• 제목/요약/키워드: Water way

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Evaluation of shear-bond strength between different self-adhesive resin cements with phosphate monomer and zirconia ceramic before and after thermocycling (인산염계 기능성 단량체가 첨가된 수종의 자가 접착 레진시멘트와 지르코니아 세라믹 사이 열순환 전후 전단결합강도 비교)

  • Lee, Ji-Hun;Kim, Min-Kyung;Lee, Jung-Jin;Ahn, Seung-Geun;Park, Ju-Mi;Seo, Jae-Min
    • The Journal of Korean Academy of Prosthodontics
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    • v.53 no.4
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    • pp.318-324
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    • 2015
  • Purpose: This study compared shear bond strengths of five self-adhesive cements with phosphate monomer to zirconium oxide ceramic with and without airborn particle abrasion. Materials and methods: One hundred zirconia samples were air-abraded ($50{\mu}mAl_2O_3$). One hundred composite resin cylinders were fabricated. Composite cylinders were bonded to the zirconia samples with either Permacem 2.0 (P), $Clearfil^{TM}$ SA Luting (C), $Multilink^{(R)}$ Speed (M), $RelyX^{TM}$ U200 Automix (R), G-Cem $LinkAce^{TM}$ (G). All bonded specimens were stored in distilled water ($37^{\circ}C$) for 24 h and half of them were additionally aged by thermocycling ($5^{\circ}C$, $55^{\circ}C$, 5,000 times). The bonded specimens were loaded in shear force until fracture (1 mm/min) by using Universal Testing Machine (Model 4201, Instron Co, Canton, MA, USA). The failure sites were inspected under field-emission scanning electron microscopy. The data was analyzed with ANOVA, Tukey HSD post-hoc test and paired samples t-test ($\alpha$=.05). Results: Before and after thermocycling, $Multilink^{(R)}$ Speed (M) revealed higher shear-bond strength than the other cements. G-Cem $LinkAce^{TM}$ (G) showed significantly lower bond strengths after thermocycling than before treatment (P<.05), but the other groups were not significantly different (P>.05). Conclusion: Most self-adhesive cements with phosphate monomer showed high shear bond strength with zirconia ceramic and weren't influenced by thermocycling, so they seem to valuable to zirconia ceramic bonding.

A STUDY ON WEAR RESISTANCE OF FLOWABLE COMPOSITE RESINS (유동성 복합레진의 마모저항성에 관한 연구)

  • Yun, Yeon-Hee;Kim, Jung-Wook;Lee, Sang-Hoon;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.29 no.2
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    • pp.217-225
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    • 2002
  • When we use the flowable resin on the primary molars for quick handling, one of the most important property is the wear resistance. This study was performed to compare the wear resistance characteristics of four flowable composite resins [Arabesk flow (group 1), Tetric flow (group 2), Aeliteflow (group 3), Filtek flow (group 4)] to that of one control composite resin [Z100 (group 5)]. Specimen discs(n=10), 10mm wide and 2mm thick, were stored in distilled water at $37^{\circ}C$ for 7 days prior to testing. The specimens were subjected to 50,000 strokes at 2 Hz on the MTS system. During the test, the following parameters were maintained: the lateral excursion at 0.4mm, occlusal force at 2-100N with a force profile in the form of a half sine wave. The measurements of volume loss, depth of wear, and Vicker's hardness number of composite resins, and SEM observations of the polished and abraded surfaces were established. One-way ANOVA and Scheffe's multiple comparison test were employed to detect statistically significant differences among the flowable composite resin groups and the control composite group at P<.05. The following results were obtained: 1. Group 3 showed the least volume loss, while group 4 showed the greatest. The mean volume loss increased in the following order: group 3

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A Study on the Representation Characteristics of Yuanming New Garden in China by Traditional Landscape Creation Techniques (전통조경 조성 기법으로 본 중국 원명신원의 재현 특성 고찰)

