• Computers and Concrete
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• 제20권4호
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• pp.483-490
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• 2017

This paper studies on the behavior of reinforced concrete (RC) pipes used in basic sanitation in the conduction of storm water and sanitary sewer. Pipes with 800 mm and 1200 mm in diameter were analyzed. The 800 mm pipes were built with simple reinforcement and the 1200 mm pipes with double reinforcement. For the two diameters of pipes the presence or absence of the pocket was evaluated, and the denomination of each one is spigot and pocket pipe (SPP) and ogee joint pipe (OJP), respectively. The 3D numerical models reproduce the three-edge-bearing test that provides information about the strength and stiffness of the reinforced concrete pipes. The validation of the computational models was carried out comparing the vertical and horizontal displacements on the springline and crown/invert and it was also evaluated the reinforcement strains and the crack pattern. As a main conclusion, the numerical models represented satisfactorily the behavior of the pipes and can be used in future studies in parametric analysis.

• The Journal of Advanced Prosthodontics
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• 제9권1호
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• pp.1-13
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• 2017

PURPOSE. The purpose of this study was to compare the fit of cast gold crowns fabricated from the conventional and the digital impression technique. MATERIALS AND METHODS. Artificial tooth in a master model and abutment teeth in ten patients were restored with cast gold crowns fabricated from the digital and the conventional impression technique. The forty silicone replicas were cut in three sections; each section was evaluated in nine points. The measurement was carried out by using a measuring microscope and I-Soultion. Data from the silicone replica were analyzed and all tests were performed with ${\alpha}$-level of 0.05. RESULTS. 1. The average gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. 2. In marginal and internal axial gap of cast gold crowns, no statistical differences were found between the two impression techniques. 3. The internal occlusal gaps of cast gold crowns fabricated from the digital impression technique were larger than those of the conventional impression technique significantly. CONCLUSION. Both prostheses presented clinically acceptable results with comparing the fit. The prostheses fabricated from the digital impression technique showed more gaps, in respect of occlusal surface.

• 대한기계학회논문집A
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• 제24권4호
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• pp.907-915
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• 2000

The movement of teeth and initial stress associated with the treatment of orthodontics have been successfully studied using the finite element method. To reduce the effort in preprocessing of finite element analysis, we developed two types of three-dimensional finite element models based on the standard teeth model. Individual malocclusions were incorporated in the finite element The movement of teeth and initial stress associated with the treatment of orthodontics have been successfully studied using the finite element method. To reduce the effort in preprocessing of finite element analysis, we developed two types of three-dimensional finite element models based on the standard teeth model. Individual malocclusions were incorporated in the finite element models by considering the measuring factors such as angulation, crown inclination, rotation and translations. The finite element analysis for the wire activation with a T-loop arch wire was carried out. Mechanical behavior on the movement and the initial stress for the malocclusion finite element model was shown to agree with the objectives of the actual treatment. Finite element models and procedures of analysis developed in this study would be suitably utilized for the design of initial shape of the wire and determination of activation displacements.

• 한국농촌건축학회논문집
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• 제16권1호
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• pp.111-117
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• 2014

The aim of this study is to find out the pattern of Ger form, inner spatial composition of Mongolian Ger house, and to take a dig at the structural or symbolic elements of nomadic architecture of Ger. To the point of view of corresponding to living and space of housing, remarkable characteristics of Ger Architecture is able to pull down and recombine the structures of nomadic house. Even though urbanization of Mongolia has spreading rapidly in a whole nation, most of people preserves traditional housing pattern within Ger. The ways of survey are to study of traditional home of Mongolia, and then field work at residence or mountain area in Ulan Bator and Gorkhi Terelj National Park area. This survey contains the form, size, structure, spatial composition of living space, structure, and materials. There are three results as follows: First, the form of Ger house is like a pyramidal or crown roof style to approximate to the round shape of it. Usually they had lived in nomadic way of life, so the Ger had a movable and flexible structure. Second, the Ger is easy to build up and deconstruct to move or find a new pasture. Third, the Mongolian Ger structure is composed by mainly five elements that are Khana, Khaalga, Toono, Bagana, and Uni. It has a hierarchy of internal spaces which are classified to gender, orientation, and property.

• 한국가구학회지
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• 제11권1호
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• pp.13-23
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• 2000

This study was carried out to investigate the wood properties for development the proper uses of lesser-known tree species. The tested species are Kebambang(Pentace sp.), Bawang-bawang(Dysoxylum alliaceum Bl .), Garu buaya( Gonystylus brunescens A. Shaw)grown in Indonesia. fundamental wood properties such as anatomical, physical, mechanical and chemical properties and characteristics related to wood processing were examined. The results are summarized as follows : The woods of these species are diffuse porous, coarse textured, and interlocked grained. The heartwood of Kebambang is distinguished clearly to the sapwood, but the heartwood of other species are not distinguished clearly to the softwood. The woods of Kebambang and Bawang-bawang have the moderate weight density and the low strength properties, but Garu buaya has the high weight density and the high strength properties. The woods of these species has high shrinkage. The sawing characteristics of Kebambang are excellent but the other species are moderate. The machining characteristics by planer and drying characteristics of these species are moderate. These woods has poor characteristics in bending processing and decay durability. The wood of Bawang-bawang has high content of the extractives and lignin.

