• Restorative Dentistry and Endodontics
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• v.28 no.1
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• pp.89-99
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• 2003

The purpose of this study was to investigate the bonding of resin- based root canal sealer, AH26 when the sealer was applied as a thin layer between dentine and gutta-percha surface. In this study forty non-caries extracted human molars and resin-based root canal sealer(AH 26, DeTrey/Dentsply, Germany) were used. Disks of gutta-percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for thermoplastic obturation were used and dentin surfaces were treated with 2% NaOCl(Group 1) or 2%NaOCl+17% EDTA(Group 3). Disks of gutta-Percha, 6mm in diameter.6mm thick (Diadent/Dentsply, Korea) for conventional obturation were used and dentin surface were treated with 2% NaOCl(Group 2) or 2%NaOCl+17% EDTA(Group 4). Enamel was removed by a horizontal section 1mm below the deepest portion of the central occlusal groove by using a watercooled low speed diamond saw. A second horizontal section was done around cementoenamel junction. Exposed dentin surface was cut to approximately $8{\times}8{\;}mm$ rectangular shape and was ground against 320, 400, 600 grade silicon carbide abrasive paper serially. After grinding, the dentine surface were soaked in a solution of 2% NaOCl for 30 minutes and twenty of specimens were treated with 17% EDTA solution for 1 minute. The treated specimens were washed and dried, Root canal sealer, AH26 was prepared according to the manufacture's instructions The Gutta-percha and dentin surface were coated with a thin layer of the freshly mixed seal or. The specimens were left overnight at room temperature. After their initial set, they were transferred to an incubator at $37$^{\circ}C$ for 72 h. After 72 hours, resin blocks were made. The resin block was serially sectioned vertically into stick of $1{\cdot}1mm$. Twenty sticks were prepared from each group. After that, tensile bond strength f3r each stick was measured with Microtensile Tester Failure patterns of the specimens at the interface between gutta-percha and dentin were observed under the SEM(x1000) and Stereomicroscope (LEICA M42O, Meyer Inst., TX U.S.A) at 1.25 x25 magnification. The results were statistically analysed by using a One-way ANOVA and Tukey's test. The results were as follows; 1. Tensile bond strengths($mean{\pm}SD$) were expressed with ascending order as follows: Group 1, $3.09{\pm}$ 1.05Mpa : Group 2, $6.23{\pm}1.16MPa$ : Group 3, $7.12{\pm}1.07MPa$ : Group 4, $10.32{\pm}2.06MPa$. 2. Tensile bond strengths of the group 2 and 4 used disks of gutta-percha for conventional obturation were significantly higher than that of the group 1 and 3 used fir thermoplastic obturation. (p < 0.05). 3. Tensile bond strengths of the group 3 and 4 treated with 2% NaOC1+17% EDTA were significantly higher than that of the group 1 and 2 treated with 2% NaOCl. (p < 0.05). 4. In analysis of failure patterns at the interface between sealer and gutta-percha, there were observed 49 (61%)cases of adhesive failure patterns and 31 (39%) cases of mixed failures patterns.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.4
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• pp.85-97
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• 2010

