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Measurement of ion-induced secondary electron emission coefficient for MgO thin film with $O_{2}$ plasma treatment

  • Jeong, H.S.;Oh, J.S.;Lim, J.Y.;Cho, J.W.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.802-805
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    • 2003
  • The ion-induced secondary electron emission coefficient ${\gamma}$ for MgO thin film with $O_{2}$ plasma treatment has been investigated by ${\gamma}$-FIB (focused ion beam) system. The MgO thin film deposited from sintered material with $O_2$ plasma treatment is found to have higher ${\gamma}$ than that without $O_{2}$ plasma treatment. The energy of $Ne^{+}$ ions used has been ranged from 100eV to 200eV throughout this experiment. It is found that the highest secondary electron emission coefficient ${\gamma}$ has been achieved for 10 minutes of $O_{2}$ plasma treatment.

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Taxoids, Lignans, and Simple Phenolic Compounds from a Sample of the Needles of Himalayan Taxus baccata

  • Das, Biswanath;Anjani, G.;Kashinatham, A.;Venkataiah, B.;Rao, S. Padma
    • Natural Product Sciences
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    • v.4 no.2
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    • pp.78-83
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    • 1998
  • Chemical investigation on a sample of the needles of Himalayan Taxus baccata has resulted in the isolation of several taxoids including taxol (1) 10-deacetyl-baccatin III (2) and 2-deacetoxytaxinine J (3) along with different lignans (6 and 7) and simple phenolics (8, 9, 10, 11 and 12). The occurrence of 4-(4'-hydroxyphenyl)-butane-2-one and 4-(4'-hydroxyphenyl)-trans-but 3-ene-2-one (8) in Taxus species is reported for the first time. The $^{13}C-NMR$ spectral data of two rearranged taxiod constituents, brevifoliol (4) and 13-decinnamoyltaxchinin B (5) are presented. The acid-catalyzed decomposition of taxol has been discussed. The synthesis of other two constituents, rhododendrol (10) and hibalactone (7) has been described.

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The formation of Mn-ferrite by electrolysis (전해법에 의한 Mn-ferrite 생성)

  • 김유상;황용길
    • Journal of Surface Science and Engineering
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    • v.24 no.1
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    • pp.1.2-1.2
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    • 1991
  • The formation of managanese ferrite has been performed to investigate some properties according to the variation of compositions, pH, current density by electrolysis. It has been found that the amount of oxidized weight of anode were increased with increasing current density. The amount of oxidized weight of anode were most in pH10. As the result of X-ray diffraction Mn Fe2O4 crystal composition in pH13. When the particles of Mnx Fe3-x O4 were heated at 30$0^{\circ}C$, it has been shown typical MnFe2O4(JCPDS Card No. 10-319) in X-1 composition. As the result of SEM observation, the size of MnFe2O4 particles were about 0.1$\mu\textrm{m}$, the shape of particles were spherical type. According to the above mentioned experimental condition, 0.1-0.5$\mu\textrm{m}$ sub-micron particles of manganese ferrite were formed from the wasted manganese dry cell, through washing longrightarrow reduction longrightarrow electrloysis.

Functional Improvement of Poly(Vinyl Alcohol) Polarized Film by $O_2$ Low Temperature Plasma Treatment (산소 저온 플라즈마 처리에 의한 PVA 편광필름의 기능성 개선)

  • Park, Young-Mi;Hwang, Jong-Ho;Gu, Kang
    • Textile Coloration and Finishing
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    • v.16 no.3
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    • pp.14-21
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    • 2004
  • In this research, we accomplished in order to improving color fastness of sublimation for Poly (vinyl alcohol) (PVA)-iodine polarized film. The poor iodine sublimation problem has greatly improved by $O_2$ low temperature plasma treatment. We obtained the followings: (1) plasma treatment has contributed in adhesive ability via peel strength, AFM image and roughness were investigated, But the improvement in adhesive strength was not linearly proportional to the treatment time. (2) $O_2$ plasma treated PVA-iodine polarized film was good enough as to maintain the transmittance and polarization even after iodine cone. of 0.05mol/L and dipping time of 50sec. (3) $O_2$ low temperature plasma treated PVA-iodine polarized film has obtain high durability because of good adhesive strength.

The Field Coil End Effect of HTS Synchronous Motor (고온초전도 동기모터의 계자코일 단부의 영향)

  • 백승규;권운식;손명환;이언용;권영길
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2003.02a
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    • pp.276-279
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    • 2003
  • The superconducting synchronous machine(S.S.M) including generator and motor has different electromagnetic structure from the conventional machine. With the help of superconductor having much higher operating current density than normal conductor, S.S.M can eliminate most of iron core filling inside of the conventional machine. This air-cored structure could be analysed and designed theoretically based on 2-dimensional(2-D) magnetic field distribution assuming that the windings are extended infinitely toward the axial direction. However the actual structure of S.S.M has the end regions interconnecting the straight parts of the same cross-section with the 2-D model. Therefore, this actual 3-D model has smaller field distribution than the 2-D model. In this paper, we consider the effect of the end regions on the output of a HTS model motor and suggest more accurate design approach through comparison of 2-D and 3-D magnetic field analysis.

