• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.25-30
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• 2023

As 3D printing technology is used in the medical field, interest in metal materials is increasing. The Department of Radiation Oncology uses a shielding block to shield the patient's normal tissue from unnecessary exposure during electron beam therapy. However, problems such as handling of heavy metal materials such as lead and cadmium, reproducibility according to skill level and uncertainty of arrangement have been reported. In this study, candidate materials that can be used for metal 3D printing are selected, and the physical properties and radiation dose of each material are analyzed to develop a customized shielding block that can be used in electron beam therapy. As candidate materials, aluminum alloy (d = 2.68 g/cm³), titanium alloy (d = 4.42 g/cm³), and cobalt chromium alloy (d = 8.3 g/cm³) were selected. The thickness of the 95% shielding rate point was derived using the Monte Carlo Simulation with the irradiation surface and 6, 9, 12, and 16 energies. As a result of the simulation, among the metal 3D printing materials, cobalt chromium alloy (d = 8.3 g/cm³) was similar to the existing shielding block (d = 9.4 g/cm³) in shielding thickness for each energy. In a follow-on study, it is necessary to evaluate the usefulness in clinical practice using customized shielding blocks made by metal 3D printing and to verify experiments through various radiation treatment plan conditions.

• The Journal of Advanced Prosthodontics
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• v.11 no.2
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• pp.95-104
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• 2019

PURPOSE. To evaluate the effect of surface treatments and repair materials on the shear bond strength and to measure the fracture toughness of CAD/CAM provisional restoration materials. MATERIALS AND METHODS. Four CAD/CAM (3D printing: Nextdent C&B and ZMD-1000B Temporary, CAD/CAM resin block: Yamahachi PMMA disk and Huge PMMA block) and four conventional (monometacrylate: Jet and Alike, dimetacrylate: Luxatemp and Protemp 4) materials were selected to fabricate disk-shaped specimens and divided into six groups according to surface treatment (n=10). CAD/CAM materials were repaired with Jet or Luxatemp, while conventional materials were repaired with their own materials. The shear bond strength was measured by using universal testing machine. Ten rectangular column-shaped specimens for each material were fabricated to measure the fracture toughness by single edge v notched beam technique. Statistical analysis was performed by one-way ANOVA. RESULTS. The highest shear bond strength of CAD/CAM materials was achieved by SiC paper + sandblasting. It was also accomplished when repairing 3D printing materials with Luxatemp, and repairing CAD/CAM resin blocks with Jet. Yamahachi PMMA disk showed the highest fracture toughness. Nextdent C&B showed the lowest fracture toughness value but no statistically significant difference from Alike and Luxatemp (P>.05). CONCLUSION. In order to successfully repair the CAD/CAM provisional restoration, mechanical surface treatment and appropriate repair material according to the CAD/CAM material type should be selected. The CAD/CAM provisional materials have proper mechanical properties for clinical use as compared to conventional materials.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.115-122
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• 2009

In shipbuilding process, automated marking systems are used to print steel part information on the steel plate. Especially, an automated marking system with a moving ink-head prints characters on each block, which divide the steel plate into a fixed size. Therefore it is necessary to split characters, because some characters can be extended into several blocks. Particularly the algorithm, which splits characters, must guarantee its printing quality in any direction since characters can be printed by any angle.

• Journal of the Korean Society for Library and Information Science
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• v.28
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• pp.71-81
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• 1995

