• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.1-7
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• 2004

Roads, like bikeways, parkways and walks, are to be just capable of supporting light traffic and traveling public, but they are required to be human friendly and environmental-oriented. Lately soil-solidifier mixture, a kind of soil-cement, has developed and has been applied to the recycling and environment-oriented pavement as the surfacing material. Soil-solidifier pavement structure has been designed by only experience. To design this pavement mechanically, it is necessary to find out basic engineering properties of soil-solidifier mixture. This study focuses on finding out mechanical characteristics of the mixture according to mixture proportions and aging. Test molds with various mixture proportions are made, and then unconfined strength tests are performed for test molds with aging of the mixture. As the result of this study, it is found that the strength of the mixture increases with amount of cement and that maximum strength is achieved at 6%$\sim$8% of the ratio of solidifier and water. The strength increase rapidly until 14 days, after then slowly. After 28 days the strength of the mixture approaches to the constant value. The heat of hydration during curing of the mixture is measured no significantly. It also shows that temperature characteristics of the mixture is similar to that of soil. Since this mixture is mixed with soil and is able to improve engineering problems in pavement due to temperature, this mixture is expected to use effectively in the environment-oriented pavement for light traffic.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.261-277
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• 2017

This study defines influencing sections as the part of the road section where passing vehicles are traveling with the lower speed compared to speed limit due to speed humps. The influencing section was divided into 3 parts; influencing section before the speed hump, interval section, and influencing section after the speed hump. This analysis focused on the changes of each part depending on installation types, vehicle types, and daytime or nighttime. For the interval section, especially, the ratio of distance traveled with lower speed than speed limit to interval section is defined as effective influencing section ratio to be analyzed. Vehicle speed profiles were collected with a speed gun to extract influencing section lengths. The survival analysis was applied and estimated survival functions are compared with each other by several statistical tests. As a consequence, the average length of influencing section on the 50m sequential speed humps was 75.3% longer during the deceleration than that of isolated speed hump, and 18.9% during the acceleration. The effective influencing section ratio for the 30m and 50m sequential speed humps had a small difference of 81.0% and 76.0% while the absolute values of the section that passing speed were less than the speed limit were longer on 50m sequential speed humps, each being 24.3m and 38.0m. Using the log rank test, it was evident that sequential speed humps were more effective to increase the length of influencing sections compared to the isolated speed hump. Vehicle type was the strong factor for influencing section length on the isolated speed hump, but daytime or nighttime was not the effective one. This research result can be used for improving the efficiency selecting the installation point of speed humps for road safety and estimating the standard of the distance between sequential speed humps.

• Journal of the Economic Geographical Society of Korea
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• v.21 no.1
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• pp.20-33
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• 2018

Population distribution in urban space varies with transportation flow changing along time of day. Transportation flow is directly affected by the activities of urbanites and the distribution of related facilities, since the flow is the result of moving to the point where the facilities associated with their activities are located. It is thus necessary to analyze the spatio-temporal characteristics of the urban population distribution by integrating the distribution of activity spaces related to the daily life of urbanites and the flow of transportation. The purpose of this study is to analyze the population distribution in urban space with daily and weekly time bases using the building database and T-card database in the city of Seoul, which is rich in information on land use and transportation flow. For a time-based analysis that is difficult to grasp by general statistical techniques, a four-dimensional visualization method combining time and space using a Java program is devised. Dynamic visualization in the four-dimensional space and time allows intuitive analysis and makes it possible to understand more effectively the spatio-temporal characteristics of population distribution. For this purpose, buildings are classified into three activity groups: residential, working, and commercial according to their purpose, and the number of passengers traveling to and from each stop site of bus and subway networks in the T-card database for one week is calculated in one-minute increments, Visualizing these and integrating transportation and land use, we analyze spatio-temporal characteristics of the population distribution in Seoul. As a result, it is found that the population distribution of Seoul displays distinct spatio-temporal characteristics according to land use. In particular, there is a clear difference in the population distribution pattern along the time axis according to the mixed aspects of working, commercial, and residential activities. The results of this study can be very useful for transportation and location planning of city facilities.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.455-469
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• 2008

