• Title/Summary/Keyword: 연마지

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Effect of heat treatment of core fabricated by Ni-Cr alloy on marginal and internal fit (열처리가 Ni-Cr 합금으로 제작된 하부구조물의 변연 및 내면 간격에 미치는 영향)

  • Kim, Jae-Hong;Kim, Ki-Baek;Jung, Jae-Kwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.9
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    • pp.244-250
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    • 2017
  • The most important aspect determining the completeness of aprosthesis is itsmarginal and internal fit. Alloysare processed using a softening/hardening heat treatment methodin order to improve their mechanical, physical properties and polishing properties. To examinehow the heat treatment method affects the marginal and internal fit of the Ni-Cr alloy core,thirty dental stone models of the abutment of the mandibular left molar were manufactured.The Ni-Cr alloy coreswere manufactured by the dipping method for the experiment and dividedinto three groups; A for no heat treatment, B for softening heat treatment and C for hardening heat treatment. The marginal and internal fitsof all of the groups were measured by the silicone replica technique. A statistical analysis was performed using one-way ANOVA(${\alpha}=0.05$) in order to examine whether there is a significant difference in the average values of the marginal and internal fits among the three groups and it was found that themarginal fits (1, 6) were significantly different (p<0.05), but the internal fits (2, 3, 4, 5) were not significantly different (p>0.05). These results show that Ni-Cr alloys should not be processed bythe heat treatmentmethod.However, they need to be confirmed in further clinical application studies.

Particle Removal on Buffing Process After Copper CMP (구리 CMP 후 버핑 공정을 이용한 연마 입자 제거)

  • Shin, Woon-Ki;Park, Sun-Joon;Lee, Hyun-Seop;Jeong, Moon-Ki;Lee, Young-Kyun;Lee, Ho-Jun;Kim, Young-Min;Cho, Han-Chul;Joo, Suk-Bae;Jeong, Hae-Do
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.1
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    • pp.17-21
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    • 2011
  • Copper (Cu) had been attractive material due to its superior properties comparing to other metals such as aluminum or tungsten and considered as the best metal which can replace them as an interconnect metal in integrated circuits. CMP (Chemical Mechanical Polishing) technology enabled the production of excellent local and global planarization of microelectronic materials, which allow high resolution of photolithography process. Cu CMP is a complex removal process performed by chemical reaction and mechanical abrasion, which can make defects of its own such as a scratch, particle and dishing. The abrasive particles remain on the Cu surface, and become contaminations to make device yield and performance deteriorate. To remove the particle, buffing cleaning method used in post-CMP cleaning and buffing is the one of the most effective physical cleaning process. AE(Acoustic Emission) sensor was used to detect dynamic friction during the buffing process. When polishing is started, the sensor starts to be loaded and produces an electrical charge that is directly proportional to the applied force. Cleaning efficiency of Cu surface were measured by FE-SEM and AFM during the buffing process. The experimental result showed that particles removed with buffing process, it is possible to detect the particle removal efficiency through obtained signal by the AE sensor.

The Necessity for End-of-Life Care Education: A Preliminary Analysis with Interns at Two University Hospitals (임종돌봄에 대한 교육의 필요성: 2개 대학병원의 인턴을 대상으로 예비 분석)

  • Kim, Do Yeun;Kim, Kyong-Jee;Shin, Sung Joon;Kwon, Ivo;Nam, Eun Mi;Heo, Dae Seog;Lee, Soon Nam
    • Journal of Hospice and Palliative Care
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    • v.20 no.2
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    • pp.111-121
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    • 2017
  • Purpose: This study was performed to explore the current state of end-of-life (EoL) care education provided to new interns at two university hospitals. Methods: A questionnaire was given to incoming interns (N=64). The levels of acquired knowledge and experience of clinical observation were measured. Seven areas for self-assessment questions were identified and used to analyze the interns' attitudes towards EoL-related education and practice. Results: On average, participants learned five elements (nine in total) from EoL-related classes and two (seven in total) from clinical observation. The most frequently educated element was how to deliver bad news (96.9%) in the classroom setting and how to control physical symptoms (56.5%) in clinical observation. Less than 20% received training on EoL care communication, including discussion of advanced directives. Compared with participants who had no EoL training, those who had EoL training showed positive attitudes in all seven categories regarding overall satisfaction, interest and preparedness in relation to EoL-care classes and practice. Conclusion: Although interns are responsible for caring of dying patients, their EoL training in classroom and clinical settings was very insufficient. Further research should be conducted to establish an education system that provides sufficient knowledge and training on EoL care.

