• Korean Journal of Metals and Materials
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• v.48 no.6
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• pp.551-556
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• 2010

In this report, we describe mold materials that were used to produce movable metal type by the investment casting method during the Joseon dynasty period in Korea. Samples were obtained from the Wibuinja collection, which is held by the National Museum of Korea. Most of the mold material remnants were found in the depressed areas of the movable type specimens, and we therefore performed non-destructive analyses including XRF, EDS, and XRD. Through these analyses, we were able to identify the mold remnants as hydrocerussite [trilead dihydroxide dicarbonate, $Pb_3(CO_3)_2(OH)_2$] formed in platy hexagonal crystallites. Hydrocerussite was first used to make white pigments and cosmetics in ancient Greece, but this is the first report of hydrocerussite used as mold material applied around a disposable pattern for investment casting. The results of this study will further the understanding of the production process for early movable metal type and ancient casting technologies.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.2
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• pp.57-66
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• 2015

The purpose of this study was to improved the durability of a improved movable weir by replacing the improved movable weir's metal gate with a hybrid steel/glass fiber reinforced polymer composites panel gate. Because the metal gate of a improved movable weir is always in contact with water, its service life is shortened by corrosion. This study made four type of hybrid steel/glass fiber reinforced polymer composites panel gate with different steel gate surface deformation (control, sand blast, scratch and hole), flexural. Fracture properties tests were performed depending on the steel gate surface deformation. According to the test results, the flexural behavior, flexural strength and fracture properties of hybrid steel/glass fiber reinforced polymer composites panel gate was affected by the steel panel gate surface deformation. Also, the sand blast type hybrid steel/glass fiber reinforced polymer composites panel gate shows vastly superior flexural and fracture performance compared to other types.

• Journal of the Korean Society for Library and Information Science
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• v.3
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• pp.47-82
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• 1973

In this study, I have tried to examine the movable type font called 'Chwijinja' (聚珍字) as hitherto and the book printed in Chwijinia for the first time. In order to illustrate the orgin of it more clearly, I introduced Bubyeogru-jungsugi(浮碧樓重修記.) which has been believed the first printed edition of this book and also some other books printed in the same movable type font. By the way, I introduced some views of other bibliographers on Chwijinja. I refuted the views that Chwijinja is metal type and then I substantiated it is wooden type. I also presented three hypotheses on the formation of Chwijinja. I described the reason why we had better change the name of that printing type into 'Bang-Chwijin-pansig Pilseoche Wooden Type'(倣聚珍版式筆書木活字) on the basis of that its name is common noun. I also explained about 'Yeonmu Wooden Type'(燕貿木(唐)字, Wooden Type font imported from China) which is relevant to my description.

• Transactions of Materials Processing
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• v.12 no.8
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• pp.724-729
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• 2003

In order to study the shearing characteristic of anti-vibration sheet metal which is used to reduce vibration noise, a blanking die was manufactured to blank a workpiece. The variables employed in this study were clearance, type of stripper plate, position of the rubber layer and type of the die design. These variables were used to study the effects on burr height, blank diameter and camber height. In the case of burr height from experimental investigation, the push-back die, combined with a movable stripper plate, showed greater burr height. The rubber-top position of a workpiece resulted in better qualities regardless of working variables. In the comparison of diameter measurement, the use of the push-back die with a fixed stripper plate, with a 4.5% clearance, showed better accuracy. For comparing camber height, the push-back die resulted in less cambering than the drop-through die. Also, the larger the clearance, the greater was the camber height. Considering experimental results, the shearing of anti-vibrational sheet metal is best achieved when the rubber layer is laying on the top, blanked with a fixed stripper plate in a push-back die, with a 4.5％ clearance.

• Publications of The Korean Astronomical Society
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• v.33 no.2
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• pp.9-19
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• 2018

We investigate the life of Lee Cheon (1376-1451) who was closely connected with astronomy during the reign of King Sejong of the Joseon dynasty. Lee Cheon is widely regarded as one of the outstanding scientists of King Sejong's period. However, his contributions to the development of the astronomy during the period have not been enlightened. Based on the historical records on the life and achievements of Lee Cheon, mainly referring to the Joseonwangjosillok (Annals of the Joseon Dynasty), we address three important points. First, Lee Cheon was a distinguished administrator who filled various government posts. Second, he was a supervising engineer in public works and metal smelting during his position in military. Third, he was a scientific technician and manufactured precision equipment such as the metal movable type sets. By virtue of these aspects, Lee Cheon was taken into confidence by King Sejong on the Ganui-dae project (i.e., manufacture various astronomical instruments and construct their platform in order to make a calendar suitable for Joseon). During the period of this project, Lee Cheon not only supervised the construction of the Ganui (simplified armillary sphere) and Ganui-dae (platform for astronomical instruments) but also participated in the production of the astronomical instruments such as Gyupyo (Gnomon) and Honcheonui (Armillary Sphere). In conclusion, we regard Lee Cheon as one of the astronomers who led a great advance in astronomy during King Sejong's era.

