• The Korean Journal of Ecology
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• v.22 no.5
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• pp.277-285
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• 1999

To develop a better restoration technique for altering urban planted forest to more natural forest, the changes of flora, vegetation structure and woody plant growth in the early stage after lumbering only Populus albaglandulosa of the tree layer were studied in Chungdam Park, Chungdam-dong, Kangnam-gu, Seoul for two years (from 1997 to 1998). The results were as follow. First, in the year after lumbering, the species changes occurred not in woody plants but in herbs, which increased by 44%. Three species including Viola verecunda disappeared, and 15 species including ruderals such as Metaplexis japonica and introduced species such as Erechtites hieracifolia appeared newly. Second, lumbering caused the coverages of Quercus aliena, Q. mongolica, Q. acutissima and Sorbus alnifolia in the subtree, or shrub layer, to be increased abruptly. The coverage of Lespedeza bicolor was affected by neighboring plants. Third, in the herb layer the coverage of Artemisia keiskeana was conspicuously increased but those of the others were not. Fourth, by ridding the upper layer canopy, Quercus' growth rates were increased highly. Rates of DBH growth of Q. aliena, Q. mongolica and Q. dentata were increased to 53.0%, 22.9% and 8% in the experimental area, and 23.1%, 8.3% and 6.1% in the control area, respectively, during two growing seasons (from May 11, 1997 to October 27, 1998). The ratios of twig biomasses of the previous year to the next year were 100:565 in Q. aliena, 100:197 in Q. mongolica and 100:644 in Q. dentata in the experimental area. There were also growth ratios of 100:117 in Q. aliena, 100:100 in Q. mongolica and 100:42 in Q. dentata in the control area, respectively. The growth rate increases of Q. aliena and Q. dentata were thus conspicuous in twig rather than in trunk, but that of Q. mongolica was vice versa.

• The Journal of the Acoustical Society of Korea
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• v.37 no.5
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• pp.378-386
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• 2018

The present paper suggests the original form of the bell pavilion for the King Song-Dok bell which is one of the precious national treasure of Korea. In order to this, many literatures were reviewed including both historical and acoustical references. As the results, the model of the bell pavilion for the King Song-Dok bell is suggested as follows considering acoustical characteristics of the King Song-Dok bell and the traditional Korean bells ; 1) The bell pavilion has the rumbling puddle beneath the bell on the ground floor for resonance of sound 2) Many lumbers are used for columns and beams rather than boards since natural frequencies of the bell are 64 Hz and 168 Hz so that the sound absorption of the low frequency sound may not be occurred. 3) Only some boards may be used for the area between upper and middle molding of lintel in order to prevent of direct sunlight and sea breeze since this type of structure were used for bell pavilion of the same age. 4) Square form with the odd number of 3 or 5 Kans is adopted for bell pavilion considering the weight and the size of the bell which had been used traditionally 5) Finally, half-hipped structure is used for the roof of the bell pavilion which was the predominant form of the age.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.6
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• pp.199-208
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• 2013

The purpose of this study is to compare the vegetation structure in complementary forests of villages between Korea and China. For this study, Jinan in Korea and Qingzhou in China were selected through a pre-survey about the representative regions of both countries. The main research method used was field study. A comparative analysis between the two regions was performed by a frequency analysis of the surveyed data. The data obtained in the study shows the vegetation structure in complementary forests of villages in the two regions have many differences which are related to the local culture. As a result, it was identified that the average number of species was the same at 2.9 and the average number of trees, total number of trees, and tree density in Qingzhou were considerably greater than those in Jinan. Also, it was identified that tree height, average breadth height diameter and crown width in Jinan were considerably greater than those in Qingzhou. Furthermore, it was identified that both the forest state and the principal species of tree are both very different according to the different cultures. Through this identification, it is considered that this study will be helpful in establishing policy direction in both countries about the restoration and management of complementary forests.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.129-144
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• 2010

We have studied the changes of the environmental and vegetational factors according to the hydro-seral stages in the shoreline of the lagoons, Korea. We have divided seral stages into 7 stages from open water stage to the stratified forest stage considering as the characteristics of water body, dominance of submerged and emergent plant, and development of the shrub, subtree and tree layer. According to the successional stage, water depth gradually decreased and water quality changed from seawater to brackish water and from brackish water to fresh water, organic matter in a soil layer gradually increased, and the litter layer grew up. As the development of the vegetation structure, the life-form of the vascular plants changed as follows; open water ${\rightarrow}$ submerged plant and floating-leaved plant ${\rightarrow}$ emergent plant and submerged plant ${\rightarrow}$ emergent plant ${\rightarrow}$ emergent plant, mesophyte and scrub ${\rightarrow}$ mesophyte. In the late seral stage, the 3 different forest types were established by the water retention or drainage and nutrient accumulation of the soil layer. Salix dominant forest developed in the wetted sites, the forest type dominated by Pinus thunbergii, Carex pumila and mesophytes developed in the well drained sites causing by sand substrate, and the forest type dominated by the planted or ruderals such as Pinus densiflora, Robinia psedo-acacia, Festuca ovina, Setaria viridis ect. developed in the sites composed of forest soil introduced by artificial reclamation.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.46-63
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• 2012

