• Title/Summary/Keyword: external field

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IT SME Ventures' External Information Network Diversity and Productivity Improvement : The Mediating Role of the Production Period Reduction (IT 중소벤처기업의 외부 정보 네트워크의 다양성과 생산성 향상 : 생산 기간 단축의 매개적 역할)

  • Hau, Yong Sauk
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.1
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    • pp.144-149
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    • 2017
  • This study empirically analyzes the effect of IT SME ventures' external information network diversity on their production period reduction and productivity improvement generated from technology development. This research constructs a mediating model based on the open innovation perspective and tests it with the 138 samples of South Korean IT SME ventures based on the ordinary least squares regression. This research is expected to make a good contribution by shedding a new light on the following three points about the critical role of IT SME ventures' external information network diversity in increasing their production period reduction and productivity improvement generated from technology development which has scarcely been illuminated in the extant studies in the field of the management of technology for SMEs. First, IT SME ventures' external information network diversity positively influences their production period reduction. Second, the external information network diversity positively influences IT SMEs' ventures' productivity improvement. Third, IT SME ventures' production period reduction partially mediates the influence of IT SME ventures' external network diversity on their productivity improvement. These three fresh points are expected to provide useful theoretical and practical implications. Related to the theoretical implication, this research provides a fresh implication that IT SME ventures' external information network diversity positively influences not only their production period reduction but also productivity improvement generated from technology development. Concerning the practical implication, this study suggests that the CEOs in IT SME ventures make strategic efforts to use more diverse external information sources in order to increase their production period reduction and productivity improvement generated from technology development.

A Pathway to Microdomain Alignment in Block Copolymer/Nanoparticle Thin Films under Electric Field

  • Bae, Joonwon
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2689-2693
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    • 2014
  • The control over microstructure in block copolymer thin films using external electric fields has become an interesting research topic. In this article, the effect of nanoparticle on the microdomain alignments in block copolymer (polystyrene-b-poly(2-vinylpyridine)/nanoparticle (Au) thin films under electric fields has been examined with transmission electron microscopy. The homogeneous dispersion of Au nanoparticles into the block copolymer matrix was achieved by surface modification of nanoparticles with compatible ligands. Compared with the phenomenon seen in the pristine block copolymer thin films, a peculiar alignment behavior was observed in the block copolymer/nanoparticle hybrid thin films under electric fields. In addition, the different pathways observed in the pristine and nanoparticle incorporated block copolymer thin films were also monitored as a function of exposure time. This work can provide the fundamental information for understanding microdomain alignment in block copolymer/nanoparticle thin films under external electric fields.

Electric-field induced si-graphene heterostructure solar cell using top gate

  • Won, Ui-Yeon;Yu, U-Jong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.287.2-287.2
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    • 2016
  • Silicon has considerably good characteristics on electron, hole mobility and its price. With 2-D sinlge-layer Graphene/n-Si heterojunction solar cell shows that in one sun condition exhibit power conversion efficiency(PCE) of 10.1%. This photovoltaic effect was achieved by applying gate voltage to the Schottky junction of the heterostructure solar cell. Energy band diagram shows that Schottky barrier between Si and graphene can be adjust by the external electric field. because of the fermi level of the graphene can be changed by external gate voltage, we can control the Schottkky barrier of the heterostructure solar cell. The ratio between generated power of solar cell and consumption electrical power is remarkable. Since we use the graphene as the top gate electrode, most of the sun light can penetrate into the active area.

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Calculation of DC Characteristics of Stacked BSCCO Wires under Variable External Magnetic field (수치해석을 이용한 BSCCO 적층 선제들의 외부자장 변화에 따른 DC 통전 특성 계산)

  • Lim, Hyoung-Woo;Kang, Myung-Hun;Cha, Guee-Soo;Lee, Hee-Joon
    • Proceedings of the KIEE Conference
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    • 2007.10c
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    • pp.53-55
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    • 2007
  • This paper has presented the numerical calculation of fundamental characteristics of the HTS wire by using commercial software. Numerical calculation of the HTS wire's characteristics is able to reduce the time and effort which need to be exerted to obtain hose values experimentally. Results of numerical calculation, such as, critical current of he single and the multi-slacked wire under external magnetic field, were compared with that of experimental results.

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Geophysical Navigation for UUV without External Telemetry Systems (지구 물리정보를 이용한 무인잠수정의 복합 항법 기술)

  • Jang, Junwoo;Cho, Hyunkuen;Kim, Jinwhan;Byun, Seung-Woo
    • The Journal of Korea Robotics Society
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    • v.15 no.1
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    • pp.24-31
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    • 2020
  • Alternative navigation in underwater environments is essential to prevent accumulating drift error of dead reckoning. In case of using an external positioning system, the installation and management process of the transmission station is cumbersome, and the operation range of underwater vehicle is limited. In order to solve this problem, navigation using geophysical information such as terrain, geomagnetic field and gravity can be used. Unlike the terrain, geomagnetic field and gravity are composed of 3-D information, so continuation process is required. In this paper, we present a integrated navigation algorithm using multiple geophysical information for long-term operation of UUV. The proposed algorithm is verified through numerical simulation in an artificially generated environments. As a result, integrated navigation showed higher navigation accuracy than single alternative navigation.

