• 한국재료학회지
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• 제25권11호
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• pp.577-582
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• 2015

The present study is concerned with the influence of niobium(Nb) addition and austenitizing temperature on the hardenability of low-carbon boron steels. The steel specimens were austenitized at different temperatures and cooled with different cooling rates using dilatometry; their microstructures and hardness were analyzed to estimate the hardenability. The addition of Nb hardly affected the transformation start and finish temperatures at lower austenitizing temperatures, whereas it significantly decreased the transformation finish temperature at higher austenitizing temperatures. This could be explained by the non-equilibrium segregation mechanism of boron atoms. When the Nb-added boron steel specimens were austenitized at higher temperatures, it is possible that Nb and carbon atoms present in the austenite phase retarded the diffusion of carbon towards the austenite grain boundaries during cooling due to the formation of NbC precipitate and Nb-C clusters, thus preventing the precipitation of $M_{23}(C,B)_6$ along the austenite grain boundaries and thereby improving the hardenability of the boron steels. As a result, because it considerably decreases the transformation finish temperature and prohibits the nucleation of proeutectoid ferrite even at the slow cooling rate of $3^{\circ}C/s$, irrespective of the austenitizing temperature, the addition of 0.05 wt.% Nb had nearly the same hardenability-enhancing effect as did the addition of 0.2 wt.% Mo.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2008년도 춘계학술발표대회 논문집
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• pp.155-158
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• 2008

Today, apartment is the primary housing type in Korea. In the past, there were many apartment floor plans in the same design way. There have been changes to complex and luxury plans in these days because people want to fit their own needs and wants to the plans. The primary purpose of this study is to analyze interior design trend of medium-large size apartment after year 2000. For that, this study used 7 different construction companies, 13 apartment complexes and 30 unit plan cases which were on sale from April 2007 to April 2008 in Seoul and the Metropolitan area. The results of analysis are as follows: First, most cases had 4LDK and 2bathroom with a dress-room. Second, characteristics of the interior design showed that the variety finish materials used in the units. For wall finish materials, wallpapers were used in mostly regardless in different areas. For floor finish materials, stone and tile were used in similar ratio in the entrance area whereas wood floor mostly was used in living room and kitchen areas. This study shows some significant characteristics of today's apartment even it has some limitations because of small amount of survey cases. More detailed and deeper study will be done continuously.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.513-533
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• 1994

The smooth surface after polishing of composite resin contributes to the patient's comfort, and appearance and longevity of the restoration. This study was performed for the quantitative analysis of the effects of the various finishing and polishing instruments on the surface roughness and reflectivity of the microfill, and hybrid composite resins. Cylindrical specimens 2mm thick and 10mm in diameter of Silux Plus, Durafill VS ; Z100, Prisma TPH, Brilliant, and Herculite XR composite resin were polymerized under the matrix strip. 18 specimens for each composite resin materials were divided into 6 groups ; 5 experimental groups were abraded with # 600 sand paper to remove resin-rich layer, except control. Thereafter, using diamond bur(Mani Dia-Burs), carbide bur(E. T. carbide set 4159), rubber point(Composite polishing kit), aluminum-oxide disk(Sof-Lex disk), polishing paste(Enhance system) ; each specimen was polished to its best achievable surface according to manufacturer's directions. Final polished surfaces were evaluated for the surface roughness with profilometer(${\alpha}$-step 200, Tencor instruments, USA) and for the reflectivity with image analyser(Omniment Image Analyser, Buehler, USA). The results were as follows. 1. Polishing paste or aluminum-oxide disk finish in the microfill, and hybrid composite resins was as smooth as matrix strip finish on the surface roughness test. 2. Polishing paste or aluminum-oxide disk finish in the microfill ; polishing paste finish in the hybrid composite resins was as reflective as matrix strip finish on the refectivity test. 3. For the polishing paste, there were no significant differences between the composite resin materials on the surface roughness and refectivity tests. 4. For the aluminum-oxide disk, the best result was obtained with the microfill composite resin on the surface roughness and reflectivity test. 5. Diamond bur, carbide bur, and rubber point were inappropriate for the final polishing instruments.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.118-119
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• 2019

The exterior finish not only has a relationship to the functionality of building, but also the spatial aesthetics and visual perception. Common exterior finishes are wood, stone or acrylic based and etc. However, these finishes have different attributes which can alter the quality of the architecture, such as durability, moisture and fire resistance. To make up for the short-comings of these materials, we have used iron based resources for optimization. However, iron materials are expensive, so they have limitations in general use. In this study, we have experimented with various forms of exterior finishes using cement, which is the most efficient and widely used building material with several economic advantages. We experimented with different materials to use as the formwork for the gloss of the cement matrix. As a result, the gloss show that order of urethane, steel, and wood material.