  • Kim, Dong-Hyun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.38 no.1
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    • pp.103-114
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    • 2020
  • This study was conducted on Yuanming New Garden in China, which re-lighted the previously lost or damaged original space through representation from the perspective of creating traditional landscape. We looked at the composition of this place, the comparison of relevant literature and actual representation, and the characteristics of representation techniques. The results are as follows. First, TYuanming New Garden is a representation space with the motif of Yunamingyuan in Beijing. An advisory group of some 400 related experts discussed the prototype. The historicity of the real space was considered in the representation process. Second, New Yuanmingyuan garden was recreated based on the 'The Forty Scenic Views of Yuanmingyuan', and 31 of the scenic spots were created. The buildings in each precinct had a 1:1 scale response with structures that were previously constructed in Yuanmingyuan, Beijing. New Yuanmingyuan garden's way in which the main landscape is laid out around the Fuhai Lake(福海), which the landscape is drawn appeared was the same as Yuanmingyuan in Beijing. However, some of the facilities were reproduced on the basis of the 'The Forty Scenic Views of Yuanmingyuan', so they turned out to be different from what Yuanminyuan in Beijing looks like today. New Changchunyuan garden was represented around water landscape of the Western Mansins(Xiyang Lou, 西洋樓) area and the Haeakgaegum(海岳開襟), and the buildings and the facilities were reconstructed based on the 'Copper Print of Western Mansins'. Third, Yuanming New Garden made a prototype of the 'The Forty Scenic Views of Yuanmingyuan' and 'Copper Print of Western Mansins' during the process of synchronic changes in the garden. In addition, the original space and the ambiguous original space or exhibition space were clearly identified through the plant. On the other hand, due to the reenactment of buildings, the spatial composition and placeability of the original spaces of Yuanmingyuan garden and Changchunyuan garden in Beijing were not inherited, and the introduction of elements that did not match traditional landscaping spaces, and the introduction of garden elements that were not prototype and other variations for the use of tourism were found to be drawback.

Study on the Rice Yield Reduction and Over head Flooding Depth for Design of Drainage System (배수 설계를 위한 벼의 관수심 및 관수피해율에 관한 연구)

  • 김천환;김시원
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.24 no.4
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    • pp.69-79
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    • 1982
  • The objective of this study is to contribute to drainage planning in the most realistic and economical way by establishing the relationship between rice yield reduction and overhead flooding by muddy water of each growth stage of paddy, which is the most important factor in determining optimum drainage facilities. This study was based on the data mainly from the experimental reports of the Office of Rural Development of Korea, Reduction Rate Estimation for Summer Crops, published by Ministry of Agriculture and Forestry of Japan and other related research documenta- tion. The results of this study are summarized as follows 1. Damages by overhead flooding are highest in heading stage and have the tendency of decrease in the order of booting stage, panicle formation stage, tillering stage, and stage just after transplanting. Damages by overhead flooding of each growing stage are as follows: a) It is considered that overhead flooding just after transplanting gives a little influence on plant growth and yield because the paddy has sufficient growth period from floo ding to harvest time. b) Jt is analyzed that according to the equation y=11 12x 0.908 which is derived from this study, damages by overhead flooding during tillering stage for 1, 2, 3 successive days are 11.1 %, 20.9%, and 30.2% respectively. c) Damages by overhead flooding after panicle formation stage are very serious because recovering period is very short after damage and ineffective tillering is much. Acc- ording to the equation y=9. 58x+10. Ol derived from this study, damages by overhead flooding fal 1,2,3,5 successive days are 19.6%, 29.2%, 38.8%, 57.9% respectively. d) Booting stage is the very important period in which young panicle has grown up almost completely and the number of glumous flower is fixed since reduction division takes place in the microspore mother cell and enbryo mother cell. According to the equation y=39. 66x 0.558 derived from this study, damages by overhead floodingfor 0.5, 1, 3, 5 successive days are 26.9%, 39.7%, 72. 2% and 97.4%, respectively. Therefore, damages by overhead flooding is very serious during the hooting stage. e) When ear of paddy emerges, flowering begins on that day or the next day; when paddy flowers, fertilization will be completed 2-3 hours after flowering. Therefore overhead flooding during heading stage impedes flowering and increases sterilizing percentage. From this reason damages of heading stage are larger than that of booting stage. According to the equation y-41 94x 0.589 derived from this study, damages by overhead flooding for 0.5, 1, 3, 5, successive days are 27.9%, 63.1 %, 80.1%, and 100% 2. Considering that temperature of booting stage is higher than that of beading stage and plant height of booting stage is ten centimeters shorter than that of heading stage, booting stage should be taken as a critical period for drainage planning because possi- bility of damage occurrence in booting stage is larger than that of heading stage. There-fore, it is considered that booting stage should be taken as critical period of paddy growth for drainage planning. 3. Overhead flooding depth is different depending on the stage of growth. In case, booting stage is adopted as design stage of growth for drainage planning, it is conside red that the allowable flooding depth for new varieties and general varieties are 70cm and 80cm respectively. 4. Reduction Rate Estimation by Wind and Flood for Rice Planting of the present design criteria for drainage planning shows damage by overhead flooding for 1 to 2, 3 to 4, 5 to 7 consecutive days; damages by overhead flooding varies considerably over several hours and experimental condition of soil, variety of paddy, and climate differs with real situation. From these reasons, damage by flooding could not be estimated properly in the past. This study has derived the equation which shows damages by flooding of each growth stage on an hourly basis. Therefore, it has become possible to compute the exact damages in case duration of overhead flooding is known.

