• Journal of Korean Society of Forest Science
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• v.107 no.2
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• pp.193-204
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• 2018

This study was carried out to select the optimal method of competition index computation according to the competitor selection methods and distant-dependent competition index models, and to analyze the characteristics of competition indices in terms of thinning intensity and tree density targeting Pinus densiflora, Pinus koraiensis, and Larix kaempferi, which are the major coniferous species in Korea. Data was the re-investigated tree information from 240 permanent plots of 80 sites in the stands of P. densiflora, P. koraiensis, and L. kaempferi, which were located in the national forest of Gangwon and North Gyeongsang provinces. The number of subject trees with competition index calculated were 1126 trees for P. densiflora, 4093 trees for P. koraiensis, and 3399 trees for L. kaempferi. For the best competition index computation method, three kinds of competitor selection methods were considered: basal area factor, angle of height, angle of height to crown base. Also, six kinds of competition index models were compared: Lorimer, Martin-EK, Braathe, Heygi, Daniels, and Modified Daniels, which was developed in this study. Correlation coefficient was the best when the competitor selection method of basal area factor $4m^2/ha$ and the competition index model of Modified Daniels were used, and thus, it was selected as the best method for computing competition index. According to the best method by stand characteristics, competition index decreased in all species as thinning intensity was high and tree density was low.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.105-112
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• 2017

In order to analyze the effect of street trees on human thermal sensation(thermal comfort) in summer, microclimatic data were measured and analyzed at sunny and shaded locations of two deciduous broadleaf and three broadleaf evergreen species of street trees. As a result, the mean differences by species in air temperature, relative humidity and wind speed were small: $0.2{\sim}1.5^{\circ}C$, 0.9~5.3% and $0.1{\sim}0.5 ms^{-1}$, respectively, but the mean difference in the mean radiant temperature was great, $27.1^{\circ}C$. In the results of physiological equivalent temperature(PET) and universal thermal climate index(UTCI), which are human thermal sensation(thermal comfort) indexes, the shaded locations by the trees showed mean reduction rates of 21.2~31.3% in the PET compared with the sunny location, which are equivalent to 1.5~2.5 levels of thermal perception. Also, 12.7~20.0% in the UTCI was reduced by the trees' shadows, which is equivalent to 1~1.5 levels of heat stress. In addition, although the broadleaf evergreen trees had 5% greater mean reduction in PET than that of the deciduous broadleaf trees, the Zelkova serrata that belonged to the deciduous broadleaf trees showed the equivalent thermal reduction effect as the broadleaf evergreen trees because of the high density of branches and leaves. Therefore, the mean radiant temperature and the density of the crown(branches and leaves) were the main influences in thermal modification by these street trees in summer.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.248-254
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• 2005

The purpose of this study was to investigate the distribution of stress within the regenerated bone surrounding the implant using three dimensional finite element stress analysis method. Using ANSYS software revision 6.0 (IronCAD LLC, USA), a program was written to generate a model simulating a cylindrical block section of the mandible 20 mm in height and 10 mm in diameter. The $5.0{\times}11.5-mm$ screw implant (3i, USA) was used for this study, and was assumed to be 100% osseointegrated. And it was restored with gold crown with resin filling at the central fossa area. The implant was surrounded by the regenerated type IV bone, with 4 mm in width and 7 mm apical to the platform of implant in length. And the regenerated bone was surrounded by type I, type II, and type III bone, respectively. The present study used a fine grid model incorporating elements between 250,820 and 352,494 and nodal points between 47,978 and 67,471. A load of 200N was applied at the 3 points on occlusal surfaces of the restoration, the central fossa, outside point of the central fossa with resin filling into screw hole, and the functional cusp, at a 0 degree angle to the vertical axis of the implant, respectively. The results were as follows: 1. The stress distribution in the regenerated bone-implant interface was highly dependent on both the density of the native bone surrounding the regenerated bone and the loading point. 2. A load of 200N at the buccal cusp produced 5-fold increase in the stress concentration at the neck of the implant and apex of regenerated bone irrespective of surrounding bone density compared to a load of 200N at the central fossa. 3. It was found that stress was more homogeneously distributed along the side of implant when the implant was surrounded by both regenerated bone and native type III bone. In summary, these data indicate that concentration of stress on the implant-regenerated bone interface depends on both the native bone quality surrounding the regenerated bone adjacent to implant and the load direction applied on the prosthesis.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.590-600
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• 2021