Effect on the Externally Stained IPS e.max Press Porcelain Due to Tooth Brushing (칫솔질이 IPS e.max Press 도재의 외부 stain에 미치는 영향)

  • Park, Chan;Lee, Gyeong-Je;Kim, Hee-Jung
    • Journal of Dental Rehabilitation and Applied Science
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    • v.28 no.2
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    • pp.213-221
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    • 2012
  • The purpose of this study was to evaluate the stability of external stain that long term attrition caused by tooth brushing affected the color variation of external stain of IPS e.max Press Porcelain. The specimen was made by IPS e.max Press LT ingots, and treated the shade of external staning as Orange, A, B, C, D After conducting horizontal toothbrush strokes about 11,000 / 22,000 / 44,000 / 66,000 / 88,000, Color changers of the external stained layer was measured with SpectroShade$^{tm}$ MICRO(MHT, Italy). The result of this study was obtained as follows: 1. After 11,000 strokes, the color changes of shade were greater in Orange shade than the other 4 shade groups. And even though toothbrush strokes were increased until 88,000, there were no statistical significant color changes about the external stain shade variation. 2. The amount of color variation about increasing of toothbrushing strokes was irregular(no consistent increasing, or decreasing), and it was no statistical significant changes According to these results, the long term tooth-brushing doesn't affect the changes of external stain about IPS e.max press porcelain. And it doesn't reduce the stability of external stain clinically. Later, it will be needed to study other factors affecting the external stain.

Growth of GaAs/AlGaAs Superlattice and HEMT Structures by MOCVD (MOCVD에 의한 GaAs/AlGaAs 초격자 및 HEMT 구조의 성장)

  • Kim, Moo-Sung;Kim, Yong;Eom, Kyung-Sook;Kim, Sung-Il;Min, Suk-Ki
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.2
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    • pp.81-92
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    • 1990
  • We developed the technologies of wuperlattice and HEMT structures grown by MOCVD, and their characterization. In the case of GaAs/AlGaAs superlattice, the periodicity, interface abruptness and Al compositional uniformity were confirmed through the shallow angle lapping technique and double crystal x-ray measurement. Photoluminesence spectra due to quantum size effect of isolated quantum wells were also observed. The heterojunction abruptness was estimated to be within 1 monolayer fluctuation by the analysis of the relation between PL FWHM(Full Width at Half Maximum) and well width. HEMT structure was successfully grown by MOCVD. The 2 dimensional electron gas formation at heterointerface in HEMT structure were evidenced through the C-V profile, SdH (Shubnikov-de Haas)oscillation and low temperature Hall measurement. Low field mobility were as high as $69,000cm^2/v.sec$ for a sheet carrier density of $5.5{\times}10^{11}cm^-2$ at 15K, and $41,200cm^2/v.sec$ for a sheet carrier density of $6.6{\times}10^{11}cm^-2$ at 77K. In addition, well defined SdH oscillation and quantized Hall plateaues were observed.