• 동력기계공학회지
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• 제7권4호
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• pp.12-18
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• 2003

Various measures have been tried to reduce the NOx emission from diesel engine, but with partial success because the mechanisms of NOx and PM formations appear to have trade-off relation between each other. Therefore it has been known to be difficult to reduce NOx emission and PM emission simultaneously. Two stage combustion method i,e. a combustion process which has rich combustion stage and lean combustion stage one by one, has been developed successfully to reduce NOx formation in the continuous combustion chambers such as in the boilers. But until yet it is not successful to apply the same method in intermittent combustion chamber like in the diesel engine cylinder, as it was, only several research works were carried out. In this study, devised was a uniquely shaped combustion chamber with reformed piston crown intended to keep fuel-rich condition during early stage of combustion and fuel-lean condition during next stage. It was found that the NOx emission decreased significantly at various conditions of operation with the two stage combustion type engines of PR20 type, but other values such as smoke, CO and specific fuel consumption deteriorated as usual.

• 한국환경생태학회지
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• 제11권1호
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• pp.37-45
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• 1997

지리산국립공원 노고단 지역에 분포하는 아고산대 초원지역은 급증한 이용객들에 의해 훼손되고 있다. 교란된 아고산대 초원지역의 복원공법을 개발하기 위한 기초연구로서, 이 지역에 시비처리, 식생도입처리, 멀칭처리를 각각 2수준으로 한 2*2*2 요인 실험을 표토가 유실된 10% 경사지와 표토가 잔존하는 40% 경사지에 실시하였다. 그 결과, 부지조건에 관계없이 야생풀포기심기가 파종보다 식생활착에 있어 더 효율적이었고 시비처리는 출현개체수와 피복도 증가에 통계적 유의성을 나타냈다. 반면 식생활착에 미치는 멀칭재료간 효과는 유의성이 없었다. 한편 척박지의 선구수종으로 추정되는 개쑥부쟁이는 직접파종에도 높은 활착율을 보였다.

• 대한치과교정학회지
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• 제4권1호
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• pp.57-61
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• 1974

The patient, a girl of 19 years in good health, had a class I malocclusion. The maxillary left centra1 incisors and both lateral incisors had already erupted. But the space for the right central incisor was partially closed by the mesial drifting of the neighboring teeth. The caused a shift in the midline and a cross-bite relation on the incisors. X-ray examination revealed the presence of the right central incisor in the alveolar bone and odontoma just above the crown of the right central incisor. After enough space for the impacted incisor was created in the dental arch with a open-coil spring the rectangular incision was made. Removing the odontoma uncovered the flat surface of the labial aspect of the incisor. During the tooth had erupted of its own accord, any unnecessary force had been imposed on the tooth. When it was decided that the tooth should be brought out by the mechanical device, the gold cast onlay with hook was used and run a light elastic between this hook and the main arch wire. Finally the tooth was brought down to the arch level. The result was excellent. Fortunately the esthetic problem and any detrimental effects on the psychological make-up could be avoided.

• 한국조경학회지
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• 제23권3호
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• pp.48-58
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• 1995

This study was conducted to investigate the plant community and to propose ecological planning methods for urban environmental forest on Gaepo neighborhood park, Gangnamgu in Seoul. Thirty-six plots that the size of each plot was 10$\times$10m(100\ulcorner) were set up and the vegetation analysis was carried out. Field survey was executed Apirl, 1994. The actual vegetation was consisted of Poplulus$\times$albaglandulosa community(73.03%), Robinia pseudoacacia community(8.30%) P. $\times$ albaglandulosa-R.pseudoacacia community(1.81%) and environmental forest (15.22%) in the survey site. According to mean importance values of each plot, survey area were divided into ten forest communities. As for the analysis of plant community structure which was classified into ten forest communities, the importance values, ecological diversity, number of species, number of individuals, basal area and crown coverage of urban environmental forest were relatively lower than those of the native community. In urban environmental forest of Gaepo neighborhood park, it showed problems for the planting method. So urban environmental forest should be constructed considering ecological characteristics based on above results.

• The Korean Journal of Ecology
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• 제8권2호
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• pp.109-117
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• 1985

This report is a part of the investigations of the secondary vegetation successions carried out and the analysis of soil properties in the burned areas of forest. The fires-crown fire and surface fire-were occurred at April, 1978 and February, 1984. The investigations were carrited out from August 10. 1983 to September 25, 1984. The burned areas studied are located in southern slope of Mt. Ssalibagu (above sea-level, 590m), So-myon, Sungju-gun, Chollanam-do, Korea. The results are as follows: The floristic compositions of the burned area at the 5th year after the fires were 85 families, 250 genera, 321 species and 53 varieties. Among them, 85 families, 127 genera, 129 species and 30 varieties were found in the currently burned area. In all the sampling sites (10*10cm), 31 and 57 species were found in the currently burned and in the 5th years after the fires, respectively. Miscanthus sinensis var. purpurascens, Quercus serrata and Festuca ovina were dominant species in the both areas. Biological spectra in both the burned areas showed $H-D_1-R_5-e$ type. Degree of the succession(DS) was 412-884 in the 5th years passed burned area and it was high level. Species diversity index(H) was 0.59~1.13 and evennes index(e) was 0.43~0.79, these indexes between both areas were different considerably. Indexes of similarity between both areas were different, too, but that between $B_1$ and $B_6$ was the highest (CCj=0.5). Probably this phenomenon is due to the great numbers of the pine trees appeared simulataneously. Content of the organic matter, N, P, K and Ca of soil in the burned area at the 5th years after the fires was lower than that of soil in the currently burned area.