• 제목/요약/키워드: dual theory

검색결과 340건 처리시간 0.032초

300W급 이중 공극 구조 PMSM 설계 및 출력 특성에 관한 연구 (A Study on Output and Design of Permanent Magnet Synchronous Motor with Dual-gap)

  • 김승주;김윤환;최한석;문재원
    • 조명전기설비학회논문지
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    • 제28권4호
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    • pp.80-87
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    • 2014
  • This paper suggests the dual-gap for generating power and increasing the torque of a direct-drive permanent magnet synchronous motor in a hybrid-cycle. To consider easy coil winding, we applied a structure of dual-gap for the permanent magnet synchronous motor (PMSM). Because the torque of PMSM with the dual-gap is very large, we are designed the appropriate specifications of the PMSM by selected the appropriate dual-gap slot and poles combination. The prototype model is selected by design theory for increasing torque and maximizing output power of PMSM. And the detailed structure design of the model was designed by the loading distribution method. The PMSM models were analyzed by finite element method. Finally, we have suggested appropriate rotor structure has benefit to further increasing torque and prevent decreasing of the output power in PMSM with dual-gap.

ON TOR-TORSION THEORIES

  • GOLRIZ M.;BIJANZADEH M. H.
    • 대한수학회논문집
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    • 제20권2호
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    • pp.209-219
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    • 2005
  • Tor-torsion theory was defined by Jan Trlifaj in 2000. In this paper we introduce the notion of Co envelopes, CoCovers and Tor-generators as dual of envelopes, covers and generators in cotorsion(Ext-torsion) theory and deduce that each R-module has a projective and a cotorsion coprecover.

The Limit of Gene-Culture Co-evolutionary Theory

  • Lee, Min-seop;Jang, Dayk
    • 인지과학
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    • 제28권3호
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    • pp.173-191
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    • 2017
  • The theories of cultural evolution hold subtly or clearly different stances about definition of culture, pattern of cultural evolution, biases that affect cultural evolution, and relationship between culture and organism. However, the cultural evolution theories have a common problem to solve: As the evolutionary theory of life tries to explain the early steps and the origin of life, the cultural evolution theories also must explain the early steps of the cultural evolution and the role of the human capability that makes cultural evolution possible. Therefore, explanations of the human's unique traits including the cultural ability are related to determine which one is the most plausible among many cultural evolution theories. Theories that tried to explain human uniqueness commonly depict the coevolution of gene (organism) and culture. We will explicitly call the niche construction theory and the dual inheritance theory the 'gene-culture co-evolutionary theory'. In these theories, the most important concept is the 'concept of positive feedback'. In this paper, we distinguish between core positive feedback and marginal positive feedback, according to whether the trait that the concept of positive feedback explains is the trait of human uniqueness. Both types of positive feedback effectively explain the generality of human uniqueness and the diversity of human traits driven by cultural groups. However, this positive feedback requires an end, in contrast to negative feedback which can be continued in order to maintain homeostasis. We argue that the co-evolutionary process in the gene-culture co-evolutionary theories include only the positive feedback, not covering the cultural evolution after the positive feedback. This thesis strives to define the coevolution concept more comprehensively by suggesting the potential relationships between gene and culture after the positive feedback.

A Simple Dual-Antenna Diversity Gain Measurement System at 2.4GHz

  • Kim, Jin-Gyong;Chung, Kyung-Ho;Ho, Yo-Choul;Kim, Moon-Il
    • 전기전자학회논문지
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    • 제13권2호
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    • pp.220-223
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    • 2009
  • A simple measurement system is built to estimate the dual-antenna diversity gain at 2.4GHz easily in open lab environment. To obtain multipath fading propagation channel, the system consists of two transmission horn that placed on opposite direction and a rotating stage mechanically changing the position of test dual-antenna with time over distance greater than one wavelength. Estimated diversity is nearly same as theoretical value such that measured diversity gain of 30mm separated is about 6dB similar to theoretical value of 5.7dB and increases monotonically with the increasing separation distance as predicted by the theory. Proposed measurement system that is simple enough to fit in a small space can evaluate the performance of various dual-antennas with a reasonable accuracy with lower 5% difference between the ten sets of measured waveform distribution and theoretical Rayleigh cumulative distribution.

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XPIC를 이용한 ITS/DSRC 주파수 재사용 기법 (ITS/DSRC Frequency Reuse Method using XPIC)

  • 양완철;강경구;이병섭
    • 한국전자파학회논문지
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    • 제13권9호
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    • pp.916-923
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    • 2002
  • 본 논문에서는 ITS/DSRC시스템에서 동일 대역을 유지하면서 시스템 용량을 두 배로 증가시킬 수 있는 방법으로 이중편파(dual-polarization)기법을 제안한다. 이중편파기법은 상호 직교하는 전자기파를 이용하여 정보를 전달하는 방식으로 이론적으로 시스템 용량을 배가시킬 수 있다. 그러나 실제로는 XPl(Cross Polarization Interference)와 다중경로 간섭 등의 요인으로 시스템 성능 열화가 발생하는데 XPI 및 다중경로 간섭을 동시에 제거 가능한 XPIC(Cross Polarization Interference Canceller)를 해결책으로 제시하고 컴퓨터 시뮬레이션을 통해 이를 검증한다

