waves and strong tides. The AUTTLE will serve as a valuable instrument in the various fields of oceanography, especially where synchronized seawater sampling at several sites is required and/or the information in storm period is important.

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Behavior of Lateral Loaded Piles with Pile shape and Length (말뚝형태 및 길이변화를 고려한 수평재하말뚝의 거동특성)

  • Hwang, Sung-Wook;Kim, Min-Kee;Kyung, Du-Hyun;Lee, Jun-Hwan
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1125-1131
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    • 2008
  • In this study, Calibration Chamber Tests for cast-in-place piles in sand were performed for measuring behavior properties of piles. These tests were examined effects of various parameters of soil conditions including the relative density($D_R$), the coefficient of earth pressure, and investigated differences between cylindrical pile and taper-shaped pile with the same volumes. The important effect factors of foundation behavior were investigated by considering embedded depth of piles and shapes of piles, and inspected details of lateral behavior of piles. These results were verified reliabilities of each methods for comparing the results estimated with tests and the results by proposed estimating solutions in the past.

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A Novel Image Sensing System for 3D Reconstruction (3차원 형상복원을 위한 새로운 시각장치)

  • 이두현;권인소
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.5
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    • pp.383-389
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    • 2000
  • This paper presents a stereo camera system that provides a Pair of stereo images using a Biprism. The equivalent of a stereo Pair of images is formed as the left and right halves of a single CCD image. The system is therefore cheap and extremely easy to calibrate since it requires only one CCD camera. An additional advantage of the geometrical set-up is that corresponding features lie on the same scanline automatically, The single camera and Biprism have led to a simple stereo system for which correspondence is very easy and which is accurate for nearby objects in a small field of view. Since we use only a single lens, calibration of the system is greatly simplified. Given the parameters in the Biprism-stereo camera system, we can reconstruct the 3-D structure using only the disparity between the corresponding points.

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Stereo vision mixed reality system using the multi-blob marker (다중 블럽 마커를 이용한 스테레오 비전 혼합현실 시스템의 구현)

  • 양기선;김한성;손광훈
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.1907-1910
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    • 2003
  • This paper describes a method of stereo image composition for mixed reality without camera calibration or complicate tracking algorithm. The proposed system tracks the panel which has blob makers, and composes virtual objects naturally using the method of texture mapping which is often used in geological computer graphics mapping when we do mapping 2D computer graphic data or man-made 2D images. The proposed algorithm makes it possible for us to compose virtual data even in the case that the panel is bent. For composing 3D object, the system uses depth information obtained from stereo image so that we do not need cumbersome procedure of camera calibration.

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A Study for the Fatigue Crack Growth Behavior of Concrete (콘크리트의 피로균열 성장거동에 관한 연구)

  • 김진근;김윤용
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.10a
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    • pp.101-107
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    • 1996
  • In this study, the wedge splitting test (WST) specimens with various strength levels were tested to investigate the fatigue crack growth behavior of concrete. Selected test variables were concrete compressive strength with 2 levels (28 MPa, 60 MPa, 100 MPa) and maximum fatigue loading with 2 levels (75%, 85%). Fatigue testing was preceded by fracture energy test and the crack growth was measured by means of the compliance calibration method, 60 WST specimens were cast for the fatigue test, and 6 companion cylinders ($\phi$100${\times}$ 200 mm) for each batch. In fatigue test, the frequency of loading cycle was 1 Hz, and the minimum fatigue loading level was 5~10 % of ultimate monotonic loading. On the basis of the experimental results, a fracture mechanics-based empirical relationships for fatigue crack growth rate (da/dN-$\Delta$KI relationships) were presented. In addition, the effect of initial notch depth on the fracture energy and the validity of compliance calibration technique for the WST were shown.

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High precision 3-dimensional object measurement using slit type of laser projector (슬리트형 레이저 투광기를 이용한 고정밀 3차원 물체계측)

  • Kim, Tae-Hyo;Park, Young-Seok;Lee, Chuy-Joong
    • Journal of Institute of Control, Robotics and Systems
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    • v.3 no.6
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    • pp.613-618
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    • 1997
  • In this paper, we designed a line CCD camera for a flying image, which is composed of a line CCD sensor(2048 cells) and a rotating mirror, and investigated its optical properties. We also made the 3-D image from the flying image which is made of 2-D image being juxtaposed to 1-D images obtained by the camera, and performed the calibration to acquire high precision 3-D data. As a result, we obtained the 3-D measurement system using the slit type of laser projector is available to measure the high precision shape of objects.

