• Journal of radiological science and technology
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• v.39 no.4
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• pp.631-636
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• 2016

Hitherto, spatial resolution has commonly been evaluated by test patterns or phantoms built on some specific distances (from close to far) between two objects (or double targets). This evaluation method's shortcoming is that resolution is restricted to target distances of phantoms made for test. Therefore, in order to solve the problem, this study proposes and verifies a new method to efficiently test spatial resolution with a single target. For the research I used PSF and JND to propose an idea to measure spatial resolution. After that, I made experiments by commonly used phantoms to verify my new evaluation hypothesis inferred from the above method. To analyse the hypothesis, I used LabVIEW program and got a line pixel from digital image. The result was identical to my spatial-resolution hypothesis inferred from a single target. The findings of the experiment proves only a single target can be enough to relatively evaluate spatial resolution on a digital image. In other words, the limit of the traditional spatial-resolution evaluation method, based on double targets, can be overcome by my new evaluation one using a single target.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.6
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• pp.133-141
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• 2008

As interactive multimedia have come into wide use, user interfaces such as remote controllers or classical computer mice have several limitations that cause inconvenience. We propose a vision-based pointing device to resolve this problem. We analyzed the moving image from the camera which is embedded in the pointing device and estimate the movement of the device. The pose of the cursor can be determined from this result. To process in the real time, we used the low resolution of $288{\times}208$ pixel camera and comer points of the screen were tracked using local optical flow method. The distance from screen and device was calculated from the size of screen in the image. The proposed device has simple configurations, low cost, easy use, and intuitive handhold operation like traditional mice. Moreover it shows reliable performance even in the dark condition.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.220-220
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• 2021

2020년 장마는 6월 중순부터 8월 중순까지 전국적으로 평균 687 mm의 강수가 내려, 1973년 이후 역대 2위 강수량을 기록하였으며, 연이은 태풍으로 큰 인명 및 재산 피해가 발생하였다. 특히, 섬진강 및 한탄천 등에서 계획홍수위를 초과하는 홍수로 인해 상당수의 제방이 월류로 인해 붕괴된 것으로 나타났다. 따라서, 향후 기후변화에 따른 연평균 강수량이 증가할 것으로 전망되는 가운데 집중호우로 인한 제방 붕괴 피해를 최소화하기 위한 고도화된 기술 개발을 통한 선제적 재발 방지대책이 필요한 시점이다. 한국건설기술연구원은 바이오폴리머라는 새로운 친환경 신소재를 이용하여 제방의 안정성 평가 기술 개발 연구를 수행하고 있다. 이에 안동하천연구센터에서는 실규모에 준하는 제방모형(높이 3 m, 사면경사 1:2, 길이 10 m 이상)을 제작하고, 제방 표면에 바이오폴리머 신소재를 처리하여 전방 월류 흐름 유도에 따른 실규모 제방붕괴실험을 수행하였다. 또한, 신소재 보강 및 무보강 조건에 따른 영상분석 기반 붕괴지연효과를 정량적으로 분석하여 신소재의 성능을 평가하였다. 하지만, 기존에 수행된 실험은 댐 붕괴 흐름과 같이 홍수파가 발생하여 제내지로 퍼져 나가는 형태로 진행되어, 보강공법의 검증에 있어 실제 하천에서 발생하는 횡월류 흐름을 재현하지 못한다는 한계를 가지고 있다. 본 연구에서는 횡월류 흐름(0.6 m³/s 이상)을 발생시켜 수리실험에 따른 축척효과(scale effect)를 최소화하고, 현장에 대한 충분한 자연성을 재현하는 것을 목표로 하여 실험을 수행하였다. 실험 조건은 1) 신소재가 처리된 식생 제방, 2) 신소재가 처리되지 않은 식생 제방으로 각각의 조건에 따른 횡월류 흐름 및 제방 붕괴를 유도하여 영상분석 기법(이미지 픽셀분석 및 3D 포인트 클라우드 모델링)을 통한 침식 저항에 관한 분석결과를 제시하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.165-170
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• 2012

Purpose: The aim of this study was to measure and evaluate changes of visual responses in viewing a 2D and 3D (three-dimensional) image. Methods: The subjects were 44 college students aged 19 to 25 years with normal binocular vision. The visual responses measured were CA/C (convergence accommodation/convergence) ratio, convergence-induced PD(interpupillary distance), accommodative responses, perceived distance in viewing a 3D image. Results: Convergence and accommodative responses in viewing the 3D image were significantly larger (p<0.05) than in 2D. A moderate positive correction was found between CA/C ratio and accommodative response (r = 0.477, p = 0.001). It was indicated that smaller PD had larger depth perception. Convergence in viewing the 3D image was significantly larger (p<0.05) than that at cognitive distance. Conclusions: The visual fatigue may be more intense in larger CA/C ratio and smaller PD when viewing 3D images.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.185-194
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• 2020

