• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.333-340
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• 2015

Because soils in reclaimed lands nearby coastal areas have much higher salinity and moisture content than soils in inland area, parts of greenhouses embedded in such soils are exposed to highly corrosive environments. Owing to the accelerated corrosion of galvanized steel pipes for substrucrture and structure of greenhouses in saline environments, repair and reinforcement technologies and efficient maintenance and management for the construction materials in such facilities are required. In this study, we measured the corrosion rates of the parts used for greenhouse construction that are exposed to the saline environment to obtain a basic database for the establishment of maintenance and reinforcement standards for greenhouse construction in reclaimed lands with soils with high salinity. All the test pipes were exposed to soil and water environments with 0, 0.1, 0.3, and 0.5% salinity during the observation period of 480 days. At the end of the observation period, salinity-dependent differences of corrosion rate between black-surface corrosion and relatively regular corrosion were clearly manifested in a visual assessment. For the soils in rice paddies, the corrosion growth rate increased with salinity (0.008, 0.027, 0.036, and $0.043mm{\cdot}yr^{-1}$ at 0, 0.1, 0.3, and 0.5% salinity, respectively). The results for the soils in agricultural fields are 0.0002, 0.039, 0.040, and $0.039mm{\cdot}yr^{-1}$ at 0, 0.1, 0.3, and 0.5% salinity, respectively. The higher corrosion rate of rice-paddy soil was associated with the relatively high proportion of fine particles in it, reflecting the general tendency of soils with evenly distributed fine particles. Hence, it was concluded that thorough measures should be taken to counteract pipe corrosion, given that besides high salinity, the soils in reclaimed lands are expected to have a higher proportion of fine particles than those in inland rice paddies and agricultural fields.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.275-283
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• 2007

This study was carried out to: (1) analyze structural stability of representative rain-sheltering greenhouses for large-grain grapevine cultivation with widths of 3.6 m and 5 m in case of using the existing pipe for agriculture; (2) present the optimum specification of pipes in the greenhouse with a width of 5 m under the condition of using the pipe of which ultimate strength has been above $400N{\cdot}mm^{-2}$; (3) evaluate stability and also present the optimum specification of pipes as eaves height was augmented. The above analyses were done for greenhouses with roof vents and also with a main-column interval of 3 m and a rafter interval of 60 cm. First, the existing 3.6 m greenhouse with a rafter of ${\Phi}25.4{\times}1.5t@600$ was stable far a snow-depth of 35 cm but unstable for a wind velocity of $35m{\cdot}s^{-1}$. Meanwhile the existing 5 m greenhouse with the same rafter was not stable for a wind velocity of $335m{\cdot}s^{-1}$ as well as a snow-depth of 35 cm. This meant that existing greenhouses had to be reinforced to secure stability. Second, the specification of pipes, especially rafter, could be classified as two cases. One had a structural stability at a safe wind velocity of $35m{\cdot}s^{-1}$ and a safe snow-depth of 40 cm for which stability the rafter had to be ${\Phi}31.8{\times}1.5t@600$, and the other had a stability at $30m{\cdot}s^{-1}-35cm$ at the specification of rafter ${\Phi}25.4{\times}1.5t@600$. Finally, eaves height had a significant effect on safe wind velocity. But it had little influence on safe snow-depth. The results showed that the specification of side-wall pipes had to be reinforced for the safe side velocity accord-ing to the increment of eaves height and similarly the specification of fore-end post far the safe fore-end velocity.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.94-101
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• 2015