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A Comparative Study on Power Tool Manufacturers' Products Spec. and Design Development Features - By the Case Study on BOSCH, BLACK&DECKER and KEYANG Electrics- (전동공구 회사의 제품사양별 디자인개발특성 비교연구 -보슈(BOSCH), 블랙앤데커(BLACK&DECKER), 계양전기 사례를 중심으로 -)

  • 채승진
    • Archives of design research
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    • v.17 no.1
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    • pp.383-392
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    • 2004
  • The power tools is the product using working power generated by electric motor. Many companies are manufacturing numerous devices. Main features of tools are included various assembled products, small, light and solid and durable enough to match several standards. Fundamental requirements for the product is excellent performance and convenience for use. The quality of them depends on the equipped motor'(s) capability, accuracy of gear and endurance against worn-out. By adapting the state-of-the-art parts, they could be used in the place from home to heavy industry broadly. They can be classified electronic drills, grinders, saws and sanders families for the household appliances. For industrial tools, bore drill, grinder, polisher, and driver drill are classified as special and high priced group. This study presents the strategy of power tool development of BOSCH, BLACK&DECKER and KEYANG. Their products were analyzed in terms of product line and product mix concept. Then they are examined by design elements, such as color, shape and material for housing. As an analysis method, the image scale parameter and criteria were applied to each company's product.

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Characteristics of Concrete Sidewalk Block Manufactured Using Stone Powder Sludge and photocatalytic agent (석분슬러지와 광촉매제를 사용한 콘크리트 보도블록의 특성)

  • Jung, Yong-Wook;Lee, Seung-Han;Choi, Jong-Oh
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4237-4244
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    • 2015
  • This study examined the efflorescence characteristics of a concrete sidewalk block manufactured using recycled stone powder sludge and photocatalytic generated by surface polishing during the sidewalk block manufacturing process. The study evaluated the characteristics of the sidewalk block in terms of its quality, based on the amount of stone powder sludge used, efflorescence, and further based on the mixing ratio and number of applications of the photocatalytic. The experimental results indicated that heavy metals such as lead, hexavalent chrome, cadmium, and mercury were not present in the concrete sidewalk block, thereby confirming the effectiveness of the recycled stone powder sludge. The optimum mixing ratio of used in the concrete sidewalk block (for satisfying KS standard values such as water absorption ratio and flexural strength) was found to be 20%. The concrete sidewalk block incorporating the stone powder sludge and photocatalytic exhibited a water absorption ratio of 5.4% and flexural strength of 5.2 MPa, thereby satisfying the quality standards. Additionally, when the photocatalytic was used, efflorescence did not occur even at the low temperature of $-5^{\circ}C$, and the by the sidewalk block was found to be 70% under normal conditions and 68% when subjected to an accelerated weathering test.

Fabrication of complete denture using digital technology in patient with mandibular deviation: a case report (하악 편위 환자에서 디지털 방식을 이용한 총의치 제작 증례)

  • Lee, Eunsu;Park, Juyoung;Park, Chan;Yun, Kwi-Dug;Lim, Hyun-Pil;Park, Sangwon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.38 no.1
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    • pp.34-41
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    • 2022
  • Recently, digital technology and computer-aided design/computer-aided manufacturing (CAD/CAM) environment have changed the clinician treatment method in the fabrication of dentures. The denture manufacturing method with CAD/CAM technology simplifies the treatment and laboratory process to reduce the occurrence of errors and provides clinical efficiency and convenience. In this case, complete dentures were fabricated using stereolithography (SLA)-based 3D printing in patient with mandibular deviation. Recording base were produced in a digital model obtained with an intraoral scanner, and after recording a jaw relation in the occlusal rim, a definitive impression was obtained with polyvinyl siloxane impression material. In addition, facial scan data with occlusal rim was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work. Artificial teeth were arranged through a CAD program, and a gingival festooning was performed. The definitive dentures were printed by SLA-based 3D printer using a Food and Drug Administration (FDA)-approved liquid photocurable resin. The denture showed adequate retention, support and stability, and results were satisfied functionally and aesthetically.

