• 한국재료학회지
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• 제27권8호
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• pp.397-402
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• 2017

We used an etching process to control the line-width of screen printed Ag paste patterns. Ag paste was printed on anodized Al substrate to produce a high power LED. In general, Ag paste spreads or diffuses on anodized Al substrate in the process of screen printing; therefore, the line-width of the printed Ag paste pattern increases in contrast with the ideal line-width of the pattern. Smudges of Ag paste on anodized Al substrate were removed by neutral etching process without surface damage of the anodized Al substrate. Accordingly, the line-width of the printed Ag paste pattern was controlled as close as possible to the ideal line-width. When the etched Ag paste pattern was used as a seed layer for electroless Ni plating, the line width of the plated Ni film was similar to the line-width of the etched Ag paste pattern. Finally, in pattern formation by Ag paste screen printing, we found that the accuracy of the line-width of the pattern can be effectively improved by using an etching process before electroless Ni plating.

• 한국레이저가공학회지
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• 제16권4호
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• pp.12-16
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• 2013

For mass production of electronic devices, the processing of the printing roll is one of the most important key technologies for printed electronics technology. A roll of printing process, the gravure printing that is used to print the electronic device is most often used. The indirect laser processing has been used in order to produce printing roll for gravure printing. It consists of the following processing that is coating of photo polymer or black lacquer on the surface of printing roll, pattering using a laser beam and etching process. In this study, we have carried out study on the coating and etching for $25{\mu}m$ line width on the printing roll. To do this goals, a $4{\mu}m$ coating thickness and 20% average coating thickness of the coating homogeneity of variance is performed. The factors to determine the thickness and homogeneity are a viscosity of coating solution, the liquid injection, the number of injection, feed rate, rotational speed, and the like. After the laser patterning, a line width of $25{\mu}m$ or less was confirmed to be processed through etching and the chromium plating process.

• 한국농촌건축학회논문집
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• 제17권4호
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• pp.67-74
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• 2015

Due to an inability to accommodate for the rapidly increasing number of printed materials, Korean academic libraries are facing serious space shortage problems. Very few academic institutions have the funds to expand existing libraries or construct new facilities in order to accommodate the influx of printed materials. Despite not having the luxury to create new space, many establishments continue to implement the open access system. Seeing that such a system is only user friendly when used in a spacious facility, the maintenance of the open access system is unreasonable. Only few libraries consider the space efficient closed access system which helps to resolve storage space shortage. In the current state of the problem, improving the efficiency to which books are stored in existing storage areas within a library facility is the only appropriate solution. Enacting methods to improve physical space utilization within a fixed volume library facility will undoubtedly diminish the space shortage issue at hand. In this article, several space efficiency improvement approaches are discussed. Methods of book storage plan re-layout (floor, plan, ceiling, height, bookshelf design), book arrangement possibilities, and the reduction of the physical volume of reserved materials are each examined.

• 한국레이저가공학회지
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• 제15권4호
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• pp.12-15
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• 2012

On behalf of the existing semiconductor process, the electronic devices to low-cost mass production to mass print the way, the research for development of roll-to-roll printing process is actively underway. This study was performed in about the research on the manufacturing technology of the printing roll used in the printing process of electronic devices. The indirect laser imprinting technology was used to create printable roll, and after coating copper on the surface of steel and thereon after coating polymer, after removing the polymer on the surface of roll, the printable roll was made. The laser system and roll feeder system were constructed and control program was developed. We has found the optimal conditions to perform laser patterning experiments using a system developed and We can make the minimum line width of 18 ${\mu}m$.

• 산업경영시스템학회지
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• 제45권3호
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• pp.66-77
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• 2022

Digitization and automation technologies have rapidly maximized productivity and efficiency in all industries over the past few decades. Construction automation technology has either stagnated over the same period or has not kept pace with overall economic productivity. According to the research studies up to now, the output of concrete structures using coarse aggregates (8mm or more) is very limited due to the limitations of equipment and materials. In this study, information on the development process of 3DCP equipment that can print concrete structures with the printing width (100 mm or more) and printing thickness (30 mm or more) using a 3DCP material mixed with coarse aggregate (8 mm or more) is provided. To verify the performance of the developed 3DCP equipment, experimental data are provided on output variables, the number of layers, and the inter-layer printing time interval. The evaluation and verification data of various mechanical properties (compressive and splitting tensile strength) of printed materials using coarse aggregates are provided.

• 한국재료학회지
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• 제33권7호
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• pp.285-294
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• 2023

Porous ceramics are used in various industrial applications based on their physical properties, including isolation, storage, and thermal barrier properties. However, traditional manufacturing environments require additional steps to control artificial pores and limit deformities, because they rely on limited molding methods. To overcome this drawback, many studies have recently focused on fabricating porous structures using additive manufacturing techniques. In particular, the binder jet technology enables high porosity and various types of designs, and avoids the limitations of existing manufacturing processes. In this study, we investigated process optimization for manufacturing porous ceramic filters using the binder jet technology. In binder jet technology, the flowability of the powder used as the base material is an important factor, as well as compatibility with the binder in the process and for the final print. Flow agents and secondary binders were used to optimize the flowability and compatibility of the powders. In addition, the effects of the amount of added glass frit, and changes in sintering temperature on the microstructure, porosity and mechanical properties of the final printed product were investigated.

