• Korean Journal of Optics and Photonics
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• v.15 no.3
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• pp.200-213
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• 2004

The realization of partially coherent Gaussian Schell-model beams with isotropic cross section and anisotropic degree of coherence function is investigated theoretically. An optical system is devised to transform diffused light generated by passing the Gaussian beam of the He-Ne laser thorough a rotating holographic diffuser to the partially coherent Gaussian Schell-model beam with isotropic cross section and anisotropic degree of coherence function. Analytic design equations are formulated and design examples are presented.

• Korean Journal of Optics and Photonics
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• v.35 no.1
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• pp.18-23
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• 2024

In exhibition spaces such as art museums, lighting should primarily illuminate the walls where exhibits are displayed rather than the floor. Commonly used LED lighting consists of an LED and a diffusion plate that closely resembles a Lambertian light source with uniform light distribution at every angle. This type of illumination focuses on the floor surface where normal incidence occurs. Consequently, this general illumination method is not well-suited for effectively lighting the wall surface. Specifically, to illuminate a wall, it is necessary to increase the light intensity in areas with a large incident angle in the light distribution. In response to this issue, our study proposes an illumination system that uses an ultra wide converter to adjust the divergence angle from the light source to 180 degrees.

• KAPE Magazine
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• s.176
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• pp.4-5
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• 2011

정부가 구제역 발생 이후의 대한민국 축산업 재건을 위해 대대적인 리모델링 착수에 들어갔다. 방향은 ${\blacktriangle}$방역메뉴얼 개편 ${\blacktriangle}$조직정비 ${\blacktriangle}$축산업 선진화 등 크게 3가지이다. 이와 함께 정부는 지난 3월 24일부로 구제역이 진정돼 안정적인 통제가 가능하다는 판단에 따라 구제역 경보단계를 '심각'에서 '경계'로 한 단계 낮추기로 했다. 구제역 발생에 따른 위기 경보 단계는 '관심(주변국 발생)${\rightarrow}$주의(국내 발생)${\rightarrow}$경계(확산)${\rightarrow}$심각(3개 시 도)' 등 총 4단계로 구성돼 있다.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.469-470
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• 2007

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• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.49-50
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• 2001

저층트롤이나 기선저인망 등에서 발생되는 뻘물(Sand cloud)은 시각자극에 의한 어류의 구집과 어구 시인도에 크게 영향을 미치게 된다. 여기서는 저층트롤의 전개판과 발줄등에 의한 뻘물의 발생범위 및 확산 정도를 기하학적인 형상으로 수치모델링하고, 이를 기초로 뻘물의 시각적 형상을 입자발생모델에 따라 그래픽 애니매이션 하였다. (중략)

• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.306-310
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• 2007

Characteristics of GDL (Gas Diffusion Layer) mainly determine the gas diffusion and water removal in a cell, thereby changing the performance and affecting durability of PEFC. To optimize the water management and understand the two phase flow in a GDL, it is important to study the behaviors of GDL micro structure under the real operating condition. In the clamped condition of cell, the GDL beneath the rib is more compressed than beneath the channel. Many researches on physical, electrochemical, mechanical behaviors of gas diffusion layer has been conducted. However, changes in surface properties under clamped condition have rarely studied. In present study, the morphology of broken connections of carbon fibers and detachment of PTFE coatings on the fibers were shown from the microscopic observations. In addition, changes in wetting properties of GDL by compression were investigated by using XPS and liquid uptake methods. The hydrophobic characteristics of GDL surface beneath the rib of the flow field plate are changed due to the deformation of micro structure.

• Journal of IKEEE
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• v.19 no.2
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• pp.168-175
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• 2015

In this paper, we propose FPGA design technique for rotating LED display device which is capable of displaying videos with the use of the afterimage effect. The proposed technique is made up of image data correction process based on inverse gamma correction and error diffusion, block interleaving process, and data serial output process. The data correction process based on inverse gamma correction and error diffusion is an image data correction step in which image data received are corrected by inverse gamma correction process to convert the data into linear brightness characteristics, and by error diffusion process to reduce the brightness reduction phenomenon in low-gray-level which is caused by inverse gamma correction. In the block interleaving process, the data of the frames entered transversely are first saved in accordance with entrance order, and then only the longitudinal image data are read. The data serial output process is applied to convert the parallel data in a rotating location into serial data and send them to LED Driver IC, in order to send data which will be displayed on high-speedy rotating LED Bar. To evaluate the accuracy of the proposed FPGA design technique, this paper used XC6SLX45-FG484, a Spartan 6 family of Xilinx, as FPGA, and ISE 14.5 as a design tool. According to the evaluation analysis, it was found that goal values were consistent with simulation values in terms of accurate operation of inverse gamma and error diffusion correction, block interleaving operation, and serialized operation of image data.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.656-663
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• 2007

