• 제목/요약/키워드: couplings

검색결과 236건 처리시간 0.024초

An Analytical Framework for a Technological Innovation System: the Case of a Nuclear Power System

  • Lee, Tae Joon;Lee, Young-Joon
    • Asian Journal of Innovation and Policy
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    • 제7권2호
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    • pp.235-286
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    • 2018
  • The aim of paper is to develop an alternative framework for the study of technological innovation systems. In contrast with conventional literature, this analytical framework is designed for entrepreneurs, i.e. actors, at the micro level rather than policy-makers at the meso or macro level. Herein, the entrepreneurial innovation system is conceptually refined by synthesizing knowledge regarding technological innovation and innovation systems. Drawing upon the intrinsic technological identity essential for innovation, the entrepreneurial innovation system is shown to involve three core changes in terms of technology, organization and market, and their couplings within its internal boundary over time. This analytical framework also takes into account the fact that the innovation system is influenced by and copes with the external environment during its evolution. Moreover, the framework of the entrepreneurial innovation system considers the recent trend of sustainable development. The technical and socio-economic characteristics of a nuclear powersystem are studied empirically to articulate an analytical framework that should be very useful for technological innovation in other energy systems by reflecting their unique features.

Application of a new neutronics/thermal-hydraulics coupled code for steady state analysis of light water reactors

  • Safavi, Amir;Esteki, Mohammad Hossein;Mirvakili, Seyed Mohammad;Arani, Mehdi Khaki
    • Nuclear Engineering and Technology
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    • 제52권8호
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    • pp.1603-1610
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    • 2020
  • Due to ever-growing advancements in computers and relatively easy access to them, many efforts have been made to develop high-fidelity, high-performance, multi-physics tools, which play a crucial role in the design and operation of nuclear reactors. For this purpose in this study, the neutronic Monte Carlo and thermal-hydraulic sub-channel codes entitled MCNP and COBRA-EN, respectively, were applied for external coupling with each other. The coupled code was validated by code-to-code comparison with the internal couplings between MCNP5 and SUBCHANFLOW as well as MCNP6 and CTF. The simulation results of all code systems were in good agreement with each other. Then, as the second problem, the core of the VVER-1000 v446 reactor was simulated by the MCNP4C/COBRA-EN coupled code to measure the capability of the developed code to calculate the neutronic and thermohydraulic parameters of real and industrial cases. The simulation results of VVER-1000 core were compared with FSAR and another numerical solution of this benchmark. The obtained results showed that the ability of the MCNP4C/COBRA-EN code for estimating the neutronic and thermohydraulic parameters was very satisfactory.

주역의 색동화와 그 응용을 위한 실험적 연구 (An Experimental Study for Colorizing of I-Ging & Its Usage)

  • 김정희
    • 복식
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    • 제38권
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    • pp.143-157
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    • 1998
  • This research is to aim at presenting arrangement of colors, visual and symbolic through combined coupling ofI-Ging and Sackdong. This combined couplings is attempted to be approached by the following 4 conceptual steps :ⅰ) Is it appropriate to even try to coupleI-Ging with Sackdong\ulcorner ⅱ) Is the basic structure of Kwai an object of stripe colorizing\ulcorner ⅲ) What are the fundamental colors for this purpose\ulcorner ⅳ)combined of Kwai and the fundamental colors. Theoretical background for this study is as follows.ⅰ) Color accord and arrangements of existing Sackdong. ⅱ) An attempt to coupleI-Ging with Sackdong The purpose of this research is to expand concrete concept of Sackdong, which is to be utilized not only in costume design, but in the whole realm of design, by presenting feasible application of stripe coloredI-Ging. The summary of conclusion of this research is as follows. A. Is this aforementioned attempt academic\ulcorner B. Standardization of stripe-coloring is essential. Furthurmore we can conclued that the under-standing ofI-Ging and its basic philosophical background and the fundamental mechanism of colors in traditional costumes is necessary condition for standardization of Kwai. Along this path, however, conditions to be satisfied and priorities to be given depend upon the decision of an individual or a group. In my view, sripe-colorizing of 64 Kwais ofI-Ging followed by intuitive matching of colors with the in-terpretation of Kwais seems to be the most appropriate solution.