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Avifauna and Management of Breeding Season in Taeanhaean National Park (태안해안국립공원의 번식기 조류상과 관리)

  • Paik, In-Hwan;Jin, Seon-Deok;Yu, Jae-Pyoung;Paek, Woon-Kee
    • Korean Journal of Environment and Ecology
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    • v.24 no.2
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    • pp.139-146
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    • 2010
  • The survey was done in order to find what kinds of birds visit Taeanhaean National Park during breeding season, where we fixed up 10 coastal areas and islands within the National Park. Three groups concurrently performed the field research from 5th to 9th of July in 2009. Total 58 species and 7,323 individuals were recorded in Taeanhaean National Park. 48 species including 6,187 individuals were observed in coastal areas and 33 species including 1,136 individuals in island areas. The most dominant species in the National Park are Larus crassirostris which accounts for 60% of the birds inhabiting there, and they seem to have been bred in the islands near the National Park. The birds observed only around the coastal areas include Anas poecilorhyncha, Fulica atra, Egretta intermedia and the others which consist of 25 species and amount to 318 individuals, and the birds found exclusively in island areas include Phalacrocorax filamentosus, Apus pacificus¸ Locustella pleskei and other birds, which consist of 10 species and the number of those individuals observed was 308. The inhabited islands areas such as Gauido were characterized by high ratio of waterbird population, which seems to be correlated with the factors such as the extent of island, the richness of water resources, and the diversity of habitats. Based on the data collected during the research and other data from the previous observations, the kinds of dominant species remain nearly unchanged. And in spite of the oil spill accident in 2007, the increase in the number of waterbirds compared to 2004 may be the evidence that the area is recovering from the environmental pollution. At present, the tidal power plants are being built or scheduled to be built and large-scale reclamation is also under way. What is worse, those areas are seeing the increase of pension construction, which is likely to be the potential cause of damage and disturbance against some key habitats for the waterbirds. Therefore, it is a major priority that we build the bird information system to efficiently manage the knowledge-based asset collected from bird-watching groups and to better monitor the areas that need enhanced database through which the National Park can be appropriately administered.

Effects of a 12-week, school-based obesity management program on obese primary school children (12주간의 학교 비만 관리 프로그램이 초등학교 비만 아동에 미치는 효과)

