• Journal of the Korea Concrete Institute
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• v.18 no.6 s.96
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• pp.811-817
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• 2006

The primary purpose of this study is to estimate the guaranteed strength and construction quality of the combined high flowing concrete which is used in the slurry wall of underground LNG storage tank. The required compressive strength of this type of concrete become generally known as a non economical value because it is applied the high addition factor for variation coefficients and low reduction factor under water concrete. Therefore, after estimation of the construction quality and guaranteed strength in actual site work, this study is to propose a suitable equation to calculate the required compressive strength in order to improve its difference. Application results in actual site work are shown as followings. The optimum nix design proportion is selected that has water-cement ratio 51%, sand-aggregate ratio 48.8%, and replacement ratio 42.6% of lime stone powder by cement weight. Test results of slump flow as construction quality give average 616~634mm. 500mm flowing time and air content are satisfied with specifications in the rage of 6.3 seconds and 4.0% respectively. Results of strength test by standard curing mold show that average compressive strength is 49.9MPa, standard deviation and variation coefficients are low as 1.66MPa and 3.36%. Also test results by cored cylinder show that average compressive strength is 66.4MPa, standard deviation and variation coefficients are low as 3.64MPa and 5.48%. The guaranteed strength ratio between standard curing mold and cored cylinder show 1.23 and 1.32 in the flanks. It is shown that applied addition factor for variation coefficients and reduction factor under water concrete to calculate the required compressive strength is proved very conservative. Therefore, based on these results, it is proposed new equation having variation coefficients 7%, addition factor 1.13 and reduction factor 0.98 under water connote.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.3
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• pp.25-37
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• 2013

The purpose of this study is to draw reasonable management plans to reinforce essence of Ohyundan(五賢壇: Five sprit tablets), a sacred site and monument of Jeju, by investigating and analyzing current status and problems of cultural landscape elements(e.g. architectural structures, installation, letters carved on the rocks, actual vegetation, etc.) while grasping placeness contained in Ohyundan through consideration of its history and transition process of Ohyundan a future being and shrine of Gyulrim Seowon(橘林書院) in Jeju. Results derived from research are summarized as follows. Ohyundan is noted due to its placeness in that it was a place for Gyulrim Seowon, Jeju's one and only Saaek Seowon(賜額書 院) and it was a symbolic space of exile culture in Jeju. As it is inferred from Gyulrim Seowon, which is dangho(堂號: clan name) of Seowon, orchards surrounding all over places are a signature landscape element that shows placeness of the past Ohyundan. Joduseok(俎豆石: altar stone), representing a core installation of Ohyundan and ancestral tablet of five spirits, created a refined place by putting up common stones around altar and founding blocked stones to wall. This refinement and thrift served basic mind of Neo-Confucianism, and led to of Jeju's Jonyang mind(spend-thrift mind). In conclusion, a practice plan is a prerequisite to restore essence of Ohyundan by actively excluding installations not suitable for placeness or overly designed such as Jeju Hyangrodang(a center for the elderly) and numerous monument houses. On the other hand, together with Joduseok, as letters carved on the rocks such as 'Jeungjoo Byukrip(曾朱壁立)' and 'Gwangpoongdae(光風臺)' and Yoocheonseok serve as a signature landscape that well shows mind of five spirits and teaching of Neo-Confucianism, and also a trace from a confucian viewpoint deeply rooted in Jeju, they are judged as a cultural landscape corresponding to the essence of place in Ohyundan which requires proactive preservation and plans for public relations. Together with this, although many different old big trees such as Pinus densiflora , Pinus thunbergii, Quercus variabilis, Celtis sinenis, Zelkova serrata and Rhus succedanea are a landscape element that increases sacred Ohyundan and commemorative value, now required is thorough entity tree management by assigning serial number on them as many of them were dead or removed resulting from transition process of land use. Further, to reinforce quality of site location belonging to Gyulrim Seowon, a prerequsite is to review plans that create Gyulrim at reinstalled site of building and raw land.

