• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.31-48
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• 2019

The artificial ground freezing (AGF) method is a groundwater cutoff and/or ground reinforcement method suitable for constructing underground structures in soft ground and urban areas. The AGF method conducts a freezing process by employing a refrigerant circulating through a set of embedded freezing pipes to form frozen walls serving as excavation supports and/or cutoff walls. However, thermal expansion of the pore water during freezing may cause excessive deformation of the ground. On the other hand, as the frozen soil is thawed after completion of the construction, mechanical characteristics of the thawed soil are changed due to the plastic deformation of the ground and the rearrangement of soil fabric. This paper performed a field experiment to evaluate the freezing rate of marine clay in the application of the AGF method. The field experiment was carried out by circulating liquid nitrogen, which is a cryogenic refrigerant, through one freezing pipe installed at a depth of 3.2 m in the ground. Also, a piezo-cone penetration test (CPTu) and a lateral load test (LLT) were performed on the marine clay before and after application of the AGF method to evaluate a change in strength and stiffness of it, which was induced by freezing-thawing. The experimental results indicate that about 11.9 tons of liquid nitrogen were consumed for 3.5 days to form a cylindrical frozen body with a volume of about $2.12m^3$. In addition, the strength and stiffness of the ground were reduced by 48.5% and 22.7%, respectively, after a freezing-thawing cycle.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.109-122
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• 2022

Currently, most of the pig manure generated from pig farms in Korea is in the form of a slurry with a moisture content of about 97%. Pig manure slurry is a mixture of pig manure and cleaning water in the pig house. In this study, changes in properties of pig manure liquid fertilizer according to whether air was supplied or not and with the passage of storage period were analyzed for 120 days. During the experimental period, the degree of maturity of the pig manure liquid fertilizer was higher in the experimental closed batch reactors supplied with air than in the same type reactors not supplied with air. As the liquid fertilizer storage period elapsed, there was a tendency that liquid fertilizer was converted to a state of complete maturity. In the batch reactor in which air was supplied, the moisture content of pig manure slurry, which had a moisture content of 97.90%, was reduced to 96.82% at the end of the experiment. On the other hand, the moisture content in the reactor without air was reduced to 97.33%. The pH of the liquid fertilizer, which was 8.82 at the start of the experiment, changed to 7.57 in the reactor with air supplied and 8.75 in the reactor without air at the completion of the experiment. The nitrogen content in the liquid fertilizer was 0.198 mg/L on average at the start of the experiment and it was lowered to 0.076 mg/L in the air supplied reactor at the end of the experiment. On the other hand, the nitrogen content of the liquid fertilizer was lowered to 0.121 mg/L in the reactor to which air was not supplied. The phosphoric acid (P₂O₅) concentration in the liquid decreased higher in the liquid fertilizer filled in the reactor without air than the liquid fertilizer filled in the reactor with air supplied as the storage period elapsed. Considering the experimental results, it is considered that the quality of pig manure liquid fertilizer is improved when air is supplied to pig manure slurry and the storage period of pig manure slurry is longer.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.27-39
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• 2011

The study on Musan twelve peaks of Yongho garden in Jinju, Gyeongnam was anticipated to provide data and implication for reproducing similar spaces and modern changes in terms of design factor since it is the prototype of traditional mount for overcoming monotonous geographical features and intriguing changes and interests. The study analyzed and interpreted the symbolism of twelve peaks, principles of space composition and function and effect of visual construction that were pursued by the builder in terms of landscape view, which results are as following. The center of Yongho garden, Yonghoji(龍虎池) is a typical man-made pond for a supportive feng shui feature. It is a supporting equipment to complete the state of feng shui, and the result of strengthening the completion through the connection with the dragon-related name of the place. The shape of Musan twelve peaks looks like an oval form of Geumseongsan(金星山), 2~3.5m in height and 6~12m in diameter. Peaks are estimated as 1.5~3.7m(2.4m in average) in height, $35{\sim}138m^2$($73.4m^2$ in average) in area, and $30.7{\sim}115.0m^3$($62.5m^3$ in average) in volume. Given that Yonghojeong(龍虎亭), Soseon(小船), the site of main building and Yongsanjae(龍山齋) stand in line, Yonghoji was presumed as the state of enlightenment through ascribing the meaning to virtue and secularity. For the intention of realizing Musan twelve peaks, the builder probably had mounted twelve peaks forming the body of dragons with crossing the point corresponding to a head of tiger, and located Musan twelve peaks and Yonghojeong with a representation of dragons holding Cintamani rising into the sky in the center. The middle area near Musan twelve peaks surrounded by peaks like Geumseongsan running north and south shows a multi-structure of multilayer, maintaining the similarity centering on Yonghoji. It is considered the intention of mount planned at the time of Musan twelve peaks construction, caused by similar form harmony. Internalization of progressive realization through concealment and exposure, enframement effect and spatial order like prospect-refuge theory in the mount of Musan twelve peaks is considered the reflection of the intention to increase depth of the view and expectancy through the various degree of exposure and surroundings of each peak and the colorful combination of viewing and shutting. The "closed view" by Musan twelve peaks creates interesting, vivid and attractive recognition of the view, which is more effective in bringing depth of the view and interests in terms of the geographical design, particularly the area around Yonghoji. Moreover, it was identified that the combination of peaks can be formed resulted from the view configuration concerning the location through multilayer effect reveals an island through the other one when viewed from Yonghojeong.