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볼트 수 변경에 따른 플랜지 커플링에 대한 구조해석 (Structural Analysis on Flange Coupling due to Change of Bolt Numbers)

  • 한문식;조재웅
    • 한국기계가공학회지
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    • 제12권5호
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    • pp.57-66
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    • 2013
  • This study investigates structural and vibration analyses due to the change of bolt Numbers on models 1 and 2 of flange couplings connected with both sides of axis. As maximum equivalent stresses of models 1 and 2 are 122.05 and 102.3 MPa respectively by the basis of bolt, these stresses are within the allowable stress of this model and the safety of bolt design is verified. As maximum equivalent stresses of models 1 and 2 are 196.2 and 196.4 MPa respectively by the basis of body, these stresses are within the allowable stress of this model and the safety of body design is verified. Through natural frequency analysis, maximum displacements of model 1 and 2 are shown at the frequencies of 6565.1 and 6614.9 Hz respectively. Maximum displacements in cases of models 1 and 2 are shown at harmonic frequencies of 7760 and 7840 Hz at real loading conditions. By putting these study results together, the durability of vibration at model 2 with bolt numbers of 8 becomes better than model 1 with bolt numbers of 6. These study results can be effectively utilized with the design on flange coupling by anticipating and investigating prevention and durability against its damage.

기어-시스템의 동특성에 대한 연구 (A Study on Dynamic Characteristics of Gear-System)

  • 이형우;박노길
    • 한국정밀공학회지
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    • 제22권11호
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    • pp.111-117
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    • 2005
  • The vibration problems associated with gear coupled rotors have been the focus of much engineering work. These systems are complex and difficult to analyze in that they have the problems associated with conventional rotors plus those additional problems associated with the gear couplings. This paper examines the problems peculiar to the gear mesh. Because of the meshing action of gears, the elasticity of the gear teeth introduces time-varying stiffness coefficients into the governing equations of motion. This means that system response must be thought of in terms of Mathieu-type equations, where multiple-frequency response occur due to the periodic coefficients. The meshing action of the gears also couples the lateral and torsional gear motions. Gear errors, such as tooth profile and spacing errors, produce forces and torque that excite the system at multiple frequencies, some of which are much higher than shaft rotational speed. To investigate how to the time-varying stiffness in the gear teeth and the gear errors act one the dynamic response of the gear coupled rotors, a three-dimensional dynamic model with lateral-tortional oscillation is developed. The harmonic balance technique is employed to solve this mathieu-type problem.

고품질 적층형 인덕터를 이용한 이중 대역 GSM/DCS 대역 분리용 다이플렉서의 설계 및 제작 (Design and fabrication of Diplexer for Dual-band GSM/DCS Application using High-Q Multilayer Inductors)

  • 심성훈;강종윤;최지원;윤영중;윤석진;김현재
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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    • pp.294-298
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    • 2003
  • In this paper, the modeling and design of high-Q multilayer passives have been investigated, and multilayer diplexer for GSM/DCS applications has been designed and fabricated using the passives. To minimize the system, the configuration of a multilayer inductor has involved a square spiral structure. Modeling of a multilayer inductor was performed by the subsystems of distributed components, and using the modeling the optimal structures of the high-Q multilayer inductor could be designed by analyzing parasitics and couplings which affect their frequency characteristics. Multilayer diplexer for GSM/DCS application has been designed and fabricated using LTCC technology. LPF for GSM band had the passband insertion loss of less than 0.55 dB, the return loss of more than 12 dB, and the isolation level of more than 26 dB by locating attenuation pole at 1800 MHz. HPF for DCS band had the passband insertion loss of less than 0.82 dB, the return loss of more than 11 dB, and the isolation level of more than 38 dB by locating attenuation pole at 930 MHz.

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CUS 복합재료 항공기 날개의 에일러론 역전 특성 연구 (A Study on the Aileron Reversal Characteristics of CUS Composite Aircraft Wings)

  • 김근택;송오섭
    • 항공우주기술
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    • 제8권2호
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    • pp.149-159
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    • 2009
  • 본 논문은 Circumferentially Uniform Stiffness (CUS) 형상의 복합재료 얇은 벽 보로 모델링한 항공기 날개의 에일러론 역전 특성에 대해 해석적인 연구를 수행하였다. CUS 복합재료 날개의 에일러론 역전 특성을 연구하기 위해, 신장-비틀림 구조 연성, 날개의 가로세로비, 에일러론 대 날개의 시위비 및 길이비, 초기 받음각, Sweep 각 등을 고려하여야 한다. 얇은 벽 보의 항공기 날개에 대한 보다 더 효과적인 설계를 위해, 에일러론 역전 특성과 관련한 연구 결과는 매우 중요한 역할을 담당할 수 있을 것이다.

