• 한국지구과학회지
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• 제43권4호
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• pp.532-538
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• 2022

Under anoxic conditions, this study investigated removal of dissolved As(III) by Si and Al oxides including natural sand, chemically washed sand (silica), alumina, and activated alumina. Despite the similar surface area, natural sand showed greater extents of As(III) sorption than chemically washed sand. This was likely due to the high reactivity of Fe(oxyhydr)oxide impurities on the surface of natural sand. For both sands, As(III) sorption was the greatest at pH 7.1, in agreement with the weakly dissociating tendency of arsenous acid. Also, the least sorption was observed at pH 9.6. At basic pH, elevated silicate, which originated from the dissolution of silica in sands, would compete with As(III) for sorption. Due to the highest surface area, activated alumina was found to quantitatively immobilize the initially added As(III) (6.0×10^-7-2.0×10^-5 M). Alumina showed As(III) sorption compared to or greater than chemically washed sand, although the former had less than 6% of the surface of area the latter. The greater reactivity of alumina than chemically washed sand can be explained by using the shared charge of oxygen.

• 한국환경복원기술학회지
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• 제16권4호
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• pp.65-81
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• 2013

Urban sprawl has been the limits of traffic accommodate and the supply road. Thus, Light Rail Transit(LRT) has been proposed as the best alternative. Owing to landscape damage from construction of LRT, landscape planning should be considered seriously in the urban planning step. This paper therefore seeks to determine landscape improvement direction of LRT pier. First, the methods in this study shared landscape improvement direction type of LRT pier through previous studies such as planting of surface(30%, 60%, 90% planting of surface), graphic(character, commercial advertising, symbol), and surface treatment type(exposed concrete, white painting, pattern dies). Next, respondent evaluated 3D simulated landscape image accordingly shared types by preference and landscape adjectives using in streetscape evaluation. As a result, visual preference was the highest in planting type of surface and the lowest in the surface treatment type. Covering 60%(4.48) in planting type of surface was the highest. Because it is similar to the golden ratio considering the visual principle, we will need to take advantage through the result of this paper. Also, most landscape improvement direction which satisfied with significant level showed a positive effect from landscape improvement. Comprehensively based on these results, it suggests desirable landscape improvement direction of LRT pier in the city for solution of landscape inhibition problem.

• Restorative Dentistry and Endodontics
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• 제17권1호
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• pp.166-180
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• 1992

One disadvantage of Glass Ionomer Cement Restoration is the difficulty in polishing. To find the appropriate polishing method, we polished the surface of Glass Ionomer Cement Restorations by 11 combination methods serially using disks shared with large-small particles and evaluated the polishing process in terms of surface roughness, surface roughness curve, and SEM findings. In addition, a visible light curing type bonding material was applied to evaluate the possible improvement in surface properties. The following results were obtained. 1. The disk surface of Glass Ionomer Cement was polished serially by disks with superfine particles, but it didn't become smooth. 2. The surface of Microfilled Composite resin became smoother as using a disk with finer particles. 3. When a visible light curing type bonding material was applied in finishing process, the surface of Glass Ionomer Cement became smooth as much as the applied matrix.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.670-674
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• 1996

In automated search of a design database to support mechanical design, it is necessaryto recognize a shape pattern which represents a design object. This paper introduces the concept of a surface relation graph (SRG) for recognizing shape patterns from a 3D boundary representation scheme of a solid model(a B-rep model). In SRG, the nodes and arcs correspond to the faces and edges shared by two adjacent faces, respectively. An attribute assigned to an arc is given by an integer which discriminates the relationship between two adjacent faces. The + sign of the integer represents the geometric convexity of the solid, and the -sign the concivity at the shared edge. The input shape is recognized by comparison with the predefined features which are subgraphs of the SRG. A hierarchyof the database for upporting the design is presented. A search for the design database is also discussed. The usefulness of this method is illustrated by some application results.

• 한국실내디자인학회논문집
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• 제20권1호
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• pp.173-181
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• 2011

Contemporary architecture has shown interest in surface after breaking off the relation with structure. Also, the development of contemporary media has brought the great change to the surface of architecture. Interaction among the people, architecture, and environment is also the main point of interest in adapting the role of media to the architecture. But contemporary media itself have been applied on surface in architecture lately. So, it is purpose of the study to analyze the contemporary media characteristics application on the surfaces of EXPO pavilions based on the related characteristics of interaction effects. The categories and the contents for the frame of case studies were arranged through document research and field study. Case studies were focused on the pavilions of the World Exposition Shanghai China 2010. Surface can make the interaction between human and architecture more dramatically by the application the role of media. It was analyzed through the study that the interaction level of people is the important issue shared in digital or analog media application on surface of pavilion. The complementary relationship between surface of contemporary architecture and contemporary media can be manipulated and enriched by the application of various style of media on surface.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.139-148
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• 2006