• Journal of the Korea Concrete Institute
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• v.21 no.4
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• pp.531-537
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• 2009

In this study alkali reactivity of crushed stone was conducted according to the ASTM C 227 that is traditional mortar bar test, and C 1260 that is accelerated mortar bar test method. The morphology and chemical composition of products formed in mortar bar, 3 years after the mortar bar tests had been performed, were examined using scanning electron microscopy (SEM) with secondary electron imaging (SEI) and electron probe microanalysis (EPMA) with backscattered electron imaging (BSEI). The crushed stone used in this study was not identified as being reactive by ASTM C 227. However, mortar bars exceeded the limit for deleterious expansion in accelerated mortar bar test used KOH solution. The result of SEM (SEI) analysis, after the ASTM C 227 mortar bar test, confirmed that there were no reactive products and evidence of reaction between aggregate particles and cement paste. However, mortar bars exposed to alkali solution (KOH) indicated that crystallized products having rosette morphology were observed in the interior wall of pores. EPMA results of mortar bar by ASTM C 227 indicated that white dots were observed on the surface of particles and these products were identified as Al-ASR gels. It can be considered that the mortar bar by ASTM C 227 started to appear sign of alkali-silica reaction in normal condition. EPMA results of the mortar bar by ASTM C 1260 showed the gel accumulated in the pores and diffused in to the cement matrix through cracks, and gel in the pores were found to be richer in calcium compared to gel in cracks within aggregate particles. In this experimental study, damages to mortar bars due to alkali-silica reaction (ASR) were observed. Due to the increasing needs of crushed stones, it is considered that specifications and guidelines to prevent ASR in new concrete should be developed.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.3
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• pp.154-167
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• 2014

The results of this study conducted to identify the substance, regional characteristics or landscaping of Namwon Yonghogugok, which is the only valley of Jiri Mountain, based on Kim Samun's 'Yonghokugok-Gyeongseungannae(龍湖九曲景勝案內)', 'Yongseongji(龍城誌)' and position, meaning of letters carved and projection technique by ArcGIS10.0 on the rocks are as below. The feature landscapes of the canyon of Yonghogugok, which is an incised meander and one of the Eight beautiful scenery of Namwon, ponds, cliffs and rocks generated with metamorphic rocks and granites weathered by rapids torrents. As a result of measuring the GPS coordinates of the letters carved on the rocks, excluding the 3 Gok Hakseoam and the distances based on the origin and destination of the letters carved on the rocks using the API(Application Programming Interface) function of Daum map, the total distance of Yonghogugok was 3.5km and the average distance between the each Gok was 436.5m. It is assumed that Yonghogugok was designated by Sarim(士林) of the Kiho School(畿湖學派) related to Wondong Hyangyak(元洞鄕約) which is the main agent of Yonghojeongsa(龍湖精舍), the forerunner of Yonghoseowon(龍湖書院), between the late Joseon Dynasty and the early Japanese colonial era, in 1927. Its grounds are the existence of Yonghoyeongdang mentioned on 'Yonghojeongsilgi'(龍湖亭實記), records of 'Haeunyugo(荷隱遺稿)', 'Yonghopumje(龍湖品題)' of Bulshindang(佛神堂), 'Yonghojeongsadonggu Gapjachun(龍湖精舍洞口 甲子春)' letters carved on the rocks and 'Yonghogugok-Shipyeong(龍湖九曲十詠)' posted on Mokgandang of Yonghoseowon. Comprehensively considering the numerous poetry society lists carved on the stone wall of Punghodae(風乎臺), the Sixth Gok Yuseondae, its stone mortar, 'Bangjangjeildongcheon(方丈第一洞天)' of Bulshindang and Gyoryongdam(交龍潭), the Yonghoseokmun(龍湖石門) letters carved on the rocks, Yeogungseok adjacent to the First Gok and Fengshui facilities, centered on Yonghoseowon and Yonghojeong, Yonghogugok can be understood as a unique valley culture formed with the thoughts of Confucianism, Buddhism, Taoism and Fengshui. 'Yonghogugok-Gyeongseungannae' provides very useful information to understand the place name, called by locals and landscaping aspects of Yonghogugok in the late Joseon Dynasty. In addition, the meaning of "Nine dragons" and even though 12 chu(湫: pond) of Yonghogugok Yongchudong including Bulyeongchu, Guryongchu, Isuchu, Goieumchu and Daeyachu are mentioned on Yongseongji, a part of them cannot be confirmed now. Various place names and facilities relevant to Guryong adjacent to Yonghogugok are the core of the place identity. In addition, the accurate location identification and the delivery of the landscaping significance of the 12 ponds is expected to provide landscaping attractiveness of Yonghogugok and become very useful contents for landscaping storytelling and a keyword of storyboard.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.4
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• pp.75-87
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• 2017