This study analyzed the distribution, structure and environmental condition of the vegetation of the Chionanthus retusus Lindly et Paxton community at the Wansanchielbong in the Jeonju city to offer basic data for sustainable conservation and ecological management system. And the results are as follows; 1. The average pH of soil at the community was pH 5.69 and it was slightly higher than the average of forest soil pH of Korea. But if the degree of pH will be down, it will be needed some more fertilization of Calcium. 2. The total average for contents of organism was 4.98%. And the nitrate - nitrogen content(mg/kg) of A, B, C, D quadrat was 20.29%, 28.87%, 7.65%, and 23.3% respectively. And there were good condition except quadrat C which was contaminated by amount of earth and sand. 3. The flora of the Chionanthus retusus Lindly et Paxton community was listed as 60 taxa; 37 families, 50 genera, 47 species, 10 varieties and 3 forms. The average appearance species of each Quadrat were A sector 30, B sector 26, C sector 19 and D 19 taxa respectively. 4. Surveyed woody plants in the community were as follows : Chionanthus retusus, Zelkova serrata, Quercus variabilis, Cornus walteri, Robinia pseudo-acacia and those were mixed status. And Chionanthus retusus, Zelkova serrata, Robinia pseudo-acacia, Albizzia julibrisin, Cudrania tricuspidata, Symplocos chinensis for. pilosa were mixed in mid layer trees. Herbaceous plants were founded such as Chionanthus retusus, Zelkova serrata, Robinia pseudo-acacia, Grewia parviflora, Rosa multiflora, Trachelospermum asiaticum was dominant with 35~64% in the ground cover, and Commelina communis, Calamagrostis arundinacea, Dryopteris bissetiana, Lilium lancifolium were founded also. 5. The importance values of Chionanthus retusus was 40.2% in the quadrat A1, 50.2% at quadrat A, 50.0% B1, 45.2% B2, 22.4% C1, 73.6% C2, 33.2% D1 and the total average of I.V. was 44.9%. 6. The average height of surveyed Chionanthus retusus was 5.7m and the average DBH was 12.4cm. The number of trees higher than 2m were 107 and the number of trees lower than 2m were 63. The total numbers of Chionanthus retusus were 170. 7. The age of surveyed Chionanthus retusus were analyzed 42 thru 87 years old and that of Zelkova serrata were 42, Quercus variabilis were 60, Quercus aliena were 48, Robinia pseudo-acacia were 40. 8. The number of trees with DBH 40 through 50cm were 6, and that of 30~39cm were 3, and that of 20~29cm were 16, so the total number that was over 20cm was 25. And there were 70 trees under 10cm of DBH and 63 seedlings. It will be very important data to conserve the habitat that the structure and environmental condition of the Chionanthus retusus Lindly et Paxton community at the Wansanchielbong was stable, and sustainable monitoring will be needed. Now that community is nurse forest of Jeonju City but more positive preservation plan will be needed and assigning monument of city or province also be necessary.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.1-11
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• 2020

Noksan is a green area in the form of a hill located inside Gyeongbokgung Palace, unrecognized as a cultural heritage space. This study analyzed the literature and the actual site to derive its landscape meaning by examining the background for the formation of Noksan and how it changed. As a result, the identity of Noksan was related to the geomagnetic vein, pine forest, and deers, and the following are its landscape meaning. First, several ancient maps, including the 「Map of Gyeongbokgung Palace」 depicted the mountain range continuing from Baegaksan(Bugaksan) Mountain to areas inside Gyeongbokgung Palace, and Noksan is a forest located on the geomantic vein, which continues to Gangnyeongjeon Hall and Munsojeon Hall. On Bukgwoldo(Map of Gyeongbokgung Palace), Noksan is depicted with Yugujeong Pavilion, Namyeogo Storage, office for the manager of Noksan, the brook on north and south, and the wall. It can be understood as a prototypical landscape composed of minimal facilities and the forest. Second, the northern palace walls of Gyeongbokgung Palace were constructed in King Sejong's reign. The area behind Yeonjo(king's resting place) up to Sinmumun Gate(north gate of the palace) was regarded as the rear garden when Gyeongbokgung Palace was constructed. However, a new rear garden was built outside the Sinmumun Gate when the palace was rebuilt. Only Noksan maintained the geomantic vein under the circumstance. However, the geographical features changed enormously during the Japanese colonial era when they constructed a huge official residence in the rear garden outside the Sinmumun Gate and the residence of the governor-general and road in the site of the Blue House. Moreover, Noksan was severed from the foothill of Baegaksan Mountain when 'Cheongwadae-ro(road)' was constructed between the Blue House and Noksan in 1967. Third, the significant characteristics and conditions of the forest, which became the origin of Noksan, were identified based on the fact that the geomatic state of the northeastern side of Gyeongbokgung Palace, the naecheongnyong area in geomantic terms(the innermost 'dragon vein' among the veins that stretched out from the central mountain toward the left side), and they planted pine trees to reinforce the 'ground vein' and the fact that it was expressed as the 'Pine Field' before the Japanese Invasion of Korea in 1592. The pine forest, mixed with oaks, cherries, elms, and chestnuts, identified through the excavation investigation, can be understood as the original vegetation landscape. Noksan's topography changed; a brook disappeared due to mounding, and foreign species such as acacia and ornamental juniper were planted. Currently, pine trees' ratio decreased while the forest is composed of oaks, mixed deciduous trees, some ailanthus, and willow. Fourth, the fact the name, 'Noksan,' came from the deer, which symbolized spirit, longevity, eternal life, and royal authority, was confirmed through an article of The Korea Daily News titled 'One of the seven deers in Nokwon(deer garden) in Gyeongbokgung Palace starved to death.'