This study aims to figure out how the brand experience design elements works in the Shortform video-based branding through case analysis. The sense, feel, think, act, relate experience of Shortform video brand are provided through the implementation of specific experience design elements in the process of the creators expressing personality through social media channels and communicating and interacting with consumers. As a result, LIZIQI's food videos provided a brand identity as an 'Eastern gourmet' to consumers through the audiovisual stimulation of food in video, the cognitive reinforcement which is combined of identities and products, and the behavioral participation by web sites·electronic media. In addition, a strong brand relationship was established by sharing emotional ties using human factors and responsibility through co-branding. This can be extended to various Shortform video contents-based branding cases, and it will suggest a useful approach to the brand building strategy through strategic brand experience design elements.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.1
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• pp.21-28
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• 2005

In this paper, we studied resolution to the FBP(Filtered Back-Propagation) tomographic image reconstruction algorithms. In order to analyze the resolution to the tomographic images, we derived ambiguity function to this algorithm which can be reconstructed from the improved FBP image reconstruction algorithm by using fixed coordinate system practically. Through simulation using this function, we determined the lateral and depth resolution quantitively and then analyzed respectively. Simulation results show that the lateral and depth resolution to the improved FBP image reconstruction algerian was determined $0.27\lambda\;and\;0.70\lambda$ at the 3dB, and also $0.89\lambda\;and\;0.96\lambda$ at the 6dB respectively. This results proved that improved FBP reconstruction algorithms for diffraction tomography of incident planar wave is useful to developed the tomographic image system, analyze the resolution to the tomographic images, we derived ambiguity function to this algerian which can be reconstructed from the improved FBP image reconstruction algorithm by using fixed coordinate system.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.1
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• pp.1-7
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• 2012

This paper presents a method for 3D image construction using the hybrid (color and depth) camera system, in which the drawbacks of each camera can be compensated for. Prior to an image generation, intrinsic parameters and extrinsic parameters of each camera are extracted through experiments. The geometry between two cameras is established with theses parameters so as to match the color and depth images. After the preprocessing step, the relation between depth information and distance is derived experimentally as a simple linear function, and 3D image is constructed by coordinate transformations of the matched images. The present scheme has been realized using the Microsoft hybrid camera system named Kinect, and experimental results of 3D image and the distance measurements are given to evaluate the method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3C
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• pp.296-306
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• 2003

In this paper, algorithm for non-iterative decoding method is proposed and fractal image decoder based on non-iterative fractal decoding algorithm used general purpose digital signal processors is designed and implemented. The algorithm is showed that the attractor image can be obtained analytically whe n the image is encoded using the fractal algorithm proposed by Monro and Dudbridge, in which the corresponding domain block for a range block is fifed. Using the analytical formulas, we can obtain the attractor image without iteration procedure. And we get general formulas of obtained analytical formulas. Computer simulation results for various test images show that we can increase the image decoding speed by more than five times when we use the analytical formulas compared to the previous iteration methods. The fractal image decoder contains two ADSP2181's and perform image decoding by three stage pipeline structure. The performance tests of the implemented decoder is elapsed 31.2ms/frame decoding speed for QCIF data when all the frames are decoded. The results enable us to process the real-time fractal decoding over 30 frames/sec.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.321-325
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• 2003

The technology for the multi-dimensional terrain perspective view can be used as an important factors in planning and designing for the various construction projects. In this study, the stereo image perspective view has been generated for the multi-dimension analysis by combining useful digital map and remotely sensed satellite images. In the course of experimenting with the multi-dimensional topography generated by the combination of the front-projected image by the precise GCP and DEM from the contour line, the technology has been developed to offer the multi-dimensional access to the potential construction sites from the nearby main roads. This stereo image bird's eye view has made it possible to make multi-dimensional analysis on the terrain, which provides real time virtual access to the designated construction sites and will be a versatile application for development planning and construction projects.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.3
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• pp.1-8
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• 2002

The technology for the three-dimensional terrain perspective view can be used as an important factor in planning and designing for the various construction projects. In this study, the stereo image perspective view has been generated for the multi-dimension analysis by combining useful digital map and remotely sensed satellite images. In the course of experimenting with the three-dimensional topography generated by the combination of the orthopimage by the precise GCP and DEM from the contour line, the technology has been developed to offer the multi-dimensional access to the potential construction sites from the nearby main roads. This stereo image bird's eye view has made it possible to make multi-dimensional analysis on the terrain, which provides real-time virtual access to the designated construction sites and will be a versatile application for development planning and construction projects.