• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.161-162
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• 2013

본 논문에서는 Mental ray 렌더러를 통해 렌더링 된 이미지의 색감과 사실적인 빛의 감쇠효과를 위해 사용되는 Color Management를 활용한 Linear Work Flow 작업과정을 제시하고 그 이론적인 배경을 설명하고자 한다. 디지털로 사용되는 대부분의 이미지 포맷은 모든 모니터에서 동일한 색감을 표현하기 위해 sRGB라는 표준화된 형식을 사용하고 있다. 하지만 Mental ray는 기본적으로 감마 커브가 1.0으로 이루어진 이미지를 렌더링한다. sRGB가 가지고 있는 2.2의 감마커브와 차이가 발생함에 따라 사용자가 원하는 색감을 얻어내기 어렵다. 반면에 Color Management를 활용해 렌더링 된 이미지의 감마 커브를 수정해주면 3D 소프트웨어로 사용 된 텍스쳐의 원본 색감을 렌더링 후에도 유지할 수 있다. 또한 라이팅의 감쇠(Decay)와 산란에도 영향을 주어 보다 풍부한 색감의 이미지를 얻게 된다. 본 연구에서는 Autodesk Maya의 Mental Ray를 이용해 실험을 하고 Color Management를 활용한 이미지와 그렇지 않은 이미지를 비교 분석한다. 연구의 범위는 제품 렌더링을 위한 스튜디오 라이팅 기법으로 한정하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.237-240
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• 2007

이 논문에서는 수정된 Sequential Algorithmic Schema를 이용해서 여러 장소를 이동하면서 찍은 디지털 이미지를 효율적으로 분류할 수 있는 방법을 제안한다. 제안하는 방법은 이웃 패턴들과 특징 정보의 연속성, 유사성을 가지며 들어오는 입력 패턴에 대해 기존의 모든 군집과 유사도를 비교하는 방법이 아니라 이전 군집의 정보와 유사도를 비교하여 군집에 포함시키거나 동적으로 군집을 생성하는 효율적인 군집화 방법이다. 제안한 방법은 실험을 통해서 기존의 군집화 기법에 성능 및 속도의 효율성을 증명하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1A
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• pp.1-10
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• 2012

Along with the development of coasts, islands and mountains, the demand of long-span bridges increases which, in turn, brings forth the construction of cable-supported bridges like suspension and cable-stayed bridges. There are various types of statically indeterminate structures widely applied that supported the main girder with stay cables, main cables, hanger cables with aesthetic structural appearance. As to the cable-supported bridges, the health monitoring of a bridge can be identified by measuring tension force on cable repeatedly. The tension force on cable is measured either by direct measurement of stress of cable using load cell or hydraulic jack, or by vibration method estimating tension force using cable shape and measured dynamic characteristics. In this study, a method to estimate dynamic characteristics of hanger cables by using a digital image processing is suggested. Digital images are acquired by a portable digital camcorder, which is the sensor to remotely measure dynamic responses considering convenient and economical aspects for use. A digital image correlation(DIC) technique is applied for digital image processing, and an image transform function(ITF) to correct the geometric distortion induced from the deformed images is used to estimate subpixel. And, the correction of motion of vision-based measurement system using a fixed object in an image without installing additional sensor can be enhanced the resolution of dynamic responses and modal frequencies of hanger cables.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.231-238
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• 2014

Graphical passwords using images have been developed to solve problems in text based password recognition. The basic recognition process scheme of graphical passwords is clicking certain points on the screen image in correct order. In this pre-developed method of graphical passwords the recognition will fail if the precise positions are not clicked. A new graphical password system called PassPositions is introduced in this paper. PassPositions is a new graphical password scheme which is using relative positions never used earlier graphical password schemes. PassPositions is a graphical password scheme based on universal design that everybody can use conveniently without regarding their physical conditions.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.535-544
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• 2016