Statement of problems: In the area of dental care, the institutionalized elderly have placed the most vulnerable state, and we cannot find their subjective need of dental treatment because of the physical and mental disabilities, But we have no basic investigation of their oral health conditions. Purpose: The aims of the current study were to investigate the oral health status of institutionalized elderly patients who are in the least benefited side of dental service, and to analyze their dental treatment needs. Material and methods: The survey of the oral status was carried out on 758 institutionalized elderly, and 212 elderly who was more than 65 years old from D dental office, and it was based on the Guidelines of Oral Health Research of year 2000 in Republic of Korea. Results and conclusion: The DMFT index of the institutionalized elderly appeared higher than that of the same ages in control group, and it increased with age. The number of residual teeth of the institutionalized elderly appeared lower than that of the same ages in control group, and it decreased with age (P < .05). The number of fixed partial denture in institutionalized elderly was lower than that of the same ages in control group (P < .05). The percentage wearing removable partial denture was not significant between the elderly in institutions and the control group, and was not different according to age between the two groups. The percentage of institutionalized elderly wearing complete denture appeared lower than that of the same ages in control group, and it increased with age. The percentage of institutionalized elderly needing complete denture was higher than that of control group, and the percentage of elderly needing complete denture on the maxilla was higher than that of the mandible. 16.35% of the institutionalized elderly was living without denture in spite of their fully edentulous state. The need for complete denture increased rapidly with age. The number of valued teeth and dental prostheses in shortened dental arch concept and number of occluding pairs of teeth of institutionalized elderly were lower than that of the control group (P < .05). In institutionalized elderly, the number of residual teeth, the number of fixed partial dentures, and the percentage wearing removable partial dentures were higher in the mandible, and the percentage wearing complete dentures was higher in the maxilla (P < .05). The rate of institutionalized elderly needing prosthodontic treatment appeared to be 67.82%, where the number of occluding pairs of teeth was less than 10. When it is difficult to evaluate the subjective need of dental treatment as with the institutionalized elderly, estimation using the number of occluding pairs of teeth can be a useful indicator that can project treatment needs. For the oral health care of institutionalized elderly, it is essential to increase the awareness of nurses and caregivers who take care of them, about the importance of the oral health. Since the average life span and number of residual teeth are increasing gradually, the welfare policy should be changed to implementing regular dental examinations, preservative treatment forms and oral health control of dentulous patients where the traveling-treatment system and visit system are supplemented. And principles should be set that the present denture project of edentulous patients should be done by specialists who'll also be responsible for postmanagement. Through this research of institutionalized elderly, the oral health status which is worsened by aging could be confirmed. And the interest and positive participation of dental society on the elderly should come first in order to solve the rising treatment needs of the elderly patients.

• The Korean Journal of Air & Space Law and Policy
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• v.29 no.2
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• pp.205-237
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• 2014

Last 50 years there were a lot of space subjects launched by space activities of many states and these activities also had created tremendous, significant space debris contaminating the environment of outer space. The large number of space debris which are surrounding the earth have the serious possibilities of destroying a satellite or causing huge threat to the space vehicles. For example, Chinese anti-satellite missile test was conducted by China on January 11, 2007. As a consequence a Chinese weather satellite was destroyed by a kinetic kill vehicle traveling with a speed of 8 km/s in the opposite direction. Anti-satellite missile tests like this,contribute to the formation of enormous orbital space debris which can remain in orbit for many years and could interfere with future space activity (Kessler Syndrome). The test is the largest recorded creation of space debris in history with at least 2,317 pieces of trackable size (golf ball size and larger) and an estimated 150,000 debris particles and more. Several nations responded negatively to the test and highlighted the serious consequences of engaging in the militarization of space. The timing and occasion aroused the suspicion of its demonstration of anti-satellite (ASAT) capabilities following the Chinese test of an ASAT system in 2007 destroying a satellite but creating significant space debris. Therefore this breakup seemed to serve as a momentum of the UN Space Debris Mitigation Guidelines and the background of the EU initiatives for the International Code of Conduct for Outer Space Activities. The UN Space Debris Mitigation Guidelines thus adopted contain many technical elements that all the States involved in the outer space activities are expected to observe to produce least space debris from the moment of design of their launchers and satellites until the end of satellite life. Although the norms are on the voluntary basis which is normal in the current international space law environment where any attempt to formulate binding international rules has to face opposition and sometimes unnecessary screening from many corners of numerous countries. Nevertheless, because of common concerns of space-faring countries, the Guidelines could be adopted smoothly and are believed faithfully followed by most countries. It is a rare success story of international cooperation in the area of outer space. The EU has proposed an International Code of Conduct for Outer Space Activities as a transparency and confidence-building measure. It is designed to enhance the safety, security and sustainability of activities in outer space. The purpose of the Code to reduce the space debris, to allow exchange of the information on the space activities, and to protect the space objects through safety and security. Of the space issues, the space debris reduction and the space traffic management require some urgent attention. But the current legal instruments of the outer space do not have any binding rules to be applied thereto despite the incresing activities on the outer space. We need to start somewhere sometime soon before it's too late with the chaotic situation. In this article, with a view point of this problem, focused on the the Chinese test of an ASAT system in 2007 destroying a satellite but creating significant space debris and tried to analyse the issues of space debris reduction.