Magnetization Frequency Dependence of Enhanced Inductively Coupled Plasma and Etching Characteristics (자화주파수에 따른 플라즈마 및 산화막식각특성에 관한 연구)

  • 김진우;조수범;박세근;오범환
    • Proceedings of the IEEK Conference
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    • 2001.06b
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    • pp.37-40
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    • 2001
  • The semiconductor's design rule becomes more stringent, hence the silicon-dioxide etching technique is important issue. In this work we compared the etching characteristics of different three types of Plasma source, Normal ICP, magnetized ICP and E-IC $P^{TM}$. The E-IC $P^{TM}$ source shows higher etch rate at lower pressure and this is advantageous for the fine pattern process. The etching characteristics were varied with external magnetic field frequency at I-lCP and this is examined with Nanospe $c^{TM}$ and SEM. We designed Langmuir probe system for time resolved diagnosis. ion density of E-ICP is varying periodically with the applied external magnetic field frequencyquency

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Performance of Gas Electron Multiplier (GEM) detector

  • Han, S.H.;Moon, B.S.;Kim, Y.K.;Chung, C.E.;Kang, H.D.;Cho, H.S.
    • Journal of Radiation Protection and Research
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    • v.28 no.4
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    • pp.343-348
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    • 2003
  • We have investigated in detail the operating properties of Gas Electron Multiplier (GEM) detectors with a double conical and a cylindrical structure in a wide range of external fields and GEM voltages. With the double conical GEM, the gain gradually increased with time by 10%; whereas this surface charging was eliminated with the cylindrical GEM. Effective gains above 1000 were easily observed over a wide range of collection field strengths in a gas mixture of $Ar/CO_2(70/30)$. The transparency and electron collection efficiency were found to depend on the ratio of external field and the applied GEM voltage; the mutual influence of both drift and collection fields was found to be trivial.

Static measurement of magnetostriction of FeCoGe/phenol composites (FeCoGe/페놀 복합체의 정적 자기변형 측정)

  • Park, K.I.;Na, S.M.;Shin, K.H.;Lim, S.H.;SaGong, G.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.577-580
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    • 2003
  • The magnetostriction of FeCoGe/phenol composites, which is one of the magnetostrictive materials, measured at the external magnetic field. The measurement was carried out using the electrical-resistance strain gage, the wheaten's Bridge for eliminating the unnecessary voltage, and the lock-in-amp for signal amplification and noise filtering. When the external magnetic field was applied in the longitudinal the samples, the maximum strain of 120ppm was taken with regard to the 10wt.% phenol composite. This results indicate that the FeCoGe/phenol composites can be useful as an actuator because it has larger stain than the other solid state actuators such as piezo electric materials.

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Analysis of I-V Characteristics in the Multi-channel Superconducting Vortex Flow Transistor (다채널 고온 초전도 볼텍스 유동 트랜지스터의 I-V 특성 해석)

  • 고석철;강형곤;임성훈;최효상;한병성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.10
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    • pp.931-937
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    • 2003
  • The principle of the superconducting vortex flow transistor (SVFT) is based on control of the Abrikosov vortex flowing along a channel. The induced voltage is controlled by a bias current and a control current, instead of external magnetic field. The device is composed of parallel weak links with a nearby current control line. We explained the process to get an I-V characteristic equation and described the method to induce the external and internal magnetic field by the Biot-Savarts law in this paper. The equation can be used to predict the I-V curves for fabricated device. From the equation we demonstrated that the current-voltage characteristics were changed with input parameters. I-V characteristics were simulated to analyze a SVFT with multi-channel by a computer program.

The Performance Analysis of Direct Current Electromagnetic Propulsion in Seawater

  • Kong, Yeong-Kyung;Park, Tai-In;Kim, Yun-Sik;Noh, Chang-Joo
    • Journal of Energy Engineering
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    • v.2 no.1
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    • pp.38-44
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    • 1993
  • Electromagnetic seawater thrusters may be classified into four general categories : internal duct dc, external field dc, internal peristaltic ac, and external peristaltic ac. Internal duct dc thrusters offer the advantages of low magnetic field leakage, simple construction, and potentially high reliability. The most efficient internal duct configuration consists of converging inlet nozzle and a straight discharge duct. Ideal efficiency calculations based on the one-dimensional Bernoulli equation show that thrusters should be designed with large cross-sectional areas and operate at low discharge velocities. In practice, this may be accomplished by using multiple thruster ducts. Conductivity enhancement, high magnetic fields, and long electrodes will also improve efficiency.

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