• 한국기계가공학회지
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• 제20권10호
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• pp.38-43
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• 2021

Photocurable hydrogels are widely used as 3D printing materials in tissue engineering (e.g., scaffold fabrication) as well as optical fibers (or optical sensors) materials. Photocurable hydrogels can control optical and mechanical properties such as chemical or fabrication conditions. In previous research, we introduced a new 3D printing method to fabricate a freestanding overhanging hydrogel structure without supporting structure. This study was measured and analyzed the difference of the mechanical properties of the photocurable hydrogel according to the light intensity using a micro tensile tester. In practically, it was difficult to perform a direct tensile test on a micro (less than 1 mm) size fiber. In this study, the tensile test of the hydrogel fibers could be measured simply and repeatedly using a paper carrier.

• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.657-663
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• 2021

The main purpose of the study is to analyze the information aspects of the impact of COVID-19 on the labor market in the EU and Ukraine. In addition to studying the key parameters of changes in the labor market under the influence of COVID-19, i.e. the unemployment rate and the share of the employed population, a thorough study of gender equality, labor migration and the impact on youth made it possible to characterize the effectiveness of the policy of stabilization and restoration of the labor market in the EU and Ukraine. The results obtained form the necessary information basis for modeling labor market regulation in the event of possible subsequent disturbances, in particular under the influence of global pandemics.

• 한국도서관정보학회지
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• 제4권
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• pp.61-90
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• 1977

The historical development of books examination with utilizing science become inevitable to the machanization of library catalogues. With the advance of times, like this, a new- development of $Indention('||'&'||'$ : Kisun) must be sought for which is a kind of descriptive catalogues being used now. This paper is scheduled to grasp problems in the course of using and logical grounds of Indention which hal-e been used disordering. It must be considered that four kinds of Icdention settlement is suitable to the features of Korean letters. 1) TI-e must consider the features of Korean Language and Oriental Language writing(Japan, China). There must be a establishment of floating $Indention('||'&'||'E$ : Kisun), which are suitable for the writting style or hand writting man on the point of most of Koreans are depend upon hand witting, then books catalogues like western language, not left edge of the cards of the $Indention(B$ : Kisun) establishing, from edge to Call Number, from the last of the Call Number to First Indention(%-Bl63). First Indention(%-%%) to a space of Second $indention($\ulcorner^%)$ must be established and then, every catalogue and Indentions are distinguished surely. 2) \Then we consider the developing catalogue making in the future. It is important to establish a fixed $Indention('||'&'||'$ : Kisun) for machinization of typewriter(Korean, Mimeographing) and computer, etc ... not "Cm" unit but "Space" unit, and consider oriental letter, ne make more surplus space as a Indention, we can give anadaptablity of using machines. 3) Considering typography printing and type-setting printing by printing type, we must fit the $Indention(\ulcorner'||'&'||'$ : Kisun) as a "Cm" unit, and there must be a re-adjustment of $Indention(g$$ : Kisun) which considered the complexity of Call Number by a mass of collecting books like this, the establishment of Indention(E'||'&'||'j!: Kisun). We must not use a uilified one as a concrete conception by "Space" or "Cm" unit which has been used now but re-adjusted adaptably which can be fited as a method of making of catalogues. 4) The name of $Indcntion(J, S$ : Kisun) has becll called 7;arious methods until now, but English Indention which has been used without any concrete mexirig must be used as a ours fitable as a our mind. The above mentioned is presented as a Indention and examinational l~letilods by myself style, I wants these r i l l be helpful to the future developments of the machanization of Indention $(sf:$ Ki sun). Concrete studies must be continued in the future for development of $Indention(zj:$ : Kisun). : Kisun).

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제28권3호
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• pp.353-366
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• 2014

본 원고는 대학에서 배우는 수학적 지식이 사회가 필요로 하는 인력이 갖추어야 할 지식 및 능력과 어떤 관계가 있는지를 구체적으로 확인해 주는 대학 수학교육 논문이다. 최근 3D 프린팅의 상용화가 가속화되면서, 각 분야에 적용할 수 있는 3D 프린팅의 고급 기술개발이 중요한 과제로 떠오르고 있다. 이 과정에서, 수학적 지식의 적절한 활용은 필수적이다. 따라서 본 연구는 대학에서 배우는 수학적 지식을 바탕으로, 시간과 장소에 구애받지 않고 누구나 무료로 3D 프린팅 기술을 활용할 수 있도록 하는 클라우드 컴퓨팅 환경을 제공하고, 그를 활용하여 얻은 성과를 공유하는데 그 목적이 있다. 이러한 목적을 달성하기 위하여 한국에 맞게 자체적으로 개선한 오픈소스 소프트웨어 "Sage" 기반의 서버를 이용하여, 3D 프린팅에 필요한 STL 도면 파일을 생성하는 프로그램과 웹(Web) 도구를 개발하였다. 본 논문에서는 새롭고 혁신적인 3D 프린팅 환경을 바탕으로, 수학적 모델링의 기초지식인 미적분학과 선형대수학을 중심으로 우리가 형상화한 다양한 3D 객체(Object)들의 개발 과정을 공유하며, 이 과정을 같이 경험하는 수학전공자들이 대학에서 배운 전문 지식을 활용하여 3D 프린팅의 다양한 관련 분야로 진출하여 그 역량을 발휘 할 수 있는 비전을 제시한다. 특히 수학을 전공한 인력이 3D프린터를 보다 창의적이고 혁신적으로 활용할 수 있는 인력, 그리고 이들을 교육하는 인력으로 성장할 수 있다는 것을 확인한다.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.310-317
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• 2011

