• Title/Summary/Keyword: site characteristics

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Characteristics of Sr0.92Y0.08Ti1-xVxO3-δ (x = 0.01, 0.04, 0.07, 0.12) Anode for Using H2S Containing Fuel in Solid Oxide Fuel Cells (H2S를 포함하는 연료를 사용하기 위한 고체산화물 연료전지용 Sr0.92Y0.08Ti1-xVxO3-δ 연료극 특성)

  • Jang, Geun Young;Kim, Jun Ho;Mo, Su In;Park, Gwang Seon;Yun, Jeong Woo
    • Korean Chemical Engineering Research
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    • v.59 no.4
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    • pp.557-564
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    • 2021
  • Sr0.92Y0.08Ti1-xVxO3-δ (SYTV) with perovskite structure was investigated as an alternative anode to utilize H2S containing fuels in solid oxide fuel cells. To improve the electrochemical performance of Sr0.92Y0.08TiO3-δ (SYT), vanadium(V) was substituted to titanium(Ti) at the B-site of the SYT perovskites. The SYTV synthesized by the Pechini method was chemically compatible with the YSZ electrolyte without additional by-products formation under the cell fabricating conditions. As increasing V substitution amounts, the oxygen vacancies increased, resulting to increasing ionic conductivity of the anode. The cell performance in pure H2 at 850 ℃ is 19.30 mW/cm2 and 34.87 mW/cm2 for a 1 mol.% and 7 mol.% of V substituted anodes, respectively. The cell performance using H2 fuel containing 1000 ppm of H2S at 850 ℃ was 23.37 mW/cm2 and 73.11 mW/cm2 for a 1 mol.% and 7 mol.% of V substituted anodes, respectively.

A Study on the Usage Behavior of Universities Library Website Before and After COVID-19: Focusing on the Library of C University (COVID-19 전후 대학도서관 홈페이지 이용행태에 관한 연구: C대학교 도서관을 중심으로)

  • Lee, Sun Woo;Chang, Woo Kwon
    • Journal of the Korean Society for information Management
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    • v.38 no.3
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    • pp.141-174
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    • 2021
  • In this study, by examining the actual usage data of the university library website before and after COVID-19 outbreak, the usage behavior of users was analyzed, and the data before and after the virus outbreak was compared, so that university libraries can provide more efficient information services in a pandemic situation. We would like to suggest ways to improve it. In this study, the user traffic made on the website of University C was 'using Google Analytics', from January 2018 to December 2018 before the oneself of the COVID-19 virus and from January 2020 to 2020 after the outbreak of the virus. A comparative analysis was conducted until December. Web traffic variables were analyzed by classifying them into three characteristics: 'User information', 'Path', and 'Site behavior' based on metrics such as session, user, number of pageviews, number of pages per session time, and bounce rate. To summarize the study results, first, when compared with data from January 1 to January 20 before the oneself of COVID-19, users, new visitors, and sessions all increased compared to the previous year, and the number of sessions per user, number of pageviews, and number of pages per session, which showed an upward trend before the virus outbreak in 2020, increased significantly. Second, as social distancing was upgraded to the second stage, there was also a change in the use of university library websites. In 2020 and 2018, when the number os students was the lowest, the number of page views increased by 100,000 more in 2020 compared to 2018, and the number of pages per session also recorded10.46, which was about 2 more pages compared to 2018. The bounce rate also recorded 14.38 in 2018 and 2019, but decreased by 1 percentage point to 13.05 in 2020, which led to more active use of the website at a time when social distancing was raised.