There are no exact copies or carvings of India's original Buddhist Scripts published in Korea that had been flowed into Japan except those of WanSanJungUiMongSanPuPo(환산정의몽산법어). YaWoonJaKyung (야운자경). KyeChoShimHakInMoon(계초심학인문) PalSimSooHangChang(발심수행장) and MongsanWhaSangPupoRackLock published by a mid-Chosun Dynasty Buddhist monk, YaWoon TaesunSa. Others are the translations by Chinese people. All printings were of woodblock except ChonjimyungYangsoo- RhockChapMoon(천지명양수육잡문) of Inkyng wood printing type. This shows perhaps that the Buddhists were so devout that they spared no effort in their prayers to head for the Paradise. Even the woodblock carver himself took his hard work for granted in his belief and engraved the blocks with all his heart taking his work as God-given task. Or. perhaps they to use wood-block printing as the demand for the Scripts soared. By the way. as the Koryo Dynasty took Buddhism as the state religion, it was natural that the Buddhist Scripts were published at TaeJangToKam (the publishing office) and were much encouraged. It is noteworthy. however, that not a few Buddhist Scripts had been published during the Chosun Dynasty despite its crack-down on Buddhism as the Confucianism was declared as the state principle. The Scripts were even published by such temples as MoonJooSa(문수사), MyoHeeAm(묘희암). SsangbongSa(쌍봉사). PyoHoonSa(표훈사), YooJupSa(유점사), YongJangSa(용장사). and AnShimSa(안심사). The fact that the Scripts were even published by KanKyungToKam(간경부감) leads us to reconsider the traditional way of thinking of the Chosun Dynasty as anti-Buddhist or flunkeyist. The historical fact that a record number of Buddhist publications had been transmitted to Japan - is it accidental? - This issue could well be another subject matter for further research. However, it should be noted that very few of above­mentioned Buddhist Scripts are found in present-day Korea.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.22 no.1
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• pp.27-46
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• 2011

The present paper is focused on Korea's inscribed heritages, digitization of the Tripitaka Koreana & miscellaneous buddhist scriptures, and public uses of the digital properties in order to describe the Digitization & Popularization of Printing Woodblocks of the Tripitaka Koreana and Miscellaneous Buddhist Scriptures, Memory of the World. The Goryeo Daejanggyeong or the Tripitaka Koreana and miscellaneous Buddhist sculptures refer to printing woodblocks of the Tripitaka(National Treasure No.32), and repositories (National Treasure No.52) where the woodblocks are stored. The woodblocks numbers 1,514 types/81,350 blocks/162,700 pages. Haein temple has worked the digital Tripitaka project 2009-2010 and The project for 2010 will focus on DB correction and modification, improvement of homepage that was made in 2009. For this, the focus was especially put on investigating current status and development plans of the digital Tripitaka project. In popularization of the digital Tripitaka, this study examined the Korea's utilization policy and current situation of knowledge resources about culture, successful cases of digital Tripitaka projects, and popularization strategies. This research can contribute to digitization of other cultural heritages and related researches in the future.

• Journal of KIISE
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• v.41 no.9
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• pp.728-743
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• 2014

Finger printing and sequence alignment are well-known approaches for document similarity comparison. A fingerprinting method is simple and fast, but it can not find particular similar regions. A string alignment method is used for identifying regions of similarity by arranging the sequences of a string. It has an advantage of finding particular similar regions, but it also has a disadvantage of taking more computing time. The Multi-Level Alignment (MLA) is a new method designed for taking the advantages of both methods. The MLA divides input documents into uniform length blocks, and then extracts fingerprints from each block and calculates similarity of block pairs by comparing the fingerprints. A similarity table is created in this process. Finally, sequence alignment is used for specifying longest similar regions in the similarity table. The MLA allows users to change block's size to control proportion of the fingerprint algorithm and the sequence alignment. As a document is divided into several blocks, similar regions are also fragmented into two or more blocks. To solve this fragmentation problem, we proposed a united block method. Experimentally, we show that computing document's similarity with the united block is more accurate than the original MLA method, with minor time loss.

• MISULJARYO - National Museum of Korea Art Journal
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• v.98
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• pp.104-129
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• 2020