Catmull-Clark subdivision scheme provides a powerful method for building smooth and complex surfaces. But the number of faces in the uniformly refined meshes increases exponentially with respect to subdivision depth. Adaptive tessellation reduces the number of faces needed to yield a smooth approximation to the limit surface and, consequently, makes the rendering process more efficient. In this paper, we present a new adaptive tessellation method for general Catmull-Clark subdivision surfaces. Different from previous control mesh refinement based approaches, which generate approximate meshes that usually do not interpolate the limit surface, the new method is based on direct evaluation of the limit surface to generate an inscribed polyhedron of the limit surface. With explicit evaluation of general Catmull-Clark subdivision surfaces becoming available, the new adaptive tessellation method can precisely measure error for every point of the limit surface. Hence, it has complete control of the accuracy of the tessellation result. Cracks are avoided by using a recursive color marking process to ensure that adjacent patches or subpatches use the same limit surface points in the construction of the shared boundary. The new method performs limit surface evaluation only at points that are needed for the final rendering process. Therefore it is very fast and memory efficient. The new method is presented for the general Catmull-Clark subdivision scheme. But it can be used for any subdivision scheme that has an explicit evaluation method for its limit surface.

• 한국생산제조학회지
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• 제8권2호
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• pp.56-61
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• 1999

The fine blanking is a process of pressworking which makes possible to produce thick sheet metal parts of finished sheared surface and close dimensional accuracy over whole material thickness in single blanki ng operation. Fine blanked parts in general are characterized by their cleanly sheared surface over the whole sock thickness and accurate size for the specific functions. The fine blanking technology is urgently needed to remove secondary operations which are necessary in conventional blanking operation and cost reduction. In this study, the effect of material texture and vee-ring on parts for automobile is investigated by experimental observation and analysis.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1527-1533
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• 2011

The reaction of gas-phase atomic hydrogen with oxygen atoms chemisorbed on a silicon surface is studied by use of the classical trajectory approach. We have calculated the probability of the OH formation and energy deposit of the reaction exothermicity in the newly formed OH in the gas-surface reaction H(g) + O(ad)/Si${\rightarrow}$ OH(g) + Si. All reactive events occur in a single impact collision on a subpicosecond scale, following the Eley-Rideal mechanism. These events occur in a localized region around the adatom site on the surface. The reaction probability is dependent upon the gas temperature and shows the maximum near 1000 K, but it is essentially independent of the surface temperature. The reaction probability is also independent upon the initial excitation of the O-Si vibration. The reaction energy available for the product state is carried away by the desorbing OH in its translational and vibrational motions. When the initial excitation of the O-Si vibration increases, translational and vibrational energies of OH rise accordingly, while the energy shared by rotational motion varies only slightly. Flow of energy between the reaction zone and the solid has been incorporated in trajectory calculations, but the amount of energy propagated into the solid is only a few percent of the available energy released in the OH formation.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3650-3655
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• 2013

파인블랭킹 금형을 제작하는 주목적은 전단면의 크기를 최대가 되도록 하기 위함이다. 본 연구에서는 전단면의 크기에 가장 크게 영향을 미치는 클리어런스는 재료 두께의 1%로 고정시키고 전단라인에서 Vee-Ring 중심까지의 거리 변화, V-Ring 각도의 변화, 전단 속도를 변화시키면서 전단 면적의 크기 변화를 연구 고찰하였다. 각 실험으로부터 시편을 채취하여 전단면의 크기를 분석한 결과 V-링의 거리는 2mm, 각도는 외측$45^{\circ}$/내측$30^{\circ}$일 때, 전단 속도는 6.4m/min일 때 전단면의 크기가 가장 크게 됨을 알 수 있었다.

• 한국실내디자인학회논문집
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• 제19권3호
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• pp.38-45
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• 2010

Surface has been an important issue in contemporary architecture. That originates in structural freedom of surface since the end of modern architecture and the current stream of surface becoming an identity of building. Development of digital-media has brought a great change to our society in general. Digital-media is characterized by use of digital-information and interactive communication. Digital-media has been applied on surface in contemporary architecture lately. It is a purpose of the study to analyze the characteristics of digital-media application on surface based on the related characteristics of installation art. The categories and the contents for the frame of case analysis were arranged through document research. The foreign and domestic cases of digital-media application were analyzed based on the frame of analysis. Digital-media, which is installed on surface, is interacted with human and surroundings. It enhances emotional communication between human and architecture. Surface is not any more a simple fixture but an interactive creature. It makes surface more dynamically and fluidly that the course of light and human movement affect on digital-media. Surface itself is also turned into an object of art. It reflects the interweaving characteristics between contemporary architecture and installation art. It was analyzed through the study that emotional level of people is the important issue shared in digital-media application on surface and installation art. The complementary relationship between surface of contemporary architecture and installation art can be manipulated by the application of digital-media on surface.