• Korean Journal of Heritage: History & Science
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• v.53 no.1
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• pp.184-203
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• 2020

The Confucian ruling class of the Joseon Dynasty regarded Buddhist rituals as "dangerous festivals." However, these Buddhist ceremonies facilitated transitions between phases of life from birth till death and strengthened communal unity through their joint practice of the rites. Ritual spaces were decorated with various utensils and objects that transformed them into wondrous arenas. Of these ornaments, Buddhist paintings served as the most effective visual medium for educating the common people. As an example, a painting of the Ten Kings of the Underworld (siwangdo) could be hung as a means to illustrate the Buddhist view of the afterlife, embedded in images not only inside a Buddhist temple hall, but in any space where a Buddhist ritual was being held. Demand for Buddhist paintings rose considerably with their use in ritual spaces. Nectar ritual paintings (gamnodo), including scenes of appeasement rites for the souls of the deceased, emphasized depictions of royal family members and their royal relatives. In Chinese paintings of the water and land ceremony (suryukjae), these figures referred to one of several sacred groups who invited deities to a ritual. However, in Korean paintings of a nectar ritual, the iconography symbolized the patronage of the royal court and underlined the historicity and tradition of nationally conducted water and land ceremonies. This royal patronage implied the social and governmental sanction of Buddhist rituals. By including depictions of royal family members and their royal relatives, Joseon Buddhist paintings highlighted this approval. The Joseon ruling class outwardly feared that Buddhist rituals might undermine observance of Confucian proprieties and lead to a corruption of public morals, since monks and laymen, men and women, and people of all ranks mingled within the ritual spaces. The concern of the ruling class was also closely related to the nature of festivals, which involved deviation from the routines of daily life and violation of taboos. Since visual media such as paintings were considered to hold a special power, some members of the ruling class attempted to exploit this power, while others were apprehensive of the risks they entailed. According to Joseon wangjo sillok (The Annals of the Joseon Dynasty), the Joseon royal court burned Buddhist paintings and ordered the arrest of those who created them, while emphasizing their dangers. It further announced that so many citizens were gathering in Buddhist ritual spaces that the capital city was being left vacant. However, this record also paradoxically suggests that Buddhist rituals were widely considered festivals that people should participate in. Buddhist rituals could not be easily suppressed since they performed important religious functions reflecting the phases of the human life cycle, and had no available Confucian replacements. Their festive nature, unifying communities, expanded significantly at the time. The nectar ritual paintings of the late Joseon period realistically delineated nectar rituals and depicted the troops of traveling actors and performers that began to emerge during the seventeenth century. Such Buddhist rituals for consoling souls who encountered an unfortunate death were held annually and evolved into festivals during which the Joseon people relieved their everyday fatigue and refreshed themselves. The process of adopting Buddhist rituals-regarded as "dangerous festivals" due to political suppression of Buddhism in the Confucian nation-as seasonal customs and communal feasts is well reflected in the changes made in Buddhist paintings.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.10-20
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• 2020