최근 인터넷 공간에서 사용자가 직접 만들어 내는 컨텐츠, 즉 UCC (user created contents, 이하 UCC)에 대한 관심이 그 어느 때보다 증가하고 있다. UCC란 기존의 온라인 컨텐츠 제공업자와 달리 일반 사용자에 의해 만들어져 게시판과 같은 도구를 사용하여 온라인 상에 존재하였다. 그런데 UCC 가 최근 들어 더욱 관심을 받고 있는 이유에는 사용자들이 직접 컨텐츠를 만들어 개제하는 것이 용이하도록 변화된 환경의 조성 및 컨텐츠 제작을 쉽게 할 수 있는 저작도구가 지속적으로 만들어지고 확산되었기 때문이다. 결과적으로 사용자 측면에서는 다른 사람들과 소통하는 통로가 확대되었고, 사업자 측면에서는 보다 컨텐츠를 풍부하게 확보할 수 있는 환경이 열린 것이다. 본 연구는 구비문학의 이론을 통하여 UCC의 활성화에 영향을 미치는 요소를 탐색적으로 살펴보는 것을 목적으로 한다. 구비 문학은 텍스트를 향유하는 사람들 사이에서 공유되는 이야기로서 그 생산 환경의 매커니즘과 텍스트의 발전 양상이 UCC와 매우 유사하다. 따라서 본 연구에서는 자료의 분석과 이론적 모형의 수립 과정 전반에 있어 구비 문학의 이론과 접근 방법을 사용하였다. UCC가 매우 활발하게 생산되는 주제를 선정하여, 그 주제에 해당하는 커뮤니티의 특성, 사용자들 간의 관계, 사용자 정책 등 차이가 있는 세 온라인 커뮤니티를 선정하였다. 선정된 온라인 커뮤니티의 게시판의 포스트와 댓글을 프로그램을 통하여 수집하고 분석하였으며, 그 분석된 데이터를 바탕으로 사용자를 선정하여 심층 인터뷰를 진행하였다. 심층 인터뷰 데이터는 근거이론은 이용하여 분석하였다. 본 연구의 결과는 UCC 확산이라는 새로운 인터넷 패러다임 속에서 이를 구비 문학의 이론으로 분석했다는 점에서 학문적 의의가 있다. 또한 성격이 다른 세 개의 사이트에서의 UCC를 비교함으로써 UCC를 기반으로 한 사이트 설계의 가이드 라인이 될 수 있는 실용적 의의를 가진다.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.709-719
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• 2016

This study reviews the so-called 'format-export' of Korean TV entertainment programs to China, and ahalyze its effect on the spread of Hallyu in China. Format export has developed as an alternative for the export of Korean TV programs when the Chinese government restrict the broadcasting of foreign TV programs. In so doing, the study conducted surveys about the format-exported programs in Shanghai and Zhengzhou with the sample of 381 university students. The survey shows that the popularity of entertainment programs is so high as to compete with the popularity of K-pop. Respondents in Zhengzhou tend to watch format-exported programs first and then try to watch original Korean programs, while respondents in Shanghai are more likely to watch original Korean programs. This results suggest that format-export can help the spread of Hallyu in the inland local cities in China.

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.401-409
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• 2007

A new sheet of back light unit(BLU) to reduce the number of sheets and enhance the optical performances of direct back light unit(BLU) in a liquid crystal display is proposed and designed. In order to improve the straightness and spatial uniformity of brightness of the BLU, we design the new sheet with linear arrays of complicated bar prism by using the fusion of cylindrical lens and bar prism. Then, we investigate and analyze various optical performances of a BLU including the new sheet through an illumination optical system design program. From these results, we determine the optimum geometrical structure of the sheet. Under the optimum condition, the luminance efficiency and spatial uniformity of luminance of the BLU are 53.5% and 83.5% respectively. And the vertical and horizontal widths of the angular luminance distribution are $90^{\circ}$ and $112.5^{\circ}$ respectively. Finally we have fabricated a new BLU sheet according to this design shape by using an ordinary resins.