To mitigate the greenhouse gas emission, many carbon capture and storage projects are underway all over the world. In Korea, many studies focus on the storage of $CO_2$ in the offshore sediment. Assurance of safety is one of the most important issues in the geological storage of $CO_2$. Especially, the assessment of possibility of leakage and amount of leaked $CO_2$ is very crucial to analyze the safety of marine geological storage of $CO_2$. In this study, the leakage of injected $CO_2$ through fault was numerically studied. TOUGH2-MP ECO2N was used to simulate the subsurface behavior of injected $CO_2$. The storage site was 150 m thick saline aquifer located 825 m under the continental shelf. It was assumed that $CO_2$ leak was happened through the fault located 1,000 m away from the injection well. The injected $CO_2$ could migrate through the aquifer by both pressure difference driven by injection and buoyancy force. The enough pressure differences made it possible the $CO_2$ to migrate to the bottom of the fault. The $CO_2$ could be leaked to seabed through the fault due to the buoyancy force. Prior to leakage of the injected $CO_2$, the formation water leaked to seabed. When $CO_2$ reached the seabed, leakage of formation water stopped but the same amount of sea water starts to flow into the underground as the amount of leaked $CO_2$. To analyze the effect of injection rate on the leakage behavior, the injection rate of $CO_2$ was varied as 0.5, 0.75, and $1MtCO_2/year$. The starting times of leakage at 1, 0.75 and $0.5MtCO_2/year$ injection rates are 11.3, 15.6 and 23.2 years after the injection, respectively. The leakage of $CO_2$ to the seabed continued for a period time after the end of $CO_2$ injection. The ratios of total leaked $CO_2$ to total injected $CO_2$ at 1, 0.75 and $0.5MtCO_2/year$ injection rates are 19.5%, 11.5% and 2.8%, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.473-479
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• 2012

Water reuse has been highlighted as a representative alternative to solve the lacking water resource. This study carried out a study on the pipe corrosion and water quality change which can occur through the supply of reclaimed water, using a simulated reclaimed water distribution pipeline. Galvanized steel pipe (GSP), cast iron pipe (CIP), stainless steel pipe (STSP) and PVC pipe (PVCP) were used for the pipe materials. Reclaimed water(RW) and tap water(TW) were respectively supplied into simulated reclaimed water distribution pipelines. As a result of performing a loop test to supply reclaimed water to simulated reclaimed water distribution pipelines, the weight reduction of pipe coupons showed the sequence of CIP > GSP > STSP ${\approx}$ PVCP. In addition, reclaimed water showed a high corrosion rate comparing to that of tap water. In case of CIP, the initial corrosion rate showed 3.511 mdd(milligrams per square decimeter per day) for reclaimed water and 2.064 mdd for tap water and the corrosion rate for 90 days showed 0.833 mdd for reclaimed water and 0.294 mdd for tap water. Also in case of GSP, the initial corrosion rate showed 2.703 mdd for reclaimed water and 2.499 mdd for tap water and the corrosion rate for 90 days showed 0.349 mdd for reclaimed water and 0.248 mdd for tap water, which was a tendency similar to that appeared in CIP with a tendency to reduce the corrosion rate. As a result of water quality changes of reclaimed water at pipe materials to carry out the loop test, there was higher conversion ratio of ammonia into nitrate in CIP and GSP with higher corrosion rate than that in STSP and PVCP where no corrosion has occurred. The highest denitrification rate of nitrate could be observed from CIP with the most particles generated from corrosion. In CIP, it could be confirmed that there was MIC (Microbiologically Induced Corrosion) as a result of EDS (Energy Dispersive X-ray spectrometer System) analysis results.

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.71-82
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• 2006

One of the most popular pre-reinforcement methods of tunnel heading in cohesionless soils would be the fore-polling of grouted pipes, known as RPUM (reinforced protective umbrella method) or UAM (umbrella arch method). This technique allows safe excavation even in poor ground conditions by creating longitudinal arch parallel to the tunnel axis as the tunnel advances. Some previous studies on the reinforcing effects have been performed using numerical methods and/or laboratory-based small scale model tests. The complexity of boundary conditions imposes difficulties in representing the tunnelling procedure in laboratory tests and theoretical approaches. Full-scale study to identify reinforcing effects of the tunnel heading has rarely been carried out so far. In this study, a large scale model testing for a tunnel in granular soils was performed. Reinforcing patterns considered are four cases, Non-Reinforced, Crown-Reinforced, Crown & Face-Reinforced, and Face-Reinforced. The behavior of ground and pipes as reinforcing member were fully measured as the surcharge pressure applied. The influences of reinforcing pattern, pipe length, and face reinforcement were investigated in terms of stress and displacement. It is revealed that only the Face-Reinforced has decreased sufficiently both vertical settlement in tunnel heading and horizontal displacement on the face. Vertical stresses along the tunnel axis were concentrated in tunnel heading from the test results, so the heading should be reinforced before tunnel advancing. Most of maximum axial forces and bending moments for Crown-reinforced were measured at 0.75D from the face. Also it should be recommended that the minimum length of the pipe is more than l.0D for crown reinforcement.

