• Korean Journal of Environment and Ecology
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• v.12 no.1
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• pp.78-90
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• 1998

An objective of this study was to provide database for the planting disign of buffer green space. Types, planting structure, and effect of vuffer green space were investigated in five housing complexes of newtown of metropolitan area, Korea. Buffer green space in the study sites were constructed as mounding, slope, and plate. The number of species was found 20 tree and sub-tree species(10 evergreen and 20 deciduous species ) and 13 shrub species. These species were planted in one-storyed planting structure and there was no difference with ornamental species in the urban parks. Effect of sound proof by the buffer green space was recognized but sound level in four types among the seven types was observed above standard sound level for housing complex(65dB). Effect of sound proof was especially most effective in the mounding type. It was found that planting density and index of plant crown volume were mot satisfied to the function of buffer green space because of lower density and crown volume than natural vegetation per unit. Based on these results, this study suggested that buffer green space is desirable to be developed in the mounding type over two meters height with multi-layer planting model. In addition, there is needed to consider vegetation structure of natural forest around the developing site.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.439-447
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• 2019

The distance between the natural teeth and the implants is an important factor in preserving the periodontal tissues and esthetics. And abnormal positional displacement and tilting of the teeth during restorative procedure may require intentional root canal treatment and may affect masticatory function. This report is to present a successful full mouth rehabilitation of a patient with uneven dentition and collapsed occlusion using orthodontic and implant treatment. The patient had no symptoms or discomfort of temporomandibular joint disorder such as pain or sound. The orthodontic treatment was continued until implant provisional prosthesis delivery. And the vertical height of occlusion was elevated 2mm on anterior basis for anterior teeth protection and esthetics. After the orthodontic treatment, the implant abutments and natural teeth were finally restored with porcelain-fused-to-metal crowns and bridges. Satisfactory function and esthetic outcomes are observed after 6months of follow up.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.1
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• pp.36-43
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• 2012

Purpose: To analyze the stress distribution of the implant and its supporting structures through 3D finite elements analysis for implants with different hexagon heights and to make the assessment of the mechanical stability and the effect of the elements. Materials and methods: Infinite elements modeling with CAD data was designed. The modeling was done as follows; an external connection type ${\phi}4.0mm{\times}11.5mm$ Osstem$^{(R)}$ USII (Osstem Co., Pusan, Korea) implant system was used, the implant was planted in the mandibular first molar region with appropriate prosthetic restoration, the hexagon (implant fixture's external connection) height of 0.0, 0.7, 1.2, and 1.5 mm were applied. ABAQUS 6.4 (ABAQUS, Inc., Providence, USA) was used to calculate the stress value. The force distribution via color distribution on each experimental group's implant fixture and titanium screw was studied based on the equivalent stress (von Mises stress). The maximum stress level of each element (crown, implant screw, implant fixture, cortical bone and cancellous bone) was compared. Results: The hexagonal height of the implant with external connection had an influence on the stress distribution of the fixture, screw and upper prosthesis and the surrounding supporting bone. As the hexagon height increased, the stress was well distributed and there was a decrease in the maximum stress value. If the height of the hexagon reached over 1.2mm, there was no significant influence on the stress distribution. Conclusion: For implants with external connections, a hexagon is vital for stress distribution. As the height of the hexagon increased, the more effective stress distribution was observed.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.1
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• pp.41-50
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• 2020

The National Geographic Information Institute of Korea takes digital aerial photograph images every two years to make and modify/renew the digital map. The cameras for aerial photogrammetry to capture these digital aerial photographs are divided into frame types and line types. Computer vision analysis of aerial photograph images was only possible for frame type. Thus, in this study, Line type aerial photograph images was intended to generate geospatial information through computer vision analysis, and forest geospatial information was created as a method for the utilization of aerial picture images. As a result, geospatial information generated by computer vision analysis of line type aerial photograph images showed that RMSE of horizontal and vertical position errors was less than quadruple that of GSD. Forest geospatial information was generated using geospatial information generated by computer vision analysis. It was confirmed that extraction of the crown of tree and calculation of tree height are possible. Through this study, it is expected that utilization of aerial photograph images will be improved.