Analysis of Bird Community by Habitat Type in Nak-nam Jeongmaek (낙남정맥의 서식지 유형별 조류 군집 분석)

  • Hwang, Jong-Kyeong;Han, Seung-Woo;Cho, Hae-Jin;Nam, Hyung-Kyu;Yoo, Sung-Yeon;Kwon, In-Ki;Lee, Joon-Woo
    • Korean Journal of Environment and Ecology
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    • v.35 no.2
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    • pp.106-114
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    • 2021
  • This study was conducted to provide basic data for the systematic management and preservation of Nak-nam Jeongmaek. Of the Nak-nam Jeongmaek, six priority research areas, Gilmajae, Mt. Cheonwang, Mt. Yeohang, Mt. Muhak, Mt. Cheonju, Mt. Sineo, with consideration to terrain and environmental characteristics, were selected for this study. Two fixed plots for each bird habitat type were selected for each site and were surveyed from May to October in 2018. The survey conducted in the six priority research areas of Nak-nam Jeongmaek identified 48 species with 1,181 individual birds. The largest number of species and individuals occupying a particular habitat type were found in the developed land with 35 species and 567 individuals. Species diversity was the highest at 2.66 in the forest road. According to the results of nesting guild analysis of Nak-nam Jeongmaek (Pearson Chi-square test, 𝛘2=16.681, p<0.05) by each habitat type, the communities that belong to the canopy nesting guild showed a high frequency in the developed land, the valley, and the forest road. The results of the Pearson Chi-Square test (𝛘2=16.217, p<0.005) showed that the communities that belonged to the bush foraging guild were the most frequent in the developed land, and the communities that belonged to the canopy foraging guild were the most frequent in the valley and the forest road. The results of these studies suggest that the various habitats of the Nak-nam Jeongmaek provide a variety of resources for bird habitats.

A Study on the Complex Color Analysis by Industry for Signboard Improvement Project - Focused on the Jongno-gil, Dongsang-dong, Gimhae-si - (간판개선사업을 위한 업종별 복합 색채 분석 연구 - 김해시 동상동 종로길을 중심으로 -)

  • Park, Han Na;Son, Jeong Eun;Choi, In Kyu;Paik, Jin Kyung
    • Korea Science and Art Forum
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    • v.37 no.4
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    • pp.149-159
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    • 2019
  • This research was started to identify the color status of signboards at the target site and suggest the direction of improvement for the signboard project in Dongsang-dong, Jongno-gil, a central area of the old city center of Gimhae. The area under study forms a depressed street atmosphere with old facilities, and is a typical type of old city center sign that needs to be rebuilt. The purpose of this study is to investigate prior research related to signage and similar signboard improvement cases, and then to identify the current status of colors by sorting out the casting, auxiliary and highlighted colors through the survey of the color of the signboard in the target area, and to propose a desirable direction for the future sign business based on the basis of these findings. This paper divided the target sections by industry and conducted a color analysis of signboards. The results and contents of the research are as follows. First, cast-colored signboards in general businesses showed a variety of primary color distributions with high L* values, on average, with high intensity and high chromaticity. Second, the auxiliary colors were mostly white or black in color-free, making a contrast between the casting colors. Third, the highlight was that a* value showed a high distribution in positive water plus and was mainly distributed in obsolescence, such as red or yellow, and color was used to reflect the characteristics of each store. However, the stores in the entire section lack unity because they were using colors that were higher in color than middle colors, which was causing the street's aesthetic look to be undermined. Based on the results of these studies, it is thought that the future color scheme for Gimhae's signature improvement project will limit the number of colors to a certain extent and give a sense of security and visual comfort to the use of colorlessness and obscurity around the representative colors of Gimhae.