• The Journal of Korean Philosophical History
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• no.23
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• pp.295-316
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• 2008

This is to study the military philosophy of Wangzhen's Commentary on Daodejing written by a famous military officer in the end of Tang Dynasty, Wangzhen. Historically, many scholars consider Laozi's Daodejing as a book on military science. Wangzhen, however, is the only person to interpret Daodejing genealogically from a military perspective. Wangzhen thinks that the fact that human beings like competing naturally causes the constant competition in the world. Human beings are born with the most outstanding spirit among all beings. But, when God created human beings, they had greed and avarice in the middle of their heart. Accordingly, human beings look for a success and a profit, and follow the wicked way, leaving the right way. The contractions among each greed and avarice bring about small or big competitions. Human beings have greed and avarice. It means human beings have emotions. As a result, the competitions in the world are not able to disappear because human beings have emotions. To win the completion human beings use weapons. According to Wangzhen, the war is the most devilish deed due to the weapon's atrocious, dangerous quality. Yet, the world's interests are decided by how efficiently the weapons are used. Consequently, the weapon techniques are worthy and play an important role in the real world. Morality, however, should be in the first priority in ruling over a country and commanding the army. The national security and the war victory could be secured when civil and military affairs have a balance. Wangzhen thinks that Laozi emphasizes "Not-Competing" as a basic solution of competition. The competition is the root cause of war and disorder. Therefore, Not-Competing is the main idea of Daodejing. Not-Competiting is a basis of Wangzhen's military philosophy as well. For Wangzhen, Not-Competing is Wuwei. Wuwei has political and military meanings at the same time. Wangzhen build up the "Not-Competing" military philosophy by applying Loazi's Daodejing to his military philosophy.

• (The)Study of the Eastern Classic
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• no.49
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• pp.109-136
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• 2012

'Old man' or 'old age' was not the parts of academic discipline in the Joseon era but Yeoheon put it in the philosophical 'problematization' of the learning of the Confucianism. He was argued that the old man or old age is not merely biological decline but it has the goal to achieve. The completion of self is the meaning and end of the life throughout the subjective realization and procedure of attaining the goal step by step. Well-aged old man is affirming the getting old and making the positive changing of old life time in his one sake. This essay is showing the Yeoheon's thought of old aging as the self-realizing well-ageing. Next, it is argued that the predicament of old age or old man is not just social welfare or biological aspects but it is serious philosophical problems. If it was just social or biological aspects then it is just a social phenomenon to approach the view of scientists. However, this is not only life and death and flux of time and relativities but also it is problematizing the self-identification subjectivities. Obviously, it is the significant that the old and or old age is fundamentally philosophical subject rather than social or biological materials. In the third chapter, we are dealing with the views of the life and death of Yeoheon. He was insisted that quite interesting opinion that is the all the lives in the universe include himself is 'a wayfarer'. It looks like a time traveler in the universe; we are just one who stays in a body for awhile. When we follow him, we are living in this universe in a time (disposable) but the same theorem is applying to the whole universe as well myriad creatures. Therefore, man has a job to do as an entity of the universe. Yeoheon was called it is the business as a job and we have to do the Dao till you end. The fourth, Yeoheon was suggested that the old man has his work and business. There are two kind of works for an old man, the former is self control as an old age that is call the old man's job and the latter is staying with the Dao that is called the old man's business. According to Yeoheon, man has charged to realize the law of the universe that means we are the moral entity; therefore we are business to complete ourselves. Old age is decline of physical activities rather than vigorous, therefore, we have to follow our body and self-affirmation of declination is the Dao. The final, Yeoheon was advised that the old man better saved in the current of the Dao, because the physical function is declining but the shining Dao is within the mind in the body. It is motivation of the self-dignity of old man and one who recognizes the work to do even in the old body that he will be the significant among all the society not a lonely old man anymore. Old aging is biological twilight but the considerable real size expertise and self-affirmation is the Dao of old age. We are meditating nowadays in Yeoheon's philosophical context on old man or old aging. By him, the old age is man of dignity as long as he realizes in his Dao through the business and self-affirmation.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.12-28
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• 2021