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A Compact LTCC Dual-Band WLAN Filter using Two Notch Resonators

  • Park, Jun-Hwan;Cheon, Seong-Jong;Park, Jae-Yeong
    • Journal of Electrical Engineering and Technology
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    • 제8권1호
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    • pp.168-175
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    • 2013
  • This paper presents compact dual-band WLAN filter and filter module. They were developed by embedding all of the passive lumped elements into a LTCC substrate. In order to reduce the size/volume of the filter and avoid EM parasitic couplings between the passive elements, the proposed filter was designed using a 3rd order Chebyshev circuit topology and J-inverter transformation technology. The 3rd order Chebyshev bandpass filter was firstly designed for the band-selection of the 802.11b and was then transformed using finite transmission zeros technologies. Finally, the dual-band filter was realized by adding two notch resonators to the 802.11b filter circuit for the band-selection of the 802.11a/g. The maximum insertion losses in the lower and higher passbands were better than 2.0 and 1.3 dB with minimum return losses of 15 and 14 dB, respectively. Furthermore, the filter was integrated with a diplexer to clearly split the signals between 2 and 5 GHz. The maximum insertion and minimum return losses of the fabricated module were 2.2 and 14 dB at 2.4 - 2.5 GHz, and 1.6 and 19 dB at 5.15 - 5.85 GHz, respectively. The overall volume of the fabricated filter was $2.7{\times}2.3{\times}0.59mm^3$.

CAS 복합재료 항공기 날개의 에일러론 역전 특성 연구 (A Study on the Aileron Reversal Characteristics of CAS Composite Aircraft Wings)

  • 송오섭;김근택
    • 한국항공우주학회지
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    • 제37권12호
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    • pp.1192-1200
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    • 2009
  • 본 논문에서는 굽힘-비틀림 연성운동이 일어나는 CAS 형태의 이방성 복합재료 항공기 날개의 에일러론 역전 특성에 관한 해석적인 연구를 수행하였다. 복합재료 날개는 박판보로 모델링되었다. 복합재료 날개의 에일러론 역전 특성에 관한 연구에서, 횡전단변형 및 와핑구속, 굽힘-비틀림 연성, 후퇴각, 날개의 가로세로비, 날개와 에일러론의 길이비 및 시위비, 등을 고려하는 것이 필요하다. 얇은 벽 보의 항공기 날개에 대한 보다 더 효과적인 설계를 위해, 에일러론 역전 특성과 관련한 연구 결과는 매우 중요한 역할을 담당할 수 있을 것이다.

Accurate Measurements of the Unloaded Q of a Dielectric-loaded High-Q $TE_{01{\delta}}$ mode Cavity Resonator with HTS Endplates

  • Kwon, H.J.;Hur, Jung;Lee, Sang-Young
    • Progress in Superconductivity
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    • 제1권1호
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    • pp.36-41
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    • 1999
  • Methods for mode identification and accurate measurements of the unloaded Q ($Q_0$) of a dielectric-loaded $TE_{01{\delta}}$ mode cavity resonator with HTS endplates are proposed. A resonator with a sapphire rod and $YBa_2Cu_3O_{7-x}$(YBCO) endplates was prepared and its microwave properties were studied at temperatures above 30 K. The $TE_{01{\delta}}$ mode $Q_0$ of the resonator, designed to work as a tunable resonator with variations in the gap distance (s) between the sapphire rod and the top YBCO, was more than 1000000 at s = 0 mm and at 30 K with the resonant frequency of 19.56 GHz. The $TE_{01{\delta}}$ mode $Q_0$ decreases as s increases for s < 2 mm until mode couplings between the $TE_{01{\delta}}$ mode and other modes appeared at s = 2 mm. Significant dependence of the $TE_{01{\delta}}$ mode $Q_0$ on the input and output coupling constants was also observed. Applications of the open-ended $TE_{01{\delta}}$ mode cavity resonator for a tunable resonator with a very high Q as well as a characterization tool for the surface resistance measurements of HTS films are described.

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