Biodiversity and Characteristic Communities Structure of Freshwater Ecosystems in the Western Area of DMZ, Korea (민통선이북지역(DMZ) 서부평야 일대의 수생태계 생물다양성 및 군집 특성)

  • Jung, Sang-Woo;Kim, Yoon-Ho;Kim, Hyun-Mac;Kim, Su-Hwan
    • Korean Journal of Environment and Ecology
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    • v.32 no.6
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    • pp.603-617
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    • 2018
  • This study surveyed the diversity and community characteristics of benthic macroinvertebrates and freshwater fish, which are the main animal classifications in a hydro ecosystem, from May to September 2017 in the western plains of the Demilitarized Zone (DMZ). The results showed a total of 125 species of benthic macroinvertebrates belonging to 66 families, 19 orders, and four phyla in the streams and wetlands. Among benthic macroinvertebrates, Coleoptera (27 spp.: 21.60%) was the largest group in terms of species richness followed by Odonata (26 spp.: 20.80%), non-Insecta (22 spp.: 17.60%), and Hemiptera (11 spp.: 8.80%) occupying in the lentic area. Of the feeding function groups (FFGs), predators (51 spp.: 56.67%) showed a relatively larger presence, indicating the dominance of hygrophilous invertebrates that usually inhabit the freshwater wetlands or ponds. Of the habitat oriented groups (HOGs), climbers (33 spp.: 24.44%) and burrowers (17 spp.: 12.59%) were the dominant groups. This observation is typical in a slow flowing habitat and can lead to the disturbance of the ecosystem due to cannibalism among predators. Cannibalism can be caused by stress induced by various population and environmental factors. For the ecosystem services benchmark (ESB) value, site 13 appeared to be the highest with 82 marks while other sites showed relatively lower rates and indices (III water quality class with ${\alpha}$-mesosaprobic). The analysis result of stability factors showed that almost all sites were evaluated to be the I characteristic group with high resilience and resistance or the III characteristic group that was sensitive to environmental disturbance and formed uneven and unstable communities. Of the freshwater fishes, 46 species (3,405 individuals) belonging to 39 families and 18 orders were identified in all the investigated sites. Among them, Cyprinidae (30 spp.: 65.2%) was the largest group, and Zacco koreanus was identified as the dominant species (728 individuals, 21.4%). The survey of freshwater fish communities found both stable communities (sites 7 and 13) with low dominant index (0.39) and high diversity index (2.29) and unstable communities (sites 2, 3, 8, and 10) in opposite tendency. This survey found five Korean endemic species, 17 species belonging to the export controlled species, two endangered species level II (Lethocerus deyrollei and Cybister chinensis), and rare species (Dytiscus marginalis czerskii) among benthic macroinvertebrates. The survey also found an invasive species, Ampullarius insularus, which was distributed throughout the whole area and thus can continuously disturb the ecosystem in the western plain area in the DMZ. Of freshwater fish, one natural monument (Hemibarbus mylodon) and three endangered species level II (Acheilognathus signifer, Gobiobotia macrocephalus, and G. brevibarba) were observed. The survey also found four introduced species (Pomacea canaliculate, Carassius cuvieri, Lepomis macrochirus, Micropterus salmoides) in the western DMZ area, indicating the need for the protection and conservation measures.

The Development and Originality of Wind Chimes of the Goryeo Dynasty (고려시대 풍탁(風鐸)의 전개와 독창성)