This study is the research about Okcheonjeong(玉泉亭) located in the backyard of Namhansanseong(南漢山城)'s temporary palace(行宮). Okcheonjeong was not only built by a government inside Namhansanseong but it was also representative garden which is shown the culture of the nobility. It became famous garden ruins recently because it has remained many carved stones. However, there has been no study about Okcheonjeong yet. We studied Okcheonjeong to establish basic knowledge by literature analysis and field investigation. We tried to discover garden style by deciphering carved stones, and estimate Okcheonjeong's location by documentary research. Sim, Sang-Gyu became Gwangjuyusu(廣州留守) in 1816, and he built Okcheonjeong on the backyard of Namhansanseong's temporary palace in 1817. It was located in the foot of a mountain beside a stream. It consisted of Pungaepok(楓靄瀑: waterfall), Chusudam(秋水潭: a little pond), and Okcheon(玉泉: a stone wall). The stone for sign stands in front of the entrance of Pungaepok to show Okcheonjeong, and there is Yeongyeondae(泠然臺) above the waterfall. We thought that Okcheonjeong was typical Imcheon-garden(林泉庭苑). Okcheonjeong is located in the foot of a mountain following Gamigyeong(歌薇逕) 60 meters so it was able to see the whole temporary palace from the Okcheonjeong. It was the garden pavilion of temporary palace, but it was used in semi public garden(半公的庭苑). Okcheonjeong is the only graden ruins which was located in Namhansanseong, so we have to preserve as cultural heritage. We expect to make use of primary datas to restore Namhansanseong soundly which was world heritage.

• Journal of agriculture & life science
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• v.45 no.2
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• pp.69-83
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• 2011

The aim of the research was to provide basic information for a suitable management and utilization of protected trees by law. To achieve this aim, this study investigated the current state, management status and utilization of protected trees by law in Gyeongsan city. The result of the current state of protected trees indicated that there were 55 protected trees designated since 1982. These trees consisted of 8 species which were located at 41 places. Major species was Sophora japonica (30.9%), followed by Zelkova serrata (23.6%). The protected trees have been used as sacred trees (45.5%) in the villages, followed by scenic trees (36.7%). 38.2% of the protected trees were 200 to 300 years old and 54.6% of the trees were 15 to 30 m in height. 34% of the protected trees were located in the villages, followed by beside road (19.5%). Single trees (78%) were mostly planted. The result of the management status indicated that 58.5% of the root area in protected trees were covered with bare ground, followed by gravel mulch (19.5%). The average of soil hardness was 9.64 mm. The safety fence of tree was installed at 9 places (22%) and a stone wall was built at 22 places (53.7%). 70.9% of the protected trees had a surgical operation to prevent cavities and to cure decay. Granite stone signs were installed at 33 places. The result of the utilization of protected trees indicated that 13 places were used as a rest area in the villages. It consisted of shelters, benches, athletic facilities and outdoor tables. The research suggested potential places for a mini park(pocket park) to recover a local community by using surrounding available land and improving current rest areas of protected trees. The research presented here is a first step towards a more comprehensive analysis of protected trees in Gyeongsan and further research is needed.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.170-181
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• 2011

