• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.527-532
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• 2010

This paper is concerned with the measurement of static and dynamic displacement by image processing(IP) and study for prediction method of velocity and acceleration. To measure the displacement visually, the measurement system consists of a telephoto zoom camera, ccd image device and a computer. The specific target on the white board is used to calculate the displacement of the structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the pixel-size of image. In this paper, we developed for the displacement measurement using the image processing method. The proposed method enables us to measure the vibration measurement, velocity and acceleration directly without any contact. The current resolution of the displacement measurement is limited to 1/100 millimeter scale.

• 한국소음진동공학회논문집
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• 제15권3호
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• pp.329-333
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• 2005

This paper is concerned with the measurement of low-frequency vibrations of structures using the image processing method. To measure the vibrations visually, the measurement system consists of a camera, an image grabber board, and a computer. The specific target installed on the structure is used to calculate the vibration of structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the size of image. In this paper, we propose the methodology for the vibration measurement using the image processing method. The method enables us to measure the displacement directly without any contact. The current resolution of the vibration measurement is limited to sub centimeter scale. However, the frequency bandwidth and resolution can be enhanced by a high-speed and high-resolution image processing system.

• 복식
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• 제53권5호
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• pp.1-12
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• 2003

This paper proposes a system for measuring the 3D human bodies using the multiple 2D images. The system establishes the multiple image input circumstance from the digital camera for image measurement. The algorithm considering perspective projection leads us to estimate the 3D human bodies from the multiple 2D images such as frontal. side and rear views. The results of the image measurement is compared those of the direct measurement and the 3D scanner for the total 40 items (12 heights, 15 widths and 13 depths). Three persons measure the 40 items using the three measurement methods. In comparison of the results obtained among the measurement methods and the persons, the results between the image measurement and the 3D scanner are very similar. However, the errors for the direct measurement are relatively larger than those between the image measurement and the 3D scanner. For example, the maximum errors between the image measurement and the 3D scanner are 0.41cm in height, 0.39cm in width and 0.95cm in depth. The errors are acceptable in body measurement. Performance of the image measurement is superior to the direct. because the algorithm estimates the 3D positions using the perspective projection. In above comparison, the image measurement is expected as a new method for measuring the 3D body, since it has the various advantages of the direct measurement and 3D scanner in performance for measurement as well as in the devices, cost, Portability and man power.

• 한국정밀공학회지
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• 제32권12호
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• pp.1039-1047
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• 2015

Contact type sensors (e.g., displacement sensor and strain gauge) were typically used to evaluate the safety and mechanical properties in machines and construction. However, those contact type sensors have been constrained because of measurement problems such as surface roughness, temperature, humidity, and shape. The Digital Image Correlation (DIC) measurement system is a vision measurement system. This measurement system uses the taken image using a CCD camera and calculates the image correlation between the reference image and the deformed image under external force to measure the displacement and strain rates. In this paper, we discuss methods to improve the measurement precision of the digital image correlation measurement system. A tensile test was conducted to compare the precision improvement effects, by using the universal test machine and the DIC measurement system, with the use of subpixel algorithms, i.e., the Coarse Fine Search (CFS) algorithm and the Peak Finding (PF) algorithm.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 제5회 박판성형 SYMPOSIUM
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• pp.34-39
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• 2006

An automated surface-strain measurement system, named ASIAS, was developed by using the image processing and stereo vision techniques in the previous studies by the corresponding author and his coworkers. This system has been upgraded mainly to improve the accuracy through image enhancement, sub-pixel measurement, surface smoothing, etc., since the first version was released. The present study has still more improved the convenience of users as well as the accuracy of measurement by processing high resolution images 8 mega pixels or more which can be easily obtained from a portable digital steal camera. It is proved that high resolution image processing greatly decreases the measurement error and gives strain data without considerable deterioration of accuracy even when the deformed grids to be measured and the master grids for camera calibration are captured together in the same image, making the whole process of strain measurement much simpler.

• 한국소음진동공학회논문집
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• 제21권2호
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• pp.112-119
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• 2011

This paper is concerned with the measurement of static and dynamic displacement by image processing(IP) and study for prediction method of velocity and acceleration. To measure the displacement visually, the measurement system consists of a telephoto zoom camera, CCD(charge coupled device) image device and a computer. The specific target on the white board is used to calculate the displacement of the structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the pixel-size of image. In this paper, we developed for the displacement measurement using the image processing method. The proposed method enables us to measure the vibration displacement, velocity and acceleration directly without any contact. The current resolution for the displacement measurement can be seen from the results.