• Journal of International Area Studies (JIAS)
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• v.14 no.1
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• pp.277-308
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• 2010

Since the globalization, many changes are occurring in our society. Multicultural phenonmenon in the society is becoming one of our major concern in the Korean society. Thus, this study is focusing on the multicultural phenomenon that we are facing since the globalization in Korea. No doubt that immigration is a growing force influencing the demographics of Korea. Since the mid-1990s, immigrant children and children from mixed marriage have become the fastest growing and the most extraordinarily diverse segment of Korea's child population. Until the recent past, Korea's major social attention has focused on adult immigrants to the neglect of their offspring, creating a profound gap between the strategic importance of the new second generation and the knowledge about its socioeconomic circumstances. In other words, there is a significant lack of studies on children of migrant, particularly from the Muslim background living in Korea. International marriage has grown rapidly in Korea since the late 1990s, and this phenomenon is especially common in rural farming communities. Most brides come from China, followed by Vietnam and other southeast Asian countries. However, there are certain number of Muslim bride coming to Korea. There are about 100 thousand muslim peoples living in Korean society. Among them 2.92% are Muslim immigrants' intermarriage with the Koreans. As a result, there are growing number of muslim brides and bridegroom settling in Korea, which would eventually create muslim families in growing korean multicultural societies. This study specify its research on the muslim mixed family by focusing on the offsprings of the muslim background. Our research team has created the new term on such research subject by using Koslim. Koslim is a 1.5 and 2^nd generation from the Muslim back ground family living in Korea. Thus, the objective of this study is to examine the awareness and the perception of Koslim by the Korean mainstream people. By doing so, it can analyze the general attitude of Koreans towards the Koslim people. In this sense this study intends to play a groundwork to promote successful coexistence between Korean and Koslim. It is anticipated that this research can lay the basis for Koreans to have more open and tolerant attitude towards our new members of society that is increasing everyday.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.3
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• pp.77-91
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• 2015

This study aims to suggest adequate soil management through the analysis of physicochemical properties of soil in the planting grounds of Incheon International Airport, which was constructed on a massive land reclamation site. Study areas were 5 sites at the international business complex, the passenger terminal, the airport support complex, the free trade zone, and the access road. Soil profile analysis showed that 9 plots out of the 27 plots were hardpan and heterospere within 80cm from the soil surface. The earth laid on the ground was categorized as gravel based soil(4 plots), dredged soil from the sea bottom and mixed reclamation materials(2 plots), clay with poor permeability(3 plots) and waste construction material(1 plot). Average soil hardness was $11.5kg/cm^2$ and soil textures were sandy soil, sandy loam and loamy sand. Average soil pH was 6.7 and average organic matter content was 0.7%. Electrical conductivity was 0.0dS/m and exchangeable cation concentrations were $Ca^{2+}$ 3.4cmol/kg, $Mg^{2+}$ 1.5cmol/kg, $K^+$ 0.3cmol/kg and $Na^+$ 1.0cmol/kg. Average cation exchange capacity was 11.0cmol/kg. Although average figures in Solum mostly meet the landscape design criteria, properties of each soil layer showed various values sometimes over the limit. Base saturations were $Ca^{2+}$ 29.9%, $Mg^{2+}$ 13.3% and $K^+$ 3.7% for lower soil, $Ca^{2+}$ 33.3%, $Mg^{2+}$ 17.0% and $K^+$ 2.7% for mid-soil and $Ca^{2+}$ 32.6%, $Mg^{2+}$ 12.2% and $K^+$ 1.9% for upper soil. Exchangeable sodium percentages were 16.4% for lower soil, 7.5% for mid-soil and 4.7% upper soil. Sodium adsorption rates were 0.8 for lower soil, 0.3 for mid-soil and 0.2 for upper soil. Factors affecting to the vegetation growth were heterogeneity and poorness of solum, disturbance of dredged soils, high soil hardness including hardpan in the subsurface soil layer and shallow effective soil depth, high soil acidity, imbalance of base contents, low organic matter content and low available phosphate levels in the soil.