This Research will explore the meaning indicated in the landscape meaning and feature of literary group culture, focusing in Gurujeong(九老亭: pavilion for nine elders) and Samgaeseokmun(三溪石門: stone gate in three valleys) located in Dundeok-myun, Imshil-gun, and will seek to understand the implications by studying the cultural landscape spread out in the area. The place where Gurojeong and Samgaeseokmun is located is the meeting point of the three valleys, Dunnam stream, Osu stream, and Yul stream, which is the main location to view the beautiful scenery, which has the nickname as the dwelling place of a celestial being. Especially, based on the description of old maps, "Samgae(three valleys)" and "Samgaeseokmun" possesses significance as a landmark and shows a characteristic feature of landscape structures of low hills. Dangugurohwe(丹丘九老會: nine elders gathering on the dwelling of a celestial being) originated from Hyangsangurohwe(香山九老會: gathering of nine elders on a fragrant mountain), where Baekgeoi(白居易) of China was one of the main people. This group was organized by nine elders over the age of 60 desiring to view the scenery of Doyeonmyeong. The group enhanced the literary spirit on the low hill, erecting a tower, and enjoying the beautiful scenery changing every season with scholars from the same region. This phenomenon seems to have been formed upon the positive response to gatherings of elders, which were prevalent in the Joseon Dynasty. If the internal idea pursued by the group was "longevity," the external idea pursued can be summarized as "the spirit the respect for the elders." Naming the groups as 'Dangudae(place where the celestial being lives), Guseondong(valley of seeking a celestial life), Bangjangsan(mountain of a high priest), and Daecheondae(place of communicating with God) was likely a device to introspect oneself and symbolize one's life process. Furthermore, the reason Samgaeseokmun, which is an imitation of Choi, Chiwon's work, was built near Soyocheo, was probably to yearn the celestial land and based on the desire to follow Choi, Chiwon, who was the most self-fulfilling being presumed to have become a celestial being by practicing the pursuit of freedom, escaping from the reality. After tracing the symbolizing meaning of the four letters carved in the left side of the stone wall of Dangudae, the conclusion that this place was not only a place for literary gatherings of the nine elders of Saseong(four families), but was a place where the celestial being dwelled could be inferred. Corresponding with Dangudae and Gurojeong, which are places where the order of human and nature is harmonized and where its meaning associated with the location intensifies, arouses strong bond, can be said to be the symbol of the traces of celestial beings where the spirits of attachment to a certain place is embedded. The acts performed in Dangugurohwe were those of traditional leisure including strolling, viewing the scenery, drinking, composing poems, and playing instruments, and sometimes listening to stories, tea ceremony, prayers, and fishing were added, which indicates that the gathering had a strong tendency towards pastoral and hermit life.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.25-38
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• 2020

For the purpose of recording Folk House Garden, this study was to review the historical value, location, space composition, Placememnt of the Building, garden composition, and management status of Folk House Garden designated as a cultural asset in Jeolla-do and to promote continuous maintenance and preservation in the future and enhance its value. The results of the study are as follows. First, most of them have been influenced by the trend of the times, such as the creation of a modern private garden and the spread of agricultural and commercial development through the garden components influenced by the royal, Japanese, and Western styles. Second, there are differences in the spatial composition of private households and the way they handle sponsorship, depending on the geographical location. When the geographical features were divided into flat and sloping areas, private houses located on flat land were divided into walls, walls were placed around the support area, and flower systems and stone blocks were created. The private houses located on the slope were divided into two to three tiers of space, and the wooden plant, flower bed, and stone bed were naturally connected to the background forest without creating a wall at the rear hill. Third, the size of the house and the elements of the garden have been partially destroyed, damaged, and changed, and if there is a lack of records of the change process, there is a limit to the drawing floor plan. There were many buildings and garden components that were lost or damaged due to changes in the trend and demand of the times, and some of them without records had to rely on the memory of owners and managers. Fourth, the species in Warm Temperate Zone, which reflects the climatic characteristics of Jeolla-do, was produced, and many of the exotic species, not traditional ones, were introduced. Fifth, fine-grained tree management standards are needed to prepare for changes in spatial function and plant species considering modern convenience.

• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.176-181
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• 2017

PURPOSE. The purpose of this study was to evaluate the marginal and internal gaps of Ni-Cr and Co-Cr copings, fabricated using the dental ${\mu}-SLA$ system. MATERIALS AND METHODS. Ten study dies were made using a two-step silicone impression with a dental stone (type IV) from the master die of a tooth. Ni-Cr (NC group) and Co-Cr (CC group) alloy copings were designed using a dental scanner, CAD software, resin coping, and casting process. In addition, 10 Ni-Cr alloy copings were manufactured using the lost-wax technique (LW group). The marginal and internal gaps in the 3 groups were measured using a digital microscope ($160{\times}$) with the silicone replica technique, and the obtained data were analyzed using the non-parametric Kruskal-Wallis H test. Post-hoc comparisons were performed using Bonferroni-corrected Mann-Whitney U tests (${\alpha}=.05$). RESULTS. The mean (${\pm}$ standard deviation) values of the marginal, chamfer, axial wall, and occlusal gaps in the 3 groups were as follows: $81.5{\pm}73.8$, $98.1{\pm}76.1$, $87.1{\pm}44.8$, and $146.8{\pm}78.7{\mu}m$ in the LW group; $76.8{\pm}48.0$, $141.7{\pm}57.1$, $80.7{\pm}47.5$, and $194.69{\pm}63.8{\mu}m$ in the NC group; and $124.2{\pm}52.0$, $199.5{\pm}71.0$, $67.1{\pm}37.6$, and $244.5{\pm}58.9{\mu}m$ in the CC group. CONCLUSION. The marginal gap in the LW and NC groups were clinically acceptable. Further improvement is needed for CC group to be used clinical practice.

• Journal of the Korean association of regional geographers
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• v.6 no.1
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• pp.51-68
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• 2000

The Sacheon bay region functioned as a strategic place as the bay provided a major sea-route leading to the Kyungnam province. So it is no wonder that a number of castles and walls were located in such an outlying post of strategic importance. In the bay region there are found Sacheon, Gonyang and Seonghwangdang town castles, Yeegu, Seongbangri, Shinbyukdong, Duckgockri, Baekcheondong and Gaksan miltary castles, Seonjinri and Sadung Japanese castles, Kumseonri and Wueolseongri mud walls, Gaksan, Anjeom, Chimzi and Usan beacon-post walls, and Tongyang, Gasan and Jangam warehouse walls(사천읍성, 곤양읍성, 성황당산성, 이구산성, 성방리산성, 신벽동산성, 덕곡리산성, 백천동산성, 각산산성, 사등산성지, 선진리성, 금성리 토성, 월성리 토성지, 각산봉수대성, 안점봉수대성, 침지봉수대성지, 우산봉수대성, 통양창성지, 가산창성지, 장암창성). Castles are, according to their functions, classified into two: town castles and military castles. In the former castles people live permanently, but in the latter people do not. Military castles are occupied only in time of emergence. Beside the two types, two Japanese castles, two old mud walls, four beacon-post walls, and three warehouse-post walls are found in the Sacheon bay region. Castles are also classified into plain castles and mountain castles according to their location. Mud, stone, wood, and brick materials were used for castle and wall building. As the castles and walls of the bay region are precious cultural assets, they should be preserved and protected with much attention. It should be remembered that in the future they can be the most valuable tourist attractions all around.