  • Lee, Young-sun
    • Korean Journal of Heritage: History & Science
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    • v.52 no.2
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    • pp.292-307
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    • 2019
  • Buddhists have always tended to adorn and embellish Buddhist statues and their surrounding spaces in order to exhibit the grandeur and sublime nature of the Buddha. The various kinds of splendid instruments and implements used in such ornamentation are collectively called jangeomgu in Korean. Thus, the term jangeomgu encompasses articles used to decorate Buddhist statues, halos, and baldachin, as well as Buddhist banners and wind chimes, which are generally hung outside a building. Wind chimes are still widely used at Buddhist temples. In China, judging from various structures such as the Wooden Stupa of Yongningsi in Luoyang and the Dunhuang Caves, wind chimes began to be used around the sixth century. As for Korea, Buddhism was first introduced from China during the Three Kingdoms Period, and Koreans accordingly began to build Buddhist temples and buildings. It would appear that wind chimes came to be used around the time that the first temples were built. The oldest extant wind chime in Korea is the gilt-bronze wind chime of Baekje, discovered at the Mireuksa Temple Site in Iksan. In general, Korean wind chimes dating from the Three Kingdoms Period are classified into two general types according to their shape and elevation, i.e., those shaped like a Buddhist bell and those shaped like a trapezoid. As these two forms of wind chimes have influenced each other over time, those made during the Goryeo dynasty, having inherited the style, structure, and design of the preceding period, display such features. At the same time, the artisans who produced wind chimes pursued technical development and adopted free, yet not extravagant, designs. In particular, Goryeo wind chimes are characterized by original designs created through exchanges with other Buddhist art forms of the same period, such as the embossed lotus design band of Goryeo bells; the bullmun design, which served to display the grandeur of the royal family; the samhwanmun design, which consisted of decorating the interior of a Goryeo incense burner with three holes; Sanskrit designs; and designs inspired by the windows and doors of stone pagodas. In this way, the production of Goryeo wind chimes developed with a focus on purpose while being free of formal constraints. This study started out from the fact that the largest number of Korean wind chimes were produced during the Goryeo dynasty. Therefore, research on wind chimes should be based on those of the Goryeo dynasty, especially since fewer relevant studies have been conducted compared to studies on other forms of Buddhist art. For the purposes of this study, the reasons for the production of wind chimes will be examined first, followed by an examination of the various styles of Korean wind chimes. Then, based on the findings of this investigation, the development and characteristics of the wind chimes produced during the Goryeo dynasty will be explored for each period.

Garden Construction and Landscape Characteristics of the Seochulji Pond Area in Gyeongju during the Middle of the Joseon Dynasty (조선 중기 경주 서출지(書出池) 일원의 정원 조영과 경관 특성)

  • Kim, Hyung-suk;Sim, Woo-kyung
    • Korean Journal of Heritage: History & Science
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    • v.52 no.2
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    • pp.62-79
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    • 2019
  • This study examined the background of Gyeongju Seochulji Pond (world heritage, historic site No. 138), a historic pond in Sam-guk-yu-sa (三國遺事), and its landscaping period when it served as the garden of the Pungcheon Lim clan (豊川 任氏) in the middle of the Joseon dynasty. For this study, a literature review of poetry, prose, and a personal anthology, and a field survey were conducted. Changes in the landscape were analyzed by comparing the landscape appearing in the literature of the Joseon period with past photographs. The results were as follows: First, even though the function and landscape at that time cannot be guessed as the objective ground from Silla to the early part of the Joseon dynasty is insufficient, it has been managed as a Byeolseo (別墅) garden as Pungcheon Lim's family resided in the area of Eastern-Namsan Mountain during the Joseon dynasty. At that time, Seochulji Pond was recognized as a historic place. It functioned as the garden of Pungcheon Lim's family as Lim Jeok (任勣, 1612~1672) built the Yiyodang pavilion (二樂堂). Second, in the literature, the Yiyodang pavilion has been called Gaekdang (客堂), Jeongsa (精舍), Byeolgak (別閣) and Byeolseo, etc. It can be seen as Nu and Jeong (樓亭), utilized for various uses. Because of this, the name Bingheoru Pavilion (憑虛樓) has mostly been in common use. Third, Seochulji Pond was positioned where the scenery is beautiful, with Gyeongju Mt. Namsan (Mt. Geumo) in the background and with a wide field and the Namcheon River flowing in the front. This was typical of Byeolseo gardens of the Joseon dynasty, combining human environments with natural environments. Fourth, the relationship with the Byeolseo garden disappeared as the head of Pungcheon Lim's family added a temple, lotus flowers, pine trees, and a bamboo forest as described in the old poetry and prose. Currently, the landscape does not appear to be significantly different from that as development has not occurred in the area of Seochulji Pond. Also, crape myrtle (Lagerstroemia indica), which now symbolizes the Seochulji Pond, was not identified in the old poetry or past photographs and is not old enough to confirm whether it was prominent at the time. Through this study, it is necessary to reconsider the spatial meanings of the gardens of the Joseon dynasty period and not to highlight the area of Seochulji Pond as a place in the legend. This is a cultural asset in the area of Eastern-Namsan Mountain and has an important meaning in terms of garden history.

