• 한국진공학회지
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• 제19권2호
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• pp.96-104
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• 2010

NIL, S-FIL과 같은 각인 기술(Imprinting lithography)를 적용하기 위한 투명하고 단단한 복제 틀(replica hard mold)을 제작하여 고가의 원판(master)와 패턴이 형성되는 기판과의 접촉을 근본적으로 방지해 경제적인 공정이 가능함을 제안한다. 실리콘 웨이퍼(Si wafer)와 같은 원판(master)과 패턴 형성 시 사용되는 기판과 직접적인 접촉을 방지하기 위해 우선 액상 공정을 이용하여 비접착성 표면처리된 고분자 복제(polymer copy)를 매개체(carrier)로 단단한 복제 틀을 제작한다. 이렇게 제작된 단단한 복제 틀(replica hard mold)는 유리와 거의 같은 강도와 투명도를 나타내며, 각인 공정(imprinting process)에서 석영 틀, 실리콘 웨이퍼(quartz mold, Si wafer)과 같이 값비싼 원판(master)의 직접 사용을 대체하여 성공적으로 패턴을 구현할 수 있다.

• 산업공학
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• 제12권1호
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• pp.68-78
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• 1999

A noncircular cutting such as a piston cutting has depended on the copy-machining because of its complex shape. But the copy-machining needs a master model and brings about a low quality of the piston caused by being worn out of the master model. And the lower cutting speed reduces the productivity. In this paper, for solving these problems, a specialized software system and its subsequent procedure are presented. The shape of a piston consists of an oval, an offset, recesses, and eccentricities. The paper describes these shapes as a consistent equation that is a function of the rotational angle and the position of longitudinal direction(Z-axis). It is simple to define the characteristic geometry of a piston and to generate a tool path for CNC machining. This paper proposes the a proper structure of a 4-axes CNC(Computerized Numerical Control) lathe for machining the piston. As well as X-axis and Z-axis, are attached to the machine a C-axis for rotation and a Y-axis for higher speedy prismatic motion parallel to X-axis.

• Structural Engineering and Mechanics
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• 제4권1호
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• pp.73-89
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• 1996

In Lagrangian mechanics, attention is directed at the body as it moves through space. The region occupied by the body is called a configuration. All body points are labelled by the position they would have if the body were to occupy a chosen reference configuration. The reference configuration can be regarded as an extra fictional copy where notes are kept. As the body moves and deforms, it is important to correctly observe the use of each configuration for computational purposes. The description of strain is particularly important. The present work establishes clearly the role of each configuration in total and in incremental forms. This work also details the differences between gradient and configurational calculus.

• 대한안전경영과학회지
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• 제6권3호
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• pp.327-337
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• 2004

The soaring increase in the number of Internet users combined with the constant computerization of business process has created new opportunities for computer criminals and terrorist. Fortunately, the computer security field is also progressing at a brisk rate. In particular, the field of computer forensics brings new ways of preserving and analyzing evidence related to computer crime. Computer forensics is a new emerging professions of the 21st century. It is the collection, preservation, analysis, and presentation of computer related evidence. For this reason, the various technology of computer forensics is regarded as a powerful tool for suppressing computer crime. Our aims is to introduce the overview of computer forensics technology. We also present the survey results of the state of the art of computer forensics in the domestics and of foreign country.

• 대한치과보철학회지
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• 제39권3호
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• pp.243-249
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• 2001

Statement of the problem. The interest in all-ceramic restorations has increased as more techniques have become available. With the introduction of machinable dental ceramics and CAD/CAM systems or Copy-milling systems there is a need for evaluating the quality levels of these new fabrication techniques. Purpose. This study was to evaluate the fitting accuracy of machined all-ceramic crowns made out of an industrially prefabricated feldspathic porcelain. Material and Methods. Three master models with different cutting depth (0.8mm/1.0mm/1.2mm)were produced using a palladium-silver alloy. A total of 36 working dies, 12 of each form, was used for the modellation of prototype resin copings and 36 additional crowns, 12 of each cutting depth, were produced by using the $CEREC^{(R)}2$ system for all crowns. The maginal fit of all 72 crowns was then evaluated on their respective master die at 54 circularly staggered points of measurement per crown under a fixation pressure of 30 N by using a computerized video image system. Results. The medians of the copy-milled $CELAY^{(R)}$ crowns ranged from 29 to $36{\mu}m$. The highest value for the marginal gap was found in group B (cutting depth 1.0mm) at $107{\mu}m$. The median for the $CEREC^{(R)}2$ crowns was found between 43.5 and $70{\mu}m$. The maximum values for all three groups ranged from $181{\mu}m$ to $286{\mu}m$. With $286{\mu}m$ the highest value for marginal gap was found in group C. the Kruskal-Wallis test and multiple comparisons analysis procedure revealed a significant influence of the production technique on the marginal fit in all three groups (p<0,02). Conclusion. 1. The $CELAY^{(R)}$ system is capable to produce all-ceramic crowns with a significantly better marginal fit than the $CEREC^{(R)}2$ system. 2. As far as premolar crowns produced with the $CEREC^{(R)}2$ system are concerned, the cutting depth has a significant influence on fitting accuracy. 3. The production of crowns with an acceptable marginal fit is possible with both systems. However, adhesive luting is recommended for milled feldspathic porcelain crowns.