• 한국가구학회지
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• 제23권4호
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• pp.355-363
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• 2012

From the end of the 20th century, there has been increased interest for life Well-Being and LOHAS. Attracting the interest of consumers for eco-friendly materials, the furniture in the finish of the interior space of interest. In the finish of the interior space and living furniture, eco-friendly materials and the process of development and research has led to a surface treatment for reducing hazardous substances. By a combination of natural materials and the latest eco-friendly rating, recognized in LPM (Low Pressure Melamine) has been developed. LPM was used birch and eco-friendly materials, the development of student furniture can be expanded depending on the growth.

• 한국실내디자인학회논문집
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• 제21권1호
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• pp.177-185
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• 2012

The purpose of this study is to use as the basic data for design method in commercial space. So, we analyzed whether any emotion was induced by finishing materials in the commercial space. And we was to suggest expression methods of finish materials to induce in the emotional space. The results of this study are as follows : First, we could know that the emotional design is needed to enhance satisfaction of consumers. The role of finishing material is very important in emotional expression in the commercial space. Second, we extracted the adjectives vocabulary(14 pairs) to evaluate the space emotion. we could educe the four kinds of space emotion by Factor Analysis. In addition, we could arrange the emotional words to represent each space type(Decoration : 5 pairs, Expand : 4 pairs, Limitation : 3 pairs, Hierarchy : 2 pairs). Third, to use finishing materials and wall is very effective to induce the emotion in the emotional space. To use the color is good among the elements of finishing materials. Fourth, We could find that the center of the types of emotional space was induced with the boundary and the decoration. If we use contrasting colors and accent colors in the commercial space, we can induce the center and the boundary together. And if we use colorful or unusual patterns, we can induce the center and the decoration together. Fifth, To induce the expand, we should finish with one color in space. And To induce the center, we should finish with one type of the color or pattern and then we should partially use the contrast color and special pattern. the case of boundary, it is good method to part emphasize by color, texture and materials. And we can induce the decoration with materials and patterns.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.171-171
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• 2008

본 연구는 초음파 알루미늄 웨지 및 금 볼 본딩을 동시에 적용 가능한 본딩 Pad의 금속학적 안정성을 고려한 표층전극 형성 방법에 관한 것이다. 특히, 이동통신 및 전장용 모듈의 복합 및 융합화로 LTCC기판 패키징에 있어서 다양한 본딩 기술이 요구되고 있다. 전통적인 interconnection 기술인 Au ball 본딩 및 초음파 에너지를 이용한 Al wedge 본딩 기술이 동시에 사용되어야 하는 패키지 구조의 경우 본딩 패드의 표층전극 설계는 서로 상충되는 조건이 요구된다. 따라서, 본 연구에서는 LTCC기판의 표층전극의 Metal finish 방법으로 이용되는 ENEPIG(무전해 Ni/Pd/Au도금)공법으로 Au ball 본딩 및 초음파 Al wedge 본딩을 동시에 가능하게 하는 solution을 제시하여 패키징 자유도뿐만 아니라 Interconnection 신뢰성을 확보할 수 있었다.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2004년도 하계학술논문발표회 논문집
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• pp.3-8
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• 2004

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2000년도 춘계학술대회 논문집
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• pp.75-79
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• 2000

• 대한금속재료학회지
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• 제47권9호
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• pp.523-532
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• 2009

In this study, four API X80 linepipe steel specimens were fabricated with varying cooling rates and finish cooling temperatures, and their microstructures and crystallographic orientations were analyzed to investigate the effects of cooling conditions on their tensile and Charpy impact properties. All the specimens consisted of acicular ferrite, granular bainite, and secondary phases such as martensite and martensiteaustenite constituent. The volume fraction of secondary phases increased with increasing cooling rate, and the higher finish cooling temperature resulted in the reduction in volume fraction and grain size of secondary phases. According to the crystallographic orientation analysis data, the effective grain size and unit crack path decreased as fine acicular ferrites having a large amount of high-angle grain boundaries were homogeneously formed, thereby leading to the improvement of Charpy impact properties. The specimen fabricated with the higher cooling rate and lower finish cooling temperature had the highest upper shelf energy and the lowest energy transition temperature because it contained a large amount of fine secondary phases homogeneously distributed inside fine acicular ferrites, while its tensile properties well maintained.