A Study of the Construction and Change of Chugyeongwon in Donggweol (동궐(東闕) 추경원(秋景苑)의 조영과 변천에 관한 고찰)

  • Oh, Jun-young
    • Korean Journal of Heritage: History & Science
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    • v.52 no.1
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    • pp.44-63
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    • 2019
  • This study empirically investigated the construction and aspects of change in Chugyeongwon, which is located in Donggweol (東闕). In detail, this study investigated the location of the construction and range of Chugyeongwon, the background and intention of the construction, and the affiliated system and aspects of spatial changes of it. The research results can be summarized as follows: First, Chugyeongwon has been assumed to be the space near Haminjeong (涵仁亭) or between Simindang (時敏堂) and Jinsudang (進修堂) in Changgyeonggung Palace. However, according to related historical materials, it is said that Chugyeongwon was located west of Dochongbu (都摠府) in Hyeopsangmun (協祥門) and near Sungmundang (崇文堂). Through Donggweoldohyeong (東闕圖形), evidence of the construction of Chugyeongwon can be found, which verifies such claims. According to The Plan of Changgyeonggung Palace (昌慶宮配置圖), in the form of modern measured drawing, Chugyeongwon today is the green space created in the south of Munjeongjeon (文政殿) and Sungmundang in Changgyeonggung Palace. Second, According to Donggweoldo (東闕圖), Chugyeongwon was a green space where trees grew on the ground within the walls. No artificial facilities were constructed inside. In addition, Chugyeongwon was located at a site with an altitude higher than the surroundings. Especially, the composition forms and location characteristics of Chugyeongwon are similar to those of the Palace Outer Garden located in Hanyang. Thus, based on this evidence about the form and other aspects of the operation of the Palace Outer Garden, it can be inferred that Chugyeongwon was constructed for the preservation and cultivation of the geographical features inside Donggweol. Third, in the late Joseon period, Chugyeongwon was assigned to Changdeokgung Palace or Changgyeonggung Palace in the same manner as was Donggung (東宮). Thus, it is very likely that Chugyeongwon served as a garden for the Royal Family in the Donggung area. The west boundary of Chugyeongwon, which originally consisted of walls and a side gate, was changed into the form in which the walls and colonnades were combined. Chugyeongwon has been modified due to various acts of development since the Japanese colonial era, and in the end, it has disappeared so that no trace can be found.

A Study on the Characteristics of Historical Landscape Management Plans for Zhoucun Ancient Mall in Zibo City, Shandong Province, China (중국 산동성 쯔보시 주촌고상성 역사경관관리계획의 특성)

  • Sun, Shu-Zi;Yang, Geon-Seok
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.37 no.2
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    • pp.54-65
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    • 2019
  • China government recently tries to preserve not only the famous national historic-culture cities, but also the small and medium-sized cities due to the damages and destruction of the cities by the rapid economic development, urban expansion and the development of tourism industry. Hence, this study chose 'Zhoucun ancient mall' which is one of the hotness of cultural heritage located in a mid-sized city named 'Zhoucun district Zibo city Shandong province' that has continuously cared historical landscapes by the protective policy regarding the city as a historic-culture resource from '80s, and considered the character of the city's development process on how the historical landscapes were well protected. In fact, the protection policy in Zhoucun ancient mall had been started in early '80s, however, the viable plan was established in 2001 entitled 'Historical block protection planning of Zhoucun Da street'. And then, 'Regulatory plan for the ancient mall site of Zhoucun Da street' established in 2008 has expanded the area of the blocks for protection. However, this plan organized area only block-by-block so that the small blocks couldn't have the unity when expanded. Later in 2015, 'Regulation Organization Plan' hastried to expanded the protect-area to solve the unity problem. As a result of the study, the historical landscape management plan of Zhoucun in Zibo city has been systematically changed in 2001 after. In other words, this 2001's plans established buffer zones for the maintenance of protected areas and the surrounding environment. And then the detailed regulatory plan for 2008 led to a concrete urban management plan. After that, in 2015, it was found that the expansion plan to protect and manage the whole area of Zhoucun disrict is to manage the landscape of the surrounding area including the historical landscape of 'Zhoucun ancient mall'.

