• 전자통신동향분석
• /
• 제35권4호
• /
• pp.65-80
• /
• 2020

In this article, we review the study trends of three-dimensional (3D) displays that can display stereoscopic images from the perspective of a display device. 3D display technology can be divided into light field, holographic, and volume displays. Light field display is a display that can reproduce the intensity and direction of light or 'ray' in each pixel. It can display stereoscopic images with less information than a holographic display and does not require coherence of the light source. Therefore, it is expected that it will be commercialized before the holographic display. Meanwhile, the holographic display creates a stereoscopic image by completely reproducing the wavefront of an image using diffraction in terms of wave characteristics of light. This technology is considered to be able to obtain the most complete stereoscopic image, and the digital holographic display using a spatial light modulator (SLM) is expected to be the ultimate stereoscopic display. However, the digital holographic display still experiences the problem of a narrow viewing angle due to the finite pixel pitch of the SLM. Therefore, various attempts have been made at solving this problem. Volumetric display is a technology that directly creates a stereoscopic image by forming a spatial pixel, which is known as a volumetric pixel, in a physical space, and has a significant advantage in that it can easily solve the problem of the viewing angle. This technology has already been tested for commercial purposes by several leading companies. In this paper, we will examine recent research trends regarding these 3D displays and near-eye display that is emerging as a significant application field of these technologies.

• 한국통신학회논문지
• /
• 제39A권11호
• /
• pp.625-636
• /
• 2014

본 논문에서는 웨이브렛 계수의 비트율-왜곡 최적화 기반 블록 부호화를 사용하는 새로운 임베디드 영상 압축방법을 제안한다. 웨이브렛 계수의 크기에 따라 셋분할 부호화나 블록분할 부호화를 수행하는 기존의 임베디드 부호화 방법들과는 달리, 제안한 방법에서는 웨이브렛 계수나 블록들을 비트율-왜곡비 기댓값에 따라 정렬함으로서 비트율-왜곡 최적화를 수행하는 동시에 비트율-왜곡비 기댓값을 이용하여 최적화된 블록분할 부호화를 수행한다. 또한 제안한 방법에서는 엔트로피 부호화를 위해 웨이브렛 계수들간에 존재하는 다양한 상관관계를 이용한다. 실험 결과는 제안한 영상 압축 방법이 기존의 임베디드 부호화 방법인 SPIHT 및 EBCOT와 비교하여 각각 0.11~1.16dB 및 -0.18~0.52dB의 PSNR 성능향상을 제공함으로써 평균적으로 우수한 성능을 제공함을 보여준다.

• 대한의용생체공학회:의공학회지
• /
• 제28권2호
• /
• pp.199-204
• /
• 2007

In digital radiography, to improve the contrast of digital radiography image, the multi-scale nonlinear amplification algorithm based on unsharp masking is one of the major image enhancement algorithms. In this paper, we used the Laplacian pyramid to decompose a digital radiography(DR) image. In our simulation, the DR image was decomposed into seven layers and the coefficients of the each layer was amplified with nonlinear function. We also imported a noise containment algorithm to limit noise amplification. To enhance the contrast of image, we proposed a new adaptive non-linear gain amplification coefficients. As a result of having applied to some clinical data, a detail visibility was improved significantly without unacceptable noise boosting. Images that acquired with the proposed adaptive non-linear gain coefficients have shown superior quality to those that applied similar gain control method and expected to be accepted in the clinical applications.

• 대한가정학회지
• /
• 제42권2호
• /
• pp.83-98
• /
• 2004

The purpose of this study was to investigate the effects of body image, body dissatisfaction, and drive for slimness, as mediated by self-esteem and depression, on eating disorder behavior according to gender The subjects of this study were 243 male and 323 female university students from Chungbuk National university in Cheonju. On the basis of previous literature, the theoretical model was specified and estimated for the adequacy of statistical fit for male and female students separately. The proposed theoretical model was supported by the data and fitted adequately. As expected, body image, body dissatisfaction, and desire for thinness had a direct effect on self-esteem for female students. However, whereas body image and body dissatisfaction directly influenced on male students' self-esteem, while desire for gaining weight had no direct effect. Eating disorder behavior in female students was predicted by body dissatisfaction, body image, and self-esteem. For male students, desire for gaining weight and self-esteem strongly predicted eating disorder behavior. The results indicate that the influence of body image, body dissatisfaction, and desire for thinness on eating disorder behavior can be mediated not by depression but by self-esteem.

• 대한원격탐사학회지
• /
• 제33권6_3호
• /
• pp.1171-1177
• /
• 2017

본 특별호는 최근 수행되고 있는 다목적실용위성 영상처리 및 활용연구에 대해서 소개하고 있으며, 사설에서는 다목적실용위성 개발 현황과 국가 위성영상 활용정책을 살펴보고 특별호에 소개된 논문의 의의에 대해서 논하였다. 지속적인 위성개발을 통해 활용 가능한 위성영상 자원과 활용정책은 체계적으로 마련되어 있는 것으로 판단된다. 따라서 본 사설에서 소개된 산림 및 도시 변화탐지, 영상보정 기술 등과 같이 다양한 자료처리 및 활용기술 개발이 지속적으로 이루어진다면 국가 위성영상의 활용 경쟁력은 더욱 강화될 것으로 기대된다.