• 한국방사선학회논문지
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• 제14권2호
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• pp.111-120
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• 2020

병원에서 사용하는 X선 장비는 X선 장비의 능력 연구와 더불어 출력되는 영상의 화질까지도 분석하는 연구가 활발히 진행되어야 한다. 영상의학과 장비의 X-Ray기계나 CT, MRI와 같은 장비의 후향적 이미지 분석은 활발히 진행되었으나 혈관조영실의 혈관조영장비를 이용하여 획득한 영상의 화질 측정은 팬텀을 이용하여 측정하는 방법이 대부분이고 실제 환자에게 촬영된 후의 영상에 관한 화질 측정은 미비한 실정이며 정확한 화질 측정 방법에 관한 연구가 현저히 부족한 상태이다. 따라서 본 연구를 통해 관상동맥 조영술 후 획득된 영상의 화질측정 방법을 고안한 연구를 진행해 시술자에게 질 높은 영상을 제공하고자 연구를 진행하게 되었다. 사용된 장비 및 프로그램은 혈관 조영 검사 장비(Axiom Artis Zee Ceiling)와 Image J프로그램을 사용하였다. 대상으로는 관상동맥 조영술 후 PACS프로그램에 자동 저장된 영상들을 대상으로 하였다. 화질 측정 방법으로는 Image J프로그램을 이용했을 때 관상동맥 조영술 중 좌 관상동맥의 주요 혈관들이 가장 잘 펼쳐져 보이는 각도의 영상인 AP Caudal 30°영상과 우 관상동맥의 혈관이 가장 잘 펼쳐져 보이는 LAO 30° 영상을 선택하여 선택된 영상의 배경영역(Background)과 관심영역(ROI)을 측정하기 위해 혈관과 간, 폐 등의 음영 중복이 가장 최소화 되는 구간을 찾아 측정하는 방법에 관한 기준을 제시하였다. 결론적으로 혈관 조영 영상의 화질측정 분석 방법은 정확히 제시되어 있는 기준이 없기 때문에 시술자에게 질 좋은 영상을 제공하기 위해선 그 장비의 기술자들뿐 아니라 실제로 사용하는 사용자들이 연구자가 되어 다양한 방법으로 화질측정에 관한 연구를 진행해야만 환자에게도 우수한 영상을 제공할 수 있을 것으로 사료된다.

• Smart Structures and Systems
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• 제17권6호
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• pp.935-956
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• 2016

With the help of advanced image acquisition and processing technology, the vision-based measurement methods have been broadly applied to implement the structural monitoring and condition identification of civil engineering structures. Many noncontact approaches enabled by different digital image processing algorithms are developed to overcome the problems in conventional structural dynamic displacement measurement. This paper presents three kinds of image processing algorithms for structural dynamic displacement measurement, i.e., the grayscale pattern matching (GPM) algorithm, the color pattern matching (CPM) algorithm, and the mean shift tracking (MST) algorithm. A vision-based system programmed with the three image processing algorithms is developed for multi-point structural dynamic displacement measurement. The dynamic displacement time histories of multiple vision points are simultaneously measured by the vision-based system and the magnetostrictive displacement sensor (MDS) during the laboratory shaking table tests of a three-story steel frame model. The comparative analysis results indicate that the developed vision-based system exhibits excellent performance in structural dynamic displacement measurement by use of the three different image processing algorithms. The field application experiments are also carried out on an arch bridge for the measurement of displacement influence lines during the loading tests to validate the effectiveness of the vision-based system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.503-507
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• 2004

This paper is concerned with the measurement of low-frequency vibrations of structures using the image processing method. To measure the vibrations visually, the measurement system consists of a camera, an image grabber board, and a computer. The specific target installed on the structure is used to calculate the vibration of structure. The captured image is then converted into a pixel-based data and then analyzed numerically. The limitation of the system depends on the image capturing speed and the size of image. In this paper, we discuss the methodology for the vibration measurement using the image processing method. The method enables us to measure the displacement directly without any contact. The resolution of the vibration measurement can be refined but limited to the sub centimeter displacement.

• 한국과학교육학회지
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• 제37권6호
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• pp.1051-1061
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• 2017

이미지는 대상에 대해 자신이 경험한 종합적인 결과이며 의식의 표면에 갖고 있는 심상을 의미한다. 교과에 대한 이미지는 그 교과를 학습하는 데 중요한 영향을 미친다. 학습자들이 갖고 있는 교과에 대한 이미지 분석은 교수 학습의 방향성을 결정하는 좋은 자료가 될 것이다. 이 연구의 목적은 물리 이미지 측정도구를 개발하고 적용하여 교육적 시사점을 논의하는 데 있다. 연구 방법은 의미분석법에 의해 물리 이미지 측정도구를 개발하고, 중등 예비 물리교사에게 적용한다. 연구 대상은 사범대학교 물리교육 전공 1학년 39명, 2학년 31명, 3학년 37명, 4학년 38명이고, 전체 남학생은 82명, 여학생은 63명 총 145명이다. 연구결과 물리 이미지 측정도구는 '관심', '느낌', '범위', '평가', '관점'의 5개 요소, 25문항으로 구성되었다. 개발한 물리 이미지 측정도구를 중등 예비교사들에게 적용한 결과 성별, 학년별에 따라 요소별로 통계적인 유의미한 차이가 나타났다. 물리 이미지의 '관심', '느낌' 요소에서 남학생이 여학생 보다 통계적으로 유의미하게 높게 나타났다. 학년별에서는 물리 이미지의 '범위' 요소에서 2학년이 4학년보다 통계적으로 높은 것으로 나타났다. 끝으로 물리 이미지 측정도구 활용의 유용성 및 물리 이미지 분석에 대한 교육적 시사점을 논의하였다.