This study compared the stand structure of Abies koreana forests between Mt. Jirisan and Mt. Hallasan by analyzing DBH distribution, stem vitality, crown structure, importance value, species diversity, and DCA. The data were acquired through the national long-term ecological research project conducted by the Ministry of Environment. In the comparison of DBH class distribution, the stem density of A. koreana with DBH < 20 cm was higher in Mt. Hallasan than that in Mt. Jirisan; however, the stem density of A. koreana with DBH > 20 cm was higher in Mt. Jirisan than that in Mt. Hallasan. For A. koreana stem vitality, the ratio of alive standing was higher in Mt. Jirisan (72.0%) than in Mt. Hallasan (60.7%), whereas the ratio of alive leaning was higher in Mt. Hallasan (10.2%) than in Mt. Jirisan (1.1%). A. koreana stand in Mt. Jirisan was a mature stand with four evenly developed and distinct layers, whereas the tree layer in Mt. Hallasan was less than 10 m and the stand had three layers without a subtree layer. Mt. Hallasan's importance value of A. koreana was 39.4% higher than Mt. Jirisan's importance value of 26.6%. The species diversity of the A. koreana community of Mt. Jirisan was 2.52 times higher than that of Mt. Hallasan, which was 1.58. DCA results revealed that the average distance between Mt. Jirisan and Mt. Hallasan was relatively distinguished, and the degree of scattering of species composition of Mt. Jirisan was relatively dense compared with that of Mt. Hallasan.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.497-503
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• 2022

This study was conducted to investigate the horticultural media + decomposed granite + reused rock wool in the following mixing ratio: Control = 100:0, M1 = 80:0:20, M2 = 60:30:10, M3 = 40:30:30, M4 = 30:40:30, M5 = 0:50:50 (reused rockwool : decomposed granite : horticultural media) and develop the physicochemical properties and the growth of 'Sulhyang' strawberry runner plant. In the physical aspect of the horticultural media, statistical differences were recognized that the bulk density and particle density were lower in the control and M1. But the bulk density and particle density were high in the M3, M4, and M5, because it had high mixing ratio between recycled rock wool and decomposed granite. EAW and WBC showed a similar tendency. The air porosity and total porosity were higher in control and M1 than M3, M4, M5. Exchangeable cation (K⁺, Ca²⁺, Na⁺, Mg²⁺) and base replacement capacity (CEC) were higher in control and M1, than M2, M3, M4, and M5. As a result of the cultivation of 'Sulhyang' runner plant, the plant length was long in M2, 32.1 cm and smaller than M5 to 28.4 cm. However, if the crown diameter, which is the growth indicator of the runner plant, all 6 treatments were formed 11.23 mm-12.03 mm, which is considered to be suitable for the growth of the runner plant. There wasn't a statistical difference between the weight and dry weight of the root. As a result, the growth difference of the seedlings by the horticulture media was similar. Therefore, considering the physical properties of the horticultural media, it was judged that the air porosity and total porosity would be improved when the recycled rock wool and the decomposed granite were properly mixed rather than the use of the horticultural media as a single medium, which would be advantageous for irrigation management.

• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.342-356
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• 2014

This study aims to provide the fundamental data for restoration through the analysis of vegetation structure characteristic for managed area with deforest and fumigation among the places damaged by oak wilt disease in Bukhansan National Park. Study areas were selected in six damaged areas with 18 plots ($20m{\times}20m$) including comparing plots between year 2006 and year 2011 after preliminary study finding the exact location with easy access. Analysis items are density and coverage of under story layer, Importance Percentage of under story layer and Importance Percentage of urban adapted species and alien species. As a result, density and coverage under the canopy layer's vegetation was higher than comparing plot in Musugol valley and Soquicheon valley which 4 years and more passed. And Wondobong, Darakwon, Doseonsa and Dobong valley which had not been passed 3 years after deforestation and fumigation decreased in those of vegetation. However, the plots in Wondobong and Doseonsa was analyzed to be higher in density of shrubs than comparing plot. In terms of distirbution of species in under canopy layer which is grown as a upper vegetation, Quercus serrata and Sorbus alnifolia dominated each other in under canopy layer except for Wondobong and Darakwon. Wondobong continuously maintained Quercus mongolica and Q. mongolica and Pinus densiflora dominated in under canopy layer of Darakwon. S. alnifolia which is Urban adapted species were distributed in most study areas. In terms of alien species, Magnolia obovata and Robinia pseudoacacia were newly intruded in the opened crown, and Pueraria thunbergiana was distributed in Soquicheon valley. As the result of soil analysis, acidification(pH 4.49) and low level of organic matter(3.23%), available phosphate(1.40mg/kg) and exchangeable cation were analyzed and it was considered that those environment poorly support the vegetation growth.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.457-471
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• 2014