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Fabrication of the Hihg Power SiGe Heterojunction Bipolar Transistors using APCVD (상압 화학 기상 증착기를 이용한 고출력 SiGe HBT제작)

  • 한태현;이수민;조덕호;염병령
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.26-28
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    • 1996
  • A high power SiGe HBT has been fabricated using APCVD(Atmospheric Pressure Chemical Vapor Deposition) and its perfermanoe has been analysed. The composition of Ge in the SiGe base was graded from 0% at the emitter-base junction to 20% at the base-collector junction. As a base electrode, titanium disilicide(TiSi$_2$) was used to reduce the extrinsic base resistance. The SiGe HBT with an emitter area of 2$\times$8${\mu}{\textrm}{m}$$^2$typically has a cutoff frequency(f$_{T}$) of 7.0GHz and a maximun oscillation frequency(f$_{max}$) of 16.1GHz with a pad de-embedding. The packaged high power SiGe HBT with an emitter area of 2xBx80${\mu}{\textrm}{m}$$^2$typically shows a cutoff frequency of 4.7GHz and a maximun oscillation frequency of 7.1GHz at Ic of 115mA.A.A.

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Improving Data Input of ECO2-OD Program Utilizing BIM (BIM을 이용한 ECO2-OD 프로그램의 정보입력 개선)

  • Kang, Min-Su;Kim, Ka-Ram;Yu, Jung-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.205-207
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    • 2013
  • In a situation that building energy consumption is increasing worldwide, the research utilizing BIM technology to analyze building energy has been actively conducted. On the other hand, data input method of the building energy analysis has been still manually entered. This paper proposed a improved input method of required information for building energy analysis using the ECO2-OD program. As a result, although some required information of BIM based design software could be almost entered when it comes to general information and architectural sector, it has a problem to be handled in HVAC sector. Therefore, in the both of general and architectural sectors, the BIM information from the BIM-based design software could be directly used to automatically and systematically input the information. Future research should be studied the algorism and method in connection with data exchange to utilize input method of ECO2-OD from BIM data.

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An Optimal Control of Container Crane Using Evolution Strategy (진화전략을 이용한 컨테이너 크레인의 최적제어에 관한 연구)

  • 이영진;이권순
    • Journal of Korean Port Research
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    • v.12 no.2
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    • pp.217-224
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    • 1998
  • During the operation of crane system in container yard, the objective is to transport the load to a goal position as quick as possible without rope oscillation. The container crane is generally operated by an expert operator, but recently an automatic control system with high speed and rapid transportation is required. Therefore, we developed an optimal controller which has to control the crane system with disturbances. In this paper, we present a design of optima 2-DOF PID controller for the control of gantry crane which has to control swing motion and trolley position. We used evolution strategy(ES) to tune the parameters of 2-DOF PID controller. It was compared with general PID controller. The computer simulations show that the proposed method has better performances than the other method.

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Nonlinear Static Analysis of Irregular RC Buildings (비정형 철근콘크리트건물의 비선형 정적해석)

  • Ko, Dong-Woo;Lee, Han-Seon
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.225-232
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    • 2006
  • Three building structures haying piloti frames in the lower two stories were selected as prototypes and were analyzed using nonlinear static analysis to investigate the seismic capacity of these buildings. The first one has a symmetrical moment resisting frame (Model 1), the second has an infilled shear wall in the central frame (Model 2), and the third has an infilled shear wall only in one of exterior frames (Model 3), The analytical results were compared with those of shaking table tests with regards to the overstrength and ductility of the irregular buildings. Infilled shear wall in Model 2 and Model 3 induced large overstrength factors, 6.8 and 6.0, respectively, which are about two times larger than that of Model 1, 3.5. The displacement ductility ratio in Model 2 was only 2.5, due to the shear failure of wall in the piloti stories, whereas those of Model 1 and Model 3 reached 3.2.

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Luminescence Characteristics Of $Gd_2$$O_3$$Eu^3+$/ thin film phosphors by Li-doping (Li 첨가에 의한 $Gd_2$$O_3$$Eu^3+$/ 박막 형광체의 형광 특성)

  • Bae, Jong-Seong;Moon, Byung-Kee;Seo, Hyo-Jin;Jeong, Jung-Hyun;Yi, Soung-soo
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.284-285
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    • 2003
  • Significant research interest in the growth and characterization of $Y_2$O$_3$:Eu$^{3+}$ thin films has been shown over the last few years because of the promise for applications of display devices. Although an Eu-doped oxysulfide (Eu: $Y_2$O$_2$S) which has an efficiency of 13% has been used for a traditional cathode ray tube (CRT) red phosphor, the sulfide system is known to degrade rapidly under the high current densities needed for field-emission display (FED) technology. (omitted)d)

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