• Korean Journal of Food Science and Technology
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• v.6 no.2
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• pp.116-123
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• 1974

1) In Seoul, it was known that the season for preparing Kimchies (fermented vegetables) for the winter was from the middle of November to early in December, in which the preparing rates of Kimchies in the middle of November, the end of November and early in December were 32.7%, 41.3% and 12.5%, respectively. The time that the largest quantity of them was prepared was about the end of November. 2) The average cost of Kimchies prepared for the winter for a family of four, five, six and seven was $10,000{\sim}15,000$ Won, $15,100{\sim}20,000$ Won, $10,100{\sim}20,000$ Won and $10,100{\sim}20,000$ Won, respectively, and the cost did not increase in proportion to members of a family. In case of the family of $6{\sim}7$, the cost for Kimchies showed a wide range compared with those for the family of $4{\sim}5$ 3) The main raw materials of kimchi for one person for the winter required $12{\sim}20$ heads of Chinese cabbages, $14{\sim}20$ roots of radishes, $4{\sim}7$ cloves of garlics and $300{\sim}500g$ of powdered red pepper. 4) The residents living in Seoul had prepared the several kinds of the pickles for the winter as follows; (1) Chinese cabbage Kimchi (98.9%), (2) Whole Chinese cabbage Kimchi (74.7%), (3) Kkakdugi (68.6%), (4) Dongchimi (66.4%) and (5) Chong-kak Kimchi (63.3%). It has, therefore. been considered that the five kinds of Kimchies mentioned above may be industrialized. 5) Uniqueness of the raw materials used for the most popular Chinese cabbage Kimchi was to use leeks, garlics, red peppers and gingers as spices, and it was also known that proper amounts of salted shrimp pickles and oysters was mixed to the Kimchies. Therefore, it had been considered that the characteristics of Chinese cabbage Kimchies for the winter had the hot taste with freshness. 6) For keeping the Kimchies during the winter about the half of the pickle jars was buried in the ground, and another half of them were wrapped in the straw bags or styropol and they were placed on the ground or kept in the basement, 7) In most case (80.9%), the salt concentration of pickling was adjusted by one's experiences, and only 19% of them was measured with the instruments. 8) Most of remaining kimchies were usually used for other cooks, but some of them were thrown away. 9) The ratio of the people who had ever bought the market Kimchies for their own edibility was 17.8% and most of them got it only in the spring and summer season. 10) About 18% of the residents living in the general houses in Seoul had ever bought the market Kimchies. It was also known that about 48% of the residents living in the general houses and about 79% of the residents living in the apartments wanted to purchase the market Kimchies if the production of the delicious Kimchies were industrialized. The season that the people wanted to get the market Kimchies was a little different each other among the residents. About 13.4% of the residents living in the general houses wanted to purchase the Kimchies during the summer, and 11.9% of them wanted to get it throughout the year. On the other hand, in case of the apartments, 25.2% of the residents wanted to get it during the summer and 24.4% of them wanted it throughout the year (4 seasons) and 19.9% of them wanted it during two seasons. The data mentioned above have shown that many residents hope strongly an industrial production of the Kimchies. It is also true that many residents living in both the general houses and apartments want to get the market kimchies throughout the year, and particulary during the summer season that most foods are very apt to be spoiled.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.116-123
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• 2004