• MISULJARYO - National Museum of Korea Art Journal
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• v.96
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• pp.155-180
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• 2019

Samsaebulhoedo(三世佛會圖) at Yongjusa Temple(龍珠寺), regarded as a monumental masterpiece consisting of different elements such as Confucian and Buddhist ideas, palace academy garden and Buddhist artist styles, unique traditional and western painting styles, is one of the representative works that symbolically illustrate the development and innovation of painting in the late Joseon dynasty. However, the absence of painting inscriptions raised persistent controversy over the past half century among researchers as to the matters of estimating its production period, identifying the original author and analyzing style characteristics. In the end, the work failed to gain recognitions commensurate with its historical significance and value. It is the particularly vital issue in that estimating the production period of the existing masterpiece is the beginning of all other discussions. However, this issue has caused the ensuing debates since all details are difficult to be interpreted to a concise form due to a number of different records on painters and mixture of traditional buddhist painting styles used by buddhist painters and innovative western styles used by ordinary painters. Contrary to other ordinary Buddhist paintings, this painting, Samsaebulhoedo, has a praying letter for the royal establishment at the center of the main altar. It should be noted that regarding this painting, its original version-His Royal Highness King, Her Majesty, His Royal Crown Prince主上殿下, 王妃殿下, 世子邸下-was erased and instead added Her Love Majesty慈宮邸下 in front of Her Majesty. This praying letter can be assumed as one of the significant and objective evidence for estimating its production period. The new argument of the late 19th century production focused on this praying letter, and proposed that King Sunjo was then the first-born son when Yongjusa Temple was built in 1790 and it was not until January 1, 1800 that he was ascended to the Crown Prince. In this light, the existing praying letter with the eulogistic title-Crown Prince世子-should be considered revised after his ascension to the throne. Styles and icons bore some resemblance to Samsaebulhoedo at Cheongryongsa Temple or Bongeunsa Temple portrayed by Buddhist painters in the late 19th century. Therefore, the remaining Samsaebulhoedo should be depicted by them in the same period as western styles were introduced in Buddhist painting in later days. Following extensive investigations, praying letters in Buddhist paintings in the late 19th century show that it was usual to record specification such as class, birth date and family name of people during the dynasty at the point of producing Buddhist paintings. It is easy to find that those who passed away decades ago cannot be revised to use eulogistic titles as seen by the praying letters in Samsaebulhoedo at Yongju Temple. As "His Royal Highness King, Her Majesty, His Royal Crown Prince" was generally used around 1790 regardless of the presence of first-born son or Crown Prince, it was rather natural to write the eulogistic title "His Royal Crown Prince" in the praying letter of Samsaebulhoedo. Contrary to ordinary royal hierarchy, Her Love Majesty was placed in front of Her Majesty. Based on this, the praying letter was assumed to be revised since King Jeongjo placed royal status of Hyegyeonggung before the Queen, which was an exceptional case during King Jeongjo's reign, due to unusual relationships among King Jeongjo, Hyegyeonggung and the Queen arising from the death of Crown Prince(思悼世子). At that time, there was a special case of originally writing a formal tripod praying letter, as can be seen from ordinary praying letter in Buddhist paintings, erasing it and adding a special eulogistic title: Her Love Majesty. This indicates that King Jeongjo identified that Hyegyeonggung was erased, and commanded to add it; nevertheless, ceremony leaders of Yongju Temple, built as a palace for holding ceremonies of Hyeonryungwon(顯隆園) are Jeongjo, the son of his father and his wife Hyegyeonggung (Her Love Majesty)(惠慶宮(慈宮)). This revision is believed to be ordered by King Jeongjo on January 17, 1791 when the King paid his first visit to the Hyeonryungwon since the establishment of Hyeonryungwon and Yongju Temple, stopped by Yongju Temple on his way to palace and saw Samsaebulhoedo for the first and last time. As shown above, this letter consisting of special contents and forms can be seen an obvious, objective testament to the original of Samsebulhoedo painted in 1790 when Yongju Temple was built.

