• Title/Summary/Keyword: Printing concrete

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Strength Characteristics of 3D Printed Composite Materials According to Lamination Patterns (적층 패턴에 따른 3D 프린팅 복합재료의 강도특성)

  • Seo, Eun-A;Lee, Ho-Jae;Yang, Keun-Hyeok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.6
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    • pp.193-198
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    • 2021
  • In this study, the rheological characteristics and of 3D printing composite materials and the compressive strength characteristics according to the lamination patterns were evaluated. As a result of rheology test, rapid material change was observed after 60 minutes of extrusion, yielding stress 1.4 times higher than immediately after mixing, and plastic viscosity was 14.94-25.62% lower. The compressive strength of the specimens manufactured in the mold and the laminated specimens were compared, and the lamination pattern of the laminated specimens were 0°, 45°, and 90° as variables. The compressive strength of the mold casting specimen and the laminated specimen from 1 to 28 days of age showed similar performance regardless of the lamination pattern. In particular, at the age of 28 days, the modulus of elasticity, maximum compressive strength, and strain at maximum stress of all specimens were almost the same. In order to analyze the interface of the laminated specimens, X-ray CT analysis of the specimen whose compressive strength were measured was performed. Through CT analysis, it was confirmed that cracks did not occur at the lamination interface, which can be judged that the interface in the laminated specimen behaved in an integrated manner.

The Reminding Words Evaluation Method for Icon Design (연상단어 평가를 통한 아이콘 디자인 연구)

  • Ha, Kwang Soo
    • The Journal of the Korea Contents Association
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    • v.14 no.10
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    • pp.64-72
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    • 2014
  • As the importance of interface became emphasized recently, function of icon as an element that helps operation and formative function as an aesthetic element are becoming emphasized. Specially, various research methodologies for measuring the understanding degree of users are being attempted in functional aspect, however, they are facing limitations as user evaluation method of quantitative investigation for statistical analysis became overly dependent on the consent from majority. To overcome such limitation, a methodology of measuring sensibility as aesthetic impression or individuality based on the system of emotion or system of understanding of users and designing icon based on the measurement is being attempted continuously. Therefore, this study suggested an evaluation method using reminding words and conducted an empirical study to apply results on the icon design by applying the evaluation method on icon design of printing products to measure the user sensibility and understanding level. Through this process, this study intended to research summaries on the design evaluation method which based on the evaluation of user sensibility and understanding level and to debate effective design methodologies through the process of applying these summaries on the project. The intention was to progress discussion from practical application perspectives apart from the textbook type discussion by applying a research methodology through concrete cases. This study objectified sensibility and understanding level of users in the icon design aspect, suggested a methodology that can be applied on the design, and it is expected to be used when progressing the icon and GUI design.

The narrative and theme of (<연정 구운몽>의 서사 전개 및 주제 구현 양상과 그 의미)

  • Eom, Tae-ung
    • (The)Study of the Eastern Classic
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    • no.68
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    • pp.99-144
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    • 2017
  • This paper focused on the narrative and theme of which is one of the different versions of when published in 1910's as a modern printing. Generally researchers regarded different version as a means of research for finding best version. But this paper aimed at the characteristics of different version . This version kept in mind for play(drama), so we could easily find the purpose of change for scenario. 'Yeon-jeong' in is 연정(演訂) in Korean words in Chinese characters. It is sure that this word means that the text considered play(drama). The narrative of also told us that this old novel aimed at the stage. Tendencies are classified four features, first, abundant situation description, second, frequent direct conversation, third, concrete description about direct conversation, fourth, showing poem and appeal for audience. The theme of has an interesting differences in comparison to the group of best version. When main character awakened, this novel showed the most important message. In the group of best version, he awakened to the cloud that he couldn't distinguish anything. But in this novel, cloud didn't appear, in other words, didn't change the scene. Instead, main character realize himself that he changed from Yang-so-yoo to Seong-jin. It is probable that change of process to conclusion aroused reader and audience's sympathy. To sum up, we could know that this novel kept in mind for play(drama).

Strength and Durability Characteristics of Low-alkali Mortar for Artificial Reefs Produced by 3D Printers (인공어초 3D 프린터 출력을 위한 저알칼리 모르타르의 강도와 내구성능)

  • Lee, Byung-Jae;Kim, Bong-Kyun;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.1
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    • pp.67-72
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    • 2022
  • Concrete prevents corrosion of reinforcing bars due to its strong alkalinity. However, in the sea, strong alkali components with a pH of 12 to 13 are eluted, which adversely affects the ecological environment and growth of marine organisms. In this study, the mechanical properties and durability of the low alkali mortar were evaluated for the development of a low alkali mortar for the 3D printed artificial reefs. As a result of evaluation of strength characteristics, the α-35 mixture, which were produced with fly ash, silica fume and α-hemihydrate gypsum, satisfied the strength requirement 27 MPa in terms of compressive strength. As a result of pH measurement, it was found that mixing with alpha-type hemihydrate gypsum resulted in minimizing pH due to the the formation of calcium sulfate instead of calcium hydroxide production. As a result of the chloride ion penetration resistance test, the α-35 mixture exhibited the best performance, 3844C. As a result of measuring the length change over time, the α-35 mixture showed the shrinkage 33.5% less compared to the Plain mix.