• 대한치과보철학회지
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• 제35권2호
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• pp.417-430
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• 1997

The purpose of this study was to compare the fracture resistance of copy-milled and conventional In-Ceram crown. Four groups of ten uniform sized all-ceramic crowns were fabricated. In-Ceram Spinell and In-Ceram Alumina crowns were fabricated as control group, Celay In-Ceram Spinell and Celay In-Ceram Alumina crowns were fabricated as test group. All specimen were cemented on stainless steel master die with resin cement, and stored in $37^{\circ}C$ water for 1 day prior to loading in Instron testing machine. Using a steel ball at a crosshead surfed of 0.5mm/min, the crowns were loaded at $30^{\circ}C$ angle until catastrophic failure occurred. The results obtained were as follows : 1. With the value of $984.8N{\pm}103.67N$, the strength of Celay In-Ceram Alumina crowns had a significantly higher fracture strength than conventional In-Ceram Alumina crowns ($876.2N{\pm}92.20N$) (P<0.05) 2. The fracture strength of Celay In-Ceram Spinell crowns($706.3{\pm}70.59N$) was greater than that of conventional In-Ceram Spinell crowns($687.4{\pm}90.26N$), but there was no significant difference(P>0.05). 3. The In-Ceram Alumina crowns had a significantly higher fracture strength than In-Ceram Spinell crowns in both methods(P<0.05). 4. Ther order of fracture strength was as followed : Celay In-Ceram Alumina, In-Ceram Alumina, Celay In-Ceram Spinell and In-Ceram Spinell crowns

• 한국문헌정보학회지
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• 제25권
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• pp.415-444
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• 1993

Chiyou Park(박치유) published Bang-kak-bon(방각본) at Taein(태인) between 1799-1806 with Ichae Jun( 전이채). They published Sa-yo-chwi-sun(사요취선) and Sa-moon-you-chwi-cho(사문류취초) in 1799. Between 1800-1806 they published Taemyongyoolsi(대명율시). Kongjatongki(공자통기). Hyokyongtaei(효경대의), Tongjaseup(동자습), Komoonchunchip(고문전집), Kongjakao(공자가어), Nongkachipsung(농가집성), and Koohwangcharlyo(구황촬요) until they departed each other in publication of Bang-kak-bon(방각본), In 1823 Chiyou Park(박치유) published again Sayochwisun(사요취선) at Kookockchae (구곡제). He published Taeseungkisinronsopilsacki(대승기신논소필삭기) and Chackpupkwikam(작법구감) between 1815-1827 with Backpataesa(백파대사) who was a Buddhism Monk of Woonmoon-am(운문암) in Backyang Mountain(백양산), Backpataesa(백파대사) was born in 1767, became a monk in 1784 and died in 1851. Backpa(백파) was a famous Budhism scholar who disputed the truth of Zen (선) with Choosa, Chunghee Kim We (추사김정희). He rewrote Taeseungk.isinronso-pilsacki(대승기신논소필삭기), Chackpupkwikam (작법구감), and Zenmoonsookyong (신문수경). Chasun (자선) of Songdynasty (송조) rewrote Pilsakcki(필삭기) before Backpa(백파), which was published at Myouduck-am(묘덕암) of Myongdynasty(명조). It was republshed in Korea several times which are called Sankyesa Copy(쌍계사본) of Back-am(백암), Suckwangsa Copy(석왕사본) of Hamwol(함월), Bongchungsa Copy(봉정사본) of Hoeun(호은), Woonmoon-am Copy(운문암본) of Backpa(백파). Chackpupkwikam(작법구감) is a book of Buddism worsip form which was made of Chaepanmoon (제반문), Paneumchip(범음집), Chineunchip진음집). As a Bangkakbon(방각본) publisher, Chiyou Park believed in Buddhism so heartily that be published Bangkakbon(방각본) and Amkakbon(암각본) which are saved until today.

