• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.21-34
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• 2005

To control the obstacles surrounding aerodrome is significant for preventing air accident and ensuring the long sustaining of aerodromes. On the other hand, within a scope of ensuring safe flight operations, the application of Shielding is one of the issues to be importantly considered to manage efficiently the obstacles limitation around aerodromes, to dissolute the private asset privilege limitation from regulation on aerodrome circumference, and to decrease the pains to manage the obstacles, in terms of not only operating safely but also utilizing efficiently the airspace around aerodromes. The ICAO and other aviation-advanced states mitigate the construction limitation or exempt the obligation of obstacle sign by applying the shielding theory that the obstacles are not regarded as obstacles where are below the shadow surface. The Republic of Korea inserted the new regulation including the applying shielding similar to ICAO on Aviation Act and regulations. It is, however, hard to manage the aviation obstacles around aerodrome efficiently with these new regulation. Particularly, there exists much rooms to dispute because it cannot suggest the specific standard which is necessary to apply shielding theory at airspace of aerodromes. Therefore, in this study, the international standards on aviation obstacles were reviewed, analyzed and compared with those of domestic status. The direction of which guideline for control of aeronautical obstacles applicable within domestic circumstances as well as correspondent with international standard was suggested. Particularly, as far as the disputable application of shielding theory is concerned, the alternatives for aviation safety and efficient airspace operation by suggesting the clear standards alternatives were suggested.

• The Journal of Korean Society for School & Community Health Education
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• v.14 no.3
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• pp.27-40
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• 2013

Objectives: This study was conducted at a request for cooperation through an analysis of the effect of toothbrushing facilities at a public health center in Seongdong-gu. Also, with the aim of furnishing basic data to the proposal of a program for improving the ability of school aged children in managing oral cavities and developing a correct toothbrushing habit, the study conducted an investigation of how toothbrushing facilities affect change in the oral environment management ability and behavior of oral health care. Methods: From among elementary schools located in Seongdong-gu, Seoul the study selected A Elementary School where toothbrushing facilities were established and have been operated since 2008, B Elementary School in an adjacent region within the jurisdiction of Seongdong-gu where the demographic environment was similar among schools where toothbrushing facilities were newly established in 2012, and C Elementary School without toothbrushing facilities. Then the study was aimed at first grade students of the schools and an investigation was carried out from April to December 2012. Through a dental checkup, the study evaluated the teeth and periodontal health conditions, and a test of the oral environment management ability was undertaken three times. Regarding change of oral health care behavior, the study carried out a self-recording survey. Results: 1. Concerning decayed and filled tooth(dft) and decayed and filled surface (dfs), A Elementary School where toothbrushing facilities have been established and operated from the past showed a relatively lower decayed, missing, and filled teeth index than B Elementary School where toothbrushing facilities were established in 2012 or C Elementary School without toothbrushing facilities; however, there was no significant difference (p>0.05). For CPI, there was no significant difference by school; however, in looking into the difference between boy students and girl students, Code (0) was discovered higher in boy students whereas Code (1) was shown higher in girl students. 2. In the PHP index test in accordance with the existence of toothbrushing facilities before the installation of toothbrushing facilities, for A Elementary School where toothbrushing facilities have been established and operated from the past, the school recorded 4.28 points whereas B Elementary School where the facilities were established in 2012 recorded 3.51 points. Meanwhile C Elementary School without the facilities posted 4.30 points. Therefore there was a statistically significant difference according to the existence of toothbrushing facilities (p<0.05). 3. In a comparison of teeth health care behavior according to the existence of toothbrushing facilities, the number of answers that the respondent did not brush their teeth after lunch over the past one week was higher in B Elementary School and C Elementary School where there were no toothbrushing facilities. Regarding the average number of brushing after lunch for one week, it was discovered higher in A Elementary School (p<0.01). 4. In change of teeth health care behavior before and after the establishment of toothbrushing facilities, the case of answering that the respondents did not brush their teeth after lunch for one week increased more after establishment than before establishment. Also the average number of teeth brushings after lunch for one week decreased further after the establishment of toothbrushing facilities; however, it did not show a significant difference (p>0.05). One of the reasons that they do not brush their teeth, "the lack of a place", decreased significantly after establishment than before establishment (p<0.05), whereas the answer, "because their friends do not brush their tooth" increased greatly after establishment than before establishment; however, there was no significant difference (p>0.05). 5. In the comparison of the degree of knowledge about dental health according to the existence of toothbrushing facilities, the degree of knowledge about dental health was shown significantly higher in A Elementary School with toothbrushing facilities than in B Elementary School and C Elementary School where there were no toothbrushing facilities (p<0.01). Conclusions: Given the above results, it is difficult to attract change in behavior only with an environmental improvement; therefore, it is deemed necessary to develop an educational program that will help children to make a habit of oral health care not only through a school but also through a related policy and financial support of government organizations as well as the construction of the basis of a systematic and consistent cooperative system with relevant organizations.