Based on the global smart city promotion trend, in 2018, the "Fourth Industrial Revolution Committee" selected "sustainability" and "people-centered" as keywords in relation to the direction of domestic smart city policy. Accordingly, the Living Lab program, which is an active citizen-centered innovation methodology, is applied to each stage of the domestic smart city construction project. Through the Living Lab program, and in collaboration with the public and experts, the smart city discovers local issues as it focuses on citizens, devises solutions to sustainable urban problems, and formulates a regional development plan that reflects the needs of citizens. However, compared to citizen participation in urban regeneration projects that have been operated for a relatively long time, participation in smart city projects was found to significantly differ in level and sustainability. Therefore, this study conducted a comparative analysis of the characteristics of citizen participation at each stage of an urban regeneration project and, based on Arnstein's "Participation Ladder" model, examined the level of citizen participation activities in the Living Lab program carried out in a smart city commercial area from 2018 to 2019. The results indicated that citizen participation activities in the Living Lab conducted in the smart city project had a great influence on selecting smart city services, which fit the needs of local residents, and on determining the technological level of services appropriate to the region based on a relatively high level of authority, such as selection of smart city services or composition of solutions. However, most of the citizen participation activities were halted after the project's completion due to the one-off recruitment of citizen participation groups for the smart city construction project only. On the other hand, citizens' participation activities in the field of urban regeneration were focused on local communities, and continuous operation and management measures were being drawn from the project planning stage to the operation stage after the project was completed. This study presented a plan to revitalize citizen participation for the realization of a more sustainable smart city through a comparison of the characteristics and an examination of the level of citizen participation in such urban regeneration and smart city projects.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.727-736
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• 2021

Road tunnel lengths are increasing. Some 1,300 tunnels with 1,102 km in length had been increased till 2019 from 2010. There are 64 tunnels over 3,000 m in length, with their total length adding up to 276.7 km. Safety facilities in the event of a tunnel fire are critical so as to prevent large-scale casualties. Standards for installing disaster prevention facilities are being proposed based on the guidelines of the Ministry of Land, Infrastructure and Transport, but they may be limited to deep underground tunnels. This study was undertaken to provide guidelines for the spacing of evacuation connection passages and the widths of evacuation connection doors. Evacuation with various spacing and widths was simulated in regards to evacuation time, which is the measure of safety, using the evacuation analysis simulation software EXODUS Ver.6.3 and the fire/smoke analysis software SMARTFIRE Ver.4.1. Evacuation connection gates with widths of 0.9 m and 1.2 m, and spacings of 150 m to 250 m, were set to every 20 m. In addition, longitudinal slopes of 6 % and 0 % were considered. It was determined to be safe when the evacuation completion time was shorter than the delay diffusion time. According to the simulation results, all occupants could complete evacuation before smoke spread regardless of the width of the evacuation connection door when the longitudinal slope was 6 % and the interval of evacuation connection passage was 150 m. When the evacuation connection passage spacing was 200 m and the evacuation connection gate width was 1.2 m, all occupants could evacuate when the longitudinal slope was 0 %. Due to difference in evacuation speed according to the longitudinal slope, the evacuation time with a 6 % slope was 114 seconds shorter (with the 190 m connection passage) than with a 0 % slope. A shorter spacing of evacuation connection passages may reduce the evacuation time, but this is difficult to implement in practice because of economic and structural limitations. If the width of the evacuation junction is 1.2 m, occupants could evacuate faster than with a 0.9 m width. When the width of a connection door is 1.2 m with appropriate connection passage spacing, it might provide a means to increase economic efficiency and resolve structural limitations while securing evacuation safety.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.392-402
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• 2021

The present study investigated the effects of tillage practices (deep cultivation [DC] and conventional tillage [CT]) and extended planting dates (mid-June to July) for maize-onion rotation in paddy fields. The silage corn (Zea mays L.) cultivar 'Kwangpyeongok' and the waxy corn cultivar 'Ilmichal' were planted on June 14, July 3, and July 15 in 2019. In both maize, the plant height of June 14 planted was up to 100 cm greater than that of July 15 planted on August 16 and up to 40 cm on August 30. At 30 Days after planting, the leaf area index (LAI) of silage corn planted on July 3 and 15 greater than that of corn planted on June 14 due to high temperature in the early season; however, there were no differences in the LAI of waxy corn according to the planting date. Despite favorable temperature, plants sown on July 3 and 15 experienced high moisture stress during the seedling stage due to consistent rainfall, and waxy corn was highly sensitive to high moisture stress. The total yield of silage corn was 1,232 (845 in TDN), 860 (598 in TDN), and 765 (508 in TDN) DW kg·10a^-1 for plants sown on June 14, July 3, and July 15, respectively. The fresh marketable ear yield of waxy corn was 872, 814, and 525 FW kg·10a^-1 for plants sown on June 14, July 3, and July 15, respectively. After the completion of maize cultivation, onion seedlings (Allium cepa L.) were transplanted on November 12, 2019, and harvested on May 27, 2020. Neither summer tillage nor maize planting date affected onion growth or yield. The marketable onion yield was 8,305 and 7,848 kg·10a^-1 with DC and CT, respectively. In conclusion, DC did not improve maize growth or yield under paddy conditions. Mid-June to early July is a practical window for maize planting for growers in this region.

