• 제목/요약/키워드: pencil

검색결과 475건 처리시간 0.023초

Maskless용 스크린 제판 기술 연구(I) (A Study on the Maskless Plate Making Technology for Screen Printing(I))

  • 이미영;박경진;남수용
    • 한국인쇄학회지
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    • 제26권1호
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    • pp.73-85
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    • 2008
  • We have manufactured a photoresist which has excellent dispersity and good applying property due to 330cps of viscosity for environment-friendly and economical maskless screen plate making. And the photoresist applied on the screen stretched was exposed without mask by beam projector with CRT light source. Then it was developed by air spray with $1.7kgf/cm^2$ of injection pressure. The pencil hardness and solvent resistance of curing photoresist film were worse than those of conventional photoresist film and the maximum resolution of line image formed by maskless screen plate making was 0.5 mm since the exposure system for maskless plate making has weak light intensity and the diffusion of light. But we could obtain maskless screen plate which has sharp edges of line image and confirm a possibility of dry development process by air spray method.

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Diagnostic Assay of Phenol Ions in Human Tissue

  • Ly, Suw-Young;Lee, Jin-Hui;Yoo, So-Dam;Hong, Ki-Won;Lee, Kyu-Jung
    • 한국응용과학기술학회지
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    • 제28권4호
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    • pp.502-507
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    • 2011
  • A voltammetric assay of phenol ions was investigated using three electrode systems of graphite pencil working, reference and counter electrodes. Under optimum analytical parameters, square wave stripping working ranges were attained at a mili range of 10~80 mg/L and a micro range of 20~90 ug/L using seawater electrolyte. The developed sensor was applied to tap water and the human body system of a smoker. It was found that the methods can be applied to in vivo fluid or medicinal diagnosis.

능동회로에서의 노이즈 규명 및 MPM기법을 통한 저감 (Noise identification on active circuits and reduction using MPM technique)

  • 오경석;이종복;고일관;허춘
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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    • pp.3063-3065
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    • 2005
  • In the raper, the noise involved on the active circuit is identified using correlation function. In order to identify the unknown noise source location, signals from each points on the system are detected and the location is identified by a concept calico Noise Source Surface. The fault diagnosis method is suggested for each element by identifying the noise source in active circuit using SVM. Experiment is conducted to confirm the validity of the proposed method. Also a method to reduce and control the noise in the system signal by using Matrix Pencil Method is introduced.

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자체적으로 진공을 갖는 수평형 전계 방출 트라이오드 (A novel in-situ vacuu encapsulted lateral field emitter triode)

  • 임무섭;박철민;한민구;최연익
    • 전자공학회논문지A
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    • 제33A권12호
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    • pp.65-71
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    • 1996
  • A novel lateral field emitter triode has been designed and fabricated. It has self-vacuum environmets and low turn-on voltage, so that the chief problems of previous field emission devices such as additional vacuum sealing process and high turn-on voltage are settled. An in-situ vaccum encapsulation empolying recessed cavities by isotropic RIE (reactive ion etch) method and an electron beam evaporated molybdenum vacuum seals are implemented to fabricate the new field emitter triode. The device exhibits low turn-on voltage of 7V, stabel current density of 2.mu.A/tip at V$_{AC}$ = 30V, and high transconductance (g$_{m}$) of 1.7$\mu$S at V$_{AC}$ = 22V. The superb device characteristics are probably due to sub-micron dimension device structure and the pencil type lateral cathode tip employing upper and lower LOCOS oxidation.

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Factors Affecting Earth Science Problem-Solving Performances of Elementary School Pre-service Teachers: A Study on the Motions of the Moon and the Planets

  • Myeong, Jeon-Ok
    • 한국지구과학회지
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    • 제23권2호
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    • pp.180-187
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    • 2002
  • The aim of this study was to investigate the factors affecting earth science problem-solving performances of elementary school pre-service teachers. The participants of the study were 81 students attending an elementary school teacher education university. The instruments of the study were paper-and-pencil tests, questionnaires, and interviews. The tests mainly measured the participants' problem solving abilities in the motions of the moon and the planets. Correlation and multiple regression techniques were used for data analysis. The results demonstrated that the pre-service teachers' problem solving abilities were low. Problem-solving performances were affected by the procedural knowledge, the participants' perception of the past earth science performance, self-efficacy, and the prerequisite declarative knowledge. Contrary to our expectation, the spatial visualization ability was not found to be related to the problem-solving performances. Implications of the study are drawn, and suggestions are made for further research.