• 정보관리학회지
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• 제21권2호
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• pp.45-67
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• 2004

본 연구는 인쇄잡지 중심의 소장 패러다임 대 전자잡지 위주의 접근 패러다임이 대립하는 상황에서 대학도서관의 하이브리드형 학술지 수집정책의 이론적 토대가 되는 평가요소를 분석하여 한국적 실정을 고려한 외국 학술지의 평가모형 개발에 필요한 기초자료를 마련하는데 그 목적이 있다. 구체적으로 질문지법을 통하여 학술지 수집규모 상위 40개 대학도서관의 외국학술지 선정과정에서 예비평가지표(인쇄형 27개, 전자형 37개)의 적용도를 조사하고, 그 데이터를 다양한 통계적기법으로 분석하였다. 인쇄학술지 평가지표의 요인별 상대적 중요성은 응답 평균값으로 산출하였는데 그 결과는 학과당 구독종수, 이용도, 선정권한, 전자학술지 구독조건, ISI 영향지수, 국제성과 지명도, 구독가격, ILL/DDS 수장공간 순으로 나타났다. 한편, 전자학술지는 구독가격, 접근성, 전자학술지 구독조건, 컨소시엄, 선정권한, 접근확장성, 학과당 구독종수, 대학의 학문적 특성, ISI 영향지수, ILL/DDS 국제성과 지명도 순으로 나타났다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3131-3137
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• 2013

Background: Visual inspection of cervix with acetic acid (VIA) is offered at 252 centers in 64 districts of Bangladesh. VIA+ve women are managed at colposcopy clinics of Bangabandhu Sheikh Mujib Medical University (BSMMU) and 14 Medical College Hospitals (MCHs). This research work has been supported by 'UICC Cancer Prevention Campaign' programme. Objectives: This study explored the role of print materials and electronic media to improve cervical cancer screening in the present socio-cultural context of Bangladesh. Methods: This study was performed from January to August 2011 at two upazilas of Bangladesh (Singair with screening facility and Sonargaon without screening facility). Data were collected by focus group discussion (FGD) with women, husbands and community people before and after intervention. Information on cervical cancer screening and VIA camps was disseminated using advertisement through local cable line of the television, microphone announcement, service providers and leaflet throughout the week prior to a VIA camp. Three-day VIA camps were organized at the upazila health complex (UHC) of both upazilas. Quantitative data was gathered from women at the camps on source of information on VIA and the best method of awareness creation. Results: The population was aware of "cancer" and a notable number knew about cervical cancer. Baseline awareness on prevention and VIA was low and it was negligible where screening services were unavailable. Awareness was increased fourfold in both upazilas after interventions and half of the women and the majority of the community people became aware of screening and available facilities. Cable line advertisement (25.5%), microphone announcement (21.4%), and discussion sessions (20.4%) were effective for awareness creation on VIA. Television was mentioned as the best method (37.4%) of awareness creation. Conclusion: Television should be used for nation-wide awareness creation. For local awareness creation, cable line advertisement, microphone announcements and health education at Uthan Baithaks/ EPI sessions can easily be adopted by the government.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.585-586
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• 2006

In this paper, we present a design, analysis, fabrication and performance test of the novel DoD metal-jet system for application to the high-density and high-temperature-melting materials. Based on the theoretical analysis, we design the metal-jet print head system and fabricate the metal-jet system, which can eject the droplet of lead-free metal solder in the high-temperature. In the experimental test, we set up the test apparatus for visualization of the droplet ejection and measure the Ejected droplet volume and velocity. As a result, the diameter, volume and the velocity of the ejected droplet are about $65-70{\mu}m$, 145-180 pl and 4m/sec. We also fabricate vertical and inclined 3D micro column structures using the present molten metal inkjet system. The measured geometries of the micro column structures are about height of $2,100{\mu}m$, diameter of $200{\mu}m$ and aspect ratio of 10.5 for vertical micro column and $1,400{\mu}m$ of height and $150{\mu}m$ of diameter for $65^{\circ}$-inclined micro column, respectively.

• 한국재료학회지
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• 제10권2호
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• pp.171-174
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• 2000

본 연구에서는 실리콘 wafer위에 sputtering방법으로 진공증착된 CoNbZr 비정질 박막을 Nd:YAG 레이저로 식각하기 위한 실험을 했는데, 금속의 경우 표면에서 빛의 반사율이 매우 크기 때문에 파장이 $1.06{\mu\textrm{m}}$인 Nd:YAG 레이저의 에너지를 흡수하는 것이 매우 어려우므로 식각이 거의 이루어지지 않았다. 그래서 이러한 문제를 해결하기 위한 새로운 시도로서 본 연구에서는 빛의 흡수율이 좋은 검은색의 polymer막을 금속박막의 표면에 도포하고 이 polymer막 위에 레이저를 조사해서 금속박막의 식각하는 실험을 실시하였다. 기존의 방법으로는 laser power가 332W나 되는데도 식각이 거의 일어나지 않았지만 본 연구의 방법을 이용했을 때는 laser power가 114W로 1/3정도 밖에 안 되는데도 레이저 식각이 비교적 양호하게 이루어졌다. 이는 검은색의 polymer층이 Nd:YAG 레이저 에너지의 흡수 및 전달 층의 역할을 하기 때문인 것으로 생각된다.