A Study on the Copy of Tripitaka Koreana at Otani University in Kyoto, Japan (일본 오타니대학(大谷大學) 소장 고려대장경 인경본 연구)

  • Jeong, Eunwoo;Shin, Eunjae
    • Korean Journal of Heritage: History & Science
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    • v.52 no.4
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    • pp.38-55
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    • 2019
  • At Otani University in Kyoto, Japan, there is a rubbed copy of Tripitaka Koreana, presumably printed in 1381. According to the postscript of the copy, written by Saek Lee himself, the rubbed copy was made at Haeinsa temple in 1381 and was kept at Sinluksa temple in Yeuju. The copy was delivered as a gift to Japan in 1414 and now is kept at the Library of Otani University. Although an approximate summary of the content of the copy was reported in the early 2000s after a basic survey, details of the copy, including the concrete format and packaging paper, are not known yet. In this paper a detailed survey of the copy is conducted on the 109 pages. The copy is divided into two parts: the wrapping and the inner pages. The wrapping paper is divided into yellow and brown colors depending on the material of the paper. The yellow colorwrapping paper was possibly made in 1381 at the time of the rubbed printing, and the brown wrapping paper was repaired after being moved to Japan. Using funds collected in February 1380, the copy of Gyeong(經), Yul(律), and Ron(論) chapters was printed in April 1381. Binding of the copy was completed in September, and the wrapping paper with the title in gold was made in October 1380. The box for keeping Buddhist scriptures was manufactured in November 1380. The copy was moved to Sinluksa temple in April 1382 and delivered to Japan in 1414. At Otani University, the copy is stored in separate rectangular boxes 32.1×25.3cm in size with a height of 23.6cm. The rectangular plate on the four sides is red in external color but black colorinside. The box for keeping Buddhist scriptures was probably made in 1381, but a partial repair was made later. Because of the difficulty of executing a detailed survey of the box for Buddhist scriptures, it is hard to find out its nation and period of production. We look forward to studying the copy as well as the box for Buddhist scriptures in future.

A Study on the Change of Materials and Fabrication Techniques of Stone Figures in Royal Tombs of the Joseon Period - Focusing on Shindobi, Pyo-Seok, and Sang-Seok - (조선시대 왕릉 석물의 재료와 제작 방법 변화에 관한 연구 - 신도비와 표석, 상석을 중심으로 -)

  • Cha, Moonsung
    • Korean Journal of Heritage: History & Science
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    • v.52 no.4
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    • pp.56-77
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    • 2019
  • Bi-Seok is a treasure trove of funeral rites and an important cultural asset that can shed light on the historical and social history of calligraphy, but research of the topic is still insignificant. In particular, research on the production method of Bi-Seok remains an unproven field. The production of Bi-Seok can be roughly divided into ma-jeong (refining stone), sculpture, and the Buk-chil (process of engraving letters) process. This article reveals some facts: First, performing ma-jeong to the Sang-Seok, Honyu-Seok, Bi-seok, which are known to be God's things. This process is needed because of the change in the perception of the Honyu-Seok due to the settlement and propagation of Confucian ceremonial rituals in the times of hardship in 1592 and 1636. As the crafting process of ma-jeong did not remain concrete, it was only possible to examine the manufacturing process of Bi-Seok through its materials and tools. Second, the rapid proliferation of Oh-Seok and Sa-jeo-chwi-yong (purchase of things made by private citizens) in the Yeongjo era has great importance in social and cultural history. When the Gang-Hwa-Seok of the commodity were exhausted, the Oh-Seok that was used by Sadebu (upper civil class) were used in the tomb of Jangneung, which made Oh-Seok popular among people. In particular, the use of Oh-Seok and the Ma-Jeong process could minimize chemical and physical damage. Third, the writing method of the Bi-seok is Buk-chil. After Buk-Chil of Song Si-Yeol was used on King Hyojong's tomb, the Buk-Chil process ( printing the letters on the back of the stone and rubbing them to make letters) became the most popular method in Korea and among other East Asian countries, and the fact that it was institutionalized to this scale was quite impressive. Buk-Chil became more sophisticated by using red ink rather than black ink due to the black color that results from Oh-Seok. Fourth, the writing method changes in the late Joseon Dynasty. Until the time of Yeongjo's regime, when inscribing, the depth of the angle was based on the thickness of the stroke, thus representing the shade. This technique, of course, did not occur at every Pyo-Seok or Shindobi, but was maintained by outstanding artisans belonging to government agencies. Therefore, in order to manufacture Bi-Seok, Suk-seok, YeonJeong, Ma-jeong, Jeong-Gan, ChodoSeoIp, Jung-Cho, Ip-gak, Gyo-Jeong, and Jang-Hwang, a process was needed to make one final product. Although all of these methods serve the same purpose of paying respects and propagandizing the great work of deceased persons, through this analysis, it was possible to see the whole process of Pyo-Seok based upon the division of techniques and the collaboration of the craftsmen.