• Journal of the Korean Applied Science and Technology
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• v.40 no.4
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• pp.913-923
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• 2023

In this study, a triboelectric nanogenerator was fabricated using the composite of teflon-based polymer and graphene flower, which are stable in air and have relatively high electronegativity. The composite was used to fabricate an electronegative layer of a nanogenerator using a spin-coating method. For the electropositive layer, a zinc oxide film was prepared using a sol-gel method. The fabricated triboelectric nanogenerator produced a maximum power of about 44 ㎼. In conclusion, since all the active layers of the triboelectric nanogenerator was made by the solution process, it is scalable to a large area.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.102-108
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• 2013

In manufacturing of solution-processed organic electronic devices, a spin coating method is frequently used, but which has a big problem. Solvent in a solution has a decisive effect such as physical and chemical damage for successive solution-based film deposition. Such a severe damage by solvent restricts for fabricating building blocks of multi-layered films from solutions. In this work, it will be shown that a proper combination of well-known solvents gives a chance to fabricate multi-layered film, also this new method was applied to make organic field effect transistor. Two types of bottom gate, bottom contact transistors were fabricated, one of which is fabricated by conventional single spin coating method, the other fabricated by double spin coating method. Compared with the electrical characteristics in a single spin coated transistor, the leakage current between source and gate electrode was decreased, ON state current was increased, and the extracted saturation mobility was multiplied more than 2.7 time for double spin coated transistors. It is suggested that the multiple coated gate dielectric structure is more desirable for high performance organic ferroelectric field effect transistors.

• Korean Journal of Heritage: History & Science
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• v.47 no.4
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• pp.48-57
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• 2014

More than 30 lead beads have been excavated from buddhist temples and sites but the production times are unknown the origin. The aim of this study is to estimate manufacturing technique and provenance of 11 beads through the chemical composition and isotope analysis. Results shows that the lead beads are composed of high-purity lead and cast using for 2 semicircle moulds. Furthermore, 11 lead beads are similar in size, chemical composition and casting methods. Lead isotope analysis data suggest that the provenance of lead beads are not Korea peninsula. Also it is estimated that 11 lead beads were divided in 2 groups considering the time and places of production. The future works will be executed additional scientific analysis and historical background due to confirm the manufacturing system and provenance.

• The monthly packaging world
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• s.67
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• pp.110-111
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• 1998

• Journal of The Korean Association of Information Education
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• v.18 no.1
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• pp.185-193
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• 2014

Software developing education teaches students computer programming, which allows them to actively use IT and talk to computers. In this study, we analyzed computer science curriculum in the United Kingdom, the United States, India, and Estonia. In order to teach 1st - 9th grade students computer programming, we suggested the learning objectives, instructional design, and evaluation methods in software developing education focusing on Information Science. The objectives were divided into four phases, which were determined by age and grade level. Then, we determined 2-3 outcomes for each phase.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.39-48
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• 2014

This thesis suggests a methodology of video editing education that is a part of post-production process. The methodology is educating students on contents, theories, technology in phases according to the characteristics of each process. It is based on the training results from the class 'Understanding of Video Contents Production Technology' conducted for high school students between December, 2013 and August, 2014. The result of the satisfaction survey by enrolled students indicated that high educational satisfaction can be obtained by the education methodology.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.29 no.1
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• pp.25-34
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• 2020

In recent years, as a burden on tooth preparationduring the processing the laminate veneer treatments to enhance aesthetics, the interests and demands for non-prep laminate veneers are increasing which do not require teeth preparation. Although there are clear limitationsbecause the restorations are fabricated without tooth preparation, there is a clear advantage of non-invasivehealthy teeth. When manufacturing a non-prep laminate veneer, an effective design should be selected according to the aesthetic requirements and intraoral condition because the margin of restorationsshould be determined on the natural tooth surface that isnot prepared. In this article, I would like to presentthe three different designsaccording to the range which teeth are covered, and the advantages and disadvantages of them. Non-prep laminate veneer introduced in this article was fabricated using Lithium disilicate press ingot.