  • Kim, Han Gyu;Lim, Goh-woon;Kim, Hae Soon;Hong, Young Mi
    • Clinical and Experimental Pediatrics
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    • v.53 no.3
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    • pp.335-340
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    • 2010
  • Purpose : This study was designed to determine the effects of a school-based obesity-management program on obese primary school children. Methods : A total of 995 children (6-2 years old) in a primary school were screened in March 2008, and of those, 101 obese students (44 boys and 57 girls, body mass index (BMI) ${\geq}95$ percentile) were enrolled for a study group. The schoo-lbased, obesity management program, which includes physical exercise and nutritional education, was conducted as part of an extracurricular program for 12 weeks. The measurement of height, weight, waist circumference, blood pressure (BP), and bioelectrical impedance analysis (BIA) was performed before and after the program.Results : Height and weight increased significantly (P <0.05). The BMI and obesity index decreased significantly (P <0.01). Systolic and diastolic BP decreased significantly (P <0.01). BMI decreased in 61.4% of boys and 66.7% of girls. Protein and basal metabolic rate (BMR) increased significantly on the BIA (P <0.01). Fat decreased significantly (P <0.05). The total body water (TBW) and percent body fat (PBF) decreased significantly (P <0.01). The changes in protein, fat, TBW, PBF, and BMR significantly correlated to the change in BMI (P <0.05). In a multiple logistic regression analysis, BMI change was significantly correlated to the changes in protein and fat content (P <0.01). Conclusion : The school-based obesity management program is a very effective way to manage obesity for obese primary school children.

Escape from Binary Opposition -Analysis of Performative Method in - (이항대립(二項對立)으로부터의 탈주 -<오목어>에서의 매체 수행 방식 분석-)

  • Suh, Yong-Chu
    • Cartoon and Animation Studies
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    • s.41
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    • pp.511-531
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    • 2015
  • The underlying impetus of the birth of animated film is attraction about a moving image. And the animation image occurs from the process of performative relationship between an animator and apparatus. Therefore, analysing the method how the moving image is constructed will be the focal starting point to deal with an animated film as a text. In this context, that conveys the theme in more sensuous way will be examined in a dimension of the material, technique and image-making method. KIM Jin-man's is a Stop Motion Animated Film with Noodlescreen about a journey of a fish that wishes to go outside of the water. KIM created original and friendly images out of plain thin noodle which is a common ingredient in Korea, and dealt with the ontological introspection based of the concept of Nondualism. Nondualism based on the interconnected and cyclical eastern philosophy which is different from the western dualistic theory points to the idea that the universe and all its multiplicity are ultimately expressions or appearances of one essential reality. This paper focuses on KIM's recent work and sees how Nondualism is applied throughout the animated film by analysing the performative method of mediums, technique, and structure. First of all, the form of Noodlescreen will be reviewed in Chapter Two. Pinscreen Animation which was invented by Alexander Alexeieff and Claire Parker will be also compared with Noodlescreen in the aesthetic viewpoint here. In Chapter Three, it will be analysed how the description of the image of binary opposition itself provides expanded sense and rich metaphor. Lastly, the format of Mise-en-abyme going constantly towards outer space will be dealt how it exposes the cinematic illusion and spatiality in Chapter Four. Throughout the whole chapters, it will reviewed how the concept of Nondualism relates the images of and deactivate the boundary of binary opposition in terms of both the story development and the visualization method. By this methodology, it will be confirmed that image of animated film not only explains the narrative but also activates the perception about the theme and provides integrated sensory experiences in the independent and expanded dimension.

MICROLEAKAGE AND SHEAR BOND STRENGTH OF FLOWABLE COMPOSITE RESIN (Flowable Composite Resin의 미세변연누출 및 전단결합강도)