Designated as a national treasure of Korea and inscribed on the UNESCO World Heritage List, the Tripitaka Koreana at Haeinsa Temple is the world's oldest and most comprehensive extant version of the Tripitaka in Hanja script (i.e., Chinese characters). The set consists of 81,352 carved woodblocks, some of which have two or more copies, which are known as "duplicate woodblocks." These duplicates are supplementary woodblocks (bogakpan) that were carved some time after the original production, likely to replace blocks that had been eroded or damaged by repeated printings. According to the most recent survey, the number of supplementary woodblocks is 118, or approximately 0.14% of the total set, which attests to the outstanding preservation of the original woodblocks. Research on the supplementary woodblocks can reveal important details about the preservation and management of the Tripitaka Koreana woodblocks. Most of the supplementary woodblocks were carved during the Joseon period (1392-1910) or Japanese colonial period (1910-1945). Although the details of the woodblocks from the Japanese colonial period have been recorded and organized to a certain extent, no such efforts have been made with regards to the woodblocks from the Joseon period. This paper analyzes the characteristics and production date of the supplementary woodblocks of the Tripitaka Koreana. The sutra with the most supplementary woodblocks is the Maha Prajnaparamita Sutra (Perfection of Transcendental Wisdom), often known as the Heart Sutra. In fact, 76 of the total 118 supplementary woodblocks (64.4%) are for this sutra. Hence, analyses of printed versions of the Maha Prajnaparamita Sutra should illuminate trends in the carving of supplementary woodblocks for the Tripitaka Koreana, including the representative characteristics of different periods. According to analysis of the 76 supplementary woodblocks of the Maha Prajnaparamita Sutra, 23 were carved during the Japanese colonial period: 12 in 1915 and 11 in 1937. The remaining 53 were carved during the Joseon period at three separate times. First, 14 of the woodblocks bear the inscription "carved in the mujin year by Haeji" ("戊辰年更刻海志"). Here, the "mujin year" is estimated to correspond to 1448, or the thirtieth year of the reign of King Sejong. On many of these 14 woodblocks, the name of the person who did the carving is engraved outside the border. One of these names is Seonggyeong, an artisan who is known to have been active in 1446, thus supporting the conclusion that the mujin year corresponds to 1448. The vertical length of these woodblocks (inside the border) is 21 cm, which is about 1 cm shorter than the original woodblocks. Some of these blocks were carved in the Zhao Mengfu script. Distinguishing features include the appearance of faint lines on some plates, and the rough finish of the bottoms. The second group of supplementary woodblocks was carved shortly after 1865, when the monks Namho Yeonggi and Haemyeong Jangung had two copies of the Tripitaka Koreana printed. At the time, some of the pages could not be printed because the original woodblocks were damaged. This is confirmed by the missing pages of the extant copy that is now preserved at Woljeongsa Temple. As a result, the supplementary woodblocks are estimated to have been produced immediately after the printing. Evidently, however, not all of the damaged woodblocks could be replaced at this time, as only six woodblocks (comprising eight pages) were carved. On the 1865 woodblocks, lines can be seen between the columns, no red paint was applied, and the prayers of patrons were also carved into the plates. The third carving of supplementary woodblocks occurred just before 1899, when the imperial court of the Korean Empire sponsored a new printing of the Tripitaka Koreana. Government officials who were dispatched to supervise the printing likely inspected the existing blocks and ordered supplementary woodblocks to be carved to replace those that were damaged. A total of 33 supplementary woodblocks (comprising 56 pages) were carved at this time, accounting for the largest number of supplementary woodblocks for the Maha Prajnaparamita Sutra. On the 1899 supplementary woodblocks, red paint was applied to each plate and one line was left blank at both ends.

• Journal of Korean Society of Archives and Records Management
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• v.5 no.2
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• pp.27-48
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• 2005