Perceptibility and acceptability are the most often used threshold units in the field of color science. The former refers to a just perceptible difference and the latter evokes a tolerable color difference. Such thresholds can be very significant to color quality control processes in the printing industry and should be defined in quality measure units. Optical density (OD) and color difference models are usually utilized as color quality measures and have been provided in a considerable number of commercial measuring devices such as spectrophotometers. However, their merits and traits are far less understood in the literature. The present study intends to evaluate performance of those color quality measures including the OD and widely known color difference models, e.g. ${\Delta}E{^*}_{ab}$, ${\Delta}E_{CMC(l:c)}$ and ${\Delta}E{^*}_{00}$. A set of psychophysical assessments were carried out in order to accumulate the perceptibility and acceptability thresholds data, and their central trend was compared with the color quality measure estimates.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 2001년도 International Conference CALS/EC KOREA
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• pp.523-532
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• 2001

Despite the social interest in eBook and its advantages, as a result of each industry using different document formats, it is difficult to exchange or share eBook contents. And this hindered the activation of eBook market. The U.S. and Japan have realized the importance of setting a standard for eBook document format and have established eBook standard with government agencies and related industries and in Korea, also, through Working Group for Standardization Committee of EBK, eBook industry standard, EBKS, was established. EBKS provides more advantages than HTML or PDF and the basic format is XML. The objective of EBKS is exact exchange of eBook content, reflection of characteristics of Korean publication environment, simplicity in creating, and convertibility with other standards. Meanwhile, in the DTD aspect, EBKS includes static document structure, extension mechanism, vertical writing, multi-column editing and reflection on the characteristics of Korean and proverbs. For exchanging style, content and style are separated using XSL-FO and XSL-FO is recommended for printing. Also, EBKS metadata is composed of do-metadata that does not use qualifier and x-metadata for extension to provide easiness in usage and ability to exchange and convert.

• Journal of Information Display
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• 제2권3호
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• pp.48-53
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• 2001

Carbon nanotube emitters, prepared by screen printing, have demonstrated a great potential towards low-cost, largearea field emission displays. Carbon nanotube paste, essential to the screen printing technology, was formulated to exhibit low threshold electric fields as well as an emission uniformity over a large area. Two different types of triode structures, normal gate and undergate, have been investigated, leading us to the optimal structure designing. These carbon nanotube FEDs demonstrated color separation and high brightness over 300 $cd/m^2$ at a video-speed operation of moving images. Our recent developments are discussed in details.

• 한국세라믹학회지
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• 제38권10호
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• pp.948-952
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• 2001

스크린 인쇄법으로 알루미나 기판 위에 PZT 후막을 제조하였으며, 공기 또는 Pb 분위기의 $750{\sim}1050^{\circ}C$에서 1시간 동안 소결하여 소결 조건이 후막의 물성에 미치는 영향을 조사하였다. 공기 중에서 $950^{\circ}C$ 이상의 온도로 소결한 PZT 후막에는 파이로클로 상이 제 2상으로 존재하고 있었으며, Pb분위기에서 소결한 PZT 후막이 공기 중에서 소결한 후막보다 치밀한 미세구조와 큰 유전상수 그리고 잘 발달된 P-E 이력특성을 보였다. $900^{\circ}C$의 Pb 분위기에서 소결한 PZT 후막은 잘 포화된 전형적인 강유전 P-E 이력곡선 모양을 보였으며, 잔류분극과 항전계가 각각 $29.8{\mu}C/cm^2$, 48.4 kV/cm이었다.

• 산업경영시스템학회지
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• 제45권2호
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• pp.48-55
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• 2022

The color image of the brand comes first and is an important visual element that leads consumers to the consumption of the product. To express more effectively what the brand wants to convey through design, the printing market is striving to print accurate colors that match the intention. In 'offset printing' mainly used in printing, colors are often printed in CMYK (Cyan, Magenta, Yellow, Key) colors. However, it is possible to print more accurate colors by making ink of the desired color instead of dotting CMYK colors. The resulting ink is called 'spot color' ink. Spot color ink is manufactured by repeating the process of mixing the existing inks. In this repetition of trial and error, the manufacturing cost of ink increases, resulting in economic loss, and environmental pollution is caused by wasted inks. In this study, a deep learning algorithm to predict printed spot colors was designed to solve this problem. The algorithm uses a single DNN (Deep Neural Network) model to predict printed spot colors based on the information of the paper and the proportions of inks to mix. More than 8,000 spot color ink data were used for learning, and all color was quantified by dividing the visible light wavelength range into 31 sections and the reflectance for each section. The proposed algorithm predicted more than 80% of spot color inks as very similar colors. The average value of the calculated difference between the actual color and the predicted color through 'Delta E' provided by CIE is 5.29. It is known that when Delta E is less than 10, it is difficult to distinguish the difference in printed color with the naked eye. The algorithm of this study has a more accurate prediction ability than previous studies, and it can be added flexibly even when new inks are added. This can be usefully used in real industrial sites, and it will reduce the attempts of the operator by checking the color of ink in a virtual environment. This will reduce the manufacturing cost of spot color inks and lead to improved working conditions for workers. In addition, it is expected to contribute to solving the environmental pollution problem by reducing unnecessarily wasted ink.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.275-276
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• 2008