This study aims to present an evaluation scheme to improve the problems in tree shapes and tree growth which were identified through shape and growth assessments of landscape trees currently planted in Haedoji Park, Songdo, Incheon Metropolitan City after plant structure status and propriety review for funtion of space and concept of planting. Suitability the planting concept was evaluated according to function of space. The result indicated that the shade planting areas accounted for 29.5% of the the shade spaces area. 58.7%, respectively planting areas of visual landscape. And 11.8%, respectively planting areas of buffer. Because the planting areas was lacked according to the park established spatial configuration of central facilities and the result of plant young trees. Plant structure status required consideration with plant structure, density, size, growth status for improve planting function. The tree assessment was performed on a total of 28 species and 600 trees of which 22 species and 209 trees were planted in the buffer zone, 8 species and 71 trees in the shade zone, 16 species and 266 trees in the visual landscape zone, and 4 species and 54 trees in the ecological landscape zone. The trees were divided into grades based on their assessment score and were statistically grouped by the functional zone in where they are planted and by tree species to verify their significance. The tree shape assessment was an average of 56.6 points and the tree growth assessment was an average of 76.0 points. Using the results of the tree assessments, the tree standards for each functional space were identified and a concept of optimum planting and cultivating was applied. When applying the shape assessment results by zone to the concept of planting, since trees for buffering require high functionality they received E's, the lowest grade; as trees for ecological landscaping require diverseness and naturalness, they received D's; since trees for shading require utilization, they received C's as trees with branching at the main stems were considered; and since trees for visual landscaping required aesthetical value, they received A's and B's. When applying the growth assessment results by zone to the concept of planting, based on planting foundations of favorable and poor, for buffering, visual landscaping, and ecological landscaping, trees from grades A to E could be planted, and for shading, trees from grades A to C could be planted. For a cultivation plan that could improve the growth of the trees, we proposed that the topography of the land be selected considering the tree's characteristics and that a method of pot seeding be used. Also, to improve the shape of the trees, we proposed that poles be used to improve the growth of vertically-straight stems, an appropriate planting density be applied for reasonable branch growth, manage tree shape to maintain good crowning, and better manage fertilization to maintain a reasonable crown density.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.278-286
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• 2008

Many studies regarding Casein phosphopeptides-amorphous calcium phosphate(CPP-ACP) have demonstrated the remineralization ability on the demineralized enamel surface. A question is still remained that how deep can the calcium (Ca) and phosphorus (P) ions supplied by the CPP-ACP paste penetrate into the enamel subsurface. The aims of this study were to measure the penetrating depth of Ca and P ions in the demineralized human enamel in vitro, and were to determine the amount and depth of Ca and P ions according to the duration. The amount and depth of Ca and P ions were measured by microscopic observation with Field Emission Scanning Electron Microscopy (FE-SEM; LEO SUPRA 55, Carl Zeiss, Germany) and Energy Dispersive X-ray Spectrometer (EDS; GENESIS 2000, EDAX, USA: Linescan of Calcium and Phosphorus). Freshly extracted four human 1st premolars were obtained from the Dept. of Pediatric Dent., Kyung Hee Univ. Buccal surfaces of the 1st premolars were covered with nail varnish to form a window on the middle third of buccal surface. All of the teeth with enamel windows were immersed in a solution of 0.1 M lactic acid, Carbopol C907 (carboxypolymethylene BF Goodrich, Cleveland, OH, USA) at pH 4.8, and then incubated for 7 days. Each tooth crown was sawn in half through the midline of buccal window along the long axis of premolar. The four blocks of premolars were immersed in a 10-times diluted solution of CPP-ACP paste (Tooth Mousse, GC Corp., Tokyo, Japan) for 1, 2, 3 and 5 weeks while the rests were immersed in a placebo solution (distilled water) for the same duration. Each specimen was embedded in epoxy resin, and was sectioned perpendicular to the window, using a water-cooled diamond blade saw. The spectrum density indices of Ca and P were measured in the sound, de- and remineralized enamels by FE-SEM and EDS. The Student's t test was performed to compare the Spectrum Density Indices (SDI) of sound, re-and demineralized enamels, and to compare the differences among the durations. Followings are the conclusion : 1. The penetration depth of the remineralizing ions (Ca & P) of CPP-ACP paste is related to the depth of demineralized enamel (approximately $1050{\sim}1350{\mu}m$). It is revealed that the penetration depth of both ions reaches full thickness of decalcification and even slightly into the sound enamel. 2. The Ca & P levels of remineralized enamels in 1, 2 weeks were significantly higher than those of the sound enamels (p<0.05). 3. No statistically significant difference of Ca & P levels was found in relation with the increasing duration of remineralization (p>0.05).