The Role of Applied Nutritionist (영양과 지역사회 개발 - 2. 영양지도원(營養指導員)의 역할(役割) -)

  • Chun, Sung-Kyu
    • Journal of Nutrition and Health
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    • v.9 no.4
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    • pp.4-8
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    • 1976
  • 영양지도원(營養指導員)은 자신(自身)이 알고 있는 기술(技術)을 다른 사람에게 전달(傳達)하여 그 사람으로 하여금 지도원(指導員)이 원하는 방향(方向)으로 행동(行動)을 하도록 해야 한다. 따라서 다른 사람을 지도(指導)하려면은 우선 지도원 자신(指導員自身)의 우수한 자질(資質)"이 필요(必要) 하며 이를 위(爲)하여 기술자(技術者)로서의 연마(硏磨)와 겸(兼)하여 인간(人間)의 지도자(指導者)로서의 수양(修養)을 쌓아야 한다. 그리하여 영양개선(營養改善) 의 선도적(先導的) 점화자(點火者)로 "뒤에서 계속 미는" 지원자(支援者)로서의 역할(役割)을 수행(遂行)하여야 한다. (1) 현직능별(現職能別) 영양지도원(營養指導員)의 범위(範圍)를 보건소(保健所)의 보건지도원(保健指導員), 농촌지도소(農村指導所)의 생활지도요원(生活指導要員), 군면(郡面)의 행정지도요원(行政指導要員), 농협(農協)의 부여지도요원(婦女指導要員), 의료계(醫療界)의 의사(醫師), 간호원(看護員), 조산원(助産員), 학교(學校) 교육기관(敎育機關)의 교사(敎師), 영양사(營養士), 영리회사(營利會社)의 사원(社員) 등을 들 수 있다. (2) 지도대상(指導對象)과 그 장소(場所)는 공장(工場), 학교(學校), 훈련장(訓練場), 병원(病院), 복지시설(福祉施設)과 공동취사(共同炊事) 재해시등(災害時等)의 집단급식장(集團給食場)과 이를 이용(利用)하는 對象者(대상자) 도시(都市) 농촌(農村)의 일반가정(一般家庭)의 주민(住民), 그리고 교실(敎室)에서 학교교과목(學校敎科目)을 통(通)한 학생(學生)의 학습(學習) 새마을운동(運動) 공보시설(公報施設)을 통(通)하여 대중(大衆)에게 "지도(指導)를 지도원(指導員)이" 전개(展開)할 수 있다. (3) 지도방법(指導方法)은 일반적(一般的) 학교교육과정(學校敎育過程)의 교육방법(敎育方法)을 적용(適用)하되 교외교육(校外敎育)이라는 점(點)을 잊어서는 안된다. 현실적(現實的)으로 이론(理論)과 경험(經驗)을 병행활용(倂行活用)하며 영양학(營養學)의 연구결과(硏究結果)가 반드시 또 는 곧 가정생활(家庭生活) 개인생활(個人生活)에 적응(適應)되는 것이 아니며, 행동화(行動化)되지 않는 지식(知識)과 기술(技術)은 무용(無用)하게 되므로 "다고 말 할 수 있다. 따라서 영양개선(營養改善)을 지도(指導)하는 지도원(指導員)은 받아들이는 가정(家庭)이나 개인(個人)의 입장(立場)에서 여러 가지 여건을 파악 최대공약수(最大公約數)의 가능치(可能値)를 알아내서 지도(指導)해야 된다. (4) 영양지도(營養指導)는 기술(技術)이 ,포함(包含)되어 있기 때문에 기술(技術)의 전달과정(傳達過程)을 분석(分析)해야 되고 (5) 지도원(指導員) 자신의 무장(武裝)을 위(爲)하여 자신(自身)의 기술지도(技術指導) 방법(方法), 인간지도자(人間指導者)로서의 능력향상(能力向上)을 독서(讀書), 교육(敎育), 훈련(訓練) 을 통(通)하여 배워 기술자(技術者)로서 인간지도자(人間指導者)로서 전달자(傳達者)로 서의 교양(敎養)을 가져야 한다. (6) 지도원(指導員)의 활동성과(活動成果)는 지도원(指導員) 자신의 열의(熱意)와 받아들이는 사람의 열의(熱意)에 의(依)하여 좌우(左右)된다. 즉(卽) 지도원(指導員)의 열의(熱意)${\times}$피지도자(被指導者)의 열의(熱意)=지도성과(指導成果) $[L{\times}P=f(L{\cdot}P)]$로 나타난다. 결론적(結論的)으로 지도원(指導員)은 영양개선(營養改善)의 전문적(專門的) 각 요소(各要素)를 깊이 알고 이것을 다시 종합(綜合)하고 체계화(體系化)할 줄 알며 직능별(職能別) 각 지도원(各指導員)과의 상호(相互) 협조(協助)로 서로 보완(補完)하고 새마을 운동(運動)과 그 직장(職場) 또는 환경(環境)여건에 결부(結付)되고 현실적(現實的)으로 행동화(行動化)할 수 있는 단계적(的) 장단기계획(長短期計劃)과 평가방법(評價方法)을 숙지(熟知)하여 또 지도방법(指導方法)에 필요(必要)한 교재(敎材)를 충실(充實)히 준비하여 자신(自身)의 실력(實力)을 충분(充分)히 발휘할 수 있도록 하여 자기 열의(熱意)를 다하고" 영양개선(營養改善)의 선도적(先導的) 점화자(點火者)로서 "계속 뒤에서 미는" 지원자(支援者)로서 사명(使命)을 다할 때 그 역할(役割)을 다하는 것이다.