  • 박성준;오명환;김오영;이광원;엄정문;권혁춘;손호현
    • Restorative Dentistry and Endodontics
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    • v.26 no.4
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    • pp.332-340
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    • 2001
  • Flowable composite resin has lower filler content, increased flow, and lower modules of elasticity. It is suggested that flowable composite resin can be bonded to the tooth structure intimately and absorb or dissipate the stress. Therefore, it may be advantageous to use flowable composite resin for the base material of class II restoration and for the class V restoraton. The purpose of this study was to evaluate the microleakage and shear bond strength of four flowable composite resins (Aeliteflo, Flow-It, Revolution, Ultraseal XT Plus) compared to Z100 using Scotchbond Multi Purpose dentin bonding system. To evaluate the microleakage, notch-shaped class V cavities were prepared on buccal and lingual surfaces of 80 extracted human premolars and molars on cementum margin. The teeth were randomly divided into non-thermocycling group (group 1) and thermocycling group (group 2) of 40 teeth each. The experimental teeth of each group were randomly divided onto five subgroups of eight samples (sixteen surfaces). The Scotchbond Multi-Purpose and composite resin were applied for each group following the manufacturer's instructions. the teeth of group 2 were thermocycled five hundred times between 5$^{\circ}C$ and 55$^{\circ}C$. The teeth of group 2 were placed in 2% methylene blue dye for 24 hours, then rinsed with tab water. The specimens were embedded in clear resin, and sectioned longitudinally with a diamond saw. The dye penetration on each of the specimen were observed with a stereomicioscope at $\times$20 magnification. To evaluate the shear bond strength, 60 teeth were divided into five groups of twelve teeth each. The experimental teeth were ground horizontally below the dentinoenamel junction, so that no enamel remained. After applying Scotchbond Multi-Purpose on the dentin surface, composite resin was applied in the shape of cylinder. The cylinder was 4mm in diameter and 2mm in thickness. Shear bond strength was measured using Instron with a cross-head speed of 0.5mm/min. After shear bond strength measurement, mode of failure was evaluated with a stereomicroscope at $\times$30 magnification. All data were statistically analyzed by One Way ANOVA and Student-Newman-Keuls method. The correlation between microleakage and shear bond strength was analyzed by linear regression. The results of this study were as follows ; 1. In non-thermocycling group, the leakage value of Z100 was significantly lower than those of flowable composite resins at the enamel and dentin margin, margin, except that Revolution showed the lower leakage value than that of Z100 at the dentin margin (p<0.05). 2. In thermocycling group, the leakage values of Z100 and Ultraseal XT Plus were lower than those of other subgroup at the enamel and dentin margin, except that Flow-It showed the lower leakage value than that of Ultraseal XT Plus at the dentin margin (p<0.05). 3. The leakage value of Z100 and Ultraseal XT Plus in thermocycling group were not higher than that in non-thermocycling group at the enamel margin. The leakage value of Z100 in thermocycling group was not higher than that in non-thermocycling group at the dentin margin (p<0.05). 4. As for the shear bond strength measurement, there were no statistically significant differences among groups (p<0.05). The shear bond strengths given in descending order were as follows: Z100(16.81$\pm$2.98 MPa), Flow-It(14.8$\pm$4.43 MPa), Aeliteflo(14.34$\pm$3.69 MPa), Revolution(13.46$\pm$4.23 MPa), Ultraseal XT Plus(12.83$\pm$3.16 MPa). 5. Failure modes of all specimens were adhesive failures. 6. There was no correlation between microleakage and shear bond strength.

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SHEAR BOND STRENGTH AND MICROLEAKAGE OF COMPOSITE RESIN ACCORDING TO TREATMENT METHODS OF CONTAMINATED SURFACE AFTER APPLYING A BONDING AGENT (접착제 도포후 오염된 표면의 처리방법에 따른 복합레진의 전단결합강도와 미세누출)