The object of this study was to analyze the speciality of Korean traditional waterscape and unique landscape formed with reflection of the phases of the time sat the area of Juhabru(宙合樓) in Changdeok Palace as a basic research to find the prototype of Taeaek pond at Changdeok Palace and restoration of the palace. Originally, Taeaek pond at Changdeok Palace was constructed in KingInjo(仁祖) period as a name of Yongji(龍池), later it called Taeaek pond after King Sukjong(肅宗). There is an island as a symbol of the immortal isle, and Chungseojeong(淸署亭), Taiksujae(澤水齋) and Buyongjeong(芙蓉亭) which were built to view the waterscape in Taeaek pond. Buildings were built asymmetrical balance around Taeaek pond because of the morphological character of tetragonal pond. Arrangement of this area has a definite form of axial structure. Yeolgokwan(閱古觀) Gaeyuwa(皆有窩), pavilions, bridges, islands, Osumoon(魚水門) and Juhabru are located on the north and south axis, and island and Osumoon play a role as a intersection and form an east of west axis. In this study, manual of construction for an island and pavilions is provided by analyzing transformational process of island and pavilions at Taeaek pond. Furthermore, kings and officials used to statically enjoy the view around Taeaek pond area, but dynamic fishing and boating activity happened in King Jungjo(正祖) period. These historical backgrounds have an influence on the spatial organization of Taeaek pond. For instance, bridge between Taeaek pond and island was destroyed with the increase of the importance of boating. Symbolic structure around Taeaek pond means 'fish changes to dragon' and 'both of king and officials become one'. Taiksujai, carving fish, Osumoon and Juhabru are provided as a related spatial factors.

• Korean Journal of Environment and Ecology
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• v.10 no.1
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• pp.66-75
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• 1996

To propose basic information for national resource management and planting disign, plant community structure of evergreen broad-leaved forest was investigated. Fifty-two plots(each size 300m$^{2}$) were set up at Ch'omch'alsan area of Chindo, Korea. TWINSPAN and DCA methods were used for classification and ordination analysis. Fifty-two plots were divided into seven groups, which were Quercus variabilis-Carpinus tschonoskii community, Q. glauca community, Castanepsis cuspidata var. sieboldii-Q. stenophylla community, Castanopsis cuspidata var. sieboldii-Camelia japonica community, Q. acuta-Camelia japonica community, Carpinus coreaca-Q spp. community, C. coreana community. Pinus densiflora almost have been selected. Carpinus tschomoskii, Q. variabillis and Q. serrata were to be succeeded by Castanea cuspidata var. sieboldii, Q. stenophylla, Q. acuta and Neolitsea sericea in canopy layer. And Neolitsea sericea, Q. glauca and Camellia japonica was showed high importance values in fertile soil condition. Future restoration plan was necessary for a tourist resort or national forest in warm temperate region. And evergreen broad-leaved plants shall be planted in considering of environmental condition at warm temperate and industrial complex area.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.2
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• pp.143-166
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• 1999

The success of porcelain laminate veneer depends on the bond strength between tooth structure and ceramic restoration and the design of tooth preparation. In particular, incisal coverage and incisal finish line are the two most important factors in long-term fracture resistance. Although the majority of clinicians are practicing incisal coverage and there are various opinions on the geo-metrical ratio between the clinical crown length of the remaining tooth structure and the length of incisal extension in porcelain laminate veneer and the optimal incisal finish lines. scientific evidence still loaves much to be desired. The purpose of this study was to determine the effects of the amounts of incisal coverage and the types of incisal finish line on the stress distribution in maxillary anterior porcelain laminate veneers under two different loading conditions. Three-dimensional finite element models of a maxillary anterior porcelain veneer with differ-ent amounts of incisal coverage ; 0, 1, 2, and 3mm and different incisal finish lines feathered edge, incisal bevel, reverse bevel and lingual chamfer with various amounts of lingual extension were developed. 300N force was applied at the point 0.5mm cervical of the linguoincisal edge in two loading conditions ; A) 125 degrees, B) 132 degrees. Tensile and compressive stress in ceramic and shear stress in the resin cement layer were analyzed using three-dimensional finite element method. The results were as follows : 1. The types of incisal finish line had more influence on the stress distribution in porcelain laminate veneer than the amounts of incisal coverage. 2. In case of no incisal coverage, incisal beveled laminate exhibited more evenly distributed tensile stress than feathered edged laminate. And in case of incisal coverage, reverse beveled laminate and lingual chamfered laminate with 1mm lingual extension exhibited more evenly distributed tensile stress than lingual chamfered laminates with 2mm and 3mm lingual extension. 3. As long as the lingual chamfer goes, less tensile stress was found at the incisal edge, while much more tensile stress was found at the lingual margin area in proportion to the length of lingual extension. 4. Under 125 degree load, tensile stress in porcelain laminate veneer had increased compared with that under 132 degree load and the difference exhibited by the change of the amount of tooth support was larger. 5. The types of incisal finish line and the distance from the incisal finish line to the loading point had more influence on the shear stress distribution in the resin cement layer than the amounts of incisal coverage. In contrast loading condition had little influence.