This study investigates the current preservation and management of four records and documentary heritage in Korea that is in the UNESCO's Memory of the World Register. The study analyzes their problems and corresponding solutions in digitizing those world records heritages. This study also reviews additional four documentary books in Korea that are in the wish list to add to UNESCO's Memory of the World Register. This study is organized as the following: Chapter 2 examines the value and meanings of world records and documentary heritage in Korea. The registry requirements and procedures of UNESCO's Memory of the World Register are examined. The currently registered records of Korea include Hunmin-Chongum, the Annals of the Choson Dynasty, the Diaries of the Royal Secretariat (Seungjeongwon Ilgi), and Buljo- Jikji-Simche-Yojeol (vol. II). These records heritage's worth and significance are carefully analyzed. For example, Hunmin-Chongum("訓民正音") is consisted of unique and systematic letters. Letters were delicately explained with examples in its original manual at the time of letter's creation, which is an unparalleled case in the world documentary history. The Annals of the Choson Dynasty("朝鮮王朝實錄") are the most comprehensive historic documents that contain the longest period of time in history. Their truthfulness and reliability in describing history give credits to the annals. The Royal Secretariat Diary (called Seungjeongwon-Ilgi("承政院日記")) is the most voluminous primary resources in history, superior to the Annals of Choson Dynasty and Twenty Five Histories in China. Jikji("直指") is the oldest existing book published by movable metal print sets in the world. It evidences the beginning of metal printing in the world printing history and is worthy of being as world heritage. The review of the four registered records confirms that they are valuable world documentary heritage that transfers culture of mankind to next generations and should be preserved carefully and safely without deterioration or loss. Chapter 3 investigates the current status of preservation and management of three repositories that store the four registered records in Korea. The repositories include Kyujanggak Archives in Seoul National University, Pusan Records and Information Center of National Records and Archives Service, and Gansong Art Museum. The quality of their preservation and management are excellent in all of three institutions by the following aspects: 1) detailed security measures are close to perfection 2) archiving practices are very careful by using a special stack room in steady temperature and humidity and depositing it in stack or archival box made of paulownia tree and 3) fire prevention, lighting, and fumigation are thoroughly prepared. Chapter 4 summarizes the status quo of digitization projects of records heritage in Korea. The most important issue related to digitization and database construction on Korean records heritage is likely to set up the standardization of digitization processes and facilities. It is urgently necessary to develop comprehensive standard systems for digitization. Two institutions are closely interested in these tasks: 1) the National Records and Archives Service experienced in developing government records management systems; and 2) the Cultural Heritage Administration interested in digitization of Korean old documents. In collaboration of these two institutions, a new standard system will be designed for digitizing records heritage on Korean Studies. Chapter 5 deals with additional Korean records heritage in the wish list for UNESCO's Memory of the World Register, including: 1) Wooden Printing Blocks(經板) of Koryo-Taejangkyong(高麗大藏經) in Haein Temple(海印寺); 2) Dongui-Bogam("東醫寶鑑") 3) Samguk-Yusa("三國遺事") and 4) Mugujeonggwangdaedaranigyeong. Their world value and importance are examined as followings. Wooden Printing Blocks of Koryo-Taejangkyong in Haein Temple is the worldly oldest wooden printing block of cannon of Buddhism that still exist and was created over 750 years ago. It needs a special conservation treatment to disinfect germs residing in surface and inside of wooden plates. Otherwise, it may be damaged seriously. For its effective conservation and preservation, we hope that UNESCO and Government will schedule special care and budget and join the list of Memory of the Word Register. Dongui-Bogam is the most comprehensive and well-written medical book in the Korean history, summarizing all medical books in Korea and China from the Ancient Times through the early 17th century and concentrating on Korean herb medicine and prescriptions. It is proved as the best clinical guidebook in the 17th century for doctors and practitioners to easily use. The book was also published in China and Japan in the 18th century and greatly influenced the development of practical clinic and medical research in Asia at that time. This is why Dongui Bogam is in the wish list to register to the Memory of the World. Samguk-Yusa is evaluated as one of the most comprehensive history books and treasure sources in Korea, which illustrates foundations of Korean people and covers histories and cultures of ancient Korean peninsula and nearby countries. The book contains the oldest fixed form verse, called Hyang-Ka(鄕歌), and became the origin of Korean literature. In particular, the section of Gi-ee(紀異篇) describes the historical processes of dynasty transition from the first dynasty Gochosun(古朝鮮) to Goguryeo(高句麗) and illustrates the identity of Korean people from its historical origin. This book is worthy of adding to the Memory of the World Register. Mugujeonggwangdaedaranigyeong is the oldest book printed by wooden type plates, and it is estimated to print in between 706 and 751. It contains several reasons and evidence to be worthy of adding to the list of the Memory of the World. It is the greatest documentary heritage that represents the first wooden printing book that still exists in the world as well as illustrates the history of wooden printing in Korea.