• Journal of Conservation Science
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• v.37 no.3
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• pp.289-301
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• 2021

When investigating old, printed documents, determining whether a work is printed on a woodblock or using a movable metal type is crucial. It is because the history of printing in Korea and across the world relies on determining the relevant printing invention used and the time of use of the movable metal type. Deciphering details from woodblock and metal prints requires various kinds of information regarding the imprint and the work's printing background, such as information on the characters in the printed document, the outline of the pages, the type of ink used, the production period of the ink, and the production period of the Korean paper. Analyzing such information can generally reveal the production period and the methods used on the old document. However, as such information is not documented systematically, relying on the researcher's judgment based on their experience and perception becomes inevitable. This study conducted an experimental investigation of the printing characteristics of woodblock prints using a replicated woodblock of the Wanpanbon edition of the Shimcheongjeon. Subsequently, the various phenomena and characteristics appearing on the woodblock prints were documented for future reference to determine the printing method of old documents. Finally, woodblock novels without an imprint may be used as a reference to estimate the printing dates by determining the degree of wear on the woodblock.

• Journal of Conservation Science
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• v.33 no.1
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• pp.43-49
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• 2017

The ancient paper document we chose as a case study for our research is "One Hundred Poets of the Tang Dynasty", which is housed in the Ryukoku University Library. The purpose of this research is to introduce a method to analyze the surface roughness and microstructure at a high resolution. In addition, we attempt to quantitatively measure the surface unevenness of the types and curve structure. We used a tridimensional digital microscopy as a non-contact and a non-destructive method to study ancient cultural paper. The information contained in the paper may be lost in the process of applying strong pressure to clean and lining or press. However, this microscopic measurement method can non-destructively analyze a large amount of data in old printed books. Moreover, it enables observing them directly with reflected light. Therefore, this method may be useful for collecting printed information remaining on the surface of the paper.

• Journal of the Korean Home Economics Association
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• v.36 no.6
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• pp.41-56
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• 1998

The Yo-Dae(belt) was made of cloths and leather orginally. Then, it was decorated with metal decoration to become more developed luxury one. The Kwa-Dae of the Three Kingdom period is called as final shape among those ancient mode. Dae-Gu(The origin of belt buckle) was the metallic decoration of the leather belt that the northern nomadic tribe used to wear it. It was considered that the Dae-Gu was more decorated and changed to Kwa-Dae with Yo-Pae. The first stage Dae-Gu didn't have the hook, but a short hook only could move the belt itself was created, and then a movable short hook(China-Jin period Kwa-Dae, etc) to be inside of belt was showed, after that an axis was necessary when it became to long one, It was completed as a belt buckle. The stick shape hook was main stream in China an dthe other northern countries. Meanwhile, Korea has mostly "T" shape hook, and it shows that we developed our own unique style. Classifying the type of the belt plague, there are five types due to the scarved shapes on the Kwa-Dae and the changes. Mainly based on the excavated tomb articles of the three kingdoms and referred to Chinese and Japanese ones. It showed that the belt plague was lightly influenced by the times and area, but was slowly changed and developed to different types through those each ages generally.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.2 no.1
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• pp.102-131
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• 1974

The author's thesis is that the types used for the large-sized characters seen in the two metal type-printed books "Kyosik chubopop karyong"(交食推步法假令) and "Yok-hak kemong yohae"(易學啓蒙要解) both printed in 1458 belong to a new metal font hitherto unnamed. The former book was compiled by Yi Sun-ji(李純之) and Kim Sok-je(金石梯) in January of 1458 in accordance to King Sejo's order. A new font was created to be used for the large-sized characters of the book. Several. months after completion of the compilation, the book was printed with mixed use of the new font and the Kabin-ja(甲寅字) for medium- and small-sized characters. The latter book had been written by King Sejo before his accession to the throne. Ascending the throne the king had his scholar-subjects examine the writing to correct it where necessary. The examination was completed in July of 1458 and printing was immediately done with the two fonts the above-mentioned, new font for the large-sized letters and the Kabin-ja for the medium- and small-sized ones. The books were granted to the scholar-subjects and the students of the Sung Kyun Kwan Academy as a royal gift. The matrix seems to have been modeled after the calligraphy of King Sejo. Because the new font was created to print the large-sized letters of the two books in 1458, it may be proper to name it "Muin-ja" using the "kanji"(干支) of the year. The author is happy to identify and include another font in the list of Korean movable types as a result of the present study.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.10
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• pp.1499-1507
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• 2017

This paper presents an impact-based piezoelectric vibration energy harvester using a freely movable metal sphere and a piezoceramic fiber-based MFC (Macro Fiber Composite) as piezoelectric cantilever. The free motion of the metal sphere, which impacts both ends of the cavity in an aluminum housing, generates power across a cantilever-type MFC beam in response to low frequency vibration such as human-body-induced motion. Impacting force of the spherical proof mass is transformed into the vibration of the piezoelectric cantilever indirectly via the aluminum housing. A proof-of-concept energy harvesting device has been fabricated and tested. Effect of the indirect impact-based system has been tested and compared with the direct impact-based counterpart. Maximum peak-to-peak open circuit voltage of 39.8V and average power of $598.9{\mu}W$ have been obtained at 3g acceleration at 18Hz. Long-term reliability of the fabricated device has been verified by cyclic testing. For the improvement of output performance and reliability, various devices have been tested and compared. Using device fabricated with anodized aluminum housing, maximum peak-to-peak open-circuit voltage of 34.4V and average power of $372.8{\mu}W$ have been obtained at 3g excitation at 20Hz. In terms of reliability, housing with 0.5mm-thick steel plate and anodized aluminum gave improved results with reduced power reduction during initial phase of the cyclic testing.