• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.115-118
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• 2001

최근 많은 분야에서 사용되고 있는 RF(Radio Frequency)를 이용하여 원거리에서 무선으로 소형전광판에 문자 데이터를 보낼 수 있도록 하여 손쉽게 문구를 바꿀 수 있는 광고용 전광판을 구현하였다. 구현된 전광판은 소프트웨어 부분과 하드웨어 부분으로 나누어서 살펴보면, 사용자로부터 전광판에 표시하려는 문장을 IBM PC에 입력 받아서 전광판으로 송신하도록 하는 윈도우용 프로그램과 전광판에 표시될 데이터를 무선으로 수신 받아서 전광판에 표시하도록 해주는 프로그램이 전광판에 사용되는 소프트웨어가 되겠다. IBM PC에서 전광판으로 데이터를 보내고 전광판에서 그 데이터를 받기 위해서 RF모듈을 사용하였고, 전광판에 수신된 데이터를 전광판에 표시하기 위해서 마이크로컨트롤러를 사용하였다. 구현된 전광판은 16×16크기의 도트 매트릭스를 각각 12개씩 사용하여 문자열 2줄을 표시할 수 있도록 제작하였다. 한 문자를 표현하는데 한 개의 도트매트릭스가 사용되므로 표시될 문자는 16×16도트에 맞는 문자 폰트를 가지며, 문자 폰트를 나타내는 방법은 완성형과 조합형이 있으나 프로그램을 간단히 하기 위해서 완성형을 사용하였다.

• The Magazine of the IEIE
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• v.18 no.11
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• pp.1-10
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• 1991

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.377-381
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• 2011

The purpose of this study is an assessment between the measured value of the nanoDot dosimeter and the calculated value of Non Dosimeter Dosimetry-Method(NDD-M) for entrance surface dose in general radiography. Measurement and calculation of the entrance surface doses were performed for head(AP), abdomen(AP), pelvis(AP), thoracic spine(AP) and lumbar spine(AP). As a result, the relative ratios of the measured value to the calculated value were acquired 1.5-2.1 for each region. Reproducibility acquired 0.035 as a coefficient of variation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.165-171
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• 2017

Reading Pen is used mostly in educational purpose, yet its possibility is great as an input device for various IT devices. Reading Pen recognizes tiny dot patterns printed in papers, converts the patterns to corresponding codes, and plays audio contents that match the codes. Recognizing dot patterns and converting to the codes are the main function of Reading Pens, on which we focus and propose a novel algorithm. Such technology is never open to public and this paper is the first open attempt in this area. We test the algorithm and obtain 85% recognition ratio.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.11a
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• pp.197-198
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• 2016

최근 RGB LED 조명은 다양한 장점으로 이를 활용한 연구가 진행되고 있으며 단순 조명이 아닌 정보전달 및 공간연출의 디자인적 요소의 역할을 이행하기도 한다. RGB의 혼합으로 다양한 색상이 표현 가능한 LED를 사용하여 개별적으로 LED를 제어해 여러 가지 색상 및 모양이 표현 가능한 LED 도트 매트릭스를 제작하였으며, 이를 활용해 다양한 콘텐츠를 출력하고자 한다. 다양한 모양의 콘텐츠에선 개별적으로 LED를 제어하고, 그 외의 콘텐츠에선 원하는 LED를 그룹지어 제어한다. 본 논문에서 제작한 LED 도트 매트릭스는 많은 정보를 전달 할 수 있으며, 다양한 콘텐츠 제공으로 인한 상업화 및 효율성의 확대를 꾀할 수 있다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.2 s.308
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• pp.40-47
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• 2006