This study aims to analyze the developed characteristics of the knowledge and information of gardens through garden or flowering plant books compiled in the 15th and 19th centuries of Joseon Dynasty. Diachronically analysis of the garden or flowering plant books classified the characteristics in which knowledge and information about gardens are developed by the period, and looked at the factors. The results are as follows; First, the relationship between the authors who compiled the garden or flowering plant books had similar characteristics to the genealogy of Realist School of Confucianism(實學) in the Joseon Dynasty. Kang, Hee-An's practical features influenced later realist school of confucianism scholars. Lee, Su-Gwang has accumulated knowledge of the garden through his experience of traveling the diplomatic envoy to China. Since then, Hong Man-sun's ideology has been related to Charles, a member of the Southerners. Seo Yu-gu was also able to accept Realist School of Confucianism in an integrated way through the Jungnong school's theory and interaction with the Jungsang school. Ryu, Jung-Lim's relationship with the Jungnong school emerged as he added to the 『Jeungbosanrimgyeongje(增補山林經濟)』. Second, the 『Yanghwasorok(養花小錄)』, 『Jibongyuseol(芝峯類說)』 「Hwuimok(卉木)」, 『Hangjeongrok(閑情錄)』, 『Sanrimgyeongje(山林經濟)』 「Yanghwa(養花)」, 『Jeungbosanrimgyeongje(增補山林經濟)』 「Yanghwa(養花)」, 『Hwaamsurok(花庵隨錄)』 and 『Imwongyeongjeji(林園經濟志)』 「Yewonji(藝畹志)」 contain garden plant characteristics, cultivation methods, and management methods. The 『Imwongyeongjeji(林園經濟志)』 「Seomyongji(贍用志)」, 「Iunji(怡雲志)」, 「Sangtaekji(相宅志)」 contain details on the location selection of gardens, the layout of facilities, how to create them and materials. The description of these garden or flowering plant books was found to be the most common introduction with 55 percent, followed by methodologies(42.8%), the Lichi Theory(理氣論, 15.5%), the classification(12.4%), and the convention(1.9%). Third, based on the importance of knowledge and information on gardens, the garden or flowering plant books related to the period were classified as early period, including 『Yanghwasorok(養花小錄)』, 『Jibongyuseol(芝峯類說)』 which were compiled before the 17th century. The 18th-century compiled 『Sanrimgyeongje(山林經濟)』 and 『Jeungbosanrimgyeongje(增補山林經濟)』 were classified as middle period, and the 19th-century compilation of 『Imwongyeongjeji(林園經濟志)』 was classified as late period. The garden or flowering plant books were cited the contents of ancient Chinese books, the author's experiences and opinions contained in the preceding period in later garden books. And the reinforcement of garden knowledge was made to reflect the agricultural technology and expertise developed at the time of writing. Fourth, based on analysis of the development and acceptance of knowledge information in garden by period, In the early period was dealing with floriculture as a way to explore the logic of things. Later, in the 18th century, a vast influx of garden knowledge information came from China. Among scholars, they secured justification for garden creation as part of various knowledge-seeking activities, which expanded their expertise in gardens. In response to the trend of gardening in the 19th century, professional books were written based on knowledge and information on gardens that were collected in the past, and systems were established such as the collection and management of garden plants, construction methods, enjoying methods, and self-realization.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.3
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• pp.369-378
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• 2003

Statement of Problem: Recently, resin cements have become more widely used and have been accepted as prominent luting cements. Current resin cements exhibit less microleakage than conventional luting cements. However, the constant contact with water and exposure to occlusal forces increase microleakage even in resin cements inevitably. Most bonding resins have been modified to contain a hydrophilic resin such as 2-hydroxyethylmethacrylate (HEMA) to overcome some of the problems associated with the hydrophobic nature of bonding resins. By virtue of these modifications, bonding resins absorb a significant amount of water, and there may also be significant stresses at bonding interfaces, which may adversely affect the longevity of restorations. Therefore the reinforcement of water stability of resin cement is indispensable in future study. Purpose: This study was conducted to examine the influence of water retention on microleakage of two resin cements over the period of 6 months. Materials and Methods: 32 extracted human teeth were used to test the microleakage of a single full veneer crown. Two resin cements with different components and adhesive properties - Panavia F (Kuraray Co., Osaka, Japan) and Super-Bond C&B (Sun Medical Co., Kyoto, Japan)- were investigated. The storage medium was the physiological saline solution changed every week for 1 month, 3 months, and 6 months. One group was tested after storage for 1 day. At the end of the each storage period, all specimens were exposed to thermocycling from $5^{\circ}C$ to $55^{\circ}C$ of 500 cycles and chewing simulation of 50,000 cycles, and then stained with 50% silver nitrate solution. The linear penetration of microleakage was measured using a stereoscopic microscope at ${\times}40$ magnification and a digital traveling micrometer with an accuracy of ${\pm}3{\mu}m$. Values were analyzed using two-way ANOVA test, Duncan's multiple range tests (DMRT). Results : Statistically significant difference of microleakage was shown in the 3-month group compared with the1-day or 1-month group in both systems (p<0.05) and there were statistically significant differences in microleakage between the 3-month group and the 6-month group in both systems (p<0.05). The two systems showed different tendency in the course of increased microleakage during 3 months. In Panavia F, microleakage increased slowly throughout the periods. In Super-Bond C&B, there was no significant increase of microleakage for 1 month, but there was statistically significant increase of microleakage for the next 2 months. For the mean microleakage for each period, in the 3-month group, microleakage of Super-Bond C&B was significantly greater than that of Panavia F. On the other hand, in the 6-month group, microleakage of Panavia F was significantly greater than that of Super-Bond C&B (p<0.05). Conclusion: Within the limitation of this study, water retention of two different bonding systems influence microleakage of resin cements. Further studies with the longer observation periods in viro are required in order to investigate water stability and the bonding durability of the resin cement. CLINICAL IMPLICATIONS Microleakage at the Cement-tooth interfaces did not necessarily result in the failure of the crowns. But it is considered to be a major factor influening the longerity of restorations. Further clinical approaches for decreasing the amount of microleakage are required.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.1
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• pp.20-33
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• 2018

