• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.549-557
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• 2022

Due to harsh conditions of construction site, understanding of current feature of terrain and other infrastructures is critical issue for site managers. However, because of difficulties in acquiring the geographical information of the construction sites such as large sites and limited capability of construction workers, comprehensive site investigation of current feature of construction site is not an easy task for construction managers. To address these circumstances of construction sites, this study deduce difficulties and applicabilities of unmanned aerial vehicle in the area of construction site management. To confirm applicability of UAV in civil construction project, case study have been conducted on the road construction project. The result of case study proved that the developed system is one of promising technologies that has been studied in construction site management. To improve applicability of UAV for construction and process management information, law and technical issues will be an important area of future study.

• Proceedings of the Korea Information Processing Society Conference
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• 2024.05a
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• pp.440-443
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• 2024

한의학의 증상을 파악하는 한의 변증 진단에서 혀의 형태와 색상을 파악하는 것에서 설질과 설태의 색상을 파악하는 것이 핵심이다. 혀 촬영 장치로 촬영하더라도 조명의 빛 종류와 빛 강도, 위치에 따라 컬러가 변환됨에 따라 혀 취득장치의 컬러교정이 필요하다. 컬러교정을 하지만, 오버피팅, 측정 오류와 노이즈 또는 색상 공간의 불균형으로 컬러의 왜곡이 발생할 수 있다. 이 연구에서는 24개의 patch 중에서 오류를 최소화할 수 있는 patch를 선정하는 최적화의 방법을 제시하려 하였다. 24개 patch 중 몇 개의 선택한 patch의 평균값을 구하여, 기준 값으로 변환시키는 변환 행렬을 구하고, 교정 값을 구하고, 교정된 24 patch 값의 평균과 기준 값과의 오차를 구하여 최소가 되는 변환 행렬을 구하였다. 이 방법은 컬러 챠트의 개수를 줄여 장치의 부피를 줄이는데 활용될 수 있다. 또한 이 방법은 외부의 빛이 차단된 촬영장치에서 활용되었지만, 조명조건이 안정된 개방된 공간에서도 스마트폰을 이용하여 촬영하는데 활용 가능할 것으로 예상된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.1
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• pp.53-62
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• 2016

In recent years, UAV Photogrammetry based on an ultra-light UAS(Unmanned Aerial System) installed with a low-cost compact navigation device and a camera has attracted great attention through fast and accurate acquirement of geo-spatial data. In particular, UAV Photogrammetry do gradually replace the traditional aerial photogrammetry because it is able to produce DEMs(Digital Elevation Models) and Orthophotos rapidly owing to large amounts of high resolution image collection by a low-cost camera and image processing software combined with computer vision technique. With these advantages, UAV-Photogrammetry has therefore been applying to a large scale mapping and cadastral surveying that require accurate position information. This paper presents experimental results of an accuracy performance test with images of 4cm GSD from a fixed wing UAS to demarcate parcel boundaries in agricultural area. Consequently, the accuracy of boundary point extracted from UAS orthoimage has shown less than 8cm compared with that of terrestrial cadastral surveying. This means that UAV images satisfy the tolerance limit of distance error in cadastral surveying for the scale of 1: 500. And also, the area deviation is negligible small, about 0.2%(3.3m²), against true area of 1,969m² by cadastral surveying. UAV-Photogrammetry is therefore as a promising technology to demarcate parcel boundaries.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.1124-1132
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• 2009

We proposed a new method to improve the resolution of elemental image set in the integral imaging system using super-resolution image reconstruction method. Adjacent elemental images have same image region which is projected from the common area of object. These projected images in the elemental image can be used for low resolution images of super-resolution method. Two methods for resolution improvement of elemental image set using super-resolution method are proposed. One is super-resolution among the elemental image sets and the other is among the elemental images. Simulation results are compared with resolution improved elemental image set using interpolated method.

• Geophysics and Geophysical Exploration
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• v.6 no.3
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• pp.126-133
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• 2003

High-resolution shallow marine seismic surveys have been carried out for the resources exploration, engineering applications and Quaternary mapping. To improve the resolution of subsurface structure image, multichannel digital technique has been applied. The quality of the image depends on the vertical and horizontal resolution and signal to noise (S/N) ratio which are associated with the data acquisition parameters such as sample interval, common midpoint (CMP) interval and CMP fold. To understand the effect of the acquisition parameters, a test survey was carried out off Yeosu and the acquired data were analyzed. A 30 $in^3$ small air gun was used as a seismic source and 8 channel streamer cable with a 5 m group interval was used as a receiver. The data were digitally recorded with a shot interval of 2 s and sample interval of 0.1 ms. The acquired data were resampled with various sample intervals, CMP intervals and CMP folds. The resampled data were processed, plotted as seismic sections and compared each other. The analysis results show that thin bed structure with ${\~}1m$ thickness and ${\~}6^{\circ}$ slope can be imaged with good resolution and continuity and low noise using the acquisition parameters with a sample interval shorter than 0.2 ms, CMP interval shorter than 2.5 m and CMP fold more than 4. Because seismic resolution is associated with the acquisition parameters, the quality of the subsurface structure can be imaged successfully using suitable and optimum acquisition parameters.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.1
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• pp.49-57
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• 2012