• Archives of design research
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• v.17 no.2
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• pp.87-94
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• 2004

3D character animation uses the various entertainment factors such as movie, advertisement, game and cyber idol and occupies an important position in video industry. Although character animation makes various productions and real expressions possible, it is difficult to make character like human body without anatomical understanding of human body. Human body anatomy is the basic knowledge which analyzes physical structure anatomically, gives a lot of helps to make character modeling and make physical movement and facial expression delicately when character animation is produced. Therefore this study examines structure and proportion of human body and focuses on character modeling and animation production based on anatomical understanding of human body.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1976-1978
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• 2002

micro CPL 제작을 위한 LICA 및 MEMS 공정을 개발하였으며 양산화를 위한 새로운 방법으로 ${\mu}$MIM(micro Metal Injection Molding) 기술을 제안하였다. 먼저 LIGA 기술을 이용하여 Cu 도금 구조물로 이루어진 micro CPL 구조물을 제작하였다. 각각 상판과 하판 구조물로 나누어 제작하였으며 상, 하판 Cu 구조물을 brazing 방법을 이용하여 접합하였다. 또한 micro CPL 내부에서 일어나는 냉매의 흐름 및 상변화(liquid ${\leftrightarrow}$ vapor) 거동을 관찰할 수 있는 새로운 개념의 Si/glass 투명 micro CPL을 제작하였다. 상기 공정을 이용하여 냉각 능력이 10w/$cm^2$ 이상인 micro CPL을 제작하였다. 상기 연구 결과를 바탕으로 양산화를 위한 새로운 정밀복제기술인 ${\mu}$MIM(Micro Metal Injection Molding) 공정을 개발하였다. LISA 공정으로 제작된 정밀 금형을 core금형으로 사용하였고 $1{\mu}m$ 이하의 W-Cu(10%) powder와 binder가 혼합된 흔합분말을 이용하여 micro channel 구조물(선폭 $100{\mu}m$)의 성형 복제에 성공함으로서 양산화를 향한 기반기술을 확립하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.92-92
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• 1999

양자우물 무질서화 기술은 양자우물구조의 성장후 그 구조의 밴드갭을 국부적으로 변화시킬 수 있는 기술적 특성으로 인해 기존의 광기능 소자 제작을 위한 결정재성장방법을 대체 혹은 보완할 수 있는 장점이 있기 때문에 최근 활발히 연구되고 있다. 여러 가지 양자우물 무질서화공정중 유전체 박막을 사용하는 impurity free vacancy disordering (IFVD) 공정은 불순물이 개입하지 않는 공정으로 공정후 양질의 반도체 표면을 유지할 수 있는 장점이 있으며 고아소자 제작시 광손실의 증가를 초래하지 않는다. 이 공정은 vacancy의 source로 작용하는 유전체박막의 특성에 크게 의존하며 GaAs/AlGaAs 계열의 양자우물에서는 많은 연구가 진행되었으나, 광통신용 광소자의 제작에 사용되는 InGaAs/InGaAsP 계열의 양자우물에 대한 연구는 충분하지 않다. 그림 1은 IFVD를 위해 본 연구에서 사용된 CBE로 성장한 InGaAs/InGaAsP SQW 구조이다. 성장된 구조는 상온에서의 QW peak, λpl=1550nm 이었다. IFVD를 위한 유전체 덮개층으로는 PECVD로 성장 조정하여 박막성장시의 조건을 변화시킴으로써 유전체 덮개층 박막의 특성을 변화시켰다. 그림 2는 질소 분위기의 furnace에서 75$0^{\circ}C$로 8분간 IFVD를 수행한후 측정한 무질서화된 양자우물의 상온 PL spectrum을 보여준다. 그림에서 보는바와 같이 동일한 SiNx 덮개층을 사용하는 경우에도 적어도 24meV의 bandgap차를 갖는 양자우물을 영역을 동일한 기판상에 제작할 수 있음을 알 수 있다. 일반적으로 IFVD 방법으로 국부적으로 양자우물을 무질서화 하기 위해서는 SiNx/SiO2와 같은 강이한 박막을 사용하였지만 이 방법을 사용하는 경우 상이한 박막을 사용하는 데서 야기되는 제반 문제를 해결할 수 있을 것으로 판단된다. 따라서 이 기술은 기존의 광소자 제작을 위한 IFVD 방법의 문제점을 해결할 뿐만 아니라 결정 재성장 없이 도일한 기판상에 국부적으로 상이한 bandgap 영역을 만들 수 있기 때문에 광소자 제작에 적극 이용될 수 있다.