This paper aims at examining the effects of sustained load and elevated temperature on the time-dependent deformation of a carbon fiber reinforced polymer (CFRP) sheets bonded to concrete as well as the pull-off strength of single-lap shear specimens after the sustained loading period using digital images. Elevated temperature during the sustained loading period resulted in increased slip of the CFRP composites, whereas increased curing time of the polymer resin prior to the sustained loading period resulted in reduced slip. Pull-off tests conducted after sustained loading period showed that the presence of sustained load resulted in increased pull-off strength and interfacial fracture energy. This beneficial effect decreased with increased creep duration. Based on analysis of digital images, results on strain distributions and fracture surfaces indicated that stress relaxation of the epoxy occurred in the 30 mm closest to the loaded end of the CFRP composites during sustained loading, which increased the pull-off strength provided the failure locus remained mostly in the concrete. For longer sustained loading duration, the failure mode of concrete-CFRP bond region can change from a cohesive failure in the concrete to an interfacial failure along the concrete/epoxy interface, which diminished part of the strength increase due to the stress relaxation of the adhesive.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.17-23
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• 2003

In this Paper. we Propose a digital watermarking scheme for digital images based on a perceptual model, the frequency masking, texture making, and luminance masking Properties of the human visual system(HVS), which have been developed in the context of image compression. We embed two types of watermark, one is pseudo random(PN) sequences, the other is a logo image. To embed the watermarks, original images are decomposed into $8\times8$ blocks, and the discrete cosine transform(DCT) is carried out for each block. Watermarks are casted in the low frequency components of DCT coefficients. The perceptual model adjusts adaptively scaling factors embedding watermarks according to the local image properties. Experimental results show that the proposed scheme presents better results than that of non-perceptual watermarking methods for image qualify without loss of robustness.

• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1601-1608
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• 2001

Digital library is the most important database system that needs information retrieval engine for natural language documents and multimedia data. This paper describes the experimental results of information retrieval engine and browser based on natural language processing. It includes lexical analysis, syntax processing, stemming, and keyword indexing for the natural language text. With the experimental database ‘Earth and Space Science’ that has lots of images and titles and their descriptive text in natural language, text-based search engine was tested. Combined with content-based image search engine, it is expected to be a multimedia information retrieval system in digital library

• Journal of Digital Convergence
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• v.18 no.8
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• pp.427-433
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• 2020

Based on the natural colors and techniques of Korean traditional Dancheong, the image from splendor and magnificence is used as a jewel in making ornaments by subjective interpretation of the researcher. The purpose of this paper is to propose the possibility of using as a jewelry design by combining the possibilities of various color expressions, the combination of solidity and luster synthetic resin by utilizing natural pigments and mono images used in Korean traditional monophonic. In this study, this study presented the possibility of accessing in the life of a modern person pursuing a lifestyle by introducing a mono image into jewelry design, and at the same time, approaching ornaments by using traditional materials of the past, modern materials, and digital production methods. We are looking for a wide variety of jewelry designs to be utilized.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.1
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• pp.96-102
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• 2009

Due to the rapid growth of the Internet, it is possible to distribute the digital content efficiently. However, the need for image data protection and secret communication technique is also on the rise because of an infringement of the copyright by malicious attackers. Shamir and Lin-Tsai proposed simple secret image encryption algorithms based on the principle of secret sharing, respectively. However, their secret sharing schemes have a serious problem which can be declined the image quality and it is possible for third party to know embed information. In this paper, we propose a new secret sharing scheme using gray code that can be increased the image quality and security. As a result of our experiment, the proposed scheme is not only shown of good image quality and but also provide enhanced security compare with Shamir and Lin-Tasi's schemes.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.313-321
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• 2022

As 5G is getting developed, people are getting interested in immersive content. Some predicts that immersive content may be implemented in real life such as holograms, which were only possible in movies. Holograms, which has been studied for a long time since Dennis Gabor published the basic theory in 1948, are constantly developing in a new direction with digital technology. It is developing from a traditional optical hologram, which is produced by recording the interference pattern of light to a computer generated hologram (CGH) and a digital hologram printer. In order to produce a hologram using a digital hologram printer, holographic element (Hogel) image must first be created using multi-view images. There are a method of directly photographing an actual image and a method of modeling an object using 3D graphic production tool and rendering the motion of a virtual camera to acquire a series of multi-view images. In this paper, we propose a new method of getting image, which is one of the visual effect, VFX, producing multi-view images using chroma key composition. We shoot on the green screen of actual object, suggest the overall workflow of composition with 3D computer graphic(CG) and explain the role of each step. We expected that it will be helpful in researching a new method of image acquisition in the future if all or part of the proposed workflow to be applied.