• Conservation Science in Museum
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• v.26
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• pp.25-34
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• 2021

3D printing technology has been actively applied for the restoration of cultural properties. However, its application to the restoration of glass cultural properties has not yet been reported and thus requires further study. In this study, 3D printing technology was used to restore a defective part of a glass sarira bottle that forms an element of a series of sarira reliquaries commissioned by Yi Seonggye (known as King Taejo after founding the Joseon Dynasty) that was excavated from Geumgangsan Mountain (designated as Treasure No. 1925) and is currently housed at the National Museum of Korea. The defective area was reproduced using 3D printing and the printed reproduction was reproduced again using an epoxy resin. This latter piece was used as the restoration component rather than the 3D printed element. After the completion of the conservation treatment, the materials used for the 3D printing were compared with transparent materials used to restore ceramics to evaluate their usability and stability. A total of five specimens were produced, including from photocurable resin made by a stereo lithography apparatus (SLA), epoxy resin, acrylic resin, and more. They were exposed to UV for 96 hours to test for yellowing. Of the two specimens made of photocurable resins and exposed to UV, one was sprayed with a UV blocking agent but the other was exposed as-is. The UV exposure test showed that the specimen made by the SLA and sprayed with a UV blocking agent and the specimen made of epoxy resin were stable in terms of yellowing with a change in the b-value was less than 1. They are thus considered to be suitable materials for the restoration of glass cultural properties. Such glass cultural properties are often diverse in shape and their restoration can be difficult as they generally consist of a range of complex parts that hamper restoration. In this regard, diverse materials should be considered when selecting materials for the restoration of glass cultural properties.

• Journal of the Daesoon Academy of Sciences
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• v.39
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• pp.69-97
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• 2021

'Déconstruction' is a system of thought that induces the emergent property that characterizes contemporary philosophy. The tradition of ancient Greek philosophy evolved over and over again, giving rise to the Renaissance and Enlightenment. It seemed to have reached its end under the historical perspective of modernity. However, contemporary philosophy wanted to see more possibilities through the deconstruction of modern philosophy. If modern philosophy dreams of a strange cohabitation between God and man with the humanistic completion of Plato's philosophy, modern philosophy rejects even that through deconstruction. Although Plato's classical metaphysics is a stable system centered around the absolute, it is ultimately based on God and religion. Under that system, human autonomy is only the autonomy bestowed by God. Contemporary philosophy is one of the results of efforts that try to begin philosophy from the original human voice through deconstruction. Instead of epistemology dependent on metaphysics, they wanted to establish epistemology from human existence and realize the best good that would set humans free through deconstruction. As such, it is no mistake to say that deconstruction is also an extension of the modern topic of human freedom. Deconstruction and human freedom act as one body in that the two cannot be separated from each other. Oddly enough, Daesoon Thought, which seems to have religious faith and traditional conservatism as main characteristics, has an emergent property that encompasses modern and contemporary times. The period of Korea, when Kang Jeungsan was active and founded Daesoon Thought, has an important meaning for those who have a keen view of history. Such individuals likely think that they have found a valuable treasure. This is because that period was a time when ideological activities were conducted due to an intense desire to discover the meaning of human freedom and envision a new world without copying the ways of the West. Instead they looked to face internal problems and raise people's awareness through subjectivity. In other words, the subtle ideas created by Korea's self-sustaining liberalism often take the form of what is commonly called new religions in modern times. Among these new religions, Daesoon Thought, as a Chamdonghak (true Eastern Learning), aims to spread a particular modern value beyond modern times through the concept of Haewon (the resolution of grievances) that was proclaimed by Jeungsan. The Haewon espoused in Daesoon Thought is in line with the disbandment of modern philosophy in that it contains modernity beyond modern times. First, Haewon means to resolve the fundamental resentment of human existence, which arose from Danju's grievance. Secondly, Haewon in Daesoon Thought encompasses the Haewon of the Three Realms of Heaven, Earth, and Humanity centers on a Haewon-esque style of existence called Injon (Human Nobility). Haewon in Daesoon Thought can be understood in the same context as Derrida's philosophy of Deconstruction. Modern deconstruction attempts to expose the invisible structures and bonds within human society and attempt to destroy them. In a similar way, Haewon endeavors to resolve the conflicts among the Three Realms by releasing the bonds of fundamental oppression that hinder the Three Realms of Heaven, Earth, and Humanity.