This study was conducted to investigate the changes in physicochemical and microbiological properties during fermenting process of organic fertilizer which was made from the mixture of organic materials such as sesame oil cake, fish meal, blood meal, rice bran, ground bone meal, and natural minerals such as illite, crusted oyster shell and loess. They were mixed and fermented for 70 days. The sesame oil cake and rice bran, major ingredients for organic fertilizers, consisted of 7.6 and 2.6% total nitrogen, 3.6 and 4.6% $P_2O_5$, 1.4 and 2.2% $K_2O$, respectively. The ground bone meal included 29.2% $P_2O_5$ and illite included 3.8% $K_2O$. Temperature of organic fertilizer during the fermentation rapidly increased over $50^{\circ}C$ within 2 days after mixing and stabilized similar to outdoor temperature after 40 days. Moisture content decreased from 36.3 to 16.0% after 1 month. C/N ratio of organic fertilizer slightly increased until 30 days and thereafter, it slowly decreased, It resulted from the faster decrease of total nitrogen concentration compared with organic matter. Concentration of $NH_4-N$ in organic fertilizer rapidly increased from 1,504 to $5,530mg\;kg^{-1}$, the highest concentration after 10 days. Meantime, $NO_3-N$ concentration was low and constant about $150mg\;kg^{-1}$ over the whole fermenting period. This result seemed to be due to the high pH. The organic ferfilizer fermented for 70 days was composed of 2.7% N, 2.8% $P_2O_5$, 1.8% $K_2O$, and 35.9% organic matter. Total populations of aerobic bacteria, Bacillus sp. and actinomycetes, after fermenting process, were $12.5{\times}10^{10}$, $45.5{\times}10^{5}$ and $13.6{\times}10^{5}cfu\;g^{-1}$ respectively. Pseudomonas sp. was $71.9{\times}10^{7}cfu\;g^{-1}$ at first, but it rapidly decreased according to the rise of temperature. Yeasts played an important role in the early stage of fermentation and molds did in the late stage.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.504-519
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• 2020

Oceanic fronts, which are areas where sea water with different properties meet in the ocean, play an important role in controlling weather and climate change through air-sea interactions and marine dynamics such as heat and momentum exchange and processes by which properties of sea water are mixed. Such oceanic fronts have long been described in secondary school textbooks with the term 'Jokyung water zone (JWC hereafter) or oceanic front', meaning areas where the different currents met, and were related to fishing grounds in the East Sea. However, higher education materials and marine scientists have not used this term for the past few decades; therefore, the appropriateness of the term needs to be analyzed to remove any misconceptions presented. This study analyzed 11 secondary school textbooks (5 middle school textbooks and 6 high school textbooks) based on the revised 2015 curriculum. A survey of 30 secondary school science teachers was also conducted to analyze their awareness of the problems. An analysis of the textbook contents related to the JWC and fishing grounds found several errors and misconceptions that did not correspond with scientific facts. Although the textbooks mainly uses the concept of the JWC to represent the meeting of cold and warm currents, it would be reasonable to replace it with the more comprehensive term 'oceanic front', which would indicate an area where different properties of sea water-such as its temperature, salinity, density, and velocity-interact. In the textbooks, seasonal changes in the fishing grounds are linked to seasonal changes in the North Korean Cold Current (NKCC), which moves southwards in winter and northwards in summer; this is the complete opposite of previous scientific knowledge, which describes it strengthening in summer. Fishing grounds are not limited to narrow coastal zones; they are widespread throughout the East Sea. The results of the survey of teachers demonstrated that this misconception has persisted for decades. This study emphasized the importance of using scientific knowledge to correct misconceptions related to the JWC, fishing grounds, and the NKCC and addressed the importance of transferring procedures to the curriculum. It is expected that the conclusions of this study will have an important role on textbook revision and teacher education in the future.