• Korean Journal of Microbiology
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• v.45 no.3
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• pp.246-250
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• 2009

Retroviruses enter host cells by membrane fusion between the viral Env proteins on the virus membrane and a virus receptor on the cellular membrane. The envelope protein of the ecotropic Moloney murine leukemia virus is synthesized as a gp85 precursor and is proteolytically cleaved into an extracellular surface unit (SU) and the transmembrane protein (TM). The cytoplasmic tail (16 amino acid; R peptide) of the TM protein is further cleaved by the viral protease during virion maturation. Unlike the wild type Env protrin bearing the R peptide, R peptide-truncated Envelope induces syncytia in susceptible cells. To understand the mechanism of R peptidetruncated Env in syncytium formation, R peptide-truncated Env expressing full-length molecular clone containing EGFP in PRR (proline rich region) of Env was constructed. This molecular clone induced syncytia in transfected NIH3T3 cells, fluorescence was detected in the cytoplasm and at the plasma membrane, while the nuclei did not stain and appeared black by fluorescence microscopy. Interestingly, virions with truncated envelope produced from transfected NIH3T3 cells induced syncytia in NIH3T3 cells, but fluorescence was not detected in the same infected cells. It is believed that cell-free viruses direct the fusion of neighboring cells without infection. Our data suggests that use of EGFP-tagged envelope for monitoring syncytium is a sensitive and convenient method. We also found that virion incorporated the R peptide-truncated Env is able to induce the formation of syncytia by fusion from without.

• Economic and Environmental Geology
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• v.35 no.1
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• pp.25-41
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• 2002

In order to investigate the hydrogeochemical characteristics and contamination of dissolved major ions and heavy metals in the Tancheon River, river water and sediment samples were collected at 18 locations, along a distance of 69 km, between Yongin-si in Kyunggi-do and Samsung-dong in Seoul on October in 2000 and April in 2001. After appropriate sample preparation, waters were analyzed for the dissolved constituents and sediments. The pH values of river waters were in the range of 7.0 to 9.3 and could be plotted in the area of surface environment. The level of $Ca^{2+}$, , CI-, sol-, N0$_{3}$ and HC0$_{3}$ in the Tancheon River were higher than those in world average river water. Most of dissolved constituents in the river waters increased toward downstream from upstream. In particular, high concentrations of Zn2+, Na$_{+}$, CI$^{-}$, SO$_{4}^{2-}$ and N03- were found near densely residential areas and the Sungnam waste water treatment plant. The relative ion enrichment was caused by the inflow of local domestic and industrial sewages. Also, Ca2+ and HC03- concentrations were enriched in the middle of the Tancheon River due to the dissolution of cements. This indicates that the apartment complexes were built on a large scale in the upriver since these ten years and large amounts of construction materials such as cements were flowed into the Tancheon River. Concentrations of heavy metals (Mn, Cd, Cu, Pb, Zn) in sediments from the Tancheon River exceeded the lower limit of tolerence level in bottom sediment established by the Ontario Ministry of the Environment (OME) of Canada. In particular, these metals were highly elevated in sediment (TSM-12) collected from near the Sungnam waste water treatment plant. Heavy metals were higher enriched in sediments collected from dry period rather than wet period.

• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.158-164
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• 2009

Biosorption uses adsorbents derived from non-living biomass and removes toxic metals from industrial wastewater. The objective of this research was to evaluate the potential of low cost biosorbents to remove heavy metal ions (Cd, Cu, Pb and Zn) from aqueous solutions using chemically modified rice husk and saw dust (Pseudotsuga menziesi, Quercus, Populus). Batch-type adsorption experiments were carried out using rice husk and saw dust treated with NaOH and/or tartaric acid in artificial wastewater 100 mg metal/L). The experimental results showed that the adsorption specificity of each biosorbent was Pb > Cu > Cd > Zn irrespective of the types of biosorbents. The adsorption capacity of Pb and Cu onto NaOH-treated sawdust was increased 2${\sim}$3 times compared to the untreated one. In addition, the tartaric acid treatment increased the adsorption capacity of rice husk for Zn and Cd approximately 5${\sim}$10 fold compared to the untreated one. Surface conditions and changes in functional groups by chemical modification of each biosorbent were confirmed by SEM and FT-IR. Overall, the results show that chemical modification increases the metal removal capacity of rice bran and sawdust.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.101-109
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• 2012