The Sillok as National Supreme Archives : An archival interpretation (실록(實錄) : 등록(謄錄)의 위계(位階))

  • O, Hang-Nyeong
    • The Korean Journal of Archival Studies
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    • no.3
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    • pp.91-113
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    • 2001
  • History always be re-interpreted as the time flows. 'The Sillok', Which was registered in Memory of World of UNESCO in 1997, is comprehensive documents of the Chosun Dynasty, which had been compiled after kings' death, The Sillok encompasses 473 years of the reign in their 848 volumes(1,893 chapters). It was a history itself and has been main source in studying Korean history. Due to the rise of studies on the Sillok, time has come to explore the nature of the Sillok and to criticize the text, which would be called 'The Sillok-Study'. In this context, this paper examined three concepts that categorize the nature of the Sillok as historical materials ;Is it book or record?; The Sillok in register system in pre-modern society; And the Sillok as the National Archives. Korean historians, including myself, haven't yet examined the question whether the Sillok is the Book or Record in terms of archival science. At first, I regarded it as history book, and with this presupposition, wrote several papers on the characteristics of the Sillok. However, I recognized that the Sillok are close to record rather that history book as I examined the definition of glossary of librarian study, OED (Oxford English Dictionary) and Encyclopedia of Britannica, etc. Definitely, the Sillok was neither compiled and published to be read and sold publicly, nor meant to the works of literature or scholarship. one may say that the court-historians wrote comments on the facts and therefore it was just scholarly work. However, because the court-historians produced their comments on their own businesses, the outcome of 'their scholarly works' were also records conceptually, as were daily court-journalists in Rome. Its publication also had a absolutely different meaning from that of modern society. It was a method to preserve the important national records and distributed each edition of them to plural repositories for its safety and security. How can we explain its book-like shape and the procedure of compilation after a kings' death. The answer is as follows ; In pre-modern society, it was a common record-keeping system in the world to register records materials in order to arrange the materials of different sizes and to store them conveniently. And the lack of scientific preservation or conservation skill also encouraged them to register original records. Actually, the court-historians who participated in the compiling process called themselves "registering officers". On the other hand, similar to social hierarchy, there was a hierarchical system of records, and the Sillok was placed at the top of this hierarchy. In conclusion, the Sillok was a kind of registered records in the middle ages and the supreme records in the records-world. In addition to this we can also conceptualize the Sillok as archives. Through the compiling process, the most important and valuable records were selected to be the parts of Sillok. This process corresponds to the modem records appraisal. In the next step, it was preserved in the Four Archives(史庫) which located at remote site as archives and only accessible by the descendents in the future, who might be the people of the next dynasty. And nobody could access or read the documents at that time except the authorized court-historians who were archivists of the Chosun Dynasty. From this perspective, I conclude that Sillok was the supreme confidential archives in the register system. I work for the Government Archives as a historian and archivist. Whenever I entered the exhibition hall of the Government Archives and Records Service(GARS) and saw the replica of the Archives of Taebeak Mountain built during Chosun period, I always asked to myself a question whether the Sillok can be a symbol of the archival tradition of Korea and the GARS. Now, I can say, 'Yes!' definitely.