An image reconstruction algorithm is proposed to estimate transmitted original images from images displayed on a video terminal. The proposed algorithm acquires images that are displayed on video terminal screens by using a camera. The transmitted images are then estimated with the acquired images. However, camera-acquired images exhibit geometric and color distortions caused by characteristics of the camera and display devices. We make use of a geometric distortion correction algorithm that exploits homography and color distortions using a weighted-linear model. The experimental results show that the proposed algorithm yields promising estimation performance with respect to the peak signal-to-noise ratio (PSNR). PSNR values of the estimated images with respect to the corresponding original images range from 28-29 dB.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1149-1154
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• 2006

증강현실 (AR: Augmented Reality)은 카메라를 통하여 현실의 공간에 가상의 물체를 삽입하는 기술로 사용자에게 컴퓨터상에서 정보를 보강해 줌으로서 사용자가 카메라로 보이는 환경에 대한 추가적인 정보를 취득 할 수 있게 해주는 분야이다. 가상환경(Virtual Reality) 및 혼합영상(Mixed Reality)을 이용해 보다 사실감 있는 가상의 영상을 일상 생활에 접목하려는 기술들이 부각되며 활발한 연구가 이루어 지고 있는데 이러한 시도는 일상생활의 다양한 분야에 적용이 되고 있다. 본 논문에서는 카메라로 취득된 화면상에 사용자의 움직임, 즉 사용자가 대상되는 마커를 삽입하고 컨트롤할 수 있는 음악플레이어를 구현한다. 사용자가 키보드나 마우스 등의 입력장치가 아닌 카메라에서 보여지는 마커의 움직임으로 원하는 음악을 플레이 할 수 있는 방법을 제안하고자 한다. 실시간으로 입력되는 카메라상의 프레임에서 대상되는 마커의 움직임을 찾고 그 대상물체 위에 정보를 증강시켜주고, 그 음악을 화면상에 사용자의 마커 움직임을 통해서 제어하는 방법이다.

• Journal of the Korean Magnetics Society
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• v.27 no.1
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• pp.35-40
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• 2017

Kerr microscopy was assembled to observe magnetic domain image of ultra thin 3 %Si-Fe by using parts of an optical microscope. Digital images were obtained from CCD camera attached to the microscopy. A method was suggested to decide a boundary between magnetic domain regions in this study. The method was using some operations such as subtraction, integration and least mean square approximation for pixel values in the digital image. The method has a strong point that high priced image processor is not needed in the Kerr microscopy system. From the results that three different domain walls were observed and magnetic flux density of 0.085 [T], this method could be applied in the magnetic domain regions having a straight $180^{\circ}$ domain wall.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.227-228
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• 2008

본 논문에서는 조명 변화가 있는 스테레오 이미지에 대하여 레티넥스 알고리즘을 이용하여 효과적으로 3차원 정보를 추출하는 방법을 제안한다. 이미지나 비데오는 영상 취득시 여러 가지 원인에 의하여 조명 변화를 겪게 된다. 이미지나 비데오를 촬영하는 시간 간격 차이, 촬영 각도 차이, 촬영 장치의 변화 등이 그 원인이다. 기존의 스테레오 알고리즘들은 정합하려는 영상들 사이에 컬러 일치성을 가정하고 있으므로, 이러한 조명 변화의 영향을 받는 이미지들에 대해서 3차원 정보를 추출하면 적지 않은 에러가 발생하게 된다. 따라서, 이러한 문제를 해결하기 위하여 레티넥스 기법을 이용하여 이러한 변화에 둔감한 스테레오 정합 기법을 제안한다. 여러 가지 데이터에 대하여 실험을 한 결과, 제안하는 방법이 효과적임을 확인하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.323-330
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• 2019

Recently, as the growth of the Internet has led to a rapid increase in the consumption of multimedia such as photographs and moving images, the importance of metadata has been emphasized. In the case of existing metadata, only limited information such as GPS value or focal length according to the format is stored. However, with the development of mobile devices and multimedia acquisition devices, various sensors can be used in the devices. Therefore, this paper describes a method that can store not only the existing metadata format information at the time of multimedia acquisition but also another existing format of metadata such as information of various sensors which is the gyroscope and acceleration sensor of the device. We propose an application program that provides moving location information. The proposed method is expected to provide various applications such as image matching and effective image classification.