Traditional village forests in Jeju Island represent unique cultural landscape with a history of more than several hundred years as a national cultural asset in Korea. In this paper, the characteristics and meaning of traditional village forests in Jeju Island was compared with the Dangsan and Bibo forests at inland. There are 368 Oreums, parasitic volcano, and 391 shrines of Dang(Divine place) in Jeju. Life, culture and tradition of rural villages are all connected with the Dang and Oreum in Jeju. It has been found from this study that the village in Jeju were established as a cultural landscape on the surface of natural landscape. The features of traditional villages focused on the Dang and Oreum in Jeju Island were similar to the Dangsan and Bibo forestsat inland villages. The Oreum represents mountain and the Pojedan forest is newly found in Sangmyung-ri. The seashore areas are covered by vaocanic rocks in Jeju and large scale windbreaks are hardly found. The stone tower at Sinheung-ri built for blocking sand movement represents Bibo forest. The special attribute of the Dang in Jeju is that it is close to real life and believers are still remain. In 2009, the Jeju Chilmeoridang Yeongdeunggut ritual was nominated as an Intangible Cultural Heritage of Humanity by UNESCO. The shrine of Dang, however, has been degraded fast by construction of seashore road and Jeju Olle trail path. As for the world cultural heritage discussed at international conferences, it is important that there is sustainability on the right to enjoy cultural heritage. Integrated efforts from local residents, local governments and national government are needed to set up a management scheme for the Dang culture. Rural villages in Jeju with the Dang and Oreum are expected to get an international attention as to have traditional cultural landscapes of Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.5
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• pp.113-121
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• 2010

Shumi-sen(須彌山), built by Nohjagong(路子工) in the southern garden of the Palace Garden during the Asuka Period, is understood as being Sumeru based on an Indian perspective of the theory of the origin of universe. It is also viewed as Mt. Myogoh from a Chinese Buddhist worldview. It is thought to be a type of assembled stone structure with Poong-ryoon (風輪)-Su-ryoon(水輪)-Geum-ryoon(金輪)-Ji-ryoon(地輪) carved into each of the 4 stone pieces. These building shapes are thought to have been utilized as stone for exterior construction as opposed to those structures built during the Shilla Period of China and Korea. Aside from Nohjagong's record of Shumi-sen, most of the records from Japan's period of the time suggest that Shumi-sen was an important element that played a role in the scenery of the seasonal outdoor gardens. It is also thought, from the sentences and expressions surrounding the records, that a combination of the seasonal sceneries was utilized centered on Shumi-sen, and that they were all used during festival events. From a perspective of analysis and interpretation dependent on the limited literature and on observation, it cannot be verified whether the Mt. Sumeru Stone(須彌山石) excavated from the Stone God Ruins is the same Shumi-sen that Nohjagong built along with Okyo(吳橋), but it is thought that the 'Shumi-sen type stone structure' that was later built repeatedly as part of the palace garden facilities is identical to the Shumi-sen built at the Imperial Palace's southern garden, or at least a re-built structure based on the Shumi-sen that Nohjagong built with stones and ponds used to create the foundation. Thus, Shumi-sen that Nohjagong supposedly built along with Okyo is suspected to be a figurative rock arrangement and, at the same time, a miniaturized scenic rock arrangement(縮景樹石) that maximized the shape of Buddhism's Shumi-sen. On the other hand, the surface pattern on Mt. Sumeru Stone is very similar to the multi -layers of mountainous pattern icons expressed in the patterns of the Great Golden Incense Burner(百濟金銅大香爐) or Mountain-Water Scenery Sculptural Brick(山水山景紋?) that were built during the Baekjae pcriod aod the rear side of Hwalsuk-jebul Basal Byungipsang(滑石諸佛菩薩竝立像); it is suspected that similar patterns would have been used if patterns were made on Shumi-sen that Nohjagong built. Also in consideration of the physical theory of MI. Sumeru Stone, the Siphon theory of using a pressure difference in water level was applied to the fountain facilities of Mt. Sumeru Stone that seemed to have been built from the practical rock arrangement perspective for the purpose of feasts, etc.

