• Title/Summary/Keyword: Complex vector

검색결과 616건 처리시간 0.023초

WEIGHTED ESTIMATES FOR CERTAIN ROUGH OPERATORS WITH APPLICATIONS TO VECTOR VALUED INEQUALITIES

  • Liu, Feng;Xue, Qingying
    • 대한수학회지
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    • 제58권4호
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    • pp.1035-1058
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    • 2021

  • Under certain rather weak size conditions assumed on the kernels, some weighted norm inequalities for singular integral operators, related maximal operators, maximal truncated singular integral operators and Marcinkiewicz integral operators in nonisotropic setting will be shown. These weighted norm inequalities will enable us to obtain some vector valued inequalities for the above operators.

  • https://doi.org/10.4134/JKMS.j200450 인용 PDF KSCI

Efficient Hybrid Carrier Based Space Vector Modulation for a Cascaded Multilevel Inverter

  • Govindaraju, C.;Baskaran, K.
    • Journal of Power Electronics
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    • 제10권3호
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    • pp.277-284
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    • 2010

  • This paper presents a novel hybrid carrier based space vector modulation for cascaded multilevel inverters. The proposed technique inherits the properties of carrier based space vector modulation and the fundamental frequency modulation strategy. The main characteristic of this modulation are the reduction of power loss, and improved harmonic performance. The carrier based space vector modulation algorithm is implemented with a TMS320F2407 digital signal processor. A Xilinx Complex Programmable Logic Device is used to develop the hybrid PWM control algorithm and it is integrated with a digital signal processor for hybrid carrier based space vector PWM generation. The inverter offers less weighted total harmonic distortion and it operates with equal electrostatic and electromagnetic stress among the power devices. The feasibility of the proposed technique is verified by spectral analysis, simulation, and experimental results.

  • https://doi.org/10.6113/JPE.2010.10.3.277 인용 PDF KSCI

A PROPERTY OF COFUNCTORS SF(X,A)

  • So, Kwang Ho
    • Kyungpook Mathematical Journal
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    • 제13권2호
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    • pp.235-240
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    • 1973

  • A k-dimensional vector bundle is a bundle ${\xi}=(E,P,B,F^k)$ with fibre $F^k$ satisfying the local triviality, where F is the field of real numbers R or complex numbers C ([1], [2] and [3]). Let $Vect_k(X)$ be the set consisting of all isomorphism classes of k-dimensional vector bundles over the topological space X. Then $Vect_F(X)=\{Vect_k(X)\}_{k=0,1,{\cdots}}$ is a semigroup with Whitney sum (${\S}1$). For a pair (X, A) of topological spaces, a difference isomorphism over (X, A) is a vector bundle morphism ([2], [3]) ${\alpha}:{\xi}_0{\rightarrow}{\xi}_1$ such that the restriction ${\alpha}:{\xi}_0{\mid}A{\longrightarrow}{\xi}_1{\mid}A$ is an isomorphism. Let $S_k(X,A)$ be the set of all difference isomorphism classes over (X, A) of k-dimensional vector bundles over X with fibre $F^k$. Then $S_F(X,A)=\{S_k(X,A)\}_{k=0,1,{\cdots}}$, is a semigroup with Whitney Sum (${\S}2$). In this paper, we shall prove a relation between $Vect_F(X)$ and $S_F(X,A)$ under some conditions (Theorem 2, which is the main theorem of this paper). We shall use the following theorem in the paper. THEOREM 1. Let ${\xi}=(E,P,B)$ be a locally trivial bundle with fibre F, where (B, A) is a relative CW-complex. Then all cross sections S of ${\xi}{\mid}A$ prolong to a cross section $S^*$ of ${\xi}$ under either of the following hypothesis: (H1) The space F is (m-1)-connected for each $m{\leq}dim$ B. (H2) There is a relative CW-complex (Y, X) such that $B=Y{\times}I$ and $A=(X{\times}I)$ ${\cap}(Y{\times}O)$, where I=[0, 1]. (For proof see p.21 [2]).

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인터넷을 통한 벡터 공간 데이타의 효율적 전송을 위한 최적화 기법 (An Optimization Strategy for Vector Spatial Data Transmission onover the Internet)

  • Liang Chen;Chung-Ho Lee;Hae-Young Bae
    • 한국정보과학회논문지:데이타베이스
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    • 제30권3호
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    • pp.273-285
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    • 2003

  • 일반적으로 공간 벡터 데이타는 래스터 데이타에 비해 많은 정보를 포함하고 있으므로, 좀 더 융통적이고 효율적으로 데이타에 대한 처리가 가능하다. 그러나 인터넷을 통한 공간 벡터 데이타의 조작 시 해결해야 할 문제로 좁은 대역폭을 갖는 인터넷에서 크기가 크고 복잡한 벡터 데이타를 어떻게 효율적으로 전송하는가 라는 문제이다. 본 논문은 좁은 대역폭을 갖는 인터넷을 통한 공간 벡터 데이타를 효율적으로 전송하기 위한 새로운 전송 기법인 스케일에 기반한 전송 기법을 제안한다. 제안된 기법의 아이디어는 보여질수 있는 것만을 전송하는 것이다. 특정 스케일에서 일부 피쳐만이 사용자에게 보여지므로, 자연히 스케일은 공간 피쳐와 연관된 요소이다. 제안된 기법은 웨이블릿에 기반한 지도 일반화 알고리즘을 통해 공간 객체 중에서 출력되는 스케일에 따라 보여질 필요가 없는 피쳐들을 필터링하고, 보여지는 피쳐만을 최종적으로 전송한다. 본 논문에서는 실험을 통해 제안된 기법을 사용하는 경우, 개개의 공간 연산들에 대한 응답 시간이 대체적으로 향상됨을 보인다.

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