This paper proposes a multitoning method using threshold modulation of MJBNM(Modified Jointly Blue Noise Mask) for banding artifacts reduction. As banding artifacts in multitoning appear as uniform dot distributions around the intermediate output levels, such multitone output results in discontinuity and visually unpleasing patterns in smooth transition regions. Therefore, to reduce these banding artifacts, the proposed method rearranges the dot distribution by introducing pixels in the neighborhood of output levels that occurs banding artifacts. First of all principal cause of banding artifacts are analyzed using mathematical description. Based on this analytical result, a threshold modulation technique of MJBNM which takes account of chrominance error and correlation between channels is applied. The original threshold range of MJBNM is first scaled linearly sot that the minimum and maximum of the scaled range include two pixel more than adjacent two output levels that cover an input value. In an input value is inside the vicinity of any intermediate output levels produce banding artifacts, the output is set to one of neighboring output levels based on the pointwise comparison result according to threshold modulation parameter that determines the dot density and distribution. In this case, adjacent pixels are introduced at the position where the scaled threshold values are located between two output levels and the minimum and maximum threshold values. Otherwise, a conventional multitoning method is applied. As a result, the proposed method effectively decreased the appearance of banding artifacts around the intermediate output levels. To evaluate the quality of the multitone result, HVS-WRMSE according to gray level for gray ramp image and S-CIELAB color difference for color ramp image are compared with other methods.

• Korean Journal of Optics and Photonics
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• v.33 no.6
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• pp.267-274
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• 2022

In this paper, we report the design and fabrication of binary diffractive optical elements (DOEs) for random-dot-pattern projection for Schlieren imaging. We selected the binary phase level and a pitch of 10 ㎛ for the DOE, based on cost effectiveness and ease of manufacture. We designed the binary DOE using an iterative Fourier-transform algorithm with binary phase optimization. During initial optimization, we applied a computer-generated pseudorandom dot pattern of uniform intensity as a target pattern, and found significant intensity nonuniformity across the field. Based on the evaluation of the initial optimization, we weighted the target random dot pattern with Gaussian profiles to improve the intensity uniformity, resulting in the improvement of uniformity from 52.7% to 90.8%. We verified the design performance by fabricating the designed binary DOE and a beam projector, to which the same was applied. The verification confirmed that the projector produced over 10,000 random dot patterns over 430 mm × 430 mm at a distance of 5 meters, as designed, but had a slightly less uniformity of 84.5%. The fabrication errors of the DOE, mainly edge blurring and spacing errors, were strong possibilities for the difference.

• The monthly packaging world
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• s.336
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• pp.80-93
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• 2021

• Fashion & Textile Research Journal
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• v.20 no.5
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• pp.592-599
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• 2018

The purpose of this study is to investigate consumer needs, image sensibility and preference of bedding fabric according to size and spacing of dot pattern. 18 kinds of dot pattern fabrics were designed with different diameters(6, 8, 10cm) and distances(4, 7, 10cm) in regular arrangement of diamond figure. The subjects were 162 male and female university students. The data were analyzed by SPSS 24.0. Fabrics were assessed subjectively using a 5-point scale 17 consumer needs and 33 sensory descriptors. The most consumer's needs for bedding fabric was shown to be functionality of bedding including hygiene, touch, warmth, ease of washing and management, air permeability, and hygroscopicity. The other parameters of consumer's needs were shown to be physical property and design parameter. The results of analysis of the dimension of image sensibility for fabrics with different size and spacing of dots are derived from six factors including joyfulness, coziness, uniqueness, charm, femininity, and complexity. As a result of analysis of preference with fabric kinds, there was a significant difference in preference with fabrics. The preferred fabrics were characterized by the pattern and the base fabric being striking three-dimensionally with 1/3 twill and 3/1 twill fabric. Sensory descriptors related to joyful image and unique image were analyzed as evaluation terms that can distinguish the preferences of fabrics. Correlation analysis showed the fabrics are preferred as the difference in luminance and reflectance between the base and pattern of the fabric become larger and the spacing of patterns become closer.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.79-83
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• 2018

In this paper, we measured and analyzed the dose correction factor, absorbed dose linearity, peak voltage X-ray response, angular dependence. Exposure dose correction factor, absorbed dose linearity, and peak voltage linearity using the medical X-ray generator were all in accordance with IEC-62387-1 (2007). The reference to the dosimetry direction at 0, 30, and 60 degrees relative to baseline radiation exposure was -29% (${\pm}30^{\circ}$) and + 67% (${\pm}60^{\circ}$). The values measured at $30^{\circ}$ were -8% lower than the standard and -18% lower than the standard at $60^{\circ}$. Therefore, the effect of direction should be corrected when using OSL dot dosimeter.