• Journal of Periodontal and Implant Science
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• v.37 no.2
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• pp.209-221
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• 2007

Recently, immediately after losing teeth. implant placement has been greatly attempted. Implant can help restoration of tooth functions within short time. This study was an attempt to examine the extent of osseointergation when the implants will be placed immediately after teeth extraction using domestic implant systems. Implants were inserted in beagle dogs and evaluated the clinical, radiological, histological and histomorphometric assay at 6 weeks and 12 weeks. For experimental materals, $STAGE-1^{(R)}$($4.1{\times}8mm$, Lifecore, USA), $SS-III^{(R)}$($4.0{\times}8mm$, OSSTEM, Korea) and $IFI^{(R)}$($4.0{\times}8mm$, Dio, Korea) implants treated with RBM were placed. All the placed site showed normal results without fail and inflammation clinically and radiologically. As a result of measurement by periotest, it showed $-2\;{\sim}\;-5$ and stable status comprehensively. There was no statistically significant difference among implants(p<0.05). Bone tissue adjacent to implant showed increased marrow tissue at 6 weeks. Nevertheless, osteogenic structure was not observed remarkably. In a 12 weeks opinion, bone tissue composed of osseointegration along implant interface showed significantly decreased marrow tissue containing central vessels unlike a 6 weeks opinion and matured compact bone whose osteogenic structure is well formed. BIC were 42.4%, 32.0% and 34.9%, respectively in 6 weeks and there was no statistically significant difference among group(p<0.05). In 12 weeks, BIC were 58.8%, 61.9% and 57.5%. respectively and there was no statistically significant difference among groups(p<0.05). It is considered that all 3 implant systems are suitable for immediate implant placement.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.3
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• pp.103-111
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• 2016

Seasonal dynamics of kelp forest-forming algae, Ecklonia cava population formed following the large-scale disturbance by Typhoon 'Bolaven' in August 2012 were investigated in Jeju Island, Korea. Morphological characteristics, recruits density, mortality rate, total density and biomass were monitored bimonthly from June 2013 to June 2015. Total and longest blade lengths, and individual weight of E. cava showed distinct seasonal trends. Stipe length increased from winter to spring, but did not show increase or reduced from summer to autumn. This indicates that morphological characteristics of E. cava are mainly affected by the change of blades. The optimal temperature for E. cava growth was about $15-18^{\circ}C$ during winter to spring while the growths were inhibited at the water temperature above $20^{\circ}C$ during summer. E. cava exhibited very low recruitment during spring-summer. However, high recruitment was observed on April 2015 when canopy cover was very low due to low density. This indicates that recruitment of E. cava was controlled not by seasonal effects but by physical factors such as canopy and space. The mortality rate of juvenile plants was highest due to their unstable settlement. By June 2015, 34 months after the disturbances, E. cava was almost recovered to the pre-disturbance population size structure. These results suggest that recovery of kelp forest following the large-scale disturbance requires a considerable period of time (more than three years). This study should provide valuable ecological information on management, restoration and protection of kelp species.

• Korean Journal of Environment and Ecology
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• v.24 no.4
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• pp.351-362
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• 2010

This study was supposed to offer vegetation plans for functional improvement of the recreational forest by researching Mt. Chukryong which is located at Oebang-li Sudong-Myon Namyangju Kyong-gi Province in Korea. In this study, artificial vegetation and natural vegetation near trails in recreational forest were researched through biodiversity analysis. From this analysis process, a typical management improvement of the biodiversity functions were examined by reviewing functions biotope condition, vegetation structure and wild bird community condition. Typical vegetation system was divided into four detail parts: Managed artificial Pinus koraiensis forest, Not managed artificial Pinus koraiensis forest, Natural deciduous forest and Not managed deciduous forest. As a result of the vegetation structure, the numerical value of the deciduous forest species diversity was higher than that of artificial Pinus koraiensis, and the numerical value of the managed condition was higher than that of not managed condition. As a result of a habitat structure analysis of the wild bird community, managed Pinus koraiensis forests were inadequate structure for wild birds to habit in there because the forests had weak structure layers, but unmanaged deciduous forest and unmanaged Pinus koraiensis that had diverse layers was proper places for birds to in habit. Thus, based on the functional analysis of biodiversity, management patterns of the target area were concluded in two manners: conserving management and restoring management. Deciduous forest protection target areas included natural deciduous forest area and managed deciduous forest area, ecological restoration target area included unmanaged artificial Pinus koraiensis area and restoring management target area includes managed artificial Pinus koraiensis.