• MISULJARYO - National Museum of Korea Art Journal
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• v.97
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• pp.14-54
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• 2020

The overall study of Samsaebulhoedo (painting of the Assembly of Buddhas of Three Ages) at Yongjusa Temple has focused on dating it, analyzing the painting style, identifying its painter, and scrutinizing the related documents. However, its greater coherence could be achieved through additional support from empirical evidence and logical consistency. Recent studies on Samsaebulhoedo at Yongjusa Temple that postulate that the painting could have been produced by a monk-painter in the late nineteenth century and that an original version produced in 1790 could have been retouched by a painter in the 1920s using a Western painting style lack such empirical proof and logic. Although King Jeongjo's son was not yet installed as crown prince, the Samsaebulhoedo at Yongjusa Temple contained a conventional written prayer wishing for a long life for the king, queen, and crown prince: "May his majesty the King live long / May her majesty the Queen live long / May his highness the Crown Prince live long" (主上殿下壽萬歲, 王妃殿下壽萬歲, 世子邸下壽萬歲). Later, this phrase was erased using cinnabar and revised to include unusual content in an exceptional order: "May his majesty the King live long / May his highness the King's Affectionate Mother (Jagung) live long / May her majesty the Queen live long / May his highness the Crown Prince live long" (主上殿下壽萬歲, 慈宮邸下壽萬歲, 王妃殿下壽萬歲, 世子邸下壽萬歲). A comprehensive comparison of the formats and contents in written prayers found on late Joseon Buddhist paintings and a careful analysis of royal liturgy during the reign of King Jeongjo reveal Samsaebulhoedo at Yongjusa Temple to be an original version produced at the time of the founding of Yongjusa Temple in 1790. According to a comparative analysis of formats, iconography, styles, aesthetic sensibilities, and techniques found in Buddhist paintings and paintings by Joseon court painters from the eighteenth and nineteenth centuries, Samsaebulhoedo at Yongjusa Temple bears features characteristic of paintings produced around 1790, which corresponds to the result of analysis on the written prayer. Buddhist paintings created up to the early eighteenth century show deities with their sizes determined by their religious status and a two-dimensional conceptual composition based on the traditional perspective of depicting close objects in the lower section and distant objects above. This Samsaebulhoedo, however, systematically places the Buddhist deities within a threedimensional space constructed by applying a linear perspective. Through the extensive employment of chiaroscuro as found in Western painting, it expresses white highlights and shadows, evoking a feeling that the magnificent world of the Buddhas of the Three Ages actually unfolds in front of viewers. Since the inner order of a linear perspective and the outer illusion of chiaroscuro shading are intimately related to each other, it is difficult to believe that the white highlights were a later addition. Moreover, the creative convergence of highly-developed Western painting style and techniques that is on display in this Samsaebulhoedo could only have been achieved by late-Joseon court painters working during the reign of King Jeongjo, including Kim Hongdo, Yi Myeong-gi, and Kim Deuksin. Deungun, the head monk of Yongjusa Temple, wrote Yongjusa sajeok (History of Yongjusa Temple) by compiling the historical records on the temple that had been transmitted since its founding. In Yongjusa sajeok, Deungun recorded that Kim Hongdo painted Samsaebulhoedo as if it were a historical fact. The Joseon royal court's official records, Ilseongnok (Daily Records of the Royal Court and Important Officials) and Suwonbu jiryeong deungnok (Suwon Construction Records), indicate that Kim Hongdo, Yi Myeong-gi, and Kim Deuksin all served as a supervisor (gamdong) for the production of Buddhist paintings. Since within Joseon's hierarchical administrative system it was considered improper to allow court painters of government position to create Buddhist paintings which had previously been produced by monk-painters, they were appointed as gamdong in name only to avoid a political liability. In reality, court painters were ordered to create Buddhist paintings. During their reigns, King Yeongjo and King Jeongjo summoned the literati painters Jo Yeongseok and Kang Sehwang to serve as gamdong for the production of royal portraits and requested that they paint these portraits as well. Thus, the boundary between the concept of supervision and that of painting occasionally blurred. Supervision did not completely preclude painting, and a gamdong could also serve as a painter. In this light, the historical records in Yongjusa sajeok are not inconsistent with those in Ilseongnok, Suwonbu jiryeong deungnok, and a prayer written by Hwang Deok-sun, which was found inside the canopy in Daeungjeon Hall at Yongjusa Temple. These records provided the same content in different forms as required for their purposes and according to the context. This approach to the Samsaebulhoedo at Yongjusa Temple will lead to a more coherent explanation of dating the painting, analyzing its style, identifying its painter, and interpreting the relevant documents based on empirical grounds and logical consistency.