모드정합법을 이용한 20GHz 저손실 이중모드 채널여파기 (A 20 GHz low-loss dual - mode channel filter using mode matching method)

  • 정근욱;이재현;유경완;강성춘
    • 전자공학회논문지D
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    • 제34D권10호
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    • pp.53-59
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    • 1997
  • In this paper, we present a 20 GHz low-loss dual-mode channel filter designed by using mode matching method. The performance of dual-mode channel filter mainly depends on iris characteristics. Therefore the exact design of iris is the key point to get good frequncy response of the filter. MOde matching technique is widely used ot design several kinds of waveguide filters because it is simple in theory and can easily calculate the scattering matrices at the discontinuities with simple structure like iris coupled filters. Additionally the effect for finite thickness of the iris in the dual-mode cavity iflter is analyzed by te full-wave method, providing the exact filter implementation without trial and error.

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Matching Element Sensitivity Analysis for the Operation of a Dual-band Power Amplifier with CRLH Transmission Lines

  • Lee, Byeonguk;Kim, Changwook;Park, Youngcheol
    • 전기전자학회논문지
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    • 제22권4호
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    • pp.1050-1055
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    • 2018
  • In this paper, we analyzed the sensitivity of matching elements for the dual-band operation of a power amplifier with composite right/left-handed (CRLH) transmission lines. Metamaterial theory enables CRLH transmission to support arbitrary impedance matching at dual frequencies. In general, at sub-GHz range, the CRLH matching networks are commonly implemented with lumped elements, which are prone to manufacturing distribution. In order to reduce the effect from the distribution of element values in design, we suggest a method to analyze the sensitivity of matching elements from the performance aspect of power amplifiers. Based on the analysis, a 40dBm dual-band power amplifier operating at 0.7GHz and 1.5GHz is designed.

DIRECT SUM, SEPARATING SET AND SYSTEMS OF SIMULTANEOUS EQUATIONS IN THE PREDUAL OF AN OPERATOR ALGEBRA

  • Lee, Mi-Young;Lee, Sang-Hun
    • 대한수학회보
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    • 제31권2호
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    • pp.173-180
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    • 1994
  • Let H be a separable, infinite dimensional, compled Hilbert space and let L(H) be the algebra of all bounded linear operators on H. A dual algebra is a subalgebra of L(H) that contains the identity operator $I_{H}$ and is closed in the ultraweak topology on L(H). Note that the ultraweak operator topology coincides with the wea $k^{*}$ topology on L(H)(see [3]). Bercovici-Foias-Pearcy [3] studied the problem of solving systems of simultaneous equations in the predual of a dual algebra. The theory of dual algebras has been applied to the topics of invariant subspaces, dilation theory and reflexibity (see [1],[2],[3],[5],[6]), and is deeply related with properties ( $A_{m,n}$). Jung-Lee-Lee [7] introduced n-separating sets for subalgebras and proved the relationship between n-separating sets and properties ( $A_{m,n}$). In this paper we will study the relationship between direct sum and properties ( $A_{m,n}$). In particular, using some results of [7] we obtain relationship between n-separating sets and direct sum of von Neumann algebras.ras.s.ras.

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Tri-band Microstrip Bandpass Filter Using Dual-Mode Stepped-Impedance Resonator

  • Liu, Haiwen;Lei, Jiuhuai;Zhao, Yulong;Xu, Wenyuan;Fan, Yichao;Wu, Tiantian
    • ETRI Journal
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    • 제35권2호
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    • pp.344-347
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    • 2013
  • This letter presents a compact dual-mode tri-band bandpass filter by using a short-circuited stub-loaded stepped-impedance resonator (SIR) and a short-circuited stub-loaded uniform impedance resonator. Also, a hairpin SIR geometry is introduced to miniature the size of this filter while maintaining excellent performance. The use of a short-circuited stub at the central point of the hairpin SIR can generate two resonant modes in two passbands. Its equivalent circuit structure is analyzed by using the even-odd mode theory. For demonstration purposes, a tri-band filter for the applications of the Global Positioning System at 1.57 GHz, Worldwide Interoperability for Microwave Access at 3.5 GHz, and wireless local area networks at 5.2 GHz is designed, fabricated, and measured.

음양오행에 기반한 캐릭터 걷기 동작 분석 (Analysis on the Walking Motion of the Animation Characters Based on the Cosmic Dual Forces and the Five Elements Theory)

  • 이미영;김재호;문용호
    • 디자인학연구
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    • 제19권2호
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    • pp.355-364
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    • 2006
  • 애니메이션에서 등장하는 캐릭터들은 다양한 외형적인 모습과 성격들을 소유하고 있다. 이러한 개성과 성격들은 일반적으로 형태, 행동, 대화, 걷기 동작 등과 같은 다양한 요소들에 의해 표현된다. 특히, 걷기 동작은 캐릭터의 움직임 표현에 있어 가장 기본적인 요소이면서 캐릭터의 개성표현에 중요한 부분을 차지한다. 본 연구에서는 캐릭터의 특징이 잘 표현된 애니메이션들을 중심으로 음양오행이론을 접목하여 외형적 모습과 성격에 따라 캐릭터들을 분류한다. 그리고 분류한 캐릭터들의 동작을 분석함으로써 캐릭터의 개성과 움직임간의 관계를 제시한다.

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