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A Study on Determination of the Area Function of Nano Indenter Tip with AFM (AFM을 이용한 나노 인덴터 팁의 면적함수 결정에 관한 연구)

  • 박성조;이현우;한승우
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.6
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    • pp.145-152
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    • 2004
  • Depth-sensing indentation is wifely used for evaluation of mechanical properties of thin films. It is generally accepted that the most significant source of uncertainty in nanoindentation measurement is the geometry of the indenter tip. Therefore the successful application of the technique requires accurate calibration of the indenter tip geometry. The direct measurement of geometry of a Berkovich indenter was determined using a atomic force microscope. The indentation geometrical calibration of contact area was performed by analyzing the indenter tip profile. The equations of area functions were proposed for nanoscale thin films..

Stereoscopic Video Compositing with a DSLR and Depth Information by Kinect (키넥트 깊이 정보와 DSLR을 이용한 스테레오스코픽 비디오 합성)

  • Kwon, Soon-Chul;Kang, Won-Young;Jeong, Yeong-Hu;Lee, Seung-Hyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.10
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    • pp.920-927
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    • 2013
  • Chroma key technique which composes images by separating an object from its background in specific color has restrictions on color and space. Especially, unlike general chroma key technique, image composition for stereo 3D display requires natural image composition method in 3D space. The thesis attempted to compose images in 3D space using depth keying method which uses high resolution depth information. High resolution depth map was obtained through camera calibration between the DSLR and Kinect sensor. 3D mesh model was created by the high resolution depth information and mapped with RGB color value. Object was converted into point cloud type in 3D space after separating it from its background according to depth information. The image in which 3D virtual background and object are composed obtained and played stereo 3D images using a virtual camera.

A New Camera System Implementation for Realistic Media-based Contents (실감미디어 기반의 콘텐츠를 위한 카메라 시스템의 구현)

  • Seo, Young Ho;Lee, Yoon Hyuk;Koo, Ja Myung;Kim, Woo Youl;Kim, Bo Ra;Kim, Moon Seok;Kim, Dong Wook
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.9 no.2
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    • pp.99-109
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    • 2013
  • In this paper, we propose a new system which captures real depth and color information from natural scene and implemented it. Based on it, we produced stereo and multiview images for 3-dimensional stereoscopic contents and introduced the production of a digital hologram which is considered to the next-generation image. The system consists of both a camera system for capturing images which correspond to RGB and depth images and softwares (SWs) for various image processings which consist of pre-processing such as rectification and calibration, 3D warping, and computer generated hologram (CGH). The camera system use a vertical rig with two paris of depth and RGB camera and a specially manufactured cold mirror which has the different transmittance according to wavelength for obtaining images with the same view point. The wavelength of our mirror is about 850nm. Each algorithm was implemented using C and C++ and the implemented system can be operated in real-time.

Optimization of Analytical Condition for Reliable and Accurate Measurement of Carbon Concentration in Carburized Steel by EPMA (EPMA를 이용한 침탄강의 정확하고 신뢰성 있는 탄소농도 측정을 위한 분석조건 최적화)

  • Gi-Hoon Kwon;Hyunjun Park;Byoungho Choi;Young-Kook Lee;Kyoungil Moon
    • Korean Journal of Materials Research
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    • v.33 no.3
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    • pp.106-114
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    • 2023
  • The carbon concentration in the carburized steels was measured by electron probe microanalysis (EPMA) for a range of soluted carbon content in austenite from 0.1 to 1.2 wt%. This study demonstrates the problems in carbon quantitative analysis using the existing calibration curve derived from pure iron (0.008 wt%C) and graphite (99.98 wt%C) as standard specimens. In order to derive an improved calibration curve, carbon homogenization treatment was performed to produce a uniform Kα intensity in selected standard samples (AISI 8620, AISI 4140, AISI 1065, AISI 52100 steel). The trend of detection intensity was identified according to the analysis condition, such as accelerating voltage (10, 15, 30 keV), and beam current (20, 50 nA). The appropriate analysis conditions (15 keV, 20 nA) were derived. When the carbon concentration depth profile of the carburized specimen was measured for a short carburizing time using the improved calibration curve, it proved to be a more reliable and accurate analysis method compared to the conventional analysis method.