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A Study on the Reactionism Tendency in the Calligraphy Style of Changam(蒼巖) Lee Sam-man(李三晩) (창암(蒼巖) 이삼만(李三晩)의 서풍(書風)에 나타난 복고적 성향 고찰)

  • Park, Jae-bok
    • (The)Study of the Eastern Classic
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    • no.49
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    • pp.357-392
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    • 2012
  • An author is bound to reflect his or her own thinking and inclination in his or her works. The previous studies on Changam(蒼巖), however, mostly discussed the aesthetics in the forms of his introductions and works, hardly addressing his thinking reflected in his works. Recognizing that he had the "reactionism tendency" unlike the Bukhak-School(北學派), which was the cultural mainstream of the days, this study examined the specific patterns of the reactionism calligraphy style in his learning and calligraphy processes and works. He loved to write xing-cao-shu(行草書) with a focus on the materials written in one's own calligraphy, but he also emphasized that one should obtain the force of his or her calligraphy style by mastering kai shu before calligraphy xing cao shu. He thus left a lot of works in the xiao kai(小楷) of the Wang Xzhi(王羲之) calligraphy style throughout his life, which is attributed to the influences of the calligraphers of dong-guk-jin-che(東國眞體) in the latter half of Joseon(朝鮮) and those of Lee Gwang-sa(李匡師), his master in spirit. He is distinguished from the other calligraphers of the times in that he made lifelong efforts to compensate for the lacking stroke of the pen in the model calligraphy of Wang Xzhi. In the calligraphy theory, he put importance on the traditional method of Han-Wei(漢魏) and took Cai Yong(蔡邕) and Zhong Yao(鍾繇) as the fundamentals. For da kai(大楷), he constantly practiced the with the stroke of the pen by added to it, the letters of Wei(魏) Wudi(武帝), by Yan Zhenqing(顔眞卿), and letters of Kim Saeng(金生). His late works using the intended conception of and , in particular, present his unique calligraphy style that added the crooked forms of to the shapes of characters of that were in the kai-shu(楷書) style. It is a limitation that a considerable number of calligraphy materials Changam studied or consulted were either reprint copy or block book rather than original rubbing edition due to time and space restrictions. However, it is also true that those restrictions made an important contribution to his creation of his unique calligraphy style with deep local colors at the result of his constant efforts.