• 한국정밀공학회지
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• 제22권12호
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• pp.16-21
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• 2005

Photonic crystals, periodic structure with a high refractive index contrast modulation, have recently become very interesting platform for the manipulation of light. The existence of a photonic bandgap, a frequency range in which the propagation of light is prevented in all directions, makes photonic crystal very useful in application where the spatial localization of light is required, for example waveguide, beam splitter, and cavity. However, the fabrication of 3 dimensional photonic crystals is still difficult process. A concept that has recently attracted a lot of attention is a planar photonic crystal based on a dielectric membrane, suspended in the air and perforated with two dimensional lattice of hole. The fabrication of Si master with pillar structure using hot embossing process is investigated for two dimensional, low-index-contrast photonic crystal waveguide. From our research we show that the multiple stamp copy process proved to be feasible and useful.

• 동양고전연구
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• 제41호
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• pp.211-247
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• 2010

이 글은 박순호 교수가 소장한 <정향전>의 이본을 분석하여 그 이본적 위상과 가치를 살피는 것을 목적으로 한다. 박순호본 <정향전>은 한 책 안에 한문본과 한글본이 같이 묶여 있다는 것이 특이하다. 박순호본 <정향전>은 서울의 장동에서, 한문본은 1934년에, 한글본은 1945년에 필사된 것으로 보이며, 천리대본과 비교할 때 한문 박본에는 생략과 축약, 추가 현상이 보이고, 선행 연구에서 천리대본을 선본(善本)이라고 주장한 바와는 달리 천리대본에는 오류가 잦고 오히려 한문 박본에 그러한 오류가 정정되어 있음을 발견할 수 있다. 비교 과정에서 드러난 결과 가운데 하나는 만송본이 천리대본을, 도남본이 만송본을 축약한 것이라는 선행 연구 역시 바로잡혀야 함을 알 수 있었다. 한문 박본은 천리대본보다는 만송본이나 도남본과 유사하고, 그 중에서도 만송본과 더욱 유사한 계열에 속한다. 한문본에는 양녕대군의 위선에 대한 표현이 약화되어 있는 반면에 양녕대군 개인의 부정적 성격은 부각되어 있다. 또 양녕대군의 심리 묘사는 약화되어 있고, 정향의 미모는 부각되어 있다. 한글본은 한문본을 축자 번역하는 것을 원칙으로 했으며, 미세하게 생략, 축약, 첨가, 변환의 현상이 보인다. 한글본에는 문호 혹은 문벌 의식이 가급적 보이지 않고, 양녕대군의 위선과 그의 부정적 성격을 드러내는 부분이 생략되어 있으며, 한시나 전고 등 한문학에 정통하지 않은 이가 보기에는 어려운 어절 등이 생략, 축약되어 있다. 박순호본 <정향전>이 지니는 가장 큰 가치는 한문본과 한글본이 합철되어 있다는 유통상의 특징이다. 이는 <정향전>의 다른 이본, 혹은 다른 고전소설의 유통 형태에서는 아직까지는 발견되지 않은 독특한 방식이다. 이러한 방식이 지니는 가장 큰 의의는 한문본의 향유자가 더 이상 정보의 독점을 꾀하지 않고 한문을 모르고 한글만을 아는 이들에게도 정보를 공유하려고 했다는 점이다.

• 한국통신학회논문지
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• 제29권3B호
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• pp.375-390
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• 2004

네임 서비스 시스템은 도메인 네임을 인터넷 주소로 또는 역으로 인터넷 주소를 도메인 네임으로 변화하는 서비스를 제공하며 웹, 이메일, 파일전송 등의 모든 인터넷 응용이 가장 먼저 사용하는 인터넷에서 가장 중요한 서비스 중의 하나이다. 본 논문에서는 상위 레벨의 대규모 도메인을 가정하여, 이 도메인에 대한 서비스를 제공하는 네임서버를 중심으로 성능 향상 및 신뢰성 제고의 방안을 제시하고, 테스트베드 구축 띤 성능 실험을 통해 이의 실현 가능성을 검증한다. 제안한 구조는 이중화된 네임서버를 가정하여 부하 분담 및 고신뢰성 달성이라는 두 가지 목표를 동시에 이루고자 하였다. 또한 매스터 네임서버의 데이터 갱신을 위해 동적 갱신 방식을 사용하였고, 슬레이브 네임서버고의 데이터 전송을 위해 IXFR(Incremental Zone Transfer)을 사용하여 서버의 부담을 최소화하고자 하였다. 테스트 베드의 실험 결과를 실제 구축될 시스템에 적용할 경우, 향후 서버에의 부하 증가에 효율적으로 대처할 수 있으며 시스템의 다운이나 오동자의 경우에도 연속적인 서비스 수행이 가능하다고 판단된다.