• Journal of Wetlands Research
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• v.12 no.1
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• pp.1-14
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• 2010

Changes in wetland soil properties of two constructed wetlands after their constructions were compared to those of a natural wetland to determine if they could be used for the evaluation of the success of constructed wetlands and the assessment of their functions. One natural wetland as a reference wetland and two constructed wetlands(treatment wetland and experimental wetland) with different contaminant inflow characteristics were selected for this study. Major physicochemical properties of wetland soil such as soil texture, water content, pH, CEC(cation exchange capacity), organic matter content, total nitrogen, and available phosphorus were monitored to investigate the effects of inundation and accumulation of organic matters and nutrients on the wetland soil development. There was a clear difference in soil texture between the natural wetland and the constructed ones, with the high sand content in the constructed wetlands as compared to the high clay content in the natural one. Gradual increases of silt and clay contents over time were observed in the constructed wetlands. The soil of the natural wetland was higher in water content and organic matter but lower in pH than those of the constructed wetlands. The pH of the constructed wetlands reached near neutral ranges after initial increase. CEC and nutrient concentrations of the constructed wetlands seemed to be affected mainly by outside inflows of organic matter and contaminants. Concentrations of organic matter and nutrients decreased over time in the experimental wetland where surface and deep soils with different characteristics were mixed during its construction, suggesting that changes in soil properties during wetland constructions may affect the development of wetland soils or wetland biogeochemistry. This study showed that changes in physicochemical properties of soils in constructed wetlands could be used to assess the success of constructed wetlands and their functions, and also the importance of reference wetlands for the appropriate assessment.

• Journal of Wetlands Research
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• v.15 no.1
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• pp.25-34
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• 2013

The purpose of this study is to investigate the properties of Menyanthes trifoliata habitat in coastal lagoons. To characterize plant composition in the habitats in the lagoon, the plot sampling method was applied. The depths of water and floating mat were measured. Surface water quality factors including pH, electrical conductivity (EC), dissolved oxygen (DO), and total dissolved solids (TDS) were measured in the sites. Phosphate, nitrate, ammonium, and major cations were measured in laboratory. The wetland has 78 taxa of wetland plants. The average coverage and density of M. trifoliata was 62.6% and $71.2/m^2$, respectively and Phragmites australis is important associate in Sunyoodam lagoon. The average depths of floating mats were 26.5cm in M. trifoliata and 68.9cm in the P. australis-M. trifoliata communities, and the water depth below the mat was 106.5cm and 17.7cm, respectively. The values of pH, DO, EC and TDS in the water were 5.06, 46.1%, 59.4 ${\mu}s/cm$, and 29.3 mg/L, respectively. The concentrations of phosphate, nitrate, and ammonium showed 47.2, 9321, and 15.9 ${\mu}g/L$, respectively. The concentrations of Ca, K, Na, and Mg had 11.1, 1.5, 15.1, and 11.3 mg/L, respectively. The habitats of M. trifoliata in the lagoon corresponds to a kind of lowland communities in Hewett's classification. To conserve the habitats of M. trifoliata in Sunyoodam lagoon, the supply of open water area, the construction of observation deck, and the block of inflow from the surrounding paddy fields are needed in the future.

• Korean Journal of Heritage: History & Science
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• v.38
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• pp.329-358
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• 2005

The Three storied Stone pagoda in Gameunsa Temple site, one of the early staged stone pagodas, has been known as a standard for Silla stone pagodas. A stone pagoda is not only a stone art work and but also a stone structure. Most studies and investigation of the stone pagoda has done mainly based on style and chronological research according to an art historical view. However, there is not an attempt to research the stone pagoda as a stone architecture. Most Korean experts at the stone pagoda has art history in their background. Engineers who can understand the structure of the stone pagoda are very limited. More architectural and engineering approach is need to research not only art historial understanding but also safety as a structure. We can find many technical know-how from our ancestors who made stone pagodas. 1. To reduce any deformation such as relaxation and sinking of BuJae which is caused by a heavy load, the BuJae (consist of a foundation stone and lower stereobates) should be enlarged. 2. A special construction method for connection between Myonsuk and Tangjoo was invented. This unique method is not used any longer after the Three storied Stone pagoda in Gameunsa Temple site. 3. The upper BuJae and the lower BuJae are missed each other by making a difference of Okgaesuk and Okgaebatchim in size. It is done for a distribution of perpendicular load and a prevention for relaxation of BuJae. 4. The center of gravity in the BuJae is located to the center of the stone pagoda by trimming the upper surface of the Okgaebatchim into a convex shape. The man who made stone pagodas had excellent knowledge on the engineering and techniques to understand the structure of the stone pagodas. We can confirm it as follows: the enlarged BuJae, dislocated connection between upper Bujae and lower BuJae, and moving the center of gravity close to the center of the stone pagoda.