Synthesis of Hybrid Sol Based on ZrO2-SiO2 System and their Coating Properties

  • Lee, Sang-Hoon;Park, Won-Kyu
    • 한국세라믹학회지
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    • 제41권5호
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    • pp.349-352
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    • 2004
  • Organic-inorganic hybrid sol based on ZrO$_2$-SiO$_2$ system was prepared by sol-gel process. Firstly, ZrO$_2$ non-aqueous precursor sol was synthesized and then organosilane compounds which include epoxy silane (GPTS; 3-g1ycidoxypropyl tri-methoxysilane) and acryl silane (ACS; (3-(tri-methoxysilyl)propylmethacrylate)) were added to ZrO$_2$precursor sol for hybridization. Finally, com-mercial silica sol was added to improve the mechanical properties. Synthesized organic-inorganic Zr-hybrid sol was coated on polycarbonate substrate for enhancing it’s mechanical properties, especially hardness. Vicker’s hardness of polycarbonate sub strate was increased from 13.6 to 17.8 MPa and its pencil hardness was increased from 2 to 7 H, respectively, after coating and drying at 10$0^{\circ}C$ for 30 min.

웹 기반 협동학습이 정신지체 아동의 사회적 능력 신장에 미치는 효과 (An Effects on Web-based Cooperative Learning to Enhance Social Adaptability to in the Students with Mental Retardation Children)

  • 엄경민;인치호
    • 정보학연구
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    • 제12권4호
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    • pp.33-37
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    • 2009
  • This paper analyzed effects Web-Based cooperation Learning have on improvement in Social Adaptability and problematic behavior, using Web-Based cooperation Learning system that is designed for Mental retardation children. Is Made Teaching Design according to students level, based on elementary school Bareunsaenghwal subject. Teaching and Learning program that is going with flash and PPT Embodied is. Designed to bulletin the evaluation data for cooperation studying after studying a part of the lesson. Verification of learning effect went with experimental group and comparison group consisted of groups of 8. Students studied the Internet web data and Teaching material paper and they took pencil test. As a result, point of post-inspection was higher than that of pre-inspection. Web-Based cooperation Learning is confirmed to be effective on Social Adaptability and problematic behavior improvement.

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On the Education of Talented Children for the Creativity Development by Using CAS

  • Takahashi, Tadashi
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제13권1호
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    • pp.1-4
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    • 2009
  • We are considering the discovery and the promotion of the talent from the viewpoint of education of talented children. The education that develops the talent is from "Individual needs for all children." Computer Algebra System (CAS) can be used as a new possibility in the education that develops the talent. We will need to take advantage of the research results from cognitive science. In order to fully utilize CASs in education, teaching methods that are based on cognitive science will be needed, and these are clearly different from those used in paper and pencil teaching.

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Toxicological Investigation of Radioactive Uranium in Seawater

  • Ly, Suw-Young;Bae, Jeong-Mi;Kim, Jin
    • Toxicological Research
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    • 제28권1호
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    • pp.67-71
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    • 2012
  • Trace uranium detection measurement was performed using DNA immobilized on a graphite pencil electrode(DGE). The developed probe was connected to the portable handheld voltammetric systems used for seawater analysis. The sensitive voltammogram was obtained within only 30 s accumulation time, and the anodic stripping working range was attained at 100~800 ${\mu}g/l$ U and 10~50 ${\mu}g/l$. The statistic relative standard deviation of 30.0 mg/l with the $15^{th}$ stripping was 0.2115. Here, toxicological and analytical application was performed in the seawater survey in a contaminated power plant controlling water. The results were found to be applicable for real-time toxicological assay for trace control.

초등수학 학습에 있어서 표상에 관한 고찰 (A Study on the Representation of Elementary Mathematics Learning)

  • 최창우
    • 한국수학교육학회지시리즈C:초등수학교육
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    • 제8권1호
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    • pp.23-32
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    • 2004
  • It is not too much to say that problem solving is still the focus of school mathematics though the trend of mathematics education for ten year from the one of 1980 is problem solving and the one of mathematics education for ten year from the one of 1990 is standards and constructivism. There are so many crucial clues or methods in good problem solving but I think that one of them is a representation. So, the purpose of this study is to investigate what is the meaning of representation in general and why representation is so important in elementary mathematics learning, Moreover, I have analyzed the gifted children's thinking of representation which is appeared in the previous internet home task of 40 gifted children who are selected through the examination of 1st, 2nd with paper and pencil and 3rd with practical skill and interview and finally I have presented some examples of children's representation how they use representation to model, investigate and understand special concept more easily in elementary school mathematics class.

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