• Journal of Plant Biotechnology
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• v.38 no.3
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• pp.221-227
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• 2011

This study was carried out to determine optimal medium conditions for mass propagation by bioreactor culture of ever-bearing strawberry (Fragaria ${\times}$ ananassa D.). Two different type of nitride were that mixed $NH_4NO_3$ and $KNO_3$ or added $KNO_3$ only. And nitride concentrations were at the 4 levels of $1/2{\times}$, $1{\times}$, $2{\times}$ and $3{\times}$ that was included $NH_4NO_3$ and $KNO_3$. Sucrose content ranged at 3 levels of $10g{\cdot}L^{-1}$, $20g{\cdot}L^{-1}$ and $30g{\cdot}L^{-1}$ and medium pH were at the 3 levels of 4.6, 5.6 and 6.6. In bioreactor culture, medium that are included $NH_4NO_3$ and $KNO_3$ together in MS medium was suitable for mass propagation. Medium EC rose rapidly when the nitride concentration was increased. For that reason, plantlet growth was inhibited. Shoots of nitride $1/2{\times}$ concentration was 10.8 ea and $1/2{\times}$ concentration was suitable for shoot propagation. Fresh weight of sucrose $30g{\cdot}L^{-1}$ was 3,101 mg which was heaviest and aerial and ground part were higher than the other concentration. Shoots were increased in proportion to the increasing concentration of sucrose. In the pH condition, from pH 5.6 to 6.8 were appropriate for the optimum growth of aerial and ground part of plant. From the results, in bioreactor culture for mass propagation, MS medium was suitable $1/2{\times}$ concentration that was included $NH_4NO_3$ and $KNO_3$ together, and added $30g{\cdot}L^{-1}$ of sucrose, and then adjusted pH between 5.6 and 6.6.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.4-23
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• 2013

Songsalli Ancient Tombs of Gongju consists of seven tombs. King Muryeong's tomb, the seventh tomb, is a brick chamber tomb discovered during the drainage works for the fifth and the sixth tombs in 1971. The excavation at the time focused on topographic surveys of the tomb entrance and the inside of the burial chamber as well as collection of the remains. The burial mount survey confirmed the status of some stone slab remaining and lime-mixed soil layers, but the survey did not examine the exterior structure of the whole tomb as the mounds were removed even more deeply. The excavation revealed damages to the bricks and mural damages due to moisture and fungus in the sixth and the seventh tombs. Between 1996 and 1997, Gongju National University conducted a comprehensive detailed survey of Songsalli Ancient Tombs including a geophysical survey, with an aim to identify the root causes of such degradation. Based on the results, repair took place in 1999 and the fifth, sixth and seventh tombs were placed under permanent conservation to conserve the cultural assets. General public is currently denied access. The purpose of this study was to conduct a three-dimensional resistivity and GPR surveys on the ground surface of the fifth, sixth and seventh tombs of Songsalli Ancient Tombs in order to understand the underground status after repair. The study also aimed to understand the thickness of all the tomb walls and exterior structure based on GPR inside King Muryeong's tomb. The exploration on the ground surface found that the three tombs and soil adjacent to the tombs had resistivity as low as 5 to $90{\Omega}m$, which confirmed that the soil water content was still as high as that prior to the repair work. Additionally, GPR found that the wall construction of the burial chamber of King Muryeong's tomb was approximately 70cm in thickness, while the structure was of 2B with two bricks, about 35cm in length, put together longitudinally(2B brick masonry). The pathway to the burial chamber was of the 2B structure just like that of the burial chamber walls, while its thickness was 80cm with an eyebrow-type arch connected to it. Also, the ceiling exterior appears to have an arch structure, identical to the shape inside.