• Journal of Korean Dental Science
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• v.12 no.2
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• pp.48-57
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• 2019

Purpose: To investigate whether there are specific surgical or clinical conditions where the use of autogenous bone (AB) is superior to the use of bone substitutes (BSs) for maxillary sinus floor augmentation (MSFA). Materials and Methods: We retrospectively analyzed 386 implants after MSFA in 178 patients. The implants were divided into five groups according to the sinus graft material used. Risk factors for implant failure in MSFA, and correlation between residual bone height (RBH) and graft materials in terms of implant survival were investigated. To investigate risk factors for implant failure in MSFA, implant survival according to graft materials, patients' sex/age, surgical site, RBH, healing period prior to prosthetic loading, staged- or simultaneous implantation with MSFA, the crown-to-implant ratio, prosthetic type, implant diameter, and opposite dentition were evaluated. Result: The cumulative 2- and 5-year survival rates of implants placed in the grafted sinus (independent of the graft material used) were 98.7% and 97.3%, respectively. None of the investigated variables were identified as significant risk factors for implant failure. There was also no statistical significance in implant survival between graft materials. Conclusion: There were no specific surgical conditions in which AB was superior to BSs in terms of implant survival after MSFA.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.1
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• pp.58-65
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• 1999

The purpose of this study was to evaluate the effect of rehabilitation measures on the fired woodland of Chesuk-bong in Mt. Chiri through the vegetation structure and comparison of growth pattern between natural seedlings and transplanted Abies koreana seedlings. It was also discussed the rate of standing and fallen trees of dead conifers in the management strategy for vegetation regeneration and protection of sub-alpine area. In this fired woodland, shrub layers consisting of Weigela subsessilis, Sambucus williamsii var. coreana, Rhododendron schlippenbachii, R. mucronulatum, Tripterygium regelii, and etc. were gradually expanded, and tree species such as Betula ermani, Sorbus commixta, Acer pseudosieboldianum, and Malus baccata var. mandshurica were also regenerated. The growth of height and crown width of Abies koreana seedlings transplanted for vegetation regeneration were a little lower than those of natural seedlings. The seedlings of A. koreana transplanted in this fired woodland grew about 50.6% normally, but the others had multi-branched or growth stopped by death of terminal shoot. Because the number of dead conifers by fire tend to be gradually increased as time passed, it can occurs to the soil erosion and landslide by weakness of the cohesion and resistance of soil. Therefore, it is consider that rehabilitation measures projects of the fired woodland in subalpine area may be more prevention a natural disaster like soil erosion, flood and landslide.

• Journal of Environmental Science International
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• v.24 no.1
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• pp.55-64
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• 2015

The dry weight of mother plants' leaves had the highest increase rate in both NS (single-use) and NS+EM (mixed-use) mixed with NS 0.8 (customary use). In seafood amino acid fertilizer (SAF) application, the increase rate was highest in SAF solution at a 300-fold dilution. Mother plants' crown diameter, plant height, leaf length, leaf width, petiole length and leaf number showed the greatest growth amount when NS 0.8 (customary use) was mixed to NS (single-use) or NS+EM (mixed-use) solution. The growth was highest in SAF solution diluted 300 folds, but lowest in SAF solution diluted 100 folds. Of all inorganic nutrients, excluding sulfur, total amount of nitrogen, available phosphorus, potassium, calcium and magnesium had the highest increase rate in both NS (single-use) and NS+EM (mixed-use) with the treatment of NS 0.8 (customary use). Total nitrogen, in particular, was increased by 3.1% in NS 0.4, 6.0% in NS 0.8, and 4.5% in NS 0.8 with the application of NS+EM at a 500-fold dilution compared to NS alone. Total nitrogen amount showed the highest increase rate in SAF solution diluted 300 folds. Total nitrogen, available phosphorus, calcium, magnesium and EC in soils applied with culture solutions (NS, NS+EM) had increasing tendencies after fertilizer application. The results were comparable to those of SAF treatment. The increase rate of each inorganic nutrient composition declined in soils applied with NS+EM solution diluted 500 folds compared to NS alone.

• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.848-855
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• 2020

Land subsidence induced by underground coal mining leads to severe ecological and environmental problems. Arbuscular mycorrhizal fungi (AMF) have the potential to improve plant growth and soil properties. We aimed to assess the effects of AMF on the growth and soil properties of sea buckthorn under field conditions at different reclamation times. Inoculation with AMF significantly promoted the survival rate of sea buckthorn over a 50-month period, while also increasing plant height after 14, 26, and 50 months. Crown width after 14 months and ground diameter after 50 months of inoculation treatment were significantly higher than in the uninoculated treatment. AMF inoculation significantly improved plant mycorrhizal colonization rate and promoted an increase in mycelial density in the rhizosphere soil. The pH and electrical conductivity of rhizosphere soil also increased after inoculation. Moreover, after 26 and 50 months the soil organic matter in the inoculation treatment was significantly higher than in the control. The number of inoculated soil rhizosphere microorganisms, as well as acid phosphatase activity, also increased. AMF inoculation may play an active role in promoting plant growth and improving soil quality in the long term and is conducive to the rapid ecological restoration of damaged mining areas.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.667-694
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• 2015

The suspended dome system is a new structural form that has become popular in the construction of long-span roof structures. Suspended dome is a kind of new pre-stressed space grid structure that has complex mechanical characteristics. In this paper, an optimum topology design algorithm is performed using the enhanced colliding bodies optimization (ECBO) method. The length of the strut, the cable initial strain, the cross-sectional area of the cables and the cross-sectional size of steel elements are adopted as design variables and the minimum volume of each dome is taken as the objective function. The topology optimization on lamella dome is performed by considering the type of the joint connections to determine the optimum number of rings, the optimum number of joints in each ring, the optimum height of crown and tubular sections of these domes. A simple procedure is provided to determine the configuration of the dome. This procedure includes calculating the joint coordinates and steel elements and cables constructions. The design constraints are implemented according to the provision of LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Constitution). This paper explores the efficiency of lamella dome with pin-joint and rigid-joint connections and compares them to investigate the performance of these domes under wind (according to the ASCE 7-05), dead and snow loading conditions. Then, a suspended dome with pin-joint single-layer reticulated shell and a suspended dome with rigid-joint single-layer reticulated shell are discussed. Optimization is performed via ECBO algorithm to demonstrate the effectiveness and robustness of the ECBO in creating optimal design for suspended domes.

• The korean journal of orthodontics
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• v.47 no.2
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• pp.77-86
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• 2017

Objective: The aim of this study was to evaluate the skeletal and dentoalveolar changes after miniscrew-assisted rapid palatal expansion (MARPE) in young adults by cone-beam computed tomography (CBCT). Methods: This retrospective study included 14 patients (mean age, 20.1 years; range, 16-26 years) with maxillary transverse deficiency treated with MARPE. Skeletal and dentoalveolar changes were evaluated using CBCT images acquired before and after expansion. Statistical analyses were performed using paired t-test or Wilcoxon signed-rank test according to normality of the data. Results: The midpalatal suture was separated, and the maxilla exhibited statistically significant lateral movement (p < 0.05) after MARPE. Some of the landmarks had shifted forwards or upwards by a clinically irrelevant distance of less than 1 mm. The amount of expansion decreased in the superior direction, with values of 5.5, 3.2, 2.0, and 0.8 mm at the crown, cementoenamel junction, maxillary basal bone, and zygomatic arch levels, respectively (p < 0.05). The buccal bone thickness and height of the alveolar crest had decreased by 0.6-1.1 mm and 1.7-2.2 mm, respectively, with the premolars and molars exhibiting buccal tipping of $1.1^{\circ}-2.9^{\circ}$. Conclusions: Our results indicate that MARPE is an effective method for the correction of maxillary transverse deficiency without surgery in young adults.