This study aims to illuminated landscape of Joseon Dynasty in the end of 19th century when Joseon dynasty began to modernize through the perspective of Westerners. Historical meaning to Western people's landscape records has been preceded. And landscape typology and their perception were analyzed. The results were as follows. First, the Westerners who visited Joseon dynasty at that time were involved in the historical and political situation of the Joseon Dynasty or understood their culture through traveling for so long. And record of Westerners is a significant data to analyze scenery at that time because common contents appear in various books. Second, the landscape of Joseon dynasty that appears in Western records was mainly recorded in small towns and villages, natural environments, scenic sites, historic sites, modern facilities, and cultivated areas. Small towns and villages are mainly mentioned with shabby alleys and dense houses. And natural landscape were identified to mountain landscapes and diverse geomorphological landscape that surrounding vegetation along the coast and rivers. The palaces, fortress and temples were recorded as main objects of scenic sites and historic site. And western-style buildings such as foreign legations and settlements, churches and schools were mentioned in the modernized facilities. A cultivated land was confirmed to be underdeveloped and neglected, but as range of view became wider, it was seen to a peaceful and prosperous rural landscape. Third, Westerners' landscape perception of Joseon dynasty at that time can be deduced from positive or negative perceptions. The residential environment was perceived as negative because it was unsanitary and backward. On the contrary, outstanding natural landscapes, scenic sites and historic sites, and upper class gardens were perceived as positive. For modernized landscapes, positive and negative perceptions were similarly mentioned. Positive perceptions were formed in improvement of civilized landscape, and appeared negative perception because damaged traditional landscapes and heterogeneity.

• Cross-Cultural Studies
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• v.45
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• pp.219-243
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• 2016

The life of Antonin Artaud exactly reproduces a very cruel drama. He lived in constant anguish and suffered from severe mental pain. This research will trace his thoughts in his writings while he was a prisoner of language. Artaud was a poet filled with anxiety about language, things, being, and thought. Whenever he tried to explain the mystery of being by means of mundane language, he experienced psychological agony. His poetic thoughts began to break down, because of his identity loss. Nevertheless, he was destined to grasp the world through language. Artaud had suffered from mental illness during his youth. His mental illness was associated with his difficulty in creating poetry. In this research, the letter, Correspondance avec Jacques $Rivi{\grave{e}}re$, is analyzed. The poet refers to "the collapse of the spirit's core, and the erosion of the fundamental thought that slips away" to convey his linguistic incompetence. Hereafter, he constantly demonstrated anxious mental symptoms. Even though he became mentally deranged, he maintained his consciousness, as is apparent in his writings. Also, his spiritual belief is reflected in his mental uneasiness. While he was traveling through the Tarahumaras area in Mexico, he was obsessed with its primitive belief in the Peyote rituals, and he immersed himself in performing them. His unchristian belief was the product of his mystical personality. Until his last breath, he did not give up writing. Artaud's mental derangement does not mean lunacy, but if one insists in calling it so, that is a metaphor. His derangement comes from his refusal to accept his limitations and from his aspiring to regard his body in the same light as his intellectual perceptions. His intellect could manifest more easily when his mind was elevated to the extreme. Artaud's lunacy is no different from that of a profound philosopher. The lives of poets who suffer from mental derangement are more poetic than the lives of those who do not. Artaud's atypical emotions provide a way of to measure our own limitations, helplessness, and resignation. His scream is nonsegmental but different from that of a mental patient. That difference is why people are interested in his works and wish to delve into his writings.