  • Park, Joo-Sik;Lee, Suck-Jong;Moon, Joo-Hoon;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.24 no.4
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    • pp.647-656
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    • 1999
  • The purpose of this study was to investigate the shear bond strength and marginal microleakage of composite to enamel and dentin according to different treatment methods when the applied bonding agent was contaminated by artificial saliva. For the shear bond strength test, the buccal and occlusal surfaces of one hundred twenty molar teeth were ground to expose enamel(n=60) and dentin surfaces(n=60). The specimens were randomly assigned into control and 5 experimental groups with 10 samples in each group. In control group, a bonding system(Scotchbond$^{TM}$ Multi-Purpose plus) and a composite resin(Z-100$^{TM}$) was bonded on the specimens according to manufacture's directions. Experimental groups were subdivided into 5 groups. After polymerization of an adhesive, they were contaminated with at artificial saliva on enamel and dentin surfaces: Experimental group 1 ; artificial saliva was dried with compressed air. Experimental group 2 ; artificial saliva was rinsed with air-water spray and dried. Experimental group 3 ; artificial saliva was rinsed, dried and applied an adhesive. Experimental group 4 ; artificial saliva was rinsed, dried, and then etched using phosphoric acid followed by an adhesive. Experimental group 5, artificial saliva was rinsed, dried, and then etched with phosphoric acid followed by consecutive application of both a primer and an adhesive. Composite resin(Z-100$^{TM}$) was bonded on saliva-treated enamel and dentin surfaces. The shear bond strengths were measured by universal testing machine(AGS-1000 4D, Shimaduzu Co. Japan) with a crosshead speed of 5mm/minute under 50kg load cell. Failure modes of fracture sites were examined under stereomicroscope. The data were analyzed by one-way ANOVA and Tukey's test. For the marginal microleakage test, Class V cavities were prepared on the buccal surfaces of sixty molars. The specimens were divided into control and experimental groups. Cavities in experimental group were contaminated with artificial saliva and those surfaces in each experimental groups received the same treatments as for the shear test. Cavities were filled with Z-100. Specimens were immersed in 0.5% basic fuchsin dye for 24 hours and embedded in transparent acrylic resin and sectioned buccolingually with diamond wheel saw. Four sections were obtained from the one specimen. Marginal microleakages of enamel and dentin were scored under streomicroscope and averaged from four sections. The data were analyzed by Kruskal-Wallis test and Fisher's LSD. The results of this study were as follows. 1. The shear bond strength to enamel showed lower value in experimental group 1(13.20${\pm}$2.94MPa) and experimental group 2(13.20${\pm}$2.94MPa) than in control(20.03${\pm}$4.47MPa), experimental group 4(20.96${\pm}$4.25MPa) and experimental group 5(21.25${\pm}$4.48MPa) (p<0.05). 2. The shear bond strength to dentin showed lower value in experimental group 1(9.35${\pm}$4.11MPa) and experimental group 2(9.83${\pm}$4.11MPa) than in control group(17.86${\pm}$4.03MPa), experimental group 4(15.04${\pm}$3.22MPa) and experimental group 5(14.33${\pm}$3.00MPa) (p<0.05). 3. Both on enamel and dentin surfaces, experimental group 1 and 2 showed many adhesive failures, but control and experimental group 3, 4 and 5 showed mixed and cohesive failures. 4. Enamel marginal microleakage was the highest in experimental group 1 and there was a significant difference in comparison with other groups (p<0.05). 5. Dentin marginal microleakages of experimental group 1 and 2 were higher than those of other groups (p<0.05). This result suggests that treatment methods, re-etching with 35% phosphoric acid followed by re-application of adhesive or repeating all adhesive procedures, will produce good effect on both shear bond strength and microleakage of composite to enamel and dentin if the polymerized bonding agent was contaminated by saliva.

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A Study on Proposal of Landscape Management Improvement on the Quantitative Analysis of National Parks (국립공원(國立公園) 자연경관(自然景觀)의 계량적(計量的) 분석(分析)을 통(通)한 경관관리(景觀管理) 개선방안(改善方案)에 관(關)한 연구)

  • Kim, Sei Cheon
    • Journal of Korean Society of Forest Science
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    • v.80 no.1
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    • pp.32-41
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    • 1991
  • This study is focusted to the national park of Korean typical mountain Chi-ri, its visual resources of forests, and practiced inspectind course by way of hypothesis and tests, to show visual resource management objectively, and that of quantitative basic data. spatial image structure measured by Semantic Differential(S.D.) Scale was shown through factor analysis algorithm for the analyzing psychological amount and examined the flowing out of decisive factor and the objective importance related mutual factors by appling the measurement of visual quality. Also, it has been investigated the differences between the degrees of expectation which is used before and of satisfaction which is used, by appling instrumental expectation theory. And showed patterns of investigation area through factor analyzing algorithm. As a national Park, visual factors that have natural landscape harmonized forest, sky, surface of the water, curious stones and rocks, temples should be escalate their values affirmatively so as to be the scenery of pointed direction and enjoyable, and it is needs the techniques visual resource management and its controlling technique to make artificial structures more intentional planning and systemical setting. Manmade distinctive quality in the spatials that affect complementally or harmonizingly, should be received considering relations between the distifution and joining which in line with various visual presenting massive factors. More than that, it is needed united basic standard to the beauty of arrangements which contain visual continuity considered balance between nature and human work, simplicity of structural types, assimilation, emphasis, unification of different factors and pro rata.

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