• 항공우주산업기술동향
• /
• 제6권2호
• /
• pp.90-98
• /
• 2008

최근 고해상도위성의 개발 및 활용이 활발해지면서, 데이터 전송 및 처리를 위한 영상압축의 중요성이 대두되고 있다. 이에 발맞추어 CCSDS (Consultative Committee for Space Data Systems)에서는 고해상도위성의 영상압축권 고안인 CCSDS 122.0-B-1을 2005년 말에 발표했으며, 이는 향후 고해상도 위성의 영상압축에 널리 적용될 것으로 기대된다. 본 논문에서는 고해상도위성의 최근 동향을 알아보고, CCSDS 122.0-B-1 기반의 고해상도위성 영상압축 기술에 대해 설명하며, JPEG과 성능을 비교한 결과를 기술한다.

• 복식
• /
• 제62권3호
• /
• pp.17-28
• /
• 2012

The purpose of this study was to investigate elderly women's body image and clothing behavior. Data were collected from 305 elderly women living in Gyeongnam province from May and June of 2011. Statistical methods including frequency analysis, factor analysis, F-test, t-test, Duncan test, Cronbach's ${\alpha}$, correlation analysis and multiple regression were used for this study. The results of this study were as follows.: The body image was composed of two factors, 'physical attractiveness and interest in appearance', and 'concern about weight'. The clothing behavior was composed of the following five factors: 'social importance', 'conformity' 'individuality' 'economic efficiency' and 'clothing fashion interest'. The body image and clothing behavior according to the elderly women' demographic showed many differences. Elderly women's body image influenced their clothing behavior. These study results are highly expected to be used as valuable sources in fashion marketing plans for industries that target elderly women.

• 한국정밀공학회지
• /
• 제18권9호
• /
• pp.179-185
• /
• 2001

In this study, a visual sensor system for weld seam tracking the I-butt weld joints in GMA welding was constructed. The sensor system consists of a CCD camera, a diode laser with a cylindrical lens and a band-pass-filter to overcome the degrading of image due to spatters and arc light. In order to obtain the enhanced image, quantitative relationship between laser intensity and iris number was investigated. Throughout the repeated experiments, the shutter speed was set at 1-milisecond for minimizing the effect of spatters on the image, and therefore most of the spatter trace in the image have been found to be reduced. Region of interest was defined from the entire image and gray level of searched laser line was compared to that of weld line. The differences between these gray levels lead to spot the position of weld joint using central difference method. The results showed that, as long as weld line was within $^\pm$15$^\circ$from the longitudinal straight fine, the system constructed in this study could track the weld line successful1y. Since the processing time reduced to 0.05 sec, it is expected that the developed method could be adopted to high speed welding such as laser welding.

• 한국인터넷방송통신학회논문지
• /
• 제17권5호
• /
• pp.97-102
• /
• 2017

최근 고해상도 원격탐사 자료의 분류방안으로 컨볼루션 신경망(Convolutional Neural Networks)을 비롯한 딥 러닝 기법들이 소개되고 있다. 본 논문에서는 드론으로 촬영된 농경지 영상의 작물 분류를 위해 컨볼루션 신경망을 적용하여 가능성을 검토하였다. 농경지를 논, 고구마, 고추, 옥수수, 깻잎, 과수, 비닐하우스로 총 7가지 클래스로 나누고 수동으로 라벨링 작업을 완료했다. 컨볼루션 신경망 적용을 위해 영상 전처리와 정규화 작업을 수행하였으며 영상분류 결과 98%이상 높은 정확도를 확인할 수 있었다. 본 논문을 통해 기존 영상분류 방법들에서 딥 러닝 기반 영상분류 방법으로의 전환이 빠르게 진행될 것으로 예상되며, 그 성공 가능성을 확신할 수 있었다.

• Journal of Mechanical Science and Technology
• /
• 제19권10호
• /
• pp.1856-1863
• /
• 2005

In this study, a visual sensor system for weld seam tracking the I-butt weld joints in GMA welding was constructed. The sensor system consists of a CCD camera, a diode laser with a cylindrical lens and a band-pass-filter to overcome the degrading of image due to spatters and arc light. In order to obtain the enhanced image, quantitative relationship between laser intensity and iris opening was investigated. Throughout the repeated experiments, the shutter speed was set at 1/1000 second for minimizing the effect of spatters on the image, and therefore the image without the spatter traces could be obtained. Region of interest was defined from the entire image and gray level of the searched laser stripe was compared to that of weld line. The differences between these gray levels lead to spot the position of weld joint using central difference method. The results showed that, as long as weld line is within $\pm15^{o}$ from the longitudinal straight line, the system constructed in this study could track the weld line successfully. Since the processing time is no longer than 0.05 sec, it is expected that the developed method could be adopted to high speed welding such as laser welding.