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.3
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• pp.1-11
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• 2013

In this study, based on a natural monument forest research by Camellia japonica L. Forest appointed as a natural monument located environment and growth environment and the soil environment, Camellia japonica L. Forest soil in order to analyze effects of soil in Camellia japonica L. Forest correlation analysis the results can be summarized as follows: First, a natural monument Camellia japonica L. forest located on the foot of a mountain valley or within the stream, a lot of sunshine southeast, east, and south in the direction of the share due to external factors, making it a good, but, $15{\sim}30^{\circ}$ of distributed in the soil slopes in the slope there is a risk of loss are appearing. Second, the growth of the Status of Camellia japonica L. forest represents the distribution of the uneven-aged forest diameter class. but increases the density of the upper forest trees Camellia japonica L. occurred in lower saplings do not have growth. The width of crown diameter class caused a narrow oppressed tree, the average tree height in the 8.09m, camellia in common was lower than that of tree height, variation diameter class in the width of crown distribution severe low correlations were analyzed. Third, the natural monument Camellia japonica L. forest soil composition, properties of soil pH, etc. 10 entries were analyzed components of the soil. In summary analysis properties of soil, soil pH, calcium, organic matter, magnesium was good and potassium content was insufficient, nitrogen and phosphorus were excess. Fourth, the growth condition of Camellia japonica L. forest and soil physicochemical properties, the results of the correlation analysis. magnesium, calcium, nitrogen affects the growth of Camellia japonica L. forest. Other seven kinds of items showed no effect on growth. Current Status and Future Growth of Camellia japonica L. forest soil and soil environments as well as the relationship between, Camellia Forest Factors affecting the growth of the state in terms of long-term ecological research and conservation status of settled Camellia japonica L. forest research for building materials there will be continued.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.469-478
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• 2019

Purpose: In this studies we examine the facilities damage characteristics caused by forest fire. Therefore, we surveyed damaged facilities from forest fire which was occurred on Goseong-Gun on march 28 in 2019.(damaged areas was 40ha) The types of facilities uses were house, public facility, warehouse and so on. 17 facilities were destroyed. The purpose of this study was to for establishing a disaster safety village in rural areas where damage from a similar type of disaster occurs repeatedly by conducting the consciousness survey targeting at experts and disaster safety officials in a local government. Method: We surveyed meteorological factors(temperature, wind speed, wind direction, humidity) per a minute for analyzing weather condition on Goseong-Gun when forest fire was occurred, spread and extinguished. And we surveyed forest fire risk factors(a slope degree, a slope direction, a geographical feature, a distance between forest and facility, main species, the existence of crown fire ignition, the direction of facility, the main material of building) around 10 damaged facilities. Finally, we analyzed damage pattern of facilities using meteorological factor and forest fire reisk fator Result: The weather condition of Kanseonng AWS (No.517) was high temperature, arid and strong wind, when the forest fire was occurred and spread. An average wind speed was 4.1m/s and the maximum wind speed was 11.6m/s. The main direction of wind was W(225~315°). Damaged facilities were located on the steep slope area and on the mountaintop. The forest density around facilities was high and main species was korean red pine. The crown fire was occurred in the forest around damaged facilities. The average distance was 13.5m from forest to facilities. When the main matarial of building was made by fire resistance materials (for example, rainforced concrete), the damage was slightly. on the other hand, when by flammable material (for example, a Sandwich Panel), the facilities were totally destroyed Conclusion: The results of this research which were the thinning around house, making a safety distance, the improvement of main material of building and etc, will be helpful for establishing a counter measure for a forest fire prevention of facilities in wild land urban interface