• Journal of the Korean Society for Library and Information Science
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• v.28
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• pp.301-390
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• 1995

In this paper, I intended to study the policy executed by the king Sungjong(성종), the ruler of the early Chosun(조선) Dynasty, for the purpose of the training for the literary scholars under the diplomatic necessity and from his own interest in literature, and the compilation and the publication of anthologies of the famous civil officials in those days under the influence of this policy. The overall findings of the study can be summarized as follows : 1. Sungjong was comparable with the Sejong(세종) in his studiousness and especially, he was very interested in literature. He composed verses personally, showed them to his civil officials and demanded their poems in response to his own ones. Futhermore, he executed steadily the institutions of Eung-je(응제), Kaw-si(과식) and Weol-kwa(월과) that demanded creative writings from his civil officials. The purpose of these institutions which was propelled by the king Sungjong was the training for the literary scholars under the diplomatic necessity. 2. Chosun Dynasty exchanged envoys with Myeong(명) Dynasty during the time of the king Sungjong as many as 100 times. The training for the excellent literary scholars was nationally urgent problem because the competent literary scholars were needed whenever Myeong Dynasty dispatched the envoys to Chosun Dynasty. Eung-je, Kwa-si and Weol-kwa were executed from practical demand and 1 - 3 persons at the minimum, 60 - 70 persons at the maximum took part in this institution at a time. This means that 60 - 70 literary works were produced at a time. Therefore, the steady execution of Eung-je, Kwa-si and Weol-kwa inevitably resulted in mass production of literary works. 3. The king Sungjong instructed his civil officials to compile the anthologies of the then representative civil officials as a means to encourage literary compositions, read it himself and took actions to publish them at the expense of government. There were six anthologies compiled and published under this policy of the king Sungjong, Kang Heui­maeng's Sasukjejib(강희맹, 사숙제집), Shin Suk-ju's Bohanjaejib(신숙단, 보한제집), Kim Su-on's Shikujib (김수온, 식우집), Choe Hang's Taeheojeongjib(최항, 태허정집), Seo Keo-jeong's Sagajib (서거정, 사가집), Lee Seok-hyeong's Jeoheonjib(이석형, 저헌집). Yu Ho-in's Noekyejib(유호인, 뇌계집+CZ48), Lee Seung-so's Samtanjib(이승소, 삼탄집), Kim Jong-jik's Jeompiljaejib(김종직, 점필제집) of three were examined by the king Sungjong, but published later because of the death of the king. 4. jeompiljaejib was compiled by order of the king Sungjong and passed Eulram (을람 : king reads an anthology personally) which contained Joeuijemoon(조의제문) that criticized the king Sejo(세조) who had usurped a throne. The recording of Joeuijemoon became an issue in process of Muosahwa(무오사화), and it was ordered that the printing blocks should be broken and the published books should be collected and be burnt up. These procedures destroyed the social atmosphere that people considered it an honor writing literary compositions, compiling and publishing anthologies thanks to the steady efforts of the king Sungjong. 5. It had an important effect on the compilation and the publication of anthologies after that, breaking the printing blocks, collecting and burning up the pulished books of Jeompiljaejib because of recording of Joeuijemoon. Namely, it got universalized to delete compositions that can cause problems in the future as well as the parts related to political issue, from the objects of recording. Such tendency became one of the important principles of the anthological compilation after that.

• The Journal of Advanced Prosthodontics
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• v.14 no.6
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• pp.360-368
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• 2022

PURPOSE. This study assessed the physical and mechanical properties of interim crown materials fabricated using various digital techniques after accelerated aging. MATERIALS AND METHODS. Three groups of interim dental restorative materials (N = 20) were tested. The first group (CO) was fabricated using a conventional manual method. The second group (ML) was prepared from prefabricated resin blocks for the milling method and cut into specimen sizes using a cutting disc. The third group (3D) was additively manufactured using a digital light-processing (DLP) 3D printer. Aging acceleration treatments using toothbrushing and thermocycling simulators were applied to half of the specimens corresponding to three years of usage in the oral environment (N = 10). Surface roughness (Ra), Vickers microhardness, 3-point bending, sorption, and solubility tests were performed. A 2-way analysis of variance (ANOVA) and Fisher's multiple comparison test were used to compare the results among the groups. RESULTS. The mean surface roughness (Ra) of the resin after accelerated aging was significantly higher in the CO and ML groups than that before aging, but not in the 3D group. All groups showed reduced hardness after accelerated aging. The flexural strength values were highest in the 3D group, followed by the ML and CO groups after accelerated aging. Accelerated aging significantly reduced water sorption in the ML group. CONCLUSION. According to the tested material and 3D printer type, both 3D-printed and milled interim restoration resins showed higher flexural strength and modulus, and lower surface roughness than those prepared by the conventional method after accelerated aging.